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Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
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1

Transport Energy Use and Population Density  

NLE Websites -- All DOE Office Websites (Extended Search)

Transport Energy Use and Population Density Transport Energy Use and Population Density Speaker(s): Masayoshi Tanishita Date: July 1, 2004 - 10:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Jonathan Sinton After Peter Newman and Jeffrey Kenworthy published "Cities and Automobile Dependence" in 1989, population density was brought to public attention as an important factor to explain transport mobility and energy use. However, several related issues still remain open: Is an increase in population density more effective than rising gas prices in reducing transport energy use? How much does per capita transport energy use change as population density in cities changes? And what kind of factors influence changes in population density? In this presentation, using city-level data in the US, Japan and other countries, the population-density elasticity of

2

Population Density Population density (persons per square kilometer) layers, for 1990  

E-Print Network (OSTI)

Population Density Africa Population density (persons per square kilometer) layers, for 1990 the 12 population density classes. Source information: http://sedac.ciesin.columbia.edu/gpw/. ´ Robinson://sedac.ciesin.columbia.edu/place/ Publish Date: 03/13/07 0 1,000 km Population Density 2000 0 Persons \\ Sq.Km 0-2 Persons \\ Sq.Km 2

Columbia University

3

Fact #661: February 7, 2011 Population Density  

Energy.gov (U.S. Department of Energy (DOE))

The density of the population in the U.S., measured as the number of people per square mile, affects the way goods and people are transported. The newly released 2010 Census data show that, on a...

4

Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density  

NLE Websites -- All DOE Office Websites (Extended Search)

1: February 7, 1: February 7, 2011 Population Density to someone by E-mail Share Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on Facebook Tweet about Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on Twitter Bookmark Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on Google Bookmark Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on Delicious Rank Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on Digg Find More places to share Vehicle Technologies Office: Fact #661: February 7, 2011 Population Density on AddThis.com... Fact #661: February 7, 2011 Population Density The density of the population in the U.S., measured as the number of people

5

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

E-Print Network (OSTI)

relatively high population density (much of it living inland) and small rivers this is an important of filters such as activated carbon. The main problem is one of scale. A city such as Northampton, UK energy intensive drinking water purification technology in such a case would be an expensive undertaking

Darton, Richard

6

Influence of landscape elements on population densities and habitat use of three small-mammal species.  

SciTech Connect

Mabry, K.E., E.A. Dreelin, and G.W. Barrett. 2003. Influence of landscape elements on population densities and habitat use of three small-mammal species. J. Mammology. 84(1):20-25. Corridor effects on population densities and habitat use of 3 small mammal species were assessed in an experimentally fragmented landscape. Corridor presence did not have a statistically significant effect on population densities of cotton rats or cotton mice; however, a significant effect was observed for old-field mice. The results suggest that landscape fragmentation and habitat structure may have varying effects on population densities of different species.

Mabry, Karen, E.; Dreelin, Erin, A.; Barrett, Gary, W.

2003-01-01T23:59:59.000Z

7

Density Functional Theory Study of Oxygen Reduction Activity...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

8

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

9

Unbiased estimators of wildlife population densities using aural information  

E-Print Network (OSTI)

. Using L' = 1. 99, and p = 1/3, from (30) an estimate of the density is n 108. 85 f A ] 99(3)(4QQQ)(] /3) . 0136 dove pairs/acre s = 1. 36 dove pairs/100 acres. 25 This is the same estimate we obtained using DI. The reason for this is explained...(7. 50) 1. 12 ? (2 422) (3) (40) (1(3) (0. 96, l. 28) 3. 4 Suggestions for Improvements At present, the call-count technique for estimating the density of mourning doves seems satisfactory for establishing a relative density index, but to get a good...

Durland, Eric Newton

1969-01-01T23:59:59.000Z

10

Estimates of cetacean abundance, biomass, and population density are  

E-Print Network (OSTI)

; Carretta et al., 2005), and fish- eries catch many of the same species that cetaceans consume (Trites et al be affected by anthropogenic sound (e.g., sonar, ship noise, and seismic surveys) and cli- mate change by the Scientific Editor. Fish. Bull. 105:509­526 (2007). Abstract--The abundance and popu- lation density

11

Population characteristics and diets of two white-tailed deer herds with contrasting densities  

E-Print Network (OSTI)

POPULATION CHARACTERISTICS AND DIETS QF TWQ WHITE-TAILED DEER HERDS WITH CONTRASTING DENSITIES A Thesis by DAVID ALAN TILTON Submitted to the Gnaduace College of Texas AAM Univer sity in partial fulfillmer. t of the r equi' ements... for the degree of' MASTER OF SCIENCE December l9B5 Major Subject: Wildlife and Fisheries Sciences POPULATION CHARACTERISTICS AND DIETS OF TWO WHITE-TAILED DEER HERDS WITH CONTRASTING DENSITIES A Thesis by DAVID ALAN TILTON Approved as to style...

Tilton, David Alan

2012-06-07T23:59:59.000Z

12

Effects of Landscape Manipulation on Population Densities, Habitat Utilization, Home Ranges, and Movements of Three Small Mammal Species  

SciTech Connect

No significant differences were found in the population densities of any species in experimentally fragmented landscape. However, trends in population densities indicate that connected patches usually support higher densities of cotton rats, isolated patches supported higher densities of old-field mice. No significant trends in population densities were observed for cotton mice. Cotton mice were captured more often in corridors, while old-field mice were captured more frequently in the interior. Results suggest landscape fragmentation has less of an effect on cotton mice-a habitat generalist.

Mabry, K.E.

2001-07-01T23:59:59.000Z

13

Activities of the High Energy Density Laboratory Plasmas  

E-Print Network (OSTI)

Activities of the High Energy Density Laboratory Plasmas FESAC Panel R. Betti FPA Meeting December #12;F. Beg (UCSD) B. Remington (LLNL) R. Betti (UR) (chair) R. Davidson (Princeton) P. Drake (U. Betti (UR) D. Hammer (Cornell) G. Logan (LBNL) D. Meyerhofer (UR) J. Sethian (NRL) R. Siemon (UNR) IFE

14

Influence of row spacing, population density and irrigation on phenology, yield and fiber properties of three upland cotton varieties  

E-Print Network (OSTI)

INFLUENCE OF ROW SPACING, POPULATION DENSITY AND IRRIGATION ON PHENOLOGY, YIELD AND FIBER PROPERTIES OF THREE UPLAND COTTON VARIETIES A Thesis by WILLIAM DAVID HAMILTON Submitted to the Graduate College of Texas ASM University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1982 Major Subject: Agronomy INFLUENCE OF ROW SPACING, POPULATION DENSITY AND IRRIGATION ON PHENOLOGY, YIELD AND FIBER PROPERTIES OF THREE UPLAND COTTON VARIETIES A Thesis...

Hamilton, William David

2012-06-07T23:59:59.000Z

15

The Space Density of Compton-Thick Active Galactic Nucleus and the X-Ray Background  

Science Journals Connector (OSTI)

We constrain the number density and evolution of Compton-thick (CT) active galactic nuclei (AGNs). In the local universe, we use the wide-area surveys from the Swift and INTEGRAL satellites, while for high redshifts we explore candidate selections based on a combination of X-ray and mid-infrared (mid-IR) parameters. We find a significantly lower space density of CT AGNs in the local universe than expected from published AGN population synthesis models to explain the X-ray background (XRB). This can be explained by the numerous degeneracies in the parameters of those models; we use the high-energy surveys described here to remove those degeneracies. We show that only direct observations of CT AGNs can currently constrain the number of heavily obscured supermassive black holes. At high redshift, the inclusion of IR-selected CT AGN candidates leads to a much higher space density, implying (1) a different (steeper) evolution for these sources compared to less-obscured AGNs, (2) that the IR selection includes a large number of interlopers, and/or (3) that there is a large number of reflection-dominated AGNs missed in the INTEGRAL and Swift observations. The contribution of CT AGN to the XRB is small, ~9%, with a comparable contribution to the total cosmic accretion, unless reflection-dominated CT AGNs significantly outnumber transmission-dominated CT AGNs, in which case their contribution can be much higher. Using estimates derived here for the accretion luminosity over cosmic time, we estimate the local mass density in supermassive black holes and find a good agreement with available constraints for an accretion efficiency of ~10%. Transmission-dominated CT AGNs contribute only ~8% to total black hole growth.

E. Treister; C. Megan Urry; Shanil Virani

2009-01-01T23:59:59.000Z

16

Identification of lipolytic activity in a multitrophic population grown in wool-scour effluent  

Science Journals Connector (OSTI)

A multitrophic population established in wool-scour effluent produced esterase activity with specificity to...p-nitrophenol palmitate. The activity was present in both the extracellular and cell membrane fraction...

M. -C. Brahimi-Horn; C. A. Mickelson

1991-07-01T23:59:59.000Z

17

Emergent multicellular life cycles in filamentous bacteria owing to density-dependent population dynamics  

Science Journals Connector (OSTI)

...which a given fixed carrying capacity is achieved and ask the question...population reaches its carrying capacity can be different from the rate...autonomously fix carbon using solar light as an energy source...stabilized at its carrying capacity. At each iteration, the following...

2011-01-01T23:59:59.000Z

18

Predicting the Appraised Unit Value of Unimproved Parcels in San Francisco, CA Using LEED Sustainable Site Credit Criteria, Parcel area, Zoning, and Population Density  

E-Print Network (OSTI)

to explore the economic influence on the market value of undeveloped land through an analysis of public transportation in San Francisco, CA. Population density and area of each parcel are the factors considered to make the predictive model more powerful...

Cho, Hyun Jeong

2012-10-19T23:59:59.000Z

19

Density Functional Calculations of ATP Systems. 2. ATP Hydrolysis at the Active Site of J. Akola and R. O. Jones*  

E-Print Network (OSTI)

Density Functional Calculations of ATP Systems. 2. ATP Hydrolysis at the Active Site of Actin J-triphosphate (ATP) at the active site of actin has been studied using density functional calculations. The active site is modeled by the triphosphate tail of ATP, an Mg cation, surrounding water molecules

20

A density functional theory model of mechanically activated silyl ester hydrolysis  

SciTech Connect

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.

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 fr Physikalische Chemie, Christian-Albrechts-Universitt zu Kiel, Olshausenstrae 40, 24098 Kiel (Germany); Center for Nanoscience (CeNS), Geschwister-Scholl-Platz 1, 80539 Munich (Germany); Beyer, Martin K. [Institut fr Physikalische Chemie, Christian-Albrechts-Universitt zu Kiel, Olshausenstrae 40, 24098 Kiel (Germany) [Institut fr Physikalische Chemie, Christian-Albrechts-Universitt zu Kiel, Olshausenstrae 40, 24098 Kiel (Germany); Institut fr Ionenphysik und Angewandte Physik, Leopold-Franzens-Universitt Innsbruck, Technikerstrae 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

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

SciTech Connect

The structure, stability, and catalytic activity of a number of single- and double-wall platinum (n,m) nanotubes ranging in diameter from 0.3 to 2.0 nm were studied using plane-wave based density functional theory in the gas phase and water environment. The change in the catalytic activity toward the oxygen reduction reaction (ORR) with the size and chirality of the nanotube was studied by calculating equilibrium adsorption potentials for ORR intermediates and by constructing free energy diagrams in the ORR dissociative mechanism network. In addition, the stability of the platinum nanotubes is investigated in terms of electrochemical dissolution potentials and by determining the most stable state of the material as a function of pH and potential, as represented in Pourbaix diagrams. Our results show that the catalytic activity and the stability toward electrochemical dissolution depend greatly on the diameter and chirality of the nanotube. On the basis of the estimated overpotentials for ORR, we conclude that smaller, approximately 0.5 nm in diameter single-wall platinum nanotubes consistently show a huge, up to 400 mV larger overpotential than platinum, indicating very poor catalytic activity toward ORR. This is the result of substantial structural changes induced by the adsorption of any chemical species on these tubes. Single-wall n = m platinum nanotubes with a diameter larger than 1 nm have smaller ORR overpotentials than bulk platinum for up to 180 mV and thus show improved catalytic activity relative to bulk. We also predict that these nanotubes can endure the highest cell potentials but dissolution potentials are still for 110 mV lower than for the bulk, indicating a possible corrosion problem.

Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

2012-07-13T23:59:59.000Z

22

Pore Size Analysis of Activated Carbons from Argon and Nitrogen Porosimetry Using Density Functional Theory  

E-Print Network (OSTI)

Form: December 28, 1999 We present isotherms calculated from density functional theory. A similar set of density functional theory isotherms, previously reported for nitrogen adsorption on carbon Functional Theory Robert J. Dombrowski, Daniel R. Hyduke, and Christian M. Lastoskie* Department of Chemical

Lastoskie, Christian M.

23

POPULATION DENSITY, 2000 Population density measures the number  

E-Print Network (OSTI)

´ GUADELOUPE 0 25 50 km NETHERLAND ANTILLES NETHERLAND ANTILLES ST. KITTS NEVIS Copyright 2009. The Trustees

Columbia University

24

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

E-Print Network (OSTI)

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

Nyman, John

25

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

E-Print Network (OSTI)

Copper nanocrystal modified activated carbon for supercapacitors with enhanced volumetric energy of copper nanocrystals in AC has little effect on the surface area and porosity of activated carbon. copper nanocrystals improves the electrical conductivity of the carbon network.

Cao, Guozhong

26

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

SciTech Connect

We used density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.51.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, non-hollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity toward the oxygen reduction reaction of platinum nanowires was assessed by studying the change in the chemisorption energies of oxygen, hydroxyl, and hydroperoxyl groups, induced by converting the nanotube models to nanowires. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Single-wall nanotubes and platinum nanowires with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

2013-03-14T23:59:59.000Z

27

NOAA'sSTATEOFTHECOAST National Coastal Population Report  

E-Print Network (OSTI)

Shoreline Counties Population Population Density Age Race Hispanic Origin Education Attainment Household Population Density Age Race Hispanic Origin Education Attainment Household Income Seasonal Housing Building

28

Induction of macrophage antitumor activity by acetylated low density lipoprotein containing lipophilic muramyl tripeptide  

Science Journals Connector (OSTI)

...muramyl tripeptide J M Shaw W S Futch, Jr L B Schook Department of...macrophage activation) J. MICHAEL SHAW*t, WILLIAM S. FUTCH, JRO, AND LAWRENCE B. SCHOOK...Yanovich, S., Iwanik, M., Futch, W. S., Rosowsky, A...

J M Shaw; W S Futch; Jr; L B Schook

1988-01-01T23:59:59.000Z

29

Induction of macrophage antitumor activity by acetylated low density lipoprotein containing lipophilic muramyl tripeptide  

Science Journals Connector (OSTI)

...lipophilic muramyl tripeptide J M Shaw W S Futch, Jr L B Schook Department of Animal Sciences...activation) J. MICHAEL SHAW*t, WILLIAM S. FUTCH, JRO, AND LAWRENCE B. SCHOOK?? ?Laboratory...V., Yanovich, S., Iwanik, M., Futch, W. S., Rosowsky, A. & Schook, L...

J M Shaw; W S Futch; Jr; L B Schook

1988-01-01T23:59:59.000Z

30

The density-of-states concept versus the experimentally determined distribution of activation energies  

SciTech Connect

Random fluctuations of localized state energies will result in thermal release of carriers trapped in those states at shorter times than would be observed from a stationary distribution of the same energies. An experimentally observed distribution of activation energies will hence differ from the distribution of average energies of the states involved. It will also be temperature-dependent. In a-Si:H, low-frequency fluctuations with a spectrum comparable to the one of 1/f noise, can account for the measured temperature dependence of the distribution. They also explain the apparent shift in localized-state energy under steady-state illumination.

Adriaenssens, G.J.; Arkhipov, V.I. [Katholieke Univ. Leuven, Heverlee-Leuven (Belgium). Lab. voor Halfgeleiderfysica

1996-12-31T23:59:59.000Z

31

Modeling high-pressure adsorption of gas mixtures on activated carbon and coal using a simplified local-density model  

SciTech Connect

The simplified local-density (SLD) theory was investigated regarding its ability to provide accurate representations and predictions of high-pressure supercritical adsorption isotherms encountered in coalbed methane (CBM) recovery and CO{sub 2} sequestration. Attention was focused on the ability of the SLD theory to predict mixed-gas adsorption solely on the basis of information from pure gas isotherms using a modified Peng-Robinson (PR) equation of state (EOS). An extensive set of high-pressure adsorption measurements was used in this evaluation. These measurements included pure and binary mixture adsorption measurements for several gas compositions up to 14 MPa for Calgon F-400 activated carbon and three water-moistened coals. Also included were ternary measurements for the activated carbon and one coal. For the adsorption of methane, nitrogen, and CO{sub 2} on dry activated carbon, the SLD-PR can predict the component mixture adsorption within about 2.2 times the experimental uncertainty on average solely on the basis of pure-component adsorption isotherms. For the adsorption of methane, nitrogen, and CO{sub 2} on two of the three wet coals, the SLD-PR model can predict the component adsorption within the experimental uncertainties on average for all feed fractions (nominally molar compositions of 20/80, 40/60, 60/40, and 80/20) of the three binary gas mixture combinations, although predictions for some specific feed fractions are outside of their experimental uncertainties.

Fitzgerald, J.E.; Robinson, R.L.; Gasem, K.A.M. [Oklahoma State University, Stillwater, OK (United States). School of Chemical Engineering

2006-11-07T23:59:59.000Z

32

A large population of mid-infrared selected, obscured active galaxies in the Bootes field  

E-Print Network (OSTI)

We identify a population of 640 obscured and 839 unobscured AGNs at redshifts 0.7Bootes. We select AGNs on the basis of Spitzer IRAC colors obtained by the IRAC Shallow Survey. Redshifts are obtained from optical spectroscopy or photometric redshift estimators. We classify the IR-selected AGNs as IRAGN 1 (unobscured) and IRAGN 2 (obscured) using a simple criterion based on the observed optical to mid-IR color, with a selection boundary of R-[4.5]=6.1, where R and [4.5] are the Vega magnitudes in the R and IRAC 4.5 micron bands, respectively. We verify this selection using X-ray stacking analyses with data from the Chandra XBootes survey, as well as optical photometry from NDWFS and spectroscopy from MMT/AGES. We show that (1) these sources are indeed AGNs, and (2) the optical/IR color selection separates obscured sources (with average N_H~3x10^22 cm^-2 obtained from X-ray hardness ratios, and optical colors and morphologies typical of galaxies) and unobscured sources (with no X-ray absorption, and quasar colors and morphologies), with a reliability of >~80%. The observed numbers of IRAGNs are comparable to predictions from previous X-ray, optical, and IR luminosity functions, for the given redshifts and IRAC flux limits. We observe a bimodal distribution in R-[4.5] color, suggesting that luminous IR-selected AGNs have either low or significant dust extinction, which may have implications for models of AGN obscuration.

R. C. Hickox; C. Jones; W. R. Forman; S. S. Murray; M. Brodwin; M. J. I. Brown; P. R. Eisenhardt; D. Stern; C. S. Kochanek; D. Eisenstein; R. J. Cool; B. T. Jannuzi; A. Dey; K. Brand; V. Gorjian; N. Caldwell

2007-08-27T23:59:59.000Z

33

STELLAR POPULATIONS IN THE CENTRAL 0.5 pc OF THE GALAXY. I. A NEW METHOD FOR CONSTRUCTING LUMINOSITY FUNCTIONS AND SURFACE-DENSITY PROFILES  

SciTech Connect

We present new high angular resolution near-infrared spectroscopic observations of the nuclear star cluster surrounding the Milky Way's central supermassive black hole. Using the integral-field spectrograph OSIRIS on Keck II behind the laser-guide-star adaptive optics system, this spectroscopic survey enables us to separate early-type (young, 4-6 Myr) and late-type (old, >1 Gyr) stars with a completeness of 50% down to K' = 15.5 mag, which corresponds to {approx}10 M {sub Sun} for the early-type stars. This work increases the radial extent of reported OSIRIS/Keck measurements by more than a factor of three from 4'' to 14'' (0.16 to 0.56 pc), along the projected disk of young stars. For our analysis, we implement a new method of completeness correction using a combination of star-planting simulations and Bayesian inference. We assign probabilities for the spectral type of every source detected in deep imaging down to K' = 15.5 mag using information from spectra, simulations, number counts, and the distribution of stars. The inferred radial surface-density profiles, {Sigma}(R){proportional_to}R {sup -{Gamma}}, for the young stars and late-type giants are consistent with earlier results ({Gamma}{sub early} = 0.93 {+-} 0.09, {Gamma}{sub late} = 0.16 {+-} 0.07). The late-type surface-density profile is approximately flat out to the edge of the survey. While the late-type stellar luminosity function is consistent with the Galactic bulge, the completeness-corrected luminosity function of the early-type stars has significantly more young stars at faint magnitudes compared with previous surveys with similar depth. This luminosity function indicates that the corresponding mass function of the young stars is likely less top-heavy than that inferred from previous surveys.

Do, T.; Martinez, G. D. [Physics and Astronomy Department, University of California, Irvine, CA 92697 (United States)] [Physics and Astronomy Department, University of California, Irvine, CA 92697 (United States); Lu, J. R. [Institute for Astronomy, University of Hawaii, HI (United States)] [Institute for Astronomy, University of Hawaii, HI (United States); Ghez, A. M.; Morris, M. R.; Yelda, S. [Physics and Astronomy Department, University of California, Los Angeles, CA 90095-1547 (United States)] [Physics and Astronomy Department, University of California, Los Angeles, CA 90095-1547 (United States); Wright, S. A. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto M5S 3H4, ON (Canada)] [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto M5S 3H4, ON (Canada); Matthews, K., E-mail: do@di.utoronto.ca [Department of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA (United States)

2013-02-20T23:59:59.000Z

34

The transfer of very low density lipoprotein-associated phospholipids to activated human platelets depends upon cytosolic phospholipase A2 activity  

E-Print Network (OSTI)

the activity of PLA2 that cleave fatty acids from the sn2 position of PL. In particular, the cytosolic PLA2 (cPLA2) reaction favors the release of arachidonic acid which is the precursor of prostaglandins

Boyer, Edmond

35

Effects of Season and Host Physiological State on the Diversity, Density, and Activity of the Arctic Ground Squirrel Cecal Microbiota  

Science Journals Connector (OSTI)

...EM and GC Burton. 1970. The effect of hibernation on the caecal...CL and BM Barnes. 2000. Effects of ambient temperature on metabolic...bioinformatics/btp636 . 29. Price, MN , PS Dehal and AP Arkin...squirrels: a strong litter effect across the first active season...

Timothy J. Stevenson; Khrystyne N. Duddleston; C. Loren Buck

2014-07-07T23:59:59.000Z

36

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

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.

Harpenau, Evan M

2013-10-10T23:59:59.000Z

37

Student Activities Student Activities  

E-Print Network (OSTI)

with Solar Energy? Activity B How do Atmospheres Produce their Effect Upon Surface Temperatures? Activity C and populations found in developing countries in Asia, Africa and Latin America. Figure 4.3 illustrates the actual

38

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)

Standards for Nuclear Power Plants," by A.V. Nero and Y.C.Response Planning for Nuclear Power Plants in California,"Densities Surrounding Nuclear Power Plants," by A.V. Nero,

Nero, jA.V.

2010-01-01T23:59:59.000Z

39
40

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

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.

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

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Activities  

Energy.gov (U.S. Department of Energy (DOE))

Activities and events provide Residential Network members the opportunity to discuss similar needs and challenges, and to collectively identify effective strategies and useful resources.

42

E-Print Network 3.0 - adult urban population Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

is found. The Neoclassic... Population Density model...126 18a. ... Source: Lund, Jay R. - Department of Civil and Environmental Engineering,...

43

Density Log | Open Energy Information  

Open Energy Info (EERE)

Density Log Density Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Density Log Details Activities (6) Areas (6) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: provides data on the bulk density of the rock surrounding the well Stratigraphic/Structural: Stratigraphic correlation between well bores. Hydrological: Porosity of the formations loggesd can be calculated for the Density log andprovide an indication potential aquifers. Thermal: Cost Information Low-End Estimate (USD): 0.4040 centUSD 4.0e-4 kUSD 4.0e-7 MUSD 4.0e-10 TUSD / foot Median Estimate (USD): 0.6868 centUSD

44

Studies of protein adsorption on implant materials in relation to biofilm formation I. Activity of Pseudomonas aeruginosa on Polypropylene and High density Polyethylene in presence of serum albumin  

E-Print Network (OSTI)

The surface of biomaterials used as implants are highly susceptible to bacterial colonization and subsequent infection. The amount of protein adsorption on biomaterials, among other factors, can affect the nature and quality of biofilms formed on them. The variation in the adsorption time of the protein on the biomaterial surface produces a phenotypic change in the bacteria by alteration of the production of EPS (exoplysaccharide) matrix. Knowledge of the effects of protein adsorption on implant infection will be very useful in understanding the chemistry of the biomaterial surfaces, which can deter the formation of biofilms. It is observed that the adsorption of BSA on the biomaterial surfaces increases with time and concentration, irrespective of their type and the nature of the EPS matrix of the bacterial biofilm is dependent on the amount of protein adsorbed on the biomaterial surface. The adsorption of protein (BSA) on the biomaterials, polypropylene (PP) and high density polyethylene (HDPE) has been stu...

Sinha, S Dutta; Maity, P K; Tarafdar, S; Moulik, S P

2014-01-01T23:59:59.000Z

45

Fluctuations and information filtering in coupled populations of spiking neurons with adaptation  

Science Journals Connector (OSTI)

Finite-sized populations of spiking elements are fundamental to brain function but also are used in many areas of physics. Here we present a theory of the dynamics of finite-sized populations of spiking units, based on a quasirenewal description of neurons with adaptation. We derive an integral equation with colored noise that governs the stochastic dynamics of the population activity in response to time-dependent stimulation and calculate the spectral density in the asynchronous state. We show that systems of coupled populations with adaptation can generate a frequency band in which sensory information is preferentially encoded. The theory is applicable to fully as well as randomly connected networks and to leaky integrate-and-fire as well as to generalized spiking neurons with adaptation on multiple time scales.

Moritz Deger; Tilo Schwalger; Richard Naud; Wulfram Gerstner

2014-12-01T23:59:59.000Z

46

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

NLE Websites -- All DOE Office Websites (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...

47

Studies of protein adsorption on implant materials in relation to biofilm formation I. Activity of Pseudomonas aeruginosa on Polypropylene and High density Polyethylene in presence of serum albumin  

E-Print Network (OSTI)

The surface of biomaterials used as implants are highly susceptible to bacterial colonization and subsequent infection. The amount of protein adsorption on biomaterials, among other factors, can affect the nature and quality of biofilms formed on them. The variation in the adsorption time of the protein on the biomaterial surface produces a phenotypic change in the bacteria by alteration of the production of EPS (exoplysaccharide) matrix. Knowledge of the effects of protein adsorption on implant infection will be very useful in understanding the chemistry of the biomaterial surfaces, which can deter the formation of biofilms. It is observed that the adsorption of BSA on the biomaterial surfaces increases with time and concentration, irrespective of their type and the nature of the EPS matrix of the bacterial biofilm is dependent on the amount of protein adsorbed on the biomaterial surface. The adsorption of protein (BSA) on the biomaterials, polypropylene (PP) and high density polyethylene (HDPE) has been studied and the formation of the biofilms of Pseudomonas aeruginosa on them has been examined.

S Dutta Sinha; Susmita Chatterjee; P. K. Maity; S. Tarafdar; S. P. Moulik

2014-11-19T23:59:59.000Z

48

Formation of an internal transport barrier and magnetohydrodynamic activity in experiments with the controlled density of rational magnetic surfaces in the T-10 Tokamak  

SciTech Connect

Results are presented from experiments on the formation of an internal electron transport barrier near the q = 1.5 rational surface in the T-10 tokamak. The experiments were carried out in the regime with off-axis electron cyclotron resonance (ECR) heating followed by a fast plasma current ramp-up. After suppressing sawtooth oscillations by off-axis ECR heating, an internal transport barrier began to form near the q = 1.5 rational surface. In the phase of the current ramp-up, the quality of the transport barrier improved; as a result, the plasma energy confinement time increased 22.5 times. The intentionally produced flattening of the profile of the safety factor q(r) insignificantly affected magnetohydrodynamic activity in the plasma column in spite of the theoretical possibility of formation of substantial m/n = 3/2 and 2/1 magnetic islands. Conditions are discussed under which the flattening of the profile of the safety factor q near low-order rational surfaces leads to the formation of either an internal transport barrier or the development of an island magnetic structure induced by tearing modes.

Razumova, K. A., E-mail: razumova@nfi.kiae.ru; Andreev, V. F.; Belbas, I. S.; Gorshkov, A. V.; Dnestrovskij, A. Yu.; Dyabilin, K. S.; Kislov, A. Ya.; Lysenko, S. E.; Notkin, G. E.; Timchenko, N. N.; Chudnovskiy, A. N.; Shelukhin, D. A. [National Research Centre Kurchatov Institute (Russian Federation)] [National Research Centre Kurchatov Institute (Russian Federation)

2013-09-15T23:59:59.000Z

49

Laboratory Density Functionals  

E-Print Network (OSTI)

We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.

B. G. Giraud

2007-07-26T23:59:59.000Z

50

Population stability, cooperation, and the invasibility of the human species  

E-Print Network (OSTI)

a mechanism for these outcomes by modifying a simple density-dependent population model to allow varying populations expanded out of Africa and spread rapidly across the majority of the earth's land surfacePopulation stability, cooperation, and the invasibility of the human species Marcus J. Hamiltona

Brown, James H.

51

Ecological factors and human threats both drive wildfowl population declines  

E-Print Network (OSTI)

; human population density. Correspondence Peter R. Long, Department of Biology and Biochemistry, Africa and Asia. Second, we use phylogenetic comparative analyses to test whether population size, globalEcological factors and human threats both drive wildfowl population declines P. R. Long1 , T. Sz

52

activities  

NLE Websites -- All DOE Office Websites (Extended Search)

Detecting Things We Cannot See: Learning the Concepts of Control and Detecting Things We Cannot See: Learning the Concepts of Control and Variable in an Experiment Submitted by Anita Brook-Dupree, 1996 TRAC teacher at Fermilab, Teacher, Alternative Middle Years School, Philadelphia, PA. Particle physicists at Fermilab in Batavia, Illinois are faced with the problem of detecting the presence of sub-atomic particles they cannot see. During my summer as a TRAC teacher at Fermilab, I tried to think of ways to teach middle school students about things we cannot see. I want to thank my nine-year-old daughter Gia for the idea for the following activity. I was lamenting that I could not come up with ideas of how to relate the work of Fermilab scientists to anything that my students would understand. Then I was reminded by my daughter, that when I brought her to school on the

53

Overlap population density as an index of bond strength  

E-Print Network (OSTI)

be eliminated. This is done by carrying out an orthogonal transformdtion on b, witn a known matrix U, viz. D = UAU' (10) Next~ M is constructed vis, the equation: M=V'D 'U (11) M transforms b to the unit matrix X: (12) Since: I ~1 MdM = U 'D PhU 'D U... on molecules of the same chemical i'amily as those under study, viz, R2-NN02, D. Thermal Decomposition of Nitramides Although estimates of the energies of bonds other than N-N, B?G. Gowcnlock, P. Jones and J. R. Majer~ Trans. Faraday Soc. ~7 23 (1981) RE...

Gallagher, Michael James

2012-06-07T23:59:59.000Z

54

Rock Density | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Rock Density Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Rock Density Details Activities (2) Areas (2) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Density of different lithologic units. Stratigraphic/Structural: Hydrological: Thermal: Cost Information Low-End Estimate (USD): 10.001,000 centUSD 0.01 kUSD 1.0e-5 MUSD 1.0e-8 TUSD / sample

55

Separation of carbon nanotubes in density gradients  

DOE Patents (OSTI)

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2012-02-07T23:59:59.000Z

56

Separation of carbon nanotubes in density gradients  

DOE Patents (OSTI)

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2010-02-16T23:59:59.000Z

57

Symmetric Density Functionals  

E-Print Network (OSTI)

Variations in distinct restricted spaces of wave functions generate distinct density functionals. In particular, angular momentum projected Slater determinants define a new density functional, compatible simultaneously with angular momentum quantum number and mean field descriptions.

B. G. Giraud

2005-07-13T23:59:59.000Z

58

Density measurements Viscosity measurements  

E-Print Network (OSTI)

Density measurements Viscosity measurements Temperature measurements Pressure measurements Flow rate measurements Velocity measurements Sensors How to measure fluid flow properties ? Am´elie Danlos Ravelet Experimental methods for fluid flows: an introduction #12;Density measurements Viscosity

Ravelet, Florent

59

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

SciTech Connect

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.

Crone, E.E.

1995-11-08T23:59:59.000Z

60

ATMOSPHERIC DENSITY ESTIMATION USING SATELLITE PRECISION ORBIT EPHEMERIDES  

E-Print Network (OSTI)

The current atmospheric density models are not capable enough to accurately model the atmospheric density, which varies continuously in the upper atmosphere mainly due to the changes in solar and geomagnetic activity. Inaccurate atmospheric modeling...

Arudra, Anoop Kumar

2011-04-22T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Further Developments in Orbit Ephemeris Derived Neutral Density  

E-Print Network (OSTI)

effect the unmodeled density variations have on orbit propagation. These results are also binned by solar and geomagnetic activity level. The primary input into the orbit determination scheme used to produce the POE derived density estimates is a...

Locke, Travis Cole

2012-12-31T23:59:59.000Z

62

Independent optical excitation of distinct neural populations  

E-Print Network (OSTI)

Optogenetic tools enable examination of how specific cell types contribute to brain circuit functions. A long-standing question is whether it is possible to independently activate two distinct neural populations in mammalian ...

Klapoetke, Nathan Cao

63

Population dynamics of the Colorado potato beetle (coleoptera:chrysomelidae) in western Massachusetts  

Science Journals Connector (OSTI)

Population trends for first-and second-generation Colorado potato beetle (CPB),Leptimtarsa decemlineata (Say), on potato in western Massachusetts were examined using density estimates obtained...

Robert H. Voss; David N. Ferro

1992-08-01T23:59:59.000Z

64

Inner magnetosphere plasma densities  

E-Print Network (OSTI)

The radio plasma imager (RPI) on the IMAGE satellite performs radio sounding in the magnetosphere, transmitting coded signals stepping through the frequency range of interest and receiving the returned echoes. The measurements provide the echo amplitude as a function of frequency and echo delay time on a so-called plasmagram. A newly developed algorithm inverts THE echo traces on a plasmagram to electron density spatial distributions. Based on these observed density distributions, an empirical model is constructed to describe the two-dimensional density distribution in the inner magnetosphere.

Reinisch, B W

2002-01-01T23:59:59.000Z

65

Rock Density At Alum Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

Rock Density At Alum Area (DOE GTP) Rock Density At Alum Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Rock Density At Alum Geothermal Area (DOE GTP) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Rock Density Activity Date Usefulness not indicated DOE-funding Unknown References (1 January 2011) GTP ARRA Spreadsheet Retrieved from "http://en.openei.org/w/index.php?title=Rock_Density_At_Alum_Area_(DOE_GTP)&oldid=402985" Categories: Exploration Activities DOE Funded Activities ARRA Funded Activities What links here Related changes Special pages Printable version Permanent link Browse properties About us Disclaimers Energy blogs Linked Data Developer services OpenEI partners with a broad range of international organizations to grow

66

Optimal Harvesting of Structured Populations*t WAYNE M. GETZ  

E-Print Network (OSTI)

density of the population [denoted by x(t)] satisfies a nonlinear ordinary differential equationOptimal Harvesting of Structured Populations*t WAYNE M. GETZ National Research Institute for Mathematical Sciences, CSIR, P.O. Box 395, Pretoria 0001, Republic of South Africa Received 18 April 1978

Getz, Wayne M.

67

Density Log at Fort Bliss Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

Fort Bliss Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Density Log at Fort Bliss Area (DOE GTP) Exploration Activity Details...

68

Density | OpenEI  

Open Energy Info (EERE)

Density Density Dataset Summary Description This dataset is part of a larger internal dataset at the National Renewable Energy Laboratory (NREL) that explores various characteristics of large solar electric (both PV and CSP) facilities around the United States. This dataset focuses on the land use characteristics for solar facilities that are either under construction or currently in operation. Source Land-Use Requirements for Solar Power Plants in the United States Date Released June 25th, 2013 (5 months ago) Date Updated Unknown Keywords acres area average concentrating solar power csp Density electric hectares km2 land land requirements land use land-use mean photovoltaic photovoltaics PV solar statistics Data application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon Master Solar Land Use Spreadsheet (xlsx, 1.5 MiB)

69

Single-Nucleon Densities  

NLE Websites -- All DOE Office Websites (Extended Search)

Densities Densities This web page presents single-nucleon densities calculated for a variety of nuclei in the range A=2-10 with some preliminary results for A=11,12. These are from variational Monte Carlo calculations (VMC) using the Argonne v18 two-nucleon and Urbana X three-nucleon potentials (AV18+UX). (Urbana X is intermediate between the Urbana IX and Illinois-7 models; it has the form of UIX supplemented with a two-pion S-wave piece, while the strengths of its terms are taken from the IL7 model. It does NOT have the three-pion-ring term of IL7.) These VMC wave functions are the starting trial functions for a number of recent Green's function Monte Carlo (GFMC) calculations: Brida, et al., Phys. Rev. C 84, 024319 (2011); McCutchan, et al., Phys. Rev. C 86, 024315 (2012);

70

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

SciTech Connect

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.

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

1988-12-31T23:59:59.000Z

71

Density Functional Theory for Superconductors  

E-Print Network (OSTI)

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

72

Relativistic Nuclear Energy Density Functionals  

Science Journals Connector (OSTI)

......research-article Articles Relativistic Nuclear Energy Density Functionals Dario Vretenar...196, 2012 137 Relativistic Nuclear Energy Density Functionals Dario Vretenar...and P. Ring 2. Relativistic nuclear energy density functionals Even though......

Dario Vretenar; Tamara Niksic; Peter Ring

2012-10-01T23:59:59.000Z

73

Using Density Equalizing Map Projection (DEMP) in Epidemiologic  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Density Equalizing Map Projection (DEMP) in Epidemiologic Using Density Equalizing Map Projection (DEMP) in Epidemiologic Surveillance: An Analysis of Female Breast Cancer Incidence in the San Francisco Bay Area Speaker(s): Christine Erdman Date: April 5, 2001 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: David Faulkner This study examined the spatial distribution of female breast cancer incidence in the San Francisco Bay Area (California, U.S.A.) in relation to various demographic variables using cartograms for control of population density. Using a cartogram technique known as density equalized map projection (DEMP), census tract boundaries of geopolitical maps are transformed such that the resultant census tract areas are proportional to their population at risk. With spatial confounding removed, the maps become

74

Energy in density gradient  

E-Print Network (OSTI)

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 ...

Vranjes, J

2015-01-01T23:59:59.000Z

75

Multiple density layered insulator  

DOE Patents (OSTI)

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.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

76

Population, Consumption & the Environment  

E-Print Network (OSTI)

12/11/2009 1 Population, Consumption & the Environment Alex de Sherbinin Center for International of carbon in 2001 · The ecological footprint, a composite measure of consumption measured in hectares kind of consumption is bad for the environment? 2. How are population dynamics and consumption linked

Columbia University

77

Population | OpenEI  

Open Energy Info (EERE)

Population Population Dataset Summary Description Total population (in millions) by country, 1980 to 2010. Compiled by Energy Information Administration (EIA). Source EIA Date Released Unknown Date Updated Unknown Keywords EIA Population world Data text/csv icon population_by_country_1980_2010millions.csv (csv, 59.1 KiB) Quality Metrics Level of Review Peer Reviewed Comment Temporal and Spatial Coverage Frequency Time Period 1980 - 2010 License License Other or unspecified, see optional comment below Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access Average vote Your vote Overall rating Average vote Your vote Comments Login or register to post comments If you rate this dataset, your published comment will include your rating.

78

Estimating abundance for a savanna elephant population using markresight methods: a case study for the Tembe  

E-Print Network (OSTI)

are difficult to count. Many elephant populations in Africa occur in such conditions. Estimates population size or densities for medium to large mammals living in wooded areas are poorly developed (CaroEstimating abundance for a savanna elephant population using mark­resight methods: a case study

Pretoria, University of

79

Assessing the distribution, habitat, and population size of the threatened Dupont's lark Chersophilus  

E-Print Network (OSTI)

North African range, as well as on its preferred habitat, population density and size. Fieldwork), with important populations believed to be present in the steppe-like habitat of North Africa (Cramp, 1988Assessing the distribution, habitat, and population size of the threatened Dupont's lark

Oñate, Juan J.

80

Gedanken densities and exact constraints in density functional theory  

SciTech Connect

Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGAs. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.

Perdew, John P. [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States) [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States); Ruzsinszky, Adrienn; Sun, Jianwei [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States)] [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Burke, Kieron [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)] [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

E-Print Network (OSTI)

increased linearly with increased population. Lodging increased approximately 2. 4X for each increase of 4, 000 ppa. (9, 884 pph. ). Stalk diameter showed a linear decrease with increasing populations which accounts for the increase in stalk breaking... (47) studied effect of corn population densities ranging from 2, 700 to 283, 00 ppa. They concluded that popu- lation density had no discernible effect on the root percentage. The maximum LAI (LAI = 20) was obtained from the densest population which...

Silapapun, Anek

2012-06-07T23:59:59.000Z

82

Population Trends and Prospects  

Science Journals Connector (OSTI)

...improve-ments in food availability per person, and today the actual number...population growth. Consequently, food production per person in most developing countries...is no improvement in staple food production, primarily cereal grain, in countries...

W. Parker Mauldin

1980-07-04T23:59:59.000Z

83

Populating the Whole Landscape  

E-Print Network (OSTI)

Every de Sitter vacuum can transition to every other de Sitter vacuum despite any obstacle, despite intervening anti-de Sitter sinks, despite not being connected by an instanton. Eternal inflation populates the whole landscape.

Adam R. Brown; Alex Dahlen

2012-02-19T23:59:59.000Z

84

High Energy Density Capacitors  

SciTech Connect

BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of todays 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.

None

2010-07-01T23:59:59.000Z

85

Longitudinal density monitor for the LHC  

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.

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

86

Longitudinal density monitor for the LHC  

Science Journals Connector (OSTI)

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 90ps. 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.

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

2012-03-23T23:59:59.000Z

87

Deriving Atmospheric Density Estimates Using Satellite Precision Orbit Ephemerides  

E-Print Network (OSTI)

Model regardless of solar and geomagnetic activity levels. The POE density estimates were obtained with the desired accuracy for a 10% variation in the ballistic coefficient used to initialize the process. Fit span length showed little influence...

Hiatt, Andrew Timothy

2009-01-01T23:59:59.000Z

88

Two Single-Nucleotide Polymorphisms with Linkage Disequilibrium in the Human Programmed Cell Death 5 Gene 5? Regulatory Region Affect Promoter Activity and the Susceptibility of Chronic Myelogenous Leukemia in Chinese Population  

Science Journals Connector (OSTI)

...Myelogenous Leukemia in Chinese Population Xi Ma 1 Guorui Ruan 4 Ying Wang 2 Qiyan Li 3 Ping Zhu 5 Ya-Zhen Qin 4 Jin-Lan Li 4 Yan-Rong Liu 4 Dalong Ma 1...Genet 1999;8:1443-9. 13 Zhang J, Jin X, Fang S, et al. The functional SNP...

Xi Ma; Guorui Ruan; Ying Wang; Qiyan Li; Ping Zhu; Ya-Zhen Qin; Jin-Lan Li; Yan-Rong Liu; Dalong Ma; and Hongshan Zhao

2005-12-15T23:59:59.000Z

89

Charge Density Wave Compounds  

NLE Websites -- All DOE Office Websites (Extended Search)

Fisher Research Group Fisher Research Group Layered Chalcogenides 29 February 2008 Controlling the Wave by Brad Plummer, SLAC Communications Stanford University researchers working in part at SSRL have discovered a novel set of properties pertaining to a compound of materials called tritellurides. These compounds, composed of three atoms of tellurium and a single atom of one of the rare earth elements, demonstrate unique electronic properties that can be controlled by altering the temperature of the material. The tritellurides display phenomena known as charge density waves (CDW). In a normal conductive metal, electrons persist in a "sea" wherein they are evenly distributed and equally available, or conductive. A CDW occurs under certain circumstances and causes the electrons to clump together, lowering their availability, and thereby lowering the compound's conductivity. Tellurium, when crystallized into quasi-two-dimensional planes and combined with rare earth elements, produces a material with CDWs that can be manipulated and controlled.

90

Nuclear energy density optimization  

Science Journals Connector (OSTI)

We carry out state-of-the-art optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov 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 unedf0 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.

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

2010-08-13T23:59:59.000Z

91

Density Functional Theory for Superconductors  

E-Print Network (OSTI)

Density Functional Theory for Superconductors N. N. LATHIOTAKIS,1,2 M. A. L. MARQUES,1,2,3 M. LU; density functional theory; critical temperature; exchange and correlation; phonon and theoretical chemistry is density functional theory (DFT). Its foundations were established in the mid-1960s

Gross, E.K.U.

92

Principles of Population Health Science Population Health 795  

E-Print Network (OSTI)

1 Principles of Population Health Science Population Health 795 A course in the Program in Population Health Fall 2012 University of Wisconsin-Madison, School of Medicine and Public Health The lecture in medicine and public health, inequities in health persist. Understanding health on a population level

Sheridan, Jennifer

93

DERIVATION AND OBSERVABILITY OF UPPER ATMOSPHERIC DENSITY VARIATIONS UTILIZING PRECISION ORBIT EPHEMERIDES  

E-Print Network (OSTI)

for these satellites. The POE derived densities showed marked improvement using these methods of comparison over the existing empirical density models for all examined time periods and solar and geomagnetic activity levels. The cross correlation values for the POE...

Lechtenberg, Travis Francis

2010-04-28T23:59:59.000Z

94

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

SciTech Connect

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.

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

95

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

96

Molecular population genetics and epidemiology of Ceratocystis fagacearum  

E-Print Network (OSTI)

and the other population represented a sexually active disease center. Three polymorphic RFLP loci were found. Only one population, Willow Springs, had more than 1 allele present at the RFLP loci. Very low levels of variation (G = 1, 1, and 11.69) were detected...

Ivors, Kelly Lynn

1995-01-01T23:59:59.000Z

97

RECOMMENDATIONS FOR THE MANAGEMENT OF THE MARINE TURTLE POPULATION S  

E-Print Network (OSTI)

RECOMMENDATIONS FOR THE MANAGEMENT OF THE MARINE TURTLE POPULATION S OF PULAU SIPADAN, SABAH Page EXECUTIVE SUMMARY 1 Introduction 1 Threats to the Turtles of Sipadan 1 Recommendations 3 . METHODOLOGY 6 2 .1 Description of the Nesting Beach 7 2 .2 Records of Turtle Nesting Density

Prestwich, Ken

98

ON THE TURTLE POPULATION S OF THE ISLANDS OF PAHANG  

E-Print Network (OSTI)

A REPORT ON THE TURTLE POPULATION S OF THE ISLANDS OF PAHANG AND SUGGESTIONS FOR THEIR MANAGEMENT 30423 / Telefax : 03-756-5594 #12;CONTENTS Page EXECUTIVE SUMMARY . . .. . 1 The Status of the Turtles DENSITY OF THE TURTLES 4 4 .1 Pulau Tioman 5 4 .1 .1 Beaches on the West Coast of Tioman 5 4 .1 .2

Prestwich, Ken

99

Climate Activity 1 Frontiers of Science Seminar Activity Following Broecker's First Lecture  

E-Print Network (OSTI)

. World Population. The reddest color corresponds to a population density of 1000 people per square populated (reddish) band crossing Africa just south of the Sahara desert. By correlating this region. The great rain forests of Brazil and equatorial Africa are dark green. The band of forests running across

Menke, William

100

Generation of Gaussian Density Fields  

E-Print Network (OSTI)

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.

Hugo Martel

2005-06-22T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Density Functional Theory (DFT) Simulated Annealing (SA)  

E-Print Network (OSTI)

. . . . . . . . 9 2009 #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory) % Lattice-Boltzmann (LBM) #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT) Simulated Annealing (SA) Monte Carlo &$ ' ' (GCMC

102

Density Log at Fish Lake Valley Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Fish Lake Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Density Log at Fish Lake Valley Area (DOE GTP) Exploration...

103

Wind: wind power density maps at 50m above ground and 1km resolution...  

Open Energy Info (EERE)

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

104

Wind: wind power density maps at 50 m above ground and 1km resolution...  

Open Energy Info (EERE)

maps ... Dataset Activity Stream Wind: wind power density maps at 50 m above ground and 1km resolution for Cuba from NREL (Abstract):HTMLREMOVEDHTMLREMOVEDRaster GIS data, 50...

105

Characteristics of the size distribution of recent and historical landslides in a populated hilly region  

Science Journals Connector (OSTI)

Despite the availability of studies on the frequency density of landslide areas in mountainous regions, frequencyarea distributions of historical landslide inventories in populated hilly regions are absent. This study revealed that the frequencyarea distribution derived from a detailed landslide inventory of the Flemish Ardennes (Belgium) is significantly different from distributions usually obtained in mountainous areas where landslides are triggered by large-scale natural causal factors such as rainfall, earthquakes or rapid snowmelt. Instead, the landslide inventory consists of the superposition of two populations, i.e. (i) small (1210?2km2), deep-seated landslides that are older than 100yr. Both subpopulations are best represented by a negative powerlaw relation with exponents of ?0.58 and ?2.31 respectively. This study focused on the negative powerlaw relation obtained for recent, small landslides, and contributes to the understanding of frequency distributions of landslide areas by presenting a conceptual model explaining this negative powerlaw relation for small landslides in populated hilly regions. According to the model hilly regions can be relatively stable under the present-day environmental conditions, and landslides are mainly triggered by human activities that have only a local impact on slope stability. Therefore, landslides caused by anthropogenic triggers are limited in size, and the number of landslides decreases with landslide area. The frequency density of landslide areas for old landslides is similar to those obtained for historical inventories compiled in mountainous areas, as apart from the negative powerlaw relation with exponent ?2.31 for large landslides, a positive powerlaw relation followed by a rollover is observed for smaller landslides. However, when analysing the old landslides together with the more recent ones, the present-day higher temporal frequency of small landslides compared to large landslides, obscures the positive powerlaw relation and rollover.

M. Van Den Eeckhaut; J. Poesen; G. Govers; G. Verstraeten; A. Demoulin

2007-01-01T23:59:59.000Z

106

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

E-Print Network (OSTI)

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

Kalnay, Eugenia

107

A nesting study of two populations of cardinals: urban and non-urban  

E-Print Network (OSTI)

) compaxed bird populations for one year in the center of a city, a rural area and an uninhabited forest in Finland. Bird biomass was found to be 10 times higher in the city than in either of the other two settings. Population density was found to be 342...

Kutac, Mary Florence

1976-01-01T23:59:59.000Z

108

ON THE TURTLE POPULATION S OF THE ISLANDS OFF THE EAST COAST OF JOHOR  

E-Print Network (OSTI)

A REPORT ON THE TURTLE POPULATION S OF THE ISLANDS OFF THE EAST COAST OF JOHOR AND SUGGESTIONS The Status of the Turtles of the Islands of Johor 1 Management Recommendations 1 SECTION 1 . INTRODUCTION The Resident Human Populations 3 SECTION 3 . SPECIES AND NESTING DENSITY OF THE TURTLES 3 3 .1 Hawksbill

Prestwich, Ken

109

The Ultimate-Sustainable-Yield Problem in Nonlinear Age-Structured Populations*  

E-Print Network (OSTI)

that it assumes that recruitment is independent of population density. *This work was partially supportedThe Ultimate-Sustainable-Yield Problem in Nonlinear Age-Structured Populations* WAYNE M. GETZ Africa Received 24 January 1979; revised IO Ju& 1979 ABSTRACT The Beverton-Holt theory of harvesting

Getz, Wayne M.

110

OIL EXPOSURE AND CHRONIC HEALTH EFFECTS ON INDIGENOUS POPULATIONS IN SOUTH AMERICA.  

E-Print Network (OSTI)

??There is an ongoing discussion on whether the activity of oil companies and its environmental impacts are a threat for the health of the populations (more)

Gascon Merlos, M.

2009-01-01T23:59:59.000Z

111

Density and pair-density scaling for deriving the Euler equation in density-functional and pair-density-functional theory  

SciTech Connect

A link between density and pair density functional theories is presented. Density and pair density scaling are used to derive the Euler equation in both theories. Density scaling provides a constructive way of obtaining approximations for the Pauli potential. The Pauli potential (energy) of the density functional theory is expressed as the difference of the scaled and original exchange-correlation potentials (energies).

Nagy, A. [Department of Theoretical Physics, University of Debrecen, H-4010 Debrecen (Hungary)

2011-09-15T23:59:59.000Z

112

Dynamical density functional theory for colloidal particles with arbitrary shape  

E-Print Network (OSTI)

Starting from the many-particle Smoluchowski equation, we derive dynamical density functional theory for Brownian particles with an arbitrary shape. Both passive and active (self-propelled) particles are considered. The resulting theory constitutes a microscopic framework to explore the collective dynamical behavior of biaxial particles in nonequilibrium. For spherical and uniaxial particles, earlier derived dynamical density functional theories are recovered as special cases. Our study is motivated by recent experimental progress in preparing colloidal particles with many different biaxial shapes.

Raphael Wittkowski; Hartmut Lwen

2011-06-12T23:59:59.000Z

113

The effects of plant density upon pollination success, reproductive effort and fruit parasitism in Cistus ladanifer L. (Cistaceae)  

E-Print Network (OSTI)

The effects of plant density upon pollination success, reproductive effort and fruit parasitism pollination success, reproductive effort and fruit parasitism in three populations of Cistus ladanifer L increased (pfruit parasitism showed the opposite pattern (both p

114

Abstract 1277: The association between seasonality, vitamin D and calcium intake and mammographic density in Norwegian postmenopausal women  

Science Journals Connector (OSTI)

...Health Economic and Drug Unit, Oslo, Norway, Norway. Background: Mammographic density (MD...obtained, as well as vitamin D intake, energy and calcium intake in a population of women from Norway, a country with limited sunlight exposure...

Merete Ellingjord-Dale; Isabel dos Santos Silva; Tom Grotmol; Amrit Kaur Sakhi; Samera Qureshi; Solveig Hofvind; Marianne Skov Markussen; Elisabeth Couto; Lene Frost Andersen; Giske Ursin; and Giske Ursin

2014-10-01T23:59:59.000Z

115

High energy density redox flow device  

DOE Patents (OSTI)

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.

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

2014-05-13T23:59:59.000Z

116

3-D Density Model Of Mt Etna Volcano (Southern Italy) | Open Energy  

Open Energy Info (EERE)

3-D Density Model Of Mt Etna Volcano (Southern Italy) 3-D Density Model Of Mt Etna Volcano (Southern Italy) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 3-D Density Model Of Mt Etna Volcano (Southern Italy) Details Activities (0) Areas (0) Regions (0) Abstract: A detailed density model of Mt. Etna and its surrounding areas has been evaluated using a 3-D inversion of the gravimetric data acquired in the 1980's. Several high-density and low-density bodies are found, penetrating from shallow depths as far down as 12 km bsl. A positive correlation (in terms of location, extent, density, and velocity) is established between several anomalies of the density model and features identified in previously published seismic tomographies. A prominent high-density body extending down to 7 km bsl is recognized in the southern

117

Near-Saturation Single-Photon Avalanche Diode Afterpulse and Sensitivity Correction Scheme for the LHC Longitudinal density Monitor  

E-Print Network (OSTI)

Single-Photon Avalanche Diodes (SPADs) monitor the longitudinal density of the LHC beams by measuring the temporal distribution of synchrotron radiation. The relative population of nominally empty RF-buckets (satellites or ghosts) with respect to filled bunches is a key figure for the luminosity calibration of the LHC experiments. Since afterpulsing from a main bunch avalanche can be as high as, or higher than, the signal from satellites or ghosts, an accurate correction algorithm is needed. Furthermore, to reduce the integration time, the amount of light sent to the SPAD is enough so that pile-up effects and afterpulsing cannot be neglected. The SPAD sensitivity has also been found to vary at the end of the active quenching phase. We present a method to characterize and correct for SPAD deadtime, afterpulsing and sensitivity variation near saturation, together with laboratory benchmarking.

Bravin, E; Palm, M

2014-01-01T23:59:59.000Z

118

USING CUMULATIVE NUMBER DENSITIES TO COMPARE GALAXIES ACROSS COSMIC TIME  

SciTech Connect

Comparing galaxies across redshifts at fixed cumulative number density is a popular way to estimate the evolution of specific galaxy populations. This method ignores scatter in mass accretion histories and galaxy-galaxy mergers, which can lead to errors when comparing galaxies over large redshift ranges (?z > 1). We use abundance matching in the ?CDM paradigm to estimate the median change in cumulative number density with redshift and provide a simple fit (+0.16 dex per unit ?z) for progenitors of z = 0 galaxies. We find that galaxy descendants do not evolve in the same way as galaxy progenitors, largely due to scatter in mass accretion histories. We also provide estimates for the 1? range of cumulative number densities corresponding to galaxy progenitors and descendants. Finally, we discuss some limits on cumulative number density comparisons, which arise due to difficulties measuring physical quantities (e.g., stellar mass) consistently across redshifts. A public tool to calculate cumulative number density evolution for galaxies, as well as approximate halo masses, is available online.

Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States)] [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)] [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)] [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Papovich, Casey [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)] [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)] [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)

2013-11-01T23:59:59.000Z

119

DENSITY LIMITS IN TOROIDAL PLASMAS MARTIN GREENWALD  

E-Print Network (OSTI)

(RFP) ---- Spheromaks and FRCs · Physics basis for density limit ---- Neutrals ---- Radiation models as fast terminations · Spheromak and FRC don't have density limit data operation at "optimized" density

Greenwald, Martin

120

Open problems in nuclear density functional theory  

E-Print Network (OSTI)

This note describes five subjects of some interest for the density functional theory in nuclear physics. These are, respectively, i) the need for concave functionals, ii) the nature of the Kohn-Sham potential for the radial density theory, iii) a proper implementation of a density functional for an "intrinsic" rotational density, iv) the possible existence of a potential driving the square root of the density, and v) the existence of many models where a density functional can be explicitly constructed.

B. G. Giraud

2009-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Space, Health and Population Economics  

E-Print Network (OSTI)

Space, Health SHaPE and Population Economics Changing Demographics and Immigration: Implications for IndianaImplications for Indiana Brigitte Waldorf, Purdue University Farm Policy Study Group b 20 07 December 2010 #12;Space, Health SHaPE and Population Economics America is ... ... Aging #12;Space, Health

122

POPULATION GEOGRAPHY Instructor: Dr. Carr  

E-Print Network (OSTI)

in a year · Crude rates may be misleading: - e.g., CDR, US (8) vs. Mexico (5) -What's going on here? -Are: #12;HOW DOES POPULATION CHANGE? #12;Population Change = Fertility ­ Mortality +/- Migration #12;Crude Birth Rate (CBR): Births/1000 individuals in a year Crude Death Rate (CDR): Deaths/1000 individuals

Lopez-Carr, David

123

vol. 155, no. 2 the american naturalist february 2000 Energy, Density, and Constraints to Species Richness: Ant  

E-Print Network (OSTI)

. This supports the energy limitation hypothesis' assumption that average population densities are highervol. 155, no. 2 the american naturalist february 2000 Energy, Density, and Constraints to Species in a given time and space. The energy limitation hy- pothesis links the species richness of consumer taxa

Kaspari, Mike

124

Nuclear energy density optimization: Shell structure  

Science Journals Connector (OSTI)

Background: 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.

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

2014-05-15T23:59:59.000Z

125

Energy demand and population changes  

SciTech Connect

Since World War II, US energy demand has grown more rapidly than population, so that per capita consumption of energy was about 60% higher in 1978 than in 1947. Population growth and the expansion of per capita real incomes have led to a greater use of energy. The aging of the US population is expected to increase per capita energy consumption, despite the increase in the proportion of persons over 65, who consume less energy than employed persons. The sharp decline in the population under 18 has led to an expansion in the relative proportion of population in the prime-labor-force age groups. Employed persons are heavy users of energy. The growth of the work force and GNP is largely attributable to the growing participation of females. Another important consequence of female employment is the growth in ownership of personal automobiles. A third factor pushing up labor-force growth is the steady influx of illegal aliens.

Allen, E.L.; Edmonds, J.A.

1980-12-01T23:59:59.000Z

126

Transformations for densities Linear transformations  

E-Print Network (OSTI)

' & $ % Lecture 28 Transformations for densities Linear transformations 1-1 differentiable functions General transformations Expectation of a function 1 #12;' & $ % Transformations for discrete transformation of a U[0, 1] · Take X U[0, 1], so that fX(x) = 1 0 0 and set Y

Adler, Robert J.

127

Definition: Density Log | Open Energy Information  

Open Energy Info (EERE)

Density Log Density Log Jump to: navigation, search Dictionary.png Density Log Density logging is a well logging tool that can provide a continuous record of a formation's bulk density along the length of a borehole. In geology, bulk density is a function of the density of the minerals forming a rock (i.e. matrix) and the fluid enclosed in the pore spaces.[1] View on Wikipedia Wikipedia Definition Density logging is a well logging tool that can provide a continuous record of a formation's bulk density along the length of a borehole. In geology, bulk density is a function of the density of the minerals forming a rock and the fluid enclosed in the pore spaces. This is one of three well logging tools that are commonly used to calculate porosity, the other two being sonic logging and neutron porosity logging

128

THE DENSITY PROFILES OF MASSIVE, RELAXED GALAXY CLUSTERS. II. SEPARATING LUMINOUS AND DARK MATTER IN CLUSTER CORES  

SciTech Connect

We present stellar and dark matter (DM) density profiles for a sample of seven massive, relaxed galaxy clusters derived from strong and weak gravitational lensing and resolved stellar kinematic observations within the centrally located brightest cluster galaxies (BCGs). In Paper I of the series, we demonstrated that the total density profile derived from these data, which span three decades in radius, is consistent with numerical DM-only simulations at radii {approx}> 5-10 kpc, despite the significant contribution of stellar material in the core. Here, we decompose the inner mass profiles of these clusters into stellar and dark components. Parameterizing the DM density profile as a power law {rho}{sub DM}{proportional_to}r {sup -{beta}} on small scales, we find a mean slope ({beta}) = 0.50 {+-} 0.10(random){sup +0.14} {sub -0.13}(systematic). Alternatively, cored Navarro-Frenk-White (NFW) profiles with (log r {sub core}/kpc) = 1.14 {+-} 0.13{sup +0.14} {sub -0.22} provide an equally good description. These density profiles are significantly shallower than canonical NFW models at radii {approx}< 30 kpc, comparable to the effective radii of the BCGs. The inner DM profile is correlated with the distribution of stars in the BCG, suggesting a connection between the inner halo and the assembly of stars in the central galaxy. The stellar mass-to-light ratio inferred from lensing and stellar dynamics is consistent with that inferred using stellar population synthesis models if a Salpeter initial mass function is adopted. We compare these results to theories describing the interaction between baryons and DM in cluster cores, including adiabatic contraction models and the possible effects of galaxy mergers and active galactic nucleus feedback, and evaluate possible signatures of alternative DM candidates.

Newman, Andrew B.; Ellis, Richard S. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States)] [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Treu, Tommaso; Sand, David J., E-mail: anewman@astro.caltech.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

2013-03-01T23:59:59.000Z

129

Energy density of variational states  

Science Journals Connector (OSTI)

We show, in several important and general cases, that a low variational energy density of a trial state is possible even when the trial state represents a different phase from the ground state. Specifically, we ask whether the ground-state energy density of a Hamiltonian whose ground state is in phase A can be approximated to arbitrary accuracy by a wave function, which represents a different phase B. We show this is indeed the case when A has discrete symmetry breaking order in one dimension or topological order in two dimensions, while B is disordered. We argue that, if reasonable conditions of physicality are imposed upon the trial wave function, then this is not possible when A has discrete symmetry breaking in dimensions greater than one and B is symmetric. Some other situations are also discussed.

Leon Balents

2014-12-08T23:59:59.000Z

130

Jacek Dobaczewski Density functional theory and energy  

E-Print Network (OSTI)

Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek Functional #12;Jacek Dobaczewski Mean-Field Theory Density Functional Theory · mean-field one? Density Functional Theory: A variational method that uses observables as variational parameters. #12;Jacek

Dobaczewski, Jacek

131

Parton Densities at the LHC  

E-Print Network (OSTI)

This contribution to the Italian "Workshop sui Monte Carlo, la Fisica e le Simulazioni a LHC", held at LNF, Frascati, in February, May and October 2006, summarises the status of parton density functions (PDF's) and the impact of their uncertainties on the LHC physics. Emphasis is given to methods of contraining PDF's using LHC data. Moreover, the advantages of the so-called PDF reweighting technique, which enables to quickly estimate PDF uncertainties with Monte Carlo events, are also presented.

A. Tricoli; for the ATLAS Collaboration

2008-08-19T23:59:59.000Z

132

Intraspecific variation in the strength of density dependence in aphid populations  

E-Print Network (OSTI)

varies both within and between studies (Strong, 1984; Bjornstad et al., 1995; Cappuccino & Price, 1995

Underwood, Nora

133

Estimating plant population density: Time costs and sampling efficiencies for different sized and shaped quadrats  

E-Print Network (OSTI)

and shaped quadrats Jennifer K. CARAH 1,3 (corresponding author) jkcarah@sfsu.edu 415-333-6092 home 415

Connor, Edward F.

134

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

E-Print Network (OSTI)

' s oestrus cycle by prostaglandins. J. Reprod, Fert. 33:539-543. Andrews, F. M. and F. F. McKenzie. 1941. Estrus, ovulation and related phenomena in the mare. Res. Bull. Univ. Mo. No. 329. Arthur, G. H. 1958. An analysis of the reproductive function... of mares based on post-mortem examination. Vet. Rec. 70:682-682. Arthur, G. H. 1968. The ovary of the mare in health and disease. Eq. Vet. J. 1:4:l. Arthur, G. H. 1975. Influence of intrauterine saline infusion upon the oestrous cycle of the mare. J...

Burke, Daniel John

2012-06-07T23:59:59.000Z

135

Snag density and composition of snag populations on two National Forests in northern Arizona  

E-Print Network (OSTI)

plots were located in ponderosa pine forest, with the remainder in mixed-conifer forest. Small snags in ponderosa pine and mixed-conifer forest, respectively, met or exceeded current U.S. Forest Service standards and mixed-conifer forest, respectively. This suggests that current standards for snag retention may

136

Population Densities of Rhizobium japonicum Strain 123 Estimated Directly in Soil and Rhizospheres  

Science Journals Connector (OSTI)

...of N per g of soil. Soil moisture was maintained...replicated four times. Loose soil not adhering to roots...rhizosphere sample. Root washings, as pre- viously described...from sterile Waukegon soil proved to be somewhat...treatment with Tween 80 surfactant and AF72 antifoam agent...

V. G. Reyes; E. L. Schmidt

1979-05-01T23:59:59.000Z

137

Relationships between body mass, population density, and the self-thinning  

E-Print Network (OSTI)

, increases in average body size may be accompanied by increases in per capita space and (or) energy, however, to identify causal mechanisms and eliminate alternative explanations for body size ­ abundance require more resources, the equilibrium number of individuals supported in a given environment (car- rying

138

Emergent multicellular life cycles in filamentous bacteria owing to density-dependent population dynamics  

Science Journals Connector (OSTI)

...filament lengths is reached. The corresponding pie-charts indicate the fraction of single...In figure-3 f, the box plots and the pie charts show the proportion of short and...capacity. As for the simulation results, the pie charts illustrate three length classes...

2011-01-01T23:59:59.000Z

139

The influence of increasing population size and vegetation productivity on elephant distribution in the Kruger National Park  

E-Print Network (OSTI)

-cell occupancy increased with population size, while grid-cell-specific density became less variable. In additionThe influence of increasing population size and vegetation productivity on elephant distribution Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa

Pretoria, University of

140

High density electronic circuit and process for making  

DOE Patents (OSTI)

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.

Morgan, William P. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Multiscale modeling of oscillations and spiral waves in Dictyostelium populations  

E-Print Network (OSTI)

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.

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

2014-09-12T23:59:59.000Z

142

Definition: Power density | Open Energy Information  

Open Energy Info (EERE)

density density Jump to: navigation, search Dictionary.png Power density The rate of energy flow (power) per unit volume, area or mass. Common metrics include: horsepower per cubic inch, watts per square meter and watts per kilogram.[1][2] View on Wikipedia Wikipedia Definition Power density (or volume power density or volume specific power) is the amount of power (time rate of energy transfer) per unit volume. In energy transformers like batteries, fuel cells, motors, etc. but also power supply units or similar, power density refers to a volume. It is then also called volume power density which is expressed as W/m. Volume power density is sometimes an important consideration where space is constrained. In reciprocated internal combustion engines, power density- power per swept

143

Density functional theory of electrowetting  

E-Print Network (OSTI)

The phenomenon of electrowetting, i.e., the dependence of the macroscopic contact angle of a fluid on the electrostatic potential of the substrate, is analyzed in terms of the density functional theory of wetting. It is shown that electrowetting is not an electrocapillarity effect, i.e., it cannot be consistently understood in terms of the variation of the substrate-fluid interfacial tension with the electrostatic substrate potential, but it is related to the depth of the effective interface potential. The key feature, which has been overlooked so far and which occurs naturally in the density functional approach is the structural change of a fluid if it is brought into contact with another fluid. These structural changes occur in the present context as the formation of finite films of one fluid phase in between the substrate and the bulk of the other fluid phase. The non-vanishing Donnan potentials (Galvani potential differences) across such film-bulk fluid interfaces, which generically occur due to an unequal partitioning of ions as a result of differences of solubility contrasts, lead to correction terms in the electrowetting equation, which become relevant for sufficiently small substrate potentials. Whereas the present density functional approach confirms the commonly used electrocapillarity-based electrowetting equation as a good approximation for the cases of metallic electrodes or electrodes coated with a hydrophobic dielectric in contact with an electrolyte solution and an ion-free oil, a significantly reduced tendency for electrowetting is predicted for electrodes coated with a dielectric which is hydrophilic or which is in contact with two immiscible electrolyte solutions.

Markus Bier; Ingrid Ibagon

2014-02-10T23:59:59.000Z

144

Density Log at Valles Caldera - Redondo Area (Wilt & Haar, 1986) | Open  

Open Energy Info (EERE)

Valles Caldera - Redondo Area (Wilt & Haar, 1986) Valles Caldera - Redondo Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Density at Valles Caldera - Redondo Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Density Log Activity Date Usefulness not indicated DOE-funding Unknown Notes The density log indicates three major density units within the well section : a surface layer of caldera fill, lake deposits, and other recent alluvium (2.12 g/cm3); the Bandelier Tuff and underlying volcanic and sedimentary units (2.3--2.5 g/cm3); and the basement unit, consisting of the lower Paleozoic and the upper Precambrian (2.65 g/cm3). There are, of course, significant density variations within each unit, but for modeling

145

Estimation of Density of Biodiesel  

Science Journals Connector (OSTI)

In addition, the numeric value for coefficient e is very small (?0.00001) and the nd(ave) of most biodiesels are not greater than 2. Therefore, the product of e nd(ave) can be neglected without affecting the accuracy of the calculation and eq 30 is good for estimation of density of biodiesel. ... Interestingly, the %AAD for mixed biodiesel (0.38) is lower than those of pure (0.41%) and total biodiesels. ... (21) The model cannot differentiate a mixed biodiesel from pure biodiesels. ...

Suriya Phankosol; Kaokanya Sudaprasert; Supathra Lilitchan; Kornkanok Aryusuk; Kanit Krisnangkura

2014-06-16T23:59:59.000Z

146

Proceedings: Workshop on Compensatory Mechanisms in Fish Populations  

SciTech Connect

This report contains a summary of an EPRI workshop on compensatory mechanisms in fish populations, held in February 1982 in Palo Alto, California. The participants recommended two broad conceptual frameworks for the development of a research program and identified major research activities. These plans were later integrated into a final research program, which is included here.

None

1982-12-01T23:59:59.000Z

147

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1  

E-Print Network (OSTI)

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1 , Julien and CNRS, 4 place Jussieu, 75252 Paris, France We combine density-functional theory with density cleavage is an ubiquitous process for chemistry. Density-matrix functional theory (DMFT) (see, e.g., Refs

Paris-Sud XI, Université de

148

Energy-Density Enhancement of Carbon-Nanotube-Based Supercapacitors with Redox Couple in Organic Electrolyte  

Science Journals Connector (OSTI)

Energy-Density Enhancement of Carbon-Nanotube-Based Supercapacitors with Redox Couple in Organic Electrolyte ... The redox molecule also contributes to increasing the cell capacitance by a faradaic redox reaction, and therefore the energy density of the supercapacitor can be significantly increased. ... More specifically, the addition of redox-active decamethylferrocene in an organic electrolyte results in an approximately 27-fold increase in the energy density of carbon-nanotube-based supercapacitors. ...

Jinwoo Park; Byungwoo Kim; Young-Eun Yoo; Haegeun Chung; Woong Kim

2014-11-16T23:59:59.000Z

149

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Details Activities (1) Areas (1) Regions (0) Abstract: This project aims to improve understanding of the subsurface fracture system in the Coso geothermal field, located in the east central California. We applied shear-wave splitting technique on a set of high quality, locally recorded microearthquake (MEQ) data. Four major fracture directions have been identified from the seismograms recorded by the permanent sixteen-station down-hole array: N10- 20W, NS, N20E, and N40-45E,

150

Unbiased Reduced Density Matrices and Electronic Properties from Full Configuration Interaction Quantum Monte Carlo  

E-Print Network (OSTI)

Properties that are necessarily formulated within pure (symmetric) expectation values are difficult to calculate for projector quantum Monte Carlo approaches, but are critical in order to compute many of the important observable properties of electronic systems. Here, we investigate an approach for the sampling of unbiased reduced density matrices within the Full Configuration Interaction Quantum Monte Carlo dynamic, which requires only small computational overheads. This is achieved via an independent replica population of walkers in the dynamic, sampled alongside the original population. The resulting reduced density matrices are free from systematic error (beyond those present via constraints on the dynamic itself), and can be used to compute a variety of expectation values and properties, with rapid convergence to an exact limit. A quasi-variational energy estimate derived from these density matrices is proposed as an accurate alternative to the projected estimator for multiconfigurational wavefunctions, ...

Overy, Catherine; Blunt, N S; Shepherd, James; Cleland, Deidre; Alavi, Ali

2014-01-01T23:59:59.000Z

151

Scalar Nature of the Nuclear Density Functional  

E-Print Network (OSTI)

Because of the rotational invariance of the nuclear Hamiltonian, there exists a density functional for nuclei that depends only on two scalar densities. Practical calculations boil down to radial, one-dimensional ones.

B. G. Giraud

2008-01-22T23:59:59.000Z

152

Risk Bounds for Mixture Density Estimation  

E-Print Network (OSTI)

In this paper we focus on the problem of estimating a bounded density using a finite combination of densities from a given class. We consider the Maximum Likelihood Procedure (MLE) and the greedy procedure described by ...

Rakhlin, Alexander

2004-01-27T23:59:59.000Z

153

Biodiesel Density: Experimental Measurements and Prediction Models  

Science Journals Connector (OSTI)

Density is an important biodiesel parameter, with impact on fuel quality. Predicting density is of high relevance for a correct formulation of an adequate blend of raw materials that optimize the cost of biodiesel fuel production while allowing the ...

Maria Jorge Pratas; Samuel V. D. Freitas; Mariana B. Oliveira; Slvia C. Monteiro; lvaro S. Lima; Joo A. P. Coutinho

2011-04-19T23:59:59.000Z

154

The dynamics of variable-density turbulence  

SciTech Connect

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field, is in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations. In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For the case of buoyancy-generated turbulence, variable-density departures from the Boussinesq approximation are studied. The results of the buoyancy-generated turbulence are compared with variable-density model predictions. Both a one-point (engineering) model and a two-point (spectral) model are tested against the numerical data. Some deficiencies in these variable-density models are discussed and modifications are suggested.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

155

Quantum critical benchmark for density functional theory  

E-Print Network (OSTI)

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.

Paul E. Grabowski; Kieron Burke

2014-08-09T23:59:59.000Z

156

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

E-Print Network (OSTI)

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

Shirley, Yancy L

2015-01-01T23:59:59.000Z

157

Time Dependent Density Functional Theory An introduction  

E-Print Network (OSTI)

Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 1 / 62 #12;Outline 1 Introduction: why and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 2 / 62

Botti, Silvana

158

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS  

E-Print Network (OSTI)

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS E. Engel Inst. fur Theor. Physik background of relativistic density functional theory is emphasized and its consequences for relativistic Kohn-Sham equations are shown. The local density approximation for the exchange energy functional is reviewed

Engel, Eberhard

159

Density functional theory George F. Bertsch  

E-Print Network (OSTI)

Density functional theory George F. Bertsch #3; Institute for Nuclear Theory and Department of Physics University of Tsukuba Tsukuba 305-8577 Japan Abstract Density functional theory is a remarkably Time-dependent density functional theory: the equations 34 A Optical properties

Bertsch George F.

160

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF  

E-Print Network (OSTI)

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF ELECTRON CORRELATIONS E.K.U. Gross and Stefan The basic idea of density functional theory is to describe a many-electron system exclusively and completely-consistent scheme, known as the Kohn-Sham scheme [2], is the heart of modern density functional theory

Gross, E.K.U.

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

E-Print Network (OSTI)

. 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...

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

2009-08-11T23:59:59.000Z

162

Thermodynamics of urban population flows  

Science Journals Connector (OSTI)

Orderliness, reflected via mathematical laws, is encountered in different frameworks involving social groups. Here we show that a thermodynamics can be constructed that macroscopically describes urban population flows. Microscopic dynamic equations and simulations with random walkers underlie the macroscopic approach. Our results might be regarded, via suitable analogies, as a step towards building an explicit social thermodynamics.

A. Hernando and A. Plastino

2012-12-05T23:59:59.000Z

163

Shrinking Global Population: A futuristic scenario  

E-Print Network (OSTI)

global population it will not be a game-changer. #12;Measures for changes in total births 1. TotalShrinking Global Population: A futuristic scenario or a current challenge. Hillel Bar of RSAI - Atlanta November 15, 2013 #12;The evolution of global population Year Global Population

Nagurney, Anna

164

Population Ecology ISSN 1438-3896  

E-Print Network (OSTI)

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

de Aguiar, Marcus A. M.

165

From echolocation clicks to animal densityAcoustic sampling of harbor porpoises with static dataloggers  

Science Journals Connector (OSTI)

Monitoring abundance and population trends of small odontocetes is notoriously difficult and labor intensive. There is a need to develop alternative methods to the traditional visual line transect surveys especially for low density areas. Here the prospect of obtaining robust density estimates for porpoises by passive acoustic monitoring (PAM) is demonstrated by combining rigorous application of methods adapted from distance sampling to PAM. Acoustic dataloggers (T-PODs) were deployed in an area where harbor porpoises concurrently were tracked visually. Probability of detection was estimated in a markrecapture approach where a visual sighting constituted a mark and a simultaneous acoustic detection a recapture. As a distance could be assigned to each visual observation a detection function was estimated. Effective detection radius of T-PODs ranged from 22 to 104 m depending on T-POD type T-POD sensitivity train classification settings and snapshot duration. The T-POD density estimates corresponded to the visual densities derived concurrently for the same period. With more dataloggers located according to a systematic design density estimates would be obtainable for a larger area. This provides a method suitable for monitoring in areas with densities too low for visual surveys to be practically feasible e.g. the endangered harbor porpoise population in the Baltic.

Line A. Kyhn; Jakob Tougaard; Len Thomas; Linda Rosager Duve; Joanna Stenback; Mats Amundin; Genevive Desportes; Jonas Teilmann

2012-01-01T23:59:59.000Z

166

The dynamics of variable-density turbulence  

SciTech Connect

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field is, in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations (such that the Boussinesq approximation is not valid). In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For this case, the pdf of the density becomes asymmetric about its mean value during the early stages of its evolution. It is argued that these asymmetries in the pdf of the density field are due to different entrainment rates, into the mixing region, that favor the high speed fluid.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

167

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect

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.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

168

Phase switching in population cycles  

Science Journals Connector (OSTI)

...f (xt))X This is the expression we would use to calculate the popu- lation density at every second time-step. If we rede ne a unit of time to be two of the original units of time, we have the composite Ricker map xt +1 f(f(xt)): xt 1 bbxte...

1998-01-01T23:59:59.000Z

169

A Unifying Theory for Scaling Laws of Human Populations  

E-Print Network (OSTI)

The spatial distribution of people exhibits clustering across a wide range of scales, from household (~$10^{-2}$ km) to continental (~$10^4$ km) scales. Empirical data indicates simple power-law scalings for the size distribution of cities (known as Zipf's law), the geographic distribution of friends, and the population density fluctuations as a function of scale. We derive a simple statistical model that explains all of these scaling laws based on a single unifying principle involving the random spatial growth of clusters of people on all scales. The model makes important new predictions for the spread of diseases and other social phenomena.

Lin, Henry W

2015-01-01T23:59:59.000Z

170

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete phenomena  

E-Print Network (OSTI)

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete for representing geographic patterns. Dot density maps are particularly useful for understanding global distribution of the mapped phenomenon and comparing relative densities of different regions on the map. Dot

Klippel, Alexander

171

KH Computational Physics-2009 Density Functional Theory (DFT) Density Functional Theory  

E-Print Network (OSTI)

KH Computational Physics- 2009 Density Functional Theory (DFT) Density Functional Theory of interacting particles. Kristjan Haule, 2009 ­2­ #12;KH Computational Physics- 2009 Density Functional Theory functional of n. Kristjan Haule, 2009 ­3­ #12;KH Computational Physics- 2009 Density Functional Theory (DFT

Haule, Kristjan

172

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density approximation  

E-Print Network (OSTI)

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density the approximationstreat long-rangeand short-rangepotentials. I. INTRODUCTION The density-functional theory of nonuniform of density- functional theory to the problem of freezing of classical liquids,4 and in particular

Likos, Christos N.

173

Distribution of a Population of Rhizobium leguminosarum bv. trifolii among Different Size Classes of Soil Aggregates  

Science Journals Connector (OSTI)

...from 5 to 77 times greater than the populations...corresponding aggregate size classes of the fallow and...to 2.0-mm size class of the legume treatment...contained a significantly greater density of AR18 than the size classes of 0.25, 0.25...

Ieda C. Mendes; Peter J. Bottomley

1998-03-01T23:59:59.000Z

174

Theoretical Population Biology 53, 216 235 (1998) Evolutionary Stable Strategies and Trade-Offs  

E-Print Network (OSTI)

Theoretical Population Biology 53, 216 235 (1998) Evolutionary Stable Strategies and Trade Mathematics, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South Africa and Wayne M in which a parameter # characterizes the onset of density dependence. An evolutionary stable strategy

Getz, Wayne M.

175

Theoretical Population Biology 71 (2007) 111 Nonlinear dynamics and pattern bifurcations in a model for vegetation  

E-Print Network (OSTI)

Theoretical Population Biology 71 (2007) 1­11 Nonlinear dynamics and pattern bifurcations observed in aerial photographs of sub- Saharan Africa in the 1950s (MacFadyen, 1950; Hemming, 1965; Wickens in the plant density U because the presence of plant roots in the soil increases water ARTICLE IN PRESS www

Sherratt, Jonathan A.

176

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

SciTech Connect

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}.

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

177

Mon. Not. R. Astron. Soc. 000, ???? (2012) Printed 3 May 2013 (MN LATEX style file v2.2) Herschel -ATLAS/GAMA: The Environmental Density of  

E-Print Network (OSTI)

the normalized environmental densities of these two populations. This is such that infrared emission (a tracer -ATLAS/GAMA: The Environmental Density of Far-Infrared Bright Galaxies at z 0.5 C. S. Burton1 , Matt J1 3RH, UK 3Physics Department, University of the Western Cape, Bellville 7535, South Africa 4School

Baes, Maarten

178

Density Log at Alum Area (Moos & Ronne, 2010) | Open Energy Information  

Open Energy Info (EERE)

Moos & Ronne, 2010) Moos & Ronne, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Density Log at Alum Geothermal Area (Moos & Ronne, 2010) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Density Log Activity Date Usefulness useful DOE-funding Unknown Notes Density, photo-electric factor (PEF), neutron, and gamma ray (GR) logs provided sufficient information to clearly delineate basement lithologic variations, suggesting that pulsed neutron logs may not in many cases be needed, and density and electrical resistivity data were important to calibrate structural models based on surface surveys. References Daniel Moos, Joel Ronne (2010) Selecting The Optimal Logging Suite For Geothermal Reservoir Evaluation- Results From The Alum 25-29 Well,

179

Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation  

SciTech Connect

California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.

Carlsen, T M; Paterson, L E; Alfaro, T M

2009-07-15T23:59:59.000Z

180

Quartz resonator fluid density and viscosity monitor  

DOE Patents (OSTI)

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.

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

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Buoyancy-generated variable-density turbulence  

SciTech Connect

Both a one-point (engineering) and a two-point (spectral) model are tested against numerical data. Deficiencies in these variable-density models are disucssed and modifications are suggested. Attention is restricted to turbulent interactions of two miscible, incompressible Newtonian fluids of different densities. Departures from the limits of validity of the Boussinesq approximation are examined. Results of the buoyancy-generated turbulence are compared with variable-density model predictions. 3 figs, 6 refs.

Sandoval, D.L. [Los Alamos National Lab., NM (United States)]|[Washington Univ. (United States); Clark, T.T. [Los Alamos National Lab., NM (United States); Riley, J.J. [Washington Univ. (United States)

1996-06-01T23:59:59.000Z

182

Considering Air Density in Wind Power Production  

E-Print Network (OSTI)

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.

Farkas, Zn

2011-01-01T23:59:59.000Z

183

Considering Air Density in Wind Power Production  

E-Print Network (OSTI)

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.

Zn Farkas

2011-03-11T23:59:59.000Z

184

Dark Matter Density in Disk Galaxies  

E-Print Network (OSTI)

I show that the predicted densities of the inner dark matter halos in LCDM models of structure formation appear to be higher than estimates from real galaxies and constraints from dynamical friction on bars. This inconsistency would not be a problem for the LCDM model if physical processes that are omitted in the collisionless collapse simulations were able to reduce the dark matter density in the inner halos. I review the mechanisms proposed to achieve the needed density reduction.

J. A. Sellwood

2008-07-12T23:59:59.000Z

185

Dworshak Reservoir Kokanee Population Monitoring, Annual Report 2001.  

SciTech Connect

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.

Maiolie, Melo; Stark, Eric

2003-03-01T23:59:59.000Z

186

The 2dF Galaxy Redshift Survey: luminosity functions by density environment and galaxy type  

E-Print Network (OSTI)

We use the 2dF Galaxy Redshift Survey to measure the dependence of the bJ-band galaxy luminosity function on large-scale environment, defined by density contrast in spheres of radius 8h-1Mpc, and on spectral type, determined from principal component analysis. We find that the galaxy populations at both extremes of density differ significantly from that at the mean density. The population in voids is dominated by late types and shows, relative to the mean, a deficit of galaxies that becomes increasingly pronounced at magnitudes brighter than M_bJ-5log10h <-18.5. In contrast, cluster regions have a relative excess of very bright early-type galaxies with M_bJ-5log10h < -21. Differences in the mid to faint-end population between environments are significant: at M_bJ-5log10h=-18 early and late-type cluster galaxies show comparable abundances, whereas in voids the late types dominate by almost an order of magnitude. We find that the luminosity functions measured in all density environments, from voids to clusters, can be approximated by Schechter functions with parameters that vary smoothly with local density, but in a fashion which differs strikingly for early and late-type galaxies. These observed variations, combined with our finding that the faint-end slope of the overall luminosity function depends at most weakly on density environment, may prove to be a significant challenge for models of galaxy formation.

Darren J. Croton; Glennys R. Farrar; Peder Norberg; Matthew Colless; John A. Peacock; I. K. Baldry; C. M. Baugh; J. Bland-Hawthorn; T. Bridges; R. Cannon; S. Cole; C. Collins; W. Couch; G. Dalton; R. De Propris; S. P. Driver; G. Efstathiou; R. S. Ellis; C. S. Frenk; K. Glazebrook; C. Jackson; O. Lahav; I. Lewis; S. Lumsden; S. Maddox; D. Madgwick; B. A. Peterson; W. Sutherland; K. Taylor

2005-02-08T23:59:59.000Z

187

Density Measurements of Argonne Premium Coal Samples  

Science Journals Connector (OSTI)

Density Measurements of Argonne Premium Coal Samples ... Constitution of Illinois No. 6 Argonne Premium Coal: A Review ... Constitution of Illinois No. 6 Argonne Premium Coal: A Review ...

He Huang; Keyu Wang; David M. Bodily; V. J. Hucka

1995-01-01T23:59:59.000Z

188

Some challenges for Nuclear Density Functional Theory  

E-Print Network (OSTI)

We discuss some of the challenges that the DFT community faces in its quest for the truly universal energy density functional applicable over the entire nuclear chart.

T. Duguet; K. Bennaceur; T. Lesinski; J. Meyer

2006-06-20T23:59:59.000Z

189

3-D capacitance density imaging system  

DOE Patents (OSTI)

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.

Fasching, G.E.

1988-03-18T23:59:59.000Z

190

High Energy Density Ultracapacitors | Department of Energy  

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

Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation es038smith2011p.pdf More Documents & Publications High Energy Density Ultracapacitors High...

191

Individual-based model of yellow perch and walleye populations in Oneida Lake  

SciTech Connect

Predator-prey dynamics and density dependence are fundamental issues in ecology. The authors use a detailed, individual-based model of walleye and yellow perch to investigate the effects of alternative prey and compensatory responses on predator and prey population dynamics. The analyses focus on the numerical and developmental responses of the predator, rather than the traditional emphasis on functional responses. The extensive database for Oneida Lake, New York, USA was used to configure the model and ensure its realism. The model follows the daily growth, mortality, and spawning of individuals of each species through their lifetime. Three ecologically distinct periods in the history of Oneida Lake were simulated: baseline, high mayfly densities, and high forage fish densities. Mayflies and forage fish act as alternative prey for walleye. For model corroboration, the three periods were simulated sequentially as they occurred in Oneida Lake. Model predictions of abundances, size at age, and growth and survival rates compared favorably with Oneida Lake data. Three hypotheses suggested by the data were evaluated: alternative prey stabilizes yellow perch and walleye populations; alternative prey increases yellow perch and walleye recruitment; and density-dependent growth and survival compensate for changes in young-of-the-year mortality. Model simulations were performed under increased mayfly densities, increased forage fish densities, and increased egg mortality rates.

Rose, K.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Rutherford, E.S. [Univ. of Michigan, Ann Arbor, MI (United States). Inst. for Fisheries Research; McDermot, D.S. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Ecology and Evolutionary Biology; Forney, J.L.; Mills, E.L. [Cornell Univ. Biological Station, Bridgeport, NY (United States)

1999-05-01T23:59:59.000Z

192

INVESTIGATION Inferring Admixture Histories of Human Populations  

E-Print Network (OSTI)

and apply to test for admixture among all populations from the Human Genome Diversity Project (HGDPINVESTIGATION Inferring Admixture Histories of Human Populations Using Linkage Disequilibrium Po-range migrations and the resulting admixtures between populations have been important forces shaping human genetic

Reich, David

193

Microinstabilities in weak density gradient tokamak systems  

SciTech Connect

A prominent characteristic of auxiliary-heated tokamak discharges which exhibit improved (''H-mode type'') confinement properties is that their density profiles tend to be much flatter over most of the plasma radius. Depsite this favorable trend, it is emphasized here that, even in the limit of zero density gradient, low-frequency microinstabilities can persist due to the nonzero temperature gradient.

Tang, W.M.; Rewoldt, G.; Chen, L.

1986-04-01T23:59:59.000Z

194

Density Estimation Trees in High Energy Physics  

E-Print Network (OSTI)

Density Estimation Trees can play an important role in exploratory data analysis for multidimensional, multi-modal data models of large samples. I briefly discuss the algorithm, a self-optimization technique based on kernel density estimation, and some applications in High Energy Physics.

Anderlini, Lucio

2015-01-01T23:59:59.000Z

195

How to Calculate Molecular Column Density  

E-Print Network (OSTI)

The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is con...

Mangum, Jeffrey G

2015-01-01T23:59:59.000Z

196

Density functional theory for carbon dioxide crystal  

SciTech Connect

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.

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

197

Density of Spray-Formed Materials  

SciTech Connect

Spray Forming is an advanced materials processing technology that transforms molten metal into a near-net-shape solid by depositing atomized droplets onto a substrate. Depending on the application, the spray-formed material may be used in the as-deposited condition or it may undergo post-deposition processing. Regardless, the density of the as-deposited material is an important issue. Porosity is detrimental because it can significantly reduce strength, toughness, hardness and other properties. While it is not feasible to achieve fully-dense material in the as-deposited state, density greater than 99% of theoretical density is possible if the atomization and impact conditions are optimized. Thermal conditions at the deposit surface and droplet impact angle are key processing parameters that influence the density of the material. This paper examines the factors that contribute to porosity formation during spray forming and illustrates that very high as-deposited density is achieved by optimizing processing parameters.

Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

2008-06-01T23:59:59.000Z

198

Neutral depletion and the helicon density limit  

SciTech Connect

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.

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

199

Ions in solution: Density corrected density functional theory (DC-DFT)  

SciTech Connect

Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HOCl{sup ?} and HOH{sub 2}O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.

Kim, Min-Cheol; Sim, Eunji, E-mail: esim@yonsei.ac.kr [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of)] [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Burke, Kieron [Department of Chemistry, University of California, Irvine, California 92697 (United States)] [Department of Chemistry, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

200

Galaxy ecology: groups and low-density environments in the SDSS and 2dFGRS  

E-Print Network (OSTI)

We analyse the observed correlation between galaxy environment and H-alpha emission line strength, using volume-limited samples and group catalogues of 24968 galaxies drawn from the 2dF Galaxy Redshift Survey (Mb<-19.5) and the Sloan Digital Sky Survey (Mr<-20.6). We characterise the environment by 1) Sigma_5, the surface number density of galaxies determined by the projected distance to the 5th nearest neighbour; and 2) rho1.1 and rho5.5, three-dimensional density estimates obtained by convolving the galaxy distribution with Gaussian kernels of dispersion 1.1 Mpc and 5.5 Mpc, respectively. We find that star-forming and quiescent galaxies form two distinct populations, as characterised by their H-alpha equivalent width, EW(Ha). The relative numbers of star-forming and quiescent galaxies varies strongly and continuously with local density. However, the distribution of EW(Ha) amongst the star-forming population is independent of environment. The fraction of star-forming galaxies shows strong sensitivity to the density on large scales, rho5.5, which is likely independent of the trend with local density, rho1.1. We use two differently-selected group catalogues to demonstrate that the correlation with galaxy density is approximately independent of group velocity dispersion, for sigma=200-1000 km/s. Even in the lowest density environments, no more than ~70 per cent of galaxies show significant H-alpha emission. Based on these results, we conclude that the present-day correlation between star formation rate and environment is a result of short-timescale mechanisms that take place preferentially at high redshift, such as starbursts induced by galaxy-galaxy interactions.

Michael Balogh; Vince Eke; Chris Miller; Ian Lewis; Richard Bower; Warrick Couch; Robert Nichol; Joss Bland-Hawthorn; Ivan K. Baldry; Carlton Baugh; Terry Bridges; Russell Cannon; Shaun Cole; Matthew Colless; Chris Collins; Nicholas Cross; Gavin Dalton; Roberto De Propris; Simon P. Driver; George Efstathiou; Richard S. Ellis; Carlos S. Frenk; Karl Glazebrook; Percy Gomez; Alex Gray; Edward Hawkins; Carole Jackson; Ofer Lahav; Stuart Lumsden; Steve Maddox; Darren Madgwick; Peder Norberg; John A. Peacock; Will Percival; Bruce A. Peterson; Will Sutherland; Keith Taylor

2004-01-05T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

The Active Asteroids  

E-Print Network (OSTI)

Some asteroids eject dust, producing transient, comet-like comae and tails; these are the active asteroids. The causes of activity in this newly-identified population are many and varied. They include impact ejection and disruption, rotational instabilities, electrostatic repulsion, radiation pressure sweeping, dehydration stresses and thermal fracture, in addition to the sublimation of asteroidal ice. These processes were either unsuspected or thought to lie beyond the realm of observation before the discovery of asteroid activity. Scientific interest in the active asteroids lies in their promise to open new avenues into the direct study of asteroid destruction, the production of interplanetary debris, the abundance of asteroid ice and the origin of terrestrial planet volatiles.

Jewitt, David; Agarwal, Jessica

2015-01-01T23:59:59.000Z

202

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

E-Print Network (OSTI)

-facies metamorphic rocks. Velocity-density data was compiled from the literature for pressures greater than 600 MPa and linear fits of density on slowness were made. No correction was made for the effect of temperature. Densities were then estimated for a number...

Jones, Gary Wayne

2012-06-07T23:59:59.000Z

203

Testing the kinetic energy functional: Kinetic energy density as a density functional  

E-Print Network (OSTI)

is to the exchange-correlation energy as a functional of the density. A large part of the total energy, the kinetic contexts. For finite systems these forms integrate to the same global ki- netic energy, but they differTesting the kinetic energy functional: Kinetic energy density as a density functional Eunji Sim

Burke, Kieron

204

Density equalizing map projections (cartograms) in public health applications  

SciTech Connect

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.

Merrill, D.W.

1998-05-01T23:59:59.000Z

205

Cosmological Deuterium Abundance and the Baryon Density of the Universe  

E-Print Network (OSTI)

Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been interpreted as confirmation of the model (Copi, Schramm & Turner 1995). Here we present a measurement of the deuterium to hydrogen ratio (D/H) in a newly discovered high redshift metal-poor gas cloud at redshift $z=2.504$. This confirms our earlier measurement of D/H (Tytler, Fan & Burles 1996), and together they give the first accurate measurement of the primordial D abundance, and a ten fold improvement in the accuracy of the cosmological density of ordinary matter.This is a high density, with most ordinary matter unaccounted or dark, which is too high to agree with measurements of the primordial abundances of helium-4 and lithium-7. Since the D/H measurement is apparently simple, direct, accurate and highly sensitive, we propose that helium requires a systematic correction, and that population II stars have less than the primordial abundance of $^7$Li. Alternatively, there is no concordance between the light element abundances, and the simple model of the big bang must be incomplete and lacking physics, or wrong.

Scott Burles; David Tytler

1996-03-19T23:59:59.000Z

206

The Biermann Battery In Cosmological Mhd Simulations Of Population III Star Formation  

SciTech Connect

We report the results of the first self-consistent three-dimensional adaptive mesh refinement magnetohydrodynamical simulations of Population III star formation including the Biermann battery effect. We find that the Population III stellar cores formed including this effect are both qualitatively and quantitatively similar to those from hydrodynamics-only (non-MHD) cosmological simulations. We observe peak magnetic fields of {approx_equal} 10{sup -9} G in the center of our star-forming halo at z {approx_equal} 17.55 at a baryon density of n{sub B} {approx} 10{sup 10} cm{sup -3}. The magnetic fields created by the Biermann battery effect are predominantly formed early in the evolution of the primordial halo at low density and large spatial scales, and then grow through compression and by shear flows. The fields seen in this calculation are never large enough to be dynamically important (with {beta} {ge} 10{sup 15} at all times before the termination of our calculation), and should be considered the minimum possible fields in existence during Population III star formation. The lack of magnetic support lends credibility to assumptions made in previous calculations regarding the lack of importance of magnetic fields in Population III star formation. In addition, these magnetic fields may be seed fields for the stellar dynamo or the magnetorotational instability at higher densities and smaller spatial scales.

Xu, Hao [Los Alamos National Laboratory; O' Shea, Brian W [Los Alamos National Laboratory; Li, Hui [Los Alamos National Laboratory; Li, Shengtai [Los Alamos National Laboratory; Norman, Michael L [UCSD; Collins, David C [UCSD

2008-01-01T23:59:59.000Z

207

Calculations of population transfer during intense laser pulses  

SciTech Connect

Recent experiments by several groups have examined the question of population transfer to resonantly excited states during intense short laser pulses, in particular the amount of population that remains ``trapped`` in excited states at the end of a laser pulse. In this chapter we present calculations of population transfer and resonant ionization in xenon at both 660 and 620 nm. At the longer wavelength, the seven photon channel closes at 2.5{times}10{sup 13} W/cm{sup 2}. Pulses with peak intensities higher than this result in ``Rydberg trapping``, the resonant transfer of population to a broad range of high-lying states. The amount of population transferred depends on both the peak intensity and pulse duration. At 620 mm there are numerous possible six photon resonances to states with p or f angular momentum. We have done a large number of calculations for 40 fs pulses at different peak intensities and have examined the population transferred to these low-lying resonant states as a function of the peak laser intensity. We do not have room to comment upon the resonantly enhanced ionized electron energy spectra that we also determine in the same calculations. Our calculations involve the direct numerical integration of the time-dependent Schroedinger equation for an atom interacting with a strong laser field. The time-dependent wave function of a given valence electron is calculated on a spatial grid using a one-electron pseudo potential. This single active electron approximation (SAE) has been shown to be a good approximation for the rare gases at the intensities and wavelengths that we will consider. The SAE potential we use has an explicit angular momentum dependence which allows us to reproduce all of the excited state energies for xenon quite well.

Schafer, K.J.; Kulander, K.C.

1993-08-01T23:59:59.000Z

208

Density Prediction of Uranium-6 Niobium Ingots  

SciTech Connect

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.

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

2003-04-15T23:59:59.000Z

209

PROJECTED CENTRAL DARK MATTER FRACTIONS AND DENSITIES IN MASSIVE EARLY-TYPE GALAXIES FROM THE SLOAN DIGITAL SKY SURVEY  

SciTech Connect

We investigate in massive early-type galaxies the variation of their two-dimensional central fraction of dark over total mass and dark matter density as a function of stellar mass, central stellar velocity dispersion, effective radius, and central surface stellar mass density. We use a sample of approximately 1.7 x 10{sup 5} galaxies from the Sloan Digital Sky Survey Data Release Seven (SDSS DR7) at redshift smaller than 0.33. We apply conservative photometric and spectroscopic cuts on the SDSS DR7 and the MPA/JHU value-added galaxy catalogs, to select galaxies with physical properties similar to those of the lenses studied in the Sloan Lens ACS Survey. The values of the galaxy stellar and total mass projected inside a cylinder of radius equal to the effective radius are obtained, respectively, by fitting the SDSS multicolor photometry with stellar population synthesis models, under the assumption of a Chabrier stellar initial mass function (IMF), and adopting a one-component isothermal total mass model with effective velocity dispersion approximated by the central stellar velocity dispersion. The plausibility of an isothermal model to represent the galaxy total mass distribution is supported by independent gravitational lensing and stellar-dynamical analyses performed in the lens subsample, which is found here to represent nicely the entire galaxy sample. We find that within the effective radius the stellar mass estimates differ from the total ones by only a relatively constant proportionality factor. In detail, we observe that the values of the projected fraction of dark over total mass and the logarithmic values of the central surface dark matter density (measured in M{sub sun} kpc{sup -2}) have almost Gaussian probability distribution functions, with median values of 0.64{sup +0.08}{sub -0.11} and 9.1{sup +0.2}{sub -0.2}, respectively. We discuss the observed correlations between these quantities and other galaxy global parameters and show that our results disfavor an interpretation of the tilt of the fundamental plane in terms of differences in the galaxy dark matter content and give useful information on the possible variations of the galaxy stellar IMF and dark matter density profile. Finally, we provide some observational evidence on the likely significant contribution of dry minor mergers, feedback from active galactic nuclei, and/or coalescence of binary black holes on the formation and evolution of massive early-type galaxies.

Grillo, C., E-mail: cgrillo@eso.or [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstr. 2, D-85748, Garching (Germany); Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstr., D-85748, Garching (Germany); Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany)

2010-10-10T23:59:59.000Z

210

A Comprehensive Study Of Fracture Patterns And Densities In The Geysers  

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: A Comprehensive Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Details Activities (1) Areas (1) Regions (0) Abstract: In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be

211

Application of high?resolution interferometry to plasma density measurements on TEXT?Upgrade  

Science Journals Connector (OSTI)

High?resolution interferometry using far?infrared laser radiation is employed on TEXT?Upgrade to measure the spatial and temporal evolution of the electron density profile as well as small?scale perturbations. Perturbations to the electron density induced by naturally occurring sawtooth oscillations or externally imposed gas modulations can be used to ascertain the local particle flux and transport coefficients in the plasma interior. Density islands associated with Mirnov activity can also be resolved providing detailed information on the density profile at island X and O points. Implementation of a second orthogonal view will allow accurate determination of the density profile in the various asymmetric plasma configurations of TEXT?Upgrade.

D. L. Brower; Y. Jiang; W. A. Peebles; S. Burns; N. C. Luhmann Jr.

1992-01-01T23:59:59.000Z

212

Chiral dynamics and peripheral transverse densities  

SciTech Connect

In the partonic (or light-front) description of relativistic systems the electromagnetic form factors are expressed 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 the peripheral densities at transverse distances b = O(M{sub {pi}}{sup -1}) and compute them in a parametrically controlled manner. A dispersion relation connects the large-distance behavior of the transverse charge and magnetization densities to the spectral functions of the Dirac and Pauli form factors near the two--pion threshold at timelike t = 4 M{ sub {pi}}{sup 2}, which can be computed in relativistic chiral effective field theory. Using the leading-order approximation we (a) derive the asymptotic behavior (Yukawa tail) of the isovector transverse densities in the "chiral" region b = O(M{sub {pi}}{sup -1}) and the "molecular" region b = O(M{sub N}{sup 2}/M{sub {pi}}{sup 3}); (b) perform the heavy-baryon expansion of the transverse densities; (c) explain the relative magnitude of the peripheral charge and magnetization densities in a simple mechanical picture; (d) include Delta isobar intermediate states and study the peripheral transverse densities in the large-N{ sub c} limit of QCD; (e) quantify the region of transverse distances where the chiral components of the densities are numerically dominant; (f) calculate the chiral divergences of the b{sup 2}-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit M{sub {pi}} -> 0 and determine their spatial support. Our approach provides a concise formulation of the spatial structure of the nucleon's chiral component and offers new insights into basic properties of the chiral expansion. It relates the information extracted from low-t elastic form factors to the generalized parton distributions probed in peripheral high-energy scattering processes.

Granados, Carlos G. [Uppsala University (Sweden); Weiss, Christian [JLAB, Newport News, VA (United States)

2014-01-01T23:59:59.000Z

213

Tokamak Equilibria with Reversed Current Density  

Science Journals Connector (OSTI)

Observations of nearly zero toroidal current in the central region of tokamaks (the current hole) raises the question of the existence of toroidal equilibria with very low or reversed current in the core. The solutions of the Grad-Shafranov equilibrium equation with hollow toroidal current density profile including negative current density in the plasma center are investigated. Solutions of the corresponding eigenvalue problem provide simple examples of such equilibrium configurations. More realistic equilibria with toroidal current density reversal are computed using a new equilibrium problem formulation and computational algorithm which do not assume nested magnetic surfaces.

A. A. Martynov; S. Yu. Medvedev; L. Villard

2003-08-21T23:59:59.000Z

214

Instabilities in the Nuclear Energy Density Functional  

E-Print Network (OSTI)

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.

M. Kortelainen; T. Lesinski

2010-02-05T23:59:59.000Z

215

Report of the Interagency Task Force on High Energy Density Physics  

SciTech Connect

Identifies the needs for improving Federal stewardship of specific aspects of high energy density physics, particularly the study of high energy density plasmas in the laboratory, and strengthening university activities in this latter discipline. The report articulates how HEDP fits into the portfolio of federally funded missions and includes agency actions to be taken that are necessary to further this area of study consistent with Federal priorities and plans, while being responsive to the needs of the scientific community.

None

2007-08-01T23:59:59.000Z

216

Compression of Polymer-Coated Laser-Fusion Targets to Ten Times Liquid DT Density  

Science Journals Connector (OSTI)

Polymer-coated glass microspheres filled with DT fuel and argon seed gas were irradiated with the SHIVA 1.06-?m laser using 4-kJ, 200-ps (full width at half maximum), Gaussian pulses. Measured light absorption, x-ray spectrum, neutron yields, and x-ray continuum images compared favorably with detailed computer simulations. Pusher neutron activation and argon line imaging diagnostics were utilized to measure fuel density. Fuel densities of 1-3 g/cm3 or 5-15 times liquid DT density were inferred.

J. M. Auerbach, W. C. Mead, E. M. Campbell, D. L. Matthews, D. S. Bailey, C. W. Hatcher, L. N. Koppel, S. M. Lane, P. H. Y. Lee, K. R. Manes, G. McClellan, D. W. Phillion, R. H. Price, V. C. Rupert, V. W. Slivinsky, and C. D. Swift

1980-06-23T23:59:59.000Z

217

The world's smallest whale population?  

Science Journals Connector (OSTI)

...threats to these whales from ship strikes, disturbance from seismic activities and entanglement in fishing gear. Had no further...and Y. V. Ivashchenko 2009 A whale of a deception. Mar. Fish. Rev 71, 44-52. 5 Yablokov, A. V. 1994 Validity of whaling...

2011-01-01T23:59:59.000Z

218

wave power density | OpenEI  

Open Energy Info (EERE)

power density power density Dataset Summary Description This project estimates the naturally available and technically recoverable U.S. wave energy resources, using a 51-month Wavewatch III hindcast database developed especially for this study by National Oceanographic and Atmospheric Administration's (NOAA's) National Centers for Environmental Prediction. For total resource estimation, wave power density in terms of kilowatts per meter is aggregated across a unit diameter circle. Source Electric Power Research Institute (EPRI) Date Released December 05th, 2011 (2 years ago) Date Updated Unknown Keywords EPRI MHK NREL ocean Virginia Tech wave wave power density Data application/pdf icon Download Full Report (pdf, 8.8 MiB) Quality Metrics Level of Review Some Review Comment

219

Viscosity and Density of Reference Fluid.  

E-Print Network (OSTI)

??The viscosity and density of bis(8-methylnonyl) benzene-1,2- dicarboxylate {diisodecyl phthalate (DIDP)}, with a nominal viscosity at T = 298 K and p = 0.1 MPa (more)

Almotari, Masaed Moti M

2006-01-01T23:59:59.000Z

220

Density controlled carbon nanotube array electrodes  

DOE Patents (OSTI)

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.

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

2008-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS  

E-Print Network (OSTI)

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS KARLHEINZ GR�OCHENIG, GITTA KUTYNIOK's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics

Seip, Kristian

222

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS  

E-Print Network (OSTI)

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS KARLHEINZ GR¨OCHENIG, GITTA KUTYNIOK's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics

Kutyniok, Gitta

223

Electron densities from the Brueckner Doubles method  

Science Journals Connector (OSTI)

The concept of the Brueckner orbital is examined, following a resurgence of ... distinction between Self Consistent Field, Natural and Brueckner orbitals are discussed. Total electron densities are ... are studie...

Caroline M. van Heusden; Rika Kobayashi; Roger D. Amos

1993-07-01T23:59:59.000Z

224

Coal fractionation by density for coking purposes  

Science Journals Connector (OSTI)

Scarce coal with good coking properties may be obtained by separating less valuable coal into different density fractions. The use of valuable fractions released in enrichment ensures optimal coking-batch composi...

S. G. Gagarin

2010-09-01T23:59:59.000Z

225

High density effective theory on the lattice  

E-Print Network (OSTI)

Long-range interactions in finite density QCD necessitate a non-perturbative approach in order to reliably map out the key features and spectrum of the QCD phase diagram. However, the complex nature of the fermion determinant in this sector prohibits the use of established Monte Carlo techniques that utilize importance sampling. Whilst significant progress has been made in the low density, high temperature region, this remains a considerable challenge at mid to high density. At large chemical potential, QCD can be approximated using high density effective theory which is free from the sign problem at leading order. We investigate the implementation of this theory on the lattice in conjunction with existing re-weighting techniques.

A. Dougall

2007-10-08T23:59:59.000Z

226

On coherence in parametric density estimation  

Science Journals Connector (OSTI)

......1990 research-article Miscellanea On coherence in parametric density estimation J...KullbackLeibler directed divergence has this coherence property whereas the corresponding symmetric...estimation is also discussed. Admissibility|Coherence|Kullback-Leibler divergence|Predictive......

J. AITCHISON

1990-12-01T23:59:59.000Z

227

Alpha track density using a semiconductor detector  

E-Print Network (OSTI)

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...

Hamilton, Ian Scott

2012-06-07T23:59:59.000Z

228

High Energy Density Ultracapacitors | Department of Energy  

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

Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. es038smith2010o.pdf More Documents & Publications High Energy Density Ultracapacitors High...

229

High Energy Density Ultracapacitors | Department of Energy  

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

Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. esp22smith.pdf More Documents & Publications High Energy Density Ultracapacitors High Energy...

230

Hydrogen Storage R&D Activities  

Energy.gov (U.S. Department of Energy (DOE))

DOE's hydrogen storage R&D activities are aimed at increasing the gravimetric and volumetric energy density and reducing the cost of hydrogen storage systems for transportation andsmall...

231

Buoyancy-generated variable-density turbulence  

SciTech Connect

Because of the importance of turbulence mixing in many applications, a number of turbulence mixing models have been proposed for variable- density flows. These engineering models (one- point statistical models) typically include the transport of the turbulent kinetic energy and the turbulent energy dissipation rate (i.e., k - {epsilon} models). The model presented by Besnard, Harlow, Rauenzahn and Zemach (1992) (herein referred to as BHRZ) is a one-point model intended to describe variable-density turbulent flows. Transport equations for the Reynolds stress tensor, R{sub ij}, and the turbulent energy dissipation rate, the density-velocity correlation, a{sub i}, and the density-specific volume correlation, b are derived. This model employs- techniques and concepts from incompressible, constant- density turbulence modeling and incorporates ideas from two-phase flow models. Clark and Spitz (1994) present a two-point model for variable-density turbulence. Their derivation is based on transport equations that, are based 0481 on two-point- generalizations of R{sub ij}, a{sub ij}, and b. These equations are Fourier transformed with respect to the separation distance between the two points. Transport equations are derived for R{sub ij}, a{sub i}, b. As in the one-point model, this model contains many ad-hoc assumptions and unknown model coefficients that must be determined by comparison with experimental and numerical data. However, the two-point formalism requires fewer equilibrium assumptions then does a single-point model. Our primary concern in this paper lies in the nonlinear processes of turbulence and the influence of large density variations (not within the Boussinesq limit) on these processes. To. isolate the effects of variable-density on the turbulence we restrict our flow to be incompressible, statistically homogeneous buoyancy-generated. turbulence. To our knowledge there have not been any simulations reported for this problem.

Sandoval, D.L.; Clark, T.T.; Riley, J.J.

1996-07-01T23:59:59.000Z

232

Origin of Tokamak Density Limit Scalings  

Science Journals Connector (OSTI)

The onset criterion for radiation driven islands [P.?H. Rebut and M. Hugon, Plasma Physics and Controlled Nuclear Fusion Research 1984: Proc. 10th Int. Conf. London, 1984, (IAEA, Vienna, 1985), Vol.2] in combination with a simple cylindrical model of tokamak current channel behavior is consistent with the empirical scaling of the tokamak density limit [M. Greenwald, Nucl. Fusion 28, 2199 (1988)]. Many other unexplained phenomena at the density limit are consistent with this novel physics mechanism.

D. A. Gates and L. Delgado-Aparicio

2012-04-20T23:59:59.000Z

233

The Chemistry of Atherogenic High Density Lipoprotein  

E-Print Network (OSTI)

TRL Bouyant triglyceride-rich lipoprotein C18 Carbon tail of eighteen atoms CE Capillary electrophoresis CETP Cholesterol ester transfer protein CM Chylomicrons CsCdY dicesium cadmium ethylenediaminetetraacetic acid CAD Coronary artery disease CVD... Cardiovascular disease DGU Density gradient ultracentrifugation I-DGU Immunospecific-density gradient ultracentrifugation DMSO Dimethyl sulfoxide DS Dextran sulfate dTRL Dense triglyceride rich lipoprotein EDTA Ethyelenediaminetetraacetic acid HDL High...

Moore, D'Vesharronne J.

2012-07-16T23:59:59.000Z

234

Bone Mineral Density in Women with Depression  

Science Journals Connector (OSTI)

...illness and the normal women were individually matched for age, body-mass index, and menstrual status; women with many of the risk factors associated with decreased bone mineral density were excluded; dual-energy x-ray absorptiometry was used to measure bone density at the spine, hip, and radius; and bone... Major depression is a complex disorder reflecting genetic, developmental, and environmental factors. Although its pathophysiology is not clearly understood, depression is associated with hypothalamic dysfunction specifically, hypercortisolism, the ...

Michelson D.; Stratakis C.; Hill L.

1996-10-17T23:59:59.000Z

235

A Decade of Population Change in Texas.  

E-Print Network (OSTI)

population, particularly from 1950 to 1960. It includes selected popula- tion projections to 1970 and points out some of their implications. Among the more significant findings are the following : 1. The total population of Texas on April 1, 1960, was 9... and communications facilities will have to be expanded to meet the needs of rapidly-growing numbers of people. 2. Population growth and losses are unevenly distributed in the State. Between 1950 and 1960, 143 Texas counties lost in population and 111 had...

Skrabanek, R. L.

1963-01-01T23:59:59.000Z

236

Nuclear energy density optimization: Shell structure  

E-Print Network (OSTI)

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.

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

2013-12-06T23:59:59.000Z

237

ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY  

E-Print Network (OSTI)

Chapter 5 ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY Yan Alexander Wang and Emily A Theory (DFT), there was the Thomas-Fermi (TF) model, which uses the electron density ¢¡ r£ (a function-dependent DFT Density-Functional Theory DI density-independent DM1 first-order reduced density matrix EDF energy

Wang, Yan Alexander

238

A Bayesian Probability Calculus for Density Matrices  

E-Print Network (OSTI)

One of the main concepts in quantum physics is a density matrix, which is a symmetric positive definite matrix of trace one. Finite probability distributions are a special case where the density matrix is restricted to be diagonal. Density matrices are mixtures of dyads, where a dyad has the form uu' for any any unit column vector u. These unit vectors are the elementary events of the generalized probability space. Perhaps the simplest case to see that something unusual is going on is the case of uniform density matrix, i.e. 1/n times identity. This matrix assigns probability 1/n to every unit vector, but of course there are infinitely many of them. The new normalization rule thus says that sum of probabilities over any orthonormal basis of directions is one. We develop a probability calculus based on these more general distributions that includes definitions of joints, conditionals and formulas that relate these, i.e. analogs of the theorem of total probability, various Bayes rules for the calculation of posterior density matrices, etc. The resulting calculus parallels the familiar 'classical' probability calculus and always retains the latter as a special case when all matrices are diagonal. Whereas the classical Bayesian methods maintain uncertainty about which model is 'best', the generalization maintains uncertainty about which unit direction has the largest variance. Surprisingly the bounds also generalize: as in the classical setting we bound the negative log likelihood of the data by the negative log likelihood of the MAP estimator.

Manfred K. Warmuth; Dima Kuzmin

2014-08-09T23:59:59.000Z

239

First gamma-ray bursts imprinting population III progenitor structure  

Science Journals Connector (OSTI)

One of the most important goals in modern cosmology is to understand how the first stars formed at the end of the dark ages. The first stars so-called Population III (Pop III) are predicted to have been predominantly very massive. Provided such very massive stars would produce a collapsar and relativistic jets the burst of high-energy photons like gamma-ray bursts (GRBs) could be observable. In this study we investigate the possibility of shock propagation through a massive envelope calculated using the density structure of Pop III star in analytic way. In addition we perform the numerical simulations of relativistic jet propagation in the Pop III.1 and Pop III.2 stars.

2012-01-01T23:59:59.000Z

240

Population, Economy and Energy Uses Influence on Sulfur Emissions in the United States Since 1900  

E-Print Network (OSTI)

This paper seeks to identify how changes in population, economic activity, and energy use have influenced sulfur emissions during this century. A linear model is presented which characterizes sulfur emissions as the product of these driving forces...

Kissock, J. K.; Husar, R. B.

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

80% of the US population lives in urban areas. The increasing population density and expanding area of cities has contributed to pressure from federal and state mandates that  

E-Print Network (OSTI)

under plants more moist, and spaces between plants more dry. 3. After grass is removed, widely spaced transformations will occur at a higher rate and lead to faster accumulation of inorganic N in soils. Broader-services. · If xeriscapes create a tradeoff between water quality and water use savings, then this type of landscape

Hall, Sharon J.

242

The oral health and dental characteristics of a Mimbres population from Southwest New Mexico  

E-Print Network (OSTI)

an impact on the susceptibility of teeth to develop dental caries Studies have shown that the chemical composition of teeth changes over time, to become more caries resistant. With inczeasing age, there is a decrease in the density of teeth in con...THE ORAL HEALTH AND DENTAL CHARACTERISTICS OF A MIMBRES POPULATION FROM SOUTHWEST NEW MEXICO A Thesis by BEN WILLIAM OLIVE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...

Olive, Ben W

1989-01-01T23:59:59.000Z

243

Cancer Epidemiology Population Health Sciences 750  

E-Print Network (OSTI)

-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

Sheridan, Jennifer

244

Fish Population and Behavior Revealed by Instantaneous  

E-Print Network (OSTI)

Fish Population and Behavior Revealed by Instantaneous Continental Shelf­Scale Imaging Nicholas C-transect methods from slow-moving research vessels. These methods significantly undersample fish populations in time and space, leaving an incomplete and ambiguous record of abundance and behavior. We show that fish

245

Population growth and earth's human carrying capacity  

Science Journals Connector (OSTI)

...projected world grain har-vest of 2.1 billion tons in 2030 could feed 2.5 billion people at the U.S...Sustainable risks: An enduring given) (Sdu Uitgeverij Plantijnstraat, Den...estimated a maximum world population of 2 billion. The world's population...

JE Cohen

246

Oil Pollution and Seabird Populations [and Discussion  

Science Journals Connector (OSTI)

1 June 1982 research-article Oil Pollution and Seabird Populations [and...time to time by individual incidents of oil pollution, and throughout the year, especially...deal of public concern about the effect of oil pollution on the wellbeing of seabird populations...

1982-01-01T23:59:59.000Z

247

High-Energy-Density Plasmas, Fluids  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Energy-Density Plasmas, Fluids High-Energy-Density Plasmas, Fluids /science-innovation/_assets/images/icon-science.jpg High-Energy-Density Plasmas, Fluids National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. TRIDENT target chamber Sasi Palaniyappan, right, and Rahul Shah left inside a target chamber where the TRIDENT short pulse laser is aimed at a very thin diamond- foil target, a fraction of a micrometer thick. The laser delivers a power on target of 150 Terawatts focused into a 7 micrometer spot, yielding laser brilliance over 100 times more intense than needed to make the target electrons fully relativistic. These experiments test novel methods of producing intense

248

Neutron Matter from Low to High Density  

E-Print Network (OSTI)

Neutron matter is an intriguing nuclear system with multiple connections to other areas of physics. Considerable progress has been made over the last two decades in exploring the properties of pure neutron fluids. Here we begin by reviewing work done to explore the behavior of very low density neutron matter, which forms a strongly paired superfluid and is thus similar to cold Fermi atoms, though at energy scales differing by many orders of magnitude. We then increase the density, discussing work that ties the study of neutron matter with the determination of the properties of neutron-rich nuclei and neutron-star crusts. After this, we review the impact neutron matter at even higher densities has on the mass-radius relation of neutron stars, thereby making contact with astrophysical observations.

Gandolfi, Stefano; Carlson, J

2015-01-01T23:59:59.000Z

249

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

SciTech Connect

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.

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

2014-01-01T23:59:59.000Z

250

Hall viscosity, spin density, and torsion  

E-Print Network (OSTI)

We investigate the relationship between Hall viscosity, spin density and response to geometric torsion. For the most general effective action for relativistic gapped systems, the presence of non-universal terms implies that there is no relationship between torsion response and Hall viscosity. We also consider free relativistic and non-relativistic microscopic actions and again verify the existence of analogous non-universal couplings. Explicit examples demonstrate that torsion response is unrelated to both Hall viscosity and spin density. We also argue that relativistic gapped theories must have vanishing Hall viscosity in Lorentz invariant vacuums.

Geracie, Michael; Roberts, Matthew M

2014-01-01T23:59:59.000Z

251

Density Perturbations in the Ekpyrotic Scenario  

E-Print Network (OSTI)

We study the generation of density perturbations in the ekpyrotic scenario for the early universe, including gravitational backreaction. We expose interesting subtleties that apply to both inflationary and ekpyrotic models. Our analysis includes a detailed proposal of how the perturbations generated in a contracting phase may be matched across a `bounce' to those in an expanding hot big bang phase. For the physical conditions relevant to the ekpyrotic scenario, we re-obtain our earlier result of a nearly scale-invariant spectrum of energy density perturbations. We find that the perturbation amplitude is typically small, as desired to match observation.

Justin Khoury; Burt A. Ovrut; Paul J. Steinhardt; Neil Turok

2001-09-06T23:59:59.000Z

252

Josephson oscillations of charge density waves  

SciTech Connect

The formation of charge density waves in solids was originally proposed as a possible mechanism for superconductivity by Froehlich. Although the experimentally discovered materials with charge density waves (CDW)s are found to have finite resistivity as a result of impurity pinning, they nevertheless reveal many interesting features including motion which is analogous to a resistively shunted Josephson junction of superconductors. The noise spectrum of CDW systems is reviewed with particular emphasis on interactions with normal as well as magnetic impurities. Future prospects for observing an amplitude variation of the noise signals induced by a magnetic field are proposed.

Ruvalds, J.; Tua, P.F.

1985-01-01T23:59:59.000Z

253

Low density, microcellular foams, preparation, and articles  

DOE Patents (OSTI)

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.

Young, A.T.

1982-03-03T23:59:59.000Z

254

Energy and Momentum Density in Field Theory  

Science Journals Connector (OSTI)

It is shown that the energy density commutator condition in its simplest form is valid for interacting spin 0, , 1 field systems, but not for higher spin fields. The action principle is extended, for this purpose, to arbitrary coordinate frames. There is a discussion of four categories of fields and some explicit consideration of spin 32 as the simplest example that gives additional terms in the energy density commutator. As the fundamental equation of relativistic quantum field theory, the commutator condition makes explicit the greater physical complexity of higher spin fields.

Julian Schwinger

1963-04-15T23:59:59.000Z

255

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

256

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

E-Print Network (OSTI)

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

Goldschmidt, Christina

257

Time Dependent Density Functional Theory Application to Extended Systems  

E-Print Network (OSTI)

Time Dependent Density Functional Theory Application to Extended Systems Francesco Sottile Facility (ETSF) Donostia, 25 July 2007 Time Dependent Density Functional Theory Francesco Sottile #12 Density Functional Theory Francesco Sottile #12;Linear Periodic systems ALDA The Quest for the Holy

Botti, Silvana

258

Mechanical constraints enhance electrical energy densities of soft dielectrics  

E-Print Network (OSTI)

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

Ferrari, Silvia

259

High-power-density spot cooling using bulk thermoelectrics  

E-Print Network (OSTI)

3D electrothermal model, the cooling power densities of themax , and increasing the cooling power densities 224 times.the advantages of high cooling power densities and is less

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

2004-01-01T23:59:59.000Z

260

neutron density. The neutron density (nn) of the source was modeled by solving the simul-  

E-Print Network (OSTI)

neutron density. The neutron density (nn) of the source was modeled by solving the simul- taneousT is the thermal neutron velocity, l is the decay constant, Ns is the s-process abun- dance, bs� is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re

West, Stuart

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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

E-Print Network (OSTI)

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.

Thomas H. Reiprich

2002-07-02T23:59:59.000Z

262

Health care Passport: A population-based introductory pharmacy practice model for Medicare beneficiaries  

Science Journals Connector (OSTI)

Abstract The objective of the study was to describe the design and outcomes of a model to provide population-based, introductory pharmacy practice experiences (IPPEs). Community outreach events targeting Medicare beneficiaries were conducted. Screenings and services designed for adults 65 years and older were offered. Attendees were provided a business card known as the Health care Passport which identified screening stations and provided space to record results. Students participated in planning the events and providing health services. Students gained experience with population-based care, providing 2633 health screenings for 1013 attendees, and earned 2650 IPPE hours. Attendees received medication therapy management, assistance with the Medicare Part D plan review, and utilized an average of three stations, most commonly cardiovascular risk, immunizations, diabetes, and bone density. The Health care Passport is a reproducible model to provide extensive, population-based health screenings and services and effectively meet IPPE requirements for students.

Sian M. Carr-Lopez; Joseph A. Woelfel; Michael Shioji; Marlyn Nicolas; Dina Hoang; Jennifer Rodriguez; Neha Rahan; Rajul A. Patel; Suzanne M. Galal

2014-01-01T23:59:59.000Z

263

DERIVING PLASMA DENSITIES AND ELEMENTAL ABUNDANCES FROM SERTS DIFFERENTIAL EMISSION MEASURE ANALYSIS  

SciTech Connect

We use high-resolution spectral emission line data obtained by the SERTS instrument during three rocket flights to demonstrate a new approach for constraining electron densities of solar active region plasma. We apply differential emission measure (DEM) forward-fitting techniques to characterize the multithermal solar plasma producing the observed EUV spectra, with constraints on the high-temperature plasma from the Yohkoh Soft X-ray Telescope. In this iterative process, we compare line intensities predicted by an input source distribution to observed line intensities for multiple iron ion species, and search a broad range of densities to optimize {chi}{sup 2} simultaneously for the many available density-sensitive lines. This produces a density weighted by the DEM, which appears to be useful for characterizing the bulk of the emitting plasma over a significant range of temperature. This 'DEM-weighted density' technique is complementary to the use of density-sensitive line ratios and less affected by uncertainties in atomic data and ionization fraction for any specific line. Once the DEM shape and the DEM-weighted density have been established from the iron lines, the relative elemental abundances can be determined for other lines in the spectrum. We have also identified spectral lines in the SERTS wavelength range that may be problematic.

Schmelz, J. T.; Kimble, J. A. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Saba, J. L. R., E-mail: jschmelz@memphis.edu [Astronomy Department, University of Maryland, College Park, MD 20742 (United States)

2012-09-20T23:59:59.000Z

264

Novel and Optimized Materials Phases for High Energy Density...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Novel and Optimized Materials Phases for High Energy Density Batteries Novel and Optimized Materials Phases for High Energy Density Batteries 2013 DOE Hydrogen and Fuel Cells...

265

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

NLE Websites -- All DOE Office Websites (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...

266

Engineering Density of States of Earth Abundant Semiconductors...  

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

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

267

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...

268

Density Functional Theory Approach to Nuclear Fission  

E-Print Network (OSTI)

The Skyrme nuclear energy density functional theory (DFT) is used to model neutron-induced fission in actinides. This paper focuses on the numerical implementation of the theory. In particular, it reports recent advances in DFT code development on leadership class computers, and presents a detailed analysis of the numerical accuracy of DFT solvers for near-scission calculations.

N. Schunck

2013-01-20T23:59:59.000Z

269

Modern applications of covariant density functional theory  

E-Print Network (OSTI)

Modern applications of Covariant Density Functional Theory (CDFT) are discussed. First we show a systematic investigation of fission barriers in actinide nuclei within constraint relativistic mean field theory allowing for triaxial deformations. In the second part we discuss a microscopic theory of quantum phase transitions (QPT) based on the relativistic generator coordinate method.

P. Ring; H. Abusara; A. V. Afanasjev; G. A. Lalazissis; T. Niksic; D. Vretenar

2011-09-19T23:59:59.000Z

270

Thermal conductivity of low density carbon aerogels  

Science Journals Connector (OSTI)

Carbon aerogels with densities ranging from 0.182 to 0.052g/cm3, pore sizes ranging from 88 to 227nm, and particle diameters ranging from 20 to 13nm were prepared. Thermal conductivity measurements by laser fl...

Junzong Feng; Jian Feng; Changrui Zhang

2012-10-01T23:59:59.000Z

271

Estimating density of Florida Key deer  

E-Print Network (OSTI)

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...

Roberts, Clay Walton

2006-08-16T23:59:59.000Z

272

Density Perturbations for Running Cosmological Constant  

E-Print Network (OSTI)

The dynamics of density and metric perturbations is investigated for the previously developed model where the decay of the vacuum energy into matter (or vice versa) is due to the renormalization group (RG) running of the cosmological constant (CC) term. The evolution of the CC depends on the single parameter \

Julio C. Fabris; Ilya L. Shapiro; Joan Sola

2007-01-26T23:59:59.000Z

273

Drawing Electron Density Maps Tutorial : J. Reibenspies  

E-Print Network (OSTI)

file Choose the difference map #12;Step 2 · If necessary generate full molecule in XSEED or XP shift key to pan) #12;Step 4 · All ball and stick plot to spice it up ZOOMED #12;Step 5 · Save screen the electron density in the macocyclic void in order to understand the disorder #12;Step one · In the INS

Meagher, Mary

274

Master's Thesis Density Functional Theory for  

E-Print Network (OSTI)

of the information found during my work. v #12;vi #12;Contents Abstract #12;Abstract This thesis presents a number of results for basic quantum mechanical models intended to be used in the development of density functional theory for systems with edges. Following previous work

Armiento, Rickard

275

Energy-Density Relation for Nuclear Matter  

Science Journals Connector (OSTI)

In most previous calculations of nuclear matter the energy has been calculated only at the equilibrium density, which density has been determined by a minimum condition. In the present paper the author's theory of nuclear matter is applied to a study of the complete energy-density relation of nuclear matter, in the neighborhood of the equilibrium density. The emphasis here is not upon duplicating the accepted value for the equilibrium binding energy, but rather upon a study of the leading (diagonal) contribution of the quasi-particle interaction term g1(k1k2|k3k4), which is the matrix element of a reaction matrix G1. It is shown that g1(k1k2|k1k2) must be evaluated partly by using observed nucleon-nucleon scattering phase shifts and partly by calculating the close-in behavior of the two-nucleon wave function, and that this second part receives a large contribution from the deuteron state. Curves are given for the dependence of g1(k1k2|k1k2) on the density and the center-of-mass momentum. It is also shown that g1(k1k2|k1k2) is sensitive to the size of the nucleon repulsive core, but not upon the character of the attraction, when agreement with scattering data has first been achieved. Finally, a comparison of g1(k1k2|k1k2) with the prediction of first-order perturbation theory is made.

Franz Mohling

1962-11-01T23:59:59.000Z

276

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

E-Print Network (OSTI)

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

Forbes, Jeffrey

277

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

E-Print Network (OSTI)

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

Feenstra, Randall

278

Hanford Site Regional Population - 2010 Census  

SciTech Connect

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.

Hamilton, Erin L.; Snyder, Sandra F.

2011-08-12T23:59:59.000Z

279

The red and blue galaxy populations in the GOODS field: evidence for an excess of red dwarfs  

E-Print Network (OSTI)

We study the evolution of the galaxy population up to z\\sim3 as a function of its colour properties. In particular, luminosity functions and luminosity densities have been derived as a function of redshift for the blue/late and red/early populations. We use data from the GOODS-MUSIC catalogue which have typical magnitude limits zred/early subsamples. The LFs of the blue/late and total samples are well represented by steep Schechter functions evolving in luminosity with increasing redshifts. The volume density of the LFs of the red/early populations decreases with increasing redshift. The shape of the red/early LFs shows an excess of faint red dwarfs with respect to the extrapolation of a flat Schechter function and can be represented by the sum of two Schechter functions. Our model for galaxy formation in the hierarchical clustering scenario, which also includes external feedback due to a diffuse UV background, shows a general broad agreement with the LFs of both populations, the larger discrepancies being present at the faint end for the red population. Hints on the nature of the red dwarf population are given on the basis of their stellar mass and spatial distributions.

S. Salimbeni; E. Giallongo; N. Menci; M. Castellano; A. Fontana; A. Grazian; L. Pentericci; D. Trevese; S. Cristiani; M. Nonino; E. Vanzella

2007-10-19T23:59:59.000Z

280

The problem of the universal density functional and the density matrix functional theory  

SciTech Connect

The analysis in this paper shows that the Hohenberg-Kohn theorem is the constellation of two statements: (i) the mathematically rigorous Hohenberg-Kohn lemma, which demonstrates that the same ground-state density cannot correspond to two different potentials of an external field, and (ii) the hypothesis of the existence of the universal density functional. Based on the obtained explicit expression for the nonrel-ativistic particle energy in a local external field, we prove that the energy of the system of more than two non-interacting electrons cannot be a functional of the inhomogeneous density. This result is generalized to the system of interacting electrons. It means that the Hohenberg-Kohn lemma cannot provide justification of the universal density functional for fermions. At the same time, statements of the density functional theory remain valid when considering any number of noninteracting ground-state bosons due to the Bose condensation effect. In the framework of the density matrix functional theory, the hypothesis of the existence of the universal density matrix functional corresponds to the cases of noninteracting particles and to interaction in the Hartree-Fock approximation.

Bobrov, V. B., E-mail: vic5907@mail.ru; Trigger, S. A., E-mail: satron@mail.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2013-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Design for a Longitudinal Density Monitor for the LHC  

SciTech Connect

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.

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

282

Hydrogen density of states and defects densities in a-Si:H  

SciTech Connect

The properties of hydrogenated amorphous silicon (a-Si:H) and its devices depend fundamentally on the density of states (DOS) in the gap due to dangling bonds. It is generally believed that the density of dangling bonds is controlled by a chemical equilibrium with the weak Si-Si bonds which form the localized valence band tail states. Further details are given of a unified model of the hydrogen density of states and defect pool of a-Si:H. The model is compared to other defect models and extended to describe a-Si alloys and the creation of valence band tail states during growth.

Deane, S.C.; Powell, M.J. [Philips Research Labs., Redhill, Surrey (United Kingdom); Robertson, J. [Cambridge Univ. (United Kingdom). Engineering Dept.

1996-12-31T23:59:59.000Z

283

Estimating population size by genotyping faeces  

Science Journals Connector (OSTI)

...CA 91360, USA Population size is a fundamental biological parameter that is di cult...In Ecological census techniques, a handbook (ed. W. J. Sutherland), pp. 11...In Ecological census techniques, a handbook (ed. W. J. Sutherland), pp. 1...

1999-01-01T23:59:59.000Z

284

Ocean currents help explain population genetic structure  

Science Journals Connector (OSTI)

...original work is properly cited. Ocean currents help explain population genetic...larval dispersal estimates based on ocean current observations, we demonstrate...Data-assimilated models of ocean currents for the study region were produced...

2010-01-01T23:59:59.000Z

285

Metabolic Gene Polymorphism Frequencies in Control Populations  

Science Journals Connector (OSTI)

...collaboration with the GSEC Project. 1 Vineis, P., Malats...2000. 9 Taioli E. International collaborative study...Malats N., Camus-Radon A. M., Nyberg F...populations. | Using the International Project on Genetic Susceptibility...

Seymour Garte; Laura Gaspari; Anna-Karin Alexandrie; Christine Ambrosone; Herman Autrup; Judith L. Autrup; Helena Baranova; Lise Bathum; Simone Benhamou; Paolo Boffetta; Christine Bouchardy; Katja Breskvar; Jurgen Brockmoller; Ingolf Cascorbi; Margie L. Clapper; Christiane Coutelle; Ann Daly; Marco DellOmo; Vita Dolzan; Carolyn M. Dresler; Anthony Fryer; Aage Haugen; David W. Hein; Allan Hildesheim; Ari Hirvonen; Ling-Ling Hsieh; Magnus Ingelman-Sundberg; Ivan Kalina; Daehee Kang; Masahiro Kihara; Chikako Kiyohara; Pierre Kremers; Philip Lazarus; Loc Le Marchand; Maria Celeste Lechner; Ester M. M. van Lieshout; Stephanie London; Johannes J. Manni; Christine M. Maugard; Shunji Morita; Valle Nazar-Stewart; Kazumasa Noda; Yoshio Oda; Fritz F. Parl; Roberta Pastorelli; Irene Persson; Wilbert H. M. Peters; Agneta Rannug; Timothy Rebbeck; Angela Risch; Liliane Roelandt; Marjorie Romkes; David Ryberg; Jan Salagovic; Bernadette Schoket; Janeric Seidegard; Peter G. Shields; Edith Sim; Daniel Sinnet; Richard C. Strange; Isabel Stcker; Haruhiko Sugimura; Jordi To-Figueras; Paolo Vineis; Mimi C. Yu; and Emanuela Taioli

2001-12-01T23:59:59.000Z

286

The genetics of Drosophila subobscura populations  

Science Journals Connector (OSTI)

The natural population of Drosophila subobscura of Mt. Parnes has been followed for two successive years and the frequency of the gene arrangements determined. Some changes occured in the first year but do not ex...

Costas B. Krimbas

287

United Nations Population Information Network | Open Energy Information  

Open Energy Info (EERE)

United Nations Population Information Network United Nations Population Information Network Jump to: navigation, search Tool Summary LAUNCH TOOL Name: United Nations Population Information Network Agency/Company /Organization: United Nations Focus Area: People and Policy Resource Type: Dataset Website: www.un.org/popin/ Cost: Free United Nations Population Information Network Screenshot References: United Nations Population Information Network[1] Logo: United Nations Population Information Network The Population Information Network (POPIN) strives to make international, regional and national population information, particularly information available from United Nations sources, easily available to the international community. "The Population Information Network (POPIN) was founded on 9 May 1979, by

288

Population viability analysis of the Endangered shortnose sturgeon  

SciTech Connect

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.

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

2011-07-01T23:59:59.000Z

289

A density-independent glass transition in biological tissues  

E-Print Network (OSTI)

Cells must move through tissues in many important biological processes, including embryonic development, cancer metastasis, and wound healing. In these tissues, a cell's motion is often strongly constrained by its neighbors, leading to glassy dynamics. Recent work has demonstrated the existence of a non-equilibrium glass transition in self-propelled particle models for active matter, where the transition is driven by changes in density. However, this may not explain liquid-to-solid transitions in confluent tissues, where there are no gaps between cells and the packing fraction remains fixed and equal to unity. Here we demonstrate the existence of a different type of glass transition that occurs in the well-studied vertex model for confluent tissue monolayers. In this model, the onset of rigidity is governed by changes to single-cell properties such as cell-cell adhesion, cortical tension, and volume compressibility, providing an explanation for a liquid-to-solid transitions in confluent tissues.

Bi, Dapeng; Schwarz, J M; Manning, M Lisa

2014-01-01T23:59:59.000Z

290

Global coherence of dust density waves  

SciTech Connect

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.

Killer, Carsten; Melzer, Andr [Institut fr Physik, Ernst-Moritz-Arndt-Universitt Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

291

Ultra-high density diffraction grating  

SciTech Connect

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.

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

2012-12-11T23:59:59.000Z

292

The string of variable density: Further results  

Science Journals Connector (OSTI)

We analyze the problem of calculating the solutions and the spectrum of a string with arbitrary density and fixed ends. We build a perturbative scheme which uses a basis of WKB-type functions and obtain explicit expressions for the eigenvalues and eigenfunctions of the string. Using this approach we show that it is possible to derive the asymptotic (high energy) behavior of the string, obtaining explicit expressions for the first three coefficients (the first two can also be obtained with the WKB method). Finally, using an iterative approach we also obtain analytical expressions for the low energy behavior of the eigenvalues and eigenfunctions of a string with rapidly oscillating density, recovering (in a simpler way) results in the literature.

Paolo Amore

2011-01-01T23:59:59.000Z

293

The string of variable density: further results  

E-Print Network (OSTI)

We analyze the problem of calculating the solutions and the spectrum of a string with arbitrary density and fixed ends. We build a perturbative scheme which uses a basis of WKB-type functions and obtain explicit expressions for the eigenvalues and eigenfunctions of the string. Using this approach we show that it is possible to derive the asymptotic (high energy) behavior of the string, obtaining explicit expressions for the first three coefficients (the first two can also be obtained with the WKB method). Finally using an iterative approach we also obtain analytical expressions for the low energy behavior of the eigenvalues and eigenfunctions of a string with rapidly oscillating density, recovering (in a simpler way) results in the literature.

Paolo Amore

2010-10-24T23:59:59.000Z

294

DENSITY FUNCTIONAL THEORY OF NORMAL AND SUPERCONDUCTING ELECTRON LIQUIDS: EXPLICIT  

E-Print Network (OSTI)

DENSITY FUNCTIONAL THEORY OF NORMAL AND SUPERCONDUCTING ELECTRON LIQUIDS: EXPLICIT FUNCTIONALS VIA?th University Nathan, Queensland 4111, Australia Abstract The basic idea of density functional theory is to map potential which is a functional of the density. The central task of density functional theory is to #12;nd

Gross, E.K.U.

295

ELECTRON DENSITY FLUCTUATIONS AND FLUCTUATION-INDUCED TRANSPORT  

NLE Websites -- All DOE Office Websites (Extended Search)

. . . . . . . . . . . . . . . . . 109 6 Fluctuations and Fluctuation-Induced Particle Transport 110 6.1 Electron Density Fluctuations . . . . . . . . . . . . . . . . . . . . . . ....

296

Energy-momentum Density of Gravitational Waves  

E-Print Network (OSTI)

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.

Amir M. Abbassi; Saeed Mirshekari

2014-11-29T23:59:59.000Z

297

Density matrix minimization with $\\ell_1$ regularization  

E-Print Network (OSTI)

We propose a convex variational principle to find sparse representation of low-lying eigenspace of symmetric matrices. In the context of electronic structure calculation, this corresponds to a sparse density matrix minimization algorithm with $\\ell_1$ regularization. The minimization problem can be efficiently solved by a split Bergman iteration type algorithm. We further prove that from any initial condition, the algorithm converges to a minimizer of the variational principle.

Rongjie Lai; Jianfeng Lu; Stanley Osher

2014-03-06T23:59:59.000Z

298

Density waves in a transverse electric field  

Science Journals Connector (OSTI)

In a quasi-one-dimensional conductor with an open Fermi surface, a charge- or a spin-density-wave phase can be destroyed by an electric field perpendicular to the direction of high conductivity. This mechanism, due to the breakdown of electron-hole symmetry, is very similar to the orbital destruction of superconductivity by a magnetic field, due to time-reversal symmetry.

Gilles Montambaux

1996-12-15T23:59:59.000Z

299

Energy-Momentum Density of Gravitational Waves  

E-Print Network (OSTI)

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.

Amir M. Abbassi; Saeed Mirshekari

2009-08-03T23:59:59.000Z

300

High Energy Density Utracapacitors: Low-Cost, High Energy and Power Density, Nanotube-Enhanced Ultracapacitors  

SciTech Connect

Broad Funding Opportunity Announcement Project: FastCAP is improving the performance of an ultracapacitora battery-like electronic device that can complement, and possibly even replace, an HEV or EV battery pack. Ultracapacitors have many advantages over conventional batteries, including long lifespans (over 1 million cycles, as compared to 10,000 for conventional batteries) and better durability. Ultracapacitors also charge more quickly than conventional batteries, and they release energy more quickly. However, ultracapacitors have fallen short of batteries in one key metric: energy densityhigh energy density means more energy storage. FastCAP is redesigning the ultracapacitors internal structure to increase its energy density. Ultracapacitors traditionally use electrodes made of irregularly shaped, porous carbon. FastCAPs ultracapacitors are made of tiny, aligned carbon nanotubes. The nanotubes provide a regular path for ions moving in and out of the ultracapacitors electrode, increasing the overall efficiency and energy density of the device.

None

2010-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Early Type Galaxy Core Phase Densities  

E-Print Network (OSTI)

Early type galaxies, ellipticals and S0's, have two distinct core density profiles, either a power law or nearly flat in projection. The two core types are distributed with substantial overlap in luminosity, radius, mass and velocity dispersion, however, the cores separate into two distinct distributions in their coarse grain phase density, Q_0 = rho/sigma^3,suggesting that dynamical processes played a dominant role in their origin. The transition phase density separating the two elliptical types is approximately 0.003 M_sun pc^-3 km^-3 s^3,. The Q_0*M_c^2 vs M_c diagram shows that globular clusters, nuclear star clusters and power-law cores fall on what is likely a "collisional" sequence of inspiralling globular clusters. on which the relative core mass excess varies as the bulk stellar mass to the -0.34+/-0.08 power, close to predictions, albeit with a correlation coefficient of -0.46. Both power-law and cored galaxies lie on a single sequence of approximately Q_0 ~r_c^-2.2, suggesting that transport proces...

Carlbeg, Raymond

2014-01-01T23:59:59.000Z

302

The string of variable density: Further results  

SciTech Connect

We analyze the problem of calculating the solutions and the spectrum of a string with arbitrary density and fixed ends. We build a perturbative scheme which uses a basis of WKB-type functions and obtain explicit expressions for the eigenvalues and eigenfunctions of the string. Using this approach we show that it is possible to derive the asymptotic (high energy) behavior of the string, obtaining explicit expressions for the first three coefficients (the first two can also be obtained with the WKB method). Finally, using an iterative approach we also obtain analytical expressions for the low energy behavior of the eigenvalues and eigenfunctions of a string with rapidly oscillating density, recovering (in a simpler way) results in the literature. - Highlights: > We devise a perturbative approach to finding the modes of a string with arbitrary density. > We obtain explicitly the first three coefficients of the asymptotic high energy expansion. > We apply our findings to a series of examples, obtaining both analytical and numerical results.

Amore, Paolo, E-mail: paolo.amore@gmail.com

2011-09-15T23:59:59.000Z

303

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

E-Print Network (OSTI)

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.

T. Thomas; P. Katgert

2005-10-10T23:59:59.000Z

304

Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis  

E-Print Network (OSTI)

Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified resistor lattice indicate that the transversal effect increases as soil bulk density decreases. Measurement of dry sand showed a negative correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal settings. The decrease in the transversal signal was smaller than expected. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not significant to bulk density changes.

Andrea Sz. Kishne; Cristine L. S. Morgan; Hung-Chih Chang; Laszlo B. Kish

2007-05-03T23:59:59.000Z

305

Why do ultrasoft repulsive particles cluster and crystallize? Analytical results from density functional theory  

E-Print Network (OSTI)

We demonstrate the accuracy of the hypernetted chain closure and of the mean-field approximation for the calculation of the fluid-state properties of systems interacting by means of bounded and positive-definite pair potentials with oscillating Fourier transforms. Subsequently, we prove the validity of a bilinear, random-phase density functional for arbitrary inhomogeneous phases of the same systems. On the basis of this functional, we calculate analytically the freezing parameters of the latter. We demonstrate explicitly that the stable crystals feature a lattice constant that is independent of density and whose value is dictated by the position of the negative minimum of the Fourier transform of the pair potential. This property is equivalent with the existence of clusters, whose population scales proportionally to the density. We establish that regardless of the form of the interaction potential and of the location on the freezing line, all cluster crystals have a universal Lindemann ratio L = 0.189 at freezing. We further make an explicit link between the aforementioned density functional and the harmonic theory of crystals. This allows us to establish an equivalence between the emergence of clusters and the existence of negative Fourier components of the interaction potential. Finally, we make a connection between the class of models at hand and the system of infinite-dimensional hard spheres, when the limits of interaction steepness and space dimension are both taken to infinity in a particularly described fashion.

Christos N. Likos; Bianca M. Mladek; Dieter Gottwald; Gerhard Kahl

2007-02-22T23:59:59.000Z

306

THE STELLAR NUMBER DENSITY DISTRIBUTION IN THE LOCAL SOLAR NEIGHBORHOOD IS NORTH-SOUTH ASYMMETRIC  

SciTech Connect

We study the number density distribution of a sample of K and M dwarf stars, matched north and south of the Galactic plane within a distance of 2 kpc from the Sun, using observations from the Ninth Data Release of the Sloan Digital Sky Survey. We determine distances using the photometric parallax method, and in this context systematic effects exist which could potentially impact the determination of the number density profile with height from the Galactic planeand ultimately affect a number density north-south asymmetry. They include: (1) the calibration of the various photometric parallax relations, (2) the ability to separate dwarfs from giants in our sample, (3) the role of stellar population differences such as age and metallicity, (4) the ability to determine the offset of the Sun from the Galactic plane, and (5) the correction for reddening from dust in the Galactic plane, though our stars are at high Galactic latitudes. We find the various analyzed systematic effects to have a negligible impact on our observed asymmetry, and using a new and larger sample of stars we confirm and refine the earlier discovery of Widrow et al. of a significant Galactic north-south asymmetry in the stellar number density distribution.

Yanny, Brian [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Gardner, Susan [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 (United States)

2013-11-10T23:59:59.000Z

307

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

E-Print Network (OSTI)

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

Boyer, Edmond

308

Synconset Waves and Chains: Spiking Onsets in Synchronous Populations Predict and Are Predicted by  

E-Print Network (OSTI)

Synconset Waves and Chains: Spiking Onsets in Synchronous Populations Predict and Are Predicted Synfire waves are propagating spike packets in synfire chains, which are feedforward chains embedded in random networks. Although synfire waves have proved to be effective quantification for network activity

Narayanan, Rishikesh

309

Impacts of Climate Change and Population Growth on Water Stress Becky Witte  

E-Print Network (OSTI)

Impacts of Climate Change and Population Growth on Water Stress by Becky Witte Master's Student shift toward urban areas, current water and wastewater treatment systems may not be adequate to address climate change, energy consumption, pollution, and impacts of human activities on ecosystems. Addressing

Fay, Noah

310

Case history of population change in a `bacillus thuringiensis`-treated versus an untreated outbreak of the western spruce budworm. Forest Service research note  

SciTech Connect

Larval densities of the western spruce budworm (Choristoneura occidentalis Freeman) were monitored for 12 years (1984-95) on permanent sample plots in northeastern Oregon. The time series spanned a period of general budworm infestations when populations increased rapidly from low densities, plateaued for a time at high-outbreak densities, and then declind suddenly. Midway through the period (1988), an area with half of the sample plots was sprayed with the microbial insecticide Bacillus thuringiensis (B.t.) in an operational suppression project. The other sample plots were part of an untreated area. In the treated area, B.t. spray reduced numbers of larvae by more than 90 percent; however, populations returned to an outbreak density within 3 years. In the untreated area, populations remained at outbreak densities and continued to fluctuate due to natural feedback processes. Natural decline of the population (1992-95) in the monitored area was largely unexplained and coincided with an overall collapse of the budworm outbreak in the Blue Mountains.

Mason, R.R.; Paul, H.G.

1996-09-01T23:59:59.000Z

311

THE RESONANT TRANS-NEPTUNIAN POPULATIONS  

SciTech Connect

The trans-Neptunian objects (TNOs) trapped in mean-motion resonances with Neptune were likely emplaced there during planet migration late in the giant-planet formation process. We perform detailed modeling of the resonant objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to provide population estimates and, for some resonances, constrain the complex internal orbital element distribution. Detection biases play a critical role because phase relationships with Neptune make object discovery more likely at certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3, 7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections, along with our upper limit on 1:1 Neptune Trojans (which is consistent with their small population estimated elsewhere). For the plutinos (TNOs in the 3:2 resonance) we refine the orbital element distribution given by Kavelaars et al. in 2009 and show that steep H-magnitude distributions (N(H){proportional_to}10{sup {alpha}H}, with {alpha} = 0.8-0.9) are favored in the range H{sub g} = 8-9, and confirm that this resonance does not share the inclination distribution of the classical Kuiper Belt. We give the first population estimate for the 5:2 resonance and find that, to within the uncertainties, the population is equal to that of the 3:2 ({approx_equal}13,000 TNOs with H{sub g} < 9.16), whereas the 2:1 population is smaller by a factor of 3-4 compared to the other two resonances. We also measure significant populations inhabiting the 4:3, 5:3, 7:3, 5:4, 7:4, 3:1, and 5:1 resonances, with H{sub g} < 9.16 (D > 100 km) populations in the thousands. We compare our intrinsic population and orbital element distributions with several published models of resonant-TNO production; the most striking discrepancy is that resonances beyond the 2:1 are in reality more heavily populated than in published models.

Gladman, B.; Lawler, S. M.; Van Laerhoven, C. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Petit, J.-M.; Rousselot, P. [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Kavelaars, J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jones, R. L. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Parker, J. Wm.; Bieryla, A. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Nicholson, P. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-07-15T23:59:59.000Z

312

An analysis of numerical trends in African elephant populations.  

E-Print Network (OSTI)

?? The elephant debate deals largely with population size, how elephant numbers change over time, how they may affect vegetation, and how their populations should (more)

Junker, Jessica

2009-01-01T23:59:59.000Z

313

A multi-population genetic algorithm for a constrained two ...  

E-Print Network (OSTI)

tree search algorithm for solving the d-dimensional knapsack problem. ...... PH A population heuristic, proposed by Beasley (2004), where a population of.

2008-12-10T23:59:59.000Z

314

Population balance for CFBFGD systems  

Science Journals Connector (OSTI)

Abstract Population balance is the basis of stable and effective operation of circulating fluidized bed flue gas desulfurization systems (CFBFGD systems). The population balance model parameters were calibrated by comparing the calculated results for a CFBFGD system with experimental data from a bench-scale CFBFGD system. The relative error was less than 5.1%. The influences of the model parameters, reactor structures, operating conditions, and adhesive carrier particles on the population balance of the CFBFGD system were then analyzed using the calibrated population balance model. The results indicated that particle segregation and the superficial gas velocity strongly influenced the particle size distribution. The cyclone separation efficiency and the selected particle draining coefficient also impacted the particle size distribution and the bottom ash ratio. The calcium to sulfur ratio and the bed temperature mainly influenced the bottom ash ratio and the desulfurization efficiency of the system. The anti-abrasion characteristics of the rapidly hydrated sorbent influenced the particle size distribution, the bottom ash ratio, and the desulfurization efficiency of the system. The population balance in the CFBFGD system was more easily achieved when circulating ash from a CFB boiler was used as adhesive carrier particles instead of coal fly ash. This research provides guidance for stable, effective operation of CFBFGD systems to promote industrial applications of CFBFGD technology.

Changfu You; Yuan Li

2013-01-01T23:59:59.000Z

315

Active Hydrogen  

Science Journals Connector (OSTI)

Dry hydrogen can be activated in an electric discharge if the pressure and voltage are carefully regulated. Active hydrogen reduces metallic sulphides whose heat of formation is 22 000 cal. or less. The active gas is decomposed by 3 cm of well packed glass wool. A quantitative method is given for the determination of active hydrogen. Less of the active gas is formed in a tube coated with stearic acid or phosphoric acid than when no coating is employed. The decay reaction was found to follow the expression for a unimolecular reaction. The rate of decay appears to be independent of the wall surface. The period of half?life at room temperature and 40 mm pressure is 0.2 sec. approximately. The energy of formation of active hydrogen is approximately 18 000 cal. The energy of activation for the decay of the active constituent is approximately 17 800 cal. The properties of active hydrogen are considered in relation to the properties predicted for H3.

A. C. Grubb; A. B. Van Cleave

1935-01-01T23:59:59.000Z

316

Microgrid Activities  

Energy.gov (U.S. Department of Energy (DOE))

The Energy Department has a comprehensive portfolio of activities that focuses on the development and implementation of microgrids to further improve reliability and resiliency of the grid, help...

317

Landau's necessary density conditions for LCA groups  

E-Print Network (OSTI)

H. Landau's necessary density conditions for sampling and interpolation may be viewed as a general principle resting on a basic fact of Fourier analysis: The complex exponentials $e^{i kx}$ ($k$ in $\\mathbb{Z}$) constitute an orthogonal basis for $L^2([-\\pi,\\pi])$. The present paper extends Landau's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics of Fourier analysis. The technicalities--in either case of an operator theoretic nature--are however quite different. We will base our proofs on the comparison principle of J. Ramanathan and T. Steger.

Grchenig, K; Seip, K

2008-01-01T23:59:59.000Z

318

Nuclear Energy Density Optimization: UNEDF2  

E-Print Network (OSTI)

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.

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

2014-01-01T23:59:59.000Z

319

Nuclear Energy Density Optimization: UNEDF2  

E-Print Network (OSTI)

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.

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

320

Symmetry energy in nuclear density functional theory  

E-Print Network (OSTI)

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.

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

2013-07-22T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Population inversion in Landau-quantized graphene  

E-Print Network (OSTI)

Landau level lasers have the advantage of tunability of the laser frequency by means of the external magnetic field. The crucial prerequisite of such a laser is a population inversion between optically coupled Landau levels. Efficient carrier-carrier and carrier-phonon scattering generally suppresses this effect in conventional materials. Based on microscopic calculations, we predict for the first time the occurrence of a long-lived population inversion in Landau-quantized graphene and reveal the underlying many-particle mechanisms. To guide the experimental demonstration, we present optimal conditions for the observation of a maximal population inversion in terms of experimentally accessible parameters, such as the strength of the magnetic field, pump fluence, temperature, and doping. We reveal that in addition to the tunability of the Landau-level laser frequency, also the polarization of the emitted light can be tuned via gate voltage controlling the doping of the sample.

Wendler, Florian

2014-01-01T23:59:59.000Z

322

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

SciTech Connect

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.

Stark, Eric J.

2008-12-18T23:59:59.000Z

323

Population distributions in Li vapor excited by a photoionization electron source  

Science Journals Connector (OSTI)

A detailed theoretical and experimental investigation is presented of the excited-level population distribution in a Li-Ne vapor under excitation by a photoionization electron source. This source produces a subnanosecond burst of hot (Te?20 eV) electrons with a peak density in excess of 51015 cm-3. The electrons are generated as a result of photoionization of Ne atoms by x rays emitted from a plasma produced by a 100-mJ laser pulse of 600 ps duration. Measurements of Li(1s22p)-atom density, and of electron density, have been performed with subnanosecond time resolution under various conditions of excitation. A comprehensive rate-equation model is described and its predictions are seen to be in good agreement with experiment. It is shown that the population distribution in the Li-Ne vapor is strongly influenced by recombination. Under the conditions of these experiments, rates for this process as high as 3109 s-1 were observed.

R. G. Caro and J. C. Wang

1986-04-01T23:59:59.000Z

324

STAR CLUSTER POPULATIONS IN THE OUTER DISKS OF NEARBY GALAXIES  

SciTech Connect

We present a Large Binocular Telescope imaging study that characterizes the star cluster component of nearby galaxy outer disks (beyond the optical radius R{sub 25}). Expanding on the pilot project of Herbert-Fort et al., we present deep ({approx}27.5 mag V-band point-source limiting magnitude) U- and V-band imaging of six galaxies: IC 4182, NGC 3351, NGC 4736, NGC 4826, NGC 5474, and NGC 6503. We find that the outer disk of each galaxy is populated with marginally resolved star clusters with masses {approx}10{sup 3} M{sub Sun} and ages up to {approx}1 Gyr (masses and ages are limited by the depth of our imaging and uncertainties are large given how photometry can be strongly affected by the presence or absence of a few stars in such low-mass systems), and that they are typically found out to at least 2 R{sub 25} but sometimes as far as 3-4 R{sub 25}-even beyond the apparent H I disk. The mean rate of cluster formation for 1 R{sub 25} {<=} R {<=} 1.5 R{sub 25} is at least one every {approx}2.5 Myr and the clusters are spatially correlated with the H I, most strongly with higher density gas near the periphery of the optical disk and with lower density neutral gas at the H I disk periphery. We hypothesize that the clusters near the edge of the optical disk are formed in the extension of spiral structure from the inner disk and are a fairly consistent phenomenon and that the clusters formed at the periphery of the H I disk are the result of accretion episodes.

Herbert-Fort, Stephane; Zaritsky, Dennis [Department of Astronomy/Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States); Moustakas, John [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States); Di Paola, Andrea [INAF, Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy); Pogge, Richard W. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210-1173 (United States); Ragazzoni, Roberto, E-mail: s.herbertfort@gmail.com, E-mail: dennis.zaritsky@gmail.com [INAF, Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, I-35122 Padova (Italy)

2012-08-01T23:59:59.000Z

325

Covariant density functional theory for antimagnetic rotation  

E-Print Network (OSTI)

Following the previous letter on the first microscopic description of the antimagnetic rotation (AMR) in 105Cd, a systematic investigation and detailed analysis for the AMR band in the frame-work of tilted axis cranking (TAC) model based on covariant density functional theory are carried out. After performing the microscopic and self-consistentTAC calculations with an given density functional, the configuration for the observed AMR band in 105Cd is obtained from the single-particle Routhians. With the configuration thus obtained, the tilt angle for a given rotational frequency is determined self-consistently by minimizing the total Routhian with respect to the tilt angle. In such a way, the energy spectrum, total angular momenta, kinetic and dynamic moments of inertia, and the B(E2) values for the AMR band in 105Cd are calculated. Good agreement with the data is found. By investigating microscopically the contributions from neutrons and protons to the total angular momentum, the "two-shears-like" mechanism in the AMR band is clearly illus-trated. Finally, the currents leading to time-odd mean fields in the Dirac equation are presented and discussed in detail. It is found that they are essentially determined by the valence particles and/or holes. Their spatial distribution and size depend onthe specific single-particle orbitals and the rotational frequency.

P. W. Zhao; J. Peng; H. Z. Liang; P. Ring; J. Meng

2012-05-04T23:59:59.000Z

326

Measurement of particulate densities in air  

Science Journals Connector (OSTI)

Clean air is one of the most important issues that govern the health of all live forms. However presently there are not many quick and simple methods for measuring impurities like particulates in air. These impurities have an enormous diversity in their physical and chemical structure. They may be unburned carbon particles from a diesel engine exhaust and chimney pollen grains in the spring air or asbestos in a factory. This paper shows that changes in the composition of the air cause a change in the speed of sound. Therefore by measuring the change in the speed of sound it is possible to monitor the density of particulates in the air. Preliminary tests are conducted on various smokeair mixtures. The results demonstrate that this methodology is very sensitive to any changes in the composition of the air. Its implementation is very simple and efficient and costs much less than the conventional method currently used in the auto industry. This technique will be used to calculate the mass density of the particulates resulting from a diesel engine and results thus obtained will be compared with those calculated using other methods.

2001-01-01T23:59:59.000Z

327

Site-Specific Velocity and Density Model for the Waste Treatment Plant, Hanford, Washington.  

SciTech Connect

This report documents the work conducted under the SBP to develop a shear wave and compressional wave velocity and density model specific to the WTP site. Section 2 provides detailed background information on the WTP site and its underlying geology as well as on the Seismic Boreholes Project activities leading up to the Vs and Vp measurements. In Section 3, methods employed and results obtained are documented for measurements of Vs and Vp velocities in basalts and interbeds. Section 4 provides details on velocity measurements in the sediments underlying the WTP. Borehole gravity measurements of density of the subsurface basalt and sediments are described in Section 5. Section 6 describes the analysis of data presented in section 3-5, and presents the overall velocity and density model for the WTP site.

Rohay, Alan C.; Brouns, Thomas M.

2007-06-27T23:59:59.000Z

328

Energy implications of an aging population  

SciTech Connect

This study provides various demographic, medical, and economic information relative to energy usage on a segment of the population, the elderly, which is growing in absolute numbers and relative population percentage. This growth is expected to continue well into the twenty-first century. The US aging population numbered 3.1 million in 1900, and by 1977 it had climbed to 23.5 million. It can be stated with reasonable certainty that this figure will rise to 31 million in the year 2000 and 43 million in the year 2020. These figures, corresponding to more than 10% of our population, are by no means insignificant. As our fossil-fuel reserves are being depleted and the cost of energy mounts, it becomes apparent that the elderly will become increasingly vulnerable to the energy crisis, primarily beause of their physical tendency to infirmity, their economic and social situation, and their susceptibility to psychological depression. This white paper concentrates on those aspects of aging and the nation's energy problem which are not usually related in our everyday consideration of these as separable problems. It seeks to identify the peculiar energy problems of the aged and to consider alternatives in the solution of these problems in light of modern technology.

Not Available

1980-08-01T23:59:59.000Z

329

Publications on Population Peer-Reviewed Articles  

E-Print Network (OSTI)

- population nexus in the East African Horn: emerging degradation trends in rangeland and pastoral livelihood zones. Global Environmental Change 23 (6), 1525-1541. Davis J., López-Carr D. (2014) Migration) initiatives work? Evidence from WWF-sponsored projects in Africa and Asia.Proceedings of the International

Lopez-Carr, David

330

The Population Status The American Alligator  

E-Print Network (OSTI)

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

Georgia, University of

331

Populations of Galaxies Building a Galaxy  

E-Print Network (OSTI)

1 Populations of Galaxies · Building a Galaxy · Stellar Luminosity Functions, Mass · Starburst galaxies, Ultraluminous Infrared Galaxies (ULIRGS) #12;2 Question: How would you build a synthetic metals. · Fill in an H-R (or color-magnitude) diagram and let it evolve. · Make a synthetic spectrum

Crenshaw, Michael

332

Population synthesis of wide binary millisecond pulsars  

Science Journals Connector (OSTI)

......from our population synthesis code are in good agreement with those...s1, respectively. In model NS2, the maximum amount of mass...using a rapid binary evolution code based on the analytical approximation...adopted in our binary evolution code. We assume mass transfer to......

B. Willems; U. Kolb

2002-12-11T23:59:59.000Z

333

PROSPECTIVE POPULATION OF THE UNITED STATES  

Science Journals Connector (OSTI)

...States are vast, while the forests are renewable and the farms susceptible of large increase...Saxony (778) and half that of (settled) Egypt (931). The 200, -000,000 for the...Saxony and oinly about one third that of Egypt. The rate of increase in population to...

W J MCGEE

1911-10-06T23:59:59.000Z

334

Constrained Density-Functional Theory--Configuration Interaction  

E-Print Network (OSTI)

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 ...

Kaduk, Benjamin James

2012-01-01T23:59:59.000Z

335

Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process  

E-Print Network (OSTI)

Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process J. Z. Lu,1 Q. Wu,1 I. I parameters for the wood-fiber/high-density-polyethylene blends at 60 rpm were a temperature of 180°C

336

Density scaling and anisotropy in supersonic MHD turbulence  

E-Print Network (OSTI)

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which contrast increases with the Mach number. At 10 Machs densities of some clumps are three orders of magnitude higher than the mean density. These clumps give rise to flat and approximately isotropic density spectrum corresponding to the random distribution of clumps in space. We claim that the clumps originate from our random, isotropic turbulence driving. When the contribution from those clumps is suppressed by studying logarithm of density, the density statistics exhibit scale-dependent anisotropy consistent with the models where density structures arise from shearing by Alfv\\'en waves. It is noteworthy that originally such models were advocated for the case of low-Mach, nearly incompressible turbulence.

A. Beresnyak; A. Lazarian; J. Cho

2005-02-25T23:59:59.000Z

337

High density Ru nanocrystal deposition for nonvolatile memory applications  

E-Print Network (OSTI)

High density Ru nanocrystal deposition for nonvolatile memory applications Damon B. Farmer School density optimizes the charge storing capability of the floating layer, while a high degree of size

338

Density content of nuclear symmetry energy from nuclear observables  

Science Journals Connector (OSTI)

The nuclear symmetry energy at a given density measures the energy transferred in converting symmetric nuclear matter into the pure neutron matter. The density content of nuclear symmetry energy remains poorly co...

B K AGRAWAL

2014-11-01T23:59:59.000Z

339

Neutron scattering study of human serum low density lipoprotein  

Science Journals Connector (OSTI)

Neutron scattering study of human serum low density...human serum have been determined by neutron scattering. From measurements in various H2O...protein emerging from the lipid core. Neutron scattering study of human serum low density...

H B Stuhrmann; A Tardieu; L Mateu; C Sardet; V Luzzati; L Aggerbeck; A M Scanu

1975-01-01T23:59:59.000Z

340

MULTIWAVELENGTH CONSTRAINTS ON PULSAR POPULATIONS IN THE GALACTIC CENTER  

SciTech Connect

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*.

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

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

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

SciTech Connect

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.

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

1996-01-01T23:59:59.000Z

342

Energy density fluctuations in early universe  

SciTech Connect

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.

Guardo, G. L.; Ruggieri, M. [Department of Physics and Astronomy, University of Catania, Catania (Italy); Greco, V. [Department of Physics and Astronomy, University of Catania, Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy)

2014-05-09T23:59:59.000Z

343

Fabrication of nanoscale charge density wave systems  

Science Journals Connector (OSTI)

Nanoscale charge density wave systems of quasi-one-dimensional o ? TaS 3 crystals were fabricated.Goldelectrodes 400 nm wide were made by standard lift-off technique on o ? TaS 3 nanocrystals prepared by deposition on silicon substrates. Interface resistance was higher than 100 G ? just after evaporation and were significantly reduced by electron-beam irradiation. The electrodes were tested down to 80 mK and were found quite durable for cryogenic measurement. The temperature dependence of the resistance of the nanocrystal was represented as the variable-range-hopping-type conduction with one dimension over the wide range of temperature from 4.2 to 100 K. This behavior was different from that of conventional bulk samples.

Katsuhiko Inagaki; Takeshi Toshima; Satoshi Tanda; Kazuhiko Yamaya; Shinya Uji

2005-01-01T23:59:59.000Z

344

Energy density fluctuations in Early Universe  

E-Print Network (OSTI)

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.

Guardo, G L; Ruggieri, M

2014-01-01T23:59:59.000Z

345

DENSITY ENHANCEMENTS AND VOIDS FOLLOWING PATCHY RECONNECTION  

SciTech Connect

We show, through a simple patchy reconnection model, that retracting reconnected flux tubes may present elongated regions relatively devoid of plasma, as well as long lasting, dense central hot regions. Reconnection is assumed to happen in a small patch across a Syrovatskii (non-uniform) current sheet (CS) with skewed magnetic fields. The background magnetic pressure has its maximum at the center of the CS plane and decreases toward its edges. The reconnection patch creates two V-shaped reconnected tubes that shorten as they retract in opposite directions, due to magnetic tension. One of them moves upward toward the top edge of the CS, and the other one moves downward toward the top of the underlying arcade. Rotational discontinuities (RDs) propagate along the legs of the tubes and generate parallel supersonic flows that collide at the center of the tube. There, gas-dynamic shocks that compress and heat the plasma are launched outwardly. The descending tube moves through the bottom part of the CS where it expands laterally in response to the decreasing background magnetic pressure. This effect may decrease plasma density by 30%-50% of background levels. This tube will arrive at the top of the arcade that will slow it to a stop. Here, the perpendicular dynamics is halted, but the parallel dynamics continues along its legs; the RDs are shut down, and the gas is rarified to even lower densities. The hot post-shock regions continue evolving, determining a long lasting hot region on top of the arcade. We provide an observational method based on total emission measure and mean temperature that indicates where in the CS the tube has been reconnected.

Guidoni, S. E.; Longcope, D. W., E-mail: guidoni@physics.montana.edu [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States)

2011-04-01T23:59:59.000Z

346

Superfluid Local Density Approximation: A Density Functional Theory Approach to the Nuclear Pairing Problem  

E-Print Network (OSTI)

I describe the foundation of a Density Functional Theory approach to include pairing correlations, which was applied to a variety of systems ranging from dilute fermions, to neutron stars and finite nuclei. Ground state properties as well as properties of excited states and time-dependent phenomena can be achieved in this manner within a formalism based on microscopic input.

Aurel Bulgac

2012-04-10T23:59:59.000Z

347

Density-Enthalpy Phase Diagram 0D Boiler Simulation  

E-Print Network (OSTI)

Density-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;Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research Goal

Vuik, Kees

348

HIGHLIGHT OF THE MONTH Orbital Functionals in Density Functional Theory  

E-Print Network (OSTI)

HIGHLIGHT OF THE MONTH Orbital Functionals in Density Functional Theory: The Optimized E#11;ectiveurzburg, Am Hubland, D-97074 Wurzburg, Germany The success of density functional theory hinges the development of modern density functional theory. In present-day language, the exact OEP should be called

Gross, E.K.U.

349

Electronic excitations in complex systems: beyond density functional theory  

E-Print Network (OSTI)

Electronic excitations in complex systems: beyond density functional theory for real materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3 Time-dependent density functional theory 19 3.1 The Runge-Gross theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 Model kernels from many-body perturbation theory 29 4.1 Time-dependent density functional theory

Botti, Silvana

350

A Guided Tour of TimeDependent Density Functional Theory  

E-Print Network (OSTI)

A Guided Tour of Time­Dependent Density Functional Theory Kieron Burke 1 and E.K.U. Gross 2 1 outlook. 1 Introduction and User's Guide Density functional theory is the study of the one in density functional theory, driven largely by its applications in quantum chemistry[3]. This is due

Gross, E.K.U.

351

EFFECTIVE MAXWELL EQUATIONS FROM TIME-DEPENDENT DENSITY FUNCTIONAL THEORY  

E-Print Network (OSTI)

EFFECTIVE MAXWELL EQUATIONS FROM TIME-DEPENDENT DENSITY FUNCTIONAL THEORY WEINAN E, JIANFENG LU and magnetic fields are derived starting from time-dependent density functional theory. Effective permittivity with the density functional theory [2­4] instead of the many-body Schr¨odinger or Dirac equations. This is because

Bigelow, Stephen

352

Density Functional Theory applied to the solid state...  

E-Print Network (OSTI)

Density Functional Theory applied to the solid state... An introduction to VASP Jeremie Zaffran 2nd Marom (PhD) #12;Contents I- DFT and its functionals A. On the density functional theory... B #12;I- DFT and its functionals #12;I-DFT and its functionals A- On the density functional theory Why

Adler, Joan

353

Benchmark density functional theory calculations for nanoscale conductance  

E-Print Network (OSTI)

Benchmark density functional theory calculations for nanoscale conductance M. Strange,a I. S. The transmission functions are calculated using two different density functional theory methods, namely state density functional theory DFT . The resulting NEGF- DFT formalism provides a numerically efficient

Thygesen, Kristian

354

1 Density Functional Theory for Emergents Robert O. Jones  

E-Print Network (OSTI)

1 Density Functional Theory for Emergents Robert O. Jones Peter-Gr¨unberg-Institut PGI-1 and German the widespread use of density functional (DF) theory in materials science and chemistry and the physical insight as basic variable 3 3 An "approximate practical method" 5 4 Density functional formalism 7 4.1 Single

355

THE MANY-ELECTRON ENERGY IN DENSITY FUNCTIONAL THEORY  

E-Print Network (OSTI)

THE MANY-ELECTRON ENERGY IN DENSITY FUNCTIONAL THEORY From Exchange-Correlation Functional Design to the configuration of its electrons. Computer programs based on density functional theory (DFT) can calculate applicable within the field of computational density functional theory. Sammanfattning Att förutsäga

Armiento, Rickard

356

RELATIVISTIC DENSITY FUNCTIONAL THEORY: FOUNDATIONS AND BASIC FORMALISM  

E-Print Network (OSTI)

1 Chapter 10 RELATIVISTIC DENSITY FUNCTIONAL THEORY: FOUNDATIONS AND BASIC FORMALISM E. Engela a An overview of relativistic density functional theory (RDFT) is presented with special emphasis on its field-Cluster schemes in recent years density functional theory (DFT) still represents the method of choice

Engel, Eberhard

357

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 in the future study. Keywords Bamboo Á High density polyethylene Á Coupling treatment Á Nanoclay Introduction

358

Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities  

DOE Patents (OSTI)

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.

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

2008-08-05T23:59:59.000Z

359

Density of the Values Set of the Tau Function  

E-Print Network (OSTI)

It is shown that the density of the values set {Tau(n): n > x/log x. The currently known density is #{Tau(n) : n > x^(1/2+o(1)), and the expected density is #{Tau(n) : n 2, which arises as a singular case of this analysis, is discussed within.

N. A. Carella

2014-04-10T23:59:59.000Z

360

Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore  

SciTech Connect

The density fluctuations, modified by Lower Hybrid Wave (LHW), is analyzed in Tore Supra with reference to the injected LHW power, density and the gap between LCFS (Last Closed Flux Surface) and the PAM (passive-active-multijunction) launcher. The density fluctuations are measured with RF probes installed at the PAM launcher front. A density scan at nominal toroidal field (3.8 T) shows that the fluctuations rate stays nearly constant ({approx}50%) for <3.5x10{sup 19}m{sup -3} and with LHW power up to 2MW. However, when increasing the density above <{approx}4.2x10{sup 19}m{sup -3}, using strong gas puffing, the fluctuation rate increases to >70% and is characterized by strong negative spikes, with typical frequency >100kHz. These are most likely originating from acceleration of electrons in the LHW near field due to parasitic absorption, as evidenced on the IR images, showing hot spots on the side limiters.

Oosako, T.; Ekedahl, A.; Goniche, M.; Achard, J.; Decker, J.; Peysson, Y. [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)

2011-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Density functional theory in the solid state  

Science Journals Connector (OSTI)

...active area of research in Computer Science, but its impact has...to make full use of exascale computers and beyond. An alternative...iterative matrix methods, both the computer memory and time required for...consortium and funded by EPSRC grant no. EP/K013564/1. Figure...

2014-01-01T23:59:59.000Z

362

E-Print Network 3.0 - atomic oxygen densities Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

densities Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen densities...

363

E-Print Network 3.0 - atomic oxygen density Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

density Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen density...

364

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

E-Print Network (OSTI)

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...

Vaidyanathan, Vidya

2009-05-15T23:59:59.000Z

365

Galaxy density profiles and shapes -- II. selection biases in strong lensing surveys  

E-Print Network (OSTI)

[Abridged] Many current and future astronomical surveys will rely on samples of strong gravitational lens systems to draw conclusions about galaxy mass distributions. We use a new strong lensing pipeline (presented in Paper I of this series) to explore selection biases that may cause the population of strong lensing systems to differ from the general galaxy population. Our focus is on point-source lensing by early-type galaxies with two mass components (stellar and dark matter) that have a variety of density profiles and shapes motivated by observational and theoretical studies of galaxy properties. We seek not only to quantify but also to understand the physics behind selection biases related to: galaxy mass, orientation and shape; dark matter profile parameters such as inner slope and concentration; and adiabatic contraction. We study how all of these properties affect the lensing Einstein radius, total cross-section, quad/double ratio, and image separation distribution. We find significant (factors of several) selection biases with mass; orientation, for a given galaxy shape at fixed mass; cusped dark matter profile inner slope and concentration; concentration of the stellar and dark matter deprojected Sersic models. Interestingly, the intrinsic shape of a galaxy does not strongly influence its lensing cross-section when we average over viewing angles. Our results are an important first step towards understanding how strong lens systems relate to the general galaxy population.

Rachel Mandelbaum; Glenn van de Ven; Charles R. Keeton

2009-06-18T23:59:59.000Z

366

Dynamics of ion acoustic double layers in a magnetized two-population electrons plasma  

SciTech Connect

The obliquely propagating ion acoustic (IA) double-layers are investigated in a magnetized two population electron plasmas. The extended Kortewegde Vries equation is derived by using the reductive perturbation technique. The effect of obliqueness (l{sub z}) and magnitude of the external magnetic field (?{sub ci}), as well as the electron number density (?) on the double-layer profile, is studied, and then the ranges of parameters for which the double-layers exist are investigated in detail. We found that the combined effects of l{sub z}, ?{sub ci}, and ? significantly modify the basic properties (viz. amplitude and width) of the IA double-layers.

Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of)

2013-10-15T23:59:59.000Z

367

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

WASHINGTON WASHINGTON February 11, 1994 MEMORANDUM FOR THE HEADS OF ALL DEPARTMENTS AND AGENCIES SUBJECT: Executive Order on Federal Actions to Address Environmental Justice in Minority Populations and Low- Income Populations Today I have issued an Executive Order on Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations. That order is designed to focus Federal attention on the environmental and human health conditions in minority communities and low-income communities with the goal of achieving environmental justice. That order is also intended to promote nondiscrimination in Federal programs substantially affecting human health and the environment, and to provide minority communities and low-income communities access to public

368

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

SciTech Connect

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.

GJ Schuster, FA Simonen, SR Doctor

2008-04-01T23:59:59.000Z

369

Active Seismic Techniques | Open Energy Information  

Open Energy Info (EERE)

Active Seismic Techniques Active Seismic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Active Seismic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Seismic Techniques Parent Exploration Technique: Seismic Techniques Information Provided by Technique Lithology: Rock unit density influences elastic wave velocities. Stratigraphic/Structural: Structural geology- faults, folds, grabens, horst blocks, sedimentary layering, discontinuities, etc. Hydrological: Combining compressional and shear wave results can indicate the presence of fluid saturation in the formation. Thermal: High temperatures and pressure impact the compressional and shear wave velocities.

370

Nonperturbative Coherent Population Trapping: An Analytic Model  

Science Journals Connector (OSTI)

Coherent population trapping is shown to occur in a driven symmetric double-well potential in the strong-field regime. The system parameters have been chosen to reproduce the 0-?3+ transition of the inversion mode of the ammonia molecule. For a molecule initially prepared in its lower doublet we find that, under certain circumstances, the 3+ level remains unpopulated, and this occurs in spite of the fact that the laser field is resonant with the 0-?3+ transition and intense enough so as to strongly mix the 0+ and 0- ground states. This counterintuitive result constitutes a coherent population trapping phenomenon of nonperturbative origin which cannot be accounted for with the usual models.

V. Delgado and J. M. Gomez Llorente

2002-01-23T23:59:59.000Z

371

DENSITY AND ECCENTRICITY OF KEPLER PLANETS  

SciTech Connect

We analyze the transit timing variations (TTV) obtained by the Kepler mission for 22 sub-Jovian planet pairs (19 published, 3 new) that lie close to mean motion resonances. We find that the TTV phases for most of these pairs lie close to zero, consistent with an eccentricity distribution that has a very low root-mean-squared value of e {approx} 0.01; but about a quarter of the pairs possess much higher eccentricities, up to e {approx} 0.1-0.4. For the low-eccentricity pairs, we are able to statistically remove the effect of eccentricity to obtain planet masses from TTV data. These masses, together with those measured by radial velocity, yield a best-fit mass-radius relation M {approx} 3 M{sub Circled-Plus }(R/R{sub Circled-Plus }). This corresponds to a constant surface escape velocity of {approx}20 km s{sup -1}. We separate the planets into two distinct groups: ''mid-sized'' (those greater than 3 R{sub Circled-Plus }) and 'compact' (those smaller). All mid-sized planets are found to be less dense than water and therefore must contain extensive H/He envelopes that are comparable in mass to that of their cores. We argue that these planets have been significantly sculpted by photoevaporation. Surprisingly, mid-sized planets, a minority among Kepler candidates, are discovered exclusively around stars more massive than 0.8 M{sub Sun }. The compact planets, on the other hand, are often denser than water. Combining our density measurements with those from radial velocity studies, we find that hotter compact planets tend to be denser, with the hottest ones reaching rock density. Moreover, hotter planets tend to be smaller in size. These results can be explained if the compact planets are made of rocky cores overlaid with a small amount of hydrogen, {<=}1% in mass, with water contributing little to their masses or sizes. Photoevaporation has exposed bare rocky cores in cases of the hottest planets. Our conclusion that these planets are likely not water worlds contrasts with some previous studies. While mid-sized planets most likely accreted their hydrogen envelope from the proto-planetary disks, compact planets could have obtained theirs via either accretion or outgassing. The presence of the two distinct classes suggests that 3 R{sub Circled-Plus} could be identified as the dividing line between 'hot Neptunes' and 'super-Earths'.

Wu Yanqin [Department of Astronomy and Astrophysics, University of Toronto, ON M5S 3H4 (Canada); Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

2013-07-20T23:59:59.000Z

372

Population dynamics of the Concho water snake  

E-Print Network (OSTI)

the upper Colorado and Concho river systems of central Texas. It is 1 of 2 subspecies, the other being the Brazos water snake (Nerodia harteri harteri) which occurs in the Brazos river system of north-central Texas, Together they comprise the only species..., reproductive potential, mortality, and movements. williams predicted that habitat degradation resulting from the creation of Spence Reservoir, 2 km above his study site, would be detrimental to the Concho water snake population. Since the impoundment...

Mueller, James Michael

1990-01-01T23:59:59.000Z

373

ANL Activities  

NLE Websites -- All DOE Office Websites (Extended Search)

Activities of the DOD Activities of the DOD Project Office focus today on the Navy's Free Electron Laser Program Argonne Accelerator Institute Meeting June 16, 2009 2 Several Beam Activities and Interests Ongoing  Terahertz sources and applications  Navy Free Electron Laser (Focus area today)  Free Electron Laser Applications  Electromagnetic Interference Technology Review Committees  Novel Fiber Optic Materials with Army Research Lab  Optical Diagnostics for next-generation light sources  Neutron detection schemes  NATO Sensors and Electronics Panel, international field tests of directed energy source applications  Controls  Radiation Oncology 3 Background, Naval Directed Energy History The U.S Navy has been investigating utility of lasers since the 1960's and the

374

Public Activities  

NLE Websites -- All DOE Office Websites (Extended Search)

publicactivities_header.jpg publicactivities_header.jpg Public Activities Citizens are encouraged to learn about the Department of Energy's programs through a variety of activities that are open to the public. Our goal is to educate citizens and seek their meaningful involvement. If you are visiting the area, the American Museum of Science and Energy in Oak Ridge is the best starting point for exhibits and information about DOE programs in science, environmental management, nuclear fuel supply, and national security. Tours are conducted of the Oak Ridge National Laboratory, Y-12 National Security Complex and East Tennessee Technology Park during the summer months departing from the Museum. For those with more specific interests in our programs, each month we publish a calendar of public involvement activities, which identifies announcements, comment periods and public meetings of potential interest. Our Environmental Management Program has a Site Specific Advisory Board composed of area citizens who meet the second Wednesday of each month.

375

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network (OSTI)

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Zhang, Yingxun; Li, Zhuxia; Danielewicz, P; Lynch, W G; Lu, Xiaohua

2009-01-01T23:59:59.000Z

376

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network (OSTI)

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Yingxun Zhang; M. B. Tsang; Zhuxia Li; P. Danielewicz; W. G. Lynch; Xiaohua Lu

2009-11-09T23:59:59.000Z

377

Building a Universal Nuclear Energy Density Functional  

SciTech Connect

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.

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

378

Design of maximum density aggregate grading  

Science Journals Connector (OSTI)

An aggregate grading that yields maximum solid density and maximum particle interlock is highly desirable for both bound mixtures, such as asphalt concrete and plain and reinforced concrete, and for unbound mixtures such as those used in base courses. Maximum particle interlock leads to high strength. Whereas minimum voids in a certain material composition is conducive to high strength and low compression. Aggregate grading may be obtained, for instance, from the ASTM, which is based on experience or may be designed according to Lees method. In the present work five different types of aggregates were used, each with a variety of chosen grading. It was found that Lees method produced the lowest porosity of all types of aggregates as well as for the various employed gradings. Lees rational method of aggregate grading, however, is a very lengthy and time-consuming procedure. Therefore, programming of Lees method is an essential step to make such an excellent method available to practicing engineers. A program named ratmix was developed and has incorporated 58 design graphs of the Lees method. ratmix is a comprehensive program for Lees rational method; it conducts interpolation for intermediate points within the design graphs as well as between graphs of different properties.

Yahia A Abdel-Jawad; Waddah Salman Abdullah

2002-01-01T23:59:59.000Z

379

wind power density | OpenEI  

Open Energy Info (EERE)

density density Dataset Summary Description This dataset was developed by the National Renewable Energy Laboratory (NREL) for the U.S. Source National Renewable Energy Lab (NREL) Date Released Unknown Date Updated Unknown Keywords afghanistan dataset GIS Wind Power wind power density Data application/zip icon Wind Power Density at 50-m Above Ground Level GIS Data (zip, 1.4 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Other or unspecified, see optional comment below Comment DISCLAIMER NOTICE This GIS data was developed by the National Renewable Energy Laboratory ("NREL"), which is operated by the Alliance for Sustainable Energy, LLC for the U.S. Department of Energy ("DOE"). The user is granted the right, without any fee or cost, to use, copy, modify, alter, enhance and distribute this data for any purpose whatsoever, provided that this entire notice appears in all copies of the data. Further, the user of this data agrees to credit NREL in any publications or software that incorporate or use the data. Access to and use of the GIS data shall further impose the following obligations on the User. The names DOE/NREL may not be used in any advertising or publicity to endorse or promote any product or commercial entity using or incorporating the GIS data unless specific written authorization is obtained from DOE/NREL. The User also understands that DOE/NREL shall not be obligated to provide updates, support, consulting, training or assistance of any kind whatsoever with regard to the use of the GIS data. THE GIS DATA IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DOE/NREL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS, WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE ACCESS OR USE OF THE GIS DATA. The User acknowledges that access to the GIS data is subject to U.S. Export laws and regulations and any use or transfer of the GIS data must be authorized under those regulations. The User shall not use, distribute, transfer, or transmit GIS data or any products incorporating the GIS data except in compliance with U.S. export regulations. If requested by DOE/NREL, the User agrees to sign written assurances and other export-related documentation as may be required to comply with U.S. export regulations. DISCLAIMER NOTICE This GIS data was developed by the National Renewable Energy Laboratory ("NREL"), which is operated by the Alliance for Sustainable Energy, LLC for the U.S. Department of Energy ("DOE"). The user is granted the right, without any fee or cost, to use, copy, modify, alter, enhance and distribute this data for any purpose whatsoever, provided that this entire notice appears in all copies of the data. Further, the user of this data agrees to credit NREL in any publications or software that incorporate or use the data. Access to and use of the GIS data shall further impose the following obligations on the User. The names DOE/NREL may not be used in any advertising or publicity to endorse or promote any product or commercial entity using or incorporating the GIS data unless specific written authorization is obtained from DOE/NREL. The User also understands that DOE/NREL shall not be obligated to provide updates, support, consulting, training or assistance of any kind whatsoever with regard to the use of the GIS data. THE GIS DATA IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DOE/NREL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS, WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE ACCESS OR USE OF THE GIS DATA. The User acknowledges that access to the GIS data is subject to U.S. Export laws and regulations and any use or transfer of the GIS data must be authorized under those regulations. The User shall not use, distribute, transfer, or transmit GIS data or any products incorporating the GIS data except in compliance with U.S. export regulations. If requested by DOE/NREL, the User agrees to sign written assurances and other export-related documentation as may be required to comply with U.S. export regulations.

380

Current density partitioning in time-dependent current density functional theory  

SciTech Connect

We adapt time-dependent current density functional theory to allow for a fragment-based solution of the many-electron problem of molecules in the presence of time-dependent electric and magnetic fields. Regarding a molecule as a set of non-interacting subsystems that individually evolve under the influence of an auxiliary external electromagnetic vector-scalar potential pair, the partition 4-potential, we show that there are one-to-one mappings between this auxiliary potential, a sharply-defined set of fragment current densities, and the total current density of the system. The partition electromagnetic (EM) 4-potential is expressed in terms of the real EM 4-potential of the system and a gluing EM 4-potential that accounts for exchange-correlation effects and mutual interaction forces between fragments that are required to yield the correct electron dynamics. We prove the zero-force theorem for the fragmented system, establish a variational formulation in terms of action functionals, and provide a simple illustration for a charged particle in a ring.

Mosquera, Martn A. [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Wasserman, Adam, E-mail: awasser@purdue.edu [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States) [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)

2014-05-14T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
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381

THE SPACE DENSITY EVOLUTION OF WET AND DRY MERGERS IN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY  

SciTech Connect

We analyze 1298 merging galaxies with redshifts up to z = 0.7 from the Canada-France-Hawaii Telescope Legacy Survey, taken from the catalog presented in the work of Bridge et al. By analyzing the internal colors of these systems, we show that the so-called wet and dry mergers evolve in different senses, and quantify the space densities of these systems. The local space density of wet mergers is essentially identical to the local space density of dry mergers. The evolution in the total merger rate is modest out to z {approx} 0.7, although the wet and dry populations have different evolutionary trends. At higher redshifts, dry mergers make a smaller contribution to the total merging galaxy population, but this is offset by a roughly equivalent increase in the contribution from wet mergers. By comparing the mass density function of early-type galaxies to the corresponding mass density function for merging systems, we show that not all the major mergers with the highest masses (M{sub stellar}>10{sup 11} M{sub sun}) will end up with the most massive early-type galaxies, unless the merging timescale is dramatically longer than that usually assumed. On the other hand, the usually assumed merging timescale of {approx}0.5-1 Gyr is quite consistent with the data if we suppose that only less massive early-type galaxies form via mergers. Since low-intermediate-mass ellipticals are 10-100 times more common than their most massive counterparts, the hierarchical explanation for the origin of early-type galaxies may be correct for the vast majority of early types, even if incorrect for the most massive ones.

Chou, Richard C. Y.; Abraham, Roberto G. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Bridge, Carrie R., E-mail: chou@astro.utoronto.ca, E-mail: abraham@astro.utoronto.ca, E-mail: bridge@astro.caltech.edu [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

2011-03-15T23:59:59.000Z

382

Wind Speed Distribution A Theoretical Approach to Probability Density Function  

Science Journals Connector (OSTI)

Provided overwhelmingly by conventional fossil fuels, global primary energy consumption has been increasing as a result of improved living standards, industrialization of developing countries, and population i...

Xianguo Li

2011-01-01T23:59:59.000Z

383

Giant otter population responses to habitat expansion and degradation induced by a mega hydroelectric dam  

Science Journals Connector (OSTI)

Abstract Large hydroelectric dams are major drivers of habitat loss and degradation in lowland Amazonia. Hydroelectric reservoirs reduce the habitat available for terrestrial species, but create new open-water and shoreline lake habitat that can potentially boost populations of aquatic and semi-aquatic species, such as the threatened giant otter (Pteronura brasiliensis). To assess the impacts of mega-dams on this apex-predator, we surveyed the giant otter population across the 443,772-hectare Balbina Hydroelectric Reservoir of central Brazilian Amazonia between 14 and 25years after this reservoir creation. We compared changes in habitat area and estimated giant otter population size between the reservoir pre- and post-filling stages. The Balbina dam created ?3525 islands and increased the open-water surface and total reservoir perimeter available to otters by a factor of 62.7 and 8.9, respectively. Some 25years after damming, however, the estimated post-filling giant otter population size was only twice greater than that estimated before filling and 4.5 times smaller than would be predicted given the total available habitat area and density of dens quantified at a neighbouring undisturbed area used as a surrogate of the pre-filling phase. The observed mismatch between the proportional increase in otter population size and the much greater newly available reservoir habitat area is likely due to low habitat quality in terms of low fish prey productivity and scarcity of suitable sites for denning and territory demarcation. This should be considered in strategic environmental impact assessments of planned hydroelectric dams and in managing existing and future hydropower development in lowland tropical forests.

Ana Filipa Palmeirim; Carlos A. Peres; Fernando C.W. Rosas

2014-01-01T23:59:59.000Z

384

Density Functional Theory Calculations of Mass Transport in UO2  

SciTech Connect

In this talk we present results of density functional theory (DFT) calculations of U, O and fission gas diffusion in UO{sub 2}. These processes all impact nuclear fuel performance. For example, the formation and retention of fission gas bubbles induce fuel swelling, which leads to mechanical interaction with the clad thereby increasing the probability for clad breach. Alternatively, fission gas can be released from the fuel to the plenum, which increases the pressure on the clad walls and decreases the gap thermal conductivity. The evolution of fuel microstructure features is strongly coupled to diffusion of U vacancies. Since both U and fission gas transport rates vary strongly with the O stoichiometry, it is also important to understand O diffusion. In order to better understand bulk Xe behavior in UO{sub 2{+-}x} we first calculate the relevant activation energies using DFT techniques. By analyzing a combination of Xe solution thermodynamics, migration barriers and the interaction of dissolved Xe atoms with U, we demonstrate that Xe diffusion predominantly occurs via a vacancy-mediated mechanism. Since Xe transport is closely related to diffusion of U vacancies, we have also studied the activation energy for this process. In order to explain the low value of 2.4 eV found for U migration from independent damage experiments (not thermal equilibrium) the presence of vacancy clusters must be included in the analysis. Next we investigate species transport on the (111) UO{sub 2} surface, which is motivated by the formation of small voids partially filled with fission gas atoms (bubbles) in UO{sub 2} under irradiation. Surface diffusion could be the rate-limiting step for diffusion of such bubbles, which is an alternative mechanism for mass transport in these materials. As expected, the activation energy for surface diffusion is significantly lower than for bulk transport. These results are further discussed in terms of engineering-scale fission gas release models. Finally, oxidation of UO{sub 2} and the importance of cluster formation for understanding thermodynamic and kinetic properties of UO{sub 2+x} are investigated.

Andersson, Anders D. [Los Alamos National Laboratory; Dorado, Boris [CEA; Uberuaga, Blas P. [Los Alamos National Laboratory; Stanek, Christopher R. [Los Alamos National Laboratory

2012-06-26T23:59:59.000Z

385

The Dark Energy Survey: Prospects for Resolved Stellar Populations  

Science Journals Connector (OSTI)

Wide angle and deep surveys, regardless of their primary purpose, always sample a large number of stars in the Galaxy and in its satellite system. Here we make a forecast of the expected stellar sample resulting from the Dark Energy Survey (DES) and the perspectives that it will open for studies of Galactic structure and resolved stellar populations in general. An estimated 1.2 ? 108 stars will be sampled in DES grizY filters in the southern equatorial hemisphere. This roughly corresponds to 20% of all DES sources. Most of these stars belong to the stellar thick disk and halo of the Galaxy. DES will probe low-mass stellar and sub-stellar objects at depths from three to eight times larger than those in the Sloan Digital Sky Survey (SDSS). The faint end of the main sequence (MS) will be densely sampled beyond 10kpc. The slope of the low mass end of the stellar initial mass function (IMF) will be constrained to within a few hundredths of dex, even in the thick disk and halo. In the sub-stellar mass regime, the IMF slope will be potentially constrained to within dlog (m)/dlog m 0.1. About 3 ? 104 brown dwarf candidates and at least 7.6 ? 105 white dwarf candidates will be selected, the latter embedded into the thick disk and halo, for future follow-up. The stellar halo flattening will also be constrained to within a few percent. DES will probe the MS of new Milky Way satellites and halo clusters for distances out to 120kpc, therefore yielding stellar surface density contrasts 1.6-1.7 times larger than those attainable with SDSS. It will also allow detection of these objects in the far reaches of the stellar halo, substantially increasing the number and quality of probes to the Galactic potential. Combined with northern samples, such as the SDSS, the DES stellar sample will yield constraints on the structure and stellar populations of Galactic components in unprecedented detail. In particular, the combined sample from both hemispheres will allow detailed studies of halo and thick disk asymmetries and triaxiality.

Bruno M. Rossetto; Baslio X. Santiago; Lo Girardi; Julio I. B. Camargo; Eduardo Balbinot; Luiz N. da Costa; Brian Yanny; Marcio A. G. Maia; Martin Makler; Ricardo L. C. Ogando; Paulo S. Pellegrini; Beatriz Ramos; Fernando de Simoni; R. Armstrong; E. Bertin; S. Desai; N. Kuropatkin; H. Lin; J. J. Mohr; D. L. Tucker

2011-01-01T23:59:59.000Z

386

Density Inhomogeneities and Electron Mobility in Supercritical Xenon  

NLE Websites -- All DOE Office Websites (Extended Search)

Density Inhomogeneities and Electron Mobility in Supercritical Xenon Density Inhomogeneities and Electron Mobility in Supercritical Xenon Richard A. Holroyd, Kengo Itoh, and Masaru Nishikawa J. Chem. Phys. 118, 706-710 (2003) [Find paper at Scitation] Abstract: The low-field mobility of electrons in supercritical Xe has been measured isothermally as a function of density above the critical temperature (289.7 K). At 293 K the mobility varies from a high of 890 cm2/Vs at 9.2 x 1021 atoms/cm3 to a minimum value of 4.6 cm2/Vs at a density of 3.5 x 1021 atoms/cm3, which is just below the critical density. The density dependence of the mobility is reasonably well predicted by the deformation potential model if the adiabatic compressibility is used to characterize the electron-medium interactions. Approximate agreement indicates that

387

Textured-surface quartz resonator fluid density and viscosity monitor  

DOE Patents (OSTI)

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.

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

388

Theoretical power density from salinity gradients using reverse electrodialysis  

Science Journals Connector (OSTI)

Reverse electrodialysis (RED) is a technology to generate power from mixing waters with different salinity. The net power density (i.e. power per membrane area) is determined by 1) the membrane potential, 2) the ohmic resistance, 3) the resistance due to changing bulk concentrations, 4) the boundary layer resistance and 5) the power required to pump the feed water. Previous power density estimations often neglected the latter three terms. This paper provides a set of analytical equations to estimate the net power density obtainable from RED stacks with spacers and RED stacks with profiled membranes. With the current technology, the obtained maximum net power density is calculated at 2.7W/m2. Higher power densities could be obtained by changing the cell design, in particular the membrane resistance and the cell length. Changing these parameters one and two orders of magnitude respectively, the calculated net power density is close to 20W/m2.

David A. Vermaas; Enver Guler; Michel Saakes; Kitty Nijmeijer

2012-01-01T23:59:59.000Z

389

The rise and fall of the Aldabran giant tortoise population  

Science Journals Connector (OSTI)

...to natural population regulatory mechanisms, exacerbated...to natural population regulatory mechanisms, exacerbated...the mid-1960s, when plans for development of Aldabra...following a strategic review of Britain's defence...the pound sterling, plans for military development...

1999-01-01T23:59:59.000Z

390

High-Precision Thermodynamics and Hagedorn Density of States  

E-Print Network (OSTI)

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.

Harvey B. Meyer

2009-05-26T23:59:59.000Z

391

Particle-Number Projection and the Density Functional Theory  

E-Print Network (OSTI)

In the framework of the Density Functional Theory for superconductors, we study the restoration of the particle number symmetry by means of the projection technique. Conceptual problems are outlined and numerical difficulties are discussed. Both are related to the fact that neither the many-body Hamiltonian nor the wave function of the system appear explicitly in the Density Functional Theory. Similar obstacles are encountered in self-consistent theories utilizing density-dependent effective interactions.

J. Dobaczewski; M. V. Stoitsov; W. Nazarewicz; P. -G. Reinhard

2007-08-03T23:59:59.000Z

392

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network (OSTI)

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Razeghizadeh, Alireza; Lavafpour, Farhad

2015-01-01T23:59:59.000Z

393

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network (OSTI)

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

2015-02-07T23:59:59.000Z

394

Observation of ionization fronts in low density foam targets  

SciTech Connect

Ionization fronts have been observed in low density chlorinated foam targets and low density foams confined in gold tubes using time resolved {ital K}-shell absorption spectroscopy. The front was driven by an intense pulse of soft x-rays produced by high power laser irradiation. The density and temperature profiles inferred from the radiographs provided detailed measurement of the conditions. The experimental data were compared to radiation hydrodynamics simulations and reasonable agreement was obtained. {copyright} {ital 1999 American Institute of Physics.}

Hoarty, D. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); [Radiation Physics Department, AWE Aldermaston, Reading, Berkshire (United Kingdom); Willi, O.; Barringer, L.; Vickers, C. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); Watt, R. [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Nazarov, W. [Chemistry Department, University of Dundee (United Kingdom)] [Chemistry Department, University of Dundee (United Kingdom)

1999-05-01T23:59:59.000Z

395

Nuclear symmetry energy at subnormal densities from measured nuclear masses  

Science Journals Connector (OSTI)

The symmetry energy coefficients for nuclei with mass number A=20250 are extracted from more than 2000 measured nuclear masses. With the semiempirical connection between the symmetry energy coefficients of finite nuclei and the nuclear symmetry energy at reference densities, we investigate the density dependence of the symmetry energy of nuclear matter at subnormal densities. The obtained results are compared with those extracted from other methods.

Min Liu; Ning Wang; Zhu-Xia Li; Feng-Shou Zhang

2010-12-13T23:59:59.000Z

396

Nuclear symmetry energy at subnormal densities from measured nuclear masses  

E-Print Network (OSTI)

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.

Min Liu; Ning Wang; Zhuxia Li; Fengshou Zhang

2010-11-17T23:59:59.000Z

397

Unambiguous exchange-correlation energy density Kieron Burke,a)  

E-Print Network (OSTI)

density approximation LDA , the conventional form is eXC unif (r) , the exchange-correlation energy the following definition of an energy density: eXC wave fn. r d3 r P r,r r r 2 r r 1 2 2 r,r s r,r r r , 2 whereUnambiguous exchange-correlation energy density Kieron Burke,a) Federico G. Cruz, and Kin-Chung Lam

Burke, Kieron

398

A Further Generalized Lagrangian Density and Its Special Cases  

E-Print Network (OSTI)

By summarizing and extending the Lagrangian densities of the general relativity and the Kibble's gauge theory of gravitation,a further generalized Lagrangian density for a gravitational system is obtained and analyzed in greater detail, which can be used for studying more extensive range of gravitation. Many special cases can be derived from this generalized Lagrangian density, their general characters and peculiarities will be briefly described.

Fang-Pei Chen

2007-07-22T23:59:59.000Z

399

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

SciTech Connect

This report summarizes the work done during the fifth quarter of the project. Effort was directed in two 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) Fabrication of porous samaria-doped ceria (SDC) and investigation of the effect of thermal treatment on its conductivity. The model developed accounts for transport through three regions: (a) Transport through the bulk of the grain, RI, which includes parallel transport through space charge region. (b) Transport through the space charge region adjacent to the neck (grain boundary), RII. (c) Transport through the structural part of the neck (grain boundary), RIII. The work on the model development involves calculation RI, RII, RIII, and the sum of these three terms, which is the total resistance, as a function of the grain radius ranging between 0.5 and 5 microns and as a function of the relative neck size, described in terms of the angle theta, ranging between 5 and 45{sup o}. Three values of resistivity of the space charge region were chosen; space charge resistivity greater than grain resistivity, equal to grain resistivity, and lower than grain resistivity. Experimental work was conducted on samaria (Sm{sub 2}O{sub 3})-doped ceria (SDC) samples of differing porosity levels, before and after thermal treatment at 1200 C. The conductivity in the annealed samples was lower, consistent with enhanced Debye length. This shows the important role of space charge on ionic transport, and its implications concerning cathode polarization.

Anil V. Virkar

2004-03-08T23:59:59.000Z

400

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

SciTech Connect

This report summarizes the work done during the second quarter of the project. Effort is directed in two areas: (1) The use of a novel method to achieve a given porosity level with high contiguity and thus conductivity. (2) Relate the measured conductivity to porosity and contiguity. The rationale for these experiments was to develop cathodes with high ionic conductivity, so that the effective polarization resistance will be concomitantly lowered.

Anil V. Virkar

2003-10-11T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

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

SciTech Connect

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.

Anil V. Virkar

2004-05-17T23:59:59.000Z

402

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

SciTech Connect

This report summarizes the work done during the first quarter of the project. Effort was directed in three areas: (1) The determination of the role of ionic conductor morphology, used in composite cathodes, on the ionic conductivity of the ionic conductor. It was shown that if the particles are not well sintered, the necks formed between particles will be very narrow, and the resulting conductivity will be too low (resistivity will be too high). Specifically, a mathematical equation was derived to demonstrate the singular nature of conductivity. (2) Nanosize powders of Sc-doped CeO{sub 2} were prepared by combustion synthesis. The rationale is that the particle size of the composite electrode must be as small as possible to ensure a high ionic conductivity--and resulting in high performance in fuel cells. Di-gluconic acid (DGA) was used as fuel. The process led to the formation of nanosize Sc-doped CeO{sub 2}. The powder was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). (3) Samples were sintered to form materials containing various levels of porosity, from {approx}3% to {approx}43%. Conductivity was measured over a range of temperatures by four probe DC method. It was observed that in highly porous samples, the conductivity was far lower than can be expected purely based on total porosity. The difference could be rationalized on the basis of the theoretical model developed.

Professor Anil V. Virkar

2003-04-14T23:59:59.000Z

403

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

SciTech Connect

This report summarizes the work done during the third quarter of the project. Effort was directed in two 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 its relationship to cathode polarization. Included indirectly through the grain boundary effect is the effect of space charge. (2) Synthesis of LSC + SDC composite cathode powders by combustion synthesis. (3) Fabrication and testing of anode-supported single cells made using synthesized LSC + ScDC composite cathodes.

Anil V. Virkar

2003-11-03T23:59:59.000Z

404

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

SciTech Connect

This report summarizes the work done during the fourth quarter of the project. Effort was directed in two areas, namely, continued 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, and its relationship to cathode polarization; and fabrication of samaria-doped ceria porous (SDC). The work on the model development involves calculation of the effect of space charge on transport through porous bodies. Three specific cases have been examined: (1) Space charge resistivity greater than the grain resistivity, (2) Space charge resistivity equal to the grain resistivity, and (3) Space charge resistivity lower than the grain resistivity. The model accounts for transport through three regions: the bulk of the grain, the space charge region, and the structural part of the grain boundary. The effect of neck size has been explicitly incorporated. In future work, the effective resistivity will be incorporated into the effective cathode polarization resistance. The results will then be compared with experiments.

Anil V. Virkar

2003-12-12T23:59:59.000Z

405

E-Print Network 3.0 - activity mammographic density Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Sciences ; Engineering 82 T. J. Brukilacchio, Ph.D. Thesis 2003 A DIFFUSE OPTICAL TOMOGRAPHY SYSTEM COMBINED Summary: , mammographic specificity is known to be limited 2....

406

Accurate and systematically improvable density functional theory embedding for correlated wavefunctions  

SciTech Connect

We analyze the sources of error in quantum embedding calculations in which an active subsystem is treated using wavefunction methods, and the remainder using density functional theory. We show that the embedding potential felt by the electrons in the active subsystem makes only a small contribution to the error of the method, whereas the error in the nonadditive exchange-correlation energy dominates. We test an MP2 correction for this term and demonstrate that the corrected embedding scheme accurately reproduces wavefunction calculations for a series of chemical reactions. Our projector-based embedding method uses localized occupied orbitals to partition the system; as with other local correlation methods, abrupt changes in the character of the localized orbitals along a reaction coordinate can lead to discontinuities in the embedded energy, but we show that these discontinuities are small and can be systematically reduced by increasing the size of the active region. Convergence of reaction energies with respect to the size of the active subsystem is shown to be rapid for all cases where the density functional treatment is able to capture the polarization of the environment, even in conjugated systems, and even when the partition cuts across a double bond.

Goodpaster, Jason D.; Barnes, Taylor A.; Miller, Thomas F., E-mail: tfm@caltech.edu [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); Manby, Frederick R., E-mail: fred.manby@bristol.ac.uk [Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 ITS (United Kingdom)

2014-05-14T23:59:59.000Z

407

Using Radio Waves to Control Fusion Plasma Density  

NLE Websites -- All DOE Office Websites (Extended Search)

simulation shows turbulent density fluctuations in the core of the Alcator C-Mod tokamak during strong electron heating. Image: Darin Ernst, MIT Recent fusion experiments on...

408

Long-wavelength density turbulence in the TFTR tokamak  

Science Journals Connector (OSTI)

Long-wavelength (k??itokamak plasma with auxiliary heating. Density fluctuations of n?/n>0.5% exist for k?tokamaks.

R. J. Fonck; G. Cosby; R. D. Durst; S. F. Paul; N. Bretz; S. Scott; E. Synakowski; G. Taylor

1993-06-14T23:59:59.000Z

409

Relationship of Quantum Entanglement to Density Functional Theory  

E-Print Network (OSTI)

The maximum von Neumann entropy principle subject to given constraints of mean values of some physical observables determines the density matrix. Similarly the stationary action principle in the case of time-dependent (dissipative) situations under similar constraints yields the density matrix. The free energy and measures of entanglement are expressed in terms of such a density matrix and thus define respective functionals of the mean values. In the light of several model calculations, it is found that the density matrix contains information about both quantum entanglement and phase transitions even though there may not be any direct relationship implied by one on the other.

A. K. Rajagopal; R. W. Rendell

2005-12-13T23:59:59.000Z

410

Time-dependent density-functional theory for open systems  

E-Print Network (OSTI)

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the Kohn-Sham reduced single-electron density matrix of the reduced system. Two approximate schemes are proposed for the self-energy density functionals, the complete second order approximation and the wide-band limit approximation. A numerical method based on the wide-band limit approximation is subsequently developed and implemented to simulate the steady and transient current through various realistic molecular devices. Simulation results are presented and discussed.

Xiao Zheng; Fan Wang; Chi Yung Yam; Yan Mo; GuanHua Chen

2007-02-27T23:59:59.000Z

411

Photon number density operator iE^?A^  

Science Journals Connector (OSTI)

A photon number density operator proportional to the dot product of the electric field and the vector potential is introduced as an alternative to the Mandel operator. In the Lorentz gauge it is the time component of the four-vector obtained by contracting the electromagnetic field tensor with the vector potential. Its other components can be interpreted as a current-density vector, and these number and current-density operators satisfy a continuity equation. The photon density operators introduced here are all products of operators that satisfy Maxwells equations and whose Lorentz and gauge transformation properties are well known.

M. Hawton and T. Melde

1995-05-01T23:59:59.000Z

412

Distribution of Radiation Density in a Homogeneous Cloudy Laye  

NLE Websites -- All DOE Office Websites (Extended Search)

A. M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow, Russia The program block (Monte-Carlo method) allowing calculating radiation density in...

413

Magnetic Susceptibility of an Electron Gas at High Density  

Science Journals Connector (OSTI)

The magnetic susceptibility of an electron gas at high density is determined using the exact theory of Gell-Mann and Brueckner.

K. A. Brueckner and K. Sawada

1958-10-15T23:59:59.000Z

414

SciTech Connect: Chiral dynamics and peripheral transverse densities  

Office of Scientific and Technical Information (OSTI)

the bsup 2-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit Msub pi -> 0 and determine their spatial support. Our...

415

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference...

416

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

Open Energy Info (EERE)

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

417

Covariance analysis for Energy Density Functionals and instabilities  

E-Print Network (OSTI)

We present the covariance analysis of two successful nuclear energy density functionals, (i) a non-relativistic Skyrme functional built from a zero-range effective interaction, and (ii) a relativistic nuclear energy density functional based on density dependent meson-nucleon couplings. Such a study is crucial for assessing the information content of an observable when predicted by a given model. The covariance analysis is a useful tool for understanding the limitations of a model, the correlations between observables and the statistical errors. We also provide a brief review, partly connected with the covariance analysis, of some instabilities displayed by several energy density functionals of current use in nuclear physics.

Roca-Maza, X; Col, G

2014-01-01T23:59:59.000Z

418

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

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

for Advanced Batteries ADVANCED MANUFACTURING OFFICE Developing a Lower Cost and Higher Energy Density Alternative to Lithium-Ion Batteries Introduction As the world moves toward...

419

The Reduced Density Matrix Method for Electronic Structure ...  

E-Print Network (OSTI)

The Reduced Density Matrix Method for Electronic Structure Calculations and the Role of Three-Index Representability Conditions. Zhengji Zhao (zz217 ***at***...

Zhengji Zhao

420

Optimization Online - Density-based Globally Convergent Trust ...  

E-Print Network (OSTI)

Jul 10, 2005 ... Density-based Globally Convergent Trust-Region Methods for Self-Consistent Field Electronic Structure Calculations. Juliano B. Francisco...

Juliano B. Francisco

2005-07-10T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Constraints on the density dependence of the symmetry energy  

E-Print Network (OSTI)

Collisions involving 112Sn and 124Sn nuclei have been simulated with the improved Quantum Molecular Dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at sub-normal density are obtained. Results from present work are compared to constraints put forward in other recent analysis.

M. B. Tsang; Yingxun Zhang; P. Danielewicz; M. Famiano; Zhuxia Li; W. G. Lynch; A. W. Steiner

2008-11-19T23:59:59.000Z

422

Constraints on the Density Dependence of the Symmetry Energy  

SciTech Connect

Collisions involving {sup 112}Sn and {sup 124}Sn nuclei have been simulated with the improved quantum molecular dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at subnormal density are obtained. The results from the present work are compared to constraints put forward in other recent analyses.

Tsang, M. B.; Danielewicz, P.; Lynch, W. G.; Steiner, A. W. [Joint Institute of Nuclear Astrophysics and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States); Zhang Yingxun [Joint Institute of Nuclear Astrophysics and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Famiano, M. [Physics Department, Western Michigan University, Kalamazoo, Michigan 49008 (United States); Li, Zhuxia [China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China)

2009-03-27T23:59:59.000Z

423

Constraints on the density dependence of the symmetry energy  

E-Print Network (OSTI)

Collisions involving 112Sn and 124Sn nuclei have been simulated with the improved Quantum Molecular Dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at sub-normal density are obtained. Results from present work are compared to constraints put forward in other recent analysis.

Tsang, M B; Danielewicz, P; Famiano, M; Li, Zhuxia; Lynch, W G; Steiner, A W

2008-01-01T23:59:59.000Z

424

Design and Control of High Power Density Motor Drive.  

E-Print Network (OSTI)

??This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing (more)

Jiang, Dong

2011-01-01T23:59:59.000Z

425

COHERENCE AND INTERMITTENCY OF ELECTRON DENSITY IN SMALL-SCALE  

NLE Websites -- All DOE Office Websites (Extended Search)

OF ELECTRON DENSITY IN SMALL-SCALE INTERSTELLAR TURBULENCE P. W. Terry and K. W. Smith Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas and...

426

Amplifying Magnetic Fields in High Energy Density Plasmas | U...  

Office of Science (SC) Website

Amplifying Magnetic Fields in High Energy Density Plasmas Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities...

427

Innovative High Energy Density Capacitor Design Offers Potential...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

like TroyCap's High Density Energy Nanolaminate Capacitor (HEDCAP) that may offer new clean energy applications to meet the nation's strategic energy goals and secure...

428

Congruent energy density trends of fish and birds reflect ecosystem ...  

Science Journals Connector (OSTI)

We used long-term biomonitoring data to calculate whole-body energy densities for Lake Huron rainbow smelt (Osmerus mordax), lake trout (Salvelinus...

429

On the properties of massive Population III stars and metal-free stellar populations  

E-Print Network (OSTI)

We present realistic models for massive Population III stars and stellar populations based on non-LTE model atmospheres, recent stellar evolution tracks and up-to-date evolutionary synthesis models, to study their spectral properties, including their dependence on age, star formation history, and IMF. (..) The main results regarding integrated stellar populations are: * For young bursts and the case of a constant SFR, nebular continuous emission - neglected in previous studies - dominates the spectrum redward of Lyman-alpha (...). Therefore predicted emission line equivalent widths are considerably smaller than found in earlier studies, whereas the detection of the continuum is eased. Nebular line and continuous emission strongly affect the broad band photometric properties of Pop III objects. * Due to stellar evolution, the hardness of the ionising spectrum decreases rapidly, leading to the disappearance of the characteristic HeII 1640 recombination lines after ~ 3 Myr in instantaneous bursts. * The relative...

Schrer, D

2001-01-01T23:59:59.000Z

430

CANDELS: THE CONTRIBUTION OF THE OBSERVED GALAXY POPULATION TO COSMIC REIONIZATION  

SciTech Connect

We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6 {approx}< z {approx}< 8. These galaxies were selected from new deep near-infrared Hubble Space Telescope imaging from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble UltraDeep Field 2009, and Wide Field Camera 3 Early Release Science programs. We investigate the contribution to reionization from galaxies that we observe directly, thus sidestepping the uncertainties inherent in complementary studies that have invoked assumptions regarding the intrinsic shape or the faint-end cutoff of the galaxy ultraviolet (UV) luminosity function. Due to our larger survey volume, wider wavelength coverage, and updated assumptions about the clumping of gas in the intergalactic medium (IGM), we find that the observable population of galaxies can sustain a fully reionized IGM at z = 6, if the average ionizing photon escape fraction (f {sub esc}) is {approx}30%. Our result contrasts with a number of previous studies that have measured UV luminosity densities at these redshifts that vary by a factor of five, with many concluding that galaxies could not complete reionization by z = 6 unless a large population of galaxies fainter than the detection limit were invoked, or extremely high values of f {sub esc} were present. The specific UV luminosity density from our observed galaxy samples at z = 7 and 8 is not sufficient to maintain a fully reionized IGM unless f {sub esc} > 50%. We examine the contribution from galaxies in different luminosity ranges and find that the sub-L* galaxies we detect are stronger contributors to the ionizing photon budget than the L > L* population, unless f {sub esc} is luminosity dependent. Combining our observations with constraints on the emission rate of ionizing photons from Ly{alpha} forest observations at z = 6, we find that we can constrain f {sub esc} < 34% (2{sigma}) if the observed galaxies are the only contributors to reionization, or <13% (2{sigma}) if the luminosity function extends to a limiting magnitude of M {sub UV} = -13. These escape fractions are sufficient to sustain an ionized IGM by z = 6. Current constraints on the high-redshift galaxy population imply that the volume ionized fraction of the IGM, while consistent with unity at z {<=} 6, appears to drop at redshifts not much higher than 7, consistent with a number of complementary reionization probes. If faint galaxies dominated the ionizing photon budget at z = 6-7, future extremely deep observations with the James Webb Space Telescope will probe deep enough to directly observe them, providing an indirect constraint on the global ionizing photon escape fraction.

Finkelstein, Steven L.; Pawlik, Andreas H. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Papovich, Casey [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Ryan, Russell E.; Ferguson, Henry C.; Koekemoer, Anton M.; Grogin, Norman A. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Finlator, Kristian [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Giavalisco, Mauro [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Dunlop, James S. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh (United Kingdom); Faber, Sandy M.; Kocevski, Dale D. [University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Newman, Jeffrey A., E-mail: stevenf@astro.as.utexas.edu [Department of Physics and Astronomy and Pitt-PACC, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

2012-10-20T23:59:59.000Z

431

How Ebola Impacts Genetics of Western Lowland Gorilla Populations  

E-Print Network (OSTI)

How Ebola Impacts Genetics of Western Lowland Gorilla Populations Pascaline J. Le Gouar1 for the genetic diversity of populations, which could enhance the species' extinction probability. The Ebola population. Although mortality rates are very high, the impacts of Ebola on genetic diversity of Western

Paris-Sud XI, Université de

432

Revisiting the Uniqueness of Simple Demographics in the US Population  

E-Print Network (OSTI)

Revisiting the Uniqueness of Simple Demographics in the US Population Philippe Golle Palo Alto% of the US population can be uniquely identified by gen- der, ZIP code and full date of birth. This short paper revisits the uniqueness of simple demographics in the US population based on the most recent

Golle, Philippe

433

Genetic Variability and Population Differentiation in Captive Baird's Tapirs  

E-Print Network (OSTI)

one of housing and displaying as diverse a collection of species as possible, to one of creating self and Ballou, 1986; Soule et al., 1986]. One obstacle to achieving a self-sustaining captive population- sustaining captive populations that may one day act as a source for restocking wild populations [Ralls

Ashley, Mary V.

434

The Impact of Residential Density on Vehicle Usage and Energy Consumption  

E-Print Network (OSTI)

Residential Density on Vehicle Usage and Energy ConsumptionResidential Density on Vehicle Usage and Energy ConsumptionResidential Density on Vehicle Usage and Energy Consumption

Golob, Thomas F; Brownstone, David

2005-01-01T23:59:59.000Z

435

The impact of residential density on vehicle usage and fuel consumption  

E-Print Network (OSTI)

residential density on vehicle usage and energy consumption.of residential density on vehicle usage and fuel consumptionresidential density on vehicle usage and fuel consumption*

Kim, Jinwon; Brownstone, David

2010-01-01T23:59:59.000Z

436

HIGH-DENSITY MOLECULAR GAS PROPERTIES OF THE STARBURST GALAXY NGC 1614 REVEALED WITH ALMA  

SciTech Connect

We present the results of HCN/HCO{sup +}/HNC J = 4-3 transition line observations of the nearby starburst galaxy NGC 1614, obtained with ALMA Cycle 0. We find that high density molecular gas traced with these lines shows a velocity structure such that the northern (southern) side of the nucleus is redshifted (blueshifted) with respect to the nuclear velocity of this galaxy. The redshifted and blueshifted emission peaks are offset by {approx}0.''6 at the northern and southern sides of the nucleus, respectively. At these offset positions, observations at infrared >3 {mu}m indicate the presence of active dusty starbursts, supporting the picture that high-density molecular gas is the site of active starbursts. The enclosed dynamical mass within the central {approx}2'' in radius, derived from the dynamics of the high-density molecular gas, is {approx}10{sup 9} M{sub Sun }, which is similar to previous estimates. Finally, the HCN emission is weaker than HCO{sup +} but stronger than HNC for J = 4-3 for all starburst regions of NGC 1614, as seen for J = 1-0 transition lines in starburst-dominated galaxies.

Imanishi, Masatoshi [Subaru Telescope, 650 North A'ohoku Place, Hilo, HI 96720 (United States); Nakanishi, Kouichiro, E-mail: masa.imanishi@nao.ac.jp [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura 763-0355, Santiago (Chile)

2013-09-15T23:59:59.000Z

437

Study of the influence of a strong magnetic field on the composition of nuclear matter at high densities and zero temperature  

SciTech Connect

Magnetars are neutron stars with a strong surface magnetic field. Observations of soft gamma-ray and anomalous X-ray pulsars pointed out that the surface magnetic field of magnetars is equal or even greater than 10{sup 15} G. In this work we study the influence of a strong magnetic field on the composition of nuclear matter at high densities and zero temperature. We describe the matter through a relativistic mean-field model with eight light baryons (baryon octet), electrons, muons and with magnetic field. As output of the numerical calculations, we obtain the relative population of each species of particles as function of baryon density.

Coelho, Eduardo L.; Chiapparini, Marcelo [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20559-900, Rio de Janeiro, RJ (Brazil); Bracco, Mirian E. [Faculdade de Tecnologia, Universidade do Estado do Rio de Janeiro, 27537-000, Resende, RJ (Brazil)

2013-03-25T23:59:59.000Z

438

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

E-Print Network (OSTI)

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.

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

439

Surface properties of liquid mercury: a comparison of density-dependent and density-independent force fields  

E-Print Network (OSTI)

The surface properties of liquid mercury (Hg) at a temperature of 293 K are investigated by classical Molecular Dynamics simulation using density-independent (DI) and density-dependent (DD) force fields. The latter force fields were introduced to improve the description of surface properties. Both force fields yield lower values of the surface tension in comparison to experimental data. Moreover, the density-dependent force field results in an anomalous thermodynamic behavior. These findings are rationalized by liquid-state theory. An optimized, density-independent force field is proposed that yields a higher surface tension and, at the same time, provides an accurate description of the liquid-vapor coexistence.

A. Iakovlev; D. Bedrov; M. Mller

2014-12-08T23:59:59.000Z

440

The Dark Bursts population in a complete sample of bright Swift Long Gamma-Ray Bursts  

E-Print Network (OSTI)

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.

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

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Breeding bird populations and habitat associations within the Savannah River Site (SRS).  

SciTech Connect

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.

Gauthreaux, Sidney, A.; Steven J. Wagner.

2005-06-29T23:59:59.000Z

442

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF LEVY PROCESSES  

E-Print Network (OSTI)

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF L´EVY PROCESSES ALEKSANDAR MIJATOVI for the existence of transition densities of X, we establish sharp convergence rates of the normalised probability class with applications in diverse areas such as mathematical finance, risk management, insurance

443

HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE  

E-Print Network (OSTI)

HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE A. Friedman1,2 , J.J.Barnard1,2 , R Energy Density regimes required for Inertial Fu- sion Energy and other applications. An interim goal we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto

Wurtele, Jonathan

444

Complex structure of electron and density functional theory  

E-Print Network (OSTI)

Effective model for electron as two particle system is considered. The first particle in the system is chargeless mass of electron. The second one is massless charge of electron. Based on this model it is shown that density of energy for the particle is proportional to the probability density and the following formula stands $\\rho_E(x)=mc^2\\rho(x)$.

K. Koshelev

2013-01-08T23:59:59.000Z

445

Density functional theory for self-bound systems  

E-Print Network (OSTI)

The density functional theory is extended to account for self-bound systems. To this end the Hohenberg-Kohn theorem is formulated for the intrinsic density and a Kohn-Sham like procedure for an $N$--body system is derived using the adiabatic approximation to account for the center of mass motion.

Nir Barnea

2007-11-06T23:59:59.000Z

446

Connections on statistical manifolds of density operators by geometry of  

E-Print Network (OSTI)

of statistical manifolds, that is of manifolds whose points can be identified with density functions with respect to a certain measure µ. The classical references for the theory can be found in the books [1, 2, 4Connections on statistical manifolds of density operators by geometry of noncommutative Lp -spaces

Isola, Tommaso

447

OPTIMIZATION OF LAYER DENSITIES FOR MULTILAYERED INSULATION SYSTEMS  

SciTech Connect

Numerous tests of various multilayer insulation systems have indicated that there are optimal densities for these systems. However, the only method of calculating this optimal density was by a complex physics based algorithm developed by McIntosh. In the 1970's much data were collected on the performance of these insulation systems with many different variables analyzed. All formulas generated included number of layers and layer density as geometric variables in solving for the heat flux, none of them was in a differentiable form for a single geometric variable. It was recently discovered that by converting the equations from heat flux to thermal conductivity using Fourier's Law, the equations became functions of layer density, temperatures, and material properties only. The thickness and number of layers of the blanket were merged into a layer density. These equations were then differentiated with respect to layer density. By setting the first derivative equal to zero, and solving for the layer density, the critical layer density was determined. This method was checked and validated using test data from the Multipurpose Hydrogen Testbed which was designed using Mcintosh's algorithm.

Johnson, W. L. [NASA Kennedy Space Center, KT-E Kennedy Space Center, FL 32899 (United States)

2010-04-09T23:59:59.000Z

448

Irradiation effects in high-density polyethylene Jussi Polvia  

E-Print Network (OSTI)

Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold energy for creating defects in the polyethylene lattice as a function of the incident angle. We found

Nordlund, Kai

449

CONCRETE OPTIMISATION WITH REGARD TO PACKING DENSITY AND RHEOLOGY  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

450

Effect of air density variations on greenhouse temperature model  

Science Journals Connector (OSTI)

Basically, a greenhouse temperature model is determined based on the balances of mass and energy. In most of the available models, the air density is considered constant. This fact limits the model because of the natural existing relationship between ... Keywords: Air density, Greenhouse, Humidity, Nonlinear systems, Temperature

Javier Leal Iga; Jorge Leal Iga; Carlos Leal Iga; Ramiro Ayala Flores

2008-05-01T23:59:59.000Z

451

Dynamical instabilities in density-dependent hadronic relativistic models  

SciTech Connect

Unstable modes in asymmetric nuclear matter (ANM) at subsaturation densities are studied in the framework of relativistic mean-field density-dependent hadron models. The size of the instabilities that drive the system are calculated and a comparison with results obtained within the nonlinear Walecka model is presented. The distillation and antidistillation effects are discussed.

Santos, A. M.; Brito, L.; Providencia, C. [Centro de Fisica Teorica, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

2008-04-15T23:59:59.000Z

452

Modeling human location data with mixtures of kernel densities  

Science Journals Connector (OSTI)

Location-based data is increasingly prevalent with the rapid increase and adoption of mobile devices. In this paper we address the problem of learning spatial density models, focusing specifically on individual-level data. Modeling and predicting a spatial ... Keywords: anomaly/novelty detection, kernel density estimation, probabilistic methods, social media, spatial, user modeling

Moshe Lichman, Padhraic Smyth

2014-08-01T23:59:59.000Z

453

Testing Uniformity versus a Monotone Density Michael Woodroofe 1  

E-Print Network (OSTI)

Testing Uniformity versus a Monotone Density Michael Woodroofe 1 The University of Michigan Jiayang Sun 2 Case Western Reserve University Abstract The paper is concerned with testing uniformity versus a monotone density. This problem arises at least in two important contexts, after transformations, testing

Sun, Jiayang

454

THE STAR FORMATION LAW AT LOW SURFACE DENSITY  

SciTech Connect

We investigate the nature of the star formation law at low gas surface densities using a sample of 19 low surface brightness (LSB) galaxies with existing H I maps in the literature, UV imaging from the Galaxy Evolution Explorer satellite, and optical images from the Sloan Digital Sky Survey. All of the LSB galaxies have (NUV - r) colors similar to those for higher surface brightness star-forming galaxies of similar luminosity indicating that their average star formation histories are not very different. Based upon four LSB galaxies with both UV and far-infrared (FIR) data, we find FIR/UV ratios significantly less than 1, implying low amounts of internal UV extinction in LSB galaxies. We use the UV images and H I maps to measure the star formation rate (SFR) and hydrogen gas surface density within the same region for all the galaxies. The LSB galaxy star formation rate surface densities lie below the extrapolation of the power law fit to the SFR surface density as a function of the total gas density for higher surface brightness galaxies. Although there is more scatter, the LSB galaxies also lie below a second version of the star formation law in which the SFR surface density is correlated with the gas density divided by the orbital time in the disk. The downturn seen in both star formation laws is consistent with theoretical models that predict lower star formation efficiencies in LSB galaxies due to the declining molecular fraction with decreasing density.

Wyder, Ted K.; Martin, D. Christopher; Barlow, Tom A.; Foster, Karl; Friedman, Peter G.; Morrissey, Patrick; Neill, James D. [California Institute of Technology, MC 278-17, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Neff, Susan G. [Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD, 20771 (United States); Schiminovich, David [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Seibert, Mark; Madore, Barry F. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Bianchi, Luciana [Center for Astrophysical Sciences, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Donas, Jose; Milliard, Bruno [Laboratoire d'Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12 (France); Heckman, Timothy M.; Szalay, Alex S. [Department of Physics and Astronomy, Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Lee, Young-Wook; Yi, Sukyoung K. [Center for Space Astrophysics, Yonsei University, Seoul 120-749 (Korea, Republic of); Rich, R. Michael [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

2009-05-10T23:59:59.000Z

455

Locating a Recycling Center: The General Density Case Jannett Highfill  

E-Print Network (OSTI)

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

Mou, Libin

456

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems  

E-Print Network (OSTI)

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems K. Minoglou.minoglou@imel.demorkitos.gr Abstract. The study of high density integrated optoelectronic circuits involves the development of hybrid integration technologies and the generation of models for the optoelectronic devices. To meet these goals

Kouroupetroglou, Georgios

457

Relativistic plasma nanophotonics for ultrahigh energy density physics  

E-Print Network (OSTI)

Relativistic plasma nanophotonics for ultrahigh energy density physics Michael A. Purvis1 volumetrically heat dense matter into a new ultrahot plasma regime. Electron densities nearly 100 times greater) and gigabar press- ures only exceeded in the central hot spot of highly compressed thermonuclear fusion

Rocca, Jorge J.

458

Envelope of Fracture Density Dragana Todorovic-Marinic*  

E-Print Network (OSTI)

Envelope of Fracture Density Dragana Todorovic-Marinic* Veritas DGC Ltd., Calgary, Alberta, Canada that interpretation of fractures can be improved by using the envelope of the fracture density. It has been shown that open, fluid (or gas) filled fractures can be identified through the use of the AVAZ method (Gray et. al

Santos, Juan

459

Level densities for nuclei with 20<~A<~41  

Science Journals Connector (OSTI)

Some commonly used level density compilations are compared with one another and with data in the mass range 20~20?MeV) data. This new compilation is used as a benchmark for testing theoretical calculations of level densities utilizing the two-body interaction with moment methods.

Po-lin Huang; S. M. Grimes; T. N. Massey

2000-07-19T23:59:59.000Z

460

YONSEI EVOLUTIONARY POPULATION SYNTHESIS (YEPS) MODEL. I. SPECTROSCOPIC EVOLUTION OF SIMPLE STELLAR POPULATIONS  

SciTech Connect

We present a series of papers on the 2012 version of the Yonsei Evolutionary Population Synthesis (YEPS) model, which was constructed based on over 20 years of research. This first paper delineates the spectroscopic aspect of integrated light from stellar populations older than 1 Gyr. The standard YEPS is based on the most up-to-date Yonsei-Yale stellar evolutionary tracks and BaSel 3.1 flux libraries, and provides absorption line indices of the Lick/IDS system and high-order Balmer lines for simple stellar populations as functions of stellar parameters, such as metallicity, age, and {alpha}-element mixture. Special care has been taken to incorporate a systematic contribution from horizontal-branch (HB) stars, which alters the temperature-sensitive Balmer lines significantly, resulting in up to a 5 Gyr difference in the age estimation of old, metal-poor stellar populations. We also find that HBs exert an appreciable effect not only on the Balmer lines but also on the metallicity-sensitive lines, including the magnesium index. This is critical in explaining the intriguing bimodality found in index distributions of globular clusters in massive galaxies and to accurately derive spectroscopic metallicities from various indices. A full set of the spectroscopic and photometric YEPS model data of the entire parameter space is currently downloadable at http://web.yonsei.ac.kr/cosmic/data/YEPS.htm.

Chung, Chul; Yoon, Suk-Jin; Lee, Sang-Yoon; Lee, Young-Wook, E-mail: ywlee2@yonsei.ac.kr [Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of)

2013-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

DNA Activity  

NLE Websites -- All DOE Office Websites (Extended Search)

DNA Activity DNA Activity Name: Sara Location: N/A Country: N/A Date: N/A Question: Is DNA an anion or a cation? I thought since it was negatively charged it was an anion but mt teacher in class today said it was a cation because negatively charged molecules logically migrate to the positively charged plate of the cathode, ie molecules that migrate towards a cathode are cations. Where is the error in my logic or there error in my logic? Replies: DNA is negatively charged due to the phosphate ions present in the ribose-phosphate backbone. It moves towards the positive pole during electrophoresis. The definition kation/anion is confusing because: 1. a cation moves to the cathode 2. the cathode is negative, thus 3. a cation is positive DNA is an anion. The confusion is that a cathode is negative, but a cation is positively charged. For that reason these terms are not generally used in this context.

462

Innovative High Energy Density Capacitor Design Offers Potential for Clean  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Innovative High Energy Density Capacitor Design Offers Potential Innovative High Energy Density Capacitor Design Offers Potential for Clean Energy Applications Innovative High Energy Density Capacitor Design Offers Potential for Clean Energy Applications June 10, 2011 - 4:46pm Addthis Similar system to the clustering tool that will manufacture TroyCap’s High Energy Density Nanolaminate Capacitor | Credit: TroyC Similar system to the clustering tool that will manufacture TroyCap's High Energy Density Nanolaminate Capacitor | Credit: TroyC Ben Squires Analyst, Office of Energy Efficiency & Renewable Energy Can you imagine a photovoltaic module that's able to generate and store electricity on its own? Or an electric vehicle (EV) powered by a technology more durable than the advanced batteries in today's EVs? Malvern,

463

Innovative High Energy Density Capacitor Design Offers Potential for Clean  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Energy Density Capacitor Design Offers Potential High Energy Density Capacitor Design Offers Potential for Clean Energy Applications Innovative High Energy Density Capacitor Design Offers Potential for Clean Energy Applications June 10, 2011 - 4:46pm Addthis Similar system to the clustering tool that will manufacture TroyCap’s High Energy Density Nanolaminate Capacitor | Credit: TroyC Similar system to the clustering tool that will manufacture TroyCap's High Energy Density Nanolaminate Capacitor | Credit: TroyC Ben Squires Analyst, Office of Energy Efficiency & Renewable Energy Can you imagine a photovoltaic module that's able to generate and store electricity on its own? Or an electric vehicle (EV) powered by a technology more durable than the advanced batteries in today's EVs? Malvern, Pennsylvania's TroyCap, LLC is using nanolaminate technology patented by

464

Symmetry Energy as a Function of Density and Mass  

E-Print Network (OSTI)

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L~95 MeV and K_{sym}~25 MeV.

Pawel Danielewicz; Jenny Lee

2007-08-21T23:59:59.000Z

465

Symmetry Energy as a Function of Density and Mass  

SciTech Connect

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a{sub a}{sup V} = (31.5-33.5) MeV for the volume coefficient and a{sub a}{sup S} = (9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L{approx}95 MeV and K{sub sym}{approx}25 MeV.

Danielewicz, Pawel; Lee, Jenny [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

2007-10-26T23:59:59.000Z

466

Symmetry Energy as a Function of Density and Mass  

E-Print Network (OSTI)

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L~95 MeV and K_{sym}~25 MeV.

Danielewicz, Pawel

2007-01-01T23:59:59.000Z

467

Energy per Particle of Neutron Matter near Nuclear Density  

Science Journals Connector (OSTI)

The energy per particle of neutron matter in the density range 1013to1015gcm3 was calculated self-consistently using recent nuclear potentials: the Bressel-Kerman-Rouben potential and the boundary-condition model of Feshbach and Lomon. At low densities the results are in good agreement with other calculations of the energy density of neutron matter. At higher densities, the predicted energy density depends more strongly on the specific potential used. More recent potentials yield somewhat lower pressures for neutron matter (hence a smaller mass range for neutron stars) than those predicted with the Levinger-Simmons potential which has been used as the basis for calculations of neutron-star structure.

Sara L. Schlenker and E. L. Lomon

1971-04-01T23:59:59.000Z

468

Journal of Theoretical Biology 227 (2004) 397401 Evolutionary stability for large populations  

E-Print Network (OSTI)

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

Gordon, Geoffrey J.

469

On the properties of massive Population III stars and metal-free stellar populations  

E-Print Network (OSTI)

We present realistic models for massive Population III stars and stellar populations based on non-LTE model atmospheres, recent stellar evolution tracks and up-to-date evolutionary synthesis models, to study their spectral properties, including their dependence on age, star formation history, and IMF. (..) The main results regarding integrated stellar populations are: * For young bursts and the case of a constant SFR, nebular continuous emission - neglected in previous studies - dominates the spectrum redward of Lyman-alpha (...). Therefore predicted emission line equivalent widths are considerably smaller than found in earlier studies, whereas the detection of the continuum is eased. Nebular line and continuous emission strongly affect the broad band photometric properties of Pop III objects. * Due to stellar evolution, the hardness of the ionising spectrum decreases rapidly, leading to the disappearance of the characteristic HeII 1640 recombination lines after ~ 3 Myr in instantaneous bursts. * The relative efficiency of ionising photon energy to heavy element rest mass production, eta, of metal-poor and metal-free populations is increased by factors of ~ 4 to 18 with respect to solar metallicity and for ``standard'' IMFs. * The lowest values of eta ~ 1.6 - 2.2 % are obtained for IMFs exclusively populated with high mass stars (M_low >~ 50 Msun). If correct, the yields dominated by pair creation SNae then predict large overabundances of O/C and Si/C compared to solar abundance ratios. Detailed results are given in tabular form and as fit formulae for implementation in other calculations. (abridged abstract)

Daniel Schaerer

2001-10-31T23:59:59.000Z

470

A NEW POPULATION OF HIGH-z, DUSTY Ly{alpha} EMITTERS AND BLOBS DISCOVERED BY WISE: FEEDBACK CAUGHT IN THE ACT?  

SciTech Connect

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.

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

471

Device for the reduction of population dose  

SciTech Connect

Conventional dental radiographic procedures do not permit direct visualization of the radiation field or the central ray. As a result, it is necessary to use a beam diameter larger than the film in order to prevent an unnecessarily high number of cone cuts or other errors during visual alignment of the cone and film. The modification of a conventional dental x-ray cone which permits the central ray to be depicted by a beam of light is described. The use of the device significantly reduced the number of cone cuts, even when small beam diameters were used. Visualization of the central ray improved radiographic accuracy and has the potential to significantly reduce the over-all dose to the population by reducing the size of the field used for dental radiography.

Kihara, T.; Uchinoumi, K.; Akagi, F.; Antoku, S.

1982-06-01T23:59:59.000Z

472

Neutron activation analysis  

Science Journals Connector (OSTI)

Neutron activation analysis ... Describes the science and techniques of neutron activation analysis. ...

H. R. Lukens

1967-01-01T23:59:59.000Z

473

Measuring and Modeling Fault Density for Plume-Fault Encounter Probability Estimation  

SciTech Connect

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.

Jordan, P.D.; Oldenburg, C.M.; Nicot, J.-P.

2011-05-15T23:59:59.000Z

474

QUENCHING STAR FORMATION AT INTERMEDIATE REDSHIFTS: DOWNSIZING OF THE MASS FLUX DENSITY IN THE GREEN VALLEY  

SciTech Connect

The bimodality in galaxy properties has been observed at low and high redshifts, with a clear distinction between star-forming galaxies in the blue cloud and passively evolving objects in the red sequence; the absence of galaxies with intermediate properties indicates that the quenching of star formation and subsequent transition between populations must happen rapidly. In this paper, we present a study of over 100 transiting galaxies in the so-called green valley at intermediate redshifts (z {approx} 0.8). By using very deep spectroscopy with the DEIMOS instrument at the Keck telescope we are able to infer the star formation histories of these objects and measure the stellar mass flux density transiting from the blue cloud to the red sequence when the universe was half its current age. Our results indicate that the process happened more rapidly and for more massive galaxies in the past, suggesting a top-down scenario in which the massive end of the red sequence is forming first. This represents another aspect of downsizing, with the mass flux density moving toward smaller galaxies in recent times.

Goncalves, Thiago S.; Menendez-Delmestre, Karin [Observatorio do Valongo, Universidade Federal do Rio de Janeiro, Ladeira Pedro Antonio, 43, Saude 20080-090 Rio de Janeiro (Brazil); Martin, D. Christopher; Wyder, Ted K. [California Institute of Technology, MC 278-17, Pasadena, CA 91125 (United States); Koekemoer, Anton, E-mail: tsg@astro.ufrj.br [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2012-11-01T23:59:59.000Z

475

Stellar acoustic radii, mean densities and ages from seismic inversion techniques  

E-Print Network (OSTI)

Context. Determining stellar characteristics such as the radius, the mass or the age is crucial when studying stellar evolution, exoplanetary systems or characterising stellar populations in the Galaxy. Asteroseismology is the golden path to accurately obtain these characteristics. In this context, a key question is how to make these methods less model-dependant. Aims. Building on the work of Reese et al. (2012), we wish to extend the SOLA inversion technique to new stellar global characteristics in addition to the mean density. The goal is to provide a general framework in which to estimate these characteristics as accurately as possible in low mass main sequence stars. Methods. First, we describe our framework and discuss the reliability of the inversion technique and the possible sources of error.We then apply this methodology to the acoustic radius, an age indicator based on the sound speed derivative and the mean density and compare it to estimates based on the average large and small frequency separatio...

Buldgen, Gal; Dupret, Marc-Antoine; Samadi, Rza

2014-01-01T23:59:59.000Z

476

On Stellar Coronae and Solar Active Regions  

Science Journals Connector (OSTI)

Based on Yohkoh Soft X-Ray Telescope (SXT) observations of the Sun near peak activity level obtained on 1992 January 6, we search for coronal structures that have emission measure distributions EM(T) that match the observed stellar coronal emission measure distributions derived for the intermediate-activity stars Eri (K2 V) and ?BooA (G8 V) from Extreme Ultraviolet Explorer spectroscopic observations. We find that the temperatures of the peaks of the observed stellar distributions EM(T), as well as their slopes in the temperature range 6.0 log T 6.5, are very similar to those obtained for the brightest of the solar active regions in the 1992 January 6 SXT images. The observed slopes correspond approximately to EM ? T? with ? ~ 4, which is much steeper than predicted by static, uniformly heated loop models. Plasma densities in the coronae of Eri and ?BooA are also observed to be essentially the same as the plasma densities typical of solar active regions. These data provide the best observational support yet obtained for the hypothesis that solar-like stars up to the activity levels of Eri (K2 V) and ?BooA are dominated by active regions similar to, though possibly considerably larger than, those observed on the Sun. The surface filling factor of bright active regions needed to explain the observed stellar emission measures is approximately unity. We speculate on the scenario in which small-scale "nanoflares" dominate the heating of active regions up to activity levels similar to those of Eri (K2 V) and ?BooA. At higher activity levels still, the interactions of the active regions themselves may lead to increasing flaring on larger scales that is responsible for heating plasma to the observed coronal temperatures of T 107K on very active stars. Observations of X-ray and EUV light curves using more sensitive instruments than are currently available, together with determinations of plasma densities over the full range of coronal temperatures (106-107K and higher), will be important to confirm flare heating hypotheses and to elicit further details concerning coronal structures at solar-like active region temperatures (T 5 ? 106K) and the temperatures that characterize the most active stars (T 107K).

Jeremy J. Drake; Giovanni Peres; Salvatore Orlando; J. Martin Laming; Antonio Maggio

2000-01-01T23:59:59.000Z

477

Modeling population connectivity by ocean currents, a graph-theoretic approach for marine conservation  

Science Journals Connector (OSTI)

The dispersal of individuals among marine populations is of great importance to metapopulation dynamics, population persistence, and species expansion. Understanding this connectivity between distant populations ...

Eric A. Treml; Patrick N. Halpin; Dean L. Urban; Lincoln F. Pratson

2008-01-01T23:59:59.000Z

478

STP Resources for Statistical & Thermal Physics Density of States of the Two-Dimensional Ising Model  

E-Print Network (OSTI)

STP Resources for Statistical & Thermal Physics Density of States of the Two-Dimensional Ising Model: STP IsingDensityOfStates FIG. 1: Plot of the density of states generated by stp IsingDensityOfStates. I. INTRODUCTION The STP IsingDensityOfStates program computes the density of states of the two

Holzwarth, Natalie

479

Bar-Halo Friction in Galaxies III: Halo Density Changes  

E-Print Network (OSTI)

The predicted central densities of dark matter halos in LCDM models exceed those observed in some galaxies. Weinberg & Katz argue that angular momentum transfer from a rotating bar in the baryonic disk can lower the halo density, but they also contend that N-body simulations of this process will not reveal the true continuum result unless many more than the usual numbers of particles are employed. Adopting their simplified model of a rotating rigid bar in a live halo, I have been unable to find any evidence to support their contention. I find that both the angular momentum transferred and the halo density change are independent of the number of particles over the range usually employed up to that advocated by these authors. I show that my results do not depend on any numerical parameters, and that field methods perform equally with grid methods. I also identify the reasons that the required particle number suggested by Weinberg & Katz is excessive. I further show that when countervailing compression by baryonic settling is ignored, moderate bars can reduce the mean density of the inner halo by 20% - 30%. Long, massive, skinny bars can reduce the mean inner density by a factor ~10. The largest density reductions are achieved at the expense of removing most of the angular momentum likely to reside in the baryonic component. Compression of the halo by baryonic settling must reduce, and may even overwhelm, the density reduction achievable by bar friction.

J. A. Sellwood

2006-10-16T23:59:59.000Z

480

Dworshak Kokanee Population and Entrainment Assessment 2005-2006 Annual Report.  

SciTech Connect

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.

Stark, Eric J. [Idaho Department of Fish and Game

2008-11-06T23:59:59.000Z

Note: This page contains sample records for the topic "activity population density" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Using Dung to Estimate Gorilla Density: Modeling Dung Production Rate  

E-Print Network (OSTI)

, and diseases such as Ebola hemorrhagic fever. Ape populations have declined drastically in the last 2 decades (Walsh et al. 2003); a recent outbreak of Ebola in Congo caused a massive die-off (ca. 5000 gorillas

482

High-Density Discharges in the Alcator Tokamak  

Science Journals Connector (OSTI)

Peak plasma densities in excess of 1015 cm-3 have been obtained in the Alcator tokamak with 60<~BT<85 kG. The highest average density so far achieved is ne=61014 cm-3; the corresponding n0?E=21013 cm-3 s. These ultrahigh-density discharges exhibit (i) nearly complete energy equilibration between electrons and ions, (ii) severe attenuation of energetic-neutral-particle fluxes, (iii) a minor role of impurities, and (iv) energy-confinement properties consistent with neoclassical estimates.

M. Gaudreau; A. Gondhalekar; M. H. Hughes; D. Overskei; D. S. Pappas; R. R. Parker; S. M. Wolfe; E. Apgar; H. I. Helava; I. H. Hutchinson; E. S. Marmar; K. Molvig

1977-11-14T23:59:59.000Z

483

Density dependence of reactor performance with thermal confinement scalings  

SciTech Connect

Energy confinement scalings for the thermal component of the plasma published thus far have a different dependence on plasma density and input power than do scalings for the total plasma energy. With such thermal scalings, reactor performance (measured by Q, the ratio of the fusion power to the sum of the ohmic and auxiliary input powers) worsens with increasing density. This dependence is the opposite of that found using scalings based on the total plasma energy, indicating that reactor operation concepts may need to be altered if this density dependence is confirmed in future research.

Stotler, D.P.

1992-03-01T23:59:59.000Z

484

Exact evaluation of density matrix elements for the Heisenberg chain  

E-Print Network (OSTI)

We have obtained all the density matrix elements on six lattice sites for the spin-1/2 Heisenberg chain via the algebraic method based on the quantum Knizhnik-Zamolodchikov equations. Several interesting correlation functions, such as chiral correlation functions, dimer-dimer correlation functions, etc... have been analytically evaluated. Furthermore we have calculated all the eigenvalues of the density matrix and analyze the eigenvalue-distribution. As a result the exact von Neumann entropy for the reduced density matrix on six lattice sites has been obtained.

Jun Sato; Masahiro Shiroishi; Minoru Takahashi

2006-11-06T23:59:59.000Z

485

Energy Density Inhomogeneities with Polynomial $f(R)$ Cosmology  

E-Print Network (OSTI)

In this paper, we study the effects of polynomial $f(R)$ model on the stability of homogeneous energy density in self-gravitating spherical stellar object. For this purpose, we construct couple of evolution equations which relate the Weyl tensor with matter parameters. We explore different factors responsible for density inhomogeneities with non-dissipative dust, isotropic as well as anisotropic fluids and dissipative dust cloud. We find that shear, pressure, dissipative parameters and $f(R)$ terms affect the existence of inhomogeneous energy density.

Sharif, M

2015-01-01T23:59:59.000Z

486

Sensitivity of nuclear stopping towards density dependent symmetry energy  

E-Print Network (OSTI)

The effect of density dependent symmetry energy on nuclear-stopping is studied using isospin-dependent quantum molecular dynamics model(IQMD). We have used the reduced isospin-dependent cross-section with soft(S) equation of state for the systems having different isostopic content, to explore the various aspects of nuclear stopping. The aim is to pin down the nature of the nuclear stopping with density dependent symmetry energy. Nuclear stopping is found to be sensitive towards the various forms of the density dependent symmetry energy. The nuclear stopping tends to decrease for the stiffer equation of state (EOS), i.e. larger values of gamma.

Karan Singh Vinayak; Suneel Kumar

2011-10-11T23:59:59.000Z

487

Nuclear Energy Density Functionals Constrained by Low-Energy QCD  

E-Print Network (OSTI)

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.

Dario Vretenar

2008-02-06T23:59:59.000Z

488

Symmetry energy at subnuclear densities deduced from nuclear masses  

E-Print Network (OSTI)

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.

Kazuhiro Oyamatsu; Kei Iida

2010-04-19T23:59:59.000Z

489

The Density Effect for the Ionization Loss in Various Materials  

Science Journals Connector (OSTI)

The density effect for the ionization loss of charged particles has been calculated for a number of metals, scintillating materials, gases at various pressures, and photographic emulsion, using a dispersion model involving an appropriate number of dispersion oscillators for each substance. The results are presented in the form of graphs which can be used to correct the ionization loss for the density effect. The theoretical curves for silver chloride and anthracene are in reasonable agreement with experiments on the ionization loss of ?-mesons. A general derivation of the equations for the density effect is given.

R. M. Sternheimer

1952-11-15T23:59:59.000Z

490

The Stellar Population Histories of Local Early-Type Galaxies. I. Population Parameters  

E-Print Network (OSTI)

We present single stellar population (SSP) equivalent ages, metallicities, and abundance ratios for local elliptical galaxies derived from Hbeta, Mgb, and absorption line strengths. We use an extension of the Worthey (1994) stellar population models that incorporates non-solar line-strength "response functions" by Tripicco & Bell (1995), allowing us to correct the models for the enhancements of Mg and other alpha-like elements relative to the Fe-peak elements. SSP-equivalent ages of local ellipticals from Gonzalez (1993) are found to vary widely, 1.5 =+0.26 and =+0.20 (in an aperture of radius Re/8). The enhancement ratios are milder than previous estimates, owing to the application of non-solar abundance corrections to both Mgb and for the first time. Gradients in stellar populations within galaxies are found to be mild, with SSP-equivalent age decreasing by 25%, metallicity decreasing by =0.20 dex, and [E/Fe] remaining nearly constant out to an aperture of radius Re/2 for nearly all systems. Our ages have an overall zeropoint uncertainty of at least 25% due to uncertainties in the stellar evolution prescription, the oxygen abundance, the effect of non-solar abundances on the isochrones, and other unknowns. However, the relative age rankings of stellar populations should be largely unaffected by these errors. In particular, the large spread in ages appears to be real and cannot be explained by contamination of Hbeta by blue stragglers or hot horizontal branch stars, or by fill-in of Hbeta by emission. Correlations between these derived SSP-equivalent parameters and other galaxy observables will be discussed in future papers. (Abridged)

S. C. Trager; S. M. Faber; Guy Worthey; J. Jesus Gonzalez

2000-01-06T23:59:59.000Z

491

Electron density measurements of atmospheric-pressure non-thermal N2 plasma jet by Stark broadening and irradiance intensity methods  

Science Journals Connector (OSTI)

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 1020/m3 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.

2014-01-01T23:59:59.000Z

492

Simulated population responses of common carp to commercial exploitation  

SciTech Connect

Common carp Cyprinus carpio is a widespread invasive species that can become highly abundant and impose deleterious ecosystem effects. Thus, aquatic resource managers are interested in controlling common carp populations. Control of invasive common carp populations is difficult, due in part to the inherent uncertainty of how populations respond to exploitation. To understand how common carp populations respond to exploitation, we evaluated common carp population dynamics (recruitment, growth, and mortality) in three natural lakes in eastern South Dakota. Common carp exhibited similar population dynamics across these three systems that were characterized by consistent recruitment (ages 3 to 15 years present), fast growth (K = 0.37 to 0.59), and low mortality (A = 1 to 7%). We then modeled the effects of commercial exploitation on size structure, abundance, and egg production to determine its utility as a management tool to control populations. All three populations responded similarly to exploitation simulations with a 575-mm length restriction, representing commercial gear selectivity. Simulated common carp size structure modestly declined (9 to 37%) in all simulations. Abundance of common carp declined dramatically (28 to 56%) at low levels of exploitation (0 to 20%) but exploitation >40% had little additive effect and populations were only reduced by 49 to 79% despite high exploitation (>90%). Maximum lifetime egg production was reduced from 77 to 89% at a moderate level of exploitation (40%), indicating the potential for recruitment overfishing. Exploitation further reduced common carp size structure, abundance, and egg production when simulations were not size selective. Our results provide insights to how common carp populations may respond to exploitation. Although commercial exploitation may be able to partially control populations, an integrated removal approach that removes all sizes of common carp has a greater chance of controlling population abundance and reducing perturbations induced by this invasive species.

Weber, Michael J.; Hennen, Matthew J.; Brown, Michael L.

2011-12-01T23:59:59.000Z

493

Soil Density/Moisture Gauge | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Soil Density/Moisture Gauge Soil Density/Moisture Gauge Soil Density/Moisture Gauge This scenario provides the planning instructions, guidance, and evaluation forms necessary to conduct an exercise involving a highway shipment of a soil moisture/density gauge (Class 7 - Radioactive). This exercise manual is one in a series of five scenarios developed by the Department of Energy Transportation Emergency Preparedness Program (TEPP). Responding agencies may include several or more of the following: local municipal and county fire, police, sheriff and Emergency Medical Services (EMS) personnel; state, local, and federal emergency response teams; emergency response contractors; and other emergency response resources that could potentially be provided by the carrier and the originating facility (shipper).

494

Measuring Densities of Solids and Liquids Using Magnetic Levitation: Fundamentals  

Science Journals Connector (OSTI)

Measuring Densities of Solids and Liquids Using Magnetic Levitation: Fundamentals ... This article also describes the fundamental limitations of this technique. ... The Measurement, Instrumentation, and Sensors Handbook; CRC Press and IEEE Press: Boca Raton, FL, 1999. ...

Katherine A. Mirica; Sergey S. Shevkoplyas; Scott T. Phillips; Malancha Gupta; George M. Whitesides

2009-07-02T23:59:59.000Z

495

Display of probability densities for data from a continuous distribution  

E-Print Network (OSTI)

Based on cumulative distribution functions, Fourier series expansion and Kolmogorov tests, we present a simple method to display probability densities for data drawn from a continuous distribution. It is often more efficient than using histograms.

Bernd A. Berg

2011-05-03T23:59:59.000Z

496

Direct Experimental Determination of Spectral Densities of Molecular Complexes  

E-Print Network (OSTI)

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.

Pachon, Leonardo A

2014-01-01T23:59:59.000Z

497

Why are Fluid Densities So Low in Carbon Nanotubes?  

E-Print Network (OSTI)

The equilibrium density of fluids under nanoconfinement can differ substantially from their bulk density. Using a mean-field approach to describe the energetic landscape near the carbon nanotube (CNT) wall, we obtain analytical results describing the lengthscales associated with the layering observed at the fluid-CNT interface. When combined with molecular simulation results for the fluid density in the layered region, this approach allows us to derive a closed-form prediction for the overall equilibrium fluid density as a function of the CNT radius that is in excellent agreement with molecular dynamics simulations. We also show how aspects of this theory can be extended to describe water confined within CNTs and find good agreement with results from the literature.

Wang, Gerald J

2014-01-01T23:59:59.000Z

498

Optimal-transport formulation of electronic density-functional theory  

E-Print Network (OSTI)

The most challenging scenario for Kohn-Sham density functional theory, that is when the electrons move relatively slowly trying to avoid each other as much as possible because of their repulsion (strong-interaction limit), is reformulated here as an optimal transport (or mass transportation theory) problem, a well established field of mathematics and economics. In practice, we show that solving the problem of finding the minimum possible internal repulsion energy for $N$ electrons in a given density $\\rho(\\rv)$ is equivalent to find the optimal way of transporting $N-1$ times the density $\\rho$ into itself, with cost function given by the Coulomb repulsion. We use this link to put the strong-interaction limit of density functional theory on firm grounds and to discuss the potential practical aspects of this reformulation.

Giuseppe Buttazzo; Luigi De Pascale; Paola Gori-Giorgi

2012-05-21T23:59:59.000Z

499

Magnetic moments of octet baryons at finite density and temperature  

E-Print Network (OSTI)

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.

C. Y. Ryu; C. H. Hyun; M. -K. Cheoun

2010-08-12T23:59:59.000Z

500

Contour extraction by mixture density description obtained from region clustering  

Science Journals Connector (OSTI)

This paper describes a contour extraction scheme which refines a roughly estimated initial contour to outline a precise object boundary. In our approach, mixture density descriptions, which are parametric desc...

Minoru Etoh; Yoshiaki Shirai; Minoru Asada

1992-01-01T23:59:59.000Z