Sample records for halogen bulbs halo

  1. GREEN LIVING Replace incandencent and halogen light bulbs with LED and CLFs

    E-Print Network [OSTI]

    Thaxton, Christopher S.

    GREEN LIVING GUIDE ENERGY TRAVEL FOOD sustain yosef WATER Replace incandencent and halogen light for your laundry RESIST THAT SWITCH! Use natural light during the day, and no lights when you are gone USE MORE THAN YOU CAN EAT, reduce your waste stream DRINK FAIR TRADE COFFEE - Check out Conrad

  2. Jacketed lamp bulb envelope

    DOE Patents [OSTI]

    MacLennan, Donald A. (Gaithersburg, MD); Turner, Brian P. (Damascus, MD); Gitsevich, Aleksandr (Gaithersburg, MD); Bass, Gary K. (Mt. Airy, MD); Dolan, James T. (Frederick, MD); Kipling, Kent (Gaithersburg, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Leng, Yongzhang (Damascus, MD); Levin, Izrail (Silver Spring, MD); Roy, Robert J. (Frederick, MD); Shanks, Bruce (Gaithersburg, MD); Smith, Malcolm (Alexandria, VA); Trimble, William C. (Columbia, MD); Tsai, Peter (Olney, MD)

    2001-01-01T23:59:59.000Z

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  3. Wiring Switches to Light Bulbs

    E-Print Network [OSTI]

    Buckley, Stephen M

    2011-01-01T23:59:59.000Z

    Given n buttons and n bulbs so that the ith button toggles the ith bulb and at most two other bulbs, we compute the sharp lower bound on the number of bulbs that can be lit regardless of the action of the buttons.

  4. Solar light bulb

    SciTech Connect (OSTI)

    Smith, D.A.

    1983-07-26T23:59:59.000Z

    A system for generating light directly using solar energy is provided herein. It includes a concentrator and accumulator for the sun's rays to generate a concentrated beam of visible solar radiation. A distributor shaft is provided for distributing the beam of visible solar radiation. A fork is provided in the distributor shaft to define a plurality of branch lines, each provided with a mirror at the intersection to direct the beam down the respective branch line to permit parallel fractions of the beam to be reflected off the respective mirrors and to pass down the respective branch line. A solar bulb is provided including a double walled upper bulbous portion including the inlet from the branch line and a pair of heat outlet tubes, and a double walled lower bulbous portion, the upper portion thereof being divergently reflective, with the lower portion having walls which are either transparent or translucent to provide greater light diffusion, and the space between the two walls being maintained under vacuum to provide heat insulation values. A structure is provided within the solar bulb for the absorption and radiation of the concentrated beam of visible solar radiation. Preferably structure is provided connected to the solar bulb to draw in outside air in the summer to direct it past the solar bulb and to air vent hot air produced at the solar bulb to the outside, thereby providing light with minimal heat in the summer. The same structure is operated in the winter to draw in household air to direct it past the solar bulb and to recirculate such heated air produced at the solar bulb to the house, thereby providing light and heat in the winter.

  5. Bulb mounting of solar cell

    SciTech Connect (OSTI)

    Thompson, M.E.

    1983-04-05T23:59:59.000Z

    An energy converting assembly is provided for parasiting of light from a fluorescent light bulb utilizing a solar cell. The solar cell is mounted on a base member elongated in the dimension of elongation of the fluorescent bulb, and electrical interconnections to the cell are provided. A flexible sheet of opaque material having a flat white interior reflective surface surrounds the fluorescent bulb and reflects light emitted from the bulb back toward the bulb and the solar cell. The reflective sheet is tightly held in contact with the bottom of the bulb by adhesive, a tie strap, an external clip, or the like.

  6. Waste Toolkit A-Z Light bulbs

    E-Print Network [OSTI]

    Melham, Tom

    Waste Toolkit A-Z Light bulbs Can I recycle light bulbs? It depends what type of bulbs you have of in the normal University waste bins (landfill waste). Energy saving bulbs and fluorescent tubes are classified light bulbs? Standard filament bulbs Put in the waste bin (landfill waste) as these are not classified

  7. Halogenated solvent remediation

    DOE Patents [OSTI]

    Sorenson, Kent S.

    2004-08-31T23:59:59.000Z

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  8. Halogenated solvent remediation

    DOE Patents [OSTI]

    Sorenson, Jr., Kent S. (Windsor, CO)

    2008-11-11T23:59:59.000Z

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid--such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

  9. Lamp bulb with integral reflector

    DOE Patents [OSTI]

    Levin, Izrail (Silver Spring, MD); Shanks, Bruce (Gaithersburg, MD); Sumner, Thomas L. (Wheaton, MD)

    2001-01-01T23:59:59.000Z

    An improved electrodeless discharge lamp bulb includes an integral ceramic reflector as a portion of the bulb envelope. The bulb envelope further includes two pieces, a reflector portion or segment is cast quartz ceramic and a light transmissive portion is a clear fused silica. In one embodiment, the cast quartz ceramic segment includes heat sink fins or stubs providing an increased outside surface area to dissipate internal heat. In another embodiment, the quartz ceramic segment includes an outside surface fused to eliminate gas permeation by polishing.

  10. Dendritic processing within olfactory bulb circuits

    E-Print Network [OSTI]

    Betz, William J.

    Dendritic processing within olfactory bulb circuits Nathan E. Schoppa1 and Nathan N. Urban2 1 of the olfactory bulb. How- ever, the mechanisms by which this map is transformed into an odor code by the bulb circuitry remain unclear. Recent physiological studies in bulb slices have ident- ified several synaptic

  11. Halogenation of cobalt dicarbollide

    DOE Patents [OSTI]

    Hurlburt, Paul K. (Los Alamos, NM); Abney, Kent D. (Los Alamos, NM); Kinkead, Scott A. (Los Alamos, NM)

    1997-01-01T23:59:59.000Z

    A method for selectively adding chlorine, bromine, or iodine to cobalt dicarbollide anions by means of electrophilic substitution reactions. Halogens are added only to the B10 and B10' positions of the anion. The process involves use of hypohalous acid or N-halosuccinimide or gaseous chlorine in the presence of iron.

  12. Halogenation of cobalt dicarbollide

    DOE Patents [OSTI]

    Hurlburt, P.K.; Abney, K.D.; Kinkead, S.A.

    1997-05-20T23:59:59.000Z

    A method for selectively adding chlorine, bromine, or iodine to cobalt dicarbollide anions by means of electrophilic substitution reactions. Halogens are added only to the B10 and B10{prime} positions of the anion. The process involves use of hypohalous acid or N-halosuccinimide or gaseous chlorine in the presence of iron. 1 fig.

  13. Stochastic modeling of hourly dry-bulb and wet-bulb temperatures

    SciTech Connect (OSTI)

    Kline, D.E.; Woeste, F.E.

    1984-01-01T23:59:59.000Z

    A stochastic model of hourly dry-bulb and wet-bulb temperatures was developed. The periodic variations over the course of a year were estimated by least-square approximation. A multisite Markov model was used to simulate the stochastic nature of the data. These two models were combined to simulate years of hourly dry-bulb and wet-bulb temperatures.

  14. MULTIPHOTON DISSOCIATION PRODUCTS FROM HALOGENATED HYDROCARBONS

    E-Print Network [OSTI]

    Sudbo, Aa. S.

    2011-01-01T23:59:59.000Z

    FROM HALOGENATED HYDROCARBONS RECE1VED Aa. S. Sudbo, P. A.FROM HALOGENATED HYDROCARBONS LBL-6966 Aa. S. Sudbo, t P. A.

  15. Fooling Mother Nature: Forcing Flower Bulbs

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Fooling Mother Nature: Forcing Flower Bulbs for Indoor Bloom by George Graine,Virginia Cooperative Bulbs for Indoor Bloom George Graine,Virginia Cooperative Extension Master Gardener, Fairfax County, VA Introduction Have you ever wondered if it is possible to enjoy the beauty of bulbs in the middle of winter

  16. (bulb) , (1) Gas(1) Gas(1) Gas(1) Gas----saturation methodsaturation methodsaturation methodsaturation method

    E-Print Network [OSTI]

    Hong, Deog Ki

    (bulb) , . . , . . 1. . (1) Gas(1Static MethodStatic Method Isoteniscope bulb U-tube . bulb U-tube bulb . bulb . U bulb . manometer . . Isoteniscope Boling Point Method . #12;2. (1) Boiling

  17. Type of Space Bulb Type #/House Fixture Style Greenhouse #

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Type of Space Bulb Type #/House Fixture Style Greenhouse # 1 Lu 430/Lu 400 24 White box style 2 Lu No bulbs 0 N/A Seed harvest room F32 T8/TL 841 90 bulbs VIGS Room F032 /741/ECO 60 bulbs Chamber Model Bulb

  18. Consumer Light Bulb Changes: Briefing and Resources for Media...

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

    Consumer Light Bulb Changes: Briefing and Resources for Media and Retailers Consumer Light Bulb Changes: Briefing and Resources for Media and Retailers This presentation provides...

  19. The New York City Bulb Garden [Transforming the American Garden: 12 New Landscape Designs-Exhibitor

    E-Print Network [OSTI]

    Schwartz, Martha

    1986-01-01T23:59:59.000Z

    point of intersection. The bulbs selected for this schemefall and late fall. The bulbs have been selected for theiris designed for flexibility. Bulbs can be replaced and new

  20. Investigations into the Nature of Halogen Bonding Including Symmetry...

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

    into the Nature of Halogen Bonding Including Symmetry Adapted Perturbation Theory Analyses. Investigations into the Nature of Halogen Bonding Including Symmetry Adapted...

  1. 2, 14571486, 2005 Halogens in peat

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    BGD 2, 1457­1486, 2005 Halogens in peat porewater H. Biester et al. Title Page Abstract Discussions is the access reviewed discussion forum of Biogeosciences Halogens in porewater of peat bogs ­ the role of peat decomposition and dissolved organic matter H. Biester 1 , D. Selimovi´c 1 , S. Hemmerich 1

  2. 100 Prisoners and A light Bulb Yisong Song

    E-Print Network [OSTI]

    Morrow, James A.

    100 Prisoners and A light Bulb Yisong Song 1. Introduction The article represent three different protocols for solving the "100 Prisoners and a Light Bulb" riddle, including the explicit computations only a light bulb with a toggle switch. The prisoner will be able to observe the current state

  3. The Somatotopic Organization of the Olfactory Bulb in Elasmobranchs

    E-Print Network [OSTI]

    Kajiura, Stephen

    The Somatotopic Organization of the Olfactory Bulb in Elasmobranchs Tricia L. Meredith,1, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045 ABSTRACT The olfactory bulbs-olfac- tory bulbs.'' Somatotopy could provide a preadaptation which facilitated the evolution of olfactory

  4. Cellular/Molecular Detecting Activity in Olfactory Bulb Glomeruli with

    E-Print Network [OSTI]

    Newman, Eric A.

    Cellular/Molecular Detecting Activity in Olfactory Bulb Glomeruli with Astrocyte Recording Didier, Oregon 97239 In the olfactory bulb, axons of olfactory sensory neurons (OSNs) expressing the same to examine functional compartmentalization within and between olfactory bulb glomeruli. Key words: olfactory

  5. BULB: Onion-Based Measuring of OSS Communities

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    BULB: Onion-Based Measuring of OSS Communities Terhi Kilamo1 , Timo Aaltonen1 , and Teemu J. Heinim based on scarce information. In this paper a measuring model for open source commu- nities, BULB, is introduced. BULB provides a way of collecting relevant information and relates it to the well-known onion

  6. Encoding Pheromonal Signals in the Accessory Olfactory Bulb of

    E-Print Network [OSTI]

    Fee, Michale S.

    Encoding Pheromonal Signals in the Accessory Olfactory Bulb of Behaving Mice Minmin Luo,1 * Michale single neurons in the accessory olfactory bulb, a nucleusthatprocessespheromonalsignals with sources of pheromones (4, 5). Olfactory receptor neurons project to the main olfactory bulb (MOB), whose

  7. Energy efficient alternatives to halogen torchieres

    SciTech Connect (OSTI)

    Siminovitch, M.; Marr, L.; Mitchell, J.; Page, E.

    1997-03-01T23:59:59.000Z

    A series of novel energy efficient torchiere systems have been developed using compact fluorescent lamps (CFLs). These systems were studied photometrically and compared with the performance of traditional commercially available tungsten halogen sources. Gonio-photometric data and power assessments indicate that significant lighting energy savings can be obtained by utilizing CFL sources instead of standard tungsten halogen sources. This energy savings is jointly due to the higher source efficacy of the CFLs and the surprisingly poor performance of the imported 300 Watt halogen lamps. Experimental data shows that a 50 to 60 Watt CFL will effectively lumen match a variety of 300 Watt tungsten halogen sources with 5 to 10 times the efficacy. CFL torchieres have additional benefits of higher power quality and cooler lamp operating temperature, making them safer fixtures.

  8. Photodissociation Dynamics of Halogen Oxide Species 

    E-Print Network [OSTI]

    Dooley, Kristin S.

    2010-07-14T23:59:59.000Z

    The focus of this dissertation is the study of the photodissociation dynamics of halogen oxide species (XO, X = Cl, Br, I). These radical species are known to be important in stratospheric and tropospheric ozone depletion ...

  9. HELSINKI UNIVERSITY OF TECHNOLOGY ENE-47.153 Halogens, dioxins/Halogens, dioxins/furansfurans

    E-Print Network [OSTI]

    Zevenhoven, Ron

    .153 Halogens in fossil fuels (mg/kg)Halogens in fossil fuels (mg/kg) (listed as F, Cl, Br) Coal*, lignite 20 OrimulsionTM ~700 Petroleum coke, "petcoke" ~ 300 Natural gas - * Iodine 0.5 - 1.5 mg/kg #12;HELSINKI-related corrosion #3 Corrosion rateCorrosion rate versusversus chlorine in coalchlorine in coal #12;HELSINKI

  10. Chemical Dependencies of Learning in the Rabbit Olfactory Bulb: Acquisition of the Transient Spatial Pattern Chance Depends on Norepinephrine

    E-Print Network [OSTI]

    Gray, Charles M; Freeman, Walter J III; Skinner, James E

    1986-01-01T23:59:59.000Z

    of neurons in the olfactory bulb following prolonged odorforcbrain (3): Olfactory bulb. anterior olfactory nucleus.39;thc rat olfactory bulb (2): Fluorescnce histochemical.

  11. Jacob P. Brenner Design Specifications for Wet-Bulb Aspirator Apparatus

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    Jacob P. Brenner Thesis: Design Specifications for Wet-Bulb Aspirator Apparatus Project Description the concentration of water vapor in the air is the wet-bulb temperature. The wet-bulb temperature along with the dry-bulb for the testing of HVAC&R equipment. The focus of this research is on the accurate measurement of the wet-bulb

  12. Consumer Light Bulb Changes: Briefing and Resources for Media...

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

    flux") - CFL: Compact Fluorescent Lamp: The curly fluorescent bulbs - LED: Light Emitting Diode: more recently emerging technology, also called "solid state lighting" as it is...

  13. How Energy-Efficient Light Bulbs Compare with Traditional Incandescent...

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

    used light fixtures or bulbs with models that have earned the ENERGY STAR, you can save 75 each year. Compared to traditional incandescents, energy-efficient lightbulbs...

  14. SuperBulbs Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern ILSunseeker Energy Holding AG JumpSunways AGSuperBulbs Inc

  15. Physiological properties and factors affecting migration of neural precursor cells in the adult olfactory bulb

    E-Print Network [OSTI]

    Darcy, Daniel Paul

    2007-01-01T23:59:59.000Z

    neurons in the olfactory bulb." J Neurosci 26(41): 10508-in the olfactory bulb." The Journal of comparative neurologycells to the olfactory bulb." J Neurosci 21(21): 8505-13.

  16. Crystallographic studies on enzymatic halogenation of natural products

    E-Print Network [OSTI]

    Blasiak, Leah Cameron

    2008-01-01T23:59:59.000Z

    Halogenated natural products are common and serve roles as hormones, pesticides, antibiotics, and anti-tumor agents. The incorporation of a halogen atom into an organic scaffold can tune the molecule's potency and selectivity, ...

  17. anesthesiques halogenes pendant: Topics by E-print Network

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

    are considered. We predict the major alkali and halogen species in a Pele-like volcanic gas and the major alklai and halogen condensates. We also model disequilibrium chemistry...

  18. active halogen species: Topics by E-print Network

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

    are considered. We predict the major alkali and halogen species in a Pele-like volcanic gas and the major alklai and halogen condensates. We also model disequilibrium chemistry...

  19. Method and apparatus for low temperature destruction of halogenated hydrocarbons

    DOE Patents [OSTI]

    Reagen, William Kevin (Stillwater, MN); Janikowski, Stuart Kevin (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A method and apparatus for decomposing halogenated hydrocarbons are provided. The halogenated hydrocarbon is mixed with solvating agents and maintained in a predetermined atmosphere and at a predetermined temperature. The mixture is contacted with recyclable reactive material for chemically reacting with the recyclable material to create dehalogenated hydrocarbons and halogenated inorganic compounds. A feature of the invention is that the process enables low temperature destruction of halogenated hydrocarbons.

  20. Halogenation of Imidazolium Ionic Liquids. Thermodynamics Perspective

    E-Print Network [OSTI]

    Chaban, Vitaly V

    2015-01-01T23:59:59.000Z

    Imidazolium cations are promising for anion exchange membranes, and electrochemical applications and gas capture. They can be chemically modified in many ways including halogenation. Halogenation possibilities of the imidazole ring constitute a particular interest. This work investigates fluorination and chlorination reactions of all symmetrically non-equivalent sites of the imidazolium cation. Halogenation of all carbon atoms is thermodynamically permitted. Out of these, the most favorable site is the first methylene group of the alkyl chain. In turn, the least favorable site is carbon of the imidazole ring. Temperature dependence of enthalpy, entropy, and Gibbs free energy at 1 bar is discussed. The reported results provide an important guidance in functionalization of ionic liquids in search of task-specific compounds.

  1. Modeling the wet bulb globe temperature using standard meteorological measurements.

    SciTech Connect (OSTI)

    Liljegren, J. C.; Carhart, R. A.; Lawday, P.; Tschopp, S.; Sharp, R.; Decision and Information Sciences

    2008-10-01T23:59:59.000Z

    The U.S. Army has a need for continuous, accurate estimates of the wet bulb globe temperature to protect soldiers and civilian workers from heat-related injuries, including those involved in the storage and destruction of aging chemical munitions at depots across the United States. At these depots, workers must don protective clothing that increases their risk of heat-related injury. Because of the difficulty in making continuous, accurate measurements of wet bulb globe temperature outdoors, the authors have developed a model of the wet bulb globe temperature that relies only on standard meteorological data available at each storage depot for input. The model is composed of separate submodels of the natural wet bulb and globe temperatures that are based on fundamental principles of heat and mass transfer, has no site-dependent parameters, and achieves an accuracy of better than 1 C based on comparisons with wet bulb globe temperature measurements at all depots.

  2. Retention of Halogens in Waste Glass

    SciTech Connect (OSTI)

    Hrma, Pavel R.

    2010-05-01T23:59:59.000Z

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ?100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  3. A new maintenance friendly concept for bulb type generators

    SciTech Connect (OSTI)

    Scheidl, W.

    1998-07-01T23:59:59.000Z

    Bulb type generators in the rating range up to 15 MW are in a severe competition with geared up machines which operate at much higher speed and are therefore smaller and cheaper. Up to now the conventional bulb type generator in the standard design as it is used on several rivers in Austria and many other countries was not so economic in the lower rating range. A new and maintenance friendly concept for the bulb type generator design especially for these lower rating range ended in a more economic solution and is now able to compete with the geared up machines.

  4. Process for removal of hydrogen halides or halogens from incinerator gas

    DOE Patents [OSTI]

    Huang, H.S.; Sather, N.F.

    1987-08-21T23:59:59.000Z

    A process for reducing the amount of halogens and halogen acids in high temperature combustion gas and through their removal, the formation of halogenated organics at lower temperatures, with the reduction being carried out electrochemically by contacting the combustion gas with the negative electrode of an electrochemical cell and with the halogen and/or halogen acid being recovered at the positive electrode.

  5. Oxidation of hydrogen halides to elemental halogens

    DOE Patents [OSTI]

    Rohrmann, Charles A. (Kennewick, WA); Fullam, Harold T. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A process for oxidizing hydrogen halides having substantially no sulfur impurities by means of a catalytically active molten salt is disclosed. A mixture of the subject hydrogen halide and an oxygen bearing gas is contacted with a molten salt containing an oxidizing catalyst and alkali metal normal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen and substantially free of sulfur oxide gases.

  6. Direct conversion of halogen-containing wastes to borosilicate glass

    SciTech Connect (OSTI)

    Forsberg, C.W.; Beahm, E.C.; Rudolph, J.C.

    1996-12-09T23:59:59.000Z

    Glass has become a preferred waste form worldwide for radioactive wastes: however, there are limitations. Halogen-containing wastes can not be converted to glass because halogens form poor-quality waste glasses. Furthermore, halides in glass melters often form second phases that create operating problems. A new waste vitrification process, the Glass Material Oxidation and dissolution System (GMODS), removes these limitations by converting halogen-containing wastes into borosilicate glass and a secondary, clean, sodium-halide stream.

  7. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect (OSTI)

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01T23:59:59.000Z

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward the goal of developing a portable test kit for screening halogenated VOCs in the field.

  8. Radiation Dose-Volume Effects and the Penile Bulb

    SciTech Connect (OSTI)

    Roach, Mack, E-mail: mroach@radonc.ucsf.ed [Department of Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Nam, Jiho [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Gagliardi, Giovanna [Department of Medical Physics, Karolinska University Hospital and Karolinska Institutet, Stockholm (Sweden); El Naqa, Issam; Deasy, Joseph O. [Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, St. Louis, MO (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)

    2010-03-01T23:59:59.000Z

    The dose, volume, and clinical outcome data for penile bulb are reviewed for patients treated with external-beam radiotherapy. Most, but not all, studies find an association between impotence and dosimetric parameters (e.g., threshold doses) and clinical factors (e.g., age, comorbid diseases). According to the data available, it is prudent to keep the mean dose to 95% of the penile bulb volume to <50 Gy. It may also be prudent to limit the D70 and D90 to 70 Gy and 50 Gy, respectively, but coverage of the planning target volume should not be compromised. It is acknowledged that the penile bulb may not be the critical component of the erectile apparatus, but it seems to be a surrogate for yet to be determined structure(s) critical for erectile function for at least some techniques.

  9. Text-Alternative Version: L Prize™: The Race for Super Efficient Light Bulbs

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the L Prize™: The Race for Super Efficient Light Bulbs webcast.

  10. Luminous "Dark" Halos

    E-Print Network [OSTI]

    Mark A. Walker

    2000-08-07T23:59:59.000Z

    Several lines of evidence suggest that cold, dense gas clouds make a substantial contribution to the total mass of dark halos. If so then physical collisions between clouds must occur; these cause strong, radiative shocks to propagate through the cold gas, with the startling implication that all ``dark'' halos must be luminous. The expected luminosity is a strong function of halo velocity dispersion, and should contribute a significant fraction of the observed X-ray emission from clusters of galaxies, if dark halos are predominantly made of cold gas. Existing data do not exclude this possibility; indeed two particular expectations of the luminous-halo model are borne out in the X-ray data, and thus give support to the cold-cloud dark matter model. First we find a luminosity-temperature correlation of the form L proportional to T to the power 11/4, as seen in recent analyses of cluster samples. Secondly the anticipated spectra have substantially more power at low energies than isothermal bremsstrahlung spectra, and might account for the observed ``excess'' EUV emission seen from some clusters. The successes of the luminous-halo model are particularly remarkable because the theory has no free parameters or ad hoc elements. The model can be tested by the X-ray satellite Chandra, which should resolve the Virgo cluster into 10,000 point-like, transient X-ray sources. Non-detection of any such sources by Chandra can constrain the contribution of cold gas clouds to below 1% of the total matter density in the Universe, assuming Virgo to be representative.

  11. Modlisation des rythmes rapides bta et gamma du bulbe olfactif Nicolas Fourcaud-Trocm

    E-Print Network [OSTI]

    Boyer, Edmond

    Modélisation des rythmes rapides bêta et gamma du bulbe olfactif Nicolas Fourcaud-Trocmé Université mammifères, la première zone corticale traitant l'information olfactive est le bulbe olfactif (BO). Le codage anesthésié. MOTS-CLES bulbe olfactif, oscillations, bêta, gamma, modèle 1. Introduction En neurosciences, les

  12. Onion ipmPIPE -Diagnostic Pocket Series Bulb Growth Stages of Onion (Allium cepa L.)

    E-Print Network [OSTI]

    Pappu, Hanu R.

    Onion ipmPIPE - Diagnostic Pocket Series Bulb Growth Stages of Onion (Allium cepa L.) Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 6 Fig 7 Fig 8 Allium Type: Fresh Market and Storage Onion Both pre- and post-bulb planting (seeds, transplants, sets). Pre-Bulb Growth Stages 1 ­ radical and flag leaf emergence (10-30 days

  13. Amlioration des plantes Production de bulbes in vitro et de novo

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Amélioration des plantes Production de bulbes in vitro et de novo à partir de tissus de tiges à bulbes, 29260 Ploudaniel; 2 Université Blaise Pascal, laboratoire de physiologie et génétique décembre 1992) Résumé — L'obtention de novo de bulbes in vitro est possible chez la tulipe dans un

  14. Behavioral/Systems/Cognitive Olfactory Bulb Gamma Oscillations Are Enhanced with

    E-Print Network [OSTI]

    Kopell, Nancy

    Behavioral/Systems/Cognitive Olfactory Bulb Gamma Oscillations Are Enhanced with Task Demands.However,thereisstillnodirectevidencethatsuchoscillationsareintrinsicallyalteredinintactsystems to aid in stimulus disambiguation. Here we show that gamma oscillatory power in the rat olfactory bulb; sensory acuity; beta oscillations; olfactory bulb; piriform (pyriform) Introduction The chemotopic

  15. Dendrodendritic Inhibition in the Olfactory Bulb Is Driven by NMDA Receptors

    E-Print Network [OSTI]

    Betz, William J.

    Dendrodendritic Inhibition in the Olfactory Bulb Is Driven by NMDA Receptors Nathan E. Schoppa,1 J synapses between mitral and granule cells in the rat olfactory bulb. In whole-cell patch-clamp recordings in bulb slices, stimulation of mitral cells elicited slowly decaying, GABAA receptor-mediated reciprocal

  16. THE LIGHT BULB PROBLEM 1 Ramamohan Paturi2 Sanguthevar Rajasekaran3 John Reif3

    E-Print Network [OSTI]

    Rajasekaran, Sanguthevar

    THE LIGHT BULB PROBLEM 1 Ramamohan Paturi2 Sanguthevar Rajasekaran3 John Reif3 Univ. of California Title: The Light Bulb Problem Corresponding Author: Ramamohan Paturi Department of Computer Science Mail correlational learning problem due to L. G. Valiant, 1985 and 1988: We have a sequence of n random light bulbs

  17. ACTION DE L'ABLATION DES BULBES OLFACTIFS SUR LES MCANISMES DE LA REPRODUCTION

    E-Print Network [OSTI]

    Boyer, Edmond

    ACTION DE L'ABLATION DES BULBES OLFACTIFS SUR LES MÉCANISMES DE LA REPRODUCTION CHEZ LA TRUIE J. P Recheyches zoolechniques, Jouy-en-Josas (Seine et Oise). SOMMAIRE L'ablation chirurgicale des bulbes involution utérine. L'ablation totale des bulbes olfactifs semble donc perturber la décharge des hormones

  18. STABLE FREQUENCY RESPONSE TO VARYING STIMULUS INTENSITY IN A MODEL OF THE RAT OLFACTORY BULB

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    STABLE FREQUENCY RESPONSE TO VARYING STIMULUS INTENSITY IN A MODEL OF THE RAT OLFACTORY BULB Thomas Neurosciences et Systèmes sensoriels, CNRS UMR 5020, Lyon, France ABSTRACT In the rat olfactory bulb (OB), fast. Introduction The rat olfactory bulb (OB) is a rich and complex sensory processing system that shows stimulus

  19. THE LIGHT BULB PROBLEM 1 Ramamohan Paturi2 Sanguthevar Rajasekaran3 John Reif3

    E-Print Network [OSTI]

    Rajasekaran, Sanguthevar

    THE LIGHT BULB PROBLEM 1 Ramamohan Paturi2 Sanguthevar Rajasekaran3 John Reif3 Univ. of California, San Diego Univ. of Pennsylvania Duke University 1 #12;Running Title: The Light Bulb Problem, 1985 and 1988: We have a sequence of n random light bulbs each of which is either on or off with equal

  20. Editorial Focus Fish Smell. Focus on "Odorant Specificity of Single Olfactory Bulb Neurons

    E-Print Network [OSTI]

    Stephens, Jacqueline

    Editorial Focus Fish Smell. Focus on "Odorant Specificity of Single Olfactory Bulb Neurons to Amino bulb, or antennal lobe. The precise nature of these odor features is yet to be determined for the most of this type in the fish, precise subclasses of olfactory bulb neurons for coding biologically significant

  1. Dendrodendritic Inhibition and Simulated Odor Responses in a Detailed Olfactory Bulb Network Model

    E-Print Network [OSTI]

    Feng, Jianfeng

    Dendrodendritic Inhibition and Simulated Odor Responses in a Detailed Olfactory Bulb Network Model responses in a detailed olfac- tory bulb network model. J Neurophysiol 90: 1921­1935, 2003. First published May 7, 2003; 10.1152/jn.00623.2002. In the olfactory bulb, both the spatial distribution

  2. Neuronal representation of odourants in the olfactory bulb of Xenopus laevis tadpoles

    E-Print Network [OSTI]

    Neuronal representation of odourants in the olfactory bulb of Xenopus laevis tadpoles Dirk Czesnik representation, olfactory bulb Abstract When an odourant enters the nose, olfactory receptor neurons (ORNs) convey information about it to the olfactory bulb (OB), where this information is processed and where

  3. Rhythm sequence through the olfactory bulb layers during the time window of a respiratory cycle

    E-Print Network [OSTI]

    Roux, Stephane

    Rhythm sequence through the olfactory bulb layers during the time window of a respiratory cycle 07, France Keywords: LFP, olfactory bulb, oscillations, rat, synchronization Abstract The mammalian olfactory bulb is characterized by prominent oscillatory activity of its local ®eld potentials. Breathing

  4. Structure of lateral inhibition in an olfactory bulb Andrew Davison, Jianfeng Feng, and David Brown

    E-Print Network [OSTI]

    Feng, Jianfeng

    Structure of lateral inhibition in an olfactory bulb model Andrew Davison, Jianfeng Feng, and David Abstract. It has been shown that mutual lateral inhibition of the projection neurones in the olfactory bulb, mediated by interneurones, serves to tune the representation of odours in the bulb and reduce the overlap

  5. How Many CASTLE Bulbs Would You Need To Match the Brightness of the Sun?

    E-Print Network [OSTI]

    Collar, Juan I.

    How Many CASTLE Bulbs Would You Need To Match the Brightness of the Sun? = × ? Please do all million miles), so if we were to try to build the Sun out of light bulbs, we'd need a bunch! But, how many objects: the Sun, and a CASTLE light bulb. What do we mean by "brightness?" The electromagnetic (EM

  6. Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury

    E-Print Network [OSTI]

    Jia, Songtao

    Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury February 2008 Why should people use CFLs? Switching from traditional light bulbs to CFLs is an effective light bulbs, last up to 10 times longer, cost little up front, and provide a quick return on investment

  7. THE EFFECT OF SNOWPACK WARMING ON THE STRESS BULB BELOW A SKIER Thomas Exner *

    E-Print Network [OSTI]

    Jamieson, Bruce

    THE EFFECT OF SNOWPACK WARMING ON THE STRESS BULB BELOW A SKIER Thomas Exner * Dept. of Geoscience exist to quantify or validate the temperature effect on the stress bulb below a skier. In this study we periods. Increasing temperatures of the near-surface layers altered the shape of the stress bulb, but so

  8. Labeling energy cost on light bulbs lowers implicit discount rates Jihoon Min a

    E-Print Network [OSTI]

    Michalek, Jeremy J.

    Analysis Labeling energy cost on light bulbs lowers implicit discount rates Jihoon Min a , Inês L considerably. To quantify the influence of factors that drive consumer choices for light bulbs, we conducted incandescent bulbs. About half of the total lighting service (in terms of lumens) was provided by incandes

  9. Linear programming applied to the ower sector: a Gladiolus bulb production case study

    E-Print Network [OSTI]

    Dragoti-Çela, Eranda

    Linear programming applied to the ¯ower sector: a Gladiolus bulb production case study Jose representative Brazilian bulb growing and trading company's decision making process, during the Gladiolus production planning activity. The pertinent LP model was focused on client's bulb requests to be attended

  10. THE LIGHT BULB PROBLEM 1 Ramamohan Paturi 2 Sanguthevar Rajasekaran 3 John Reif 3

    E-Print Network [OSTI]

    Reif, John H.

    THE LIGHT BULB PROBLEM 1 Ramamohan Paturi 2 Sanguthevar Rajasekaran 3 John Reif 3 Univ. of California, San Diego Univ. of Pennsylvania Duke University 1 #12; Running Title: The Light Bulb Problem, 1985 and 1988: We have a sequence of n random light bulbs each of which is either on or o# with equal

  11. Photoperiod Mediated Changes in Olfactory Bulb Neurogenesis and Olfactory Behavior in Male White-

    E-Print Network [OSTI]

    Nelson, Randy J.

    Photoperiod Mediated Changes in Olfactory Bulb Neurogenesis and Olfactory Behavior in Male White to long day lengths (LD) and short day lengths (SD) for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology

  12. fMRI visualisation of transient activations in the rat olfactory bulb using short odour stimulations

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    fMRI visualisation of transient activations in the rat olfactory bulb using short odour in the olfactory bulb OB displays both spatial and temporal organization. The difficulty when assessing spatio of the olfactory bulb (OB). Hence, in this structure, the identity of odorants is associated with a unique spatial

  13. Calcium Influx through NMDA Receptors Directly Evokes GABA Release in Olfactory Bulb Granule Cells

    E-Print Network [OSTI]

    Strowbridge, Ben

    Calcium Influx through NMDA Receptors Directly Evokes GABA Release in Olfactory Bulb Granule Cells, Case Western Reserve University, Cleveland, Ohio 44106-4975 Recurrent inhibition in olfactory bulb on the activation of NMDA receptors. Using whole-cell recordings from rat olfactory bulb slices, we now show

  14. Free Energy Efficiency Kit includes CFL light bulbs,

    E-Print Network [OSTI]

    Rose, Annkatrin

    Free Energy Efficiency Kit Kit includes CFL light bulbs, spray foam, low-flow shower head, and more for discounted energy assessments. FREE HOME ENERGY EFFICIENCY SEMINAR N e w R i ver L i g ht & Pow e r a n d W! Building Science 101 Presentation BPI Certified Building Professionals will present home energy efficiency

  15. Metal halogen battery construction with improved technique for producing halogen hydrate

    DOE Patents [OSTI]

    Fong, Walter L. (Royal Oak, MI); Catherino, Henry A. (Rochester, MI); Kotch, Richard J. (Mt. Clemens, MI)

    1983-01-01T23:59:59.000Z

    An improved electrical energy storage system comprising, at least one cell having a positive electrode and a negative electrode separated by aqueous electrolyte, a store means wherein halogen hydrate is formed and stored as part of an aqueous material having a liquid level near the upper part of the store, means for circulating electrolyte through the cell, conduit means for transmitting halogen gas formed in the cell to a hydrate forming apparatus associated with the store, said hydrate forming apparatus including, a pump to which there is introduced quantities of the halogen gas and chilled water, said pump being located in the store and an outlet conduit leading from the pump and being substantially straight and generally vertically disposed and having an exit discharge into the gas space above the liquid level in the store, and wherein said hydrate forming apparatus is highly efficient and very resistant to plugging or jamming. The disclosure also relates to an improved method for producing chlorine hydrate in zinc chlorine batteries.

  16. Shapes of dark matter halos

    E-Print Network [OSTI]

    James S. Bullock

    2001-06-21T23:59:59.000Z

    I present an analysis of the density shapes of dark matter halos in LCDM and LWDM cosmologies. The main results are derived from a statistical sample of galaxy-mass halos drawn from a high resolution LCDM N-body simulation. Halo shapes show significant trends with mass and redshift: low-mass halos are rounder than high mass halos, and, for a fixed mass, halos are rounder at low z. Contrary to previous expectations, which were based on cluster-mass halos and non-COBE normalized simulations, LCDM galaxy-mass halos at z=0 are not strongly flattened, with short to long axis ratios of s = 0.70 +/- 0.17. I go on to study how the shapes of individual halos change when going from a LCDM simulation to a simulation with a warm dark matter power spectrum (LWDM). Four halos were compared, and, on average, the WDM halos are more spherical than their CDM counterparts (s =0.77 compared to s = 0.71). A larger sample of objects will be needed to test whether the trend is significant.

  17. Photochemical reductive elimination of halogen from transition metal complexes

    E-Print Network [OSTI]

    Cook, Timothy R. (Timothy Raymond), 1982-

    2010-01-01T23:59:59.000Z

    This thesis is focused on the synthesis and study of transition metal complexes that undergo halogen elimination when irradiated with UV and visible light. This chemistry is relevant for solar energy storage schemes in ...

  18. Influence du poids et de la densit de plantation des bulbes d'chalote sur les caractristiques de

    E-Print Network [OSTI]

    Boyer, Edmond

    Influence du poids et de la densité de plantation des bulbes d'échalote sur les caractéristiques de la récolte et la prolificité des bulbes-fils Joseph COHAT Corentin TROMEUR LN.R.A., Station damélioration de la Pomme de terre et des Plantes à bulbes, F 29207 Landerneau RÉSUMÉ Des bulbes d'échalote de

  19. Influence d'un trempage des bulbes dans une solution d'acide 2-chloro thylphosphonique (thphon) sur la

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence d'un trempage des bulbes dans une solution d'acide 2-chloro éthylphosphonique (éthéphon la Pomme de terre et des Plantes à bulbes, F 29207 Landerneau RÉSUMÉ Le trempage des bulbes d augmentation du pourcentage de floraison. Ceci résulte d'une diminution du nombre de bulbes qui Ethéphon

  20. Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

    DOE Patents [OSTI]

    Goodman, Mark M. (Atlanta, GA); Faraj, Bahjat (Lithonia, GA)

    1999-01-01T23:59:59.000Z

    Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

  1. Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

    DOE Patents [OSTI]

    Goodman, M.M.; Faraj, B.

    1999-07-06T23:59:59.000Z

    Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

  2. Treatment of halogen-containing waste and other waste materials

    DOE Patents [OSTI]

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1997-03-18T23:59:59.000Z

    A process is described for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes. 3 figs.

  3. Treatment of halogen-containing waste and other waste materials

    DOE Patents [OSTI]

    Forsberg, Charles W. (Oak Ridge, TN); Beahm, Edward C. (Oak Ridge, TN); Parker, George W. (Concord, TN)

    1997-01-01T23:59:59.000Z

    A process for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes.

  4. Metal halogen battery system with multiple outlet nozzle for hydrate

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-06-21T23:59:59.000Z

    A metal halogen battery system, including at least one cell having a positive electrode and a negative electrode contacted by aqueous electrolyte containing the material of said metal and halogen, store means whereby halogen hydrate is formed and stored as part of an aqueous material, means for circulating electrolyte through the cell and to the store means, and conduit means for transmitting halogen gas formed in the cell to a hydrate former whereby the hydrate is formed in association with the store means, said store means being constructed in the form of a container which includes a filter means, said filter means being inoperative to separate the hydrate formed from the electrolyte, said system having, a hydrate former pump means associated with the store means and being operative to intermix halogen gas with aqueous electrolyte to form halogen hydrate, said hydrate former means including, multiple outlet nozzle means connected with the outlet side of said pump means and being operative to minimize plugging, said nozzle means being comprised of at least one divider means which is generally perpendicular to the rotational axes of gears within the pump means, said divider means acting to divide the flow from the pump means into multiple outlet flow paths.

  5. Estimating Wet Bulb Globe Temperature Using Standard Meteorological Measurements

    SciTech Connect (OSTI)

    Hunter, C.H.

    1999-11-18T23:59:59.000Z

    The heat stress management program at the Department of Energy''s Savannah River Site (SRS) requires implementation of protective controls on outdoor work based on observed values of wet bulb globe temperature (WBGT). To ensure continued compliance with heat stress program requirements, a computer algorithm was developed which calculates an estimate of WBGT using standard meteorological measurements. In addition, scripts were developed to generate a calculation every 15 minutes and post the results to an Intranet web site.

  6. Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) in the Norwestern Atlantic

    E-Print Network [OSTI]

    Pangallo, Kristin C

    2009-01-01T23:59:59.000Z

    Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) are a distinctive class of marine organic compounds. They are naturally produced, they have a unique carbon structure, they are highly halogenated, and they bioaccumulate in ...

  7. Solid-State Halogen Atom Source for Chemical Dynamics and Etching...

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

    Halogen Atom Source for Chemical Dynamics and Etching. Solid-State Halogen Atom Source for Chemical Dynamics and Etching. Abstract: We describe a solid state Br atom source for...

  8. Development of Diagnostic Rules for a Dry Bulb Economizer Mixed Air Loop

    E-Print Network [OSTI]

    Underwood, D.

    1990-01-01T23:59:59.000Z

    knowledge base for a two fan variable air volume (VAV) air handling unit. Rules for the mixed air loop with a dry bulb economizer are presented....

  9. DOE Requires Westinghouse to Cease Sales of Two Light Bulb Models...

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

    against Westinghouse Lighting Corporation, the company must cease sales of two light bulb models - medium based CFL basic model 15GLOBE652 (Westinghouse product code 3800400)...

  10. E-Print Network 3.0 - agents anesthesiques halogenes Sample Search...

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

    Chemistry 17 Incompatible Chemicals -Partial list Chemical Incompatibilities Summary: , carbon tetrachloride or other chlorinated hydrocarbons, carbon dioxide, halogens Ammonia...

  11. Symmetric and asymmetric halogen-containing metallocarboranylporphyrins and uses thereof

    DOE Patents [OSTI]

    Miura, Michiko; Wu, Haitao

    2013-05-21T23:59:59.000Z

    The present invention is directed to low toxicity boronated compounds and methods for their use in the treatment, visualization, and diagnosis of tumors. More specifically, the present invention is directed to low toxicity halogenated, carborane-containing 5,10,15,20-tetraphenylporphyrin compounds and methods for their use particularly in boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) for the treatment of tumors of the brain, head and neck, and surrounding tissue. The invention is also directed to using these halogenated, carborane-containing tetraphenylporphyrin compounds in methods of tumor imaging and/or diagnosis such as MRI, SPECT, or PET.

  12. Symmetry Projected Density Functional Theory and Neutron Halo’s

    E-Print Network [OSTI]

    unknown authors

    The appearance of halo phenomena near the drip line nuclei has challenged our traditional understanding of the nuclei as an incompressible charged liquid drop and extended nuclear physics to low density and inhomogeneous system, where the coupling to the continuum has to be treated in a consistent way. Recently Relativistic Hartree Bogoliubov (RHB) theory in the continuum has been applied successfully to the description of halo phenomena in light and medium heavy nuclei [1, 2, 3]. This theory provides a self-consistent treatment of pairing correlation in the presence of the continuum and allows a microscopic description of halo phenomena in the framework of density functional theory. Essential conditions for the formation of a neutron halo have been found: (a) the Fermi surface of the neutrons has to

  13. Full Spectrum Light Therapy Full spectrum light bulbs are said to not only improve mood, but also

    E-Print Network [OSTI]

    Bates, Rebecca A.

    Full Spectrum Light Therapy Full spectrum light bulbs are said to not only improve mood, but also spectrum light bulbs produce light that is seen by the human eye in a bluish-white tint. Where is full

  14. Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered a blackbody radiator.

    E-Print Network [OSTI]

    Kioussis, Nicholas

    . 1 Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered frequency is that of infrared electromagnetic radiation, the light bulb radiates more energy in the infrared

  15. Process for oxidation of hydrogen halides to elemental halogens

    DOE Patents [OSTI]

    Lyke, Stephen E. (Middleton, WI)

    1992-01-01T23:59:59.000Z

    An improved process for generating an elemental halogen selected from chlorine, bromine or iodine, from a corresponding hydrogen halide by absorbing a molten salt mixture, which includes sulfur, alkali metals and oxygen with a sulfur to metal molar ratio between 0.9 and 1.1 and includes a dissolved oxygen compound capable of reacting with hydrogen halide to produce elemental halogen, into a porous, relatively inert substrate to produce a substrate-supported salt mixture. Thereafter, the substrate-supported salt mixture is contacted (stage 1) with a hydrogen halide while maintaining the substrate-supported salt mixture during the contacting at an elevated temperature sufficient to sustain a reaction between the oxygen compound and the hydrogen halide to produce a gaseous elemental halogen product. This is followed by purging the substrate-supported salt mixture with steam (stage 2) thereby recovering any unreacted hydrogen halide and additional elemental halogen for recycle to stage 1. The dissolved oxygen compound is regenerated in a high temperature (stage 3) and an optical intermediate temperature stage (stage 4) by contacting the substrate-supported salt mixture with a gas containing oxygen whereby the dissolved oxygen compound in the substrate-supported salt mixture is regenerated by being oxidized to a higher valence state.

  16. Method for selective dehalogenation of halogenated polyaromatic compounds

    DOE Patents [OSTI]

    Farcasiu, Malvina (Pittsburgh, PA); Petrosius, Steven C. (Library, PA)

    1994-01-01T23:59:59.000Z

    A method for dehalogenating halogenated polyaromatic compounds is provided wherein the polyaromatic compounds are mixed with a hydrogen donor solvent and a carbon catalyst in predetermined proportions, the mixture is maintained at a predetermined pressure, and the mixture is heated to a predetermined temperature and for a predetermined time.

  17. Olfactory deprivation increases dopamine D2 receptor density in the rat olfactory bulb

    SciTech Connect (OSTI)

    Guthrie, K.M.; Pullara, J.M.; Marshall, J.F.; Leon, M. (University of California, Irvine (USA))

    1991-05-01T23:59:59.000Z

    Unilateral olfactory deprivation during postnatal development results in significant anatomical and neurochemical changes in the deprived olfactory bulb. Perhaps the most dramatic neurochemical change is the loss of dopaminergic expression by neurons of the glomerular region. The authors describe here the effects of early olfactory deprivation on other elements of the bulb dopaminergic system, namely the dopamine receptors of the olfactory bulb. Rat pups had a single naris occluded on postnatal day 2 (PN2). On PN20 or PN60, animals were sacrificed and the bulbs were examined for catecholamine levels or D2 and D1 dopamine receptor binding. Receptor densities were quantified by in vitro autoradiography using the tritiated antagonists spiperone (D2) and SCH23390 (D1). Dopamine uptake sites were similarly examined using tritiated mazindol. No significant specific labeling of D1 or mazindol sites was observed in the olfactory bulbs of control or experimental animals at either age. Normal animals displayed prominent labeling of D2 sites in the glomerular and nerve layers. After 60 days of deprivation, deprived bulbs exhibited an average increase in D2 receptor density of 32%. As determined by Scatchard analysis, the mean values for Kd and Bmax were 0.134 nM and 293 fmol/mg protein in normal bulbs, and 0.136 nM and 403 fmol/mg protein in deprived bulbs. The results suggest that, as in the neostriatum, dopamine depletion in the olfactory bulb leads to an upregulation of D2 receptor sites. This change may represent an attempt by the system to adapt neurochemically to reduced dopaminergic activity and thereby maintain bulb function.

  18. Influence des conditions de conservation des bulbes d'chalote (Allium cepa L. var. aggregatum) sur leur

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence des conditions de conservation des bulbes d'échalote (Allium cepa L. var. aggregatum) sur leur levée Joseph COHAT LN.R.A., Station d'Amélioration de la Pomme de terre & des Plantes à bulbes, F 29207 Landerneau RÉSUMÉ Les bulbes d'échalote de Jersey (type demi-longue) sont dormants au moment de la

  19. A Bit About Bulbs Night temperatures are cool, the air is almost crisp. The vegetable harvest is tapering

    E-Print Network [OSTI]

    New Hampshire, University of

    A Bit About Bulbs Night temperatures are cool, the air is almost crisp. The vegetable harvest! There is always something to do, and right now is the time to plant spring-flowering bulbs. Whether your preference is for naturalized or formal bulb plantings, on a small or large scale, keep kinds and colors

  20. Impairment of Neurogensis in the Olfactory Bulb of Transgenic Mice Overexpressing Human Wildtype Alpha Synuclein Under the Thy-1 Promoter

    E-Print Network [OSTI]

    Allman, John M.

    Impairment of Neurogensis in the Olfactory Bulb of Transgenic Mice Overexpressing Human Wildtype, cortex and olfactory bulb (Rockenstein et al., 2002). These mice demonstrate early and progressive motor by olfactory ensheathing glia, and eventually reach the olfactory bulb (Gritti et al., 2002). Recent studies

  1. Dynamical Mechanisms of Odor Processing in Olfactory Bulb Mitral Cells Daniel B. Rubin and Thomas A. Cleland

    E-Print Network [OSTI]

    Cleland, Thomas A.

    Dynamical Mechanisms of Odor Processing in Olfactory Bulb Mitral Cells Daniel B. Rubin and Thomas A- nisms of odor processing in olfactory bulb mitral cells. J Neuro- physiol 96: 555­568, 2006. First, conductance-based compartmental model of olfactory bulb mitral cells that exhibits the complex dynamical

  2. Ordered progression of nematogenesis from stem cells through differentiation stages in the tentacle bulb of Clytia hemisphaerica (Hydrozoa, Cnidaria)

    E-Print Network [OSTI]

    Gibson, Matt

    bulb of Clytia hemisphaerica (Hydrozoa, Cnidaria) Elsa Denker, Michaël Manuel, Lucas Leclère, Hervé Le of the tentacle bulb, a specialized swelling at the tentacle base. Analysis by a variety of light and electron-temporal characteristics are markedly more ordered. The tentacle bulb nematogenic ectoderm (TBE) was found to be polarized

  3. Stability of fast oscillations in mammalian olfactory bulb: experiment and modeling Nicolas Fourcaud-Trocmea,b,c,d,

    E-Print Network [OSTI]

    Voegtlin, Thomas

    Stability of fast oscillations in mammalian olfactory bulb: experiment and modeling Nicolas Cortex, Vandoeuvre-les-Nancy, F-54506, France Abstract In the rat olfactory bulb (OB), fast oscillations observed stability of the oscillatory regimes. Keywords: olfactory bulb, beta oscillations, gamma

  4. Odor vapor pressure and quality modulate local field potential oscillatory patterns in the olfactory bulb of the

    E-Print Network [OSTI]

    Roux, Stephane

    in the olfactory bulb of the anesthetized rat Tristan Cenier,1 Corine Amat,1 Philippe Litaudon,1 Samuel Garcia,1 potentials, molecular features, olfactory bulb, oscillations, respiratory cycle Abstract A central question-temporal pattern of activation in the olfactory bulb (OB), in both glomerular and mitral cell layers. Mitral

  5. Odor recognition and segmentation by coupled olfactory bulb and cortical networks

    E-Print Network [OSTI]

    Li, Z; Li, Zhaoping; Hertz, John

    1999-01-01T23:59:59.000Z

    We present a model of a coupled system of the olfactory bulb and cortex. Odor inputs to the epithelium are transformed to oscillatory bulbar activities. The cortex recognizes the odor by resonating to the bulbar oscillating pattern when the amplitude and phase patterns from the bulb match an odor memory stored in the intracortical synapses. We assume a cortical structure which transforms the odor information in the oscillatory pattern to a slow DC feedback signal to the bulb. This feedback suppresses the bulbar response to the pre-existing odor, allowing subsequent odor objects to be segmented out for recognition.

  6. LACKEY, PAUL E. An Investigation of Bridge Deck Overhang Falsework Systems Installed onto Bulb Tee Girders. (Under the direction of Dr. Emmett Sumner.)

    E-Print Network [OSTI]

    Bulb Tee Girders. (Under the direction of Dr. Emmett Sumner.) Bulb Tee girders provide a practical moments of inertia to withstand the massive moments created in the spans. A bulb tee girder possesses the thin top flange of an exterior bulb tee girder in the bridge deck overhang falsework system to fail

  7. Exam Stochastic Processes 2WB08 January 29, 2007 A light bulb burns for an amount of time having distribution F(), with Laplace trans-

    E-Print Network [OSTI]

    Giardinà, Cristian

    Exam Stochastic Processes 2WB08 ­ January 29, 2007 Problem 1: A light bulb burns for an amount moment µ2. When the light bulb burns out, it is immediately replaced by another light bulb which has the same life time distribution F(·), etc. Let m(t) be the mean number of replacements of light bulbs upto

  8. Chem 115Lithium-Halogen ExchangeMyers RLi + R'X RX + R'Li

    E-Print Network [OSTI]

    Chem 115Lithium-Halogen ExchangeMyers RLi + R'X RX + R'Li Lithium-halogen exchange reactions are essentially inert. 2 t-BuLi t-BuI + RLi t-BuLi isobutene + isobutane + LiI Lithium-halogen exchange reactions, and lithium iodide. H OEtBr H H OEtLi H1.1 eq n-BuLi Et2O, !80 °C Lau, K. S.; Schlosser, M. J. Org. Chem. 1978

  9. 600 New Lights Bulbs to Improve Energy Efficiency at DOE | Department...

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

    our Washington, D.C., Forrestal North Building canopy with state of the art Light Emitting Diode (LED) fixtures. Every new bulb now uses just 23 watts instead of 205 watts....

  10. A critical period for activity-dependent synaptic development during olfactory bulb adult neurogenesis

    E-Print Network [OSTI]

    Kelsch, Wolfgang

    New neurons integrate in large numbers into the mature olfactory bulb circuit throughout life. The factors controlling the synaptic development of adult-born neurons and their connectivity remain essentially unknown. We ...

  11. Westinghouse Pays $50,000 Civil Penalty to Resolve Light Bulb...

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

    here. Addthis Related Articles DOE Requires Westinghouse to Cease Sales of Two Light Bulb Models and Allows Sale of Another Air-Con Agrees to Pay Civil Penalty to Resolve...

  12. 2.44a0005 Physiology of the Main Olfactory Bulb Matthew Ennis1

    E-Print Network [OSTI]

    Hayar, Abdallah

    -inhibition 27 2.44.6.4.2 Lateral inhibition 27 2.44.6.4.3 Role of Ca2þ influx through NMDA receptors and voltage.44.8 Neurophysiology of Primary Olfactory Cortical Inputs to Main Olfactory Bulb 29 2.44.9 Oscillations and Synchrony in Main Olfactory Bulb 29 2.44.9.1 Oscillations 29 2.44.9.1.1 Theta rhythm 30 2.44.9.1.2 Gamma rhythm 30 2

  13. Interrelationships between air velocity and natural wet-bulb thermometer response

    E-Print Network [OSTI]

    Jones, Nathan Glenn

    1983-01-01T23:59:59.000Z

    INTERRELATIONSHIPS BETWEEN AIR VFLOCITY ANO NATURAL WET-BULB THERMOMETER RESPONSE A Thesis by NATHAN GLENN JONES Submitted to the Graduate Colleqe of Texas ASM University i n partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE AUGUST 1983 Major Subject: Industrial Hygiene INTERRELATIONSHIPS BETWEEN AIR VELOCITY AND NATURAL WET-BULB THERMOMETER RESPONSE A Thesis by NATHAN GLENN JONES Approved as to style an content by: airman o ommittee er Member ~~' A~ Member...

  14. Spatial assessment of net mercury emissions from the use of fluorescent bulbs

    SciTech Connect (OSTI)

    Matthew J. Eckelman; Paul T. Anastas; Julie B. Zimmerman [Yale University, New Haven, CT (United States). Department of Chemical Engineering

    2008-11-15T23:59:59.000Z

    While fluorescent lighting is an important technology for reducing electrical energy demand, mercury used in the bulbs is an ongoing concern. Using state and country level data, net emissions of mercury from the marginal use of fluorescent lightbulbs are examined for a base year of 2004 for each of the 50 United States and 130 countries. Combustion of coal for electric power generation is generally the largest source of atmospheric mercury pollution; reduction in electricity demand from the substitution of incandescent bulbs with fluorescents leads to reduced mercury emissions during the use of the bulb. This analysis considers the local mix of power sources, coal quality, thermal conversion efficiencies, distribution losses, and any mercury control technologies that might be in place. Emissions of mercury from production and end-of-life treatment of the bulbs are also considered, providing a life-cycle perspective. Net reductions in mercury over the entire life cycle range from -1.2 to 97 mg per bulb depending on the country. The consequences for atmospheric mercury emissions of several policy scenarios are also discussed. 46 refs., 4 figs., 3 tabs.

  15. Unbound particles in dark matter halos

    SciTech Connect (OSTI)

    Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, Physics Department, Stanford University and SLAC National Accelerator Laboratory 2575 Sand Hill Road, Menlo Park, CA (United States); Loeb, Abraham, E-mail: behroozi@stanford.edu, E-mail: aloeb@cfa.harvard.edu, E-mail: rwechsler@stanford.edu [Department of Astronomy, Harvard University 60 Garden St, Cambridge, MA (United States)

    2013-06-01T23:59:59.000Z

    We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.

  16. System and method for monitoring wet bulb temperature in a flue gas stream

    SciTech Connect (OSTI)

    Glover, R.L.; Bland, V.V.

    1990-01-02T23:59:59.000Z

    This patent describes in a system for monitoring wet bulb temperature in a flue gas stream means for extracting a sample of the gas from the flue, means for heating the sample to maintain the sample at substantially the same temperature as the gas in the flue, a sensor for measuring the wet bulb temperature of the sample, a reservoir of liquid, a liquid absorbent wick surrounding the sensor and extending into the liquid in the reservoir, and means for maintaining the liquid in the reservoir at a substantially constant level.

  17. Tired of changing light bulbs AND want to save money? Still using 100 year-old technology?

    E-Print Network [OSTI]

    Glashausser, Charles

    ?) ·Fine print: You will also reduce Global Warming pollution. Over its lifetime, a "100W" Compact will prevent global warming pollution equal to 100 to 150 gallons of gasoline AND reduce poisons like mercury bulb but lasts THIRTEEN times longer! The Compact bulb will save you $90 just in electricity cost over

  18. Bulbs for Winter Bloom The trees have all dropped their leaves and our gardens are covered by a blanket of snow. It is too

    E-Print Network [OSTI]

    New Hampshire, University of

    Bulbs for Winter Bloom The trees have all dropped their leaves and our gardens are covered into an inside garden. Paperwhite Narcissus and Amaryllis bulbs both produce beautiful flowers. They are easy bulbs to grow inside a house. Paperwhites come in two colors, white and yellow. They are extremely easy

  19. Instructions for Corning Model 220 pH Meter The electrode tip is a fragile glass bulb. Be careful or you will break it with a

    E-Print Network [OSTI]

    Cross, George

    Instructions for Corning Model 220 pH Meter The electrode tip is a fragile glass bulb. Be careful a polymer body electrode can create sufficient internal pressure to "explode" the glass bulb. When of cotton in the plastic electrode cover sleeve, add pH 7 buffer, and insert the electrode bulb

  20. UNH Cooperative Extension Info Line Question of the Week Q. What should I do with the Amaryllis bulb I just received?

    E-Print Network [OSTI]

    New Hampshire, University of

    bulb I just received? A. Few flowers give greater satisfaction than the spectacular amaryllis. Amaryllis are available from September to March as dormant bulbs ready for planting. They can be purchased as bulbs or as pre packaged units complete with pots and potting medium. Shortly after planting one or two

  1. Plant Disease Note 2004 | Iris Yellow Spot Virus in Onion Bulb and Seed Crops in Washington Overview Current Issue Past Issues Search PD Search APS Journals

    E-Print Network [OSTI]

    Pappu, Hanu R.

    Plant Disease Note 2004 | Iris Yellow Spot Virus in Onion Bulb and Seed Crops in Washington Yellow Spot Virus in Onion Bulb and Seed Crops in Washington. L. J. du Toit, Washington State University of the NP gene. In August 2003, symptoms of IYSV infection were observed in two onion bulb crops, each

  2. The Hazards of Use and Disposal of Compact Fluorescent Bulbs Compact fluorescent lights (aka. CFLs) work by exciting a phosphorous coating within the tube to emit

    E-Print Network [OSTI]

    Maroncelli, Mark

    The Hazards of Use and Disposal of Compact Fluorescent Bulbs Compact fluorescent lights (aka. CFLs the bulb to be an efficient light source. By comparison, older home thermometers contain 500 milligrams decade. HOW SHOULD I DISPOSE OF CFL'S? The presence of mercury requires that all CFL bulbs are properly

  3. Catalytic, Asymmetric r-Halogenation Harald Wack, Andrew E. Taggi, Ahmed M. Hafez,

    E-Print Network [OSTI]

    Lectka, Thomas

    reported "relay" deprotonation strategy,5 in which protons are shuttled from the chiral amine catalyst Phenylacetyl chloride 1a was used as a test substrate to screen the various halogenating agents using 10 mol

  4. Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion

    E-Print Network [OSTI]

    Sims, Gerald K.

    Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion Martin M. Williams II, Corey V. Ransom, and W. Mack Thompson* Volunteer potato is highly competitive with onion and few control tactics are effective for removing this weed from an onion crop. Both volunteer potato density

  5. On mini-halo encounters with stars

    E-Print Network [OSTI]

    Anne M. Green; Simon P. Goodwin

    2006-12-11T23:59:59.000Z

    We study, analytically and numerically, the energy input into dark matter mini-haloes by interactions with stars. We find that the fractional energy input in simulations of Plummer spheres agrees well with the impulse approximation for small and large impact parameters, with a rapid transition between these two regimes. Using the impulse approximation the fractional energy input at large impact parameters is fairly independent of the mass and density profile of the mini-halo, however low-mass mini-haloes experience a greater fractional energy input in close encounters. We formulate a fitting function which encodes these results and use it to estimate the disruption timescales of mini-haloes, taking into account the stellar velocity dispersion and mass distribution. For mini-haloes with mass M< {\\cal O}(10^{-7} M_{\\odot} on typical orbits which pass through the disc, we find that the estimated disruption timescales are independent of mini-halo mass, and are of order the age of the Milky Way. For more massive mini-haloes the estimated disruption timescales increase rapidly with increasing mass.

  6. Metal Enrichment in the Early Galactic Halo

    E-Print Network [OSTI]

    C. Ikuta; N. Arimoto

    1999-06-14T23:59:59.000Z

    An early history of metal enrichment in the Galactic halo is studied. We investigate chemical inhomogeneity by using a stochastic chemical evolution model. The model confronts with metallicity distribution function of long-lived halo stars which is found to be a clue to obtain the best model prescriptions. We find that the star formation in the halo virtually terminated by around 1 Gyr and that the halo has never been chemically homogeneous in its star formation history. This conclusion does not depend whether mass loss from the halo is taken into account or not. Observed ratios of alpha-elements with respect to iron do not show scatters on a [alpha/Fe]-[Fe/H] plane, but this does not imply that interstellar matter in the halo was homogeneous because a chemical evolution path on this diagram is degenerate in the star formation rate. On the other hand, apparent spread of [Sr/Fe] ratio among metal-poor halo stars does not reflect an inhomogeneous metal enrichment, instead it is due to a sharp increase in a production rate of strontium that is probably synthesised in slightly less massive stars than progenitor of iron-producing SNII.

  7. Simulating the Gaseous Halos of Galaxies

    E-Print Network [OSTI]

    Tobias Kaufmann; James S. Bullock; Ari Maller; Taotao Fang

    2008-01-28T23:59:59.000Z

    Observations of local X-ray absorbers, high-velocity clouds, and distant quasar absorption line systems suggest that a significant fraction of baryons may reside in multi-phase, low-density, extended, ~100 kpc, gaseous halos around normal galaxies. We present a pair of high-resolution SPH (smoothed particle hydrodynamics) simulations that explore the nature of cool gas infall into galaxies, and the physical conditions necessary to support the type of gaseous halos that seem to be required by observations. The two simulations are identical other than their initial gas density distributions: one is initialized with a standard hot gas halo that traces the cuspy profile of the dark matter, and the other is initialized with a cored hot halo with a high central entropy, as might be expected in models with early pre-heating feedback. Galaxy formation proceeds in dramatically different fashions in these two cases. While the standard cuspy halo cools rapidly, primarily from the central region, the cored halo is quasi-stable for ~4 Gyr and eventually cools via the fragmentation and infall of clouds from ~100 kpc distances. After 10 Gyr of cooling, the standard halo's X-ray luminosity is ~100 times current limits and the resultant disk galaxy is twice as massive as the Milky Way. In contrast, the cored halo has an X-ray luminosity that is in line with observations, an extended cloud population reminiscent of the high-velocity cloud population of the Milky Way, and a disk galaxy with half the mass and ~50% more specific angular momentum than the disk formed in the low-entropy simulation. These results suggest that the distribution and character of halo gas provides an important testing ground for galaxy formation models and may be used to constrain the physics of galaxy formation.

  8. High resolution studies of massive primordial haloes

    E-Print Network [OSTI]

    Latif, M A; Schmidt, W; Niemeyer, J

    2012-01-01T23:59:59.000Z

    Atomic cooling haloes with T_vir > 10^4 K are the most plausible sites for the formation of the first galaxies. In this article, we aim to study the implications of gravity driven turbulence in protogalactic haloes. By varying the resolution per Jeans length, we explore whether the turbulent cascade is resolved well enough to obtain converged results. We have performed high resolution cosmological simulations using the adaptive mesh refinement code Enzo including a subgrid-scale turbulence model to study the role of unresolved turbulence. We compared the results of three different Jeans resolutions from 16 to 64 cells. While radially averaged profiles roughly agree at different resolutions, differences in the morphology reveal that even the highest resolution employed provides no convergence. Moreover, taking into account unresolved turbulence significantly influences the morphology of a halo. We have quantified the properties of the high-density clumps in the halo. These clumps are gravitationally unbound wi...

  9. Halo occupation numbers and galaxy bias

    E-Print Network [OSTI]

    J. A. Peacock; R. E. Smith

    2000-06-30T23:59:59.000Z

    We propose a heuristic model that displays the main features of realistic theories for galaxy bias. We show that the low-order clustering statistics of the dark-matter distribution depend almost entirely on the locations and density profiles of dark-matter haloes. A hypothetical galaxy catalogue depends on (i) the efficiency of galaxy formation, as manifested by the halo occupation number -- the number of galaxies brighter than some sample limit contained in a halo of a given mass; (ii) the location of these galaxies within their halo. The first factor is constrained by the empirical luminosity function of groups. For the second factor, we assume that one galaxy marks the halo centre, with any remaining galaxies acting as satellites that trace the halo mass. These simple assumptions amount to a recipe for non-local bias, in which the probability of finding a galaxy is not a simple function of its local mass density. We have applied this prescription to some CDM models of current interest, and find that the predictions are close to the observed galaxy correlations for a flat $\\Omega=0.3$ model ($\\Lambda$CDM), but not for an $\\Omega=1$ model with the same power spectrum ($\\tau$CDM). This is an inevitable consequence of cluster normalization for the power spectra: cluster-scale haloes of given mass have smaller core radii for high $\\Omega$, and hence display enhanced small-scale clustering. Finally, the pairwise velocity dispersion of galaxies in the $\\Lambda$CDM model is lower than that of the mass, allowing cluster-normalized models to yield a realistic Mach number for the peculiar velocity field. This is largely due to the strong variation of galaxy-formation efficiency with halo mass that is required in this model.

  10. Halo Formation in Warm Dark Matter Models

    E-Print Network [OSTI]

    Paul Bode; Jeremiah P. Ostriker; Neil Turok

    2001-05-29T23:59:59.000Z

    Discrepancies have emerged between the predictions of standard cold dark matter (CDM) theory and observations of clustering on sub-galactic scales. Warm dark matter (WDM) is a simple modification of CDM in which the dark matter particles have initial velocities due either to their having decoupled as thermal relics, or having been formed via non-equilibrium decay. We investigate the nonlinear gravitational clustering of WDM with a high resolution N-body code, and identify a number of distinctive observational signatures. Relative to CDM, halo concentrations and core densities are lowered, core radii are increased, and large halos emerge with far fewer low mass satellites. The number of small halos is suppressed, and those present are formed by `top down' fragmentation of caustics, as part of a `cosmic web' connecting massive halos. Few small halos form outside this web. If we identify small halos with dwarf galaxies, their number, spatial distribution, and formation epoch appear in better agreement with the observations for WDM than they are for CDM.

  11. Some cultural practices affecting bulb rot, plant and floral development, and seed yield of the White Grano onion

    E-Print Network [OSTI]

    Enzie, Joseph Vincent

    1955-01-01T23:59:59.000Z

    L IBRARY A&IW COLLEGE OF TEXAS SOME CULTURAL PRACTICES AFFECTING BULB ROT, PLANT AND FLORAL DEVELOPMENT, AND SEED YIELD OF THE WHITE GRANO ONION A Dissertation By JOSEPH V. ENZIE Submitted to the Graduate School of the Agricultural... and Mechanical College of Texas in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 1955 Major Subject: Horticulture SOME CULTURAL PRACTICES AFFECTING BULB ROT, PLANT AND FLORAL DEVELOPMENT, AND SEED YIELD OF THE WHITE GRANO...

  12. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOE Patents [OSTI]

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1983-09-20T23:59:59.000Z

    A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

  13. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOE Patents [OSTI]

    Googin, John M. (Oak Ridge, TN); Napier, John M. (Oak Ridge, TN); Travaglini, Michael A. (Oliver Springs, TN)

    1983-01-01T23:59:59.000Z

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced.

  14. Analysis of Halogen-Mercury Reactions in Flue Gas

    SciTech Connect (OSTI)

    Paula Buitrago; Geoffrey Silcox; Constance Senior; Brydger Van Otten

    2010-01-01T23:59:59.000Z

    Oxidized mercury species may be formed in combustion systems through gas-phase reactions between elemental mercury and halogens, such as chorine or bromine. This study examines how bromine species affect mercury oxidation in the gas phase and examines the effects of mixtures of bromine and chlorine on extents of oxidation. Experiments were conducted in a bench-scale, laminar flow, methane-fired (300 W), quartz-lined reactor in which gas composition (HCl, HBr, NO{sub x}, SO{sub 2}) and temperature profile were varied. In the experiments, the post-combustion gases were quenched from flame temperatures to about 350 C, and then speciated mercury was measured using a wet conditioning system and continuous emissions monitor (CEM). Supporting kinetic calculations were performed and compared with measured levels of oxidation. A significant portion of this report is devoted to sample conditioning as part of the mercury analysis system. In combustion systems with significant amounts of Br{sub 2} in the flue gas, the impinger solutions used to speciate mercury may be biased and care must be taken in interpreting mercury oxidation results. The stannous chloride solution used in the CEM conditioning system to convert all mercury to total mercury did not provide complete conversion of oxidized mercury to elemental, when bromine was added to the combustion system, resulting in a low bias for the total mercury measurement. The use of a hydroxylamine hydrochloride and sodium hydroxide solution instead of stannous chloride showed a significant improvement in the measurement of total mercury. Bromine was shown to be much more effective in the post-flame, homogeneous oxidation of mercury than chlorine, on an equivalent molar basis. Addition of NO to the flame (up to 400 ppmv) had no impact on mercury oxidation by chlorine or bromine. Addition of SO{sub 2} had no effect on mercury oxidation by chlorine at SO{sub 2} concentrations below about 400 ppmv; some increase in mercury oxidation was observed at SO{sub 2} concentrations of 400 ppmv and higher. In contrast, SO{sub 2} concentrations as low as 50 ppmv significantly reduced mercury oxidation by bromine, this reduction could be due to both gas and liquid phase interactions between SO{sub 2} and oxidized mercury species. The simultaneous presence of chlorine and bromine in the flue gas resulted in a slight increase in mercury oxidation above that obtained with bromine alone, the extent of the observed increase is proportional to the chlorine concentration. The results of this study can be used to understand the relative importance of gas-phase mercury oxidation by bromine and chlorine in combustion systems. Two temperature profiles were tested: a low quench (210 K/s) and a high quench (440 K/s). For chlorine the effects of quench rate were slight and hard to characterize with confidence. Oxidation with bromine proved sensitive to quench rate with significantly more oxidation at the lower rate. The data generated in this program are the first homogeneous laboratory-scale data on bromine-induced oxidation of mercury in a combustion system. Five Hg-Cl and three Hg-Br mechanisms, some published and others under development, were evaluated and compared to the new data. The Hg-halogen mechanisms were combined with submechanisms from Reaction Engineering International for NO{sub x}, SO{sub x}, and hydrocarbons. The homogeneous kinetics under-predicted the levels of mercury oxidation observed in full-scale systems. This shortcoming can be corrected by including heterogeneous kinetics in the model calculations.

  15. The Mass-Function of Low Mass Halo Stars: Limits on Baryonic Halo Dark Matter

    E-Print Network [OSTI]

    David S. Graff; Katherine Freese

    1996-06-18T23:59:59.000Z

    We derive mass functions (MF) for halo red dwarfs (the faintest hydrogen burning stars) and then extrapolate to place limits on the total mass of halo brown dwarfs (stars not quite massive enough to burn hydrogen). The mass functions are obtained from the luminosity function of a sample of 114 local halo stars in the USNO parallax survey (Dahn \\etal 1995). We use stellar models of Alexander \\etal (1996) and make varying assumptions about metallicity and about possible unresolved binaries in the sample. We find that the MF for halo red dwarfs cannot rise more quickly than $1/m^2$ as one approaches the hydrogen burning limit. Using recent results from star formation theory, we extrapolate the MF into the brown-dwarf regime. We see that likely extrapolations imply that the total mass of brown dwarfs in the halo is less than $\\sim 3\\%$ of the local mass density of the halo ($\\sim 0.3\\%$ for the more realistic models we consider). Our limits apply to brown dwarfs in the halo that come from the same stellar population as the red dwarfs.

  16. Neutrino flavor transformation in core-collapse supernovae

    E-Print Network [OSTI]

    Cherry, John F.; Cherry, John F.

    2012-01-01T23:59:59.000Z

    the corresponding Neutrino Bulb (1 %) safety criteria fromof the neutrino- bulb halo neutrino Hamiltonian, | H |+|H |, to the contribution from bulb the neutrinosphere | H

  17. Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater

    E-Print Network [OSTI]

    compounds; Groundwater management; Drinking water. Introduction Approximately one-half of the U and Hitt 2006 , or more complex process-based analyses utilizing groundwater models Eberts et al. 2005Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater: Use in Vulnerability

  18. Direct Detection of Galactic Halo Dark Matter

    E-Print Network [OSTI]

    Oppenheimer, Ben R.

    inferred because the grav- itational field due to the known distribution of luminous matter, primarily, photographic plates in the R59F and BJ pass- bands from the SuperCOSMOS Sky Survey (12­14). R59F and BJ roughly% of the sky. Because of image blending problems and large halos of scattered light around bright stars

  19. Baryonic pinching of galactic dark matter halos

    SciTech Connect (OSTI)

    Gustafsson, Michael; Fairbairn, Malcolm; Sommer-Larsen, Jesper [Cosmology, Particle Astrophysics and String Theory, Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91, Stockholm (Sweden); Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

    2006-12-15T23:59:59.000Z

    High resolution cosmological N-body simulations of four galaxy-scale dark matter halos are compared to corresponding N-body/hydrodynamical simulations containing dark matter, stars and gas. The simulations without baryons share features with others described in the literature in that the dark matter density slope continuously decreases towards the center, with a density {rho}{sub DM}{proportional_to}r{sup -1.3{+-}}{sup 0.2}, at about 1% of the virial radius for our Milky Way sized galaxies. The central cusps in the simulations which also contain baryons steepen significantly, to {rho}{sub DM}{proportional_to}r{sup -1.9{+-}}{sup 0.2}, with an indication of the inner logarithmic slope converging. Models of adiabatic contraction of dark matter halos due to the central buildup of stellar/gaseous galaxies are examined. The simplest and most commonly used model, by Blumenthal et al., is shown to overestimate the central dark matter density considerably. A modified model proposed by Gnedin et al. is tested and it is shown that, while it is a considerable improvement, it is not perfect. Moreover, it is found that the contraction parameters in their model not only depend on the orbital structure of the dark-matter-only halos but also on the stellar feedback prescription which is most relevant for the baryonic distribution. Implications for dark matter annihilation at the galactic center are discussed and it is found that, although our simulations show a considerable reduced dark matter halo contraction as compared to the Blumenthal et al. model, the fluxes from dark matter annihilation are still expected to be enhanced by at least a factor of a hundred, as compared to dark-matter-only halos. Finally, it is shown that, while dark-matter-only halos are typically prolate, the dark matter halos containing baryons are mildly oblate with minor-to-major axis ratios of c/a=0.73{+-}0.11, with their flattening aligned with the central baryonic disks.

  20. Dynamics of the Disruption Halo Current Toroidal Asymmetry in NSTX

    SciTech Connect (OSTI)

    S.P. Gerhardt

    2012-09-27T23:59:59.000Z

    This paper describes the dynamics of disruption halo current non-axisymmetries in the lower divertor of the National Spherical Torus Experiment [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. While. The halo currents typically have a strongly asymmetric structure where they enter the divertor floor, and this asymmetry has been observed to complete up to 7 toroidal revolutions over the duration of the halo current pulse. However, the rotation speed and toroidal extend of the asymmetry can vary significantly during the pulse. The rotation speed, halo current pulse duration, and total number of revolutions tend to be smaller in cases with large halo currents. The halo current pattern is observed to become toroidally symmetric at the end of the halo current pulse. It is proposed that this symmeterization is due to the loss of most or all of the closed field line geometry in the final phase of the vertical displacement event.

  1. Halogen emissions from a small volcanic eruption: Modeling the peak concentrations, dispersion, and volcanically induced ozone loss in the

    E-Print Network [OSTI]

    Rose, William I.

    , with lesser quantities of H2S, H2 and CO. Volcanic emissions also often include halogen-bearing species, and the greater water vapor content in the lower troposphere at tropical latitudes, which enhance removal

  2. Oxidative halogenation of cisplatin and carboplatin: synthesis, spectroscopy, and crystal and molecular structures of Pt(IV) prodrugs

    E-Print Network [OSTI]

    Alexander, Sarah M.

    A series of Pt(IV) prodrugs has been obtained by oxidative halogenation of either cisplatin or carboplatin. Iodobenzene dichloride is a general reagent that cleanly provides prodrugs bearing axial chlorides without the ...

  3. ONION (Allium cepa, 47 cultivars) B.K. Schroeder, Washington State University (WSU), Pullman, Enterobacter bulb decay; Enterobacter cloacae WA 99164; T.D. Waters, WSU Franklin Co. Extension, Pasco WA

    E-Print Network [OSTI]

    Schroeder, Brenda K.

    , Enterobacter bulb decay; Enterobacter cloacae WA 99164; T.D. Waters, WSU Franklin Co. Extension, Pasco WA 99301 in storage in Washington State, 2008-2009. An onion bulb storage trial was completed to survey 47 storage to Enterobacter cloacae, causal agent of Enterobacter bulb decay. Seeds of each cultivar were planted near Pasco

  4. ONION (Allium cepa, 55 cultivars) B.K. Schroeder, Washington State University (WSU), Pullman, Enterobacter bulb decay; Enterobacter cloacae WA 99164; T. Waters, WSU Franklin Co. Extension, Pasco WA

    E-Print Network [OSTI]

    Schroeder, Brenda K.

    , Enterobacter bulb decay; Enterobacter cloacae WA 99164; T. Waters, WSU Franklin Co. Extension, Pasco WA 99301 for resistance to Enterobacter cloacae in storage, 2007-2008. An onion bulb storage trial was completed to survey for resistance to Enterobacter cloacae, causal agent of Enterobacter bulb decay. Seeds of each cultivar were

  5. Evidence for universal structure in galactic halos

    E-Print Network [OSTI]

    William H. Kinney; Pierre Sikivie

    1999-06-02T23:59:59.000Z

    The late infall of dark matter onto a galaxy produces structure (such as caustics) in the distribution of dark matter in the halo. We argue that such structure is likely to occur generically on length scales proportional to $l \\sim t_0 v_{rot}$, where $t_0$ is the age of the universe and $v_{rot}$ is the rotation velocity of the galaxy. A set of 32 extended galactic rotation curves is analyzed. For each curve, the radial coordinate is rescaled according to $r\\to \\tilde r \\equiv r (v_0 / v_{rot})$, where we choose $v_0 = 220 km/s$. A linear fit to each rescaled rotation curve is subtracted, and the residuals are binned and averaged. The sample shows significant features near $\\tilde r = 40 kpc$ and $\\tilde r = 20 kpc$. This is consistent with the predictions of the self-similar caustic ring model of galactic halos.

  6. THE SPHERICALIZATION OF DARK MATTER HALOS BY GALAXY DISKS

    SciTech Connect (OSTI)

    Kazantzidis, Stelios [Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Abadi, Mario G. [Instituto de Astronomia Teorica y Experimental (IATE), Observatorio Astronomico de Cordoba and CONICET, Laprida 854 X5000BGR Cordoba (Argentina); Navarro, Julio F., E-mail: stelios@mps.ohio-state.ed, E-mail: mario@oac.uncor.ed, E-mail: jfn@uvic.c [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada)

    2010-09-01T23:59:59.000Z

    Cosmological simulations indicate that cold dark matter (CDM) halos should be triaxial. Validating this theoretical prediction is, however, less than straightforward because the assembly of galaxies is expected to modify halo shapes and to render them more axisymmetric. We use a suite of N-body simulations to quantitatively investigate the effect of the growth of a central disk galaxy on the shape of triaxial dark matter halos. In most circumstances, the halo responds to the presence of the disk by becoming more spherical. The net effect depends weakly on the timescale of the disk assembly but noticeably on the orientation of the disk relative to the halo principal axes, and it is maximal when the disk symmetry axis is aligned with the major axis of the halo. The effect depends most sensitively on the overall gravitational importance of the disk. Our results indicate that exponential disks whose contribution peaks at less than {approx}50% of their circular velocity are unable to noticeably modify the shape of the gravitational potential of their surrounding halos. Many dwarf and low surface brightness galaxies are expected to be in this regime, and therefore their detailed kinematics could be used to probe halo triaxiality, one of the basic predictions of the CDM paradigm. We argue that the complex disk kinematics of the dwarf galaxy NGC 2976 might be the reflection of a triaxial halo. Such signatures of halo triaxiality should be common in galaxies where the luminous component is subdominant.

  7. The dependence on environment of Cold Dark Matter Halo properties

    E-Print Network [OSTI]

    V. Avila-Reese; P. Colin; S. Gottloeber; C. Firmani; C. Maulbetsch

    2005-08-01T23:59:59.000Z

    High-resolution LCDM cosmological N-body simulations are used to study the properties of galaxy-size dark halos in different environments (cluster, void, and "field"). Halos in clusters and their surroundings have a median spin parameter ~1.3 times lower, and tend to be more spherical and to have less aligned internal angular momentum than halos in voids and the field. For halos in clusters the concentration parameters decrease on average with mass with a slope of ~0.1; for halos in voids these concentrations do not change with mass. For masses environments. At z=1, the differences in the halo properties with environment almost dissapear, suggesting this that the differences were stablished mainly after z~1. The halos in clusters undergo more dramatic changes than those in the field or the voids. The differences with environment are owing to (i) the dependence of halo formation time on environment, and (ii) local effects as tidal stripping and the tumultuos histories that halos suffer in high-density regions. We calculate seminumerical models of disk galaxy evolution in halos with the properties found for the different environments. For a given disk mass, the galaxy disks have higher surface density, larger Vd,max and secular bulge-to-disk ratio, lower gas fraction, and are redder as one goes from cluster to void environments, in rough agreement with observations. (abridged)

  8. Merger Rates of Dark-Matter Haloes

    E-Print Network [OSTI]

    Eyal Neistein; Avishai Dekel

    2008-05-22T23:59:59.000Z

    We derive analytic merger rates for dark-matter haloes within the framework of the Extended Press-Schechter (EPS) formalism. These rates become self-consistent within EPS once we realize that the typical merger in the limit of a small time-step involves more than two progenitors, contrary to the assumption of binary mergers adopted in earlier studies. We present a general method for computing merger rates that span the range of solutions permitted by the EPS conditional mass function, and focus on a specific solution that attempts to match the merger rates in N-body simulations. The corrected EPS merger rates are more accurate than the earlier estimates of Lacey & Cole, by ~20% for major mergers and by up to a factor of ~3 for minor mergers of mass ratio 1:10^4. Based on the revised merger rates, we provide a new algorithm for constructing Monte-Carlo EPS merger trees, that could be useful in Semi-Analytic Modeling. We provide analytic expressions and plot numerical results for several quantities that are very useful in studies of galaxy formation. This includes (a) the rate of mergers of a given mass ratio per given final halo, (b) the fraction of mass added by mergers to a halo, and (c) the rate of mergers per given main progenitor. The creation and destruction rates of haloes serve for a self-consistency check. Our method for computing merger rates can be applied to conditional mass functions beyond EPS, such as those obtained by the ellipsoidal collapse model or extracted from $N$-body simulations.

  9. Mercury Lamps Recycling Fluorescent light-tubes, compact fluorescent bulbs, mercury and sodium vapor lamps, ultraviolet and

    E-Print Network [OSTI]

    Baker, Chris I.

    Mercury Lamps Recycling Fluorescent light-tubes, compact fluorescent bulbs, mercury and sodium labeled for shipment to a recycling plant for mercury, glass and aluminum recovery. The beneficial re can be recycled infinitely without losing its purity or strength. While the primary end product

  10. Comparing halo bias from abundance and clustering

    E-Print Network [OSTI]

    Hoffmann, Kai; Gaztanaga, Enrique

    2015-01-01T23:59:59.000Z

    We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

  11. r-Process Enhanced Halo Stars

    E-Print Network [OSTI]

    J. J. Cowan; C. Sneden; J. E. Lawler; E. A. Den Hartog

    2006-10-13T23:59:59.000Z

    Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy -- the progenitors of the halo stars -- responsible for neutron-capture synthesis of the heavy elements. The large star-to-star scatter observed in the abundances of neutron-capture element/iron ratios at low metallicities -- which diminishes with increasing metallicity or [Fe/H] -- suggests the formation of these heavy elements (presumably from certain types of supernovae) was rare in the early Galaxy. The stellar abundances also indicate a change from the r-process to the slow neutron capture (i.e., s-) process at higher metallicities in the Galaxy and provide insight into Galactic chemical evolution. Finally, the detection of thorium and uranium in halo and globular cluster stars offers an independent age-dating technique that can put lower limits on the age of the Galaxy, and hence the Universe.

  12. Method of increments for the halogen molecular crystals: Cl, Br, and I

    SciTech Connect (OSTI)

    Steenbergen, Krista G. [Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany); MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Gaston, Nicola [MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Müller, Carsten; Paulus, Beate [Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany)

    2014-09-28T23:59:59.000Z

    Method of increments (MI) calculations reveal the n-body correlation contributions to binding in solid chlorine, bromine, and iodine. Secondary binding contributions as well as d-correlation energies are estimated and compared between each solid halogen. We illustrate that binding is entirely determined by two-body correlation effects, which account for >80% of the total correlation energy. One-body, three-body, and exchange contributions are repulsive. Using density-fitting (DF) local coupled-cluster singles, doubles, and perturbative triples for incremental calculations, we obtain excellent agreement with the experimental cohesive energies. MI results from DF local second-order Møller-Plesset perturbation (LMP2) yield considerably over-bound cohesive energies. Comparative calculations with density functional theory and periodic LMP2 method are also shown to be less accurate for the solid halogens.

  13. Changes in neurotransmitter levels and proinflammatory cytokine mRNA expressions in the mice olfactory bulb following nanoparticle exposure

    SciTech Connect (OSTI)

    Tin-Tin-Win-Shwe [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)], E-mail: tin.tin.win.shwe@nies.go.jp; Mitsushima, Dai [Department of Physiology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawaku, Yokohama 236-0004 (Japan); Yamamoto, Shoji; Fukushima, Atsushi [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Funabashi, Toshiya [Department of Physiology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawaku, Yokohama 236-0004 (Japan); Kobayashi, Takahiro; Fujimaki, Hidekazu [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2008-01-15T23:59:59.000Z

    Recently, there have been increasing reports that nano-sized component of particulate matter can reach the brain and may be associated with neurodegenerative diseases. Previously, our laboratory has studied the effect of intranasal instillation of nano-sized carbon black (CB) (14 nm and 95 nm) on brain cytokine and chemokine mRNA expressions and found that 14-nm CB increased IL-1{beta}, TNF-{alpha}, CCL2 and CCL3 mRNA expressions in the olfactory bulb, not in the hippocampus of mice. To investigate the effect of a single administration of nanoparticles on neurotransmitters and proinflammatory cytokines in a mouse olfactory bulb, we performed in vivo microdialysis and real-time PCR methods. Ten-week-old male BALB/c mice were implanted with guide cannula in the right olfactory bulb and, 1 week later, were instilled vehicle or CB (14 nm, 250 {mu}g) intranasally. Six hours after the nanoparticle instillation, the mice were intraperitoneally injected with normal saline or 50 {mu}g of bacteria cell wall component lipoteichoic acid (LTA), which may potentiate CB-induced neurologic effect. Extracellular glutamate and glycine levels were significantly increased in the olfactory bulb of CB-instilled mice when compared with vehicle-instilled control mice. Moreover, we found that LTA further increased glutamate and glycine levels. However, no alteration of taurine and GABA levels was observed in the olfactory bulb of the same mice. We also detected immunological changes in the olfactory bulb 11 h after vehicle or CB instillation and found that IL-1{beta} mRNA expression was significantly increased in CB- and LTA-treated mice when compared with control group. However, TNF-{alpha} mRNA expression was increased significantly in CB- and saline-treated mice when compared with control group. These findings suggest that nanoparticle CB may modulate the extracellular amino acid neurotransmitter levels and proinflammatory cytokine IL-1 {beta} mRNA expressions synergistically with LTA in the mice olfactory bulb.

  14. Photofragmentation spectra of halogenated methanes in the VUV photon energy range

    SciTech Connect (OSTI)

    Cartoni, Antonella, E-mail: antonella.cartoni@uniroma1.it [Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, P.le Aldo Moro 5, Roma 00185 (Italy)] [Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, P.le Aldo Moro 5, Roma 00185 (Italy); Bolognesi, Paola; Fainelli, Ettore; Avaldi, Lorenzo [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015 (Italy)] [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015 (Italy)

    2014-05-14T23:59:59.000Z

    In this paper an investigation of the photofragmentation of dihalomethanes CH{sub 2}X{sub 2} (X = F, Cl, Br, I) and chlorinated methanes (CH{sub n}Cl{sub 4?n} with n = 0–3) with VUV helium, neon, and argon discharge lamps is reported and the role played by the different halogen atoms is discussed. Halogenated methanes are a class of molecules used in several fields of chemistry and the study of their physical and chemical proprieties is of fundamental interest. In particular their photodissociation and photoionization are of great importance since the decomposition of these compounds in the atmosphere strongly affects the environment. The results of the present work show that the halogen-loss is the predominant fragmentation channel for these molecules in the VUV photon energy range and confirm their role as reservoir of chlorine, bromine, and iodine atoms in the atmosphere. Moreover, the results highlight the peculiar feature of CH{sub 2}F{sub 2} as a source of both fluorine and hydrogen atoms and the characteristic formation of I{sub 2}{sup +} and CH{sub 2}{sup +} ions from the photofragmentation of the CH{sub 2}I{sub 2} molecule.

  15. LED lamp or bulb with remote phosphor and diffuser configuration with enhanced scattering properties

    DOE Patents [OSTI]

    Tong, Tao; Le Toquin, Ronan; Keller, Bernd; Tarsa, Eric; Youmans, Mark; Lowes, Theodore; Medendorp, Jr., Nicholas W; Van De Ven, Antony; Negley, Gerald

    2014-11-11T23:59:59.000Z

    An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The properties of the diffuser, such as geometry, scattering properties of the scattering layer, surface roughness or smoothness, and spatial distribution of the scattering layer properties may be used to control various lamp properties such as color uniformity and light intensity distribution as a function of viewing angle.

  16. Distribution Function in Center of Dark Matter Halo

    E-Print Network [OSTI]

    Ding Ma; Ping He

    2008-08-01T23:59:59.000Z

    N-body simulations of dark matter halos show that the density profiles of halos behave as $\\rho(r)\\propto r^{-\\alpha(r)}$, where the density logarithmic slope $\\alpha \\simeq 1\\sim1.5$ in the center and $\\alpha \\simeq 3\\sim 4$ in the outer parts of halos. However, some observations are not in agreement with simulations in the very central region of halos. The simulations also show that velocity dispersion anisotropy parameter $\\beta\\approx 0$ in the inner part of the halo and the so called "pseudo phase-space density" $\\rho/\\sigma^3$ behaves as a power-law in radius $r$. With these results in mind, we study the distribution function and the pseudo phase-space density $\\rho/\\sigma^3$ of the center of dark matter halos and find that they are closely-related.

  17. The ecology of dark matter haloes I: The rates and types of halo interactions

    E-Print Network [OSTI]

    L'Huillier, Benjamin; Kim, Juhan

    2015-01-01T23:59:59.000Z

    Interactions such as mergers and flybys play a fundamental role in shaping galaxy morphology. Using the Horizon Run 4 cosmological N-body simulation, we studied the frequency and type of halo interactions, and their redshift evolution as a function of the environment defined by the large-scale density, pair separation, mass ratio, and target halo mass. Most interactions happen at large-scale density contrast $\\delta \\approx 20$, regardless of the redshift, corresponding to groups and relatively dense part of filaments. However, the fraction of interacting target is maximum at $\\delta \\approx 1000$. We provide a new empirical fitting form for the interaction rate as a function of the halo mass, large-scale density, and redshift. We also report the existence of two modes of interactions from the distributions of mass ratio and relative distance, implying two different physical origins of the interaction. Satellite targets lose their mass as they proceed deeper into the host halo. The relative importance of thes...

  18. COMPOSITION OF LOW-REDSHIFT HALO GAS

    SciTech Connect (OSTI)

    Cen Renyue, E-mail: cen@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)

    2013-06-20T23:59:59.000Z

    Halo gas in low-z (z < 0.5) {>=}0.1 L{sub *} galaxies in high-resolution, large-scale cosmological hydrodynamic simulations is examined with respect to three components: cold, warm, and hot with temperatures of <10{sup 5}, 10{sup 5-6}, and >10{sup 6} K, respectively. Utilizing O VI {lambda}{lambda}1032, 1038 absorption lines, the warm component is compared to observations, and agreement is found with respect to the galaxy-O VI line correlation, the ratio of the O VI line incidence rate in blue to red galaxies, and the amount of O VI mass in star-forming galaxies. A detailed account of the sources of warm halo gas (stellar feedback heating, gravitational shock heating, and accretion from the intergalactic medium), inflowing and outflowing warm halo gas metallicity disparities, and their dependencies on galaxy types and environment is also presented. With the warm component securely anchored, our simulations make the following additional predictions. First, cold gas is the primary component in inner regions with its mass comprising 50% of all gas within galactocentric radius r = (30, 150) kpc in (red, blue) galaxies. Second, at r > (30, 200) kpc in (red, blue) galaxies the hot component becomes the majority. Third, the warm component is a perpetual minority, with its contribution peaking at {approx}30% at r = 100-300 kpc in blue galaxies and never exceeding 5% in red galaxies. The significant amount of cold gas in low-z early-type galaxies, which was found in simulations and in agreement with recent observations (Thom et al.), is intriguing, as is the dominance of hot gas at large radii in blue galaxies.

  19. Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

    DOE Patents [OSTI]

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1982-03-31T23:59:59.000Z

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

  20. Visualization of nitric oxide production in the mouse main olfactory bulb by a cell-trappable copper(II) fluorescent probe

    E-Print Network [OSTI]

    McQuade, Lindsey E.

    We report the visualization of NO production using fluorescence in tissue slices of the mouse main olfactory bulb. This discovery was possible through the use of a novel, cell-trappable probe for intracellular nitric oxide ...

  1. Ecological and molecular investigation of wheat bulb fly (Delia coarctata, Fallén, Diptera: Anthomyiidae) for the advancement of population monitoring and control methodologies 

    E-Print Network [OSTI]

    Rogers, Craig David

    2012-06-22T23:59:59.000Z

    Wheat bulb fly (WBF) (Delia coarctata, Fallén, Diptera: Anthomyiidae) is a pest of commercial importance in cereal crops. Control is dependent on organophosphates some of which are restricted in the UK, while current ...

  2. Using Tidal Tails to Probe Dark Matter Halos

    E-Print Network [OSTI]

    John Dubinski; J. Christopher Mihos; Lars Hernquist

    1995-09-04T23:59:59.000Z

    We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the mass of dark halos in well-known merging pairs. We concentrate on prograde encounters between equal mass galaxies which represent the best cases for creating tidal tails, but also look at systems with different relative orientations, orbital energies and mass ratios. As the mass and extent of the dark halo increase in the model galaxies, the resulting tidal tails become shorter and less massive, even under the most favorable conditions for producing these features. Our simulations imply that the observed merging galaxies with long tidal tails ($\\sim 50-100$ kpc) such as NGC 4038/39 (the Antennae) and NGC 7252 probably have halo:disk+bulge mass ratios less than 10:1. These results conflict with the favored values of the dark halo mass of the Milky Way derived from satellite kinematics and the timing argument which give a halo:disk+bulge mass ratio of $\\sim 30:1$. However, the lower bound of the estimated dark halo mass in the Milky Way (mass ratio $\\sim 10:1$) is still consistent with the inferred tidal tail galaxy masses. Our results also conflict with the expectations of $\\Omega=1$ cosmologies such as CDM which predict much more massive and extended dark halos.

  3. Helium halo nuclei from low-momentum interactions

    E-Print Network [OSTI]

    S. Bacca; A. Schwenk; G. Hagen; T. Papenbrock

    2009-05-14T23:59:59.000Z

    We present ground-state energies of helium halo nuclei based on chiral low-momentum interactions, using the hyperspherical-harmonics method for 6He and coupled-cluster theory for 8He, with correct asymptotics for the extended halo structure.

  4. MACHO (MAssive Compact Halo Objects) Data

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

    The primary aim of the MACHO Project is to test the hypothesis that a significant fraction of the dark matter in the halo of the Milky Way is made up of objects like brown dwarfs or planets: these objects have come to be known as MACHOs, for MAssive Compact Halo Objects. The signature of these objects is the occasional amplification of the light from extragalactic stars by the gravitational lens effect. The amplification can be large, but events are extremely rare: it is necessary to monitor photometrically several million stars for a period of years in order to obtain a useful detection rate. For this purpose MACHO has a two channel system that employs eight CCDs, mounted on the 50 inch telescope at Mt. Stromlo. The high data rate (several GBytes per night) is accommodated by custom electronics and on-line data reduction. The Project has taken more than 27,000 images with this system since June 1992. Analysis of a subset of these data has yielded databases containing light curves in two colors for 8 million stars in the LMC and 10 million in the bulge of the Milky Way. A search for microlensing has turned up four candidates toward the Large Magellanic Cloud and 45 toward the Galactic Bulge. The web page for data provides links to MACHO Project data portals and various specialized interfaces for viewing or searching the data. (Specialized Interface)

  5. Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the Observed Eddington Ratio Distribution

    E-Print Network [OSTI]

    Hopkins, Philip F

    2008-01-01T23:59:59.000Z

    We use the observed distribution of Eddington ratios as a function of supermassive black hole (BH) mass to constrain models of AGN lifetimes and lightcurves. Given the observed AGN luminosity function, a model for AGN lifetimes (time above a given luminosity) translates directly to a predicted Eddington ratio distribution. Models for self-regulated BH growth, in which feedback produces a 'blowout' decay phase after some peak luminosity (shutting down accretion) make specific predictions for the lifetimes distinct from those expected if AGN are simply gas starved (without feedback) and very different from simple phenomenological 'light bulb' models. Present observations of the Eddington ratio distribution, spanning 5 decades in Eddington ratio, 3 in BH mass, and redshifts z=0-1, agree with the predictions of self-regulated models, and rule out 'light-bulb', pure exponential, and gas starvation models at high significance. We compare the Eddington ratio distributions at fixed BH mass and fixed luminosity (both ...

  6. The alignment of dark matter halos with the cosmic web

    E-Print Network [OSTI]

    Santiago G. Patiri; Antonio J. Cuesta; Francisco Prada; Juan Betancort-Rijo; Anatoly Klypin

    2006-10-23T23:59:59.000Z

    We investigate the orientation of the axes and angular momentum of dark matter halos with respect to their neighboring voids using high resolution N-body cosmological simulations. We find that the minor axis of halos tends to be aligned along the line joining the halo with the center of the void, and that the major axis is perpendicular to this line. However, we find that the angular momentum of halos does not have any particular orientation. These results may provide information about the mechanisms whereby the large-scale structure of the Universe affects galaxy formation and cast light upon the issue of the orientation of galaxy disks with respect to their host halos.

  7. Predictive factors for erectile dysfunction in men with prostate cancer after brachytherapy: Is dose to the penile bulb important?

    SciTech Connect (OSTI)

    Macdonald, A. Graham [Department of Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, Vancouver, BC (Canada)]. E-mail: gmacdonald@easynet.co.uk; Keyes, Mira [Department of Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, Vancouver, BC (Canada); Kruk, Alexandra [Department of Radiation Therapy, Vancouver Cancer Centre, BC Cancer Agency, Vancouver, BC (Canada); Duncan, Graeme [Department of Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, Vancouver, BC (Canada); Moravan, Veronika [Population and Preventive Oncology, BC Cancer Agency, Vancouver, BC (Canada); Morris, W. James [Department of Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, Vancouver, BC (Canada)

    2005-09-01T23:59:59.000Z

    Purpose: To determine predictive factors for postimplant erectile dysfunction (ED) in a cohort of patients, according to prospectively collected data; specifically, to assess the impact of penile bulb volume and D50 and D95 (dose covering 50% and 95% of the penile bulb volume, respectively) on ED. Methods and Materials: Three hundred forty-two patients were identified who were potent before implant and who had at least 2 years' follow-up. Patient, tumor, treatment, and dosimetric data were collected on all patients. Postimplant ED was defined according to both physician-documented and patient-documented outcome data. Binary logistic regression analysis was used to create multivariable models of predictors for ED at 1, 2, and 3 years after implant. Results: Physician-documented rates of ED were 57%, 48%, and 38% at 1, 2, and 3 years after implant, respectively. Patient-documented rates of ED were 70% and 66% at 1 and 2 years, respectively. Multivariable analyses revealed age and degree of preimplant erectile function to be consistently significant predictors of ED. Use of hormones was significant at the 1-year physician-documented ED endpoint but not thereafter, in keeping with the time course of testosterone recovery. Penile bulb volume, D50, and D95 were not found to be predictive for ED at any time point, in contrast to previous studies. In addition, planning ultrasound target volume, number of needles, and institutional case sequence number were significant predictors of ED at various time points, consistent with a traumatic etiology of ED. Conclusions: We found no evidence to support penile bulb dosimetry as an independent predictive factor for ED after implant, using physician-documented or patient-documented outcomes.

  8. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Golden, Jeffry

    2007-02-13T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  9. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Mincher, Bruce J. (3705 Creekside Dr., Idaho Falls, ID 83404); Curry, Randy Dale (1104 Merrill Ct., Columbia, MO 65203); Clevenger, Thomas E. (2512 Bluff Blvd., Columbia, MO 65201); Golden, Jeffry (12612 Cedarbrook La., Laurel, MD 20708)

    2000-01-01T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacting a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  10. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

    2003-05-27T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  11. Solitonic axion condensates modeling dark matter halos

    SciTech Connect (OSTI)

    Castañeda Valle, David, E-mail: casvada@gmail.com; Mielke, Eckehard W., E-mail: ekke@xanum.uam.mx

    2013-09-15T23:59:59.000Z

    Instead of fluid type dark matter (DM), axion-like scalar fields with a periodic self-interaction or some truncations of it are analyzed as a model of galaxy halos. It is probed if such cold Bose–Einstein type condensates could provide a viable soliton type interpretation of the DM ‘bullets’ observed by means of gravitational lensing in merging galaxy clusters. We study solitary waves for two self-interacting potentials in the relativistic Klein–Gordon equation, mainly in lower dimensions, and visualize the approximately shape-invariant collisions of two ‘lump’ type solitons. -- Highlights: •An axion model of dark matter is considered. •Collision of axion type solitons are studied in a two dimensional toy model. •Relations to dark matter collisions in galaxy clusters are proposed.

  12. Dynamical insight into dark-matter haloes

    E-Print Network [OSTI]

    Walter Dehnen; Dean McLaughlin

    2005-06-22T23:59:59.000Z

    We investigate, using the spherical Jeans equation, self-gravitating dynamical equilibria satisfying a relation rho/sigma_r^3 propto r^-alpha, which holds for simulated dark-matter haloes over their whole resolved radial range. Considering first the case of velocity isotropy, we find that this problem has only one solution with realistic density profile, which occurs only for a critical value of alpha_crit = 35/18 ~= 1.94, which is consistent with the empirical value of 1.9+/-0.05. We extend our analysis in two ways: first we introduce a parameter epsilon to allow for a more general relation rho/\\sigma_r^epsilon propto r^-alpha; second we consider velocity anisotropy. If we assume beta(r) := 1- sigma_theta^2 / sigma_r^2 to be linearly related to the logarithmic density slope gamma(r) := -dln(rho)/dln(r), which is in agreement with simulations, the problem remains analytically tractable and is equivalent to the simpler isotropic case: there exists only one physical solution, which occurs at a critical alpha value. Remarkably, this value of alpha and the density and velocity-dispersion profiles depend only on epsilon and the value beta_0 := beta(r=0), but not on the slope of the linear beta-gamma relation. For epsilon=3, alpha_crit = 35/18 - 2beta_0/9 and the resulting density profile is fully analytic (as are the velocity dispersion and circular speed) with an inner cusp rho propto r^{-(7+10beta_0)/9} and a very smooth transition to a steeper outer power-law asymptote. These models are in excellent agreement with the density, velocity-dispersion and anisotropy profiles of simulated dark-matter haloes over their full resolved radial range. If epsilon=3 is a universal constant, some scatter in beta_0 ~= 0 may account for some diversity in the density profiles. (ABRIDGED)

  13. Galactosynthesis: Halo Histories, Star Formation, and Disks

    E-Print Network [OSTI]

    Ari Buchalter; Raul Jimenez; Marc Kamionkowski

    2000-06-01T23:59:59.000Z

    We investigate the effects of a variety of ingredients that must enter into a realistic model for disk-galaxy formation, focusing primarily on the Tully-Fisher (TF) relation and its scatter in several wavebands. Our main findings are: (a) the slope, normalization, and scatter of the TF relation across various wavebands is determined {\\em both} by halo properties and star formation in the disk; (b) TF scatter owes primarily to the spread in formation redshifts. The scatter can be measurably reduced by chemical evolution, and also in some cases by the weak anti-correlation between peak height and spin; (c) multi-wavelength constraints can be important in distinguishing between models which appear to fit the TF relation in I or K; (d) successful models seem to require that the bulk of disk formation cannot occur too early (z>2) or too late (z<0.5), and are inconsistent with high values of $\\Omega_0$; (e) a realistic model with the above ingredients can reasonably reproduce the observed z=0 TF relation in {\\em all} bands (B, R, I, and K). It can also account for the z=1 B-band TF relation and yield rough agreement with the local B and K luminosity functions and B-band surface-brightness--magnitude relation. The remarkable agreement with observations suggests that the amount of gas that is expelled or poured into a disk galaxy must be small, and that the specific angular momentum of the baryons must roughly equal that of the halo; there is little room for angular momentum transfer. In an appendix we present analytic fits to stellar-population synthesis models.

  14. Contouring Variability of the Penile Bulb on CT Images: Quantitative Assessment Using a Generalized Concordance Index

    SciTech Connect (OSTI)

    Carillo, Viviana [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Cozzarini, Cesare [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy)] [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy); Perna, Lucia; Calandra, Mauro [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Gianolini, Stefano [Medical Software Solutions GmbH, Hagendorn (Switzerland)] [Medical Software Solutions GmbH, Hagendorn (Switzerland); Rancati, Tiziana [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy)] [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Spinelli, Antonello Enrico [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Vavassori, Vittorio [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy)] [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy); Villa, Sergio [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy)] [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Valdagni, Riccardo [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy) [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Fiorino, Claudio, E-mail: fiorino.claudio@hsr.it [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)

    2012-11-01T23:59:59.000Z

    Purpose: Within a multicenter study (DUE-01) focused on the search of predictors of erectile dysfunction and urinary toxicity after radiotherapy for prostate cancer, a dummy run exercise on penile bulb (PB) contouring on computed tomography (CT) images was carried out. The aim of this study was to quantitatively assess interobserver contouring variability by the application of the generalized DICE index. Methods and Materials: Fifteen physicians from different Institutes drew the PB on CT images of 10 patients. The spread of DICE values was used to objectively select those observers who significantly disagreed with the others. The analyses were performed with a dedicated module in the VODCA software package. Results: DICE values were found to significantly change among observers and patients. The mean DICE value was 0.67, ranging between 0.43 and 0.80. The statistics of DICE coefficients identified 4 of 15 observers who systematically showed a value below the average (p value range, 0.013 - 0.059): Mean DICE values were 0.62 for the 4 'bad' observers compared to 0.69 of the 11 'good' observers. For all bad observers, the main cause of the disagreement was identified. Average DICE values were significantly worse from the average in 2 of 10 patients (0.60 vs. 0.70, p < 0.05) because of the limited visibility of the PB. Excluding the bad observers and the 'bad' patients,' the mean DICE value increased from 0.67 to 0.70; interobserver variability, expressed in terms of standard deviation of DICE spread, was also reduced. Conclusions: The obtained values of DICE around 0.7 shows an acceptable agreement, considered the small dimension of the PB. Additional strategies to improve this agreement are under consideration and include an additional tutorial of the so-called bad observers with a recontouring procedure, or the recontouring by a single observer of the PB for all patients included in the DUE-01 study.

  15. Introduction The Fiber-Lite MI-150 is a 150 Watt quartz halogen fiber optic illuminator designed for general microscopy

    E-Print Network [OSTI]

    Kleinfeld, David

    Introduction ® The Fiber-Lite MI-150 is a 150 Watt quartz halogen fiber optic illuminator designed for general microscopy use. When used with specialty fiber optic cables the MI-150 illuminator can also Illuminator from the carton and retain the manual and any additional documents. ! Remove the fiber optic cable

  16. Simulating large cosmology surveys with calibrated halo models 

    E-Print Network [OSTI]

    Lynn, Stuart

    2011-11-23T23:59:59.000Z

    In this thesis I present a novel method for constructing large scale mock galaxy and halo catalogues and apply this model to a number of important topics in modern cosmology. Traditionally such mocks are created through ...

  17. Terminal Velocity Infall in QSO Absorption Line Halos

    E-Print Network [OSTI]

    Robert A. Benjamin

    1998-11-04T23:59:59.000Z

    We explore the hypothesis that clouds detected in quasar absorption line systems are falling at a terminal velocity toward the center of high redshift gaseous galactic halos. Since both the ionization level and terminal velocity of halo clouds increase with increasing distance from the central galaxy, velocity resolved profiles of highly ionized gas are predicted to have a greater width than low ionization gas. A line of sight passing through the center of gaseous halo (an idealized damped Ly alpha system), yields low ionization absorption at the velocity of the galaxy, flanked by high ionization on either side. Reasonable halo parameters yield total velocity extents for C IV of v_{C IV}=100-200 km/s, in agreement with several observed systems. The remaining systems may better described by the rotating disk model of Prochaska & Wolfe (1998). Finally, observational tests are suggested for verifying or falsifying the terminal velocity hypothesis for these systems.

  18. Palladium-Catalyzed Amination of Unprotected Halo-7- azaindoles

    E-Print Network [OSTI]

    Henderson, Jaclyn L.

    Simple and efficient procedures for the Pd-catalyzed cross-coupling of primary and secondary amines with halo-7-azaindoles(pyrrolo[2,3-b]pyridine) are presented. Previously, no general method was available to ensure the ...

  19. Possible existence of wormholes in the central regions of halos

    E-Print Network [OSTI]

    Farook Rahaman; P. Salucci; P. K. F. Kuhfittig; Saibal Ray; Mosiur Rahaman

    2015-01-05T23:59:59.000Z

    An earlier study [Rahaman et al. (2014) & Kuhfittig (2014)] has demonstrated the possible existence of wormholes in the outer regions of the galactic halo, based on the Navarro-Frenk-White (NFW) density profile. This paper uses the Universal Rotation Curve (URC) dark matter model to obtain analogous results for the central parts of the halo. This result is an important compliment to the earlier result, thereby confirming the possible existence of wormholes in most of the spiral galaxies.

  20. DUAL HALOS AND FORMATION OF EARLY-TYPE GALAXIES

    SciTech Connect (OSTI)

    Park, Hong Soo; Lee, Myung Gyoon, E-mail: hspark@astro.snu.ac.kr, E-mail: mglee@astro.snu.ac.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)

    2013-08-20T23:59:59.000Z

    We present a determination of the two-dimensional shape parameters of the blue and red globular cluster systems (GCSs) in a large number of elliptical galaxies and lenticular galaxies (early-type galaxies, called ETGs). We use a homogeneous data set of the globular clusters in 23 ETGs obtained from the HST/ACS Virgo Cluster Survey. The position angles of both blue and red GCSs show a correlation with those of the stellar light distribution, showing that the major axes of the GCSs are well aligned with those of their host galaxies. However, the shapes of the red GCSs show a tight correlation with the stellar light distribution as well as with the rotation property of their host galaxies, while the shapes of the blue GCSs do much less. These provide clear geometric evidence that the origins of the blue and red globular clusters are distinct and that ETGs may have dual halos: a blue (metal-poor) halo and a red (metal-rich) halo. These two halos show significant differences in metallicity, structure, and kinematics, indicating that they are formed in two distinguishable ways. The red halos might have formed via dissipational processes with rotation, while the blue halos are through accretion.

  1. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, Robert T. (Livermore, CA); Jackson, Kenneth J. (San Leandro, CA); Duba, Alfred G. (Livermore, CA); Chen, Ching-I (Danville, CA)

    1998-01-01T23:59:59.000Z

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

  2. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

    1998-05-19T23:59:59.000Z

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

  3. DO HOT HALOS AROUND GALAXIES CONTAIN THE MISSING BARYONS?

    SciTech Connect (OSTI)

    Anderson, Michael E.; Bregman, Joel N., E-mail: michevan@umich.ed, E-mail: jbregman@umich.ed [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)

    2010-05-01T23:59:59.000Z

    Galaxies are missing most of their baryons, and many models predict these baryons lie in a hot halo around galaxies. We establish observationally motivated constraints on the mass and radii of these halos using a variety of independent arguments. First, the observed dispersion measure of pulsars in the Large Magellanic Cloud allows us to constrain the hot halo around the Milky Way: if it obeys the standard Navarro, Frenk, and White (NFW) profile, it must contain less than 4%-5% of the missing baryons from the Galaxy. This is similar to other upper limits on the Galactic hot halo, such as the soft X-ray background and the pressure around high-velocity clouds. Second, we note that the X-ray surface brightness of hot halos with NFW profiles around large isolated galaxies is high enough that such emission should be observed, unless their halos contain less than 10%-25% of their missing baryons. Third, we place constraints on the column density of hot halos using nondetections of O VII absorption along active galactic nucleus (AGN) sightlines: in general they must contain less than 70% of the missing baryons or extend to no more than 40 kpc. Flattening the density profile of galactic hot halos weakens the surface brightness constraint so that a typical L{sub *} galaxy may hold half its missing baryons in its halo, but the O VII constraint remains unchanged, and around the Milky Way a flattened profile may only hold 6%-13% of the missing baryons from the Galaxy ((2-4) x 10{sup 10} M{sub sun}). We also show that AGN and supernovae at low to moderate redshift-the theoretical sources of winds responsible for driving out the missing baryons-do not produce the expected correlations with the baryonic Tully-Fisher relationship and, therefore, are insufficient to explain the missing baryons from galaxies. We conclude that most of missing baryons from galaxies do not lie in hot halos around the galaxies, and that the missing baryons never fell into the potential wells of protogalaxies in the first place. They may have been expelled from the galaxies as part of the process of galaxy formation.

  4. Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the Observed Eddington Ratio Distribution

    E-Print Network [OSTI]

    Philip F. Hopkins; Lars Hernquist

    2009-04-30T23:59:59.000Z

    We use the observed distribution of Eddington ratios as a function of supermassive black hole (BH) mass to constrain models of AGN lifetimes and lightcurves. Given the observed AGN luminosity function, a model for AGN lifetimes (time above a given luminosity) translates directly to a predicted Eddington ratio distribution. Models for self-regulated BH growth, in which feedback produces a 'blowout' decay phase after some peak luminosity (shutting down accretion) make specific predictions for the lifetimes distinct from those expected if AGN are simply gas starved (without feedback) and very different from simple phenomenological 'light bulb' models. Present observations of the Eddington ratio distribution, spanning 5 decades in Eddington ratio, 3 in BH mass, and redshifts z=0-1, agree with the predictions of self-regulated models, and rule out 'light-bulb', pure exponential, and gas starvation models at high significance. We compare the Eddington ratio distributions at fixed BH mass and fixed luminosity (both are consistent, but the latter are much less constraining). We present empirical fits to the lifetime distribution and show how the Eddington ratio distributions place tight limits on AGN lifetimes at various luminosities. We use this to constrain the shape of the typical AGN lightcurve, and provide simple analytic fits. Given independent constraints on episodic lifetimes, most local BHs must have gained their mass in no more than a couple of bright episodes, in agreement with merger-driven fueling models.

  5. Bar-halo Friction in Galaxies I: Scaling Laws

    E-Print Network [OSTI]

    J. A. Sellwood

    2005-09-28T23:59:59.000Z

    It has been known for some time that rotating bars in galaxies slow due to dynamical friction against the halo. However, recent attempts to use this process to place constraints on the dark matter density in galaxies and possibly also to drive dark matter out of the center have been challenged. This paper uses simplified numerical experiments to clarify several aspects of the friction mechanism. I explicitly demonstrate the Chandrasekhar scaling of the friction force with bar mass, halo density, and halo velocity dispersion. I present direct evidence that exchanges between the bar and halo orbits at major resonances are responsible for friction and study both individual orbits and the net changes at these resonances. I also show that friction alters the phase space density of particles in the vicinity of a major resonance, which is the reason the magnitude of the friction force depends on the prior evolution. I demonstrate that bar slow down can be captured correctly in simulations having modest spatial resolution and practicable numbers of particles. Subsequent papers in this series delineate the dark matter density that can be tolerated in halos of different density profiles.

  6. Bar-Halo Friction in Galaxies II: Metastability

    E-Print Network [OSTI]

    J. A. Sellwood; Victor P. Debattista

    2005-11-05T23:59:59.000Z

    It is well-established that strong bars rotating in dense halos generally slow down as they lose angular momentum to the halo through dynamical friction. Angular momentum exchanges between the bar and halo particles take place at resonances. While some particles gain and others lose, friction arises when there is an excess of gainers over losers. This imbalance results from the generally decreasing numbers of particles with increasing angular momentum, and friction can therefore be avoided if there is no gradient in the density of particles across the major resonances. Here we show that anomalously weak friction can occur for this reason if the pattern speed of the bar fluctuates upwards. After such an event, the density of resonant halo particles has a local inflexion created by the earlier exchanges, and bar slowdown can be delayed for a long period; we describe this as a metastable state. We show that this behavior in purely collisionless N-body simulations is far more likely to occur in methods with adaptive resolution. We also show that the phenomenon could arise in nature, since bar-driven gas inflow could easily raise the bar pattern speed enough to reach the metastable state. Finally, we demonstrate that mild external, or internal, perturbations quickly restore the usual frictional drag, and it is unlikely therefore that a strong bar in a galaxy having a dense halo could rotate for a long period without friction.

  7. Investigation of the Contamination of the Gould (2003) Halo Sample

    E-Print Network [OSTI]

    Andrew Gould

    2007-08-09T23:59:59.000Z

    A recent astroph posting argued that the Gould (2003a) halo sample is substantially contaminated with thick-disk stars, which would then ``wash out'' any signature of granularity in the halo velocity distribution due to streams. If correct, this would imply that the limits placed by Gould (2003b) on streams are not valid. Here I investigate such contamination using six different indicators: (1) morphology of the underlying reduced proper motion diagram used to select halo stars; (2) comparison of kinematic and parallax-based distance scales; (3) comparison of derived halo parameters for the Gould (2003a) sample with other determinations; (4) a precision color-color diagram for a random subsample; (5) the 3-dimensional velocity distribution of a random subsample; (6) metallicity distribution versus kinematic cuts on a random subsample. I estimate that the contamination is of order 2%. Thus, the upper limits on the density of nearby streams derived by Gould (2003b) remain valid. In particular, at 95% confidence, no more than 5% of local halo stars (within about 300 pc) are in any one coherent stream. Determining whether or not this local measurement is consistent with CDM remains an outstanding question.

  8. The orientation of galaxy dark matter haloes around cosmic voids

    E-Print Network [OSTI]

    Riccardo Brunino; Ignacio Trujillo; Frazer R. Pearce; Peter A. Thomas

    2006-11-10T23:59:59.000Z

    Using the Millennium N-body simulation we explore how the shape and angular momentum of galaxy dark matter haloes surrounding the largest cosmological voids are oriented. We find that the major and intermediate axes of the haloes tend to lie parallel to the surface of the voids, whereas the minor axis points preferentially in the radial direction. We have quantified the strength of these alignments at different radial distances from the void centres. The effect of these orientations is still detected at distances as large as 2.2 R_void from the void centre. Taking a subsample of haloes expected to contain disc-dominated galaxies at their centres we detect, at the 99.9% confidence level, a signal that the angular momentum of those haloes tends to lie parallel to the surface of the voids. Contrary to the alignments of the inertia axes, this signal is only detected in shells at the void surface (1haloes and baryonic matter have acquired, conjointly, their angular momentum before the moment of turnaround.

  9. Environment Dependence of Dark Matter Halos in Symmetron Modified Gravity

    E-Print Network [OSTI]

    Hans A. Winther; David F. Mota; Baojiu Li

    2011-10-28T23:59:59.000Z

    We investigate the environment dependence of dark matter halos in the symmetron modified gravity scenario. The symmetron is one of three known mechanisms for screening a fifth-force and thereby recovering General Relativity in dense environments. The effectiveness of the screening depends on both the mass of the object and the environment it lies in. Using high-resolution N-body simulations we find a significant difference, which depends on the halos mass and environment, between the lensing and dynamical masses of dark matter halos similar to the f(R) modified gravity. The symmetron can however yield stronger signatures due to a freedom in the strength of the coupling to matter.

  10. Suppressed fusion cross section for neutron halo nuclei

    E-Print Network [OSTI]

    Makoto Ito; Kazuhiro Yabana; Takashi Nakatsukasa; Manabu Ueda

    2006-01-20T23:59:59.000Z

    Fusion reactions of neutron-halo nuclei are investigated theoretically with a three-body model. The time-dependent wave-packet method is used to solve the three-body Schrodinger equation. The halo neutron behaves as a spectator during the Coulomb dissociation process of the projectile. The fusion cross sections of 11Be-209Bi and 6He-238U are calculated and are compared with measurements. Our calculation indicates that the fusion cross section is slightly hindered by the presence of weakly bound neutrons.

  11. Dark Matter Halos as Bose-Einstein Condensates

    E-Print Network [OSTI]

    Eckehard W. Mielke; Burkhard Fuchs; Franz E. Schunck

    2006-08-24T23:59:59.000Z

    Galactic dark matter is modelled by a scalar field in order to effectively modify Kepler's law without changing standard Newtonian gravity. In particular, a solvable toy model with a self-interaction U(Phi) borrowed from non-topological solitons produces already qualitatively correct rotation curves and scaling relations. Although relativistic effects in the halo are very small, we indicate corrections arising from the general relativistic formulation. Thereby, we can also probe the weak gravitational lensing of our soliton type halo. For cold scalar fields, it corresponds to a gravitationally confined Boson-Einstein condensate, but of galactic dimensions.

  12. Determination of the 1%, 2.5%, and 5% occurrences of extreme dew-point temperatures and mean coincident dry-bulb temperatures

    SciTech Connect (OSTI)

    Colliver, D.G.; Zhang, H.; Gates, R.; Priddy, T. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-31T23:59:59.000Z

    The purpose of ASHRAE Research Project RP-754 was to find the outdoor design occurrences of extreme dew-point temperature and the corresponding mean coincident dry-bulb temperature for a large number of locations in North America. Thirty years of data (1961--1990) were used for 239 US locations, and the last 30 years of hourly data available (typically 1960--1989) were used for 143 Canadian locations. Tables are given that present the 1%, 2.5%, and 5% extreme summertime occurrences of dew-point temperatures and corresponding values of humidity ratios and the mean coincident dry-bulb (MCDB) temperature for the period of record. A map that shows the general geographical trends for the spatial distribution of the design dew-point values is also presented. Comparisons are provided between interpolation techniques to fill missing data, different weather data sets, and methods of calculating different definitions of extreme design and mean coincident data. Results are also reported of a comparison to evaluate the difference in humidity ratios between that calculated from the extreme design dry-bulb temperature and mean coincident wet-bulb temperature, versus that calculated from the extreme design dew-point temperature and the MCDB. It was found that the method of extreme dew point with MCDB had a higher humidity ratio that was on the average (for the 1% case and the 239 US locations) 0.00564 lb/lb larger than the humidity ratio found with the other method.

  13. Electrical Appliances Students may use clocks, sound equipment, computers, electric razors, hair dryers,

    E-Print Network [OSTI]

    Aalberts, Daniel P.

    with a heating coil *Torchiere type lamps with a halogen bulb, and other lamps with a halogen bulb greater than there is specific UL approval for a higher wattage. Violators of any of the above policies will be charged $50, Prohibited Appliances, and Halogen Torchiere Lamps 1st offense: $50.00 fine and the student will be called

  14. Breaking the symmetries of the bulb model in two-dimensional self-induced supernova neutrino flavor conversions

    E-Print Network [OSTI]

    Mirizzi, Alessandro

    2015-01-01T23:59:59.000Z

    Self-induced flavor conversions of supernova (SN) neutrinos have been characterized in the spherically symmetric "bulb model", reducing the neutrino evolution to a one dimensional problem along a radial direction. We lift this assumption, presenting a two-dimensional model where neutrinos are launched from a spherical neutrino-sphere with many zenithal angles and two azimuthal angles. We also assume that self-induced conversions are not suppressed by large matter effects. In this situation we find that self-interacting neutrinos spontaneously break axial and spherical symmetries. As a result the flavor content and the lepton number of the neutrino gas would acquire seizable direction-dependent variations, breaking the coherent behavior found in the spherically symmetric case. This finding would suggest that the previous results of the self-induced flavor evolution obtained in one-dimensional models should be critically re-examined.

  15. Determination of heavy metals and halogens in plastics from electric and electronic waste

    SciTech Connect (OSTI)

    Dimitrakakis, Emmanouil [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, University Campus, 73100 Chania (Greece); Janz, Alexander; Bilitewski, Bernd [Institute for Waste Management and Contaminated Site Treatment, Dresden University of Technology, Pratzschwitzerstrasse 15, 01796 Pirna (Germany); Gidarakos, Evangelos [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, University Campus, 73100 Chania (Greece)], E-mail: gidarako@mred.tuc.gr

    2009-10-15T23:59:59.000Z

    The presence of hazardous substances and preparations in small waste electrical and electronic equipment (sWEEE) found in the residual household waste stream of the city of Dresden, Germany has been investigated. The content of sWEEE plastics in heavy metals and halogens is determined using handheld X-ray fluorescence analysis (HXRF), elemental analysis by means of atomic absorption spectrometry (AAS) and ion exchange chromatography (IEC). Mean value of results for heavy metals in samples (n = 51) by AAS are 17.4 mg/kg for Pb, 5.7 mg/kg for Cd, 8.4 mg/kg for Cr. The mass fraction of an additive as shown by HXRF (n = 161) can vary over a wide range. Precise deductions as regards sWEEE plastics content in hazardous substances and preparations cannot be made. Additional research would be expedient regarding the influence of hazardous substances to recycling processes, in particular regarding the contamination of clean fractions in the exit streams of a WEEE treatment plant. Suitable standards for calibrating HXRF for use on EEE plastics or complex electr(on)ic components do not exist and should be developed.

  16. A continuous fast-response dual-tracer analyzer for halogenated atmospheric tracer studies

    SciTech Connect (OSTI)

    Rydock, J.P.; Lamb, B.K. [Washington State Univ., Pullman, WA (United States)] [Washington State Univ., Pullman, WA (United States)

    1994-10-01T23:59:59.000Z

    An apparatus for the simultaneous measurement of two tracers, sulfur hexafluoride (SF6) and a perfluorocarbon compound, is introduced. The new instrument is a modification of a commercially available fast-response, continuous analyzer for single halogenated atmospheric tracer studies. A two-channel flow system was implemented consisting of an alumina cartridge in one channel and a glass beads cartridge of equal flow resistance in the second channel. The alumina passes only sulfur hexafluoride, while the glass beads pass both SF6 and the perfluoroarbon tracer. The SF6 is quantified directly from the electron capture detector (ECD) signal in the alumina channel, and the perfluorocarbon concentration is obtained from the difference of the ECD responses in the two channels. The dual-tracer analyzer is field portable for mobile operations or fixed-location monitoring, has a response time of 1.2 s, and has limits of detection of about 15 pptv for SF6 and 10 pptv for perfluoro-methylcyclohexane, which was the principal perfluorocarbon tracer used in this study. The present instrument configuration, which requires periodic purging of the adsorbent trap, can obtain continuous measurements for a 10-15-min segment in every half hour of operation. Dual-tracer data from a field demonstration test are presented.

  17. Instrument uncertainty effect on calculation of absolute humidity using dewpoint, wet-bulb, and relative humidity sensors

    SciTech Connect (OSTI)

    Slayzak, S.J.; Ryan, J.P.

    1998-04-01T23:59:59.000Z

    As part of the US Department of Energy`s Advanced Desiccant Technology Program, the National Renewable Energy Laboratory (NREL) is characterizing the state-of-the-art in desiccant dehumidifiers, the key component of desiccant cooling systems. The experimental data will provide industry and end users with independent performance evaluation and help researchers assess the energy savings potential of the technology. Accurate determination of humidity ratio is critical to this work and an understanding of the capabilities of the available instrumentation is central to its proper application. This paper compares the minimum theoretical random error in humidity ratio calculation for three common measurement methods to give a sense of the relative maximum accuracy possible for each method assuming systematic errors can be made negligible. A series of experiments conducted also illustrate the capabilities of relative humidity sensors as compared to dewpoint sensors in measuring the grain depression of desiccant dehumidifiers. These tests support the results of the uncertainty analysis. At generally available instrument accuracies, uncertainty in calculated humidity ratio for dewpoint sensors is determined to be constant at approximately 2%. Wet-bulb sensors range between 2% and 6% above 10 g/kg (4%--15% below), and relative humidity sensors vary between 4% above 90% rh and 15% at 20% rh. Below 20% rh, uncertainty for rh sensors increases dramatically. Highest currently attainable accuracies bring dewpoint instruments down to 1% uncertainty, wet bulb to a range of 1%--3% above 10 g/kg (1.5%--8% below), and rh sensors between 1% and 5%.

  18. Neutron-Capture Element Trends in the Halo

    E-Print Network [OSTI]

    C. Sneden; J. J. Cowan; J. W. Truran

    2001-01-24T23:59:59.000Z

    In a brief review of abundances neutron-capture elements (Z > ~30) in metal-poor halo stars, attention is called to their star-to-star scatter, the dominance of r-process synthesis at lowest metallicities, the puzzle of the lighter members of this element group, and the possibility of a better r-/s-process discriminant.

  19. The Star Formation History in the Andromeda Halo

    E-Print Network [OSTI]

    Thomas M. Brown

    2003-08-18T23:59:59.000Z

    I present the preliminary results of a program to measure the star formation history in the halo of the Andromeda galaxy. Using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope, we obtained the deepest optical images of the sky to date, in a field on the southeast minor axis of Andromeda, 51 arcmin (11 kpc) from the nucleus. The resulting color-magnitude diagram (CMD) contains approximately 300,000 stars and extends more than 1.5 mag below the main sequence turnoff, with 50% completeness at V=30.7 mag. We interpret this CMD using comparisons to ACS observations of five Galactic globular clusters through the same filters, and through chi-squared fitting to a finely-spaced grid of calibrated stellar population models. We find evidence for a major (approximately 30%) intermediate-age (6-8 Gyr) metal-rich ([Fe/H] > -0.5) population in the Andromeda halo, along with a significant old metal-poor population akin to that in the Milky Way halo. The large spread in ages suggests that the Andromeda halo formed as a result of a more violent merging history than that in our own Milky Way.

  20. HOT GAS HALOS IN EARLY-TYPE FIELD GALAXIES

    SciTech Connect (OSTI)

    Mulchaey, John S. [Observatories of the Carnegie Institution of Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Jeltema, Tesla E., E-mail: mulchaey@obs.carnegiescience.ed, E-mail: tesla@ucolick.or [UCO/Lick Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2010-05-20T23:59:59.000Z

    We use Chandra and XMM-Newton to study the hot gas content in a sample of field early-type galaxies. We find that the L {sub X}-L {sub K} relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. The low hot gas content of field galaxies with L {sub K} {approx_lt} L {sub *} suggests that internal processes such as supernovae-driven winds or active galactic nucleus feedback expel hot gas from low-mass galaxies. Such mechanisms may be less effective in groups and clusters where the presence of an intragroup or intracluster medium can confine outflowing material. In addition, galaxies in groups and clusters may be able to accrete gas from the ambient medium. While there is a population of L {sub K} {approx_lt} L {sub *} galaxies in groups and clusters that retain hot gas halos, some galaxies in these rich environments, including brighter galaxies, are largely devoid of hot gas. In these cases, the hot gas halos have likely been removed via ram pressure stripping. This suggests a very complex interplay between the intragroup/intracluster medium and hot gas halos of galaxies in rich environments, with the ambient medium helping to confine or even enhance the halos in some cases and acting to remove gas in others. In contrast, the hot gas content of more isolated galaxies is largely a function of the mass of the galaxy, with more massive galaxies able to maintain their halos, while in lower mass systems the hot gas escapes in outflowing winds.

  1. Self-enrichment of Galactic halo globular clusters: stimulated star formation and consequences for the halo metallicity distribution

    E-Print Network [OSTI]

    Genevieve Parmentier

    2004-03-10T23:59:59.000Z

    We explore the self-enrichment hypothesis for globular cluster formation with respect to the star formation aspect. Following this scenario, the massive stars of a first stellar generation chemically enrich the globular progenitor cloud up to Galactic halo metallicities and sweep it into an expanding spherical shell of gas. This paper investigates the ability of this swept proto-globular cloud to become gravitationally unstable and, therefore, to seed the formation of second generation stars which may later on form a globular cluster. We use a simple model based on a linear perturbation theory for transverse motions in a shell of gas to demonstrate that the pressures by which the progenitor clouds are bound and the supernova numbers required to achieve Galactic halo metallicities support the successful development of the shell transverse collapse. Interestingly, the two parameters controling the metallicity achieved through self-enrichment, namely the number of supernovae and the external pressure, also rule the surface density of the shell and thus its ability to undergo a transverse collapse. Such a supernova-induced origin for the globular cluster stars opens therefore the way to the understanding of the halo metallicity distributions. This model is also able to explain the lower limit of the halo globular cluster metallicity.

  2. Density waves in the shearing sheet IV. Interaction with a live dark halo

    E-Print Network [OSTI]

    B. Fuchs

    2004-03-01T23:59:59.000Z

    It is shown that if the self-gravitating shearing sheet, a model of a patch of a galactic disk, is embedded in a live dark halo, this has a strong effect on the dynamics of density waves in the sheet. I describe how the density waves and the halo interact via halo particles either on orbits in resonance with the wave or on non-resonant orbits. Contrary to expectation the presence of the halo leads to a very considerable enhancement of the amplitudes of the density waves in the shearing sheet. This effect appears to be the equivalent of the recently reported enhanced growth of bars in numerically simulated stellar disks embedded in live dark halos. Finally I discuss the transfer of linear momentum from a density wave in the sheet to the halo and show that it is mediated only by halo particles on resonant orbits.

  3. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOE Patents [OSTI]

    Kansa, Edward J. (Livermore, CA); Anderson, Brian L. (Lodi, CA); Wijesinghe, Ananda M. (Tracy, CA); Viani, Brian E. (Oakland, CA)

    1999-01-01T23:59:59.000Z

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced.

  4. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOE Patents [OSTI]

    Kansa, E.J.; Anderson, B.L.; Wijesinghe, A.M.; Viani, B.E.

    1999-05-25T23:59:59.000Z

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced. 3 figs.

  5. The Milky Way's stellar halo - lumpy or triaxial?

    E-Print Network [OSTI]

    Heidi Jo Newberg; Brian Yanny

    2005-07-28T23:59:59.000Z

    We present minimum chi-squared fits of power law and Hernquist density profiles to F-turnoff stars in eight 2.5 deg wide stripes of SDSS data: five in the North Galactic Cap and three in the South Galactic cap. Portions of the stellar Galactic halo that are known to contain large streams of tidal debris or other lumpy structure, or that may include significant contamination from the thick disk, are avoided. The data strongly favor a model that is not symmetric about the Galaxy's axis of rotation. If included as a free parameter, the best fit to the center of the spheroid is surprisingly approx 3 kpc from the Galactic center in the direction of the Sun's motion. The model fits favor a low value of the density of halo stars at the solar position. The alternative to a non-axisymmetric stellar distribution is that our fits are contaminated by previously unidentified lumpy substructure.

  6. Evidence in Virgo for the Universal Dark Matter Halo

    E-Print Network [OSTI]

    Dean E. McLaughlin

    1998-12-12T23:59:59.000Z

    A model is constructed for the mass and dynamics of M87 and the Virgo Cluster. Existing surface photometry of the galaxy, mass estimates from X-ray observations of the hot intracluster gas, and the velocity dispersions of early-type Virgo galaxies, all are used to constrain the run of dark matter density over radii to 2 Mpc in the cluster. The ``universal'' halo advocated by Navarro, Frenk, & White provides an excellent description of the combined data, as does a Hernquist profile. These models are favored over isothermal spheres, and their central structure is preferred to density cusps either much stronger or much weaker than r^{-1}. The galaxies and gas in the cluster trace its total mass distribution, the galaxies' velocity ellipsoid is close to isotropic, and the gas temperature follows the virial temperature profile of the dark halo. The virial radius and mass and the intracluster gas fraction of Virgo are evaluated.

  7. Dark energy parameterizations and their effect on dark halos

    E-Print Network [OSTI]

    Lamartine Liberato; Rogerio Rosenfeld

    2006-04-19T23:59:59.000Z

    There is a plethora of dark energy parameterizations that can fit current supernovae Ia data. However, this data is only sensitive to redshifts up to order one. In fact, many of these parameterizations break down at higher redshifts. In this paper we study the effect of dark energy models on the formation of dark halos. We select a couple of dark energy parameterizations which are sensible at high redshifts and compute their effect on the evolution of density perturbations in the linear and non-linear regimes. Using the Press-Schechter formalism we show that they produce distinguishable signatures in the number counts of dark halos. Therefore, future observations of galaxy clusters can provide complementary constraints on the behavior of dark energy.

  8. Inverted lVIicroscope DIAPHOT-TMD

    E-Print Network [OSTI]

    Kleinfeld, David

    lamp bulb to be used is 12V- 50W. Do not use 12V-l00W halogen lamp bulb. If the lamp bulb of over the lamp is being lighted. o Exchanging the lamp bulb and fuse Before replacing the lamp bulb or fuse, turn as of replacement, do not touch. the lamp bulb with bare hands, immediately after putting out the lamp. 2 Dirt

  9. ON THE HOT GAS CONTENT OF THE MILKY WAY HALO

    SciTech Connect (OSTI)

    Fang, Taotao [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)] [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Bullock, James; Boylan-Kolchin, Michael [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States)] [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States)

    2013-01-01T23:59:59.000Z

    The Milky Way appears to be missing baryons, as the observed mass in stars and gas is well below the cosmic mean. One possibility is that a substantial fraction of the Galaxy's baryons are embedded within an extended, million-degree hot halo, an idea supported indirectly by observations of warm gas clouds in the halo and gas-free dwarf spheroidal satellites. X-ray observations have established that hot gas does exist in our Galaxy beyond the local hot bubble; however, it may be distributed in a hot disk configuration. Moreover, recent investigations into the X-ray constraints have suggested that any Galactic corona must be insignificant. Here we re-examine the observational data, particularly in the X-ray and radio bands, in order to determine whether it is possible for a substantial fraction of the Galaxy's baryons to exist in {approx}10{sup 6} K gas. In agreement with past studies, we find that a baryonically closed halo is clearly ruled out if one assumes that the hot corona is distributed with a cuspy Navarro-Frenk-White profile. However, if the hot corona of the galaxy is in an extended, low-density distribution with a large central core, as expected for an adiabatic gas in hydrostatic equilibrium, then it may contain up to 10{sup 11} M {sub Sun} of material, possibly accounting for all of the missing Galactic baryons. We briefly discuss some potential avenues for discriminating between a massive, extended hot halo and a local hot disk.

  10. The Dark Matter halo of the Milky Way, AD 2013

    SciTech Connect (OSTI)

    Nesti, Fabrizio [Gran Sasso Science Institute, viale Crispi 7, I-67100 L'Aquila (Italy); Salucci, Paolo, E-mail: nesti@aquila.infn.it, E-mail: salucci@sissa.it [Scuola Internazionale Superiore di Studi Avanzati (SISSA/ISAS), Via Bonomea 265, I-34136 Trieste (Italy)

    2013-07-01T23:59:59.000Z

    We derive the mass model of the Milky Way (MW), crucial for Dark Matter (DM) direct and indirect detection, using recent data and a cored dark matter (DM) halo profile, which is favoured by studies of external galaxies. The method used consists in fitting a spherically symmetric model of the Galaxy with a Burkert DM halo profile to available data: MW terminal velocities in the region inside the solar circle, circular velocity as recently estimated from maser star forming regions at intermediate radii, and velocity dispersions of stellar halo tracers for the outermost Galactic region. The latter are reproduced by integrating the Jeans equation for every modeled mass distribution, and by allowing for different velocity anisotropies for different tracer populations. For comparison we also consider a Navarro-Frenk-White profile. We find that the cored profile is the preferred one, with a shallow central density of ?{sub H} ? 4 × 10{sup 7}M{sub ?}/kpc{sup 3} and a large core radius R{sub H} ? 10 kpc, as observed in external spirals and in agreement with the mass model underlying the Universal Rotation Curve of spirals. We describe also the derived model uncertainties, which are crucially driven by the poorly constrained velocity dispersion anisotropies of halo tracers. The emerging cored DM distribution has implications for the DM annihilation angular profile, which is much less boosted in the Galactic center direction with respect to the case of the standard ?CDM, NFW profile. Using the derived uncertainties we discuss finally the limitations and prospects to discriminate between cored and cusped DM profile with a possible observed diffuse DM annihilation signal. The present mass model aims to characterize the present-day description of the distribution of matter in our Galaxy, which is needed to frame current crucial issues of Cosmology, Astrophysics and Elementary Particles.

  11. Radius of B-8 halo from the asymptotic normalization coefficient

    E-Print Network [OSTI]

    Carstoiu, F.; Trache, L.; Gagliardi, Carl A.; Tribble, Robert E.; Mukhamedzhanov, AM.

    2001-01-01T23:59:59.000Z

    of Coulomb and centrifugal barriers. Many experiments have been devoted to studies of 8B in order to establish its halo nature. These include the determination of the interaction cross section @1,2#, quasi- elastic scattering @3#, reaction cross section... @4,5#, electric quadrupole moment @6#, nuclear breakup @5,7#, and Coulomb dissociation @8?10#. Interaction and reaction cross section measurements are particularly important since these observ- ables can be directly related to the nuclear size...

  12. A Critical Examination of Halo White Dwarf Candidates

    E-Print Network [OSTI]

    P. Bergeron

    2002-11-26T23:59:59.000Z

    A detailed analysis of halo white dwarf candidates is presented, which is based on model atmosphere fits to observed energy distributions built from photoelectric or photographic magnitudes. Most of the candidates identified in reduced proper motion diagrams are shown to be too warm (Teff > 5000 K) and most likely too young to be members of the galactic halo, while the tangential velocities of the cooler and thus older white dwarfs are shown to be entirely consistent with the disk population. The results suggest that some white dwarf stars born in the young disk may have high velocities with respect to the local standard of rest. Such objects could represent the remnants of donor stars from close mass-transfer binaries that produced type Ia supernovae via the single degenerate channel, or other scenarios suggested in the literature. Ongoing surveys that rely solely on reduced proper motion diagrams are likely to identify more of these high velocity young degenerates, rather than to unveil the old white dwarf population of the galactic halo. The importance of infrared photometry for studying extremely cool white dwarfs is also emphasized.

  13. Halo Luminosity Function From Photometric Calibration of the Revised NLTT

    E-Print Network [OSTI]

    Andrew Gould; Juna A. Kollmeier; Julio Chaname; Samir Salim

    2004-12-30T23:59:59.000Z

    We calibrate the photographic photometry of the revised New Luyten Two-Tenths catalog (rNLTT) by matching 3448 rNLTT stars to the Sloan Digital Sky Survey (SDSS). The correction is linear in magnitude and goes from zero at V ~ 14 to 0.32 mag at V=19, in the sense that rNLTT was previously too bright. The correction implies that the underlying USNO-A2.0 photometry, on which rNLTT photometry is based, is non-linear. The new calibration somewhat improves the appearance of the (V,V-J) reduced proper motion diagram in the sense of better separation between disk and halo stars. We repeat Gould's analysis of 5000 halo stars in rNLTT. The most important change is to move the peak of the halo luminosity function about 0.5 mag dimmer, from M_V=10.5 to M_V=11, putting it into good agreement with the parallax-based determination of Dahn et al.

  14. Merger Histories of Galaxy Halos and Implications for Disk Survival

    SciTech Connect (OSTI)

    Stewart, Kyle R.; Bullock, James S.; Wechsler, Risa H.; Maller, Ariyeh H.; Zentner, Andrew R.

    2008-05-16T23:59:59.000Z

    The authors study the merger histories of galaxy dark matter halos using a high resolution {Lambda}CDM N-body simulation. The merger trees follow {approx} 17,000 halos with masses M{sub 0} = (10{sup 11} - 10{sup 13})h{sup -1}M{sub {circle_dot}} at z = 0 and track accretion events involving objects as small as m {approx_equal} 10{sup 10} h{sup -1}M{sub {circle_dot}}. They find that mass assembly is remarkably self-similar in m/M{sub 0}, and dominated by mergers that are {approx}10% of the final halo mass. While very large mergers, m {approx}> 0.4 M{sub 0}, are quite rare, sizeable accretion events, m {approx} 0.1 M{sub 0}, are common. Over the last {approx} 10 Gyr, an overwhelming majority ({approx} 95%) of Milky Way-sized halos with M{sub 0} = 10{sup 12} h{sup -1}M{sub {circle_dot}} have accreted at least one object with greater total mass than the Milky Way disk (m > 5 x 10{sup 10} h{sup -1}M{sub {circle_dot}}), and approximately 70% have accreted an object with more than twice that mass (m > 10{sup 11} h{sup -1}M{sub {circle_dot}}). The results raise serious concerns about the survival of thin-disk dominated galaxies within the current paradigm for galaxy formation in a {Lambda}CDM universe. in order to achieve a {approx} 70% disk-dominated fraction in Milky Way-sized {Lambda}CDM halos, mergers involving m {approx_equal} 2 x 10{sup 11} h{sup -1}M{sub {circle_dot}} objects must not destroy disks. Considering that most thick disks and bulges contain old stellar populations, the situation is even more restrictive: these mergers must not heat disks or drive gas into their centers to create young bulges.

  15. Halos in a deformed relativistic Hartree-Bogoliubov theory in continuum

    SciTech Connect (OSTI)

    Li Lulu; Meng Jie; Ring, P.; Zhao Enguang; Zhou Shangui [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China) and Department of Physics, University of Stellenbosch, Stellenbosch (South Africa); Physikdepartment, Technische Universitaet Muenchen, 85748 Garching (Germany) and State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China) and Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China)

    2012-10-20T23:59:59.000Z

    In this contribution we present some recent results about neutron halos in deformed nuclei. A deformed relativistic Hartree-Bogoliubov theory in continuumhas been developed and the halo phenomenon in deformed weakly bound nuclei is investigated. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nuclei {sup 42}Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.

  16. There Is No Correlation Between Erectile Dysfunction and Dose to Penile Bulb and Neurovascular Bundles Following Real-Time Low-Dose-Rate Prostate Brachytherapy

    SciTech Connect (OSTI)

    Solan, Amy N. [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)], E-mail: amy.solan@mountsinai.org; Cesaretti, Jamie A. [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States); Stone, Nelson N. [Department of Urology, Mount Sinai School of Medicine, New York, NY (United States); Stock, Richard G. [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)

    2009-04-01T23:59:59.000Z

    Purpose: We evaluated the relationship between the onset of erectile dysfunction and dose to the penile bulb and neurovascular bundles (NVBs) after real-time ultrasound-guided prostate brachytherapy. Methods and Materials: One hundred forty-seven patients who underwent prostate brachytherapy met the following eligibility criteria: (1) treatment with {sup 125}I brachytherapy to a prescribed dose of 160 Gy with or without hormones without supplemental external beam radiation therapy, (2) identification as potent before the time of implantation based on a score of 2 or higher on the physician-assigned Mount Sinai Erectile Function Score and a score of 16 or higher on the abbreviated International Index of Erectile Function patient assessment, and (3) minimum follow-up of 12 months. Median follow-up was 25.7 months (range, 12-47 months). Results: The 3-year actuarial rate of impotence was 23% (34 of 147 patients). An additional 43% of potent patients (49 of 113 patients) were using a potency aid at last follow-up. The penile bulb volume receiving 100% of the prescription dose (V{sub 100}) ranged from 0-0.05 cc (median, 0 cc), with a dose to the hottest 5% (D{sub 5}) range of 12.5-97.9 Gy (median, 40.8 Gy). There was no correlation between penile bulb D{sub 5} or V{sub 100} and postimplantation impotency on actuarial analysis. For the combined right and left NVB structures, V{sub 100} range was 0.3-5.1 cc (median, 1.8 cc), and V{sub 150} range was 0-1.5 cc (median, 0.31 cc). There was no association between NVB V{sub 100} or V{sub 150} and postimplantation impotency on actuarial analysis. Conclusion: Penile bulb doses are low after real-time ultrasound-guided prostate brachytherapy. We found no correlation between dose to either the penile bulb or NVBs and the development of postimplantation impotency.

  17. Beta delayed emission of a proton by a one-neutron halo nucleus

    E-Print Network [OSTI]

    D. Baye; E. M. Tursunov

    2010-12-28T23:59:59.000Z

    Some one-neutron halo nuclei can emit a proton in a beta decay of the halo neutron. The branching ratio towards this rare decay mode is calculated within a two-body potential model of the initial core+neutron bound state and final core+proton scattering states. The decay probability per second is evaluated for the $^{11}$Be, $^{19}$C and $^{31}$Ne one-neutron halo nuclei. It is very sensitive to the neutron separation energy.

  18. Beta delayed emission of a proton by a one-neutron halo nucleus

    E-Print Network [OSTI]

    Baye, D

    2010-01-01T23:59:59.000Z

    Some one-neutron halo nuclei can emit a proton in a beta decay of the halo neutron. The branching ratio towards this rare decay mode is calculated within a two-body potential model of the initial core+neutron bound state and final core+proton scattering states. The decay probability per second is evaluated for the $^{11}$Be, $^{19}$C and $^{31}$Ne one-neutron halo nuclei. It is very sensitive to the neutron separation energy.

  19. Merging Rate of Dark Matter Halos: Evolution and Dependence on Environment

    E-Print Network [OSTI]

    Stefan Gottloeber; Anatoly Klypin; Andrey V. Kravtsov

    1999-09-01T23:59:59.000Z

    We discuss the impact of the cosmological environment on the evolution of dark matter halos using a high-resolution simulation within a spatially flat LCDM cosmology.

  20. Abstract--This paper deals with halogen luminaries, ones of the main used lighting sources in residential area. The use of these

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    power systems were performed to show the accuracy of developed models. Index Terms--halogen lamp, EMTP is with Schneider Electric Industries (Business Unit Power ­ Systems and Mechatronic Integration), 31 Pierre Mendes and the LV power systems. But studies regarding the power up problem of electrical lighting systems where ETs

  1. Spectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya,* Ilya U. Goldschleger, V. Ara Apkarian, and Kenneth C. Janda

    E-Print Network [OSTI]

    Apkarian, V. Ara

    , the earliest gas clathrate hydrate discovered, was first prepared by Davy in 1811;1 bromine hydrateSpectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya report the first UV-vis spectroscopic study of bromine molecules confined in clathrate hydrate cages

  2. Core excitation effects in the breakup of halo nuclei

    SciTech Connect (OSTI)

    Moro, A. M.; Diego, R. de; Lay, J. A.; Crespo, R.; Johnson, R. C.; Arias, J. M.; Gomez-Camacho, J. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal) and Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Prof. Cavaco Silva, Taguspark (Portugal); Physics Department, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain) and Centro Nacional de Aceleradores, Universidad de Sevilla/Junta de Andalucia, E-41092 Sevilla (Spain)

    2012-10-20T23:59:59.000Z

    The role of core excitation in the structure and dynamics of two-body halo nuclei is investigated. We present calculations for the resonant breakup of {sup 11}Be on protons at an incident energy of 63.7 MeV/nucleon, where core excitation effects were shown to be important. To describe the reaction, we use a recently developed extension of the DWBA formalism which incorporates these core excitation effects within the no-recoil approximation. The validity of the no-recoil approximation is also examined by comparing with DWBA calculations which take into account core recoil. In addition, calculations with two different continuum representations are presented and compared.

  3. Impacts of halogen additions on mercury oxidation, in a slipstream selective catalyst reduction (SCR), reactor when burning sub-bituminous coal

    SciTech Connect (OSTI)

    Yan Cao; Zhengyang Gao; Jiashun Zhu; Quanhai Wang; Yaji Huang; Chengchung Chiu; Bruce Parker; Paul Chu; Wei-ping Pan [Western Kentucky University (WKU), Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology (ICSET)

    2008-01-01T23:59:59.000Z

    This paper presents a comparison of impacts of halogen species on the elemental mercury (Hg(0)) oxidation in a real coal-derived flue gas atmosphere. It is reported there is a higher percentage of Hg(0) in the flue gas when burning sub-bituminous coal (herein Powder River Basin (PRB) coal) and lignite, even with the use of selective catalytic reduction (SCR). The higher Hg(0) concentration in the flue gas makes it difficult to use the wet-FGD process for the mercury emission control in coal-fired utility boilers. Investigation of enhanced Hg(0) oxidation by addition of hydrogen halogens (HF, HCl, HBr, and HI) was conducted in a slipstream reactor with and without SCR catalysts when burning PRB coal. Two commercial SCR catalysts were evaluated. SCR catalyst no. 1 showed higher efficiencies of both NO reduction and Hg(0) oxidation than those of SCR catalyst no. 2. NH{sub 3} addition seemed to inhibit the Hg(0) oxidation, which indicated competitive processes between NH{sub 3} reduction and Hg(0) oxidation on the surface of SCR catalysts. The hydrogen halogens, in the order of impact on Hg(0) oxidation, were HBr, HI, and HCl or HF. Addition of HBr at approximately 3 ppm could achieve 80% Hg(0) oxidation. Addition of HI at approximately 5 ppm could achieve 40% Hg(0) oxidation. In comparison to the empty reactor, 40% Hg(0) oxidation could be achieved when HCl addition was up to 300 ppm. The enhanced Hg(0) oxidation by addition of HBr and HI seemed not to be correlated to the catalytic effects by both evaluated SCR catalysts. The effectiveness of conversion of hydrogen halogens to halogen molecules or interhalogens seemed to be attributed to their impacts on Hg(0) oxidation. 30 refs., 4 figs.

  4. The 3D Geometry of Dark Matter Halos

    E-Print Network [OSTI]

    J. -F. Becquaert; F. Combes

    1997-04-10T23:59:59.000Z

    The thickness of the neutral hydrogen layer, coupled with the rotation curve, traces the outer dark matter potential. We estimate the amplitude of the flaring in spiral galaxies from a 3D model of the HI gas. Warps in particular are explicitly parametrized in the form of an harmonical density wave. Applying our method to the galaxy NGC 891, the only model that could fit the observations, and in particular the HI at large height above the plane, includes a strong warp with a line of node almost coinciding with the line of sight. This high-Z HI is not observed at the most extreme velocity channels, those corresponding to high rotational velocities. This is accounted for by the model, since orbits in the tilted planes are not circular, but elongated, with their minor axis in the galaxy plane. Their velocity on the major axis (i.e. at their maximal height above the plane) is then 30% less than in the plane. We finally connect the modelled vertical outer gaseous distribution to the dark matter through hydrodynamical and gravitational equations. Under the assumption of isotropy of the gaseous velocity dispersion, we conclude on a very flattened halo geometry for the galaxy NGC 891 ($q \\approx 0.2$), while a vertical velocity dispersion smaller that the radial one would lead to a less flattened Dark Matter Halo ($q \\approx 0.4-0.5$). Both results however suggests that dark matter is dissipative or has been strongly influenced by the gas dynamics.

  5. Signatures of Dark Matter Halo Expansion in Galaxy Populations

    E-Print Network [OSTI]

    Brook, Chris B

    2015-01-01T23:59:59.000Z

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

  6. Modeling Tidal Streams in evolving dark matter halos

    E-Print Network [OSTI]

    Jorge Penarrubia; Andrew J. Benson; David Martinez-Delgado; Hans-Walter Rix

    2005-12-20T23:59:59.000Z

    We explore whether stellar tidal streams can provide information on the secular, cosmological evolution of the Milky Way's gravitational potential and on the presence of subhalos. We carry out long-term (~t_hubble) N-body simulations of disrupting satellite galaxies in a semi-analytic Galaxy potential where the dark matter halo and the subhalos evolve according to a LCDM cosmogony. All simulations are constrained to end up with the same position and velocity at present. Our simulations account for: (i) the secular evolution of the host halo's mass, size and shape, (ii) the presence of subhalos and (iii) dynamical friction. We find that tidal stream particles respond adiabatically to the Galaxy growth so that, at present, the energy and angular momentum distribution is exclusively determined by the present Galaxy potential. In other words, all present-day observables can only constrain the present mass distribution of the Galaxy independent of its past evolution. We also show that, if the full phase-space distribution of a tidal stream is available, we can accurately determine (i) the present Galaxy's shape and (ii) the amount of mass loss from the stream's progenitor, even if this evolution spanned a cosmologically significant epoch.

  7. IMPROVED MODELING OF THE MASS DISTRIBUTION OF DISK GALAXIES BY THE EINASTO HALO MODEL

    SciTech Connect (OSTI)

    Chemin, Laurent [Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, BP 89, 33271 Floirac Cedex (France); De Blok, W. J. G. [ACGC, Department of Astronomy, University of Cape Town, Rondebosch 7700 (South Africa); Mamon, Gary A., E-mail: chemin@obs.u-bordeaux1.fr, E-mail: edeblok@ast.uct.ac.za, E-mail: gam@iap.fr [Institut d'Astrophysique de Paris (UMR 7095: CNRS and UPMC), 98 bis Bd. Arago, 75014 Paris (France)

    2011-10-15T23:59:59.000Z

    Analysis of the rotation curves (RCs) of spiral galaxies provides an efficient diagnostic for studying the properties of dark matter halos and their relations with baryonic material. Since the cored pseudo-isothermal (Iso) model usually provides a better description of observed RCs than does the cuspy Navarro-Frenk-White (NFW) model, there have been concerns that the {Lambda}CDM primordial density fluctuation spectrum may not be the correct one. We have modeled the RCs of galaxies from The H I Nearby Galaxy Survey (THINGS) with the Einasto halo model, which has emerged as the best-fitting model of the halos arising in dissipationless cosmological N-body simulations. We find that the RCs are significantly better fit with the Einasto halo than with either Iso or NFW halo models. In our best-fit Einasto models, the radius of density slope -2 and the density at this radius are highly correlated. The Einasto index, which controls the overall shape of the density profile, is near unity on average for intermediate and low mass halos. This is not in agreement with the predictions from {Lambda}CDM simulations. The indices of the most massive halos are in rough agreement with those cosmological simulations and appear correlated with the halo virial mass. We find that a typical Einasto density profile declines more strongly in its outermost parts than any of the Iso or NFW models whereas it is relatively shallow in its innermost regions. The core nature of those regions of halos thus extends the cusp-core controversy found for the NFW model with low surface density galaxies to the Einasto halo with more massive galaxies like those of THINGS. The Einasto concentrations decrease as a function of halo mass, in agreement with trends seen in numerical simulations. However, they are generally smaller than values expected for simulated Einasto halos. We thus find that, so far, the Einasto halo model provides the best match to the observed RCs and can therefore be considered as a new standard model for dark matter halos.

  8. $^6$He nucleus in halo effective field theory

    E-Print Network [OSTI]

    C. Ji; Ch. Elster; D. R. Phillips

    2014-11-03T23:59:59.000Z

    Background: In recent years properties of light rare isotopes have been measured with high accuracy. At the same time, the theoretical description of light nuclei has made enormous progress, and properties of, e.g., the Helium isotopes can now be calculated {\\it ab initio}. These advances make those rare isotopes an ideal testing ground for effective field theories (EFTs) built upon cluster degrees of freedom. Purpose: Systems with widely separated intrinsic scales are well suited to an EFT treatment. The Borromean halo nucleus $^6$He exhibits such a separation of scales. In this work an EFT in which the degrees of freedom are the valence neutrons ($n$) and an inert $^4$He-core ($\\alpha$) is employed. The properties of ${}^6$He can then be calculated using the momentum-space Faddeev equations for the $\\alpha nn$ bound state to obtain information on ${}^6$He at leading order (LO) within the EFT. Results: The $nn$ virtual state and the $^2$P$_{3/2}$ resonance in $^5$He give the two-body amplitudes which are input to our LO three-body Halo EFT calculation. We find that without a genuine three-body interaction the two-neutron separation energy $S_{2n}$ of ${}^6$He is strongly cutoff dependent. We introduce a $nn \\alpha$ "three-body" operator which renormalizes the system, adjusting its coefficient to reproduce the $S_{2n}$ of $^6$He. The Faddeev components are then cutoff independent for cutoffs of the order of, and above, the breakdown scale of the Halo EFT. Conclusions: As in the case of a three-body system where only resonant s-wave interactions are present, one three-body input is required for the renormalization of the EFT equations that describe $^6$He at LO. However, in contrast to the s-wave-only case, the running of the LO $nn\\alpha$ counterterm does not exhibit discrete scale invariance, due to the presence of the p-wave $n\\alpha$ interaction.

  9. Comparing Light Bulbs

    Broader source: Energy.gov [DOE]

    In this exercise, students will use a light to demonstrate the difference between being energy-efficient and energy-wasteful, and learn what energy efficiency means.

  10. Antibound States and Halo Formation in the Gamow Shell Model

    E-Print Network [OSTI]

    N. Michel; W. Nazarewicz; M. Ploszajczak; J. Rotureau

    2006-09-07T23:59:59.000Z

    The open quantum system formulation of the nuclear shell model, the so-called Gamow Shell Model (GSM), is a multi-configurational SM that employs a single-particle basis given by the Berggren ensemble consisting of Gamow states and the non-resonant continuum of scattering states. The GSM is of particular importance for weakly bound/unbound nuclear states where both many-body correlations and the coupling to decay channels are essential. In this context, we investigate the role of l=0 antibound (virtual) neutron single-particle states in the shell model description of loosely bound wave functions, such as the ground state wave function of a halo nucleus 11Li.

  11. Decaying Neutrinos and the Flattening of the Galactic Halo

    E-Print Network [OSTI]

    D. W. Sciama

    1997-04-10T23:59:59.000Z

    The recently constructed Dehnen-Binney set of mass models for the Galaxy is used to show that the decaying neutrino theory for the ionisation of the interstellar medium (Sciama 1990a, 1993) requires the neutrino halo of the Galaxy to be as flattened as is observationally permitted (axial ratio q=0.2 or shape E8). The argument involves an evaluation of the contribution of red-shifted decay photons from the cosmological distribution of neutrinos to the extragalactic diffuse background at 1500 Angstroms. This contribution must be as large as is observationally permitted. These two requirements depend on the decay lifetime in potentially conflicting ways. For consistency to be achieved the lifetime must lie within 30 per cent of 10^23 seconds.

  12. Spectral Energy Distributions for Disk and Halo M--Dwarfs

    E-Print Network [OSTI]

    S. K. Leggett; F. Allard; Conard Dahn; P. H. Hauschildt; T. H. Kerr; J. Rayner

    2000-01-07T23:59:59.000Z

    We have obtained infrared (1 to 2.5 micron) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric parameters metallicity, effective temperature and radius are determined for the sample. We find good agreement between observation and theory except for known problems due to incomplete molecular data for metal hydrides and water. The metal-poor M subdwarfs are well matched by the models as oxide opacity sources are less important in this case. The derived effective temperatures for the sample range from 3600K to 2600K; at these temperatures grain formation and extinction are not significant in the photosphere. The derived metallicities range from solar to one-tenth solar. The radii and effective temperatures derived agree well with recent models of low mass stars.

  13. Space Weather Application Using Projected Velocity Asymmetry of Halo CMEs

    E-Print Network [OSTI]

    G. Michalek; N. Gopalswamy; S. Yashiro

    2008-01-13T23:59:59.000Z

    Halo coronal mass ejections (HCMEs) originating from regions close to the center of the Sun are likely to be responsible for severe geomagnetic storms. It is important to predict geo-effectiveness of HCMEs using observations when they are still near the Sun. Unfortunately, coronagraphic observations do not provide true speeds of CMEs due to the projection effects. In the present paper, we present a new technique allowing estimate the space speed and approximate source location using projected speeds measured at different position angles for a given HCME (velocity asymmetry). We apply this technique to HCMEs observed during 2001-2002 and find that the improved speeds are better correlated with the travel times of HCMEs to Earth and with the magnitudes ensuing geomagnetic storms.

  14. Internal Alignments of Red Versus Blue Discs in Dark Matter Halos

    E-Print Network [OSTI]

    Debattista, Victor P; Roskar, Rok; Quinn, Thomas; Moore, Ben; Cole, David R

    2015-01-01T23:59:59.000Z

    Large surveys have shown that red galaxies are preferentially aligned with their halos while blue galaxies have a more isotropic distribution. Since halos generally align with their filaments this introduces a bias in the measurement of the cosmic shear from weak lensing. It is therefore vitally important to understand why this difference arises. We explore the stability of different disc orientations within triaxial halos. We show that, in the absence of gas, the disc orientation is most stable when its spin is along the minor axis of the halo. Instead when gas cools onto a disc it is able to form in almost arbitrary orientation, including off the main planes of the halo (but avoiding an orientation perpendicular to the halo's intermediate axis). Substructure helps gasless galaxies reach alignment with the halo faster, but have less effect on galaxies when gas is cooling onto the disc. Our results provide a novel and natural interpretation for why red, gas poor galaxies are preferentially aligned with their ...

  15. The Flattened Dark Matter Halo of M31 as Deduced from the Observed HI Scale Heights

    E-Print Network [OSTI]

    Arunima Banerjee; Chanda J. Jog

    2008-06-23T23:59:59.000Z

    In this paper, we use the outer-galactic HI scale height data as well as the observed rotation curve as constraints to determine the halo density distribution of the Andromeda galaxy (M31). We model the galaxy as a gravitationally-coupled system of stars and gas, responding to the external force-field of a known Hernquist bulge and the dark matter halo, the density profile of the latter being characterized by four free parameters. The parameter space of the halo is optimized so as to match the observed HI thickness distribution as well as the rotation curve on an equal footing, unlike the previous studies of M31 which were based on rotation curves alone. We show that an oblate halo, with an isothermal density profile, provides the best fit to the observed data. This gives a central density of 0.011 M_sun /pc^3, a core radius of 21 kpc, and an axis ratio of 0.4. The main result from this work is the flattened dark matter halo for M31, which is required to match the outer galactic HI scale height data. Interestingly, such flattened halos lie at the most oblate end of the distribution of halo shapes found in recent cosmological simulations.

  16. A Two-Parameter Matching Scheme for Massive Galaxies and Dark Matter Haloes

    E-Print Network [OSTI]

    Kulier, Andrea

    2015-01-01T23:59:59.000Z

    Halo Abundance Matching has been used to construct a one-parameter mapping between galaxies and dark matter haloes by assuming that halo mass and galaxy luminosity (or stellar mass) are monotonically related. While this approach has been reasonably successful, it is known that galaxies must be described by at least two parameters, as can be seen from the two-parameter Fundamental Plane on which massive early-type galaxies lie. In this paper, we derive a connection between initial dark matter density perturbations in the early universe and present-day virialized dark matter haloes by assuming simple spherical collapse combined with conservation of mass and energy. We find that $z = 0$ halo concentration, or alternatively the inner slope of the halo density profile $\\alpha$, is monotonically and positively correlated with the collapse redshift of the halo. This is qualitatively similar to the findings of some previous works based on numerical simulations, with which we compare our results. We then describe how ...

  17. Discovery, SAR, and Radiolabeling of Halogenated Benzimidazole Carboxamide Antagonists as Useful Tools for (alpha)4(beta)1 Integrin Expressed on T- and B-cell Lymphomas

    SciTech Connect (OSTI)

    Carpenter, R D; Natarajan, A; Lau, E Y; Andrei, M; Solano, D M; Lightstone, F C; DeNardo, S J; Lam, K S; Kurth, M J

    2010-02-08T23:59:59.000Z

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin is an attractive yet poorly understood target for selective diagnosis and treatment of T- and B-cell lymphomas. This report focuses on the rapid microwave preparation of medicinally pertinent benzimidazole heterocycles, structure-activity relationships (SAR) of novel halobenzimidazole carboxamide antagonists 3-6, and preliminary biological evaluation of radioiodinated agents 7, 8, and 18. The I-125 derivative 18 had good tumor uptake (12 {+-} 1% ID/g at 24 h; 4.5 {+-} 1% ID/g at 48 h) and tumor:kidney ratio ({approx}4:1 at 24 h; 2.5:1 at 48 h) in xenograft murine models of B-cell lymphoma. Molecular homology models of {alpha}{sub 4}{beta}{sub 1} integrin have predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. These high affinity ({approx} pM binding) halogenated ligands are attractive tools for medicinal and biological use; the fluoro and iodo derivatives are potential radiodiagnostic ({sup 18}F) or radiotherapeutic ({sup 131}I) agents, whereas the chloro and bromo analogues could provide structural insight into integrin-ligand interactions through photoaffinity cross-linking/mass spectroscopy experiments, as well as co-crystallization X-ray studies.

  18. Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario

    E-Print Network [OSTI]

    Ishimaru, Yuhri; Prantzos, Nikos

    2015-01-01T23:59:59.000Z

    Binary mergers (NSMs) of double neutron star (and black hole-neutron star) systems are suggested to be major sites of r-process elements in the Galaxy by recent hydrodynamical and nucleosynthesis studies. It has been pointed out, however, that the estimated long lifetimes of neutron star binaries are in conflict with the presence of r-process-enhanced halo stars at metallicities as low as [Fe/H] ~ -3. To resolve this problem, we examine the role of NSMs in the early Galactic chemical evolution on the assumption that the Galactic halo was formed from merging sub-halos. We present simple models for the chemical evolution of sub-halos with total final stellar masses between 10^4 M_solar and 2 x 10^8 M_solar. Typical lifetimes of compact binaries are assumed to be 100 Myr (for 95% of their population) and 1 Myr (for 5%), according to recent binary population synthesis studies. The resulting metallcities of sub-halos and their ensemble are consistent with the observed mass-metallicity relation of dwarf galaxies in...

  19. Observations and Modeling of the Disk-Halo Interaction in our Galaxy

    E-Print Network [OSTI]

    Magdalen Normandeau; Shantanu Basu

    1998-11-15T23:59:59.000Z

    Galaxies are surrounded by large halos of hot gas which must be replenished as the gas cools. This led Norman & Ikeuchi (1989) to propose the chimney model of the interstellar medium, which predicts that there should be on the order of a thousand such conduits connecting the disk and the halo of a galaxy. Where then are these structures and other possible disk-halo connections in our galaxy? What do they look like, how can we detect them, and what do they tell us about the interstellar medium and about the Galaxy? We present a review of the observational evidence for Galactic disk-halo connections, beginning with large scale searches and then concentrating on the characteristics of selected candidates. We summarize how modeling these structures can provide information on the structure of the interstellar medium in which they evolved, focusing on the W4 superbubble and the Anchor as illustrations.

  20. Possible features of galactic halo with electric field and observational constraints

    E-Print Network [OSTI]

    Koushik Chakraborty; Farook Rahaman; Saibal Ray; Arka Nandi; Nasarul Islam

    2014-12-15T23:59:59.000Z

    Observed rotational curves of neutral hydrogen clouds strongly support the fact that galactic halo contains huge amount of nonluminous matter, the so called gravitational dark matter. The nature of dark matter is a point of debate among the researchers. Recent observations reported the presence of ions of O, S, C, Si etc in the galactic halo and intergalactic medium. This supports the possibility of existence of electric field in the galactic halo region. We therefore propose a model of galactic halo considering this electric field arising due to charged particles as one of the inputs for the background spacetime metric. Considering dark matter as an anisotropic fluid we obtain the expressions for energy density and pressure of dark matter there and consequently the equation of state of dark matter. Various other aspects of the solutions are also analyzed along with a critical comparison with and constraints of different observational evidences.

  1. Chandra Observations of ULIRGs: Extended Hot Gas Halos in Merging Galaxies

    E-Print Network [OSTI]

    Z. Y. Huo; X. Y. Xia; S. J. Xue; S. Mao; Z. G. Deng

    2004-05-09T23:59:59.000Z

    We study the properties of hot gaseous halos in 10 nearby ultraluminous IRAS galaxies observed with the ACIS instrument on board Chandra. For all sample galaxies, diffuse soft X-ray emissions are found within ~10 kpc of the central region; their spectra are well fitted by a MEKAL model plus emission lines from alpha-elements and other ions. The temperature of the hot gas is about 0.7 keV and metallicity is about 1 solar. Outside the central region, extended hot gaseous halos are found for nine out of the ten ULIRGs. Most spectra of these extended halos can be fitted with a MEKAL model with a temperature of about 0.6 keV and a low metallicity (~ 0.1 solar). We discuss the implications of our results on the origin of X-ray halos in elliptical galaxies and the feedback processes associated with starbursts.

  2. INVESTIGATION OF HALO FORMATION IN CONTINUOUS BEAMS USING WEIGHTED POLYNOMIAL EXPANSIONS AND PERTURBATIONAL ANALYSIS

    SciTech Connect (OSTI)

    C. ALLEN

    2000-08-01T23:59:59.000Z

    We consider halo formation in continuous beams oscillating at natural modes by inspecting particle trajectories. Trajectory equations containing field nonlinearities are derived from a weighted polynomial expansion. We then use perturbational techniques to further analyze particle motion.

  3. Limits on Hot Galactic Halo Gas from X-ray Absorption Lines

    E-Print Network [OSTI]

    Yao, Yangsen

    Although the existence of large-scale hot gaseous halos around massive disk galaxies has been theorized for a long time, there is yet very little observational evidence. We report the Chandra and XMM-Newton grating spectral ...

  4. Halo-Independent analysis of direct dark matter detection data for any WIMP interaction

    E-Print Network [OSTI]

    Graciela B. Gelmini

    2014-11-04T23:59:59.000Z

    The halo independent comparison of direct dark matter detection data eliminates the need to make any assumption on the uncertain local dark matter distribution and is complementary to the usual data comparison which required assuming a dark halo model for our galaxy. The method, initially proposed for WIMPs with spin-independent contact interactions, has been generalized to any other interaction and applied to recent data on "Light WIMPs".

  5. GLOBAL PROPERTIES OF M31'S STELLAR HALO FROM THE SPLASH SURVEY. I. SURFACE BRIGHTNESS PROFILE

    SciTech Connect (OSTI)

    Gilbert, Karoline M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Guhathakurta, Puragra [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Beaton, Rachael L.; Majewski, Steven R.; Ostheimer, James C.; Patterson, Richard J. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Bullock, James; Tollerud, Erik J. [Center for Cosmology, Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697 (United States); Geha, Marla C. [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Kalirai, Jason S. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Kirby, Evan N. [California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Tanaka, Mikito; Chiba, Masashi, E-mail: kgilbert@astro.washington.edu [Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan)

    2012-11-20T23:59:59.000Z

    We present the surface brightness profile of M31's stellar halo out to a projected radius of 175 kpc. The surface brightness estimates are based on confirmed samples of M31 red giant branch stars derived from Keck/DEIMOS spectroscopic observations. A set of empirical spectroscopic and photometric M31 membership diagnostics is used to identify and reject foreground and background contaminants. This enables us to trace the stellar halo of M31 to larger projected distances and fainter surface brightnesses than previous photometric studies. The surface brightness profile of M31's halo follows a power law with index -2.2 {+-} 0.2 and extends to a projected distance of at least {approx}175 kpc ({approx}2/3 of M31's virial radius), with no evidence of a downward break at large radii. The best-fit elliptical isophotes have b/a = 0.94 with the major axis of the halo aligned along the minor axis of M31's disk, consistent with a prolate halo, although the data are also consistent with M31's halo having spherical symmetry. The fact that tidal debris features are kinematically cold is used to identify substructure in the spectroscopic fields out to projected radii of 90 kpc and investigate the effect of this substructure on the surface brightness profile. The scatter in the surface brightness profile is reduced when kinematically identified tidal debris features in M31 are statistically subtracted; the remaining profile indicates that a comparatively diffuse stellar component to M31's stellar halo exists to large distances. Beyond 90 kpc, kinematically cold tidal debris features cannot be identified due to small number statistics; nevertheless, the significant field-to-field variation in surface brightness beyond 90 kpc suggests that the outermost region of M31's halo is also comprised to a significant degree of stars stripped from accreted objects.

  6. The Peculiar Behavior of Halo Coronal Mass Ejections in Solar Cycle 24

    E-Print Network [OSTI]

    Gopalswamy, N; Akiyama, S; Mäkelä, P; Yashiro, S; Michalek, G

    2015-01-01T23:59:59.000Z

    We report on a remarkable finding that the halo coronal mass ejections (CMEs) in cycle 24 are more abundant than in cycle 23, although the sunspot number in cycle 24 has dropped by about 40%. We also find that the distribution of halo-CME source locations is different in cycle 24: the longitude distribution of halos is much flatter with the number of halos originating at central meridian distance >/=60 degrees twice as large as that in cycle 23. On the other hand, the average speed and the associated soft X-ray flare size are the same in the two cycles, suggesting that the ambient medium into which the CMEs are ejected is significantly different. We suggest that both the higher abundance and larger central meridian longitudes of halo CMEs can be explained as a consequence of the diminished total pressure in the heliosphere in cycle 24 (Gopalswamy et al. 2014). The reduced total pressure allows CMEs expand more than usual making them appear as halos.

  7. THE ROCKSTAR PHASE-SPACE TEMPORAL HALO FINDER AND THE VELOCITY OFFSETS OF CLUSTER CORES

    SciTech Connect (OSTI)

    Behroozi, Peter S.; Wechsler, Risa H.; Wu, Hao-Yi [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)] [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2013-01-10T23:59:59.000Z

    We present a new algorithm for identifying dark matter halos, substructure, and tidal features. The approach is based on adaptive hierarchical refinement of friends-of-friends groups in six phase-space dimensions and one time dimension, which allows for robust (grid-independent, shape-independent, and noise-resilient) tracking of substructure; as such, it is named ROCKSTAR (Robust Overdensity Calculation using K-Space Topologically Adaptive Refinement). Our method is massively parallel (up to 10{sup 5} CPUs) and runs on the largest current simulations (>10{sup 10} particles) with high efficiency (10 CPU hours and 60 gigabytes of memory required per billion particles analyzed). A previous paper has shown ROCKSTAR to have excellent recovery of halo properties; we expand on these comparisons with more tests and higher-resolution simulations. We show a significant improvement in substructure recovery compared to several other halo finders and discuss the theoretical and practical limits of simulations in this regard. Finally, we present results that demonstrate conclusively that dark matter halo cores are not at rest relative to the halo bulk or substructure average velocities and have coherent velocity offsets across a wide range of halo masses and redshifts. For massive clusters, these offsets can be up to 350 km s{sup -1} at z = 0 and even higher at high redshifts. Our implementation is publicly available at http://code.google.com/p/rockstar.

  8. BROKEN AND UNBROKEN: THE MILKY WAY AND M31 STELLAR HALOS

    SciTech Connect (OSTI)

    Deason, A. J. [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Belokurov, V.; Evans, N. W. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom)] [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Johnston, K. V., E-mail: alis@ucolick.org [Department of Astronomy, Columbia University, New York, NY 10027 (United States)

    2013-02-15T23:59:59.000Z

    We use the Bullock and Johnston suite of simulations to study the density profiles of L*-type galaxy stellar halos. Observations of the Milky Way and M31 stellar halos show contrasting results: the Milky Way has a 'broken' profile, where the density falls off more rapidly beyond {approx}25 kpc, while M31 has a smooth profile out to 100 kpc with no obvious break. Simulated stellar halos, built solely by the accretion of dwarf galaxies, also exhibit this behavior: some halos have breaks, while others do not. The presence or absence of a break in the stellar halo profile can be related to the accretion history of the galaxy. We find that a break radius is strongly related to the buildup of stars at apocenters. We relate these findings to observations, and find that the 'break' in the Milky Way density profile is likely associated with a relatively early ({approx}6-9 Gyr ago) and massive accretion event. In contrast, the absence of a break in the M31 stellar halo profile suggests that its accreted satellites have a wide range of apocenters. Hence, it is likely that M31 has had a much more prolonged accretion history than the Milky Way.

  9. Linking the Metallicity Distribution of Galactic Halo Stars to the Enrichment History of the Universe

    E-Print Network [OSTI]

    Evan Scannapieco; Tom Broadhurst

    2001-02-06T23:59:59.000Z

    We compare the metallicity distribution of Galactic Halo stars with 3D realizations of hierarchical galaxy formation. Outflows from dwarf galaxies enrich the intergalactic medium inhomogeneously, at a rate depending on the local galaxy density. Consequently, the first stars created in small early-forming galaxies are less metal-rich that the first stars formed in more massive galaxies which typically form later. As most halo stars are likely to originate in accreted dwarfs, while disk stars formed out of outflow-enriched gas, this scenario naturally generates a ``metallicity floor'' for old disk stars, which we find to be roughly coincident with the higher end of our predicted metallicity distribution of halo stars, in agreement with observations. The broad and centrally peaked distribution of halo star metallicities is well reproduced in our models, with a natural dispersion depending on the exact accretion history. Our modeling includes the important ``baryonic stripping'' effect of early outflows, which brush away the tenuously held gas in neighboring pre-virialized density perturbations. This stripping process does not significantly modify the predicted shape of the halo star metal distribution but inhibits star-formation and hence the number of accreted stars, helping to reproduce the observed total Galactic halo luminosity and also the lack of low-luminosity local dwarf galaxies relative to N-body predictions.

  10. The Dependence of the Mass Assembly History of Cold Dark Matter Halos on Environment

    E-Print Network [OSTI]

    C. Maulbetsch; V. Avila-Reese; P. Colin; S. Gottloeber; A. Khalatyan; M. Steinmetz

    2006-09-23T23:59:59.000Z

    We show by means of a high-resolution N-body simulation how the mass assembly histories of galaxy-size cold dark matter (CDM) halos depend on environment. Halos in high density environments form earlier and a higher fraction of their mass is assembled in major mergers, compared to low density environments. The distribution of the present-day specific mass aggregation rate is strongly dependent on environment. While in low density environments only ~20% of the halos are not accreting mass at the present epoch, this fraction rises to ~80% at high densities. At z=1 the median of the specific aggregation rate is ~4 times larger than at z=0 and almost independent on environment. All the dependences on environment found here are critically enhanced by local processes associated to subhalos because the fraction of subhalos increases as the environment gets denser. The distribution of the halo specific mass aggregation rate as well as its dependence on environment resemble the relations for the specific star formation rate distribution of galaxies. An analogue of the morphology-density relation is also present at the level of CDM halos, being driven by the halo major merging history. Nevertheless, baryonic processes are necessary in order to explain further details and the evolution of the star formation rate-, color- and morphology-environment relations.

  11. An excursion set model of the cosmic web: The abundance of sheets, filaments and halos

    E-Print Network [OSTI]

    Jiajian Shen; Tom Abel; H. J. Mo; Ravi Sheth

    2006-03-27T23:59:59.000Z

    We discuss an analytic approach for modeling structure formation in sheets, filaments and knots. This is accomplished by combining models of triaxial collapse with the excursion set approach: sheets are defined as objects which have collapsed along only one axis, filaments have collapsed along two axes, and halos are objects in which triaxial collapse is complete. In the simplest version of this approach, which we develop here, large scale structure shows a clear hierarchy of morphologies: the mass in large-scale sheets is partitioned up among lower mass filaments, which themselves are made-up of still lower mass halos. Our approach provides analytic estimates of the mass fraction in sheets, filaments and halos, and its evolution, for any background cosmological model and any initial fluctuation spectrum. In the currently popular $\\Lambda$CDM model, our analysis suggests that more than 99% of the cosmic mass is in sheets, and 72% in filaments, with mass larger than $10^{10} M_{\\odot}$ at the present time. For halos, this number is only 46%. Our approach also provides analytic estimates of how halo abundances at any given time correlate with the morphology of the surrounding large-scale structure, and how halo evolution correlates with the morphology of large scale structure.

  12. KAT-7 detection of radio halo emission in the Triangulum Australis galaxy cluster

    E-Print Network [OSTI]

    Scaife, Anna M M; de Gasperin, Francesco; Brueggen, Marcus; Tasse, Cyril; Magnus, Lindsay

    2015-01-01T23:59:59.000Z

    We report the presence of high significance diffuse radio emission from the Triangulum Australis cluster using observations made with the KAT-7 telescope and propose that this emission is a giant radio halo. We compare the radio power from this proposed halo with X-ray and SZ measurements and demonstrate that it is consistent with the established scaling relations for cluster haloes. By combining the X-ray and SZ data we calculate the ratio of non-thermal to thermal electron pressure within Triangulum Australis to be $X=0.658\\pm0.054$. We use this ratio to constrain the maximum magnetic field strength within the halo region to be $B_{\\rm max, halo} = 33.08\\,\\mu$G and compare this with the minimum field strength from equipartition of $B_{\\rm min, halo} = 0.77(1+k)^{2/7}\\,\\mu$G to place limits on the range of allowed magnetic field strength within this cluster. We compare these values to those for more well-studied systems and discuss these results in the context of equipartition of non-thermal energy densities...

  13. Gamma Rays from Superheavy Relic Particles in the Halo

    E-Print Network [OSTI]

    Pasquale Blasi

    1999-05-15T23:59:59.000Z

    Superheavy (SH) quasistable particles generated in the Early Universe could be responsable for Ultra High Energy Cosmic Rays (UHECR) and be a component of Cold Dark Matter (CDM) in the universe. These particles are likely to cluster in the galactic halo, so that the main part of UHECR are gamma rays produced in the decay of neutral pions. Charged pions are also produced in the same process and result in high energy electrons. We consider here the production of gamma rays by synchrotron emission of these electrons in the galactic magnetic field. The gamma ray fluxes are in the region of interest for some current and proposed experiments (e.g. EGRET, GLAST, MILAGRO) in the energy range $0.1-10^4$ GeV. A comparison with the existing upper limits at $10^5-10^8$ GeV is also carried out. The detection of this flux of gamma rays would be an important signature of SH relic particles as sources of UHECR and would give a clue to the physics of the Early Universe.

  14. Electric properties of the Beryllium-11 system in Halo EFT

    E-Print Network [OSTI]

    H. -W. Hammer; D. R. Phillips

    2012-08-15T23:59:59.000Z

    We compute E1 transitions and electric radii in the Beryllium-11 nucleus using an effective field theory that exploits the separation of scales in this halo system. We fix the leading-order parameters of the EFT from measured data on the 1/2+ and 1/2- levels in Be-11 and the B(E1) strength for the transition between them. We then obtain predictions for the B(E1) strength for Coulomb dissociation of the Be-11 nucleus to the continuum. We also compute the charge radii of the 1/2+ and 1/2- states. Agreement with experiment within the expected accuracy of a leading-order computation in this EFT is obtained. We also discuss how next-to-leading-order (NLO) corrections involving both s-wave and p-wave neutron-Be-10 interactions affect our results, and display the NLO predictions for quantities which are free of additional short-distance operators at this order. Information on neutron-Be-10 scattering in the relevant channels is inferred.

  15. Testing gravity with halo density profiles observed through gravitational lensing

    SciTech Connect (OSTI)

    Narikawa, Tatsuya; Yamamoto, Kazuhiro, E-mail: narikawa@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

    2012-05-01T23:59:59.000Z

    We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the Vainshtein mechanism to recover Newtonian gravity in high-density regions, however it might not be completely hidden on the outer side of a cluster of galaxies. Then the modified gravity might yield an observational signature in a surface mass density of a cluster of galaxies measured through gravitational lensing, since the scalar field could contribute to the lensing potential. We investigate how the transition in the Vainshtein mechanism affects the surface mass density observed through gravitational lensing, assuming that the density profile of a cluster of galaxies follows the original Navarro-Frenk-White (NFW) profile, the generalized NFW profile and the Einasto profile. We compare the theoretical predictions with observational results of the surface mass density reported recently by other researchers. We obtain constraints on the amplitude and the typical scale of the transition in the Vainshtein mechanism in a subclass of the generalized galileon model.

  16. An Asymmetric Cone Model for Halo Coronal Mass Ejections

    E-Print Network [OSTI]

    G. Michalek

    2007-10-24T23:59:59.000Z

    Due to projection effects, coronagraphic observations cannot uniquely determine parameters relevant to the geoeffectiveness of CMEs, such as the true propagation speed, width, or source location. The Cone Model for Coronal Mass Ejections (CMEs) has been studied in this respect and it could be used to obtain these parameters. There are evidences that some CMEs initiate from a flux-rope topology. It seems that these CMEs should be elongated along the flux-rope axis and the cross section of the cone base should be rather elliptical than circular. In the present paper we applied an asymmetric cone model to get the real space parameters of frontsided halo CMEs (HCMEs) recorded by SOHO/LASCO coronagraphs in 2002. The cone model parameters are generated through a fitting procedure to the projected speeds measured at different position angles on the plane of the sky. We consider models with the apex of the cone located at the center and surface of the Sun. The results are compared to the standard symmetric cone model.

  17. The luminosity -- halo-mass relation for brightest cluster galaxies

    E-Print Network [OSTI]

    Sarah Brough; Warrick Couch; Chris Collins; Doug Burke; Bob Mann

    2008-01-08T23:59:59.000Z

    We examine the central-galaxy luminosity -- host-halo mass relation for 54 Brightest Group Galaxies (BGGs) and 92 Brightest Cluster Galaxies (BCGs) at z<0.1 and present the first measurement of this relation for a sample of known BCGs at 0.1

  18. MAPPING THE STELLAR STRUCTURE OF THE MILKY WAY THICK DISK AND HALO USING SEGUE PHOTOMETRY

    SciTech Connect (OSTI)

    De Jong, Jelte T. A.; Rix, Hans-Walter; Martin, Nicolas F. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Yanny, Brian [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Beers, Timothy C., E-mail: dejong@mpia.d [Department of Physics and Astronomy and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)

    2010-05-01T23:59:59.000Z

    We map the stellar structure of the Galactic thick disk and halo by applying color-magnitude diagram (CMD) fitting to photometric data from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey. The SEGUE imaging scans allow, for the first time, a comprehensive analysis of Milky Way structure at both high and low latitudes using uniform Sloan Digital Sky Survey photometry. Incorporating photometry of all relevant stars simultaneously, CMD fitting bypasses the need to choose single tracer populations. Using old stellar populations of differing metallicities as templates, we obtain a sparse three-dimensional map of the stellar mass distribution at |Z|>1 kpc. Fitting a smooth Milky Way model comprising exponential thin and thick disks and an axisymmetric power-law halo allows us to constrain the structural parameters of the thick disk and halo. The thick-disk scale height and length are well constrained at 0.75 {+-} 0.07 kpc and 4.1 {+-} 0.4 kpc, respectively. We find a stellar halo flattening within {approx}25 kpc of c/a = 0.88 {+-} 0.03 and a power-law index of 2.75 {+-} 0.07 (for 7 kpc {approx_lt}R{sub GC} {approx_lt} 30 kpc). The model fits yield thick-disk and stellar halo densities at the solar location of {rho}{sub thick,sun} = 10{sup -2.3{+-}0.1} M{sub sun} pc{sup -3} and {rho}{sub halo,sun} = 10{sup -4.20{+-}0.05} M{sub sun} pc{sup -3}, averaging over any substructures. Our analysis provides the first clear in situ evidence for a radial metallicity gradient in the Milky Way's stellar halo: within R {approx_lt} 15 kpc the stellar halo has a mean metallicity of [Fe/H] {approx_equal} -1.6, which shifts to [Fe/H] {approx_equal} -2.2 at larger radii, in line with the two-component halo deduced by Carollo et al. from a local kinematic analysis. Subtraction of the best-fit smooth and symmetric model from the overall density maps reveals a wealth of substructures at all latitudes, some attributable to known streams and overdensities, and some new. A simple warp cannot account for the low latitude substructure, as overdensities occur simultaneously above and below the Galactic plane.

  19. Techniques for the measurement of disruption halo currents in the National Spherical Torus Experiment

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

    Gerhardt, S. P.; Fredrickson, E.; Guttadora, L.; Kaita, R.; Kugel, H.; Menard, J.; Takahashi, H.

    2011-01-01T23:59:59.000Z

    This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments. The measurements are based on three techniques: (i) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (ii) the direct measurement of halo currents into specially instrument tiles, and (iii) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peakingmore »factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems is shown.« less

  20. Non-local bias in the halo bispectrum with primordial non-Gaussianity

    E-Print Network [OSTI]

    Matteo Tellarini; Ashley J. Ross; Gianmassimo Tasinato; David Wands

    2015-04-01T23:59:59.000Z

    The statistics of large-scale structure in our Universe can discriminate between different scenarios for the origin of primordial density perturbations. Primordial non-Gaussianity can lead to a scale-dependent bias in the density of collapsed halos relative to the underlying matter density. The galaxy power spectrum already provides constraints on local-type primordial non-Gaussianity complementary to those from the cosmic microwave background, while the bispectrum contains additional shape information and has the potential to outperform CMB constraints in future. We develop the bias model for the halo density contrast in the presence of local-type primordial non-Gaussianity, deriving a bivariate expansion up to second order in terms of the local linear matter density contrast and the local gravitational potential in Lagrangian coordinates. We show how the evolution from linear to non-linear matter density introduces the non-local, tidal term in the halo model, while the presence of local-type non-Gaussianity in the Lagrangian frame generically leads to a novel non-local convective term in the Eulerian frame proportional to the displacement field, when going beyond the spherical collapse approximation. We use an extended Press-Schechter approach to evaluate the halo mass function and thus the halo bispectrum including these non-local terms and show that they can lead to corrections of up to $25\\%$ with respect to previous work for some configurations, on large scales or at high redshift.

  1. Beam halo formation from space-charge dominated beams in uniform focusing channels

    SciTech Connect (OSTI)

    O'Connell, J.S. (Booz, Allen and Hamilton, Inc., Arlington, VA (United States)); Wangler, T.P.; Mills, R.S. (Los Alamos National Lab., NM (United States)); Crandall, K.R. (AccSys Technology, Inc., Pleasanton, CA (United States))

    1993-01-01T23:59:59.000Z

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators.

  2. Beam halo formation from space-charge dominated beams in uniform focusing channels

    SciTech Connect (OSTI)

    O`Connell, J.S. [Booz, Allen and Hamilton, Inc., Arlington, VA (United States); Wangler, T.P.; Mills, R.S. [Los Alamos National Lab., NM (United States); Crandall, K.R. [AccSys Technology, Inc., Pleasanton, CA (United States)

    1993-06-01T23:59:59.000Z

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators.

  3. Techniques for the measurement of disruption halo currents in the National Spherical Torus Experiment

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

    Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Fredrickson, E. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Guttadora, L. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Kugel, H. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Menard, J. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Takahashi, H. [Princeton Fusion Research LLC, Princeton, NJ (United States)

    2011-10-06T23:59:59.000Z

    This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments [M. Ono, et. al, Nuclear Fusion 40, 557 (2000)]. The measurements are based on three techniques: (i) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (ii) the direct measurement of halo currents into specially instrument tiles, and (iii) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peaking factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems is shown.

  4. An extended Zel'dovich model for the halo mass function

    SciTech Connect (OSTI)

    Lim, Seunghwan; Lee, Jounghun, E-mail: shlim@astro.snu.ac.kr, E-mail: jounghun@astro.snu.ac.kr [Astronomy Program, FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2013-01-01T23:59:59.000Z

    A new way to construct a fitting formula for the halo mass function is presented. Our formula is expressed as a solution to the modified Jedamzik matrix equation that automatically satisfies the normalization constraint. The characteristic parameters expressed in terms of the linear shear eigenvalues are empirically determined by fitting the analytic formula to the numerical results from the high-resolution N-body simulation and found to be independent of scale, redshift and background cosmology. Our fitting formula with the best-fit parameters is shown to work excellently in the wide mass-range at various redshifts: The ratio of the analytic formula to the N-body results departs from unity by up to 10% and 5% over 10{sup 11} ? M/(h{sup ?1}M{sub s}un) ? 5 × 10{sup 15} at z = 0,0.5 and 1 for the FoF-halo and SO-halo cases, respectively.

  5. Possible signature of hypernova nucleosynthesis in a beryllium rich halo dwarf

    E-Print Network [OSTI]

    R. Smiljanic; L. Pasquini; F. Primas; P. Mazzali; D. Galli; G. Valle

    2008-01-07T23:59:59.000Z

    As part of a large survey of halo and thick disc stars, we found one halo star, HD 106038, exceptionally overabundant in beryllium. In spite of its low metallicity, [Fe/H] = -1.26, the star has log(Be/H) = -10.60, which is similar to the solar meteoritic abundance, log(Be/H) = -10.58. This abundance is more than ten times higher the abundance of stars with similar metallicity and cannot be explained by models of chemical evolution of the Galaxy that include the standard theory of cosmic-ray spallation. No other halo star exhibiting such a beryllium overabundance is known. In addition, overabundances of Li, Si, Ni, Y, and Ba are also observed. We suggest that all these chemical peculiarities, but the Ba abundance, can be simultaneously explained if the star was formed in the vicinity of a hypernova.

  6. Imprint of primordial non-Gaussianity on dark matter halo profiles

    SciTech Connect (OSTI)

    Dizgah, Azadeh Moradinezhad; Dodelson, Scott; Riotto, Antonio

    2013-09-01T23:59:59.000Z

    We study the impact of primordial non-Gaussianity on the density profile of dark matter halos by using the semi-analytical model introduced recently by Dalal {\\it et al.} which relates the peaks of the initial linear density field to the final density profile of dark matter halos. Models with primordial non-Gaussianity typically produce an initial density field that differs from that produced in Gaussian models. We use the path-integral formulation of excursion set theory to calculate the non-Gaussian corrections to the peak profile and derive the statistics of the peaks of non-Gaussian density field. In the context of the semi-analytic model for halo profiles, currently allowed values for primordial non-Gaussianity would increase the shapes of the inner dark matter profiles, but only at the sub-percent level except in the very innermost regions.

  7. Feedback from galactic stellar bulges and hot gaseous haloes of galaxies

    E-Print Network [OSTI]

    Shikui Tang; Q. Daniel Wang; Yu Lu; H. J. Mo

    2008-10-30T23:59:59.000Z

    We demonstrate that the feedback from stellar bulges can play an essential role in shaping the halo gas of galaxies with substantial bulge components by conducting 1-D hydrodynamical simulations. The feedback model we consider consists of two distinct phases: 1) an early starburst during the bulge formation and 2) a subsequent long-lasting mass and energy injection from stellar winds of low-mass stars and Type Ia SNe. An energetic outward blastwave is initiated by the starburst and is maintained and enhanced by the long-lasting stellar feedback. For a MW-like galactic bulge, this blastwave sweeps up the halo gas in the proto-galaxy and heats up the surrounding medium to a scale much beyond the virial radius of the halo, thus the accretion of the halo hot gas can be completely stopped. In addition, the long-lasting feedback in the later phase powers a galactic bulge wind that is reverse-shocked at a large radius in the presence of surrounding intergalactic medium and hence maintains a hot gaseous halo. As the mass and energy injection decreases with time, the feedback evolves to a subsonic and quasi-stable outflow, which is enough to prevent halo gas from cooling. The two phases of the feedback thus re-enforce each-other's impact on the gas dynamics. The simulation results demonstrate that the stellar bulge feedback may provide a plausible solution to the long-standing problems in understanding the MW type galaxies, such as the "missing stellar feedback" problem and the "over-cooling" problem. The simulations also show that the properties of the hot gas in the subsonic outflow state depend sensitively on the environment and the formation history of the bulge. This dependence and variance may explain the large dispersion in the X-ray to B-band luminosity ratio of the low $L_X/L_B$ Es.

  8. Changes in the halo formation rates due to features in the primordial spectrum

    E-Print Network [OSTI]

    Dhiraj Kumar Hazra

    2013-02-07T23:59:59.000Z

    Features in the primordial scalar power spectrum provide a possible roadway to describe the outliers at the low multipoles in the WMAP data. Apart from the CMB angular power spectrum, these features can also alter the matter power spectrum and, thereby, the formation of the large scale structure. Carrying out a complete numerical analysis, we investigate the effects of primordial features on the formation rates of the halos. We consider a few different inflationary models that lead to features in the scalar power spectrum and an improved fit to the CMB data, and analyze the corresponding imprints on the formation of halos. Performing a Markov Chain Monte Carlo analysis with the WMAP seven year data and the SDSS halo power spectrum from LRG DR7 for the models of our interest, we arrive at the parameter space of the models allowed by the data. We illustrate that, inflationary potentials, such as the quadratic potential with sinusoidal modulations and the axion monodromy model, which generate certain repeated, oscillatory features in the inflationary perturbation spectrum, do not induce a substantial difference in the number density of halos at their best fit values, when compared with, say, a nearly scale invariant spectrum as is generated by the standard quadratic potential. However, we find that the number density and the formation rates of halos change by about 13-22% for halo masses ranging over 10^4-10^14 solar mass, for potential parameters that lie within 2-sigma around the best fit values arrived at from the aforesaid joint constraints. We briefly discuss the implications of our results.

  9. Core excitation effects in halo nuclei using a transformed oscillator basis

    SciTech Connect (OSTI)

    Lay, J. A.; Arias, J. M.; Moro, A. M. [Departamento de FAMN, Facultad de Fisica, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla (Spain); Gomez-Camacho, J. [Departamento de FAMN, Facultad de Fisica, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla, Spain and Centro Nacional de Aceleradores, Avda. Thomas A. Edison, E-41092, Sevilla (Spain)

    2013-06-10T23:59:59.000Z

    A recent generalization of the Transformed Harmonic Oscillator basis, intended to consider core excitations in the structure of one nucleon halo nuclei, is applied to the break up of {sup 11}Be. The reaction studied is {sup 11}Be+{sup 208}Pb at 69 MeV/nucleon. The experimental set up is designed to ensure pure dipole Coulomb excitations. Making use of the Equivalent Photon Method and the electromagnetic transition probabilities obtained with the transformed oscillator basis, a relevant contribution of the quadrupole excitations of the core is found. The inclusion of core excitations is, therefore, necessary for the correct extraction of the dipole electromagnetic transition probability of halo nuclei.

  10. Enrichment of the r-process Element Europium in the Galactic Halo

    E-Print Network [OSTI]

    Yuhri Ishimaru; Shinya Wanajo

    1998-12-03T23:59:59.000Z

    We investigate the enrichment of europium, as a representative of r-process elements, in the Galactic halo. In present chemical evolution models, stars are assumed to be formed through shock processes by supernovae (SNe). The enrichment of the interstellar medium is calculated by a one-zone approach. The observed large dispersions in [Eu/Fe] for halo stars, converging with increasing metallicity, can be explained with our models. In addition, the mass range of SNe for the {\\it r}-process site is constrained to be either stars of $8-10 M_\\odot$ or $\\gtrsim 30 M_\\odot$.

  11. A skewer survey of the Galactic halo from deep CFHT and INT images

    E-Print Network [OSTI]

    Pila-Díez, B; Kuijken, K; van der Burg, R F J; Hoekstra, H

    2015-01-01T23:59:59.000Z

    We study the density profile and shape of the Galactic halo using deep multicolour images from the MENeaCS and CCCP projects, over 33 fields selected to avoid overlap with the Galactic plane. Using multicolour selection and PSF homogenization techniques we obtain catalogues of F stars (near-main sequence turnoff stars) out to Galactocentric distances up to 60kpc. Grouping nearby lines of sight, we construct the stellar density profiles through the halo in eight different directions by means of photometric parallaxes. Smooth halo models are then fitted to these profiles. We find clear evidence for a steepening of the density profile power law index around R=20 kpc, from -2.50 +- 0.04 to -4.85 +- 0.04, and for a flattening of the halo towards the poles with best-fit axis ratio 0.63 +- 0.02. Furthermore, we cannot rule out a mild triaxiality (w>=0.8). We recover the signatures of well-known substructure and streams that intersect our lines of sight. These results are consistent with those derived from wider but ...

  12. MHD wave refraction and the acoustic halo effect around solar active regions - a 3D study

    E-Print Network [OSTI]

    Rijs, Carlos; Przybylski, Damien; Cally, Paul S

    2015-01-01T23:59:59.000Z

    An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to ascertain whether the formation of the acoustic halo is caused by MHD mode conversion through regions of moderate and inclined magnetic fields. This conversion type is most efficient when high frequency waves from below intersect magnetic field lines at a large angle. We find a strong relationship between halo formation and the equipartition surface at which the Alfv\\'en speed $a$ matches the sound speed $c$, lending support to the theory that photospheric and chromospheric halo enhancement is due to the creation and subsequent reflection of magnetically dominated fast waves from essentially acoustic waves as they cross $a=c$. In simulations where we have capped $a$ such that waves are not permitted to refract after reaching the $a=c$ height, halos are non-existent, which su...

  13. Direct Gravitational Imaging of Intermediate Mass Black Holes in Extragalactic Halos

    E-Print Network [OSTI]

    Kaiki Taro Inoue; Valery Rashkov; Joseph Silk; Piero Madau

    2013-01-22T23:59:59.000Z

    A galaxy halo may contain a large number of intermediate mass black holes (IMBHs) with masses in the range of 10^{2-6} solar mass. We propose to directly detect these IMBHs by observing multiply imaged QSO-galaxy or galaxy-galaxy strong lens systems in the submillimeter bands with high angular resolution. The silhouette of an IMBH in the lensing galaxy halo would appear as either a monopole-like or a dipole-like variation at the scale of the Einstein radius against the Einstein ring of the dust-emitting region surrounding the QSO. We use a particle tagging technique to dynamically populate a Milky Way-sized dark matter halo with black holes, and show that the surface mass density and number density of IMBHs have power-law dependences on the distance from the center of the host halo if smoothed on a scale of ~ 1 kpc. Most of the black holes orbiting close to the center are freely roaming as they have lost their dark matter hosts during infall due to tidal stripping. Next generation submillimeter telescopes with high angular resolution (solar mass in a lensing galaxy that harbours a O(10^9) solar mass supermassive black hole in its nucleus.

  14. Role of Higher Multipole Excitations in the Electromagnetic Dissociation of One Neutron Halo Nuclei

    E-Print Network [OSTI]

    R. Chatterjee; L. Fortunato; A. Vitturi

    2007-12-20T23:59:59.000Z

    We investigate the role of higher multipole excitations in the electromagnetic dissociation of one-neutron halo nuclei within two different theoretical models -- a finite range distorted wave Born approximation and another in a more analytical method with a finite range potential. We also show, within a simple picture, how the presence of a weakly bound state affects the breakup cross section.

  15. ELECTRON HALO AND STRAHL FORMATION IN THE SOLAR WIND BY RESONANT INTERACTION WITH WHISTLER WAVES

    E-Print Network [OSTI]

    California at Berkeley, University of

    . A thermal core and a suprathermal halo and antisunward, magnetic field­aligned beam, or ``strahl,'' can- trons in the solar corona and wind, including resonant interaction between electrons and whistler waves, can repro- duce an enhancement of suprathermal electron fluxes compared to the core flux. The whistler

  16. Rare measurements of a sprite with halo event driven by a negative lightning discharge over Argentina

    E-Print Network [OSTI]

    Thomas, Jeremy N.

    Argentina M. J. Taylor,1 M. A. Bailey,1 P. D. Pautet,1 S. A. Cummer,2 N. Jaugey,2 J. N. Thomas,3,4 N. N measurements were made of a mesoscale thunderstorm observed on February 22­23, 2006 over northern Argentina of a sprite with halo event driven by a negative lightning discharge over Argentina, Geophys. Res. Lett., 35

  17. X-ray Dust Scattering at Small Angles: The Complete Halo around GX13+1

    E-Print Network [OSTI]

    Randall K. Smith

    2008-05-04T23:59:59.000Z

    The exquisite angular resolution available with Chandra should allow precision measurements of faint diffuse emission surrounding bright sources, such as the X-ray scattering halos created by interstellar dust. However, the ACIS CCDs suffer from pileup when observing bright sources, and this creates difficulties when trying to extract the scattered halo near the source. The initial study of the X-ray halo around GX13+1 using only the ACIS-I detector done by Smith, Edgar & Shafer (2002) suffered from a lack of sensitivity within 50'' of the source, limiting what conclusions could be drawn. To address this problem, observations of GX13+1 were obtained with the Chandra HRC-I and simultaneously with the RXTE PCA. Combined with the existing ACIS-I data, this allowed measurements of the X-ray halo between 2-1000''. After considering a range of dust models, each assumed to be smoothly distributed with or without a dense cloud along the line of sight, the results show that there is no evidence in this data for a dense cloud near the source, as suggested by Xiang et al. (2005). Finally, although no model leads to formally acceptable results, the Weingartner & Draine (2001) and nearly all of the composite grain models from Zubko, Dwek & Arendt (2004) give poor fits.

  18. Application of Diamond and Sapphire Sensors in the Beam Halo Monitor for FLASH

    E-Print Network [OSTI]

    , ionization chambers, a beam halo monitor (BHM) and beam position monitors (BPM) has been installed. The BHM, a BHM system and a magnetic BPM (also called "in-air" BPM) [8] operating in conjunction in order not hit the beam pipe downstream from the exit window. The BPM detects the center of gravity of the beam

  19. Search for emission lines in the gaseous halo of edge-on galaxies

    SciTech Connect (OSTI)

    Bixler, J.

    1984-09-01T23:59:59.000Z

    Careful reductions of the short wave prime camera (SWP) spectrum was carried out. A line by line inspection of the spectrum was used to eliminate spurious spikes and a median filter applied to eliminate high frequency noise. Upper limits were obtained for far ultraviolet emission from a hot galactic halo.

  20. Resonant Trapping in the Galactic Disc and Halo and its Relation with Moving Groups

    E-Print Network [OSTI]

    Moreno, Edmundo; Schuster, William

    2015-01-01T23:59:59.000Z

    With the use of a detailed Milky Way nonaxisymmetric potential, observationally and dynamically constrained, the e?ects of the bar and the spiral arms in the Galaxy are studied in the disc and in the stellar halo. Especially the trapping of stars in the disc and Galactic halo by resonances on the Galactic plane, induced by the Galactic bar, has been analysed in detail. To this purpose, a new method is presented to delineate the trapping regions using empirical diagrams of some orbital properties obtained in the Galactic potential. In these diagrams we plot in the inertial Galactic frame a characteristic orbital energy versus a characteristic orbital angular momentum, or versus the orbital Jacobi constant in the reference frame of the bar, when this is the only nonaxisymmetric component in the Galactic potential. With these diagrams some trapping regions are obtained in the disc and halo using a sample of disc stars and halo stars in the solar neighbourhood. We compute several families of periodic orbits on th...

  1. The Old Halo metallicity gradient: the trace of a self-enrichment process

    E-Print Network [OSTI]

    G. Parmentier; E. Jehin; P. Magain; A. Noels; A. Thoul

    2000-09-29T23:59:59.000Z

    Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment model is based on the ability of globular cluster progenitor clouds to retain the ejecta of a first generation of Type II Supernovae. The key point is that this ability depends on the pressure exerted on the progenitor cloud by the surrounding protogalactic medium and therefore on the location of the cloud in the protoGalaxy. Since there is no significant (if any) metallicity gradient in the whole halo, we also present a review in favour of a galactic halo partly build via accretions and mergers of satellite systems. Some of them bear their own globular clusters and therefore ``contaminate'' the system of globular clusters formed ``in situ'', namely within the original potential well of the Galaxy. Therefore, the comparison between our self-enrichment model and the observational data should be limited to the genuine galactic globular clusters, the so-called Old Halo group.

  2. Fish Passage Through a Simulated Horizontal Bulb Turbine Pressure Regime: A Supplement to"Laboratory Studies of the Effects of Pressure and Dissolved Gas Supersaturation on Turbine-Passed Fish"

    SciTech Connect (OSTI)

    Abernethy, Cary S. (BATTELLE (PACIFIC NW LAB)); Amidan, Brett G. (BATTELLE (PACIFIC NW LAB)); Cada, G F. (ORNL)

    2003-07-31T23:59:59.000Z

    Migratory and resident fish in the Columbia River Basin are exposed to stresses associated with hydroelectric power production, including pressure changes during turbine passage. The responses of fall chinook salmon and bluegill sunfish to rapid pressure change was investigated at the Pacific Northwest National Laboratory. Previous test series evaluated the effects of passage through a vertical Kaplan turbine under the"worst case" pressure conditions and under less severe conditions where pressure changes were minimized. For this series of tests, pressure changes were modified to simulate passage through a horizontal bulb turbine, commonly installed at low head dams. The results were compared to results from previous test series. Migratory and resident fish in the Columbia River Basin are exposed to stresses associated with hydroelectric power production, including pressure changes during turbine passage. The responses of fall chinook salmon and bluegill sunfish to rapid pressure change was investigated at the Pacific Northwest National Laboratory. Previous test series evaluated the effects of passage through a vertical Kaplan turbine under the"worst case" pressure conditions and under less severe conditions where pressure changes were minimized. For this series of tests, pressure changes were modified to simulate passage through a horizontal bulb turbine, commonly installed at low head dams. The results were compared to results from previous test series. Both fish species were acclimated for 16-22 hours at either surface (101 kPa; 1 atm) or 30 ft (191 kPa; 1.9 atm) of pressure in a hyperbaric chamber before exposure to a pressure scenario simulating passage through a horizontal bulb turbine. The simulation was as follows: gradual pressure increase to about 2 atm of pressure, followed by a sudden (0.4 second) decrease in pressure to either 0.7 or 0.95 atm, followed by gradual return to 1 atm (surface water pressure). Following the exposure, fish were held at surface pressure for a 48-hour post exposure observation period. No fall chinook salmon died during or after exposure to the horizontal bulb turbine passage pressures, and no injuries were observed during the 48-hour post exposure observation period. As with the previous test series, it cannot be determined whether fall chinook salmon acclimated to the greater water pressure during the pretest holding period. For bluegill sunfish exposed to the horizontal bulb turbine turbine-passage pressures, only one fish died and injuries were less severe and less common than for bluegills subjected to either the"worst case" pressure or modified Kaplan turbine pressure conditions in previous tests. Injury rates for bluegills were higher at 0.7 atm nadir than for the 0.95 atm nadir. However, injuries were limited to minor internal hemorrhaging. Bluegills did not suffer swim bladder rupture in any tested scenarios. Tests indicated that for most of the cross-sectional area of a horizontal bulb turbine, pressure changes occurring during turbine passage are not harmful to fall chinook salmon and only minimally harmful to bluegill. However, some areas within a horizontal bulb turbine may have extreme pressure conditions that would be harmful to fish. These scenarios were not tested because they represent a small cross-sectional area of the turbine compared to the centerline pressures scenarios used in these tests.

  3. Galaxy Galaxy Lensing as a Probe of Galaxy Dark Matter Halos

    E-Print Network [OSTI]

    M. Limousin; J-P. Kneib; P. Natarajan

    2006-06-19T23:59:59.000Z

    Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques: observing the shapes of distant background galaxies which have been lensed by foreground galaxies allows us to map the mass distribution of the foreground galaxies. The lensing effect is small compared to the intrinsic ellipticity distribution of galaxies, thus a statistical approach is needed to derive some constraints on an average lens population. An advantage of this method is that it provides a probe of the gravitational potential of the halos of galaxies out to very large radii, where few classical methods are viable, since dynamical and hydrodynamical tracers of the potential cannot be found at this radii. We will begin by reviewing the detections of galaxy-galaxy lensing obtained so far. Next we will present a maximum likelihood analysis of simulated data we performed to evaluate the accuracy and robustness of constraints that can be obtained on galaxy halo properties. Then we will apply this method to study the properties of galaxies which stand in massive cluster lenses at z~0.2. The main result of this work is to find dark matter halos of cluster galaxies to be significantly more compact compared to dark matter halos around field galaxies of equivalent luminosity, in agreement with early galaxy-galaxy lensing studies and with theoretical expectations, in particular with the tidal stripping scenario. We thus provide a strong confirmation of tidal truncation from a homogeneous sample of galaxy clusters. Moreover, it is the first time that cluster galaxies are probed successfully using galaxy-galaxy lensing techniques from ground based data.

  4. Distribution function approach to redshift space distortions. Part III: halos and galaxies

    SciTech Connect (OSTI)

    Okumura, Teppei; Seljak, Uroš [Institute for the Early Universe, Ewha Womans University, Seoul 120-750, S. Korea (Korea, Republic of); Desjacques, Vincent, E-mail: teppei@ewha.ac.kr, E-mail: useljak@berkeley.edu, E-mail: dvince@physik.uzh.ch [Département de Physique Théorique and Center for Astroparticle Physics (CAP), Université de Genève, 1211 Genève (Switzerland)

    2012-11-01T23:59:59.000Z

    It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments, of which the lowest are density and momentum density. We investigate numerically the properties of these power spectra for simulated galaxies and dark matter halos and compare them to the dark matter power spectra, generalizing the concept of the bias in density-density power spectra. Because all of the quantities are number weighted this approach is well defined even for sparse systems such as massive halos. This contrasts to the previous approaches to RSD where velocity correlations have been explored, but velocity field is a poorly defined concept for sparse systems. We find that the number density weighting leads to a strong scale dependence of the bias terms for momentum density auto-correlation and cross-correlation with density. This trend becomes more significant for the more biased halos and leads to an enhancement of RSD power relative to the linear theory. Fingers-of-god effects, which in this formalism come from the correlations of the higher order moments beyond the momentum density, lead to smoothing of the power spectrum and can reduce this enhancement of power from the scale dependent bias, but are relatively small for halos with no small scale velocity dispersion. In comparison, for a more realistic galaxy sample with satellites the small scale velocity dispersion generated by satellite motions inside the halos leads to a larger power suppression on small scales, but this depends on the satellite fraction and on the details of how the satellites are distributed inside the halo. We investigate several statistics such as the two-dimensional power spectrum P(k,?), where ? is the angle between the Fourier mode and line of sight, its multipole moments, its powers of ?{sup 2}, and configuration space statistics. Overall we find that the nonlinear effects in realistic galaxy samples such as luminous red galaxies affect the redshift space clustering on very large scales: for example, the quadrupole moment is affected by 10% for k < 0.1hMpc{sup ?1}, which means that these effects need to be understood if we want to extract cosmological information from the redshift space distortions.

  5. USING THE X-RAY DUST SCATTERING HALO OF CYGNUS X-1 TO DETERMINE DISTANCE AND DUST DISTRIBUTIONS

    E-Print Network [OSTI]

    Xiang, Jingen

    We present a detailed study of the X-ray dust scattering halo of the black hole candidate Cygnus X-1 based on two Chandra High Energy Transmission Gratings Spectrometer observations. Using 18 different dust models, including ...

  6. Quantifying the Cosmic Web I: The large-scale halo ellipticity-ellipticity and ellipticity-direction correlations

    E-Print Network [OSTI]

    Jounghun Lee; Volker Springel; Ue-Li Pen; Gerard Lemson

    2008-06-20T23:59:59.000Z

    The formation of dark matter halos tends to occur anisotropically along the filaments of the Cosmic Web, which induces both ellipticity-ellipticity (EE) correlations between the shapes of halos, as well as ellipticity-direction (ED) cross-correlations between halo shapes and the directions to neighboring halos. We analyze the halo catalogue and the semi-analytic galaxy catalogue of the recent Millennium Run Simulation to measure the EE and ED correlations numerically at four different redshifts (z=0, 0.5, 1 and 2). For the EE correlations, we find that (i) the major-axis correlation is strongest while the intermediate-axis correlation is weakest; (ii) the signal is significant at distances out to 10 Mpc/h; (iii) the signal decreases as z decreases; (iv) and its behavior depends strongly on the halo mass scale, with larger masses showing stronger correlations at large distances. For the ED correlations, we find that (i) the correlations are much stronger than the EE correlations, and are significant even out to distances of 50 Mpc/h; (ii) the signal also decreases as z decreases; (iii) and it increases with halo mass at all distances. We also provide empirical fitting functions for the EE and ED correlations. The EE correlations are found to scale linearly with the linear density correlation function, xi(r). While the ED cross-correlation is found to scale as xi^{1/2}(r) at large distances beyond 10 Mpc/h. The best-fit values of the fitting parameters for the EE and the ED correlations are all determined through chi^{2}-statistics. Our results may be useful for quantifying the filamentary distribution of dark matter halos over a wide range of scales.

  7. The X-ray Halo of G21.5-0.9

    E-Print Network [OSTI]

    R. Bandiera; F. Bocchino

    2003-05-21T23:59:59.000Z

    The emission of the plerion G21.5-0.9 appears more extended in X rays than in radio. This is an unexpected result because it would imply that short-lived X-ray electrons may reach distances even larger than radio electrons. Applying an empirical relationship between dust scattering optical depth and photoelectric column density, the measured column density leads to a large optical depth at 1 keV, of about 1. Therefore we investigate the hypothesis that the detected halo be an effect of dust scattering, re-analyzing an Cal/PV XMM-Newton observation of G21.5-0.9 and critically examining it in terms of a dust scattering model. We also present a spectral analysis of a prominent extended feature in the northern sector of the halo.

  8. The modified dynamics (MOND) predicts an absolute maximum to the acceleration produced by `dark halos'

    E-Print Network [OSTI]

    Rafael Brada; Mordehai Milgrom

    1998-12-21T23:59:59.000Z

    We have recently discovered that the modified dynamics (MOND) implies some universal upper bound on the acceleration that can be contributed by a `dark halo'--assumed in a Newtonian analysis to account for the effects of MOND. Not surprisingly, the limit is of the order of the acceleration constant of the theory. This can be contrasted directly with the results of structure-formation simulations. The new limit is substantial and different from earlier MOND acceleration limits (discussed in connection with the MOND explanation of the Freeman law for galaxy disks, and the Fish law for ellipticals): It pertains to the `halo', and not to the observed galaxy; it is absolute, and independent of further physical assumptions on the nature of the galactic system; and it applies at all radii, whereas the other limits apply only to the mean acceleration in the system.

  9. The Self-Enrichment of Galactic Halo Globular Clusters: the mass-metallicity relation

    E-Print Network [OSTI]

    G. Parmentier; G. Gilmore

    2001-08-28T23:59:59.000Z

    We discuss the existence of a mass-metallicity relation among galactic halo globular clusters. The lack of any luminosity-metallicity correlation in globular cluster systems has been used as an argument against self-enrichment models of cluster formation. We show that such a relation is statistically present among the galactic Old Halo globulars. This observational correlation implies that the least massive old clusters are the most metal-rich. This is in contradiction with the idea that, if globular clusters were self-enriched systems, the most metal-rich clusters would also be the most massive ones. We further show that this anti-correlation is as predicted by self-enrichment models.

  10. HOT GAS HALOS AROUND DISK GALAXIES: CONFRONTING COSMOLOGICAL SIMULATIONS WITH OBSERVATIONS

    SciTech Connect (OSTI)

    Rasmussen, Jesper [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sommer-Larsen, Jesper [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstr. 2, D-85748 Garching bei Muenchen (Germany); Pedersen, Kristian; Toft, Sune; Grove, Lisbeth F. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Benson, Andrew [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Mail Code 130-33, Pasadena, CA 91125 (United States); Bower, Richard G. [Institute for Computational Cosmology, University of Durham, South Road, Durham DH1 3LE (United Kingdom)], E-mail: jr@ociw.edu

    2009-05-20T23:59:59.000Z

    Models of disk galaxy formation commonly predict the existence of an extended reservoir of accreted hot gas surrounding massive spirals at low redshift. As a test of these models, we use X-ray and H{alpha} data of the two massive, quiescent edge-on spirals NGC 5746 and NGC 5170 to investigate the amount and origin of any hot gas in their halos. Contrary to our earlier claim, the Chandra analysis of NGC 5746, employing more recent calibration data, does not reveal any significant evidence for diffuse X-ray emission outside the optical disk, with a 3{sigma} upper limit to the halo X-ray luminosity of 4 x 10{sup 39} erg s{sup -1}. An identical study of the less massive NGC 5170 also fails to detect any extraplanar X-ray emission. By extracting hot halo properties of disk galaxies formed in cosmological hydrodynamical simulations, we compare these results to expectations for cosmological accretion of hot gas by spirals. For Milky-Way-sized galaxies, these high-resolution simulations predict hot halo X-ray luminosities which are lower by a factor of {approx}2 compared to our earlier results reported by Toft et al. We find the new simulation predictions to be consistent with our observational constraints for both NGC 5746 and NGC 5170, while also confirming that the hot gas detected so far around more actively star-forming spirals is in general probably associated with stellar activity in the disk. Observational results on quiescent disk galaxies at the high-mass end are nevertheless providing powerful constraints on theoretical predictions, and hence on the assumed input physics in numerical studies of disk galaxy formation and evolution.

  11. Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions

    SciTech Connect (OSTI)

    Alkhazov, G. D.; Sarantsev, V. V., E-mail: saran@pnpi.spb.ru [Petersburg Nuclear Physics Institute NRC KI (Russian Federation)

    2012-12-15T23:59:59.000Z

    In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.

  12. The Dark Matter distribution function and Halo Thermalization from the Eddington equation in Galaxies

    E-Print Network [OSTI]

    H. J. de Vega; N. G. Sanchez

    2015-02-04T23:59:59.000Z

    We find the distribution function f(E) for dark matter (DM) halos in galaxies and the corresponding equation of state from the (empirical) DM density profiles derived from observations. We solve for DM in galaxies the analogous of the Eddington equation originally used for the gas of stars in globular clusters. The observed density profiles are a good realistic starting point and the distribution functions derived from them are realistic. We do not make any assumption about the DM nature, the methods developed here apply to any DM kind, though all results are consistent with Warm DM. With these methods we find: (i) Cored density profiles behaving quadratically for small distances rho(r) r -> 0 = rho(0) - K r^2 produce distribution functions which are finite and positive at the halo center while cusped density profiles always produce divergent distribution functions at the center. (ii) Cored density profiles produce approximate thermal Boltzmann distribution functions for r gas equation of state with local temperature T(r) = m v^2(r)/3. T(r) turns to be constant in the same region where the distribution function is thermal and exhibits the same temperature within the percent. The self-gravitating DM gas can thermalize despite being collisionless because it is an ergodic system. (iv) The DM halo can be consistently considered at local thermal equilibrium with: (a) a constant temperature T(r) = T_0 for r gas for r < R_{virial}. (v) T(r) outside the halo radius nicely follows the decrease of the circular velocity squared.

  13. The outer regions of the giant Virgo galaxy M87 II. Kinematic separation of stellar halo and intracluster light

    E-Print Network [OSTI]

    Longobardi, Alessia; Gerhard, Ortwin; Hanuschik, Reinhard

    2015-01-01T23:59:59.000Z

    We present a spectroscopic study of 287 Planetary Nebulas (PNs) in a total area of ~0.4 deg^2 around the BCG M87 in Virgo A. With these data we can distinguish the stellar halo from the co-spatial intracluster light (ICL). PNs were identified from their narrow and symmetric redshifted lambda 5007\\4959 Angstrom [OIII] emission lines, and the absence of significant continuum. We implement a robust technique to measure the halo velocity dispersion from the projected phase-space to identify PNs associated with the M87 halo and ICL. The velocity distribution of the spectroscopically confirmed PNs is bimodal, containing a narrow component centred on the systemic velocity of the BCG and an off-centred broader component, that we identify as halo and ICL, respectively. Halo and ICPN have different spatial distributions: the halo PNs follow the galaxy's light, whereas the ICPNs are characterised by a shallower power-law profile. The composite PN number density profile shows the superposition of different PN populations...

  14. Genetically modified halos: towards controlled experiments in $\\Lambda$CDM galaxy formation

    E-Print Network [OSTI]

    Roth, Nina; Peiris, Hiranya V

    2015-01-01T23:59:59.000Z

    We propose a method to generate `genetically-modified' (GM) initial conditions for high-resolution simulations of galaxy formation in a cosmological context. Building on the Hoffman-Ribak algorithm, we start from a reference simulation with fully random initial conditions, then make controlled changes to specific properties of a single halo (such as its mass and merger history). The algorithm demonstrably makes minimal changes to other properties of the halo and its environment, allowing us to isolate the impact of a given modification. As a significant improvement over previous work, we are able to calculate the abundance of the resulting objects relative to the $\\Lambda$CDM reference cosmology. Our approach can be applied to a wide range of cosmic structures and epochs; here we study two problems as a proof-of-concept. First, we investigate the change in density profile and concentration as the collapse time of three individual halos are varied at fixed final mass, showing good agreement with previous stati...

  15. Tracing the Metal-Poor M31 Stellar Halo with Blue Horizontal Branch Stars

    E-Print Network [OSTI]

    Williams, Benjamin F; Gilbert, Eric F BellKaroline M; Guhathakurta, Puragra; Dorman, Claire; Lauer, Tod R; Seth, Anil C; Kalirai, Jason S; Rosenfield, Philip; Girardi, Leo

    2015-01-01T23:59:59.000Z

    We have analyzed new HST/ACS and HST/WFC3 imaging in F475W and F814W of two previously-unobserved fields along the M31 minor axis to confirm our previous constraints on the shape of M31's inner stellar halo. Both of these new datasets reach a depth of at least F814W$blue horizontal branch (BHB) of the field as a distinct feature of the color-magnitude diagram. We measure the density of BHB stars and the ratio of BHB to red giant branch stars in each field using identical techniques to our previous work. We find excellent agreement with our previous measurement of a power-law for the 2-D projected surface density with an index of 2.6$^{+0.3}_{-0.2}$ outside of 3 kpc, which flattens to $\\alpha <$1.2 inside of 3 kpc. Our findings confirm our previous suggestion that the field BHB stars in M31 are part of the halo population. However, the total halo profile is now known to differ from this BHB profile, which suggests that we have isolated the metal-poor component. This component ...

  16. Fusion and Direct Reactions of Halo Nuclei at Energies around the Coulomb Barrier

    E-Print Network [OSTI]

    N. Keeley; R. Raabe; N. Alamanos; J. L. Sida

    2007-02-16T23:59:59.000Z

    The present understanding of reaction processes involving light unstable nuclei at energies around the Coulomb barrier is reviewed. The effect of coupling to direct reaction channels on elastic scattering and fusion is investigated, with the focus on halo nuclei. A list of definitions of processes is given, followed by a review of the experimental and theoretical tools and information presently available. The effect of couplings on elastic scattering and fusion is studied with a series of model calculations within the coupled-channels framework. The experimental data on fusion are compared to "bare" no-coupling one-dimensional barrier penetration model calculations. On the basis of these calculations and comparisons with experimental data, conclusions are drawn from the observation of recurring features. The total fusion cross sections for halo nuclei show a suppression with respect to the "bare" calculations at energies just above the barrier that is probably due to single neutron transfer reactions. The data for total fusion are also consistent with a possible sub-barrier enhancement; however, this observation is not conclusive and other couplings besides the single-neutron channels would be needed in order to explain any actual enhancement. We find that a characteristic feature of halo nuclei is the dominance of direct reactions over fusion at near and sub-barrier energies; the main part of the cross section is related to neutron transfers, while calculations indicate only a modest contribution from the breakup process.

  17. The effect of stellar feedback on a Milky Way-like galaxy and its gaseous halo

    E-Print Network [OSTI]

    Marasco, Antonino; Fraternali, Filippo; van der Hulst, Thijs; Wadsley, James; Quinn, Thomas; Roškar, Rok

    2015-01-01T23:59:59.000Z

    We present the study of a set of N-body+SPH simulations of a Milky Way-like system produced by the radiative cooling of hot gas embedded in a dark matter halo. The galaxy and its gaseous halo evolve for 10 Gyr in isolation, which allows us to study how internal processes affect the evolution of the system. We show how the morphology, the kinematics and the evolution of the galaxy are affected by the input supernova feedback energy E$_{\\rm SN}$, and we compare its properties with those of the Milky Way. Different values of E$_{\\rm SN}$ do not significantly affect the star formation history of the system, but the disc of cold gas gets thicker and more turbulent as feedback increases. Our main result is that, for the highest value of E$_{\\rm SN}$ considered, the galaxy shows a prominent layer of extra-planar cold (log(T)<4.3) gas extended up to a few kpc above the disc at column densities of $10^{19}$ cm$^{-2}$. The kinematics of this material is in agreement with that inferred for the HI halos of our Galaxy ...

  18. Halo and Bulge/Disk globular clusters in the S0 galaxy NGC 1380

    E-Print Network [OSTI]

    Markus Kissler-Patig; Tom Richtler; Jesper Storm; Massimo Della Valle

    1997-06-30T23:59:59.000Z

    We investigated the globular cluster system of the S0 galaxy NGC 1380 in the Fornax cluster with deep BVR photometry. We identified two, presumably old, populations of globular clusters. The blue globular clusters seem to be counterparts to the halo globular clusters in our Milky Way. They have comparable colors and magnitudes, are spherically distributed around the elliptical galaxy but have a very flat surface density profile. The red population follows the stellar light in ellipticity and position angle, has a similar magnitude distribution to the blue clusters, and a surface density profile comparable to that of globular clusters in other Fornax ellipticals. From their colors the red clusters appear slightly more metal rich then the metal rich globular clusters in the Milky way. We associate this red population with the bulge and disk of NGC 1380. While these two populations are compatible with a merger formation, we unfortunately see no other hint in favor nor against a past merger event in this galaxy. This would be the first identification of halo and bulge globular clusters in an early--type galaxy by their colors and spatial distribution, and could hint to the presence of halo and bulge globular clusters in all galaxies.

  19. Non-local bias in the halo bispectrum with primordial non-Gaussianity

    E-Print Network [OSTI]

    Tellarini, Matteo; Tasinato, Gianmassimo; Wands, David

    2015-01-01T23:59:59.000Z

    The statistics of large-scale structure in our Universe can discriminate between different scenarios for the origin of primordial density perturbations. Primordial non-Gaussianity can lead to a scale-dependent bias in the density of collapsed halos relative to the underlying matter density. The galaxy power spectrum already provides constraints on local-type primordial non-Gaussianity complementary to those from the cosmic microwave background, while the bispectrum contains additional shape information and has the potential to outperform CMB constraints in future. We develop the bias model for the halo density contrast in the presence of local-type primordial non-Gaussianity, deriving a bivariate expansion up to second order in terms of the local linear matter density contrast and the local gravitational potential in Lagrangian coordinates. We show how the evolution from linear to non-linear matter density introduces the non-local, tidal term in the halo model, while the presence of local-type non-Gaussianity...

  20. The First Population II Stars Formed in Externally Enriched Mini-halos

    E-Print Network [OSTI]

    Smith, Britton; O'Shea, Brian; Norman, Michael; Khochfar, Sadegh

    2015-01-01T23:59:59.000Z

    We present a simulation of the formation of the earliest Population II stars, starting from cosmological initial conditions and ending when metals created in the first supernovae are incorporated into a collapsing gas-cloud. This occurs after a supernova blast-wave collides with a nearby mini-halo, inducing further turbulence that efficiently mixes metals into the dense gas in the center of the halo. The gas that first collapses has been enriched to a metallicity of Z ~ 2e-5 Zsun. Due to the extremely low metallicity, collapse proceeds similarly to metal-free gas until dust cooling becomes efficient at high densities, causing the cloud to fragment into a large number of low mass objects. This external enrichment mechanism provides a plausible origin for the most metal-poor stars observed, such as SMSS J031300.36-670839.3, that appear to have formed out of gas enriched by a single supernova. This mechanism operates on shorter timescales than the time for low-mass mini-halos (M < 5e5 Msun) to recover their g...

  1. Ongoing Galactic Accretion: Simulations and Observations of Condensed Gas in Hot Halos

    E-Print Network [OSTI]

    J. E. G. Peek; M. E. Putman; Jesper Sommer-Larsen

    2007-09-11T23:59:59.000Z

    Ongoing accretion onto galactic disks has been recently theorized to progress via the unstable cooling of the baryonic halo into condensed clouds. These clouds have been identified as analogous to the High-Velocity Clouds (HVCs) observed in HI in our Galaxy. Here we compare the distribution of HVCs observed around our own Galaxy and extra-planar gas around the Andromeda galaxy to these possible HVC analogs in a simulation of galaxy formation that naturally generates these condensed clouds. We find a very good correspondence between these observations and the simulation, in terms of number, angular size, velocity distribution, overall flux and flux distribution of the clouds. We show that condensed cloud accretion only accounts for ~ 0.2 M_solar / year of the current overall Galactic accretion in the simulations. We also find that the simulated halo clouds accelerate and become more massive as they fall toward the disk. The parameter space of the simulated clouds is consistent with all of the observed HVC complexes that have distance constraints, except the Magellanic Stream which is known to have a different origin. We also find that nearly half of these simulated halo clouds would be indistinguishable from lower-velocity gas and that this effect is strongest further from the disk of the galaxy, thus indicating a possible missing population of HVCs. These results indicate that the majority of HVCs are consistent with being infalling, condensed clouds that are a remnant of Galaxy formation.

  2. Penile bulb dose and impotence after three-dimensional conformal radiotherapy for prostate cancer on RTOG 9406: Findings from a prospective, multi-institutional, phase I/II dose-escalation study

    SciTech Connect (OSTI)

    Roach, Mack [University of California San Francisco, San Francisco, CA (United States)]. E-mail: roach@radonc17.ucsf.edu; Winter, Kathryn [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Michalski, Jeffrey M. [Washington University, St. Louis, MO (United States); Cox, James D. [3D Quality Assurance Center at Washington University St. Louis, MO (United States); Purdy, James A. [University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Bosch, Walter [University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Lin Xiao [University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Shipley, William S. [Massachusetts General Hospital, Boston MA (United States)

    2004-12-01T23:59:59.000Z

    Purpose: To assess the relationship between the dose to the bulb of the penis and the risk of impotence in men treated on Radiation Therapy Oncology Group (RTOG) 9406. Methods and materials: Men enrolled on a Phase I/II dose-escalation study, RTOG 9406, who were reported to be potent at entry and evaluable (n = 158) were selected for inclusion. Follow-up evaluations were scheduled every 3, 4, and 6 months for the first, second, and the third through fifth years, then annually. At each follow-up visit an assessment of potency status was made. Penile structures were defined by a single observer blinded to the potency status, using Web-based, on-line software. The dosimetry for penile structures was calculated at the Quality Assurance Center at Washington University and provided to RTOG Statistical Headquarters to determine whether there was a relationship between dose and impotence. Results: Patients whose median penile dose was {>=}52.5 Gy had a greater risk of impotence compared with those receiving <52.5 Gy (p = 0.039). In a multivariate analysis neither age, the dose to the prostate, nor the use of hormonal therapy correlated with the risk of impotence. Conclusions: Dose to the bulb of the penis seems to be associated with the risk of radiation-induced impotence.

  3. NIHAO project II: Halo shape, phase-space density and velocity distribution of dark matter in galaxy formation simulations

    E-Print Network [OSTI]

    Butsky, Iryna; Dutton, Aaron A; Wang, Liang; Stinson, Greg S; Penzo, Camilla; Kang, Xi; Keller, Ben W; Wadsley, James

    2015-01-01T23:59:59.000Z

    We show the effect of galaxy formation on the dark matter (DM) distribution across a wide range of halo masses. We focus on how baryon physics changes the dark matter halo shape, the so called "pseudo phase-space density distribution" and the velocity distribution within the virial radius, Rvir and in the solar neighborhood. This study is based on the NIHAO galaxy formation simulations, a large suite of cosmological zoom-in simulations. The galaxies reproduce key properties of observed galaxies, and hence offer unique insight into how baryons change the dark matter morphology and kinematics. When compared to dark matter only simulations, the NIHAO haloes have similar shapes at Rvir, but are substantially rounder inside ~0.1 Rvir. In DM-only simulations the inner halo has a minor-to-major axis ratio of c/a~0.5. In hydro simulations c/a increases with halo mass and integrated star formation efficiency, reaching ~0.8 at the Milky Way mass, reconciling a long-standing conflict between observations and DM only sim...

  4. Applications of Cu{sub 2}O octahedral particles on ITO glass in photocatalytic degradation of dye pollutants under a halogen tungsten lamp

    SciTech Connect (OSTI)

    Zhai, Wei [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Sun, Fengqiang, E-mail: fqsun@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University (China); Exhibition Base of Production, Study and Research on New Polymer Materials and Postgraduate Students’ Innovation Training of Guangdong Higher Education Institutes (China); Chen, Wei; Zhang, Lihe; Min, Zhilin; Li, Weishan [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2013-11-15T23:59:59.000Z

    Graphical abstract: - Highlights: • Photocatalytic activity of Cu{sub 2}O octahedral microcrystals on ITO glass was studied. • They showed high abilities in degradation of methylene blue in the presence of H{sub 2}O{sub 2}. • H{sub 2}O{sub 2} amount could affect the degradation efficiency. • Such particles could be easily recycled and still kept high activity. • Many dye pollutants and their mixtures could be efficiently degraded. - Abstract: Cu{sub 2}O octahedral microcrystals were prepared on the ITO glass by galvanostatic electrodeposition in CuSO{sub 4} solution with poly(vinylpryrrolidone) as the surfactant. By controlling the electrodeposition time, the microcrystals could be randomly distributed on the ITO glass and separated from each other, resulting in as many as possible (1 1 1) crystalline planes were exposed. Such microcrystals immobilized on ITO glass were employed in photodegradation of dye pollutants in the presence of H{sub 2}O{sub 2} under a 150 W halogen tungsten lamp. The photodegradation of methylene blue was taken as an example to evaluate the photocatalytic activities of the octahedral Cu{sub 2}O microcrystals. Effects of electrodeposition time and H{sub 2}O{sub 2} amount on the degradation efficiency was discussed, giving the optimum conditions and the corresponding degradation mechanism. The catalyst showed high ability in degradation of methylene blue, methyl orange, rhodamine B, eosin B and their mixtures under identical conditions.

  5. A MEGACAM SURVEY OF OUTER HALO SATELLITES. II. BLUE STRAGGLERS IN THE LOWEST STELLAR DENSITY SYSTEMS

    SciTech Connect (OSTI)

    Santana, Felipe A.; Munoz, Ricardo R. [Departamento de Astronomia, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile); Geha, Marla [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Cote, Patrick; Stetson, Peter [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC, V9E 2E7 (Canada); Simon, Joshua D. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Djorgovski, S. G., E-mail: fsantana@das.uchile.cl, E-mail: rmunoz@das.uchile.cl [Astronomy Department, California Institute of Technology, Pasadena, CA, 91125 (United States)

    2013-09-10T23:59:59.000Z

    We present a homogeneous study of blue straggler stars across 10 outer halo globular clusters, 3 classical dwarf spheroidal galaxies, and 9 ultra-faint galaxies based on deep and wide-field photometric data taken with MegaCam on the Canada-France-Hawaii Telescope. We find blue straggler stars to be ubiquitous among these Milky Way satellites. Based on these data, we can test the importance of primordial binaries or multiple systems on blue straggler star formation in low-density environments. For the outer halo globular clusters, we find an anti-correlation between the specific frequency of blue stragglers and absolute magnitude, similar to that previously observed for inner halo clusters. When plotted against density and encounter rate, the frequency of blue stragglers is well fit by a single trend with a smooth transition between dwarf galaxies and globular clusters; this result points to a common origin for these satellites' blue stragglers. The fraction of blue stragglers stays constant and high in the low encounter rate regime spanned by our dwarf galaxies, and decreases with density and encounter rate in the range spanned by our globular clusters. We find that young stars can mimic blue stragglers in dwarf galaxies only if their ages are 2.5 {+-} 0.5 Gyr and they represent {approx}1%-7% of the total number of stars, which we deem highly unlikely. These results point to mass-transfer or mergers of primordial binaries or multiple systems as the dominant blue straggler formation mechanism in low-density systems.

  6. The dark matter halos of massive, relaxed galaxy clusters observed with Chandra

    E-Print Network [OSTI]

    R. W. Schmidt; S. W. Allen

    2007-05-09T23:59:59.000Z

    We use the Chandra X-ray Observatory to study the dark matter halos of 34 massive, dynamically relaxed galaxy clusters, spanning the redshift range 0.06halos; for ~80 per cent of the clusters, the NFW model provides a statistically acceptable fit. In contrast, the singular isothermal sphere model can, in almost every case, be completely ruled out. We observe a well-defined mass-concentration relation for the clusters with an intrinsic scatter in good agreement with the predictions from simulations. The slope of the mass-concentration relation, c\\propto M_vir^a/(1+z)^b with a=-0.45\\pm0.12 at 95 per cent confidence, is steeper than the value a~-0.1 predicted by CDM simulations for lower mass halos. With the slope a included as a free fit parameter, the redshift evolution of the concentration parameter, b=0.71\\pm0.52 at 95 per cent confidence, is consistent with the same simulations (b~1). Fixing a~-0.1 leads to an apparent evolution that is significantly slower, b=0.30\\pm0.49, although the goodness of fit in this case is significantly worse. Using a generalized NFW model, we find the inner dark matter density slope, alpha, to be consistent with unity at 95 per cent confidence for the majority of clusters. Combining the results for all clusters for which the generalized NFW model provides a good description of the data, we measure alpha=0.88\\pm0.29 at 95 per cent confidence, in agreement with CDM model predictions.

  7. Explicit computation of shear three-point correlation functions: the one-halo model case

    E-Print Network [OSTI]

    F. Bernardeau

    2005-05-16T23:59:59.000Z

    We present a method for calculating explicit expressions of the shear three-point function for various cosmological models. The method is applied here to the one-halo model in case of power law density profiles for which results are detailed. The three-point functions are found to reproduce to a large extent patterns in the shear correlations obtained in numerical simulations and may serve as a guideline to implement optimized methods for detecting the shear three-point function. In principle, the general method presented here can also be applied for other models of matter correlation.

  8. Massive Compact Halo Objects from the Relics of the Cosmic Quark-Hadron Transition

    E-Print Network [OSTI]

    Shibaji Banerjee; Abhijit Bhattacharyya; Sanjay K. Ghosh; Sibaji Raha. Bikash Sinha; Hiroshi Toki

    2002-11-26T23:59:59.000Z

    The existence of compact gravitational lenses, with masses around 0.5 (M_{\\odot}), has been reported in the halo of the Milky Way. The nature of these dark lenses is as yet obscure, particularly because these objects have masses well above the threshold for nuclear fusion. In this work, we show that they find a natural explanation as being the evolutionary product of the metastable false vacuum domains (the so-called strange quark nuggets) formed in a first order cosmic quark-hadron transition.

  9. Gas around galaxy haloes - II: hydrogen absorption signatures from the environments of galaxies at redshifts 2 < z < 3

    E-Print Network [OSTI]

    Meiksin, A; Tittley, E R

    2015-01-01T23:59:59.000Z

    We compare predictions of large-scale cosmological hydrodynamical simulations for neutral hydrogen absorption signatures in the vicinity of 1e11 - 1e12.5 MSun haloes with observational measurements. Two different hydrodynamical techniques and a variety of prescriptions for gas removal in high density regions are examined. Star formation and wind feedback play only secondary roles in the HI absorption signatures outside the virial radius, but play important roles within. Accordingly, we identify three distinct gaseous regions around a halo: the virialized region, the mesogalactic medium outside the virial radius arising from the extended haloes of galaxies out to about two turnaround radii, and the intergalactic medium beyond. Predictions for the amount of absorption from the mesogalactic and intergalactic media are robust across different methodologies, and the predictions agree with the amount of absorption observed around star-forming galaxies and QSO host galaxies. Recovering the measured amount of absorpt...

  10. Primordial pollution of globular clusters within their host dwarfs embedded in dark matter halos at high redshifts

    E-Print Network [OSTI]

    Kenji Bekki

    2005-12-19T23:59:59.000Z

    Recent observational studies have revealed star-to-star abundance inhomogeneity among light elements (e.g., C, N, O, Na, and Al) of stars on the main sequence in the Galactic globular clusters (GCs). One of promising interpretations for this result is that the observed abundance inhomogeneity is due to the second generation of stars formed from ejecta of the first generation of evolved stars (e.g., AGB stars) within GCs. However it remains unclear whether and how this primordial pollution can occur within GCs. We here propose a new scenario in which primordial pollution of GCs is highly likely to occur if GCs are located in the central regions of high redshift dark matter subhalos that can host low-mass dwarf galaxies. In this scenario, gas ejected from the first generation of stars of GCs can be effectively trapped in the deep gravitational potential of their host halos and consequently can be consumed for the formation of the second generation of stars without losing a significant amount of gas by ram pressure stripping of interstellar and intergalactic medium. During merging of these halos with the proto-Galaxy, the halos are completely destroyed owing to the strong tidal field of the Galaxy. The self-polluted GCs located initially in the central regions of the halos can survive from tidal destruction owing to their compactness and finally become the Galactic halo GCs. In this scenario, ejecta of field stars surrounding the central GCs can be also converted into stars within their host dwarfs and finally become the second generation of stars of GCs. We also discuss the origin of the difference in the degree of abundance inhomogeneity between different GCs, such as $\\omega$ Centauri and NGC 6752, in terms of the difference in physical properties between host halos from which GC originate.

  11. Constraining the extension of a possible gamma-ray halo of 3C 279 from 2008-2014 solar occultations

    E-Print Network [OSTI]

    Kotelnikov, Egor; Troitsky, Sergey

    2014-01-01T23:59:59.000Z

    The angular extension of the gamma-ray image of 3C 279 may be constrained by studying its solar occultations as suggested by Fairbairn et al. (2010). We perform this kind of analysis for seven occultations observed by Fermi-LAT in 2008-2014, using the Fermi-LAT Solar System tools. The results are interpreted in terms of models with extended gamma-ray halo of 3C 279; first constraints on the size and the flux of the halo are reported.

  12. V474 Car: A RARE HALO RS CVn BINARY IN RETROGRADE GALACTIC ORBIT

    SciTech Connect (OSTI)

    Bubar, Eric J.; Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Jensen, Eric L. N. [Swarthmore College, Department of Physics and Astronomy, 500 College Avenue, Swarthmore, PA 19081 (United States); Walter, Frederick M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

    2011-04-15T23:59:59.000Z

    We report the discovery that the star V474 Car is an extremely active, high velocity halo RS CVn system. The star was originally identified as a possible pre-main-sequence star in Carina, given its enhanced stellar activity, rapid rotation (10.3 days), enhanced Li, and absolute magnitude which places it above the main sequence (MS). However, its extreme radial velocity (264 km s{sup -1}) suggested that this system was unlike any previously known pre-MS system. Our detailed spectroscopic analysis of echelle spectra taken with the CTIO 4 m finds that V474 Car is both a spectroscopic binary with an orbital period similar to the photometric rotation period and metal-poor ([Fe/H] {approx_equal}-0.99). The star's Galactic orbit is extremely eccentric (e {approx_equal} 0.93) with a perigalacticon of only {approx}0.3 kpc of the Galactic center-and the eccentricity and smallness of its perigalacticon are surpassed by only {approx}0.05% of local F/G-type field stars. The observed characteristics are consistent with V474 Car being a high-velocity, metal-poor, tidally locked, chromospherically active binary, i.e., a halo RS CVn binary, and one of only a few such specimens known.

  13. Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo

    E-Print Network [OSTI]

    Warren R. Brown; Margaret J. Geller; Scott J. Kenyon; Michael J. Kurtz

    2005-01-11T23:59:59.000Z

    We have discovered a star, SDSS J090745.0+024507, leaving the Galaxy with a heliocentric radial velocity of +853+-12 km/s, the largest velocity ever observed in the Milky Way halo. The star is either a hot blue horizontal branch star or a B9 main sequence star with a heliocentric distance ~55 kpc. Corrected for the solar reflex motion and to the local standard of rest, the Galactic rest-frame velocity is +709 km/s. Because its radial velocity vector points 173.8 deg from the Galactic center, we suggest that this star is the first example of a hyper-velocity star ejected from the Galactic center as predicted by Hills and later discussed by Yu & Tremaine. The star has [Fe/H]~0, consistent with a Galactic center origin, and a travel time of <80 Myr from the Galactic center, consistent with its stellar lifetime. If the star is indeed traveling from the Galactic center, it should have a proper motion of 0.3 mas/yr observable with GAIA. Identifying additional hyper-velocity stars throughout the halo will constrain the production rate history of hyper-velocity stars at the Galactic center.

  14. Beryllium in the Ultra-Lithium-Deficient,Metal-Poor Halo Dwarf, G186-26

    E-Print Network [OSTI]

    Ann Merchant Boesgaard; Megan C. Novicki

    2005-09-16T23:59:59.000Z

    The vast majority of low-metal halo dwarfs show a similar amount of Li; this has been attributed to the Li that was produced in the Big Bang. However, there are nine known halo stars with T $>$ 5900 K and [Fe/H] $<$ $-$1.0 that are ultra-Li-deficient. We have looked for Be in the very low metallicity star, G 186-26 at [Fe/H] = $-$2.71, which is one of the ultra-Li-deficient stars. This star is also ultra-Be deficient. Relative to Be in the Li-normal stars at [Fe/H] = $-$2.7, G 182-26 is down in Be by more than 0.8 dex. Of two potential causes for the Li-deficiency -- mass-transfer in a pre-blue straggler or extra rotationally-induced mixing in a star that was initially a very rapid rotator -- the absence of Be favors the blue-straggler hypothesis, but the rotation model cannot be ruled-out completely.

  15. On the possible environmental effect in distributing heavy elements beyond individual gaseous halos

    E-Print Network [OSTI]

    Johnson, Sean D; Mulchaey, John S

    2015-01-01T23:59:59.000Z

    We present a study of extended galaxy halo gas through HI and OVI absorption over two decades in projected distance at $z\\approx0.2$. The study is based on a sample of $95$ galaxies from a highly complete ($ > 80\\%$) survey of faint galaxies ($L > 0.1L_*$) with archival quasar absorption spectra and $53$ galaxies from the literature. A clear anti-correlation is found between HI (OVI) column density and virial radius normalized projected distance, $d/R_{\\rm h}$. Strong HI (OVI) absorption systems with column densities greater than $10^{14.0}$ ($10^{13.5}$) cm$^{-2}$ are found for $48$ of $54$ ($36$ of $42$) galaxies at $d R_{\\rm h}$ compared to isolated galaxies ($\\kappa_{\\rm OVI}\\approx0.13$ versus $0.04$) but no excess HI absorption. These findings suggest that environmental effects play a role in distributing heavy elements beyond the enriched gaseous halos of individual galaxies. Finally, we find that differential HI and OVI absorption between early- and late-type galaxies continues from $d < R_{\\rm h}$...

  16. Glow in the Dark Matter: Observing galactic halos with scattered light

    E-Print Network [OSTI]

    Jonathan H. Davis; Joseph Silk

    2015-02-04T23:59:59.000Z

    We consider the observation of diffuse halos of light around the discs of spiral galaxies, as a probe of the interaction cross section between Dark Matter and photons. Using the galaxy M101 as an example, we show that for a scattering cross section at the level of 10^(-23) x (m/GeV) cm^2 or greater Dark Matter in the halo will scatter light out from the more luminous centre of the disc to larger radii, contributing to an effective increased surface brightness at the edges of the observed area on the sky. This allows us to set an upper limit on the DM-photon cross section using data from the Dragonfly instrument. We then show how to improve this constraint, and the potential for discovery, by combining the radial profile of DM-photon scattering with measurements at multiple wavelengths. Observation of diffuse light presents a new and potentially powerful way to probe the interactions of Dark Matter with photons, which is complimentary to existing searches.

  17. A confirmed location in the Galactic halo for the high-velocity cloud 'chain A'

    E-Print Network [OSTI]

    Hugo van Woerden; Ulrich J. Schwarz; Reynier F. Peletier; Bart P. Wakker; Peter M. W. Kalberla

    1999-07-08T23:59:59.000Z

    The high-velocity clouds of atomic hydrogen, discovered about 35 years ago, have velocities inconsistent with simple Galactic rotation models that generally fit the stars and gas in the Milky Way disk. Their origins and role in Galactic evolution remain poorly understood, largely for lack of information on their distances. The high-velocity clouds might result from gas blown from the Milky Way disk into the halo by supernovae, in which case they would enrich the Galaxy with heavy elements as they fall back onto the disk. Alternatively, they may consist of metal-poor gas -- remnants of the era of galaxy formation, accreted by the Galaxy and reducing its metal abundance. Or they might be truly extragalactic objects in the Local Group of galaxies. Here we report a firm distance bracket for a large high-velocity cloud, Chain A, which places it in the Milky Way halo (2.5 to 7 kiloparsecs above the Galactic plane), rather than at an extragalactic distance, and constrains its gas mass to between 10^5 and 2 times 10^6 solar masses.

  18. A confirmed location in the Galactic halo for the high-velocity cloud "chain A"

    E-Print Network [OSTI]

    Van Woerden, H; Peletier, R F; Wakker, B P; Kalberla, P M W; Woerden, Hugo van; Schwarz, Ulrich J.; Peletier, Reynier F.; Wakker, Bart P.; Kalberla, Peter M.W.

    1999-01-01T23:59:59.000Z

    The high-velocity clouds of atomic hydrogen, discovered about 35 years ago, have velocities inconsistent with simple Galactic rotation models that generally fit the stars and gas in the Milky Way disk. Their origins and role in Galactic evolution remain poorly understood, largely for lack of information on their distances. The high-velocity clouds might result from gas blown from the Milky Way disk into the halo by supernovae, in which case they would enrich the Galaxy with heavy elements as they fall back onto the disk. Alternatively, they may consist of metal-poor gas -- remnants of the era of galaxy formation, accreted by the Galaxy and reducing its metal abundance. Or they might be truly extragalactic objects in the Local Group of galaxies. Here we report a firm distance bracket for a large high-velocity cloud, Chain A, which places it in the Milky Way halo (2.5 to 7 kiloparsecs above the Galactic plane), rather than at an extragalactic distance, and constrains its gas mass to between 10^5 and 2 times 10^...

  19. On the Diffuse Lyman-alpha Halo Around Lyman-alpha Emitting Galaxies

    E-Print Network [OSTI]

    Lake, Ethan; Cen, Renyue; Sadoun, Raphael; Momose, Rieko; Ouchi, Masami

    2015-01-01T23:59:59.000Z

    Ly$\\alpha$ photons scattered by neutral hydrogen atoms in the circumgalactic media or produced in the halos of star-forming galaxies are expected to lead to extended Ly$\\alpha$ emission around galaxies. Such low surface brightness Ly$\\alpha$ halos (LAHs) have been detected by stacking Ly$\\alpha$ images of high-redshift star-forming galaxies. We study the origin of LAHs by performing radiative transfer modeling of nine $z=3.1$ Lyman-Alpha Emitters (LAEs) in a high resolution hydrodynamic galaxy formation simulation. We develop a method of computing the mean Ly$\\alpha$ surface brightness profile of each LAE by effectively integrating over many different observing directions. Without adjusting any parameters, our model yields an average Ly$\\alpha$ surface brightness profile in remarkable agreement with observations. We find that observed LAHs can not be accounted for solely by photons originating from the central LAE and scattered to large radii by hydrogen atoms in the circumgalactic gas. Instead, Ly$\\alpha$ em...

  20. The self-enrichment of galactic halo globular clusters : a clue to their formation ?

    E-Print Network [OSTI]

    G. Parmentier; E. Jehin; P. Magain; C. Neuforge; A. Noels; A. A. Thoul

    1999-11-15T23:59:59.000Z

    We present a model of globular cluster self-enrichment. In the protogalaxy, cold and dense clouds embedded in the hot protogalactic medium are assumed to be the progenitors of galactic halo globular clusters. The massive stars of a first generation of metal-free stars, born in the central areas of the proto-globular cluster clouds, explode as Type II supernovae. The associated blast waves trigger the expansion of a supershell, sweeping all the material of the cloud, and the heavy elements released by these massive stars enrich the supershell. A second generation of stars is born in these compressed and enriched layers of gas. These stars can recollapse and form a globular cluster. This work aims at revising the most often encountered argument against self-enrichment, namely the presumed ability of a small number of supernovae to disrupt a proto-globular cluster cloud. We describe a model of the dynamics of the supershell and of its progressive chemical enrichment. We show that the minimal mass of the primordial cluster cloud required to avoid disruption by several tens of Type II supernovae is compatible with the masses usually assumed for proto-globular cluster clouds. Furthermore, the corresponding self-enrichment level is in agreement with halo globular cluster metallicities.

  1. Investigation of the novel attributes of a single-halo double gate SOI MOSFET: 2D simulation study

    E-Print Network [OSTI]

    Kumar, M. Jagadesh

    of single halo to the double gate structure results in threshold voltage roll-up, reduced DIBL, high drain the drain voltage variations. This work illustrates the benefits of high performance DG-SH SOI MOS devices gate pþ poly and back gate nþ poly) are becoming popular since this type of structure provides

  2. GALAXY HALO TRUNCATION AND GIANT ARC SURFACE BRIGHTNESS RECONSTRUCTION IN THE CLUSTER MACSJ1206.2-0847

    SciTech Connect (OSTI)

    Eichner, Thomas; Seitz, Stella; Monna, Anna [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Suyu, Sherry H. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Halkola, Aleksi [Institute of Medical Engineering, University of Luebeck, Ratzeburger Allee 160 23562 Luebeck (Germany); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, Adi [Institut fuer Theoretische Astrophysik, ZAH, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Coe, Dan; Postman, Marc; Koekemoer, Anton; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Rosati, Piero [ESO-European Southern Observatory, D-85748 Garching bei Muenchen (Germany); Grillo, Claudio; Host, Ole [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Balestra, Italo [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zheng, Wei; Lemze, Doron [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Molino, Alberto [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada E-18008 (Spain); and others

    2013-09-10T23:59:59.000Z

    In this work, we analyze the mass distribution of MACSJ1206.2-0847, particularly focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has a significant amount of intracluster light that is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the overall relaxed state. The cluster lenses 12 background galaxies into multiple images and one galaxy at z = 1.033 into a giant arc and its counterimage. The multiple image positions and the surface brightness (SFB) distribution of the arc, which is bent around several cluster members, are sensitive to the cluster galaxy halo properties. We model the cluster mass distribution with a Navarro-Frenk-White profile and the galaxy halos with two parameters for the mass normalization and the extent of a reference halo assuming scalings with their observed near-infrared light. We match the multiple image positions at an rms level of 0.''85 and can reconstruct the SFB distribution of the arc in several filters to a remarkable accuracy based on this cluster model. The length scale where the enclosed galaxy halo mass is best constrained is about 5 effective radii-a scale in between those accessible to dynamical and field strong-lensing mass estimates on the one hand and galaxy-galaxy weak-lensing results on the other hand. The velocity dispersion and halo size of a galaxy with m{sub 160W,AB} = 19.2 and M{sub B,Vega} = -20.7 are {sigma} = 150 km s{sup -1} and r Almost-Equal-To 26 {+-} 6 kpc, respectively, indicating that the halos of the cluster galaxies are tidally stripped. We also reconstruct the unlensed source, which is smaller by a factor of {approx}5.8 in area, demonstrating the increase in morphological information due to lensing. We conclude that this galaxy likely has star-forming spiral arms with a red (older) central component.

  3. Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds

    E-Print Network [OSTI]

    P. Tisserand; L. Le Guillou; C. Afonso; J. N. Albert; J. Andersen; R. Ansari; E. Aubourg; P. Bareyre; J. P. Beaulieu; X. Charlot; C. Coutures; R. Ferlet; P. Fouqué; J. F. Glicenstein; B. Goldman; A. Gould; D. Graff; M. Gros; J. Haissinski; C. Hamadache; J. de Kat; T. Lasserre; E. Lesquoy; C. Loup; C. Magneville; J. B. Marquette; E. Maurice; A. Maury; A. Milsztajn; M. Moniez; N. Palanque-Delabrouille; O. Perdereau; Y. R. Rahal; J. Rich; M. Spiro; A. Vidal-Madjar; L. Vigroux; S. Zylberajch

    2007-04-19T23:59:59.000Z

    The EROS-2 project was designed to test the hypothesis that massive compact halo objects (the so-called ``machos'') could be a major component of the dark matter halo of the Milky Way galaxy. To this end, EROS-2 monitored over 6.7 years $33\\times10^6$ stars in the Magellanic clouds for microlensing events caused by such objects. In this work, we use only a subsample of $7\\times10^6$ bright stars spread over $84 \\deg^2$ of the LMC and $9 \\deg^2$ of the SMC. The strategy of using only bright stars helps to discriminate against background events due to variable stars and allows a simple determination of the effects of source confusion (blending). The use of a large solid angle makes the survey relatively insensitive to effects that could make the optical depth strongly direction dependent. Using this sample of bright stars, only one candidate event was found, whereas $\\sim39$ events would have been expected if the Halo were entirely populated by objects of mass $M\\sim0.4M_{\\odot}$. Combined with the results of EROS-1, this implies that the optical depth toward the Large Magellanic Cloud (\\object{LMC}) due to such lenses is $\\tau<0.36\\times10^{-7}$ (95%CL), corresponding to a fraction of the halo mass of less than 8%. This optical depth is considerably less than that measured by the MACHO collaboration in the central region of the LMC. More generally, machos in the mass range $0.6\\times10^{-7}M_\\odotHalo.

  4. Ultra-High Energy Cosmic Rays and Neutron-Decay Halos from Gamma Ray Bursts

    E-Print Network [OSTI]

    C. D. Dermer

    2001-03-20T23:59:59.000Z

    Simple arguments concerning power and acceleration efficiency show that ultra-high energy cosmic rays (UHECRS) with energies >~ 10^{19} eV could originate from GRBs. Neutrons formed through photo-pion production processes in GRB blast waves leave the acceleration site and travel through intergalactic space, where they decay and inject a very energetic proton and electron component into intergalactic space. The neutron-decay protons form a component of the UHECRs, whereas the neutron-decay electrons produce optical/X-ray synchrotron and gamma radiation from Compton-scattered background radiation. A significant fraction of galaxies with GRB activity should be surrounded by neutron-decay halos of characteristic size ~ 100 kpc.

  5. Fusion reactions with the one-neutron halo nucleus 15C

    E-Print Network [OSTI]

    M. Alcorta; K. E. Rehm; B. B. Back; S. Bedoor; P. F. Bertone; C. M. Deibel; B. DiGiovine; H. Esbensen; J. P. Greene; C. R. Hoffmann; C. L. Jiang; J. C. Lighthall; S. T. Marley; R. C. Pardo; M. Paul; A. M. Rogers; C. Ugalde; A. H. Wuosmaa

    2011-04-06T23:59:59.000Z

    The structure of 15C, with an s1/2 neutron weakly bound to a closed-neutron shell nucleus 14C, makes it a prime candidate for a one-neutron halo nucleus. We have for the first time studied the cross section for the fusion-fission reaction 15C + 232Th at energies in the vicinity of the Coulomb barrier and compared it to the yield of the neighboring 14C + 232Th system measured in the same experiment. At sub-barrier energies, an enhancement of the fusion yield by factors of 2-5 was observed for 15C, while the cross sections for 14C match the trends measured for 12,13C.

  6. The small scale dynamo and the amplification of magnetic fields in massive primordial haloes

    E-Print Network [OSTI]

    Latif, M A; Schmidt, W; Niemeyer, J

    2012-01-01T23:59:59.000Z

    While our present standard model of cosmology yields no clear prediction for the initial magnetic field strength, efficient dynamo action may compensate for initially weak seed fields via rapid amplification. In particular, the small-scale dynamo is expected to exponentially amplify any weak magnetic field in the presence of turbulence. We explore whether this scenario is viable using cosmological magneto-hydrodynamics simulations modeling the formation of the first galaxies, which are expected to form in so-called atomic cooling halos with virial temperatures $\\rm T_{vir} \\geq 10^{4}$ K. As previous calculations have shown that a high Jeans resolution is needed to resolve turbulent structures and dynamo effects, our calculations employ resolutions of up to 128 cells per Jeans length. The presence of the dynamo can be clearly confirmed for resolutions of at least 64 cells per Jeans length, while saturation occurs at approximate equipartition with turbulent energy. As a result of the large Reynolds numbers in ...

  7. Prediction Space Weather Using an Asymmetric Cone Model for Halo CMEs

    E-Print Network [OSTI]

    G. Michalek; N. Gopalswamy; S. Yashiro

    2007-10-24T23:59:59.000Z

    Halo coronal mass ejections (HCMEs) are responsible of the most severe geomagnetic storms. A prediction of their geoeffectiveness and travel time to Earth's vicinity is crucial to forecast space weather. Unfortunately coronagraphic observations are subjected to projection effects and do not provide true characteristics of CMEs. Recently, Michalek (2006, {\\it Solar Phys.}, {\\bf237}, 101) developed an asymmetric cone model to obtain the space speed, width and source location of HCMEs. We applied this technique to obtain the parameters of all front-sided HCMEs observed by the SOHO/LASCO experiment during a period from the beginning of 2001 until the end of 2002 (solar cycle 23). These parameters were applied for the space weather forecast. Our study determined that the space speeds are strongly correlated with the travel times of HCMEs within Earth's vicinity and with the magnitudes related to geomagnetic disturbances.

  8. Cool carbon stars in the halo II. A study of 25 new objects

    E-Print Network [OSTI]

    N. Mauron; T. R. Kendall; K. Gigoyan

    2005-06-22T23:59:59.000Z

    We present new results from an ongoing survey of carbon-rich asymptotic giant (AGB) stars in the halo of our Galaxy. After selecting candidates primarily through their 2MASS colours, slit spectroscopy was achieved at the ESO NTT telescope. Twenty-one new AGB carbon stars were discovered, increasing the total of presently known similar AGB C stars to about 120. A further four were observed again in order to confirm their carbon-rich nature and measure radial velocities. Two main findings emerge from this work. First, we found a C star located at about 130 kpc from the Sun and at b = -62 degrees. This distant star is remarkably close (5 kpc) to the principal plane of the Stream of the Sagittarius dwarf galaxy, and is likely to be a tracer of a distant poorly populated southern warp of the Stream. etc etc

  9. Detecting dark matter-dark energy coupling with the halo mass function

    E-Print Network [OSTI]

    P. M. Sutter; P. M. Ricker

    2008-10-03T23:59:59.000Z

    We use high-resolution simulations of large-scale structure formation to analyze the effects of interacting dark matter and dark energy on the evolution of the halo mass function. Using a chi-square likelihood analysis, we find significant differences in the mass function between models of coupled dark matter-dark energy and standard concordance cosmology Lambda-CDM out to redshift z=1.5. We also find a preliminary indication that the Dark Energy Survey should be able to distinguish these models from Lambda-CDM within its mass and redshift contraints. While we can distinguish the effects of these models from Lambda-CDM cosmologies with different fundamental parameters, DES will require independent measurements of sigma-8 to confirm these effects.

  10. The large-scale structure of the halo of the Andromeda Galaxy Part I: global stellar density, morphology and metallicity properties

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    We present an analysis of the large-scale structure of the halo of the Andromeda galaxy, based on the Pan-Andromeda Archeological Survey (PAndAS), currently the most complete map of resolved stellar populations in any galactic halo. Despite copious substructure, the global halo populations follow closely power law profiles that become steeper with increasing metallicity. We divide the sample into stream-like populations and a smooth halo component. Fitting a three-dimensional halo model reveals that the most metal-poor populations ([Fe/H]-0.6). The space density of the smooth metal-poor component has a global power-law slope of -3.08+/-0.07, and a non-parametric fit shows that the slope remains nearly constant from 30kpc to 300kpc. The total stellar mass in the halo at distances beyond 2 degrees is 1.1x10^10 Solar masses, while that of the smooth component is 3x10^9 Solar masses. Extrapolating into the inner galaxy, the total stellar mass of the smooth halo is plausibly 8x10^9 Solar masses. We detect a substa...

  11. Application of Hydrogen Assisted Lean Operation to Natural Gas-Fueled Reciprocating Engines (HALO)

    SciTech Connect (OSTI)

    Chad Smutzer

    2006-01-01T23:59:59.000Z

    Two key challenges facing Natural Gas Engines used for cogeneration purposes are spark plug life and high NOx emissions. Using Hydrogen Assisted Lean Operation (HALO), these two keys issues are simultaneously addressed. HALO operation, as demonstrated in this project, allows stable engine operation to be achieved at ultra-lean (relative air/fuel ratios of 2) conditions, which virtually eliminates NOx production. NOx values of 10 ppm (0.07 g/bhp-hr NO) for 8% (LHV H2/LHV CH4) supplementation at an exhaust O2 level of 10% were demonstrated, which is a 98% NOx emissions reduction compared to the leanest unsupplemented operating condition. Spark ignition energy reduction (which will increase ignition system life) was carried out at an oxygen level of 9%, leading to a NOx emission level of 28 ppm (0.13 g/bhp-hr NO). The spark ignition energy reduction testing found that spark energy could be reduced 22% (from 151 mJ supplied to the coil) with 13% (LHV H2/LHV CH4) hydrogen supplementation, and even further reduced 27% with 17% hydrogen supplementation, with no reportable effect on NOx emissions for these conditions and with stable engine torque output. Another important result is that the combustion duration was shown to be only a function of hydrogen supplementation, not a function of ignition energy (until the ignitability limit was reached). The next logical step leading from these promising results is to see how much the spark energy reduction translates into increase in spark plug life, which may be accomplished by durability testing.

  12. TURBULENCE AND RADIO MINI-HALOS IN THE SLOSHING CORES OF GALAXY CLUSTERS

    SciTech Connect (OSTI)

    ZuHone, J. A.; Markevitch, M. [Astrophysics Science Division, Laboratory for High Energy Astrophysics, Code 662, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Astrophysics Science Division, Laboratory for High Energy Astrophysics, Code 662, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brunetti, G. [INAF Istituto di Radioastronomia, Via Gobetti 101, I-40129 Bologna (Italy)] [INAF Istituto di Radioastronomia, Via Gobetti 101, I-40129 Bologna (Italy); Giacintucci, S. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)] [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

    2013-01-10T23:59:59.000Z

    A number of relaxed, cool-core galaxy clusters exhibit diffuse, steep-spectrum radio sources in their central regions, known as radio mini-halos. It has been proposed that the relativistic electrons responsible for the emission have been reaccelerated by turbulence generated by the sloshing of the cool core gas. We present a high-resolution MHD simulation of gas sloshing in a galaxy cluster coupled with subgrid simulations of relativistic electron acceleration to test this hypothesis. Our simulation shows that the sloshing motions generate turbulence on the order of {delta}v {approx} 50-200 km s{sup -1} on spatial scales of {approx}50-100 kpc and below in the cool core region within the envelope of the sloshing cold fronts, whereas outside the cold fronts, there is negligible turbulence. This turbulence is potentially strong enough to reaccelerate relativistic electron seeds (with initial {gamma} {approx} 100-500) to {gamma} {approx} 10{sup 4} via damping of magnetosonic waves and non-resonant compression. The seed electrons could remain in the cluster from, e.g., past active galactic nucleus activity. In combination with the magnetic field amplification in the core, these electrons then produce diffuse radio synchrotron emission that is coincident with the region bounded by the sloshing cold fronts, as indeed observed in X-rays and the radio. The result holds for different initial spatial distributions of pre-existing relativistic electrons. The power and the steep spectral index ({alpha} Almost-Equal-To 1-2) of the resulting radio emission are consistent with observations of mini-halos, though the theoretical uncertainties of the acceleration mechanisms are high. We also produce simulated maps of inverse-Compton hard X-ray emission from the same population of relativistic electrons.

  13. Beryllium in Ultra-Lithium-Deficient Halo Stars - The Blue Straggler Connection

    E-Print Network [OSTI]

    Ann Merchant Boesgaard

    2007-05-10T23:59:59.000Z

    There are nine metal-deficient stars that have Li abundances well below the Li plateau that is defined by over 100 unevolved stars with temperatures above 5800 K and values of [Fe/H] $<$ $-$1.0. Abundances of Be have been determined for most of these ultra-Li-deficient stars in order to investigate the cause of the Li deficiencies. High-resolution and high signal-to-noise spectra have been obtained in the Be II spectral region near 3130 \\AA for six ultra-Li-deficient stars with the Keck I telescope and its new uv-sensitive CCD on the upgraded HIRES. The spectrum synthesis technique has been used to determine Be abundances. All six stars are found to have Be deficiencies also. Two have measurable - but reduced - Be and four have only upper limits on Be. These results are consistent with the idea that these Li- and Be-deficient stars are analogous to blue stragglers. The stars have undergone mass transfer events (or mergers) which destroy or dilute both Li and Be. The findings cannot be matched by the models that predict that the deficiencies are due to extra-mixing in a subset of halo stars that were initially rapid rotators, with the possible exception of one star, G 139-8. Because the ultra-Li-deficient stars are also Be-deficient, they appear to be genuine outliers in population of halo stars used to determine the value of primordial Li; they no longer have the Li in their atmospheres that was produced in the Big Bang.

  14. THE COS-HALOS SURVEY: KECK LRIS AND MAGELLAN MagE OPTICAL SPECTROSCOPY

    SciTech Connect (OSTI)

    Werk, Jessica K.; Prochaska, J. Xavier [UCO/Lick Observatory, University of California, Santa Cruz, CA (United States); Thom, Christopher; Tumlinson, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD (United States); Tripp, Todd M.; Meiring, Joseph D. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); O'Meara, John M., E-mail: jwerk@ucolick.org [Department of Chemistry and Physics, Saint Michael's College, Colchester, VT (United States)

    2012-01-01T23:59:59.000Z

    We present high signal-to-noise optical spectra for 67 low-redshift (0.1 < z < 0.4) galaxies that lie within close projected distances (5 kpc < {rho} < 150 kpc) of 38 background UV-bright QSOs. The Keck LRIS and Magellan MagE data presented here are part of a survey that aims to construct a statistically sampled map of the physical state and metallicity of gaseous galaxy halos using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope. We provide a detailed description of the optical data reduction and subsequent spectral analysis that allow us to derive the physical properties of this uniquely data-rich sample of galaxies. The galaxy sample is divided into 38 pre-selected L {approx} L*, z {approx} 0.2 'target' galaxies and 29 'bonus' galaxies that lie in close proximity to the QSO sightlines. We report galaxy spectroscopic redshifts accurate to {+-}30 km s{sup -1}, impact parameters, rest-frame colors, stellar masses, total star formation rates (SFRs), and gas-phase interstellar medium oxygen abundances. When we compare the distribution of these galaxy characteristics to those of the general low-redshift population, we find good agreement. The L {approx} L* galaxies in this sample span a diverse range of color (1.0 < u - r < 3.0), stellar mass (10{sup 9.5} < M/M{sub Sun} < 10{sup 11.5}), and SFRs (0.01-20 M{sub Sun} yr{sup -1}). These optical data, along with the COS UV spectroscopy, comprise the backbone of our efforts to understand how halo gas properties may correlate with their host galaxy properties, and ultimately to uncover the processes that drive gas outflow and/or are influenced by gas inflow.

  15. Collisions induced by halo and weakly bound nuclei around the Coulomb barrier: Results at INFN-LNS Catania

    SciTech Connect (OSTI)

    Figuera, Pierpaolo [INFN Laboratorio Nazionale del Sud, Via S.Sofia 62, I95123 Catania (Italy)

    2012-10-20T23:59:59.000Z

    The study of collisions around the Coulomb barrier induced by halo and/or weakly bound nuclei has been the object of many publications in the last years, since the peculiar structure of such nuclei can strongly affect the reaction dynamics. In this paper we will summarize some results on the above topic obtained by our group at INFN-LNS Catania. Results concerning the study of elastic scattering and different reaction mechanisms in collisions induced by the halo nuclei {sup 11}Be and {sup 6}He and by the weakly bound stable nuclei {sup 6,7}Li on a {sup 64}Zn target, at energies around the Coulomb barrier, will be presented. The conclusions of our studies will be compared with the ones of other authors, in order to show if clear systematic conclusions can be drawn from the different papers published in the literature so far.

  16. The Role of Primary 16O as a Neutron Poison in AGB stars and Fluorine primary production at Halo Metallicities

    E-Print Network [OSTI]

    Gallino, R; Cristallo, S; Straniero, O

    2010-01-01T23:59:59.000Z

    The discovery of a historical bug in the s-post-process AGB code obtained so far by the Torino group forced us to reconsider the role of primary 16O in the 13C-pocket, produced by the 13C(a, n)16O reaction, as important neutron poison for the build up of the s-elements at Halo metallicities. The effect is noticeable only for the highest 13C-pocket efficiencies (cases ST*2 and ST). For Galactic disc metallicities, the bug effect is negligible. A comparative analysis of the neutron poison effect of other primary isotopes (12C, 22Ne and its progenies) is presented. The effect of proton captures, by 14N(n, p)14C, boosts a primary production of Fluorine in Halo AGB stars, with [F/Fe] comparable to [C/Fe], without affecting the s-elements production.

  17. Recent developments in Tropospheric Halogen

    E-Print Network [OSTI]

    von Glasow, Roland

    that have been published in the last few years. Platt and Hönninger (2003) and von Glasow and Crutzen (2007 these ODEs were linked to the presence of bromine compounds (Barrie et al. 1988) and Hausmann and Platt (1994 termed the "bromine explosion" (Platt and Janssen, 1995). Mercury depletion events in the Arctic were

  18. Chemical Evolution of the Galactic Halo through Supernova-Induced Star Formation and Its Implication for Population III Stars

    E-Print Network [OSTI]

    Takuji Tsujimoto; Toshikazu Shigeyama; Yuzuru Yoshii

    1999-05-06T23:59:59.000Z

    A model for Galactic chemical evolution, driven by supernova-induced star formation, is formulated and used to examine the nature of the Galactic halo at early epochs. In this model, new stars are formed following each supernova event, thus their abundance pattern is determined by the combination of heavy elements ejected from the supernova itself and those elements which are already present in the interstellar gas swept up by the supernova remnant. The end result is a prediction of large scatter in the abundance ratios among low-metallicity stars, reflecting a different nucleosynthesis yield for each Type II supernova with a different progenitor mass. Formation of new stars is terminated when supernova remnants sweep up too little gas to form shells. We show from calculations based on the above scenario that (i) the observed [Fe/H] distribution for the Galactic halo field stars can be reproduced without effectively decreasing the heavy-element yields from Type II supernovae by some manipulation required by previous models (e.g., via mass loss from the early Galaxy, or later mixing with ``pristine'' hydrogen clouds), (ii) the large observed scatter in the abundance ratio [Eu/Fe] for the most metal-poor stars can also be reproduced, and (iii) the frequency distribution of stars in the [Eu/Fe]-[Fe/H] plane can be predicted. Our model suggests that the probability of identifying essentially metal-free stars (Population III) in the local halo is around one in 10^{3-4}, provided that star formation in the halo is confined to individual gas clouds with mass of 10^{6-7} Msun and that the initial mass function of metal-free stars is not significantly different from the Salpeter mass function.

  19. Nuclear Charge Radii of 7;9;10 Be and the One-Neutron Halo Nucleus 11

    E-Print Network [OSTI]

    Pfeifer, Holger

    with predictions of ab initio nuclear-structure calculations we find good agreement. Additionally, the nuclearNuclear Charge Radii of 7;9;10 Be and the One-Neutron Halo Nucleus 11 Be W. No¨rtersha¨user,1,2 D, Canada E3B 5A3 (Received 6 September 2008; published 13 February 2009) Nuclear charge radii of 7

  20. Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds

    E-Print Network [OSTI]

    Tisserand, P; Afonso, C; Albert, J N; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Beaulieu, J P; Charlot, X; Coutures, C; Ferlet, R; Fouqué, P; Glicenstein, J F; Goldman, B; Gould, A; Graff, D; Gros, M; Haïssinski, J; Hamadache, C; De Kat, J; Lasserre, T; Lesquoy, E; Loup, C; Magneville, C; Marquette, J B; Maurice, E; Maury, A; Milsztajn, A; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Rahal, Y R; Rich, J; Spiro, M; Vidal-Madjar, A; Vigroux, L; Zylberajch, S

    2006-01-01T23:59:59.000Z

    The EROS-2 project was designed to test the hypothesis that massive compact halo objects (the so-called ``machos'') could be a major component of the dark matter halo of the Milky Way galaxy. To this end, EROS-2 monitored millions of stars in the Magellanic clouds for microlensing events caused by such objects. About $33\\times10^6$ Magellanic stars were observed over a period of 6.7 years. Unlike all previous studies of Magellanic microlensing, we use only a subsample of $7\\times10^6$ bright stars. This strategy minimizes backgrounds due to variable stars and ensures accurate determination of lensing parameters by minimizing source confusion (blending). Using this sample of bright stars, only one candidate event was found, whereas $\\sim42$ events would have been expected if the Halo were entirely populated by objects of mass $M\\sim0.4M_{\\odot}$. Combined with the results of EROS-1, this implies that the optical depth toward the Large Magellanic Cloud (\\object{LMC}) due to such lenses is $\\tau<0.36\\times10^...

  1. The Spatial Clustering of ROSAT All-Sky Survey AGNs II. Halo Occupation Distribution Modeling of the Cross Correlation Function

    E-Print Network [OSTI]

    Miyaji, Takamitsu; Coil, Alison L; Aceves, Hector

    2010-01-01T23:59:59.000Z

    This is the second paper of a series that reports on our investigation of the clustering properties of AGNs in the ROSAT All-Sky Survey (RASS) through cross-correlation functions (CCFs) with Sloan Digital Sky Survey (SDSS) galaxies. In this paper, we apply the Halo Occupation Distribution (HOD) model to the CCFs between the RASS Broad-line AGNs with SDSS Luminous Red Galaxies (LRGs) in the redshift range 0.16halo mass, M_h, and model the full distribution function of AGN host dark matter halos. In addition, we are able to determine the large-scale bias and the mean M_h more accurately. We explore the behavior of three simple HOD models. Our first model (Model A) is a truncated power-law HOD model in which all AGNs are satellites. With this model, we find an upper lim...

  2. Quantifying the heart of darkness with GHALO - a multi-billion particle simulation of our galactic halo

    E-Print Network [OSTI]

    Joachim Stadel; Doug Potter; Ben Moore; Jürg Diemand; Piero Madau; Marcel Zemp; Michael Kuhlen; Vicent Quilis

    2008-08-22T23:59:59.000Z

    We perform a series of simulations of a Galactic mass dark matter halo at different resolutions, our largest uses over three billion particles and has a mass resolution of 1000 M_sun. We quantify the structural properties of the inner dark matter distribution and study how they depend on numerical resolution. We can measure the density profile to a distance of 120 pc (0.05% of R_vir) where the logarithmic slope is -0.8 and -1.4 at (0.5% of R_vir). We propose a new two parameter fitting function that has a linearly varying logarithmic density gradient which fits the GHALO and VL2 density profiles extremely well. Convergence in the density profile and the halo shape scales as N^(-1/3), but the shape converges at a radius three times larger at which point the halo becomes more spherical due to numerical resolution. The six dimensional phase-space profile is dominated by the presence of the substructures and does not follow a power law, except in the smooth under-resolved inner few kpc.

  3. The accretion history of dark matter halos III: A physical model for the concentration-mass relation

    E-Print Network [OSTI]

    Correa, Camila A; Schaye, Joop; Duffy, Alan R

    2015-01-01T23:59:59.000Z

    We present a semi-analytic, physically motivated model for dark matter halo concentration as a function of halo mass and redshift. The semi-analytic model is intimately based on hierarchical structure formation. It uses an analytic model for the halo mass accretion history, based on extended Press Schechter (EPS) theory, and an empirical relation between concentration and an appropriate definition of formation time obtained through fits to the results of numerical simulations. The resulting concentration-mass relations are tested against the simulations and do not exhibit an upturn at high masses or high redshifts as claimed by recent works. Because our semi-analytic model is based on EPS theory, it can be applied to wide ranges in mass, redshift and cosmology. We predict a change of slope in the z=0 concentration-mass relation at a mass scale of $10^{11}\\rm{M}_{\\odot}$, that is caused by the varying power in the density perturbations. We provide best-fitting expressions of the $c-M$ relations as well as nume...

  4. The neutrino signal at HALO: learning about the primary supernova neutrino fluxes and neutrino properties

    SciTech Connect (OSTI)

    Väänänen, Daavid; Volpe, Cristina, E-mail: vaananen@ipno.in2p3.fr, E-mail: volpe@ipno.in2p3.fr [Institut de Physique Nucléaire, F-91406 Orsay cedex, CNRS/IN2P3 and University of Paris-XI (France)

    2011-10-01T23:59:59.000Z

    Core-collapse supernova neutrinos undergo a variety of phenomena when they travel from the high neutrino density region and large matter densities to the Earth. We perform analytical calculations of the supernova neutrino fluxes including collective effects due to the neutrino-neutrino interactions, the Mikheev-Smirnov-Wolfenstein (MSW) effect due to the neutrino interactions with the background matter and decoherence of the wave packets as they propagate in space. We predict the numbers of one- and two-neutron charged and neutral-current electron-neutrino scattering on lead events. We show that, due to the energy thresholds, the ratios of one- to two-neutron events are sensitive to the pinching parameters of neutrino fluxes at the neutrinosphere, almost independently of the presently unknown neutrino properties. Besides, such events have an interesting sensitivity to the spectral split features that depend upon the presence/absence of energy equipartition among neutrino flavors. Our calculations show that a lead-based observatory like the Helium And Lead Observatory (HALO) has the potential to pin down important characteristics of the neutrino fluxes at the neutrinosphere, and provide us with information on the neutrino transport in the supernova core.

  5. Power-laws and Non-Power-laws in Dark Matter Halos

    E-Print Network [OSTI]

    R. N. Henriksen

    2006-09-05T23:59:59.000Z

    Simulated dark matter profiles are often modelled as a `NFW' density profile rather than a single power law. Recently, attention has turned to the rather rigorous power-law behaviour exhibited by the `pseudo phase-space density' of the dark matter halo, which is defined dimensionally in terms of the local density and velocity dispersion of the dark matter particles. The non-power-law behaviour of the density profile is generally taken to exclude simple scale-free, in-fall models; however the power-law behaviour of the `pseudo-density' is a counter indication. We argue in this paper that both behaviours may be at least qualitatively understood in terms of a dynamically evolving self-similarity, rather than the form for self-similar infall that is fixed by cosmological initial conditions. The evolution is likely due to collective relaxation such as that provided by the radial-orbit instability on large scales. We deduce, from a distribution function given by first order coarse-graining, both the NFW-type density profile and the power-law pseudo-density profile. The results are not greatly sensitive to variation about 3 in the power of the velocity dispersion used in the definition of the phase space pseudo-density. We suggest that the power 2 may create the more physical quantity, whose deviations from a power-law are a diagnostic of incomplete relaxation.

  6. Brightest Cluster Galaxies in the Extended GMRT radio halo cluster sample. Radio properties and cluster dynamics

    E-Print Network [OSTI]

    Kale, Ruta; Cassano, Rossella; Giacintucci, Simona; Bardelli, sandro; Dallacasa, Daniele; Zucca, Elena

    2015-01-01T23:59:59.000Z

    Brightest Cluster Galaxies (BCGs) show exceptional properties over the whole electromagnetic spectrum. Their special location at the centres of galaxy clusters raises the question of the role of the environment on their radio properties. To decouple the effect of the galaxy mass and of the environment in their statistical radio properties, we investigate the possible dependence of the occurrence of radio loudness and of the fractional radio luminosity function on the dynamical state of the hosting cluster. We studied the radio properties of the BCGs in the Extended GMRT Radio Halo Survey (EGRHS). We obtained a statistical sample of 59 BCGs, which was divided into two classes, depending on the dynamical state of the host cluster, i.e. merging (M) and relaxed (R). Among the 59 BCGs, 28 are radio-loud, and 31 are radio--quiet. The radio-loud sources are located favourably located in relaxed clusters (71\\%), while the reverse is true for the radio-quiet BCGs, mostly located in merging systems (81\\%). The fraction...

  7. On the occurrence of Radio Halos in galaxy clusters - Insight from a mass-selected sample

    E-Print Network [OSTI]

    Cuciti, V; Brunetti, G; Dallacasa, D; Kale, R; Ettori, S; Venturi, T

    2015-01-01T23:59:59.000Z

    Giant radio halos (RH) are diffuse Mpc-scale synchrotron sources detected in a fraction of massive and merging galaxy clusters. An unbiased study of the statistical properties of RHs is crucial to constrain their origin and evolution. We aim at investigating the occurrence of RHs and its dependence on the cluster mass in a SZ-selected sample of galaxy clusters, which is as close as possible to be a mass-selected sample. Moreover, we analyse the connection between RHs and merging clusters. We select from the Planck SZ catalogue (Planck Collaboration XXIX 2014) clusters with $M\\geq 6\\times10^{14} M_\\odot$ at z=0.08-0.33 and we search for the presence of RHs using the NVSS for z<0.2 and the GMRT RH survey (GRHS, Venturi et al. 2007, 2008) and its extension (EGRHS, Kale et al. 2013, 2015) for 0.2

  8. Qualitative and analytical results of the bifurcation thresholds to halo orbits

    E-Print Network [OSTI]

    Sara Bucciarelli; Marta Ceccaroni; Alessandra Celletti; Giuseppe Pucacco

    2015-02-01T23:59:59.000Z

    We study the dynamics in the neighborhood of the collinear Lagrangian points in the spatial, circular, restricted three--body problem. We consider the case in which one of the primaries is a radiating body and the other is oblate (although the latter is a minor effect). Beside having an intrinsic mathematical interest, this model is particularly suited for the description of a mission of a spacecraft (e.g., a solar sail) to an asteroid. The aim of our study is to investigate the occurrence of bifurcations to halo orbits, which take place as the energy level is varied. The estimate of the bifurcation thresholds is performed by analytical and numerical methods: we find a remarkable agreement between the two approaches. As a side result, we also evaluate the influence of the different parameters, most notably the solar radiation pressure coefficient, on the dynamical behavior of the model. To perform the analytical and numerical computations, we start by implementing a center manifold reduction. Next, we estimate the bifurcation values using qualitative techniques (e.g. Poincar\\'e surfaces, frequency analysis, FLIs). Concerning the analytical approach, following \\cite{CPS} we implement a resonant normal form, we transform to suitable action-angle variables and we introduce a detuning parameter measuring the displacement from the synchronous resonance. The bifurcation thresholds are then determined as series expansions in the detuning. Three concrete examples are considered and we find in all cases a very good agreement between the analytical and numerical results.

  9. Dark Matter Halos in Galaxies and Globular Cluster Populations. II: Metallicity and Morphology

    E-Print Network [OSTI]

    Harris, William; Hudson, Michael

    2015-01-01T23:59:59.000Z

    An increasing body of data reveals a one-to-one linear correlation between galaxy halo mass and the total mass in its globular cluster (GC) population, M_{GCS} ~ M_h^{1.03 \\pm 0.03}, valid over 5 orders of magnitude. We explore the nature of this correlation for galaxies of different morphological types, and for the subpopulations of metal-poor (blue) and metal-rich (red) GCs. For the subpopulations of different metallicity we find M_{GCS}(blue) ~ M_h^{0.96 \\pm 0.03} and M_{GCS}(red) ~ M_h^{1.21 \\pm 0.03} with similar scatter. The numerical values of these exponents can be derived from the detailed behavior of the red and blue GC fractions with galaxy mass and provide a self-consistent set of relations. In addition, all morphological types (E, S0, S/Irr) follow the same relation, but with a second-order trend for spiral galaxies to have a slightly higher fraction of metal-rich GCs for a given mass. These results suggest that the amount of gas available for GC formation at high redshift was in nearly direct pr...

  10. The contribution of Oxygen-Neon white dwarfs to the MACHO content of the Galactic Halo

    E-Print Network [OSTI]

    J. Camacho; S. Torres; J. Isern; L. G. Althaus; E. Garcia-Berro

    2007-06-18T23:59:59.000Z

    The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy. However, several constraints on the role played by regular carbon-oxygen white dwarfs exist. Massivewhite dwarfs are thought to be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is larger than those of typical carbon-oxygen white dwarfs and they fade to invisibility in short timescales. Consequently, they constitute a good candidate for explaining the microlensing results. Here, we examine in detail this hypothesis by using the most recent and up-to-date cooling tracks for massive white dwarfs and a Monte Carlo simulator which takes into account the most relevant Galactic inputs. We find that oxygen-neon white dwarfs cannot account for a substantial fraction of the microlensing depth towards the LMC, independently of the adopted initial mass function, although some microlensing events could be due to oxygen--neon white dwarfs. The white dwarf population contributes at most a 5% to the mass of the Galactic halo.

  11. Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo (T-980)

    SciTech Connect (OSTI)

    Shiltsev, V.; Annala, G.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N.; Reilly, R.; Still, D.; Tesarek, R.; Zagel, J.; /Fermilab; Peggs, S.; /Brookhaven /CERN /Serpukhov, IHEP /INFN, Ferrara /PNPI, CSTD

    2010-05-01T23:59:59.000Z

    The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding beam collimation simultaneously using crystals in both the vertical and horizontal plane has been made in the regime with horizontally channeled and vertically volume-reflected beams. Planning is underway for significant hardware improvements during the FY10 summer shutdown and for dedicated studies during the final year of Tevatron operation and also for a 'post-collider beam physics running' period.

  12. The Cosmological Quark-Hadron Transition and Massive Compact Halo Objects

    E-Print Network [OSTI]

    Shibaji Banerjee; Abhijit Bhattacharyya; Sanjay K. Ghosh; Sibaji Raha; Bikash Sinha

    2000-02-01T23:59:59.000Z

    One of the abiding mysteries in the so-called standard cosmological model is the nature of the dark matter. It is universally accepted that there is an abundance of matter in the universe which is non-luminous, due to their very weak interaction, if at all, with the other forms of matter, excepting of course the gravitational attraction. Speculations as to the nature of dark matter are numerous, often bordering on exotics, and searches for such exotic matter is a very active field of astroparticle physics at the dawn of the new century. Nevertheless, in recent years, there has been experimental evidence for at least one form of dark matter - the massive compact halo objects detected through gravitational microlensing effects proposed by Paczynski some years ago. To date, no clear consensus as to what these objects, referred to in the literature as well as in the following by the acronym MACHO, are made of; for a brief discussion of some of the suggestions, see below. In this work, we show that they find a natural explanation as leftover relics from the putative first order cosmic quark - hadron phase transition that is predicted by the standard model of particle interactions to have occurred during the microsecond epoch of the early universe.

  13. Assessing inflow rates in atomic cooling halos: implications for direct collapse black holes

    E-Print Network [OSTI]

    Latif, M A

    2015-01-01T23:59:59.000Z

    Supermassive black holes are not only common in the present-day galaxies, but billion solar masses black holes also powered $z\\geq 6$ quasars. One efficient way to form such black holes is the collapse of a massive primordial gas cloud into a so-called direct collapse black hole. The main requirement for this scenario is the presence of large accretion rates of $\\rm \\geq 0.1~M_{\\odot}/yr$ to form a supermassive star. The prime aim of the present work is to determine how and under what conditions such accretion rates can be obtained. We perform high resolution cosmological simulations for three primordial halos of a few times $\\rm 10^7~M_{\\odot}$ illuminated by an external UV flux, $\\rm J_{21}=100-1000$. We find that a rotationally supported structure of about parsec size is assembled, with an aspect ratio between $\\rm 0.25 - 1$ depending upon the thermodynamical properties. Rotational support, however, does not halt collapse, and mass inflow rates of $\\rm \\sim 0.1~M_{\\odot}/yr$ can be obtained in the presence...

  14. EXTENDED HOT HALOS AROUND ISOLATED GALAXIES OBSERVED IN THE ROSAT ALL-SKY SURVEY

    SciTech Connect (OSTI)

    Anderson, Michael E.; Bregman, Joel N. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Dai, Xinyu, E-mail: michevan@umich.edu, E-mail: jbregman@umich.edu, E-mail: xdai@ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)] [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2013-01-10T23:59:59.000Z

    We place general constraints on the luminosity and mass of hot X-ray-emitting gas residing in extended 'hot halos' around nearby massive galaxies. We examine stacked images of 2165 galaxies from the 2MASS Isolated Galaxy Catalog as well as subsets of this sample based on galaxy morphology and K-band luminosity. We detect X-ray emission at high confidence (ranging up to nearly 10{sigma}) for each subsample of galaxies. The average L{sub X} within 50 kpc is 1.0 {+-} 0.1 (statistical) {+-}0.2 (systematic) Multiplication-Sign 10{sup 40} erg s{sup -1}, although the early-type galaxies are more than twice as luminous as the late-type galaxies. Using a spatial analysis, we also find evidence for extended emission around five out of seven subsamples (the full sample, the luminous galaxies, early-type galaxies, luminous late-type galaxies, and luminous early-type galaxies) at 92.7%, 99.3%, 89.3%, 98.7%, and 92.1% confidence, respectively. Several additional lines of evidence also support this conclusion and suggest that about 1/2 of the total emission is extended, and about 1/3 of the extended emission comes from hot gas. For the sample of luminous galaxies, which has the strongest evidence for extended emission, the average hot gas mass is 4 Multiplication-Sign 10{sup 9} M {sub Sun} within 50 kpc and the implied accretion rate is 0.4 M {sub Sun} yr{sup -1}.

  15. Evolution of the luminosity-to-halo mass relation of LRGs from a combined SDSS-DR10+RCS2 analysis

    E-Print Network [OSTI]

    van Uitert, Edo; Hoekstra, Henk; Herbonnet, Ricardo

    2015-01-01T23:59:59.000Z

    We study the evolution of the luminosity-to-halo mass relation of Luminous Red Galaxies (LRGs). We select a sample of 52 000 LOWZ and CMASS LRGs from the Baryon Oscillation Spectroscopic Survey (BOSS) SDSS-DR10 in the ~450 deg^2 that overlaps with imaging data from the second Red-sequence Cluster Survey (RCS2), group them into bins of absolute magnitude and redshift and measure their weak lensing signals. The source redshift distribution has a median of 0.7, which allows us to study the lensing signal as a function of lens redshift. We interpret the lensing signal using a halo model, from which we obtain the halo masses as well as the normalisations of the mass-concentration relations. We find that the concentration of haloes that host LRGs is consistent with dark matter only simulations once we allow for miscentering or satellites in the modelling. The slope of the luminosity-to-halo mass relation has a typical value of 1.4 and does not change with redshift, but we do find evidence for a change in amplitude:...

  16. OXYGEN ABUNDANCES IN NEARBY FGK STARS AND THE GALACTIC CHEMICAL EVOLUTION OF THE LOCAL DISK AND HALO

    SciTech Connect (OSTI)

    Ramirez, I.; Lambert, D. L. [McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States)] [McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Allende Prieto, C. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain)] [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2013-02-10T23:59:59.000Z

    Atmospheric parameters and oxygen abundances of 825 nearby FGK stars are derived using high-quality spectra and a non-local thermodynamic equilibrium analysis of the 777 nm O I triplet lines. We assign a kinematic probability for the stars to be thin-disk (P {sub 1}), thick-disk (P {sub 2}), and halo (P {sub 3}) members. We confirm previous findings of enhanced [O/Fe] in thick-disk (P {sub 2} > 0.5) relative to thin-disk (P {sub 1} > 0.5) stars with [Fe/H] {approx}< -0.2, as well as a 'knee' that connects the mean [O/Fe]-[Fe/H] trend of thick-disk stars with that of thin-disk members at [Fe/H] {approx}> -0.2. Nevertheless, we find that the kinematic membership criterion fails at separating perfectly the stars in the [O/Fe]-[Fe/H] plane, even when a very restrictive kinematic separation is employed. Stars with 'intermediate' kinematics (P {sub 1} < 0.7, P {sub 2} < 0.7) do not all populate the region of the [O/Fe]-[Fe/H] plane intermediate between the mean thin-disk and thick-disk trends, but their distribution is not necessarily bimodal. Halo stars (P {sub 3} > 0.5) show a large star-to-star scatter in [O/Fe]-[Fe/H], but most of it is due to stars with Galactocentric rotational velocity V < -200 km s{sup -1}; halo stars with V > -200 km s{sup -1} follow an [O/Fe]-[Fe/H] relation with almost no star-to-star scatter. Early mergers with satellite galaxies explain most of our observations, but the significant fraction of disk stars with 'ambiguous' kinematics and abundances suggests that scattering by molecular clouds and radial migration have both played an important role in determining the kinematic and chemical properties of solar neighborhood stars.

  17. Baryon Cycling in the Low-Redshift Circumgalactic Medium: A Comparison of Simulations to the COS-Halos Survey

    E-Print Network [OSTI]

    Ford, Amanda Brady; Dave, Romeel; Tumlinson, Jason; Bordoloi, Rongmon; Katz, Neal; Kollmeier, Juna A; Oppenheimer, Benjamin D; Peeples, Molly S; Prochaska, Jason X; Weinberg, David H

    2015-01-01T23:59:59.000Z

    We analyze the low-redshift (z~0.2) circumgalactic medium by comparing absorption-line data from the COS-Halos Survey to absorption around a matched galaxy sample from two cosmological hydrodynamic simulations. The models include different prescriptions for galactic outflows, namely hybrid energy/momentum driven wind (ezw), and constant winds (cw). We extract for comparison direct observables including equivalent widths, covering factors, ion ratios, and kinematics. Both wind models are generally in good agreement with these observations for HI and certain low ionization metal lines, but show poorer agreement with higher ionization metal lines including SiIII and OVI that are well-observed by COS-Halos. These discrepancies suggest that both wind models predict too much cool, metal-enriched gas and not enough hot gas, and/or that the metals are not sufficiently well-mixed. This may reflect our model assumption of ejecting outflows as cool and unmixing gas. Our ezw simulation includes a heuristic prescription t...

  18. The build-up of the cD halo of M87 - evidence for accretion in the last Gyr

    E-Print Network [OSTI]

    Longobardi, A; Gerhard, O; Mihos, J C

    2015-01-01T23:59:59.000Z

    We present kinematic and photometric evidence for an accretion event in the halo of the cD galaxy M87 in the last Gyr. Using velocities for ~300 planetary nebulas (PNs) in the M87 halo, we identify a chevron-like substructure in the PN phase-space. We implement a probabilistic Gaussian mixture model to identify the PNs that belong to the chevron. From analysis of deep V-band images of M87, we find that the region with the highest density of PNs associated to the chevron, is a crown-shaped substructure in the optical light. We assign a total of N_(PN,sub)=54 to the substructure, which extends over ~50 kpc along the major axis where we also observe radial variations of the ellipticity profile and a colour gradient. The substructure has highest surface brightness in a 20kpc x 60kpc region around 70 kpc in radius. In this region, it causes an increase in surface brightness by >60%. The accretion event is consistent with a progenitor galaxy with a V-band luminosity of L=2.8\\pm1.0 x 10^9 L_(sun,V), a colour of (B-V...

  19. The APM Survey for Cool Carbon Stars in the Galactic Halo - II The Search for Dwarf Carbon Stars

    E-Print Network [OSTI]

    E. J. Totten; M. J. Irwin; P. A. Whitelock

    2000-01-07T23:59:59.000Z

    We present proper motion measurements for carbon stars found during the APM Survey for Cool Carbon Stars in the Galactic Halo (Totten & Irwin, 1998). Measurements are obtained using a combination of POSSI, POSSII and UKST survey plates supplemented where necessary by CCD frames taken at the Isaac Newton Telescope. We find no significant proper motion for any of the new APM colour-selected carbon stars and so conclude that there are no dwarf carbon stars present within this sample. We also present proper motion measurements for three previously known dwarf carbon stars and demonstrate that these measurements agree favourably with those previously quoted in the literature, verifying our method of determining proper motions. Results from a complimentary program of JHK photometry obtained at the South African Astronomical Observatory are also presented. Dwarf carbon stars are believed to have anomalous near-infrared colours, and this feature is used for further investigation of the nature of the APM carbon stars. Our results support the use of JHK photomtery as a dwarf/giant discriminator and also reinforce the conclusion that none of the new APM-selected carbon stars are dwarfs. Finally, proper motion measurements combined with extant JHK photometry are presented for a sample of previously known Halo carbon stars, suggesting that one of these stars, CLS29, is likely to be a previously unrecognised dwarf carbon star.

  20. HaloTag protein-mediated specific labeling of living cells with quantum dots Min-kyung So, Hequan Yao 1

    E-Print Network [OSTI]

    Rao, Jianghong

    ], peptides [19­20], or nucleic acids [21], fol- lowed by further functionalization with biorecognition step with quantum dot conjugates that are functionalized with HaloTag ligand, or in two steps on the size of the nanoparticles--larger size produces longer emission wave- length [10]. All these potential

  1. Models of thin discs and spheroidal haloes with masses in a linear relationship: mass estimates for NGC4389 and UGC6969

    E-Print Network [OSTI]

    Guillermo A. González; J. Ibáñez; Jerson I. Reina

    2011-11-16T23:59:59.000Z

    A family of models of thin discs and spheroidal haloes with masses in a linear relationship is presented. The models are obtained by considering the gravitational potential as the superposition of two independent components, a potential generated by the thin galactic disc and a potential generated by the spheroidal halo. The models leads to an expression for the circular velocity that can be adjusted very accurately to the observed rotation curves of some specific galaxies, in such a way that the models are stable against radial and vertical perturbations. Two particular models for galaxies NGC4389 and UGC6969 are obtained by adjusting the circular velocity with data taken from the recent paper by Verheijen & Sancici (2001). The values of the halo mass, the disc mass and the total mass for these two galaxies are computed in such a way that we obtain a very narrow interval of values for these quantities. Furthermore, the values of masses here obtained are in perfect agreement with the expected order of magnitude and with the relative order of magnitude between the halo mass and the disc mass.

  2. The Agilent HaloPlex Target Enrichment System enables fast, simple, and efficient analysis of genomic regions of interest for a large number of samples, covering

    E-Print Network [OSTI]

    Summary The Agilent HaloPlex Target Enrichment System enables fast, simple, and efficient analysis · Expanded capture size ­ enrich thousands of targets, all in a single tube · Intuitive Design Wizard ENRICHMENT SYSTEM What a Difference a Day Makes Complete Target Enrichment in Less Than a Day Design Size

  3. Ceramic Mugs & Dishes Incandescent Light Bulbs

    E-Print Network [OSTI]

    Yamamoto, Keith

    , MU East Rock Hall/19-B CELL PHONES - EYEGLASSES 654 Minnesota Street Room 208, copy room CVRI Helen. Zion Cancer Research Building N423 Parnassus Campus: eyeglasses "I" level, Optometry Store, MU West

  4. Unique decay process: {beta}-delayed emission of a proton and a neutron by the {sup 11}Li halo nucleus

    SciTech Connect (OSTI)

    Baye, D.; Descouvemont, P.; Tursunov, E. M. [Physique Quantique, CP 165/82, and Physique Nucleaire Theorique et Physique Mathematique, CP 229, Universite Libre de Bruxelles (ULB), B-1050 Brussels (Belgium); Institute of Nuclear Physics, Uzbekistan Academy of Sciences, 100214, Ulugbek, Tashkent (Uzbekistan)

    2010-11-15T23:59:59.000Z

    The neutron-rich {sup 11}Li halo nucleus is unique among nuclei with known separation energies in its ability to emit a proton and a neutron in a {beta}-decay process. The branching ratio toward this rare decay mode is evaluated within a three-body model for the initial bound state and with Coulomb three-body final scattering states. The branching ratio should be comprised between two extreme cases, i.e., a lower bound 6x10{sup -12} obtained with a pure Coulomb wave and an upper bound 5x10{sup -10} obtained with a plane wave. A simple model with modified Coulomb waves provides plausible values between 0.8x10{sup -10} and 2.2x10{sup -10}, with most probable total energies of the proton and neutron between 0.15 and 0.3 MeV.

  5. A unique decay process: beta delayed emission of a proton and a neutron by the $^{11}$Li halo nucleus

    E-Print Network [OSTI]

    Baye, D; Tursunov, E M

    2010-01-01T23:59:59.000Z

    The neutron-rich $^{11}$Li halo nucleus is unique among nuclei with known separation energies by its ability to emit a proton and a neutron in a $\\beta$ decay process. The branching ratio towards this rare decay mode is evaluated within a three-body model for the initial bound state and with Coulomb three-body final scattering states. The branching ratio should be comprised between two extreme cases, i.e.\\ a lower bound $6 \\times 10^{-12}$ obtained with a pure Coulomb wave and an upper bound $5 \\times 10^{-10}$ obtained with a plane wave. A simple model with modified Coulomb waves provides plausible values between between $0.8 \\times 10^{-10}$ and $2.2 \\times 10^{-10}$ with most probable total energies of the proton and neutron between 0.15 and 0.3 MeV.

  6. A unique decay process: beta delayed emission of a proton and a neutron by the $^{11}$Li halo nucleus

    E-Print Network [OSTI]

    D. Baye; P. Descouvemont; E. M. Tursunov

    2010-12-28T23:59:59.000Z

    The neutron-rich $^{11}$Li halo nucleus is unique among nuclei with known separation energies by its ability to emit a proton and a neutron in a $\\beta$ decay process. The branching ratio towards this rare decay mode is evaluated within a three-body model for the initial bound state and with Coulomb three-body final scattering states. The branching ratio should be comprised between two extreme cases, i.e.\\ a lower bound $6 \\times 10^{-12}$ obtained with a pure Coulomb wave and an upper bound $5 \\times 10^{-10}$ obtained with a plane wave. A simple model with modified Coulomb waves provides plausible values between between $0.8 \\times 10^{-10}$ and $2.2 \\times 10^{-10}$ with most probable total energies of the proton and neutron between 0.15 and 0.3 MeV.

  7. PROBING THE TRUNCATION OF GALAXY DARK MATTER HALOS IN HIGH-DENSITY ENVIRONMENTS FROM HYDRODYNAMICAL N-BODY SIMULATIONS

    SciTech Connect (OSTI)

    Limousin, Marceau; Sommer-Larsen, Jesper; Milvang-Jensen, Bo [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Natarajan, Priyamvada [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)], E-mail: marceau.limousin@oamp.fr

    2009-05-10T23:59:59.000Z

    We analyze high-resolution, N-body hydrodynamical simulations of fiducial galaxy clusters to probe tidal stripping of the dark matter subhalos. These simulations include a prescription for star formation allowing us to track the fate of the stellar component as well. We investigate the effect of tidal stripping on cluster galaxies hosted in these dark matter subhalos as a function of projected cluster-centric radius. To quantify the extent of the dark matter halos of cluster galaxies, we introduce the half-mass radius r {sub 1/2} as a diagnostic, and study its evolution with projected cluster-centric distance R as a function of redshift. We find a well-defined trend for (r {sub 1/2}, R): the closer the galaxies are to the center of the cluster, the smaller the half-mass radius. Interestingly, this trend is inferred in all redshift frames examined in this work ranging from z = 0 to z = 0.7. At z = 0, galaxy halos in the central regions of clusters are found to be highly truncated, with the most compact half-mass radius of 10 kpc. We also find that r {sub 1/2} depends on luminosity and we present scaling relations of r {sub 1/2} with galaxy luminosity. The corresponding total mass of the cluster galaxies is also found to increase with projected cluster-centric distance and luminosity, but with more scatter than the (r {sub 1/2}, R) trend. Comparing the distribution of stellar mass to total mass for cluster galaxies, we find that the dark matter component is preferentially stripped, whereas the stellar component is much less affected by tidal forces. We compare these results with galaxy-galaxy lensing probes of r {sub 1/2} and find qualitative agreement. Future surveys with space-based telescopes such as DUNE and SNAP, that combine wide-field and high-resolution imaging, will be able to probe the predicted (r {sub 1/2}, R) relation observationally.

  8. Neutron Halo Isomers in Stable Nuclei and their Possible Application for the Production of Low Energy, Pulsed, Polarized Neutron Beams of High Intensity and High Brilliance

    E-Print Network [OSTI]

    D. Habs; M. Gross; P. G. Thirolf; P. Böni

    2010-09-30T23:59:59.000Z

    We propose to search for neutron halo isomers populated via $\\gamma$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $\\gamma$-beams of high intensity and small band width ($\\le$ 0.1%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei \\cite{hansen95,tanihata96,aumann00}, the low neutron separation energy and short-range nuclear force allows the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half lives of the isomers for the $\\gamma$-decay back to the ground state in the 100 ps-$\\mu$s range. Similar to the treatment of photodisintegration of the deuteron, the neutron release from the neutron halo isomer via a second, low-energy, intense photon beam has a known much larger cross section with a typical energy threshold behavior. In the second step, the neutrons can be released as a low-energy, pulsed, polarized neutron beam of high intensity and high brilliance, possibly being much superior to presently existing beams from reactors or spallation neutron sources.

  9. Canaries in a Coal Mine: Using Globular Clusters to Place Limits on Massive Black Holes in the Galactic Halo

    E-Print Network [OSTI]

    Phil Arras; Ira Wasserman

    1998-11-23T23:59:59.000Z

    We explore the possibility that massive black holes comprise a significant fraction of the dark matter of our galaxy by studying the dissolution of galactic globular clusters bombarded by them. In our simulations, we evolve the clusters along a sequence of King models determined by changes of state resulting from collisions with the black holes. The results divide naturally into regimes of `small' and `large' black hole mass. `Small' black holes do not destroy clusters in single collisions; their effect is primarily cumulative, leading to a relation between $\\mbh$ and $\\fhalo$, the fraction of the halo in black holes of mass $\\mbh$, which is $\\fhalo\\mbh < $ constant (up to logarithmic corrections). For $\\fhalo=1$, we find $\\mbh \\simless 10^{3} \\msun$ by requiring survival of the same clusters studied by Moore (1993), who neglected cluster evolution, mass loss, and stochasticity of energy inputs in his estimates, but reached a similar conclusion. `Large' black holes may not penetrate a cluster without disrupting it; their effect is mainly catastrophic (close collisions), but also partly cumulative (distant collisions). In the large $\\mbh$ limit, $\\fhalo$ (but not $\\mbh$) can be constrained by computing the probability that a cluster survives a combination of close, destructive encounters and distant, nondestructive encounters. We find that it is unlikely that $\\fhalo \\simgreat 0.3$ by requiring 50 per cent survival probability for Moore's clusters over $10^{10}$ years.

  10. Nuclear Charge Radii of Be-7,9,10 and the one-neutron halo nucleus Be-11

    E-Print Network [OSTI]

    W. Nörtershäuser; D. Tiedemann; M. Žáková; Z. Andjelkovic; K. Blaum; M. L. Bissell; R. Cazan; G. W. F. Drake; Ch. Geppert; M. Kowalska; J. Krämer; A. Krieger; R. Neugart; R. Sánchez; F. Schmidt-Kaler; Z. -C. Yan; D. T. Yordanov; C. Zimmermann

    2009-02-05T23:59:59.000Z

    Nuclear charge radii of $^{7,9,10,11}$Be have been determined by high-precision laser spectroscopy. On-line measurements were performed with collinear laser spectroscopy in the $2s_{1/2} \\to 2p_{1/2}$ transition on a beam of Be$^{+}$ ions. Collinear and anticollinear laser beams were used simultaneously and the absolute frequency determination using a frequency comb yielded an accuracy in the isotope-shift measurements of about 1 MHz. Combination with accurate calculations of the mass-dependent isotope shifts yield nuclear charge radii. The charge radius decreases from $^7$Be to $^{10}$Be and then increases for the halo nucleus $^{11}$Be. When comparing our results with predictions of {\\it ab initio} nuclear structure calculations we find good agreement. Additionally, the nuclear magnetic moment of $^7$Be was determined to be $-1.3995(5)\\mu_{\\rm N}$ and that of $^{11}$Be from a previous $\\beta$-NMR measurement was confirmed.

  11. Radio Emitting Dust in the Free-Electron Layer of Spiral Galaxies: Testing the Disk/Halo Interface

    E-Print Network [OSTI]

    A. Ferrara; R. J. Dettmar

    1994-01-10T23:59:59.000Z

    We present a study of the radio emission from rotating, charged dust grains immersed in the ionized gas constituting the thick, H$\\alpha$-emitting disk of many spiral galaxies. Using up-to-date optical constants, the charge on the grains exposed to the diffuse galactic UV flux has been calculated. An analytical approximation for the grain charge has been derived, which is then used to obtain the grain rotation frequency. Grains are found to have substantial radio emission peaked at a cutoff frequency in the range 10-100~GHz, depending on the grain size distribution and on the efficiency of the radiative damping of the grain rotation. The dust radio emission is compared to the free-free emission from the ionized gas component; some constraints on the magnetic field strength in the observed dusty filaments are also discussed. The model can be used to test the disk-halo interface environment in spiral galaxies, to determine the amount and size distribution of dust in their ionized component, and to investigate the rotation mechanisms for the dust. Numerical estimates are given for experimental purposes.

  12. Thorium-rich halo star HD221170: further evidence against the universality of the r-process

    E-Print Network [OSTI]

    Alexander Yushchenko; Vera Gopka; Stephane Goriely; Faig Musaev; Angelina Shavrina; Chulhee Kim; Young Woon Kang; Juliana Kuznietsova; Vladimir Yushchenko

    2004-09-22T23:59:59.000Z

    We report the abundance determination in the atmosphere of the bright halo star HD221170. The spectra were taken with the Terskol Observatory's 2.0-m telescope with a resolution R=45000 and signal-to-noise ratio up to 250 in the wavelength region 3638-10275 \\AA. The adopted atmospheric parameters correspond to an effective temperature \\Tef=4475 K, a surface gravity \\lgg=1.0, a microturbulent velocity \\vmi=1.7 \\kms, and a macroturbulent velocity \\vma=4 \\kms. The abundances of 43 chemical elements were determined with the method of spectrum synthesis. The large overabundances (by 1 dex relative to iron) of elements with Z$>38$ are shown to follow the same pattern as the solar r-abundances. The present HD221170 analysis confirms the non-universality of the r-process, or more exactly the observation that the astrophysical sites hosting the r-process do not always lead to a unique relative abundance distribution for the bulk Ba to Hg elements, the Pb-peak elements, and the actinides.

  13. The Origin and Properties of X-ray-emitting Gas in the Halos of both Starburst and Normal Spiral Galaxies

    E-Print Network [OSTI]

    David K. Strickland

    2004-10-12T23:59:59.000Z

    I discuss the empirical properties of diffuse X-ray emitting gas in the halos of both nearby starburst galaxies and normal spiral galaxies, based on high resolution X-ray spectral imaging with the Chandra X-ray Observatory. Diffuse thermal X-ray emission can provide us with unique observational probes of outflow and accretion processes occurring in star-forming galaxies, and their interaction with the inter-galactic medium. I consider both the spatial distribution of the diffuse X-ray emission in and around edge-on starburst galaxies with superwinds (e.g. surface brightness profiles, distribution with respect to H-alpha and radio emission), and its spectral properties (e.g. thermal or non-thermal nature, abundance ratios, temperatures and soft and hard X-ray luminosities). These results are discussed in the context of current theoretical models of supernova-driven superwinds, and compared to the more limited data on extra-planar hot gas around edge-on normal galaxies.

  14. Chemical abundances in the extremely carbon-rich and xenon-rich halo planetary nebula H4-1

    SciTech Connect (OSTI)

    Otsuka, Masaaki [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Tajitsu, Akito, E-mail: otsuka@asiaa.sinica.edu.tw, E-mail: tajitsu@subaru.naoj.org [Subaru Telescope, NAOJ, 650 North A'ohoku Place, Hilo, HI 96720 (United States)

    2013-12-01T23:59:59.000Z

    We performed detailed chemical abundance analysis of the extremely metal-poor ([Ar/H] ? –2) halo planetary nebula (PN) H4-1 based on the multi-wavelength spectra from Subaru/HDS, GALEX, SDSS, and Spitzer/IRS and determined the abundances of 10 elements. The C and O abundances were derived from collisionally excited lines (CELs) and are almost consistent with abundances from recombination lines (RLs). We demonstrated that the large discrepancy in the C abundance between CEL and RL in H4-1 can be solved using the temperature fluctuation model. We reported the first detection of the [Xe III] ?5846 line in H4-1 and determination of its elemental abundance ([Xe/H] > +0.48). H4-1 is the most Xe-rich PN among the Xe-detected PNe. The observed abundances are close to the theoretical prediction by a 2.0 M {sub ?} single star model with an initially element rich ([r/Fe] = +2.0 dex) rapid neutron-capture process (r-process). The observed Xe abundance would be a product of the r-process in primordial supernovae. The [C/O]-[Ba/(Eu or Xe)] diagram suggests that the progenitor of H4-1 shares the evolution with carbon-enhanced metal-poor (CEMP)-r/s and CEMP-no stars. The progenitor of H4-1 is presumably a binary formed in an r-process-rich environment.

  15. WHAT YOU NEED TO MOVE-IN NECESSITIES TO BRING AT CHECK-IN

    E-Print Network [OSTI]

    Adali, Tulay

    without headphones Refrigerators more than 4.3 cubic ft. (not permitted in apartments) Water heaters-shutoff feature Immersion heaters Candles/incense/oil lamps Heat lamps/sun lamps Halogen lamps or bulbs Electric blankets Electric heaters Kerosene heaters Picture hangers/nails/double backed stick ups Air

  16. Photodissociation Dynamics of Halogen Oxide Species

    E-Print Network [OSTI]

    Dooley, Kristin S.

    2010-07-14T23:59:59.000Z

    and angular information simultaneously. Photofragment species are state-selectively ionized for detection using 2+1 REMPI (Resonance Enhanced Multi-Photon Ionization). The instrumentation employs a molecular beam of the XO radicals formed using pyrolitic...

  17. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Halo Occupation Number, Mass-to-Light Ratios and Omega(M)

    SciTech Connect (OSTI)

    Muzzin, Adam; Yee, H.K.C.; /Toronto U., Astron. Dept.; Hall, Patrick B.; /York U., Canada; Lin, Huan; /Fermilab

    2007-03-01T23:59:59.000Z

    Using K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters we examine the near-infrared properties of moderate-redshift (0.19 < z < 0.55) galaxy clusters. We find that the number of K-band selected cluster galaxies within R{sub 500} (the Halo Occupation Number, HON) is well-correlated with the cluster dynamical mass (M{sub 500}) and X-ray Temperature (T{sub x}); however, the intrinsic scatter in these scaling relations is 37% and 46% respectively. Comparison with clusters in the local universe shows that the HON-M{sub 500} relation does not evolve significantly between z = 0 and z {approx} 0.3. This suggests that if dark matter halos are disrupted or undergo significant tidal-stripping in high-density regions as seen in numerical simulations, the stellar mass within the halos is tightly bound, and not removed during the process. The total K-band cluster light (L{sub 200},K) and K-band selected richness (parameterized by B{sub gc,K}) are also correlated with both the cluster T{sub x} and M{sub 200}. The total (intrinsic) scatter in the L{sub 200,K}-M{sub 200} and B{sub gc,K}-M{sub 200} relations are 43%(31%) and 35%(18%) respectively and indicates that for massive clusters both L{sub 200,K} and B{sub gc,K} can predict M{sub 200} with similar accuracy as T{sub x}, L{sub x} or optical richness (B{sub gc}). Examination of the mass-to-light ratios of the clusters shows that similar to local clusters, the K-band mass-to-light ratio is an increasing function of halo mass. Using the K-band mass-to-light ratios of the clusters, we apply the Oort technique and find {Omega}{sub m,0} = 0.22 {+-} 0.02, which agrees well with recent combined concordance cosmology parameters, but, similar to previous cluster studies, is on the low-density end of preferred values.

  18. Overview of Recent Earth Observation What has kept the division busy for the last 25-30 years!

    E-Print Network [OSTI]

    System architect and PI/Co-I roles Development of key technologies Sensor build Calibration Employed seven pressure-modulated cells and six detectors Aim was to determine temperature and vertical-Watt and Edinburgh to supply the 183GHz H2O channel #12;HALogen Occultation Experiment (HALOE) HALOE used solar

  19. DETERMINATION OF THE POINT-SPREAD FUNCTION FOR THE FERMI LARGE AREA TELESCOPE FROM ON-ORBIT DATA AND LIMITS ON PAIR HALOS OF ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany)] [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)] [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Asano, K. [Interactive Research Center of Science, Tokyo Institute of Technology, Meguro City, Tokyo 152-8551 (Japan)] [Interactive Research Center of Science, Tokyo Institute of Technology, Meguro City, Tokyo 152-8551 (Japan); Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States)] [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Baldini, L.; Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France)] [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [CNRS, IRAP, F-31028 Toulouse cedex 4 (France)] [CNRS, IRAP, F-31028 Toulouse cedex 4 (France); Brigida, M. [Dipartimento di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy)] [Dipartimento di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P., E-mail: mdwood@slac.stanford.edu, E-mail: mar0@uw.edu [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); and others

    2013-03-01T23:59:59.000Z

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from Almost-Equal-To 20 MeV to >300 GeV. The pre-launch response functions of the LAT were determined through extensive Monte Carlo simulations and beam tests. The point-spread function (PSF) characterizing the angular distribution of reconstructed photons as a function of energy and geometry in the detector is determined here from two years of on-orbit data by examining the distributions of {gamma} rays from pulsars and active galactic nuclei (AGNs). Above 3 GeV, the PSF is found to be broader than the pre-launch PSF. We checked for dependence of the PSF on the class of {gamma}-ray source and observation epoch and found none. We also investigated several possible spatial models for pair-halo emission around BL Lac AGNs. We found no evidence for a component with spatial extension larger than the PSF and set upper limits on the amplitude of halo emission in stacked images of low- and high-redshift BL Lac AGNs and the TeV blazars 1ES0229+200 and 1ES0347-121.

  20. Hydro-Gravitational-Dynamics Interpretation of the Tadpole VV29 Merging Galaxy System: Dark-Matter-Halo-Planet Star-Cluster Wakes

    E-Print Network [OSTI]

    Carl H. Gibson

    2008-03-29T23:59:59.000Z

    Hubble Space telescope (HST) images of merging galaxy system VV29 reveal the 0.3 Mpc baryonic-dark-matter (BDM) halo composed of primordial protoglobularstarcluster (PGC) clumps of planets. Star-cluster-wakes trace the merger by formation of stars from the planets. Aligned young globular star clusters (YGCs), star-wakes and dust-trails show the frictional, spiral passage of galaxy fragments VV29cdef in a long tail-like galaxy (VV29b) as the fragments merge on the accretion disk plane of the central spiral galaxy VV29a. The observations confirm the hydro-gravitational-dynamics (HGD) prediction of Gibson 1996 and quasar microlensing inference of Schild 1996 that the dark matter of galaxies is dominated by planets (PFPs) in million-solar-mass clumps. Globular star clusters (YGCs, OGCs, PGCs) preserve the density of the plasma epoch 30,000 years after the big bang when viscous supercluster-fragmentation began. Tadpole images show linear galaxy clusters reflecting turbulent vortex lines of protogalaxy fragmentation at the 0.003 Mpc Kolmogorov-Nomura scale of the plasma before transition to gas. The halo size indicates strong diffusion of PGC primordial-planet-clumps from a cooling protogalaxy as its planets freeze.

  1. THE SPATIAL CLUSTERING OF ROSAT ALL-SKY SURVEY AGNs. II. HALO OCCUPATION DISTRIBUTION MODELING OF THE CROSS-CORRELATION FUNCTION

    SciTech Connect (OSTI)

    Miyaji, Takamitsu; Aceves, Hector [Instituto de AstronomIa, Universidad Nacional Autonoma de Mexico, Ensenada, Baja California (Mexico); Krumpe, Mirko; Coil, Alison L., E-mail: miyaji@astrosen.unam.mx [University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States)

    2011-01-10T23:59:59.000Z

    This is the second paper of a series that reports on our investigation of the clustering properties of active galactic nuclei (AGNs) in the ROSAT All-Sky Survey (RASS) through cross-correlation functions (CCFs) with Sloan Digital Sky Survey (SDSS) galaxies. In this paper, we apply the Halo Occupation Distribution (HOD) model to the CCFs between the RASS broad-line AGNs with SDSS luminous red galaxies (LRGs) in the redshift range 0.16 < z < 0.36 that was calculated in Paper I. In our HOD modeling approach, we use the known HOD of LRGs and constrain the HOD of the AGNs by a model fit to the CCF. For the first time, we are able to go beyond quoting merely a 'typical' AGN host halo mass, M{sub h}, and model the full distribution function of AGN host dark matter halos. In addition, we are able to determine the large-scale bias and the mean M{sub h} more accurately. We explore the behavior of three simple HOD models. Our first model (Model A) is a truncated power-law HOD model in which all AGNs are satellites. With this model, we find an upper limit to the slope ({alpha}) of the AGN HOD that is far below unity. The other two models have a central component, which has a step function form, where the HOD is constant above a minimum mass, without (Model B) or with (Model C) an upper mass cutoff, in addition to the truncated power-law satellite component, similar to the HOD that is found for galaxies. In these two models we find that the upper limits on {alpha} are still below unity, with {alpha} {approx}< 0.95 and {alpha} {approx}< 0.84 for Models B and C, respectively. Our analysis suggests that the satellite AGN occupation increases slower than, or may even decrease with, M{sub h}, in contrast to the satellite HODs of luminosity-threshold samples of galaxies, which, in contrast, grow approximately as (N{sub s}) {proportional_to} M{sup {alpha}}{sub h} with {alpha} {approx} 1. These results are consistent with observations that the AGN fraction in groups and clusters decreases with richness.

  2. GLOBULAR CLUSTERS IN THE OUTER GALACTIC HALO: NEW HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS IMAGING OF SIX GLOBULAR CLUSTERS AND THE GALACTIC GLOBULAR CLUSTER AGE-METALLICITY RELATION

    SciTech Connect (OSTI)

    Dotter, Aaron; Anderson, Jay [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Sarajedini, Ata [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)

    2011-09-01T23:59:59.000Z

    Color-magnitude diagrams (CMDs) derived from Hubble Space Telescope (HST) Advanced Camera for Surveys F606W, F814W photometry of six globular clusters (GCs) are presented. The six GCs form two loose groupings in Galactocentric distance (R{sub GC}): IC 4499, NGC 6426, and Ruprecht 106 at {approx}15-20 kpc and NGC 7006, Palomar 15, and Pyxis at {approx}40 kpc. The CMDs allow the ages to be estimated from the main-sequence turnoff in every case. In addition, the age of Palomar 5 (R{sub GC} {approx} 18 kpc) is estimated using archival HST Wide Field Planetary Camera 2 V, I photometry. The age analysis reveals the following: IC 4499, Ruprecht 106, and Pyxis are 1-2 Gyr younger than inner halo GCs with similar metallicities; NGC 7006 and Palomar 5 are marginally younger than their inner halo counterparts; NGC 6426 and Palomar 15, the two most metal-poor GCs in the sample, are coeval with all the other metal-poor GCs within the uncertainties. Combined with our previous efforts, the current sample provides strong evidence that the Galactic GC age-metallicity relation consists of two distinct branches. One suggests a rapid chemical enrichment in the inner Galaxy while the other suggests prolonged GC formation in the outer halo. The latter is consistent with the outer halo GCs forming in dwarf galaxies and later being accreted by the Milky Way.

  3. Statistical Physics of Dark and Normal Matter Distribution in Galaxy Formation : Dark Matter Lumps and Black Holes in Core and Halo of Galaxy

    E-Print Network [OSTI]

    Ajay Patwardhan

    2008-05-15T23:59:59.000Z

    In unified field theory the cosmological model of the universe has supersymmetric fields. Supersymmetric particles as dark and normal matter in galaxy clusters have a phase separation. Dark matter in halos have a statistical physics equation of state. Neutralino particle gas with gravitation can have a collapse of dark matter lumps. A condensate phase due to boson creation by annhillation and exchange can occur at high densities. The collapse of the boson condensate, including neutralinos, into the Schwarzschild radius creates dark matter black holes. Microscopic dark matter black holes can evaporate with Hawking effect giving gamma ray bursts and create a spectrum of normal particles. The phase separation of normal and dark matter in galaxy clusters and inside galaxies is given by statistical physics.

  4. Zevenhoven & Kilpinen Halogens, dioxins/furans 17.6.2001 7-1 Chapter 7 Halogens,

    E-Print Network [OSTI]

    Zevenhoven, Ron

    applications as HF, used in the glass industry, as UF6 used in separating 235 U and 238 U isotopes compound CCl4. Fluorine is mainly found as HF in some fossil fuel-derived gases or when processing glass

  5. A Chandra - VLA Investigation of the X-ray Cavity System and Radio Mini-Halo in the Galaxy Cluster RBS 797

    E-Print Network [OSTI]

    Doria, Alberto; Ettori, Stefano; Brighenti, Fabrizio; Nulsen, Paul E J; McNamara, Brian R

    2012-01-01T23:59:59.000Z

    We present a study of the cavity system in the galaxy cluster RBS 797 based on Chandra and VLA data. RBS 797 (z = 0.35), is one of the most distant galaxy clusters in which two pronounced X-ray cavities have been discovered. The Chandra data confirm the presence of a cool core and indicate an higher metallicity along the cavity directions. This is likely due to the AGN outburst, which lifts cool metal-rich gas from the center along the cavities, as seen in other systems. We find indications that the cavities are hotter than the surrounding gas. Moreover, the new Chandra images show bright rims contrasting with the deep, X-ray deficient cavities. The likely cause is that the expanding 1.4 GHz radio lobes have displaced the gas, compressing it into a shell that appears as bright cool arms. Finally we show that the large-scale radio emission detected with our VLA observations may be classified as a radio mini-halo, powered by the cooling flow (CF), as it nicely follows the trend P_radio vs. P_CF predicted by the...

  6. L Prize™: The Race for Super Efficient Light Bulbs

    Broader source: Energy.gov [DOE]

    This September 23, 2008 webcast provided an overview of the Bright Tomorrow Lighting Prize (L Prize) technology competition. The L Prize calls for super-efficient SSL products to replace two of the...

  7. Why Did the LED Light Bulb Cross the Road?

    Office of Energy Efficiency and Renewable Energy (EERE)

    Could using humor as a marketing strategy make energy efficiency a bit more digestible? One Illinois grant recipient thinks it could be.

  8. A Second UV "Light Bulb" behind the SN 1006 Remnant

    E-Print Network [OSTI]

    Winkler, P F; Long, Knox S.

    1997-01-01T23:59:59.000Z

    A point X-ray source located 9 arcmin northeast of the center of SN~1006 has been spectroscopically identified as a background QSO, with a redshift of 0.335. The object is moderately bright, with magnitude V=18.3. If its ultraviolet spectrum is typical of low-z quasars, this object will be a second (after the Schweizer-Middleditch star) source to use for absorption spectroscopy of material within SN 1006. Absorption spectra provide a unique probe for unshocked ejecta within this supernova remnant, and can possibly solve the long-standing problem of "missing" iron in the remnants of Type Ia supernovae.

  9. A Second UV "Light Bulb" behind the SN 1006 Remnant

    E-Print Network [OSTI]

    P. Frank Winkler; Knox S. Long

    1997-07-22T23:59:59.000Z

    A point X-ray source located 9 arcmin northeast of the center of SN~1006 has been spectroscopically identified as a background QSO, with a redshift of 0.335. The object is moderately bright, with magnitude V=18.3. If its ultraviolet spectrum is typical of low-z quasars, this object will be a second (after the Schweizer-Middleditch star) source to use for absorption spectroscopy of material within SN 1006. Absorption spectra provide a unique probe for unshocked ejecta within this supernova remnant, and can possibly solve the long-standing problem of "missing" iron in the remnants of Type Ia supernovae.

  10. Westinghouse and Fuzhou Permitted to Restart Distribution of Light Bulb

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&Management Alert WesternProducts |

  11. How Energy-Efficient Light Bulbs Compare with Traditional Incandescents |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently20,000 RussianBy: Thomas P. D'Agostino,GlenLearningDepartmentDistributed

  12. The History of the Light Bulb | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov. Are you sure you wantJoin us for|Idaho |EnergyTanklessThe CleanThe History ofThe

  13. The History of the Light Bulb | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartmentTest for PumpingThe Facts on Gas Prices:TheTheHistory ofTheThe

  14. The impact of non-LTE effects and granulation inhomogeneities on the derived iron and oxygen abundances in metal-poor halo stars

    E-Print Network [OSTI]

    Nataliya Shchukina; Javier Trujillo Bueno; Martin Asplund

    2004-10-20T23:59:59.000Z

    This paper presents the results of a detailed theoretical investigation of the impact of non-LTE effects and of granulation inhomogeneities on the derived iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our analysis is based on both the `classical' one-dimensional (1D) stellar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We find that the non-LTE effects on the iron abundance derived from Fe {\\sc i} lines are very important, amounting to ${\\sim}0.9$ dex and to ${\\sim}0.6$ dex in the 3D and 1D cases, respectively. On the other hand, we find that non-LTE and 3D effects have to be taken into account for a reliable determination of the iron abundance from weak Fe {\\sc ii} lines, because the significant overexcitation of their upper levels in the granular regions tend to produce emission features. As a result such Fe {\\sc ii} lines are weaker than in LTE and the abundance correction amounts to ${\\sim}0.4$ dex for the 3D case. We derive also the oxygen-to-iron abundance ratio in the metal-poor star HD140283 by using the O {\\sc i} triplet at 7772--5 \\AA and the forbidden [O {\\sc i}] line at 6300 \\AA. Interestingly, when both non-LTE and 3D effects are taken into account there still remains significant discrepancies in the iron abundances derived from Fe {\\sc i} and Fe {\\sc ii} lines, as well as in the oxygen abundances inferred from the O {\\sc i} and [O {\\sc i}] lines. We conclude that the metalicity of this type of metal-poor stars could be significantly larger than previously thought, which may have far-reaching implications in stellar astrophysics.

  15. Hot Gas Halos in Galaxies

    SciTech Connect (OSTI)

    Mulchaey, John S. [Carnegie Observatories (United States); Jeltema, Tesla E. [UCO/Lick Observatories (United States)

    2010-06-08T23:59:59.000Z

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

  16. Theoretical studies of the dynamics of chemical reactions

    SciTech Connect (OSTI)

    Wagner, A.F. [Argonne National Laboratory, IL (United States)

    1993-12-01T23:59:59.000Z

    Recent research effort has focussed on several reactions pertinent to combustion. The formation of the formyl radical from atomic hydrogen and carbon monoxide, recombination of alkyl radicals and halo-alkyl radicals with halogen atoms, and the thermal dissociation of hydrogen cyanide and acetylene have been studied by modeling. In addition, the inelastic collisions of NCO with helium have been investigated.

  17. Manganese Porphyrins Catalyze Selective C-H Bond Halogenations

    SciTech Connect (OSTI)

    Liu, Wei; Groves, John T

    2010-01-01T23:59:59.000Z

    We report a manganese porphyrin mediated aliphatic C?H bond chlorination using sodium hypochlorite as the chlorine source. In the presence of catalytic amounts of phase transfer catalyst and manganese porphyrin Mn(TPP)Cl 1, reaction of sodium hypochlorite with different unactivated alkanes afforded alkyl chlorides as the major products with only trace amounts of oxygenation products. Substrates with strong C?H bonds, such as neopentane (BDE =?100 kcal/mol) can be also chlorinated with moderate yield. Chlorination of a diagnostic substrate, norcarane, afforded rearranged products indicating a long-lived carbon radical intermediate. Moreover, regioselective chlorination was achieved by using a hindered catalyst, Mn(TMP)Cl, 2. Chlorination of trans-decalin with 2 provided 95% selectivity for methylene-chlorinated products as well as a preference for the C2 position. This novel chlorination system was also applied to complex substrates. With 5?-cholestane as the substrate, we observed chlorination only at the C2 and C3 positions in a net 55% yield, corresponding to the least sterically hindered methylene positions in the A-ring. Similarly, chlorination of sclareolide afforded the equatorial C2 chloride in a 42% isolated yield. Regarding the mechanism, reaction of sodium hypochlorite with the Mn{sup III} porphyrin is expected to afford a reactive Mn{sup V}?O complex that abstracts a hydrogen atom from the substrate, resulting in a free alkyl radical and a Mn{sup IV}—OH complex. We suggest that this carbon radical then reacts with a Mn{sup IV}—OCl species, providing the alkyl chloride and regenerating the reactive Mn{sup V}?O complex. The regioselectivity and the preference for CH{sub 2} groups can be attributed to nonbonded interactions between the alkyl groups on the substrates and the aryl groups of the manganese porphyrin. The results are indicative of a bent [Mn{sup v}?O---H---C] geometry due to the C—H approach to the Mn{sup v}?O (d??p?)* frontier orbital.

  18. Halogens in volcanic systems A. Aiuppa a,b

    E-Print Network [OSTI]

    Long, Bernard

    , Università di Palermo, Via archirafi 36, 90123 Palermo, Italy b Istituto Nazionale di Geofisica e Geofisica e Vulcanologia, sezione di Roma, Via di Vigna Murata 605, 00143 Roma, Italy e Department of Earth

  19. Toward the photo-induced reductive elimination of halogens

    E-Print Network [OSTI]

    Manke, David

    2005-01-01T23:59:59.000Z

    Light-driven energy conversion schemes have been proposed as alternative energy to fossil fuels. The target fuel of these schemes is hydrogen. For photocatalytic hydrogen production to be feasible, it must be performed on ...

  20. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

    1997-03-18T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

  1. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

    1995-10-03T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

  2. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

    1997-08-05T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized. by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

  3. Origin of Halogens and Nitrogen in Enstatite Chondrites

    E-Print Network [OSTI]

    Rubin, Alan E.; Choi, Byeon-Gak

    2009-01-01T23:59:59.000Z

    A. Bischoff, J. Zipfel, Mineralogy of the Neuschwanstein (minmag.1997.061.408.09 A.E. Rubin, Mineralogy of meteoriteBuseck, E.F. Holdsworth, Mineralogy and petrology of the

  4. Origin of Halogens and Nitrogen in Enstatite Chondrites

    E-Print Network [OSTI]

    Rubin, Alan E.; Choi, Byeon-Gak

    2009-01-01T23:59:59.000Z

    Holdsworth, Mineralogy and petrology of the Yilmia enstatiteD.W. Mittlefehldt, I. Casanova, Petrology, chemistry and

  5. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, M.; Slatkin, D.N.

    1997-08-05T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na{sub 4}B{sub 12}I{sub 11}SSB{sub 12}I{sub 11}, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy. 1 fig.

  6. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, M.; Slatkin, D.N.

    1997-03-18T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na{sub 4}B{sub 12}I{sub 11}SSB{sub 12}I{sub 11}, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy. 1 fig.

  7. Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy

    DOE Patents [OSTI]

    Miura, M.; Slatkin, D.N.

    1995-10-03T23:59:59.000Z

    A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na{sub 4}B{sub 12}I{sub 11}SSB{sub 12}I{sub 11}, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy. 1 fig.

  8. Transient x-ray absorption spectroscopy of hydrated halogen atom

    E-Print Network [OSTI]

    Elles, Christopher G.; Shkrob, Ilya A.; Crowell, Robert A.; Arms, Dohn A.; Landahl, Eric C.

    2008-02-11T23:59:59.000Z

    Time-resolved x-ray absorption spectroscopy has been used to observe the transient species generated by one-photon detachment of an electron from aqueous bromide. The K-edge spectrum of the short-lived Br(0) atom exhibits a resonant 1s-4p transition...

  9. Halogen eAppraisal - Performance Appraisals | The Ames Laboratory

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm) Harmonic EngineHIV and evolutionSite

  10. Barber, Whitesides I Redut'tiLleClearage of Carhon-Halogen Bonds ReductiveCleavageof Carbon-HalogenBondsby

    E-Print Network [OSTI]

    Prentiss, Mara

    halogenatom abstractionfrom thc alkyl halideby a nragnesiumatom (eq 2). c R -X * Ms, [R-X]-. sfcr + Me(l)- R

  11. Essays on Environmental and Resource Economics

    E-Print Network [OSTI]

    Toledo, Chantal Nathalie

    2013-01-01T23:59:59.000Z

    Light Bulb Offer (UC BerkeleyBetween Light Bulbs . . . . . . . . . . . . . . . . .Reasons for the Light Bulb Choice, ILB (left) or LED (right)

  12. Analysis of the California Solar Resource--Volume 3: Appendices

    E-Print Network [OSTI]

    erdahl, P.

    2011-01-01T23:59:59.000Z

    twice yearly by Weather Data: Temperature (dry bulb) (,. ,.et bulb) Wind Speed (Ht. ~) Wind Direction Other evaporationData: Temperature (dry bulb) (wet bulb) Nind Speed (Ht, Wind

  13. Demography of the Invasive Geophyte Oxalis pes-caprae Across a Mediterranean Island

    E-Print Network [OSTI]

    Traveset, Anna

    -caprae reproductive components (i.e. bulb production, bulb bank, bulb predation, bulb mortality, bulb dormancy, bulb germination, plant establishment and survival). Key Results Oxalis pes-caprae has a transient bulb bank that remains dormant in the soil during summer. High levels of bulb predation after dispersal, followed by bulb

  14. Hanford Site annual dangerous waste report, calendar year 1995

    SciTech Connect (OSTI)

    NONE

    1995-12-31T23:59:59.000Z

    This report is a compilation of data on the disposition of hazardous wastes generated on the Hanford Reservation. This information is on EPA requirement every two years. Wastes include: tank simulant waste; alkaline batteries; lead-based paints; organic solvents; light bulbs containing lead and/or mercury; monitoring well drilling wastes; soils contaminated with trace metals, halogenated organics, or other pollutants; Ni-Cd batteries; pesticides; waste oils and greases; wastes from the cleanup of fuel/gasoline spills; filters; metals; and other.

  15. Secret Ninja Testing with HALO Software Engineering

    E-Print Network [OSTI]

    Kaiser, Gail E.

    their approach to the SDLC? - How can we ensure that "everybody wins"? - What requirements must we make sure we

  16. Clusters and halos in light nuclei

    E-Print Network [OSTI]

    Thomas Neff

    2012-10-15T23:59:59.000Z

    The fermionic molecular dynamics approach uses Gaussian wave packets as single-particle basis states. Many-body basis states are Slater determinants projected on parity, angular momentum and total linear momentum. The wave-packet basis is very flexible - FMD contains harmonic oscillator shell model and Brink-type cluster states as special cases. The parameters of the wave packets are obtained by variation. A realistic effective interaction derived from the Argonne V18 interaction by means of the unitary correlation operator method is employed. We discuss the fully microscopic calculation of the 3He(alpha,gamma)7Be capture reaction within the FMD approach. The model space contains frozen cluster configurations at large distances and polarized configurations in the interaction region. The polarized configurations are essential for a successful description of the 7Be bound state properties and for the S- and D-wave scattering states. The calculated cross section agrees well with recent measurements regarding both the absolute normalization and the energy dependence. We also discuss the structure of the cluster states, including the famous Hoyle state, in 12C. From the two-body densities we conclude that the Hoyle state has a spatially extended triangular alpha-cluster structure, whereas the third 0+ state features a chain-like obtuse triangle structure. We also calculate the N hbar Omega decomposition of our wave functions to illuminate the challenges of no-core shell model calculations for these cluster states.

  17. Coulomb interactions within Halo Effective Field Theory

    E-Print Network [OSTI]

    Renato Higa

    2007-11-30T23:59:59.000Z

    I present preliminary results of effective field theory applied to nuclear cluster systems, where Coulomb interactions play a significant role.

  18. Nuclear clusters with Halo Effective Field Theory

    E-Print Network [OSTI]

    Renato Higa

    2008-09-30T23:59:59.000Z

    After a brief discussion of effective field theory applied to nuclear clusters, I present the aspect of Coulomb interactions, with applications to low-energy alpha-alpha and nucleon-alpha scattering.

  19. Saturn's moon rhea sports a dusty halo

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook Twitter Principal Investigators PostdoctoralSasha Berger

  20. A wet- and dry-bulb temperature measuring system for micrometeorological application

    E-Print Network [OSTI]

    Machetta, Joe Henry

    1965-01-01T23:59:59.000Z

    positioned shelter under test and always in such a positi. on that the prevailing wind direction was perpendicular to a line between the Assman and the shelter, and care was taken to prevent any radiation or wind shading. Readings were obtained at all... the contract interval, All of the preceding resolution evaluations are appli- cable under any and all natural conditions of radiation and wind. ACKNOWLEDGEMENTS The research efforts reported herein have been jointly sponsored by tha Air Force Cambridge...

  1. Studying some mechanical properties of MgO with used neon bulb glass

    SciTech Connect (OSTI)

    Issa, Tarik Talib [University of Baghdad, College of science physic department , Material Science group (Iraq); Khaleel, Saba Mahdi [Ministry of Industry and Minerals,Commission for Research And Industrial Development ,Chemical and Petrochemical Research Center, Baghdad (Iraq); Abdul Kareem, Noura Ammar [Ministry of Industry and Minerals, Commission for Research And Industrial Development ,Chemical and Petrochemical Research Center, Baghdad (Iraq)

    2013-12-16T23:59:59.000Z

    Ceramic compact of MgO +WT% of UNBG were sintered at different sintering temperature (700, 900, 1100, 1300)°c, under static air for 3 hours. X-ray diffraction and some mechanical properties were conducted. The maximum sintered density, compression; fracture strength and hardness were indicated for the compilation of MgO ?20 WT % UNBG, sintered at 1300 °c.

  2. Zinc released from olfactory bulb glomeruli by patterned electrical stimulation of the olfactory nerve

    E-Print Network [OSTI]

    Blakemore, Laura J.

    Zinc is a trace element with a multitude of roles in biological systems including structural and cofactor functions for proteins. Although most zinc in the central nervous system (CNS) is protein bound, the CNS contains a ...

  3. Consumer Light Bulb Changes: Briefing and Resources for Media and Retailers

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T, Inc.'sEnergyTexas1.SpaceFluor Federal ServicesDepartment ofDepartment of|

  4. Westinghouse Pays $50,000 Civil Penalty to Resolve Light Bulb Efficiency

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&Management Alert Western

  5. What Light Bulbs Do You Use in Your Home? | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&Management AlertWhatOnOn

  6. Which Bulb Is Right for You? (High-Resolution EPS Billboard) | Department

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&ManagementEfficiency |Aof Energy

  7. Which Bulb Is Right for You? (High-Resolution JPG Billboard) | Department

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&ManagementEfficiency |Aof

  8. Which Bulb Is Right for You? (Low-Resolution JPG Billboard) | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradley Nickell DirectorThe&ManagementEfficiency |AofEnergy

  9. Buying the Perfect Energy-Efficient Light Bulb in 5 Easy Steps | Department

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the YouTube platformBuilding Removal Ongoing atGreenhouse GasesRespond to

  10. A Winning Light Bulb With the Potential to Save the Nation Billions |

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov. Are you sure you wantJoin us for|IdahotheWhatProposed - FINALAA Tale of

  11. DOE Requires Westinghouse to Cease Sales of Two Light Bulb Models and

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"WaveInteractions and PolicyCybersecurity ThreatsViolatingAllows Sale of

  12. DOE Withdraws the Energy Star Label from 34 Compact Fluorescent Light Bulbs

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"WaveInteractionsMaterials | DepartmentEnergy Will Not| Department

  13. Demonstration Assessment of Light Emitting Diode (LED) Residential Downlights and Undercabinet Lights in the Lane County Tour of Homes, Eugene, Oregon

    SciTech Connect (OSTI)

    Ton, My K.; Richman, Eric E.; Gilbride, Theresa L.

    2008-11-10T23:59:59.000Z

    In August 2008 the Pacific Northwest National Laboratory (PNNL) conducted a light emitting diode (LED) residential lighting demonstration project for the U.S. Department of Energy (DOE), Office of Building Technologies, as part of DOE’s Solid State Lighting (SSL) Technology Demonstration Gateway Program. Two lighting technologies, an LED replacement for downlight lamps (bulbs) and an LED undercabinet lighting fixture, were tested in the demonstration which was conducted in two homes built for the 2008 Tour of Homes in Eugene, Oregon. The homes were built by the Lane County Home Builders Association (HBA), and Future B Homes. The Energy Trust of Oregon (ETO) also participated in the demonstration project. The LED downlight product, the LR6, made by Cree LED Lighting Solutions acts as a screw-in replacement for incandescent and halogen bulbs in recessed can downlights. The second product tested is Phillips/Color Kinetics’ eW® Profile Powercore undercabinet fixture designed to mount under kitchen cabinets to illuminate the countertop and backsplash surfaces. Quantitative and qualitative measurements of light performance and electrical power usage were taken at each site before and after initially installed halogen and incandescent lamps were replaced with the LED products. Energy savings and simple paybacks were also calculated and builders who toured the homes were surveyed for their responses to the LED products. The LED downlight product drew 12 Watts of power, cutting energy use by 82% compared to the 65W incandescent lamp and by 84% compared to the 75W halogen lamp. The LED undercabinet fixture drew 10 watts, cutting energy use by 83% to 90% compared to the halogen product, which was tested at two power settings: a low power 60W setting and a high power 105W setting. The LED downlight consistently provided more light than the halogen and incandescent lamps in horizontal measurements at counter height and floor level. It also outperformed in vertical illuminance measurements taken on the walls, indicating better lateral dispersion of the light. The undercabinet fixture’s light output was midway between the low and high power halogen undercabinet fixture light outputs (35.8 foot candle versus 13.4 fc and 53.4 fc) but it produced a more uniform light (max/min ratio of 7.0 versus 10.8). The color correlated temperature (CCT, the blue or yellowness) of the LED light correlated well with the halogen and incandescent lights (2675 K vs 2700 K). The color rendering of the LED downlight also correlated well at 92 CRI compared to 100 CRI for the halogen and incandescent lamps. The LED undercabinet fixture had measures of 2880 K CCT and 71 CRI compared to the 2700 K and 100 CRI scores for the halogen undercabinet fixture. Builders who toured the homes were surveyed; they gave the LED downlight high marks for brightness, said the undercabinet improved shadows and glare and said both products improved overall visibility, home appearance, and home value. Paybacks on the LED downlight ranged from 7.6 years (assuming electricity cost of 11 c/kWh) to 13.5 years (at 5C/kWh). Paybacks on the LED undercabinet fixture in a new home ranged from 4.4 years (11c/kWh electricity) to 7.6 years (5c/kWh) based on product costs of $95 per LED downlight and $140 per LED undercabinet fixture at 3 hrs per day of usage for the downlight and 2 hrs per day for the undercabinet lighting.

  14. The galaxy - dark matter halo connection: which galaxy properties are correlated with the host halo mass?

    E-Print Network [OSTI]

    Contreras, S; Norberg, P; Padilla, N

    2015-01-01T23:59:59.000Z

    We demonstrate how the properties of a galaxy depend on the mass of its host dark matter subhalo, using two independent models of galaxy formation. For the cases of stellar mass and black hole mass, the median property value displays a monotonic dependence on subhalo mass. The slope of the relation changes for subhalo masses for which heating by active galactic nuclei becomes important. The median property values are predicted to be remarkably similar for central and satellite galaxies. The two models predict considerable scatter around the median property value, though the size of the scatter is model dependent. There is only modest evolution with redshift in the median galaxy property at a fixed subhalo mass. Properties such as cold gas mass and star formation rate, however, are predicted to have a complex dependence on subhalo mass. In these cases subhalo mass is not a good indicator of the value of the galaxy property. We illustrate how the predictions in the galaxy property - subhalo mass plane differ fr...

  15. Math 3339 Fall 2012 Name: Please, write clearly and justify all your steps, to get proper credit for your work. No notes, books

    E-Print Network [OSTI]

    Labate, Demetrio

    light bulbs, 3 are defective. The bulbs are selected at random and tested, one at a time, until the third defective bulb is found. Compute the probability that the third defective bulb is: (i) the third bulb tested; (ii) the fifth bulb tested; (iii) the tenth bulb tested. #12;(3)[8 Pts] A survey

  16. Halogen-elimination photochemistry and oxygen-activation chemistry of late transition-metal complexes

    E-Print Network [OSTI]

    Teets, Thomas S. (Thomas Sebastian)

    2012-01-01T23:59:59.000Z

    Multi-electron reaction chemistry, from both ground- and excited-state species, is at the heart of many topics in renewable energy and catalysis. In this thesis, two classes of reactions central to the themes of energy ...

  17. Gold and gold-graphene used as cathodic interfaces for scission of carbon-halogen bonds.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . Application to the building of anthraquinone-Au electrodes. Jacques Simonet a * and Viatcheslav Jouikov b a as cathode material. This first work points out the immobilization of anthraquinone (AQ) in organic polar.12.024 #12;2 Graphical Abstract Key Words: Graphene; 2-Bromomethylanthraquinone; Anthraquinone electrodes

  18. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    B. , Hebestreit, K. , and Platt, U. : Short-lived alkylR. , Lawrence, M. G. , Platt, U. , ,and Crutzen, P. J. :Peleg, M. , Luria, M. , and Platt, U. : DOAS measurements of

  19. Halogen diffusion in a basaltic melt Marina Alletti a,*, Don R. Baker b,c

    E-Print Network [OSTI]

    Long, Bernard

    , Montreal, Quebec, Canada c Sezione di Sismologia e Tettonofisica, Istituto Nazionale di Geofisica e

  20. Halogen-Based Plasma Etching of Novel Field-Effect Transistor Gate Materials

    E-Print Network [OSTI]

    Kiehlbaugh, Kasi Michelle

    2009-01-01T23:59:59.000Z

    Surface Interactions in Fluorocarbon Etching of Silicon2706. Xu, S.L. , et al. , Fluorocarbon polymer formation,

  1. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    close to or East of the Canary Islands, before arriving atpassing near to the Canary Islands on its way to Cape Verde.passing close to the Canary islands before approaching Cape

  2. Supplementary material for ACP manuscripts "A chemical probe technique for the determination of reactive halogen

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    and the sample was saturated with sodium sulfate and extracted twice with 5.0 mL of ethyl acetate. The extracts-linear inverse plots and the influence of allyl alcohol in bromide solutions The kinetic derivation that describes the non-linear inverse plots (e.g., Figure 2 in Part 1), and the effect that allyl alcohol has

  3. The Halogenation of Oils with Special Attention to the Method of Wijs

    E-Print Network [OSTI]

    Rhodes, Edmund Oliver

    1913-05-15T23:59:59.000Z

    the separation of iodine when various substances were treated with Wijs1 solution and offered the following suggestions as to the causes: !• The addition of chlorine by the substance, and liberation of free iodine, but this does not explain the formation... of experiments in which varying time was used, 44 Eh c CO o a •H Eh «.H O +> O

  4. Treatment and prevention systems for acid mine drainage and halogenated contaminants

    DOE Patents [OSTI]

    Jin, Song (Fort Collins, CO); Fallgren, Paul H. (Laramie, WY); Morris, Jeffrey M. (Laramie, WY)

    2012-01-31T23:59:59.000Z

    Embodiments include treatments for acid mine drainage generation sources (10 perhaps by injection of at least one substrate (11) and biologically constructing a protective biofilm (13) on acid mine drainage generation source materials (14). Further embodiments include treatments for degradation of contaminated water environments (17) with substrates such as returned milk and the like.

  5. Remedial extraction and catalytic hydrodehalogenation for treatment of soils contaminated by halogenated hydrophobic organic compounds

    E-Print Network [OSTI]

    Wee, Hun Young

    2009-05-15T23:59:59.000Z

    for the extraction of 1,2,4,5-tetrachlorobenzne (TeCB) or pentachlorophenol (PCP) from contaminated soil. Palladium-catalyzed hydrodehalogenation (HDH) was applied for destroying TeCB or PCP in mixtures of water and ethanol in a batch mode. The experimental results...

  6. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    105, 24191–24204, 2000. Allan, B. J. , Plane J. M. C. , andlayer, Geophys. Res. Lett. , Allan, J. D. , Topping, D. O. ,1,2 , G. McFiggans 3 , J. D. Allan 3,4 , A. R. Baker 5 , S.

  7. Supramolecular self-assembled network formation containing NBr halogen bonds in physisorbed overlayers

    E-Print Network [OSTI]

    Brewer, Adam Y.; Sacchi, Marco; Parker, Julia E.; Truscott, Chris L.; Jenkins, Steve; Clarke, Stuart M.

    2014-08-05T23:59:59.000Z

    adsorbed on graphite, Mol. Phys., 1991, 72, 395-411. 24 A. Inaba, H. Chihara, S. M. Clarke and R. K. Thomas, The structure and heat capacity of fluoromethane monolayers adsorbed on graphite, Mol. Phys., 1991, 72, 109-120. 25 R. Gutzler, O. Ivasenko, C... . This sharp transition is indicative of a mixed co-layer (rather than solid solution) that underwent incongruent melting to form crystalline BPY and liquid DBTFB, with a melting point of ~275 K. This compares with the bulk melting point of 383 – 388 K 35...

  8. Analysis and Characterization of Halogenated Transformation Products of Pharmaceuticals and Personal Care Products in Wastewater Effluent

    E-Print Network [OSTI]

    Bulloch, Daryl Neil

    2013-01-01T23:59:59.000Z

    wastewater contaminants in biosolids destined for landin water, soil, sediment, and biosolids by HPLC/MS/MS. 2007,the organic carbon content of biosolids in wastewater can

  9. Investigating the biosynthesis of halogenated meroterpenoid natural products from marine actinomycetes

    E-Print Network [OSTI]

    Winter, Jaclyn Marie

    2010-01-01T23:59:59.000Z

    following conditions: 40 ml of 20% acetonitrile:water, 60ml of 40% acetonitrile:water, 60ml of 60% acetonitrile:water, 60 ml of 80% acetonitrile:

  10. Investigating the Biosynthesis of Halogenated Meroterpenoid Natural Products from Marine Actinomycetes

    E-Print Network [OSTI]

    Winter, Jaclyn Marie

    2010-01-01T23:59:59.000Z

    following conditions: 40 ml of 20% acetonitrile:water, 60ml of 40% acetonitrile:water, 60ml of 60% acetonitrile:water, 60 ml of 80% acetonitrile:

  11. Halogen-Based Plasma Etching of Novel Field-Effect Transistor Gate Materials

    E-Print Network [OSTI]

    Kiehlbaugh, Kasi Michelle

    2009-01-01T23:59:59.000Z

    Factorial Design .in the fractional factorial design Table 2: Design matrixetch data from the full factorial design, including starting

  12. Analysis and Characterization of Halogenated Transformation Products of Pharmaceuticals and Personal Care Products in Wastewater Effluent

    E-Print Network [OSTI]

    Bulloch, Daryl Neil

    2013-01-01T23:59:59.000Z

    and biological treatments for wastewater decontamination- Atreatment involves biological degradation of organic wastewaterBiological effects of transformation products. The extent of attenuation of PPCPs through wastewater treatment

  13. Odor representations in olfactory cortex

    E-Print Network [OSTI]

    Poo, Cindy

    2010-01-01T23:59:59.000Z

    influence on olfactory bulb activity in the rabbit. Brainin the olfactory bulb accelerates odor discrimination inexcitation of olfactory bulb granule cells. J Neurosci 27,

  14. Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivity

    E-Print Network [OSTI]

    Berke, Allison Paige

    2013-01-01T23:59:59.000Z

    representations in the olfactory bulb revealed using aof single olfactory bulb neurons to binary mixtures of aminoin the mouse olfactory bulb. Nature, 450(7169), 503–508.

  15. Studies on the Cave- Spider Family Leptonetidae

    E-Print Network [OSTI]

    Ledford, Joel M.

    2011-01-01T23:59:59.000Z

    105. Prolateral; 106. Bulb, prolateral; 107. Accessory81. Prolateral; 82. Bulb, retrolateral; 83. Accessory87. Prolateral; 88. Bulb, retrolateral; 89. Accessory

  16. Using Building Simulation and Optimization to Calculate Lookup Tables for Control

    E-Print Network [OSTI]

    Coffey, Brian

    2012-01-01T23:59:59.000Z

    Merced 106 Monthly average wet bulb temperature and tanktemp versus minium wet bulb temp 98 Detailed slices ofmaximum overnight wet bulb temperatures). PhD Dissertation,

  17. Using Building Simulation and Optimization to Calculate Lookup Tables for Control

    E-Print Network [OSTI]

    Coffey, Brian

    2011-01-01T23:59:59.000Z

    Merced 106 Monthly average wet bulb temperature and tanktemp versus minium wet bulb temp 98 Detailed slices ofand maximum overnight wet bulb temperatures). Figure 8:

  18. "Hot" for Warm Water Cooling

    E-Print Network [OSTI]

    Coles, Henry

    2012-01-01T23:59:59.000Z

    Format Locations sorted by Dry Bulb Temperature Locationssorted by Wet Bulb Temperature 11. APPENDIX C: DIRECT LIQUIDis constrained by outdoor wet bulb temperature) or dry

  19. Vortices in brain activity: Their mechanism and significance for perception

    E-Print Network [OSTI]

    Freeman, Walter J III

    2009-01-01T23:59:59.000Z

    of the main olfactory bulb in adult rats. Neuroscience, 64,apex rabbit olfactory bulb rabbit visual cortex phaseoutline of the olfactory bulb, on which is superimposed a 4

  20. How to upgrade your incandescent light bulbs Many people are choosing replacements for their standard incandescent light bulbs to save money or energy, because they've heard of new LED

    E-Print Network [OSTI]

    Bystroff, Chris

    or building a new home, work wi efficient light fixture, · use occupancy or vacancy sensors, or · if you are renovating your home

  1. China Energy Efficiency Round Robin Testing Results for Room Air Conditioners

    E-Print Network [OSTI]

    Zhou, Nan

    2010-01-01T23:59:59.000Z

    C Dry bulb. air inlet. indoor side ºC Wet bulb. air inlet.indoor side ºC Dry bulb. air outlet.indoor side ºC Wet bulb. air outlet. indoor side ºC

  2. Comparisons of HVAC Simulations between EnergyPlus and DOE-2.2 for Data Centers

    E-Print Network [OSTI]

    Hong, Tianzhen

    2009-01-01T23:59:59.000Z

    cooling capacity as a function of outside dry-bulb (ODB) andentering wet-bulb temperatures (EWB), the EIR(EWB,ODB):as a function of outside dry-bulb and entering wet-bulb

  3. 56903Federal Register / Vol. 75, No. 180 / Friday, September 17, 2010 / Rules and Regulations rule does not impose any enforceable

    E-Print Network [OSTI]

    the commodities Garlic, bulb and Shallot, bulb; revise the commodities Onion, bulb; Onion, green; and Vegetable.13 * * * * * Melon, subgroup 9A ...................... 0.10 * * * * * Okra ...................... 0.10 Onion, bulb

  4. STAT 472 F14 Chapter 4 Homework.pdf

    E-Print Network [OSTI]

    Owner

    2014-09-30T23:59:59.000Z

    Sep 30, 2014 ... The hotel has 10,000 light bulbs. The light bulbs are all new. If a replacement bulb burns out, it too will be replaced with a new bulb. You are ...

  5. Secreted factors from olfactory mucosa cells expanded as free-floating spheres increase neurogenesis in olfactory bulb neurosphere cultures

    E-Print Network [OSTI]

    Barraud, Perrine; He, Xiao-ling; Caldwell, Maeve; Franklin, Robin J M

    2008-02-18T23:59:59.000Z

    ) containing Dulbecco's Modified Eagle Medium (DMEM; Gibco) prior to mechanical disso- ciation to a cell suspension. Remaining cell aggregates were removed after filtration through a 40 µm cell strainer (BD Falcon) and cell numbers were estimated using...

  6. 2008 Joint Appendices JA2-1 Appendix JA2 Reference Weather/Climate Data

    E-Print Network [OSTI]

    weather file contains data on a variety of ambient conditions such as: · Dry bulb temperature · Wet bulb

  7. EPI-FLUORESCENCE ATTACHMENT f o r I n v e r t e d M i c r o s c o p e D I A P H O T -T M D

    E-Print Network [OSTI]

    Kleinfeld, David

    . In exchanging the lamp bulb, do not touch the glass part of the lamp bulb with bare hands. Dust, dirt or finger marks on the bulb surface should be wiped with alcohol. For attaching the mercury lamp bulb to the socket, take note of the polarity of the bulb. Before lighting the lamp, confirm that the lamp bulb

  8. Student Directions Student Directions: Using your homework from "Building a Fancy Spectrograph" fill in the

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Incandescent Bulb Incandescent Bulb Florescent Bulb #12;_________________________________________________________________________________ 7. How does the spectrum from the frosted bulb compare to that of the unfrosted bulb? 8. From number 7, what can you conclude about the material that makes the bulb "frosted?" 9. How is the florescent

  9. MATH 56A SPRING 2008 STOCHASTIC PROCESSES

    E-Print Network [OSTI]

    Igusa, Kiyoshi

    that it starts at the end of the previous process). I used the example of a light bulb. You put a light bulb replaced by a new bulb. Each bulb is independent of the previous one. Some numbers associated considered three kinds of light bulbs: (1) The guaranteed light bulb which will last exactly 1000 hours. (2

  10. MATH 56A SPRING 2008 STOCHASTIC PROCESSES

    E-Print Network [OSTI]

    Igusa, Kiyoshi

    at the end of the previous process). I used the example of a light bulb. You put a light bulb into a socket by a new bulb. Each bulb is independent of the previous one. Some numbers associated to this process are kinds of light bulbs: (1) The guaranteed light bulb which will last exactly 1000 hours. (2) The Poisson

  11. University of Akron March 21, 2013 Physics 262: Physics for Life Sciences II

    E-Print Network [OSTI]

    Hu, Ben Yu-Kuang

    electroscope bulb, causing the needle to deflect. What is the net charge on the bulb and on the needle? (A) Positive on the bulb, negative on the needle. (B) Negative on the bulb, positive on the needle. (C) Positive on both the bulb and the needle. (D) Negative on both the bulb and the needle. 3. A solid

  12. Pheromone transduction in the vomeronasal organ Emily R Liman

    E-Print Network [OSTI]

    Liman, Emily

    bulb (AOB), whereas the OE projects to the olfactory bulb (OB). (b) In a section taken at the position- to the accessory olfactory bulb and to the main olfactory bulb, respectively. The accessory olfactory bulb, unlike the main olfactory bulb or relay nuclei of other sensory organs, does not project to the cortex. Instead

  13. Coulomb corrected eikonal description of the breakup of halo nuclei

    E-Print Network [OSTI]

    P. Capel; D. Baye; Y. Suzuki

    2008-10-15T23:59:59.000Z

    The eikonal description of breakup reactions diverges because of the Coulomb interaction between the projectile and the target. This divergence is due to the adiabatic, or sudden, approximation usually made, which is incompatible with the infinite range of the Coulomb interaction. A correction for this divergence is analysed by comparison with the Dynamical Eikonal Approximation, which is derived without the adiabatic approximation. The correction consists in replacing the first-order term of the eikonal Coulomb phase by the first-order of the perturbation theory. This allows taking into account both nuclear and Coulomb interactions on the same footing within the computationally efficient eikonal model. Excellent results are found for the dissociation of 11Be on lead at 69 MeV/nucleon. This Coulomb Corrected Eikonal approximation provides a competitive alternative to more elaborate reaction models for investigating breakup of three-body projectiles at intermediate and high energies.

  14. Rubidium in Metal-Deficient Disk and Halo Stars

    E-Print Network [OSTI]

    Jocelyn Tomkin; David L. Lambert

    1999-05-13T23:59:59.000Z

    We report the first extensive study of stellar Rb abundances. High-resolution spectra have been used to determine, or set upper limits on, the abundances of this heavy element and the associated elements Y, Zr, and Ba in 44 dwarfs and giants with metallicities spanning the range -2.0 <[Fe/H] < 0.0. In metal-deficient stars Rb is systematically overabundant relative to Fe; we find an average [Rb/Fe] of +0.21 for the 32 stars with [Fe/H] < -0.5 and measured Rb. This behavior contrasts with that of Y, Zr, and Ba, which, with the exception of three new CH stars (HD 23439A and B and BD +5 3640), are consistently slightly deficient relative to Fe in the same stars; excluding the three CH stars, we find the stars with [Fe/H] < -0.5 have average [Y/Fe], [Zr/Fe], and [Ba/Fe] of --0.19 (24 stars), --0.12 (28 stars), and --0.06 (29 stars), respectively. The different behavior of Rb on the one hand and Y, Zr, and Ba on the other can be attributed in part to the fact that in the Sun and in these stars Rb has a large r-process component while Y, Zr, and Ba are mostly s-process elements with only small r-process components. In addition, the Rb s-process abundance is dependent on the neutron density at the s-processing site. Published observations of Rb in s-process enriched red giants indicate a higher neutron density in the metal-poor giants. These observations imply a higher s-process abundance for Rb in metal-poor stars. The calculated combination of the Rb r-process abundance, as estimated for the stellar Eu abundances, and the s-process abundance as estimated for red giants accounts satisfactorily for the observed run of [Rb/Fe] with [Fe/H].

  15. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    calculations, it was predicted that at typical plasma reactorof calculation. The etch rate of HfO 2 in this reactor at -calculation to be valid, it must also be assumed that at the operating conditions of the ICP reactor,

  16. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    model for Si etching by fluorocarbon plasmas." Journal Ofwith inductively coupled fluorocarbon plasmas." Journal ofwith inductively coupled fluorocarbon plasmas." Journal of

  17. Recovery of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from Ralstonia eutropha cultures with non-halogenated solvents

    E-Print Network [OSTI]

    Riedel, Sebastian L.

    Reduced downstream costs, together with high purity recovery of polyhydroxyalkanoate (PHA), will accelerate the commercialization of high quality PHA-based products. In this work, a process was designed for effective ...

  18. Environ. Sci. Technol. M92, 26,2454-2461 In-Situ Transformation of Carbon Tetrachloride and Other Halogenated

    E-Print Network [OSTI]

    Semprini, Lewis

    Environ. Sci. Technol. M92, 26,2454-2461 In-Situ Transformation of Carbon Tetrachloride and Other, California 94305-4020 Enhanced in-situ transformation of carbon tetrachloride (CT) was observed under anoxic Chlorinated aliphatic hydrocarbons (CAHs)with one or two carbon atoms are widely used as solvents, degreasing

  19. Fluids and halogens at the diagenetic-metamorphic boundary: evidence from veins in continental basins, western Norway

    E-Print Network [OSTI]

    Banks, David

    basins, western Norway H. SVENSEN1 , B. JAMTVEIT1 , D. A. BANKS2 AND D. KARLSEN1 1 Department of Geology, University of Oslo, Blindern, Oslo, Norway; 2 School of Earth Sciences, University of Leeds, Leeds, UK, Kvamshesten and Solund basins) in western Norway. These include calcite-, quartz- and epidote-dominated veins

  20. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    initialize(int part_type,double enrgy) int j; type =part_type; energy = enrgy; //coutenrgy, double Ion_yield[NO_ION_

  1. Kinetic model for predicting the concentrations of active halogens species in chlorinated saline cooling waters. Final report

    SciTech Connect (OSTI)

    Haag, W.R.; Lietzke, M.H.

    1981-08-01T23:59:59.000Z

    A kinetic model has been developed for describing the speciation of chlorine-produced oxidants in seawater as a function of time. The model is applicable under a broad variety of conditions, including all pH range, salinities, temperatures, ammonia concentrations, organic amine concentrations, and chlorine doses likely to be encountered during power plant cooling water chlorination. However, the effects of sunlight are not considered. The model can also be applied to freshwater and recirculating water systems with cooling towers. The results of the model agree with expectation, however, complete verification is not feasible at the present because analytical methods for some of the predicted species are lacking.

  2. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    C. , Chang, J.P. , “Feature Profile Evolution: From Plasmasurface kinetics and feature profile evolution in chlorineet al. (2008). "Feature profile evolution during shallow

  3. Body burdens of brominated flame retardants and other persistent organo-halogenated compounds and their descriptors in US girls

    SciTech Connect (OSTI)

    Windham, Gayle C., E-mail: gayle.windham@cdph.ca.gov [CA Department of Public Health, DEODC, 850 Marina Bay Pkwy, Bldg. P, Richmond, CA 94804 (United States); Pinney, Susan M. [University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States)] [University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States); Sjodin, Andreas [Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)] [Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States); Lum, Raymond [Impact Assessment Inc., San Diego, CA (United States)] [Impact Assessment Inc., San Diego, CA (United States); Jones, Richard S.; Needham, Larry L. [Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)] [Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States); Biro, Frank M. [University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States)] [University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States); Hiatt, Robert A. [University of California Medical School, San Francisco, CA (United States)] [University of California Medical School, San Francisco, CA (United States); Kushi, Lawrence H. [Kaiser Permanente Northern California, Oakland, CA 94612 (United States)] [Kaiser Permanente Northern California, Oakland, CA 94612 (United States)

    2010-04-15T23:59:59.000Z

    Background: Levels of brominated flame retardants are increasing in US populations, yet little data are available on body burdens of these and other persistent hormonally active agents (HAAs) in school-aged children. Exposures to such chemicals may affect a number of health outcomes related to development and reproductive function. Objective: Determine the distribution of biomarkers of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organo-chlorinated pesticides (OCPs), such as DDT/DDE, in children, and their variation by key descriptor variables. Methods: Ethnically diverse cohorts of girls 6-8 y old at baseline are being followed for growth and pubertal development in a multi-site, longitudinal study. Nearly 600 serum samples from the California and Ohio sites were analyzed for lipids, 35 PCB congeners, 11 PBDE congeners, and 9 OCPs. The biomarker distributions were examined and geometric means compared for selected analytes across categories of age, race, site, body mass index (BMI), parental education, maternal age at delivery, and breast feeding in adjusted models. Results: Six PBDE congeners were detected among greater than 70% of samples, with BDE-47 having the highest concentration (median 42.2, range 4.9-855 ng/g lipid). Girls in California had adjusted geometric mean (GM) PBDE levels significantly higher than girls in Ohio. Furthermore, Blacks had significantly higher adjusted GMs of all six PBDE congeners than Whites, and Hispanics had intermediate values. GMs tended to be lower among more obese girls, while other variables were not strongly associated. In contrast, GMs of the six PCB congeners most frequently detected were significantly lower among Blacks and Hispanics than Whites. PCBs and the three pesticides most frequently detected were also consistently lower among girls with high BMI, who were not breast-fed, whose mothers were younger, or whose care-givers (usually parents) were less educated. Girls in California had higher GMs than in Ohio for the pesticides and most PCB congeners, but the opposite for CB-99 and -118. Conclusions: Several of these potential HAAs were detected in nearly all of these young girls, some at relatively high levels, with variation by geographic location and other demographic factors that may reflect exposure pathways. The higher PBDE levels in California likely reflect differences in fire regulation and safety codes, with potential policy implications.

  4. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    Fit”. 2) Press “Normal fit” several time until the resultfinal.mat (Cauchy fit) 2. Fit 1) Press “Window” and select “thickness. Check the “Fit” box, and press “OK”. 2. For

  5. Experimental and Computational Study of Flame Inhibition Mechanisms of Halogenated Compounds in C1-C3 Alkanes Flames

    E-Print Network [OSTI]

    Osorio Amado, Carmen H

    2013-07-30T23:59:59.000Z

    suppressants on ignition and laminar flame propagation of C_(1)-C_(3) alkanes premixed mixtures, as good representatives of flammable gas fires (Class B fires). This methodology integrates model formulations and experimental designs in order to examine both...

  6. Gas Phase Reactions between Fuel Molecules and Halogens: A Review of the Reaction between Atomic Chlorine and Ammonia

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.Newof EnergyFunding OpportunityF GGary M. MignognaEstimatesGas

  7. University of Akron March 29, 2012 Physics 262: Physics for Life Sciences II

    E-Print Network [OSTI]

    Hu, Ben Yu-Kuang

    ) the bulb of an initially electri- cally neutral electroscope, so that the pointer of the electroscope rises (Step 1). Keeping the rod near the bulb, I then ground the elec- troscope by touching the bulb, which on the bulb and the pointer of the electroscope? (A) Both the bulb and pointer have net positive charge. (B

  8. Institute for Software Technology Wissensverarbeitung

    E-Print Network [OSTI]

    Motivation Example correct behavior battery(c)(ab(c)voltage(c))battery(c)(ab(c)voltage(c)) bulb for Software Technology Motivation Example cont. t t tsystem structure battery(B). bulb(L1). bulb(L2). bulb(L3 the fact that a bulb does not lit if it is broken · solution: model faulty behavior battery

  9. Instructions for use of the Cannon-Fenske Opaque Viscometer 1. In a separate container filter the test sample

    E-Print Network [OSTI]

    Saskatchewan, University of

    . When the liquid begins to fill bulb B, stop the flow by plugging tube A. 4. Allow approximately 10 the efflux time for bulb C times the constant for the lower bulb using Equation 1. 7. Check the results by repeating step 6 for bulb D, using the upper bulb constant in Equation 2. LcCtv =1 (1) UDCtv =2 (2) Where: 1

  10. Development and Use of a Feedback Control System in Introducing Biotechnology Students to

    E-Print Network [OSTI]

    Allen, Gale

    departments at MSU Mankato. The air temperature near a small light bulb was controlled while the variables on the performance of the control loop. The air temperature near the bulb was monitored with a thermocouple producing conditioning amplifier Light bulb voltage driver Thermocouple and 12V automobile light bulb Light Bulb Driver

  11. ILD 12 Name: _____________________ Working out what a model implies: Images

    E-Print Network [OSTI]

    Maryland at College Park, University of

    . If you know the rays all come from a single light bulb, where would you guess that the bulb is located of the bulb. Where would you guess the bulb is located? What could be behind the screen? Situation 3: You now have a converging lens. A light bulb is positioned a distance larger than the focal length to the left

  12. M. Bahrami ENSC 461 (S 11) Gas Vapor Mixtures and HVAC 1 Gas Vapor Mixtures and HVAC

    E-Print Network [OSTI]

    Bahrami, Majid

    = ha + hg Dry Bulb Temperature Tdb: the temperature measured by a thermometer placed in a mixture wet bulb temperature and the other dry bulb temperature. Tdb and Twb are sufficient to fix the state where 22 2 2 622.0 g g PP P since %1002 . Note that T2 is the wet-bulb temperature Twb. Wet Bulb

  13. Energy efficient synthesis of boranes

    DOE Patents [OSTI]

    Thorn, David L (Los Alamos, NM); Tumas, William (Los Alamos, NM); Schwarz, Daniel E (Los Alamos, NM); Burrell, Anthony K (Los Alamos, NM)

    2012-01-24T23:59:59.000Z

    The reaction of halo-boron compounds (B--X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B--H compounds, compounds having one or more B--H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si--H) react with B--X compounds to form B--H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface-bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn--H bond) to form boranes and halostannanes (tin compounds having a Sn--X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCl.sub.3, the B--H compound is B.sub.2H.sub.6, and where the reducing potential is provided electrochemically or by the thermolysis of formate.

  14. Energy efficient synthesis of boranes

    DOE Patents [OSTI]

    Thorn, David L. (Los Alamos, NM); Tumas, William (Los Alamos, NM); Schwarz, Daniel E. (Los Alamos, NM); Burrell, Anthony K. (Los Alamos, NM)

    2010-11-23T23:59:59.000Z

    The reaction of halo-boron compounds (B--X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B--H compounds, compounds having one or more B--H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si--H) react with B--X compounds to form B--H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface-bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn--H bond) to form boranes and halostannanes (tin compounds having a Sn--X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCl.sub.3, the B--H compound is B.sub.2H.sub.6, and where the reducing potential is provided electrochemically or by the thermolysis of formate.

  15. Polarity regulation during neuronal migration and differentiation

    E-Print Network [OSTI]

    Higginbotham, Holden Richard

    2008-01-01T23:59:59.000Z

    neurons in the rat olfactory bulb. An immunohistochemicalof the rat main olfactory bulb. Neurosci Res. 23:73-88.a repellent for olfactory bulb axons. Cell. 96:807-18. Li,

  16. PERFORMANCE OF RESIDENTIAL AIR-TO-AIR HEAT EXCHANGERS: TEST METHODS AND RESULTS

    E-Print Network [OSTI]

    Fisk, William J.

    2013-01-01T23:59:59.000Z

    14. Thermometer, Precision, 0.1oc Subdivision, Dry Bulb 15.Thermocouple, 30 gauge, Copper-Constantan, Dry Bulb 16.O.l°C Subdivisions, Wet Bulb 17. Thermocouple, 30 gauge,

  17. Role of the broadly expressed olfactory receptor OlfCc1 in mediating amino acid detection in Zebrafish

    E-Print Network [OSTI]

    DeMaria, Shannon Nicole

    2010-01-01T23:59:59.000Z

    in the mouse olfactory bulb. Nature, 419(6904), 296-300.Axons in the Main Olfactory Bulb. J. Neurosci. , Conzelmann,in the accessory olfactory bulb. Neuron, Dynes, J.L. & Ngai,

  18. Understanding Perception Through Neural 'Codes'

    E-Print Network [OSTI]

    Freeman, Walter J III

    2011-01-01T23:59:59.000Z

    stage, the olfactory bulb, and excite mitral (pyramidal)1.89 m/s in the olfactory bulb, 2-4 m/s in neocortex) thatextend over the whole bulb. I infer that the correlation

  19. A NEUROBIOLOGICAL MODEL OF PERCEPTION Considerations for Transference

    E-Print Network [OSTI]

    Pincus, David; Freeman, Walter J III; Modell, Arnold

    2007-01-01T23:59:59.000Z

    outermost layer of the synaptic bulb. The world never “getsthe level of the olfactory bulb, and it is here that thelevel of the olfactory bulb, thus resulting in an unlimited

  20. Chaotic neocortical dynamics.

    E-Print Network [OSTI]

    Freeman, Walter J III

    2013-01-01T23:59:59.000Z

    glomeruli of olfactory bulb on paired shock stimulation.mal seizure spikes in olfactory bulb and cortex caused byneurons in the olfactory bulb (a KIe set, Freeman and Erwin,