Sample records for type binary owner

  1. br Owner br Facility br Type br Capacity br MW br Commercial br Online

    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 YouKizildere IRaghuraji Agro IndustriesTownDells, Wisconsin: EnergyWyandanch,Eaga SolarZolo Technologies IncusgbcblackOwner

  2. br Owner br Facility br Type br Capacity br MW br Commercial...

    Open Energy Info (EERE)

    Facility br Type br Capacity br MW br Commercial br Online br Date br Geothermal br Area br Geothermal br Region Coordinates Ahuachapan Geothermal Power Plant LaGeo SA de CV Single...

  3. Facility Name Facility Name Facility FacilityType Owner Developer EnergyPurchaser

    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 directedAnnualPropertyd8c-a9ae-f8521cbb8489 NoEurope BV Jump to:FASFMI-HDFRED Type Term Title

  4. A Type System for Certified Binaries Zhong Shao Bratin Saha Valery Trifonov Nikolaos Papaspyrou

    E-Print Network [OSTI]

    Trifonov, Valery

    A Type System for Certified Binaries Zhong Shao Bratin Saha Valery Trifonov Nikolaos Papaspyrou Department of Computer Science, Yale University New Haven, CT 06520-8285, U.S.A. {shao, saha, trifonov

  5. RADIAL VELOCITIES OF GALACTIC O-TYPE STARS. II. SINGLE-LINED SPECTROSCOPIC BINARIES

    SciTech Connect (OSTI)

    Williams, S. J.; Gies, D. R. [Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106 (United States); Hillwig, T. C. [Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383 (United States); McSwain, M. V. [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 (United States); Huang, W., E-mail: swilliams@chara.gsu.edu, E-mail: gies@chara.gsu.edu, E-mail: todd.hillwig@valpo.edu, E-mail: mcswain@lehigh.edu, E-mail: hwenjin@astro.washington.edu [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)

    2013-02-01T23:59:59.000Z

    We report on new radial velocity measurements of massive stars that are either suspected binaries or lacking prior observations. This is part of a survey to identify and characterize spectroscopic binaries among O-type stars with the goal of comparing the binary fraction of field and runaway stars with those in clusters and associations. We present orbits for HDE 308813, HD 152147, HD 164536, BD-16 Degree-Sign 4826, and HDE 229232, Galactic O-type stars exhibiting single-lined spectroscopic variation. By fitting model spectra to our observed spectra, we obtain estimates for effective temperature, surface gravity, and rotational velocity. We compute orbital periods and velocity semiamplitudes for each system and note the lack of photometric variation for any system. These binaries probably appear single-lined because the companions are faint and because their orbital Doppler shifts are small compared to the width of the rotationally broadened lines of the primary.

  6. Radial Velocities of Galactic O-Type Stars. II. Single-lined Spectroscopic Binaries

    E-Print Network [OSTI]

    Williams, S J; Hillwig, T C; McSwain, M V; Huang, W

    2012-01-01T23:59:59.000Z

    We report on new radial velocity measurements of massive stars that are either suspected binaries or lacking prior observations. This is part of a survey to identify and characterize spectroscopic binaries among O-type stars with the goal of comparing the binary fraction of field and runaway stars with those in clusters and associations. We present orbits for HDE 308813, HD 152147, HD 164536, BD-16 4826 and HDE 229232, Galactic O-type stars exhibiting single-lined spectroscopic variation. By fitting model spectra to our observed spectra we obtain estimates for effective temperature, surface gravity, and rotational velocity. We compute orbital periods and velocity semiamplitudes for each system and note the lack of photometric variation for any system. These binaries probably appear single-lined because the companions are faint and because their orbital Doppler shifts are small compared to the width of the rotationally broadened lines of the primary.

  7. "Table HC3.5 Space Heating Usage Indicators by Owner-Occupied...

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

    5 Space Heating Usage Indicators by Owner-Occupied Housing Unit, 2005" " Million U.S. Housing Units" ,," Owner-Occupied Housing Units (millions)","Type of Owner-Occupied Housing...

  8. S-Type and P-Type Habitability in Stellar Binary Systems: A Comprehensive Approach. I. Method and Applications

    E-Print Network [OSTI]

    Cuntz, Manfred

    2013-01-01T23:59:59.000Z

    A comprehensive approach is provided to the study of both S-type and P-type habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in case of S-type orbits the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) The consideration of a joint constraint including orbital stability and a habitable environment for a putative system planet through the stellar radiative energy fluxes ("radiative habitable zone"; RHZ) needs to be met. (2) The treatment of conservative, general and extended zones of habitability for the various systems as defined for the Solar System and beyond. (3) The providing of a combined formalism for the assessment of both S-type and P-type habitability; in particular, mathematical criteria are presented for which kind of system S-type ...

  9. PHOTOMETRIC PROPERTIES FOR SELECTED ALGOL-TYPE BINARIES. V. V1241 TAURI

    SciTech Connect (OSTI)

    Yang, Y.-G.; Dai, H.-F. [School of Physics and Electronic Information, Huaibei Normal University, 235000 Huaibei, Anhui Province (China); Zhang, X.-B.; Li, H.-L., E-mail: yygcn@163.com [National Astronomical Observatories, Chinese Academy of Sciences, 100012 Beijing (China)

    2012-11-01T23:59:59.000Z

    We present new photometry for the eclipsing binary V1241 Tau, which was obtained on six nights between 2011 December and 2012 January using the 85 cm telescope at the Xinglong station of the National Astronomical Observatories of China. By using the updated Wilson-Devinney code, photometric models with third lights were deduced from two sets of light curves. The result implies that V1241 Tau is an Algol-type near-contact binary (NCB), whose mass ratio and filling-out of the primary are q = 0.545 ({+-} 0.003) and f{sub 1} = 82.4% ({+-} 0.2%), respectively. Based on all available times of minimum light spanning over 80 yr, the O - C curve of V1241 Tau appears to show a quasi-sinusoidal oscillation, i.e., a light-time orbit. The modulated period and amplitude are P{sub mod} = 47.4 ({+-} 1.7) yr and A = 0.0087 ({+-} 0.0005) days, respectively. This kind of period variation may be more likely attributed to the light-time effect via a presence of an unseen third body. From an analysis of 23 Algol-type NCBs with EB-type light curves, we determine that the fill-out for the primary f{sub 1} will increase as the orbital period P decreases. With angular momentum loss, the orbit of the binary will shrink, which causes f{sub 1} to increase. The primary component finally fills its Roche lobe, and the binary evolves into contact configuration. Therefore, this kind of Algol-type NCB with EB-type light curves, such as V1241 Tau, may be a progenitor of the A-type W UMa binary.

  10. Observational Properties of Type Ib/c Supernova Progenitors in Binary Systems

    E-Print Network [OSTI]

    Kim, Hyun-Jeong; Koo, Bon-Chul

    2015-01-01T23:59:59.000Z

    In several recent observational studies on Type Ib/c supernovae (SNe Ib/c), the inferred ejecta masses have a peak value of 2.0 -- 4.0 $M_\\odot$, in favor of the binary scenario for their progenitors rather than the Wolf-Rayet star scenario. To investigate the observational properties of relatively low-mass helium stars in binary systems as SN Ib/c progenitors, we constructed atmospheric models with the non-LTE radiative transfer code CMFGEN, using binary star evolution models. We find that these helium stars can be characterized by relatively narrow helium emission lines if the mass-loss rate during the final evolutionary phase is significantly enhanced as implied by many SN Ib/c observations. The optical brightness of helium star progenitors can be meaningfully enhanced with a strong wind for $M \\gtrsim 4.4 M_\\odot$, but hardly affected or slightly weakened for relatively low-mass of $\\sim 3.0 M_\\odot$, compared to the simple estimate using blackbody approximation. We further confirm the previous suggestion...

  11. The massive double-lined O-type binary HD 165052

    E-Print Network [OSTI]

    J. I. Arias; N. I. Morrell; R. H. Barba; G. L. Bosch; M. Grosso; M. Corcoran; .

    2002-05-07T23:59:59.000Z

    We present a new optical spectroscopic study of the O-type binary HD 165052 based on high- and intermediate-resolution CCD observations. We re-investigated the spectral classification of the binary components, obtaining spectral types of O6.5 V and O7.5 V for the primary and secondary, respectively, finding that both stars display weak C {\\sc iii} $\\lambda5696$ emission in their spectra. We also determined a radial-velocity orbit for HD 165052 with a period of 2.95510 $\\pm$ 0.00001 d, and semiamplitudes of 94.8 and 104.7 $\\pm$ 0.5 km s$^{-1}$, resulting in a mass ratio $Q = 0.9$. From a comparison with previous radial-velocity determinations, we found evidence of apsidal motion in the system. Several signatures of wind-wind collision, such as phase-locked variability of the X-ray flux and the Struve-Sahade effect, are also considered. It was also found that the reddening in the region should be normal, in contrast with previous determinations.

  12. Distinguishing types of compact-object binaries using the gravitational-wave signatures of their mergers

    E-Print Network [OSTI]

    Ilya Mandel; Carl-Johan Haster; Michal Dominik; Krzysztof Belczynski

    2015-05-04T23:59:59.000Z

    We analyze the distinguishability of populations of coalescing binary neutron stars, neutron-star black-hole binaries, and binary black holes, whose gravitational-wave signatures are expected to be observed by the advanced network of ground-based interferometers LIGO and Virgo. We consider population-synthesis predictions for plausible merging binary distributions in mass space, along with measurement accuracy estimates from the main gravitational-wave parameter-estimation pipeline. We find that for our model compact-object binary mass distribution, we can always distinguish binary neutron stars and black-hole--neutron-star binaries, but not necessarily black-hole--neutron-star binaries and binary black holes; however, with a few tens of detections, we can accurately identify the three subpopulations and measure their respective rates.

  13. A Type System for Certified Binaries Zhong Shao Bratin Saha Valery Trifonov Nikolaos Papaspyr*

    E-Print Network [OSTI]

    for Certified Binaries Zhong Shao Bratin Saha Valery Trifonov Nikolaos Papaspyr* *ou.S.A. {shao, saha, trifonov, nickie}@cs.yale.edu Abstract ever, none

  14. Wind-driven evolution of white dwarf binaries to type Ia supernovae

    SciTech Connect (OSTI)

    Ablimit, Iminhaji; Xu, Xiao-jie; Li, X.-D. [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2014-01-01T23:59:59.000Z

    In the single-degenerate scenario for the progenitors of Type Ia supernovae (SNe Ia), a white dwarf rapidly accretes hydrogen- or helium-rich material from its companion star and appears as a supersoft X-ray source. This picture has been challenged by the properties of the supersoft X-ray sources with very low mass companions and the observations of several nearby SNe Ia. It has been pointed out that the X-ray radiation or the wind from the accreting white dwarf can excite winds or strip mass from the companion star, thus significantly influencing the mass transfer processes. In this paper, we perform detailed calculations of the wind-driven evolution of white dwarf binaries. We present the parameter space for the possible SN Ia progenitors and for the surviving companions after the SNe. The results show that the ex-companion stars of SNe Ia have characteristics more compatible with the observations, compared with those in the traditional single-degenerate scenario.

  15. Business Owners: Prepare for Utility Disruptions | Department...

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

    Utility Disruptions Business Owners: Prepare for Utility Disruptions Business Owners: Prepare for Utility Disruptions Have a plan in place in case a natural disaster or other...

  16. iPTF13bvn: The first evidence of a binary progenitor for a type Ib supernova

    SciTech Connect (OSTI)

    Bersten, Melina C.; Folatelli, Gast髇; Nomoto, Ken'ichi; Quimby, Robert [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Benvenuto, Omar G. [Facultad de Ciencias Astron髆icas y Geof韘icas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA La Plata (Argentina); Kuncarayakti, Hanindyo [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Srivastav, Shubham; Anupama, G. C.; Sahu, Devendra K., E-mail: melina.bersten@ipmu.jp [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India)

    2014-10-01T23:59:59.000Z

    The recent detection in archival Hubble Space Telescope images of an object at the location of supernova (SN) iPTF13bvn may represent the first direct evidence of the progenitor of a Type Ib SN. The object's photometry was found to be compatible with a Wolf-Rayet pre-SN star mass of ?11 M {sub ?}. However, based on hydrodynamical models, we show that the progenitor had a pre-SN mass of ?3.5 M {sub ?} and that it could not be larger than ?8 M {sub ?}. We propose an interacting binary system as the SN progenitor and perform evolutionary calculations that are able to self-consistently explain the light curve shape, the absence of hydrogen, and the pre-SN photometry. We further discuss the range of allowed binary systems and predict that the remaining companion is a luminous O-type star of significantly lower flux in the optical than the pre-SN object. A future detection of such a star may be possible and would provide the first robust identification of a progenitor system for a Type Ib SN.

  17. Neutrino-driven explosions of ultra-stripped type Ic supernovae generating binary neutron stars

    E-Print Network [OSTI]

    Suwa, Yudai; Shibata, Masaru; Umeda, Hideyuki; Takahashi, Koh

    2015-01-01T23:59:59.000Z

    We study explosion characteristics of ultra-stripped supernovae (SNe), which are candidates of SNe generating binary neutron stars (NSs). As a first step, we perform stellar evolutionary simulations of bare carbon-oxygen cores of mass from 1.45 to 2.0 $M_\\odot$ until the iron cores become unstable and start collapsing. We then perform axisymmetric hydrodynamics simulations with spectral neutrino transport using these stellar evolution outcomes as initial conditions. All models exhibit successful explosions driven by neutrino heating. The diagnostic explosion energy, ejecta mass, Ni mass, and NS mass are typically $\\sim 10^{50}$ erg, $\\sim 0.1 M_\\odot$, $\\sim 0.01M_\\odot$, and $\\approx 1.3 M_\\odot$, which are compatible with observations of rapidly-evolving and luminous transient such as SN 2005ek. We also find that the ultra-stripped SN is a candidate for producing the secondary low-mass NS in the observed compact binary NSs like PSR J0737-3039.

  18. Tracing CNO exposed layers in the Algol-type binary system u Her

    E-Print Network [OSTI]

    Kolbas, V; Pavlovski, K; Southworth, J

    2014-01-01T23:59:59.000Z

    The chemical composition of stellar photospheres in mass-transferring binary systems is a precious diagnostic of the nucleosynthesis processes that occur deep within stars, and preserves information on the components history. The binary system u Her belongs to a group of hot Algols with both components being B-stars. We have isolated the individual spectra of the two components by the technique of spectral disentangling of a new series of 43 high-resolution echelle spectra. Augmenting these with an analysis of the Hipparcos photometry of the system yields revised stellar quantities for the components of u Her. For the primary component (the mass-gaining star) we find M_A = 7.88 +/- 0.26 M_sun, R_A = 4.93 +/- 0.15 R_sun and T_eff_A = 21600 +/- 220 K. For the secondary (the mass-losing star) we find M_B = 2.79 +/- 0.12 M_sun, R_B = 4.26 +/- 0.06 R_sun and T_eff_B = 12600 +/- 550 K. A non-LTE analysis of the primary star's atmosphere reveals deviations in the abundances of nitrogen and carbon from the standard c...

  19. Owners of nuclear power plants

    SciTech Connect (OSTI)

    Hudson, C.R.; White, V.S.

    1996-11-01T23:59:59.000Z

    Commercial nuclear power plants in this country can be owned by a number of separate entities, each with varying ownership proportions. Each of these owners may, in turn, have a parent/subsidiary relationship to other companies. In addition, the operator of the plant may be a different entity as well. This report provides a compilation on the owners/operators for all commercial power reactors in the United States. While the utility industry is currently experiencing changes in organizational structure which may affect nuclear plant ownership, the data in this report is current as of July 1996. The report is divided into sections representing different aspects of nuclear plant ownership.

  20. Is the central binary system of the planetary nebula Henize 2-428 a Type Ia supernova progenitor?

    E-Print Network [OSTI]

    Garcia-Berro, Enrique; Althaus, Leandro G

    2015-01-01T23:59:59.000Z

    We account for recent observations of the binary system at the center of the bipolar planetary nebula Henize 2-428 by the presence of one degenerate core with a low-mass main sequence companion, rather than by two degenerate objects. We argue that the variability of the He II 5412A spectral line can be accounted for by a time-varying broad absorption line from the central star on top of which there is a time-varying narrow emission line from the compact nebula. The two (almost) symmetric broad minima in the light curve are attributed to tidal distortion caused by a companion. We find problems in the recently proposed and competing explanation of two equal-mass degenerate objects that supposedly will eventually merge, possibly leading to a SN Ia. We conclude that Henize 2-428 cannot be claimed yet to support the double-degenerate scenario for Type Ia supernovae.

  1. SS 433: a WR X-ray binary or a WR-type phenomenon ?

    E-Print Network [OSTI]

    Yael Fuchs; L. Koch Miramond; P. Abraham

    2004-10-20T23:59:59.000Z

    We present mid-infrared spectra of the microquasar SS 433 obtained with the Infrared Space Observatory (spectroscopic mode of ISOPHOT) and compare them to the spectra of four Wolf-Rayet stars. The mid-infrared spectrum of SS 433 shows mainly HI and HeI emission lines and is very similar to the spectrum of WR 147, a WN8(h)+B0.5V binary with a colliding wind. The 2-12 micron continuum emission corresponds to optically thin and partially optically thick free-free emission from which we calculate a mass loss rate of 1.4-2.2x10^{-4} M_sun/yr if the wind is homogeneous and a third of these values if it is clumped, which is consistent with a strong WN stellar wind. We propose that this strong wind outflows from a geometrically thick envelope of material surrounding the compact object like a stellar atmosphere, imitating the Wolf-Rayet phenomenon.

  2. Gas pile-up, gap overflow, and Type 1.5 migration in circumbinary disks: application to supermassive black hole binaries

    E-Print Network [OSTI]

    Bence Kocsis; Zoltan Haiman; Abraham Loeb

    2012-09-13T23:59:59.000Z

    We study the interaction of a supermassive black hole (SMBH) binary and a standard radiatively efficient thin accretion disk. We examine steady-state configurations of the disk and migrating SMBH system, self-consistently accounting for tidal and viscous torques and heating, radiative diffusion limited cooling, gas and radiation pressure, and the decay of the binary's orbit. We obtain a "phase diagram" of the system as a function of binary parameters, showing regimes in which both the disk structure and migration have a different character. Although massive binaries can create a central gap in the disk at large radii, the tidal barrier of the secondary causes a significant pile-up of gas outside of its orbit, which can lead to the closing of the gap. We find that this spillover occurs at an orbital separation as large as ~200 M_7^{-1/2} gravitational radii, where M = 10^7 M_7 Msun is the total binary mass. If the secondary is less massive than ~10^6 Msun, then the gap is closed before gravitational waves (GWs) start dominating the orbital decay. In this regime, the disk is still strongly perturbed, but the piled-up gas continuously overflows as in a porous dam, and crosses inside the secondary's orbit. The corresponding migration rate, which we label Type 1.5, is slower than the usual limiting cases known as Type I and II migration. Compared to an unperturbed disk, the steady-state disk in the overflowing regime is up to several hundred times brighter in the optical bands. Surveys such as PanSTARRS or LSST may discover the periodic variability of this population of binaries. Our results imply that the circumbinary disks around SMBHs can extend to small radii during the last stages of their merger, when they are detectable by LISA, and may produce coincident electromagnetic (EM) emission similar to active galactic nuclei (AGN).

  3. An Internet survey of private pond owners and managers in Texas

    E-Print Network [OSTI]

    Schonrock, April Elizabeth

    2005-11-01T23:59:59.000Z

    pond owners got the information they used to deal with pond management problems. A secondary emphasis of the project was to examine the potential presented by the Internet for use in this type of information gathering and distribution for Texas...

  4. Nebular phase observations of the type-Ib supernova iPTF13bvn favour a binary progenitor

    E-Print Network [OSTI]

    Kuncarayakti, H; Bersten, M C; Folatelli, G; Morrell, N; Hsiao, E Y; Gonz醠ez-Gait醤, S; Anderson, J P; Hamuy, M; de Jaeger, T; Guti閞rez, C P; Kawabata, K S

    2015-01-01T23:59:59.000Z

    Aims. We present and analyse late-time observations of the type-Ib supernova with possible pre-supernova progenitor detection, iPTF13bvn, taken at $\\sim$300 days after the explosion, and discuss these in the context of constraints on the supernova's progenitor. Previous studies have proposed two possible natures for the progenitor of the supernova, i.e. a massive Wolf-Rayet star or a lower-mass star in close binary system. Methods. Our observations show that the supernova has entered the nebular phase, with the spectrum dominated by Mg~I]$\\lambda\\lambda$4571, [O~I]$\\lambda\\lambda$6300, 6364, and [Ca~II]$\\lambda\\lambda$7291, 7324 emission lines. We measured the emission line fluxes to estimate the core oxygen mass and compare the [O~I]/[Ca~II] line ratio with other supernovae. Results. The core oxygen mass of the supernova progenitor was estimated to be $\\lesssim$0.7 M$_\\odot$, which implies initial progenitor mass not exceeding $\\sim$15 -- 17 M$_\\odot$. Since the derived mass is too small for a single star to...

  5. A super-Eddington wind scenario for the progenitors of type Ia supernovae: binary population synthesis calculations

    E-Print Network [OSTI]

    Wang, Bo; Liu, Dongdong; Liu, Zhengwei; Wu, Chengyuan; Zhang, Jujia; Han, Zhanwen

    2015-01-01T23:59:59.000Z

    The super-Eddington wind scenario has been proposed as an alternative way for producing type Ia supernovae (SNe Ia). The super-Eddington wind can naturally prevent the carbon--oxygen white dwarfs (CO WDs) with high mass-accretion rates from becoming red-giant-like stars. Furthermore, it works in low-metallicity environments, which may explain SNe Ia observed at high redshifts. In this article, we systematically investigated the most prominent single-degenerate WD+MS channel based on the super-Eddington wind scenario. We combined the Eggleton stellar evolution code with a rapid binary population synthesis (BPS) approach to predict SN Ia birthrates for the WD+MS channel by adopting the super-Eddington wind scenario and detailed mass-accumulation efficiencies of H-shell flashes on the WDs. Our BPS calculations found that the estimated SN Ia birthrates for the WD+MS channel are ~0.009-0.315*10^{-3}{yr}^{-1} if we adopt the Eddington accretion rate as the critical accretion rate, which are much lower than that of ...

  6. Corporate Law's Current-Owner Bias

    E-Print Network [OSTI]

    Fried, Jesse M.

    2005-01-01T23:59:59.000Z

    Owner Bias in Corporate Governance Jesse Fried * Boalt Hallmy conclusion that corporate governance arrangements choseninterventions in corporate governance through the securities

  7. Corporate Law's Current-Owner Bias

    E-Print Network [OSTI]

    Fried, Jesse M.

    2006-01-01T23:59:59.000Z

    Owner Bias in Corporate Governance Jesse Fried * Boalt Hallmy conclusion that corporate governance arrangements choseninterventions in corporate governance through the securities

  8. Statistical Time-Resolved Spectroscopy: A higher fraction of short-period binaries for metal-rich F-type dwarfs in SDSS

    E-Print Network [OSTI]

    Hettinger, T; Strader, J; Bickerton, S J; Beers, T C

    2015-01-01T23:59:59.000Z

    Stellar multiplicity lies at the heart of many problems in modern astrophysics, including the physics of star formation, the observational properties of unresolved stellar populations, and the rates of interacting binaries such as cataclysmic variables, X-ray binaries, and Type Ia supernovae. However, little is known about the stellar multiplicity of field stars in the Milky Way, in particular about the differences in the multiplicity characteristics between metal-rich disk stars and metal-poor halo stars. In this study we perform a statistical analysis of ~15,000 F-type dwarf stars in the Milky Way through time-resolved spectroscopy with the sub-exposures archived in the Sloan Digital Sky Survey. We obtain absolute radial velocity measurements through template cross-correlation of individual sub-exposures with temporal baselines varying from minutes to years. These sparsely sampled radial velocity curves are analyzed using Markov chain Monte Carlo techniques to constrain the very short-period binary fraction...

  9. Tour of Entergy's Nuclear Power Plant in River Bend Owner: Entergy Gulf States Inc.

    E-Print Network [OSTI]

    Ervin, Elizabeth K.

    Tour of Entergy's Nuclear Power Plant in River Bend Owner: Entergy Gulf States Inc. Reactor Type a nuclear power plant. Plant was Entergy, a Boiling Water Reactor (BWR) type. Built in the 80's, it has of the veteran plant workers. The presentation gave the nuclear plant engineering basics and built

  10. TYPE-I X-RAY BURSTS REVEAL A FAST CO-EVOLVING BEHAVIOR OF THE CORONA IN AN X-RAY BINARY

    SciTech Connect (OSTI)

    Chen, Yu-Peng; Zhang, Shu; Zhang, Shuang-Nan; Li, Jian; Wang, Jian-Min, E-mail: chenyp@ihep.ac.cn, E-mail: szhang@ihep.ac.cn, E-mail: zhangsn@ihep.ac.cn [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China)

    2012-06-20T23:59:59.000Z

    The coronae in X-ray binaries (XRBs) still remain poorly understood, although they have been believed for a long time to play a key role in modeling the characteristic outbursts of XRBs. Type-I X-ray bursts, the thermonuclear flashes happening on the surface of a neutron star (NS), can be used as a probe to the innermost region of an NS XRB, where the corona is believed to be located very close to the NS. We report the discovery of a tiny life cycle of the corona that is promptly co-evolved with the type-I bursts superimposed on the outburst of the NS XRB IGR J17473-2721. This finding may serve as the first evidence of directly seeing the rapid disappearance and formation of a corona in an XRB with a cooling/heating timescale of less than a second, which can strongly constrain the accretion models in XRBs at work.

  11. Tips For Residential Heating Oil Tank Owners

    E-Print Network [OSTI]

    Maroncelli, Mark

    路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 路 Tips For Residential Heating Oil Tank Owners Source: DEP Fact Sheet Residential heating oil tanks are used to store fuel for furnaces or boilers to heat

  12. Governmental-Owner Power Imbalance and Privatization

    E-Print Network [OSTI]

    Xu, Kehan

    2011-10-21T23:59:59.000Z

    fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Laszlo Tihanyi Committee Members, Michael Hitt Lorraine Eden Allan (Haipeng) Chen Head of Department, Murray Barrick August 2010... Major Subject: Management iii ABSTRACT Governmental-Owner Power Imbalance and Privatization. (August 2010) Kehan Xu, B.S., China Criminal Police College; M.B.A., University of Miami Chair of Advisory Committee: Dr. Laszlo Tihanyi...

  13. Property:Owner | 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 form History Facebook icon Twitter iconNumOfPlants Jump to:Tool/KeywordOwner

  14. DOE/NNSA Facility Management Contracts Facility Owner Contractor

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

    NNSA Facility Management Contracts Facility Owner Contractor Award Date End Date OptionsAward Term Ultimate Potential Expiration Date Contract FY Competed Parent Companies LLC...

  15. Rights and Duties of Mines and Mine Owners, General (Missouri)

    Broader source: Energy.gov [DOE]

    This legislation addresses general operational guidelines for mine owners regarding public notices, fees, land and mineral ownership, requirements for mining in certain municipalities, and mining...

  16. Facility Name Facility Name Facility FacilityType Owner Developer...

    Open Energy Info (EERE)

    Juhl Wind Meeker County MN MW Alstom In Service Aegir II Aegir II Aegir II Offshore Wind Lake Michigan MI MW Proposed Aero Turbine Aero Turbine Aero Turbine Commercial Scale...

  17. Guide to Combined Heat and Power Systems for Boiler Owners and...

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

    Combined Heat and Power Systems for Boiler Owners and Operators, July 2004 Guide to Combined Heat and Power Systems for Boiler Owners and Operators, July 2004 Many owners and...

  18. Microlensing Detections of Planets in Binary Stellar Systems

    E-Print Network [OSTI]

    Dong-Wook Lee; Chung-Uk Lee; Byeong-Gon Park; Sun-Ju Chung; Young-Soo Kim; Ho-Il Kim; Cheongho Han

    2007-09-13T23:59:59.000Z

    We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems where the planet orbits one of the binary component and the other binary star is located at a large distance, both planet and secondary companion produce perturbations at a common region around the planet-hosting binary star and thus the signatures of both planet and binary companion can be detected in the light curves of high-magnification lensing events. We find that identifying planets in binary systems is optimized when the secondary is located in a certain range which depends on the type of the planet. The proposed method can detect planets with masses down to one tenth of the Jupiter mass in binaries with separations planet mass and binary separation are not covered by other methods and thus microlensing would be able to make the planetary binary sample richer.

  19. Eclipsing Binaries in the Young LMC Cluster NGC 1850

    E-Print Network [OSTI]

    Stuart F. Taylor

    2004-10-21T23:59:59.000Z

    I present light curves for two detached eclipsing binary stars in the region of the LMC cluster NGC 1850, which is possibly a young globular cluster still in formation. One, a likely spectral type O star, is a newly detected eclipsing binary in the region of the very young subcluster NGC 1850A. This binary is among a small number of highly massive O-type stars in binary systems found in LMC clusters. These two eclipsing binaries are the first discovered in the well studied NGC 1850, and the O-type star is the first eclisping binary found in NGC 1850A. Light curves for two NGC 1850 region Cepheid variables are also shown. Discovering two eclipsing binaries in the young globlular-like cluster NGC 1850 is discussed in terms of the importance of the binary fraction to globular cluster evolution.

  20. MAINE MULTIFAMILY BUILDING OWNERS TRUST IN EFFICIENCY | Department...

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

    MAINE MULTIFAMILY BUILDING OWNERS TRUST IN EFFICIENCY Nearly 70% of households in Maine rely on fuel oil as their primary energy source for home heating, more than any other state....

  1. Owner/contractor work structure process with integrated alignment framework

    E-Print Network [OSTI]

    Sullivan, George Ray

    1996-01-01T23:59:59.000Z

    capital program expenditures , and to improve operational efficiency. For their capital projects, owners want the highest quality project, as fast as possible, at the lowest possible cost, with no harm to workers or the environment. To accomplish this...

  2. The Impact of Energy Information Upon Small Business Owners

    E-Print Network [OSTI]

    Franklin, Casey Gail

    2014-05-31T23:59:59.000Z

    . Findings indicated that although each participant expressed an interest in conserving energy, none were regularly engaging with their electricity consumption information through the online monitor. Business owners did not find the monitor useful because...

  3. Eclipsing Binaries in the OGLE Variable Star Catalogs.V. Long-Period Beta Lyrae-type Systems in the Small Magellanic Cloud and the PLC-beta Relation

    E-Print Network [OSTI]

    Slavek M. Rucinski; Carla Maceroni

    2000-06-16T23:59:59.000Z

    Thirty eight long-period (P>10 days), apparently contact binary stars discovered by the OGLE-II project in the SMC appear to be Beta Lyrae-type systems with ellipsoidal variations of the cool components dominating over eclipse effects in the systemic light variations and in the total luminosity. A new period-luminosity- color (PLC) relation has been established for these systems; we call it the PLC-beta relation, to distinguish it from the Cepheid relation. Two versions of the PLC-beta relation - based on the (B-V)0 or (V-I)0 color indices - have been calibrated for 33 systems with (V-I)0>0.25 spanning the orbital period range of 11 to 181 days. The relations can provide maximum-light, absolute-magnitude estimates accurate to epsilon-M_V~0.35 mag. within the approximate range -3PLC-beta relation can offer an auxiliary and entirely independent method of distance determination to nearby stellar systems rich in massive stars. The sample of the long-period Beta Lyrae systems in the SMC analyzed in this paper is currently the best defined and uniform known sequence of such binaries.

  4. Design Team:Owners Team: Solaris Group, LLC

    E-Print Network [OSTI]

    Solaris Port of Benton NORTH #12;Climate and Design Maximize East/West Solar Orientation 路 Reduce ThermalDesign Team:Owners Team: Solaris Group, LLC a management company TRI-CITIES RESEARCH DISTRICT Prevailing Winds for Passive Site Cooling 路 Deter Winter Gusts 路 Protection via Walkway Screens and Canopies

  5. COMMUNITY RESILIENCE: WORKSHOPS ON PRIVATE SECTOR AND PROPERTY OWNER

    E-Print Network [OSTI]

    STATES DEPARTMENT OF ENERGY under Contract DE-AC05-76RL01830 #12;Acknowledgments The authors would like to acknowledge and thank the businesses, building owners, service providers, and representatives who participated .....................................................................................3 4.1 Workshop with Private Sector Businesses on August 12

  6. THE POST-MERGER MAGNETIZED EVOLUTION OF WHITE DWARF BINARIES: THE DOUBLE-DEGENERATE CHANNEL OF SUB-CHANDRASEKHAR TYPE Ia SUPERNOVAE AND THE FORMATION OF MAGNETIZED WHITE DWARFS

    SciTech Connect (OSTI)

    Ji Suoqing; Fisher, Robert T. [University of Massachusetts Dartmouth, Department of Physics, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Garcia-Berro, Enrique [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, E-08860 Castelldefels (Spain); Tzeferacos, Petros; Jordan, George; Lee, Dongwook [Center for Astrophysical Thermonuclear Flashes, The University of Chicago, Chicago, IL 60637 (United States); Loren-Aguilar, Pablo [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Cremer, Pascal [Bethe Center for Theoretical Physics, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany); Behrends, Jan [Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    2013-08-20T23:59:59.000Z

    Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths {approx}2 Multiplication-Sign 10{sup 8} G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.

  7. How life insurance can benefit the business owner

    SciTech Connect (OSTI)

    Byles, B.

    1993-02-01T23:59:59.000Z

    There are many situations when life insurance can fill the financial needs of business owners. Three of the most common needs are business continuation/value conservation (buy-sell agreement), asset conservation upon death or disability of a key employee (replace the value of a key employee upon death or disability), and the reward and retention of selected employees (bonus or deferred compensation). Let's take a closer look to see why life insurance makes sense in these three areas.

  8. Photon transport in binary photonic lattices

    E-Print Network [OSTI]

    B. M. Rodr韌uez-Lara; H. Moya-Cessa

    2013-01-08T23:59:59.000Z

    We present a review on the mathematical methods used to theoretically study classical propagation and quantum transport in arrays of coupled photonic waveguides. We focus on analysing two types of binary photonic lattices where self-energies or couplings are alternated. For didactic reasons, we split the analysis in classical propagation and quantum transport but all methods can be implemented, mutatis mutandis, in any given case. On the classical side, we use coupled mode theory and present an operator approach to Floquet-Bloch theory in order to study the propagation of a classical electromagnetic field in two particular infinite binary lattices. On the quantum side, we study the transport of photons in equivalent finite and infinite binary lattices by couple mode theory and linear algebra methods involving orthogonal polynomials. Curiously the dynamics of finite size binary lattices can be expressed as roots and functions of Fibonacci polynomials.

  9. Electromagnetic Signatures of Massive Black Hole Binaries

    E-Print Network [OSTI]

    Tamara Bogdanovic; Britton D. Smith; Michael Eracleous; Steinn Sigurdsson

    2006-09-28T23:59:59.000Z

    We model the electromagnetic emission signatures of massive black hole binaries (MBHBs) with an associated gas component. The method comprises numerical simulations of relativistic binaries and gas coupled with calculations of the physical properties of the emitting gas. We calculate the accretion powered UV/X-ray and Halpha light curves and the Halpha emission line profiles. The simulations have been carried out with a modified version of the parallel tree SPH code Gadget. The heating, cooling, and radiative processes for the solar metallicity gas have been calculated with the photoionization code Cloudy. We investigate gravitationally bound, sub-parsec binaries which have not yet entered the gravitational radiation phase. The results from the first set of calculations, carried out for a coplanar binary and gas disk, suggest that the outbursts in the X-ray light curve are pronounced during pericentric passages and can serve as a fingerprint for this type of binaries if periodic outbursts are a long lived signature of the binary. The Halpha emission-line profiles also offer strong indications of a binary presence and may be used as a criterion for selection of MBHB candidates for further monitoring from existing archival data. The orbital period and mass ratio of a binary could be determined from the Halpha light curves and profiles of carefully monitored candidates. Although systems with the orbital periods studied here are not within the frequency band of the Laser Interferometer Space Antenna (LISA), their discovery is important for understanding of the merger rates of MBHBs and the evolution of such binaries through the last parsec and towards the detectable gravitational wave window.

  10. Observational Techniques for Detecting Planets in Binary Systems

    E-Print Network [OSTI]

    Matthew W. Muterspaugh; Maciej Konacki; Benjamin F. Lane; Eric Pfahl

    2007-05-21T23:59:59.000Z

    Searches for planets in close binary systems explore the degree to which stellar multiplicity inhibits or promotes planet formation. There is a degeneracy between planet formation models when only systems with single stars are studied--several mechanisms appear to be able to produce such a final result. This degeneracy is lifted by searching for planets in binary systems; the resulting detections (or evidence of non-existence) of planets in binaries isolates which models may contribute to how planets form in nature. In this chapter, we consider observational efforts to detect planetary companions to binary stars in two types of hierarchical planet-binary configurations: first ``S-type'' planets which orbit just one of the stars, with the binary period being much longer than the planet's; second, ``P-type'' or circumbinary planets, where the planet simultaneously orbits both stars, and the planetary orbital period is much longer than that of the binary. The S-type planet finding techniques are different for binaries that can or cannot be spatially resolved. For wider systems, techniques reviewed include dualstar interferometric differential astrometry and precision radial velocities. Alternatively, unresolved binaries can be studied using modified dualstar "PHASES-style" differential astrometry or a modification of the radial velocity technique for composite spectra. Should a fortunately aligned--but still long period--binary be found, eclipse timing can also reveal the presence of S-type planets. Methods for detecting P-type planets include the composite-spectra variant of the radial velocity technique and eclipse timing.

  11. Building Energy Asset Score: Building Owners | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Future ofHydronicBuildingDepartment ofCodesBuilding Owners

  12. Guide to Combined Heat and Power Systems for Boiler Owners and...

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

    the Department of Energy to improve steam system performance. Guide to Combined Heat and Power Systems for Boiler Owners and Operators (July 2004) More Documents & Publications...

  13. Trigonometric Parallaxes for Two Late-Type Subdwarfs: LSR1425+71 (sdM8.0) and the Binary LSR1610-00 (sd?M6pec)

    E-Print Network [OSTI]

    C. C. Dahn; H. C. Harris; S. E. Levine; T. Tilleman; A. K. B. Monet; R. C. Stone; H. H. Guetter; B. Canzian; J. R. Pier; W. I. Hartkopf; J. Liebert; M. Cushing

    2008-06-13T23:59:59.000Z

    Trigonometric parallax astrometry and BVI photometry are presented for two late-type subdwarf candidates, LSR1425+71 (sdM8.0) and LSR1610-00 (sd?M6pec). For the former we measure an absolute parallax of 13.37+/-0.51 mas yielding Mv=15.25+/-0.09. The astrometry for LSR1610-00 shows that this object is an astrometric binary with a period of 1.66+/-0.01 yr. The photocentric orbit is derived from the data; it has a moderate eccentricity (e ~ 0.44+/-0.02) and a semi-major axis of 0.28+/-0.01 AU based on our measured absolute parallax of 31.02+/-0.26 mas. Our radial velocity measure of -108.1+/-1.6 km/s for LSR1610-00 at epoch 2006.179, when coupled with the observation of -95+/-1 km/s at epoch 2005.167 by Reiners & Basri, indicates a systemic radial velocity of -101+/-1 km/s for the LSR1610-00AB pair. The galactic velocity components for LSR1425+71 and LSR1610-00AB -- (U,V,W)=(84+/-6, -202+/-13, 66+/-14) km/s and (U,V,W)=(36+/-2, -232+/-2, -61+/-2) km/s, respectively. For both stars, the velocities are characteristic of halo population kinematics. However, modeling shows that both stars have orbits around the galaxy with high eccentricity that pass remarkably close to the galactic center. LSR1425+71 has a luminosity and colors consistent with its metal-poor subdwarf spectral classification, while LSR1610-00 has a luminosity and most colors indicative of being only mildly metal-poor, plus a uniquely red B-V color. The companion to LSR1610-00 must be a low-mass, substellar brown dwarf. We speculate on the paradoxical nature of LSR1610-00 and possible sources of its peculiarities.

  14. The contact binary GSC 04778-00152 with a visual companion

    E-Print Network [OSTI]

    T. Tuvikene; T. Eenm鋏; C. Sterken; E. Brogt

    2008-09-11T23:59:59.000Z

    Photometric and spectroscopic observations of the unstudied 12th-magnitude eclipsing binary GSC 04778-00152 are presented. We report the discovery of a visual companion about 1 mag fainter and 2 arcsec away from the binary. By subtracting the light contribution of the visual companion, we obtain the UBVRI light curves of the binary system alone. The shape of the light curve indicates that GSC 04778-00152 is an A-type W UMa contact binary. From light-curve modeling, we derive parameters of the binary system.

  15. MEMORANDUM OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling CorpNewCF INDUSTRIES,L? .-IGY DATE---I TO:

  16. OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN .METALS~ c3 Alexander9412,l . . ;

  17. OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN .METALS~ c3 Alexander9412,l . .

  18. OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN .METALS~ c3 Alexander9412,l .

  19. OWNER(S) Past:

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN .METALS~ c3 Alexander9412,l

  20. SUBJECT: OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3u ;;;:: A' 3

  1. DOE NSTB Researchers Demonstrate R&D Successes to Asset Owners at EnergySec Conference

    Broader source: Energy.gov [DOE]

    More than 150 energy sector leaders梚ncluding nearly 100 asset owners and operators梘athered at the 2009 EnergySec Annual Summit in Seattle, WA, on Sept. 23-24, where researchers from the...

  2. The Formation of Population III Binaries

    E-Print Network [OSTI]

    Kazuya Saigo; Tomoaki Matsumoto; Masayuki Umemura

    2004-10-29T23:59:59.000Z

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

  3. On the Neutron Star-Black Hole Binaries Produced by Binary-driven Hypernovae

    E-Print Network [OSTI]

    Fryer, C L; Rueda, J A; Ruffini, R

    2015-01-01T23:59:59.000Z

    Binary-driven hypernovae (BdHNe) following the induced gravitational collapse (IGC) paradigm have been introduced to explain the concomitance of energetic long gamma-ray bursts (GRBs) with type Ic supernovae. The progenitor system is a tight binary system composed of a carbon-oxygen (CO) core and a neutron star (NS) companion. The supernova ejecta of the exploding CO core triggers a hypercritical accretion process onto the NS, which in a few seconds reach the NS critical mass, and gravitationally collapses to a black hole (BH) emitting a GRB. These tight binary systems evolve through the supernova explosion very differently than compact binary progenitors studied in population synthesis calculations. First, the hypercritical accretion onto the NS companion alters both the mass and momentum of the binary. Second, because the explosion timescale is on par with the orbital period, the mass ejection can not be assumed to be instantaneous. Finally, the bow shock created as the accreting NS plows through the supern...

  4. Energy Efficiency: Helping Home Owners and Businesses Understand...

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

    placed throughout the building to serve as a representative sample across a wide range of device types. In the office building, the most common devices were computers, computer...

  5. Accretion in Compact Binaries

    E-Print Network [OSTI]

    Andrew R. King

    2003-03-26T23:59:59.000Z

    Compact binaries have long been a paradigm for accretion theory. Much of our present view of how accretion occurs comes directly from the comparison of theory with observations of these sources. Since theory differs little for other objects such as active galaxies, increasing efforts have recently gone into searching for correspondences in observed behaviour. This chapter aims at giving a concise summary of the field, with particular emphasis on new developments since the previous edition of this book. These developments have been significant. Much of the earlier literature implicitly assumed that accreting binaries were fairly steady sources accreting most of the mass entering their vicinity, often with main-sequence companions, and radiating the resulting accretion luminosity in rough isotropy. We shall see that in reality these assumptions fail for the majority of systems. Most are transient; mass ejection in winds and jets is extremely common; a large (sometimes dominant) fraction of even short-period systems have evolved companions whose structure deviates significantly from the zero-age main sequence; and the radiation pattern of many objects is significantly anisotropic. It is now possible to give a complete characterization of the observed incidence of transient and persistent sources in terms of the disc instability model and formation constraints. X-ray populations in external galaxies, particularly the ultraluminous sources, are revealing important new insights into accretion processes and compact binary evolution.

  6. Isobaric vapor-liquid equilibria for methanol + ethanol + water and the three constituent binary systems

    SciTech Connect (OSTI)

    Kurihara, Kiyofumi; Nakamichi, Mikiyoshi; Kojima, Kazuo (Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry)

    1993-07-01T23:59:59.000Z

    Vapor-liquid equilibrium data for methanol + ethanol + water and its three constituent binary systems methanol + ethanol, ethanol + water, and methanol + water were measured at 101.3 kPa using a liquid-vapor ebullition-type equilibrium still. The experimental binary data were correlated by the NRTL equation. The ternary system methanol + ethanol + water was predicted by means of the binary NRTL parameters with good accuracy.

  7. Astrophysics of white dwarf binaries

    E-Print Network [OSTI]

    G. Nelemans

    2007-03-13T23:59:59.000Z

    White dwarf binaries are the most common compact binaries in the Universe and are especially important for low-frequency gravitational wave detectors such as LISA. There are a number of open questions about binary evolution and the Galactic population of white dwarf binaries that can be solved using gravitational wave data and at the same time, our ever improving knowledge about these binaries will help to predict the signals that can be expected for LISA. In addition a number of white dwarf binaries will serve as verification sources for the instrument. I will discuss these issues and report recent, surprising, developments in this field. Finally I report calculations about the feasibility of complementary electro-magnetic observations which unfortunately cannot reproduce the optimistic results of Cooray et al. (2004).

  8. BINARY CEPHEIDS: SEPARATIONS AND MASS RATIOS IN 5 M {sub ?} BINARIES

    SciTech Connect (OSTI)

    Evans, Nancy Remage; Karovska, Margarita; Tingle, Evan [Smithsonian Astrophysical Observatory, MS 4, 60 Garden Street, Cambridge, MA 02138 (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Schaefer, Gail H. [The CHARA Array, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965 (United States); Mason, Brian D., E-mail: nevans@cfa.harvard.edu, E-mail: heb11@psu.edu, E-mail: schaefer@chara-array.org [US Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420 (United States)

    2013-10-01T23:59:59.000Z

    Deriving the distribution of binary parameters for a particular class of stars over the full range of orbital separations usually requires the combination of results from many different observing techniques (radial velocities, interferometry, astrometry, photometry, direct imaging), each with selection biases. However, Cepheids梒ool, evolved stars of ?5 M {sub ?}梐re a special case because ultraviolet (UV) spectra will immediately reveal any companion star hotter than early type A, regardless of the orbital separation. We have used International Ultraviolet Explorer UV spectra of a complete sample of all 76 Cepheids brighter than V = 8 to create a list of all 18 Cepheids with companions more massive than 2.0 M {sub ?}. Orbital periods of many of these binaries are available from radial-velocity studies, or can be estimated for longer-period systems from detected velocity variability. In an imaging survey with the Hubble Space Telescope Wide Field Camera 3, we resolved three of the companions (those of ? Aql, S Nor, and V659 Cen), allowing us to make estimates of the periods out to the long-period end of the distribution. Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations, orbital periods, and mass ratios. The distribution of orbital periods shows that the 5 M {sub ?} binaries have systematically shorter periods than do 1 M {sub ?} stars. Our data also suggest that the distribution of mass ratios depends on both binary separation and system multiplicity. The distribution of mass ratios as a function of orbital separation, however, does not depend on whether a system is a binary or a triple.

  9. Dynamic Tides in Close Binaries

    E-Print Network [OSTI]

    B. Willems

    2005-11-10T23:59:59.000Z

    The basic theory of dynamic tides in close binaries is reviewed. Particular attention is paid to resonances between dynamic tides and free oscillation modes and to the role of the apsidal-motion rate in probing the internal structure of binary components. The discussed effects are generally applicable to stars across the entire Hertzsprung-Russell diagram, including the binary OB-stars discussed at this meeting.

  10. Chaos in Binary Category Computation

    E-Print Network [OSTI]

    Carlos Pedro Gon鏰lves

    2010-11-21T23:59:59.000Z

    Category computation theory deals with a web-based systemic processing that underlies the morphic webs, which constitute the basis of categorial logical calculus. It is proven that, for these structures, algorithmically incompressible binary patterns can be morphically compressed, with respect to the local connectivities, in a binary morphic program. From the local connectivites, there emerges a global morphic connection that can be characterized by a low length binary string, leading to the identification of chaotic categorial dynamics, underlying the algorithmically random pattern. The work focuses on infinite binary chains of C2, which is a category that implements an X-OR-based categorial logical calculus.

  11. IntrAst2 (Petrovay) Binaries BINARY STARS

    E-Print Network [OSTI]

    Petrovay, Krist骹

    ;IntrAst2 (Petrovay) Binaries The Doppler effect and stellar radial velocities Moving wave source / = /c : recession velocity of source; c: wave propagation speed (for c) Radial velocities of nearby) Spectroscopic binaries Periodic wavelength shifts in spectral lines due to orbital motion (Doppler shifts). #12

  12. REVIEW OF TRANSAMERICA DELAVAL INC. DIESEL GENERATOR OWNERS' GROUP ENGINE REQUALIFICATION PROGRAM

    SciTech Connect (OSTI)

    Berlinger, C. H.

    1985-12-01T23:59:59.000Z

    In December 1983, 13 nuclear utilities that own TDI diesel generators formally established an Owners Group to address concerns regarding the reliability and operability of these engines. The Owners' Group program for engine requalification consisted of four major elements: 1) resolution of known problems with potentially generic implications, 2) a design review and quality revalidation (DR/QR) effort aimed at identifying and correcting potential problems with the important engine components, 3) expanded engine testing and inspection, and 4) enhanced engine maintenance and surveillance (M/S) to maintain the qualification of the diesel engines for the lifetime of the nuclear plants that they service. In providing technical support to NRC, the PNL project staff, assisted by a number of diesel engine consultants, focused on the four major elements of the Owners' Group engine requalification program, addressing both generic and plant-specific areas.

  13. Beowawe Binary Bottoming Cycle

    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: The FutureCommentsEnergy Christopher| Department ofBeowawe Binary Bottoming

  14. Binary Frequencies in Globular Clusters

    E-Print Network [OSTI]

    Ji, Jun

    2015-01-01T23:59:59.000Z

    Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the ACS on the Hubble Space Telescope. When compared to the values of prior efforts (Sollima et al. 2007; Milone et al. 2012), we find significant discrepancies, despite each group correcting for contamination effects and having performed the appropriate reliability tests. The most reliable binary fractions are obtained when restricting the binary fraction to q > 0.5. Our analysis indicates that the range of the binary fractions is nearly an order of magnitude for the lowest dynamical ages, suggesting that there is a broad distribution in the binary fraction at globular cluster formation. Dynamical effects also appears to decrease the core binary fractions by a factor of two over a Hubble time, but this is a weak relationship. We confirm a correlation from previous work that the binary fraction within the core radius d...

  15. The Formation of Population III Binaries

    E-Print Network [OSTI]

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

    2004-01-01T23:59:59.000Z

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

  16. Gamma-ray emission from binaries in context

    E-Print Network [OSTI]

    Dubus, Guillaume

    2015-01-01T23:59:59.000Z

    More than a dozen binary systems are now established as sources of variable, high energy (HE, 0.1-100 GeV) gamma rays. Five are also established sources of very high energy (VHE, >100 GeV) gamma rays. The mechanisms behind gamma-ray emission in binaries are very diverse. My current understanding is that they divide up into four types of systems: gamma-ray binaries, powered by pulsar rotation; microquasars, powered by accretion onto a black hole or neutron star; novae, powered by thermonuclear runaway on a white dwarf; colliding wind binaries, powered by stellar winds from massive stars. Some of these types had long been suspected to emit gamma rays (microquasars), others have taken the community by surprise (novae). My purpose here is to provide a brief review of the current status of gamma-ray emission from binaries, in the context of related objects where similar mechanisms are at work (pulsar wind nebulae, active galactic nuclei, supernova remnants).

  17. A unique program for horse business owners Tuesdays, February 5 -March 19 (seven weeks)

    E-Print Network [OSTI]

    Goodman, Robert M.

    A unique program for horse business owners Tuesdays, February 5 - March 19 (seven weeks) 6:00pm 颅 9 budgeting plan by the end of the seven-week course. The course is offered by Dr. Carey Williams, Equine@njaes.rutgers.edu, 848-932-3229 $70.00 per person Dinner and Companion workbook included. Equine Business Planning Course

  18. WORKING PAPER N 2013 11 The Grey Paradox: How Oil Owners Can Benefit

    E-Print Network [OSTI]

    Paris-Sud XI, Universit茅 de

    , Fossil Fuels, GlobalWarming, Non-renewable Resources, OPEC PARIS-JOURDAN SCIENCES ECONOMIQUES 48, BD, Fossil Fuels, Global Warming, Non-renewable Resources, OPEC. JEL Classication: H21, H23, Q31, Q38, Q41, Q of fossil-fuel owners de- pends on the characteristics of their fossil fuels (recoverable reserves

  19. Adsorption and desorption of binary mixtures of volatile organic contaminants on soil

    E-Print Network [OSTI]

    Guo, Yang

    1995-01-01T23:59:59.000Z

    , the potential theory and the ideal adsorbed solution theory for mixture adsorption were also evaluated for prediction of the experimental results for binary adsorption. All models failed for prediction of the BET type III isotherms when methanol was present...

  20. Ba and Ni speciation in a nodule of binary Mn oxide phase composition from Lake Baikal

    E-Print Network [OSTI]

    , and absorption spectroscopy. Fe is speciated as goethite, and Mn as romanechite (psilomelane) and 10 A is separated from the other type by goethite. The binary Mn oxide banding pattern is interpreted by a two

  1. g:\\fpdc\\contracts unit\\consultant selection and agreement forms\\consultant agreements\\owner consultant agreement final pdc.doc Page 1 of 24

    E-Print Network [OSTI]

    Dyer, Bill

    \\owner consultant agreement final pdc.doc Page 1 of 24 MONTANA STATE UNIVERSITY PLANNING, DESIGN & CONSTRUCTION 6TH forms\\consultant agreements\\owner consultant agreement final pdc.doc Page 2 of 24 TABLE OF CONTENTS PART\\consultant selection and agreement forms\\consultant agreements\\owner consultant agreement final pdc.doc Page 3 of 24 1

  2. Spectroscopic Binaries in Globular Clusters. I. A Search for Ultra-Hard Binaries on the Main Sequence in M4

    E-Print Network [OSTI]

    Patrick Cote; Phil Fischer

    1996-05-02T23:59:59.000Z

    A search for spectroscopic binaries on the main sequence of the nearby globular cluster M4 has been undertaken with Argus, the multi-object spectrograph on the CTIO 4.0m telescope. A pair of radial velocities (median precision $\\simeq$ 2 km/s) separated by 11 months have been obtained for 33 turnoff dwarfs in the magnitude range 16.9 $\\le$ V $\\le$ 17.4. Monte-Carlo simulations have been used to derive a binary fraction, X, for systems with periods in the range 2 days $\\lae {\\rm P} \\lae$ 3 years and mass ratios between 0.2 and 1.0. This short-period cutoff is more than an order of magnitude smaller than those of existing radial velocity surveys and is comparable to the shortest periods possible for main-sequence turnoff stars. Our survey therefore provides a first glimpse into the abundance of ``ultra-hard" spectroscopic binaries in globular clusters. Although no star shows a velocity variation larger than 14 km/s, two objects are observed to have chi-square probabilities below 0.1\\%. No such stars are expected in a sample of 33. We find a best-fit binary fraction of X $\\simeq$ 0.15, a value which is consistent with recent estimates based on deep HST color-magnitude diagrams, as well as with the binary fraction of X $\\simeq$ 0.1 for nearby solar-type stars having similar periods and mass ratios. Our derived binary fraction suggests that exchange interactions with pre-existing binaries are a plausible means of explaining the origin of the hierarchical triple system containing the pulsar PSR 1620-26.

  3. Federal offshore oil and gas lease bonus bid rejections: viewpoints of bidders and owners

    SciTech Connect (OSTI)

    Lohrenz, J.; Dougherty, E.L.

    1983-03-01T23:59:59.000Z

    The Federal Government currently estimates values of leases offered in offshore oil and gas sales. After sales, the estimates are compared with highest bonus bids to decide whether to issue a lease or not. Over the past decade the Government has opted via this process not to issue leases on approximately one out of seven leases receiving bonus bids. The Government avows this assures fair market value is received. The authors believe this avowal is hogwash. The authors support this belief with logical argument, quantitative analysis, and statistical study. They conclude that by following the current policy, the Federal Government acting as agent for all of us, the collected people and owners of the lands in question, is acting to the detriment of the account they should serve. Alternative policies are proposed which both increase the efficiency of bringing offshore oil and gas resources to use and decrease the expense the Government burdens the owners with.

  4. The effect of landownership change among small woodland owners on timber availability in East Texas

    E-Print Network [OSTI]

    Gehlhausen, Randy Joe

    1976-01-01T23:59:59.000Z

    Forest Ownership Past Management Practices Past Harvesting H1. story Futu e Nanagement Intentions Future Harvesting Plans Statistical Analysis of Landowner Ccaracteristics Restrictions 18 20 22 22 25 25 25 29 29 29 33 33 33 36 39 48... of respondents according to future plans to consult foresters 51 24. Distribution of respondents according to future plans to participate in assistance programs 53 25, Willingness to sell timber among owners of less than 100 acres of 56 forest 26. Summary...

  5. Design-Build and CM at Risk- comparative analysis for owner decision making based on case studies and project surveys

    E-Print Network [OSTI]

    Park, Soon Rock

    2012-07-16T23:59:59.000Z

    Currently, many researchers and stakeholders believe that effective delivery systems for construction projects are key to improving project quality and value in the construction industry. Therefore, it is important that owners use the best project...

  6. Community Resilience: Workshops on Private Sector and Property Owner Requirements for Recovery and Restoration from a Diasaster

    SciTech Connect (OSTI)

    Judd, Kathleen S.; Stein, Steven L.; Lesperance, Ann M.

    2008-12-22T23:59:59.000Z

    This report summarizes the results of a proejct sponsored by DTRA to 1) Assess the readiness of private-sector businesses, building owners, and service providers to restore property and recover operations in the aftermath of a wide-area dispersal of anthrax; and 2) Understand what private property owners and businesses "want and need" from federal, state, and local government to support recovery and restoration from such an incident.

  7. Spectral analysis of X-ray binaries

    E-Print Network [OSTI]

    Fridriksson, Joel Karl

    2011-01-01T23:59:59.000Z

    In this thesis, I present work from three separate research projects associated with observations of X-ray binaries. Two of those revolve around spectral characteristics of neutron star low-mass X-ray binaries (NS-LMXBs), ...

  8. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    SciTech Connect (OSTI)

    Weinberg, Nevin N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Arras, Phil [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Quataert, Eliot; Burkart, Josh, E-mail: nevin@mit.edu [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States)

    2012-06-01T23:59:59.000Z

    We study the excitation and damping of tides in close binary systems, accounting for the leading-order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct physical effects: three-mode nonlinear interactions, i.e., the redistribution of energy among stellar modes of oscillation, and nonlinear excitation of stellar normal modes by the time-varying gravitational potential of the companion. This paper, the first in a series, presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism we present is applicable to binaries containing stars, planets, and/or compact objects, we focus on non-rotating solar-type stars with stellar or planetary companions. Our primary results include the following: (1) The linear tidal solution almost universally used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited internal gravity waves in solar-type stars are nonlinearly unstable to parametric resonance for companion masses M' {approx}> 10-100 M{sub Circled-Plus} at orbital periods P Almost-Equal-To 1-10 days. The nearly static 'equilibrium' tidal distortion is, however, stable to parametric resonance except for solar binaries with P {approx}< 2-5 days. (2) For companion masses larger than a few Jupiter masses, the dynamical tide causes short length scale waves to grow so rapidly that they must be treated as traveling waves, rather than standing waves. (3) We show that the global three-wave treatment of parametric instability typically used in the astrophysics literature does not yield the fastest-growing daughter modes or instability threshold in many cases. We find a form of parametric instability in which a single parent wave excites a very large number of daughter waves (N Almost-Equal-To 10{sup 3}[P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of Almost-Equal-To N faster than the standard three-wave parametric instability. These are local instabilities viewed through the lens of global analysis; the coherent global growth rate follows local rates in the regions where the shear is strongest. In solar-type stars, the dynamical tide is unstable to this collective version of the parametric instability for even sub-Jupiter companion masses with P {approx}< a month. (4) Independent of the parametric instability, the dynamical and equilibrium tides excite a wide range of stellar p-modes and g-modes by nonlinear inhomogeneous forcing; this coupling appears particularly efficient at draining energy out of the dynamical tide and may be more important than either wave breaking or parametric resonance at determining the nonlinear dissipation of the dynamical tide.

  9. Trajectories of the images in binary microlensing

    E-Print Network [OSTI]

    V. Bozza

    2001-05-16T23:59:59.000Z

    We study in detail the trajectories followed by single images during binary microlensing events. Starting from perturbative resolutions of the lens equation, we explore the full parameter space by continuity arguments. We see that the images created during the caustic crossing can recombine with the others in different ways. This leads to a new classification of the microlensing events according to the behaviour of the images. We show that the images involved in these combinations depend on the folds that are crossed at the entry and at the exit from the caustic. Non-trivial trajectories can be classified into four main types. Some consequences for the motion of the center of light of the source in astrometric measurements are also examined.

  10. Every interacting double white dwarf binary may merge

    E-Print Network [OSTI]

    Shen, Ken J

    2015-01-01T23:59:59.000Z

    Interacting double white dwarf binaries can give rise to a wide variety of astrophysical outcomes ranging from faint thermonuclear and Type Ia supernovae to the formation of neutron stars and stably accreting AM Canum Venaticorum systems. One key factor affecting the final outcome is whether mass transfer remains dynamically stable or instead diverges, leading to the tidal disruption of the donor and the merger of the binary. It is typically thought that for low ratios of the donor mass to the accretor mass, mass transfer remains stable, especially if accretion occurs via a disk. In this Letter, we examine disk-accreting binaries with extremely low mass ratios and find that the initial phase of hydrogen-rich mass transfer leads to a classical nova-like outburst on the accretor. Dynamical friction within the expanding nova shell shrinks the orbit and causes the mass transfer rate to increase dramatically above the accretor's Eddington limit, resulting in a binary merger. While further calculations are necessar...

  11. The economic effects of elevated and depressed freeways on adjacent property owners

    E-Print Network [OSTI]

    Scurry, Floyd David

    1995-01-01T23:59:59.000Z

    ABSTRACT The Economic EfFects of Elevated and Depressed Freeways on The Adjacent Property Owners. (May 1995) Floyd David Sentry, B. S. , Texas AkM University Chair of Advisory Committee: Dr. Daniel B. Fambro An econonuc assessment of a comnunity... 322, 095 283, 680 283, 680 260, 040 3, 327, 330 $5, 005, 770 Net Effect of Highway on Property Values $4, 275 139, 635 185, 310 262, 145 254, 800 271, 680 257, 840 3, 327, 330 $4, 703, 095 23 The resale of homes at all levels showed...

  12. Solar PV Project Financing: Regulatory and Legislative Challenges for Third-Party PPA System Owners

    SciTech Connect (OSTI)

    Kollins, K.; Speer, B.; Cory, K.

    2009-11-01T23:59:59.000Z

    Residential and commercial end users of electricity who want to generate electricity using on-site solar photovoltaic (PV) systems face challenging initial and O&M costs. The third-party ownership power purchase agreement (PPA) finance model addresses these and other challenges. It allows developers to build and own PV systems on customers? properties and sell power back to customers. However, third-party electricity sales commonly face five regulatory challenges. The first three challenges involve legislative or regulatory definitions of electric utilities, power generation equipment, and providers of electric services. These definitions may compel third-party owners of solar PV systems to comply with regulations that may be cost prohibitive. Third-party owners face an additional challenge if they may not net meter, a practice that provides significant financial incentive to owning solar PV systems. Finally, municipalities and cooperatives worry about the regulatory implications of allowing an entity to sell electricity within their service territories. This paper summarizes these challenges, when they occur, and how they have been addressed in five states. This paper also presents alternative to the third-party ownership PPA finance model, including solar leases, contractual intermediaries, standardized contract language, federal investment tax credits, clean renewable energy bonds, and waived monopoly powers.

  13. A new detached K7 dwarf eclipsing binary system

    E-Print Network [OSTI]

    T. B. Young; M. G. Hidas; J. K. Webb; M. C. B. Ashley; J. L. Christiansen; A. Derekas; C. Nutto

    2007-03-22T23:59:59.000Z

    We present an analysis of a new, detached, double-lined eclipsing binary system with K7 Ve components, discovered as part of the University of New South Wales Extrasolar Planet Search. The object is significant in that only 6 other binary systems are known with comparable or lower mass. Such systems offer important tests of mass-radius theoretical models. Follow-up photometry and spectroscopy were obtained with the 40-inch and 2.3m telescopes at SSO respectively. An estimate of the radial velocity amplitude from spectral absorption features, combined with the orbital inclination (83.5 deg) estimated from lightcurve fitting, yielded a total mass of M=(1.041 +/- 0.06)M_sun and component masses of M_A=(0.529 +/- 0.035)M_sun and M_B=(0.512 +/- 0.035)M_sun. The radial velocity amplitude estimated from absorption features (167 +/- 3)kmps was found to be less than the estimate from the H_alpha emission lines (175 +/- 1.5)kmps. The lightcurve fit produced radii of R_A=(0.641 +/- 0.05)R_sun and R_B=(0.608 +/- 0.06)R_sun, and a temperature ratio of T_B/T_A=0.980 +/- 0.015. The apparent magnitude of the binary was estimated to be V=13.9 +/- 0.2. Combined with the spectral type, this gave the distance to the binary as 169 +/- 14 pc. The timing of the secondary eclipse gave a lower limit on the eccentricity of the binary system of 0.0025 +/- 0.0005. This is the most statistically significant non-zero eccentricity found for such a system, possibly suggesting the presence of a third companion.

  14. Compact binary mergers: an astrophysical perspective

    E-Print Network [OSTI]

    S. Rosswog

    2010-12-22T23:59:59.000Z

    This paper reviews the current understanding of double neutron star and neutron star black hole binaries. It addresses mainly (nuclear) astrophysics aspects of compact binary mergers and thus complements recent reviews that have emphasized the numerical relativity viewpoint. In particular, the paper discusses different channels to release neutron-rich matter into the host galaxy, connections between compact binary mergers and short Gamma-ray bursts and accompanying electromagnetic signals.

  15. Table HC1-5a. Housing Unit Characteristics by Type of Owner-Occupied Housing Unit,

    U.S. Energy Information Administration (EIA) 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells,1Stocks Nov-14Total DeliveredPrincipal shale gas:14: Totala.3a.5a.

  16. Table HC7-5a. Home Office Equipment by Type of Owner-Occupied Housing Unit,

    U.S. Energy Information Administration (EIA) 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTownDells,1Stocks Nov-14Total DeliveredPrincipal shale gas:14:9a.05a. Home

  17. Table HC1-5a. Housing Unit Characteristics by Type of Owner-Occupied Housing Unit,

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    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 33 111 1,613 122 40 Buildingto17questionnairesU.S. Weekly Download:Stocks by3a. Housing Unit5a.

  18. Table HC7-5a. Home Office Equipment by Type of Owner-Occupied Housing Unit,

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    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 33 111 1,613 122 40 Buildingto17questionnairesU.S. Weekly Download:Stocks by3a.7

  19. Approximate initial data for binary black holes

    E-Print Network [OSTI]

    Kenneth A. Dennison; Thomas W. Baumgarte; Harald P. Pfeiffer

    2006-08-26T23:59:59.000Z

    We construct approximate analytical solutions to the constraint equations of general relativity for binary black holes of arbitrary mass ratio in quasicircular orbit. We adopt the puncture method to solve the constraint equations in the transverse-traceless decomposition and consider perturbations of Schwarzschild black holes caused by boosts and the presence of a binary companion. A superposition of these two perturbations then yields approximate, but fully analytic binary black hole initial data that are accurate to first order in the inverse of the binary separation and the square of the black holes' momenta.

  20. Audit of joint owner costing and billing practices, Naval Petroleum Reserve No. 1, Elk Hills, California

    SciTech Connect (OSTI)

    Richards, J.R.

    1986-01-13T23:59:59.000Z

    The review showed a need for the Department to revise and strengthen cash management and cost allocation procedures and practices for jointly shared Reserve operating costs funded by the Government. The procedures and practices in effect for processing Joint Owner costs, billings and collections do not permit the Government to receive full advantage of the time value of money paid in behalf of Chevron or provide for the full sharing of all costs incurred by the Government to absorb unnecessary interest and operating costs since assuming responsibility for funding Reserve operations in October 1975. It is estimated that the Department would benefit by over $3 million per year if our recommendations in these areas are fully implemented.

  1. Pet owners have the responsibility to care for the well being of their animals. Your ability to

    E-Print Network [OSTI]

    Pet owners have the responsibility to care for the well being of their animals. Your ability to care for an animal can help determine what kind of animal you select as a pet. Out-of-Town Emergency Pamphlet, "Emergency Preparedness for Your Pets," 2003. Veterinarians in Your County or City Name

  2. Multifaceted Value Profiles of Forest Owner Categories in South Sweden: The River Helge a Catchment as a Case Study

    E-Print Network [OSTI]

    Vermont, University of

    -industrial forest land owners and municipalities included all value categories, the forest companies focused on wood including non-timber forest products as well as ecological, social, and cultural dimensions at multiple goods (e.g., timber and fish) can readily be converted into market goods. In contrast, many

  3. Channels and sources used to gather equine-related information by college-age horse owners and enthusiasts

    E-Print Network [OSTI]

    Sullivan, Erin Alene

    2009-05-15T23:59:59.000Z

    This thesis identifies the equine-related topics that are important to Texas college-age horse owners and enthusiasts and the channels/sources they use to get equine-related information. Little research has focused on this group to determine...

  4. Group Member Names: ________________________________________________ Scenario: You are the owner of a potato plant in Idaho. You have recently won a contract

    E-Print Network [OSTI]

    Provancher, William

    : ________________________________________________ ________________________________________________ ________________________________________________ Scenario: You are the owner of a potato plant in Idaho. You have recently won a contract to supply McDonald's with potatoes. McDonald's requires their suppliers to precut and freeze the potatoes before shipping to their distributing center. Your potato plant does not currently have a process for precutting and freezing potatoes

  5. The Evolution of Compact Binary Star Systems

    E-Print Network [OSTI]

    Konstantin Postnov; Lev Yungelson

    2014-03-21T23:59:59.000Z

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact binary stars are expected to be the most important sources for the forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binary stars with NS and/or black components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically important thermonuclear SN Ia. We also consider AM CVn-stars which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  6. The apsidal motion in close binary stars

    E-Print Network [OSTI]

    B. V. Vasiliev

    2001-10-10T23:59:59.000Z

    It is usually accepted to consider an apsidal motion in binary stars as a direct confirmation that a substance inside stars is not uniformly distributed. It is shown in this paper that the apsidal motion in binary systems observation data is in a good agreement with an existence of uniform plasma cores inside stars if they consist of hydrogen-deuterium-helium mixture.

  7. X-Ray Binary Systems in the Small Magellanic Cloud

    E-Print Network [OSTI]

    P. Kahabka; W. Pietsch

    1997-06-09T23:59:59.000Z

    We present the result of a systematic search for spectrally hard and soft X-ray binary systems in the Small Magellanic Cloud (SMC). This search has been applied to ROSAT PSPC data (0.1-2.4 keV) collected during 9 pointed observations towards this galaxy covering a time span of 2 years from October 91 till October 93. Selection criteria have been defined in order to confine the sample of candidates. Finally 7 spectrally hard and 4 spectrally soft sources were selected from the list as candidates for binaries in the SMC. The sample is luminosity limited (>3.10**35 erg/s). SMC X-1 has been observed during a full binary orbit starting with a low-state covering an X-ray eclipse and emerging into a bright long-duration flare with two short-duration flares separated by 10 hours. The Be type transient SMC X-2 has been redetected with ROSAT. Variability has been found in the sources RX J0051.8-7231 and RX J0052.1-731 already discovered with Einstein. RX J0101.0-7206 has been discovered at the north-eastern boundary of the giant SMC HII region N66 during an X-ray outburst and half a year later during a quiescent phase. A variable source, RX J0049.1-7250, located north-east of the SMC supernova remnant N19 and which may either be an X-ray binary or an AGN turns out to be strongly absorbed. It may be located behind the SMC. If it is an X-ray binary then it radiates at the Eddington limit in the X-ray bright state. Another variable and hard X-ray source RX J0032.9-7348 has been discovered at the south-eastern border of the body of the SMC. A high mass X-ray binary nature is favored for this source. We searched for CAL87 like systems in the SMC catalog and found none. A new candidate supersoft source RX J0103.8-7254 has been detected. We cannot exclude that it is a foreground object.

  8. DUST GRAIN EVOLUTION IN SPATIALLY RESOLVED T TAURI BINARIES

    SciTech Connect (OSTI)

    Skemer, Andrew J.; Close, Laird M.; Hinz, Philip M.; Hoffmann, William F.; Males, Jared R. [Steward Observatory, Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Greene, Thomas P. [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2011-10-10T23:59:59.000Z

    Core-accretion planet formation begins in protoplanetary disks with the growth of small, interstellar medium dust grains into larger particles. The progress of grain growth, which can be quantified using 10 {mu}m silicate spectroscopy, has broad implications for the final products of planet formation. Previous studies have attempted to correlate stellar and disk properties with the 10 {mu}m silicate feature in an effort to determine which stars are efficient at grain growth. Thus far there does not appear to be a dominant correlated parameter. In this paper, we use spatially resolved adaptive optics spectroscopy of nine T Tauri binaries as tight as 0.''25 to determine if basic properties shared between binary stars, such as age, composition, and formation history, have an effect on dust grain evolution. We find with 90%-95% confidence that the silicate feature equivalent widths of binaries are more similar than those of randomly paired single stars, implying that shared properties do play an important role in dust grain evolution. At lower statistical significance, we find with 82% confidence that the secondary has a more prominent silicate emission feature (i.e., smaller grains) than the primary. If confirmed by larger surveys, this would imply that spectral type and/or binarity are important factors in dust grain evolution.

  9. The first pre-supersoft X-ray binary

    E-Print Network [OSTI]

    Parsons, S G; Gansicke, B T; Rebassa-Mansergas, A; Brahm, R; Zorotovic, M; Toloza, O; Pala, A F; Tappert, C; Bayo, A; Jordan, A

    2015-01-01T23:59:59.000Z

    We report the discovery of an extremely close white dwarf plus F dwarf main-sequence star in a 12 hour binary identified by combining data from the RAdial Velocity Experiment (RAVE) survey and the Galaxy Evolution Explorer (GALEX) survey. A combination of spectral energy distribution fitting and optical and Hubble Space Telescope ultraviolet spectroscopy allowed us to place fairly precise constraints on the physical parameters of the binary. The system, TYC 6760-497-1, consists of a hot Teff~21,500K, M~0.65Ms white dwarf and an F8 star (M~1.23Ms, R~1.35Rs) seen at a low inclination (i~35 deg). The system is likely the descendent of a binary that contained the F star and a ~2Ms A-type star that filled its Roche-lobe on the second asymptotic giant branch, initiating a common envelope phase. The F star is extremely close to Roche-lobe filling and there is likely to be a short phase of thermal timescale mass-transfer onto the white dwarf. During this phase it will grow in mass by up to 20 per cent, until the mass...

  10. Binary vapor-liquid equilibrium data without measurement of composition

    E-Print Network [OSTI]

    Nehzat, Mohammad Sadegh

    1975-01-01T23:59:59.000Z

    . Blak- ley for their assistance in serving as committee members and for their constructive criticisms of this thesis. The help rendered by Mr. B. Bala)i Singh in typing this thesis is appreciated. vii TABLE OF CONTENTS ABSTRACT. ACKNOWLZDGEMENTS...NUZ DO 300 J=1, NT NPV=NP(J, N) READ(MR, 100) (V(I)=1&NPV) FORMAT(5F10 ~ 5) NPP=NP(J, N) DO 301 I=1, NPP RHO(I, J, N)=1. 00/V(I) GONTINUZ THIS PART READS DATA FOR SATURATION ENVELOPES OF EACH BINARY MIXTURE READ& KMINS(N) & KMAXS(N) KMINT...

  11. Distinguishing compact binary population synthesis models using gravitational-wave observations of coalescing binary black holes

    E-Print Network [OSTI]

    Stevenson, Simon; Fairhurst, Stephen

    2015-01-01T23:59:59.000Z

    The coalescence of compact binaries containing neutron stars or black holes is one of the most promising signals for advanced ground-based laser interferometer gravitational-wave detectors, with the first direct detections expected over the next few years. The rate of binary coalescences and the distribution of component masses is highly uncertain, and population synthesis models predict a wide range of plausible values. Poorly constrained parameters in population synthesis models correspond to poorly understood astrophysics at various stages in the evolution of massive binary stars, the progenitors of binary neutron star and binary black hole systems. These include effects such as supernova kick velocities, parameters governing the energetics of common envelope evolution and the strength of stellar winds. Observing multiple binary black hole systems through gravitational waves will allow us to infer details of the astrophysical mechanisms that lead to their formation. We simulate gravitational-wave observati...

  12. Safety Evaluation Report related to Hydrogen Control Owners Group assessment of Mark 3 containments

    SciTech Connect (OSTI)

    Li, C.Y.; Kudrick, J.A.

    1990-10-01T23:59:59.000Z

    Title 10 of the Code of Federal Regulations (10 CFR), Section 50.44 Standards for Combustible Gas Control System in Light-Water-Cooled Power Reactors,'' requires that systems be provided to control hydrogen concentration in the containment atmosphere following an accident to ensure that containment integrity is maintained. The purpose of this report is to provide regulatory guidance to licensees with Mark III containments with regard to demonstrating compliance with 10 CFR 50.44, Section (c)(3)(vi) and (c)(3)(vii). In this report, the staff provides its evaluation of the generic methodology proposed by the Hydrogen Control Owners Group. This generic methodology is documented in Topical Report HGN-112-NP, Generic Hydrogen Control Information for BWR/6 Mark III Containments.'' In addition, the staff has recommended that the vulnerability to interruption of power to the hydrogen igniters be evaluated further on a plant-specific basis as part of the individual plant examination of the plants with Mark III containments. 10 figs., 1 tab.

  13. The first light-curve analysis of eclipsing binaries observed by the INTEGRAL/OMC

    E-Print Network [OSTI]

    P. Zasche

    2008-04-24T23:59:59.000Z

    Three Algol-type binaries in Cygnus constellation were selected for an analysis from a huge database of observations made by the INTEGRAL/OMC camera. These data were processed and analyzed, resulting in a first light-curve study of these neglected eclipsing binaries. The temperatures of the primary components range from 9500 K to 10500 K and the inclinations are circa 73deg (for PV Cyg and V1011 Cyg), while almost 90deg for V822 Cyg. All of them seem to be main-sequence stars, well within their critical Roche lobes. Nevertheless, further detailed analyses are still needed.

  14. Logic Design Chapter 1: Binary Numbers

    E-Print Network [OSTI]

    Wu, Xiaolin

    of four bits: nibble A group of eight bits: byte Conversion between Decimal and Binary Converting least-significant bit (LSB) The left most bit is called the most significant bit (MSB) A group

  15. Binary Tomography with Deblurring Stefan Weber1

    E-Print Network [OSTI]

    Schn枚rr, Christoph

    Binary Tomography with Deblurring Stefan Weber1 , Thomas Sch篓ule1,3 , Attila Kuba2 , and Christoph-Verlag Berlin Heidelberg 2006 #12;376 S. Weber et al. quality of the reconstructed images. The correction

  16. BAYESIAN RESIDUAL ANALYSIS FOR BINARY RESPONSE

    E-Print Network [OSTI]

    Albert, James H.

    of Mathematics and Statistics Bowling Green State University, Bowling Green, 43403 USA Siddhartha Chib Olin School of Business Washington University, St. Louis 63130 USA March, 1994 Summary In a binary response

  17. ROTATIONAL DOPPLER BEAMING IN ECLIPSING BINARIES

    SciTech Connect (OSTI)

    Groot, Paul J., E-mail: pgroot@astro.ru.nl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2012-01-20T23:59:59.000Z

    In eclipsing binaries the stellar rotation of the two components will cause a rotational Doppler beaming during eclipse ingress and egress when only part of the eclipsed component is covered. For eclipsing binaries with fast spinning components this photometric analog of the well-known spectroscopic Rossiter-McLaughlin effect can exceed the strength of the orbital effect. Example light curves are shown for a detached double white dwarf binary, a massive O-star binary and a transiting exoplanet case, similar to WASP-33b. Inclusion of the rotational Doppler beaming in eclipsing systems is a prerequisite for deriving the correct stellar parameters from fitting high-quality photometric light curves and can be used to determine stellar obliquities as well as, e.g., an independent measure of the rotational velocity in those systems that may be expected to be fully synchronized.

  18. Gravitational waves from merging compact binaries

    E-Print Network [OSTI]

    Hughes, Scott A.

    Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. ...

  19. Faced with rising fuel costs, building and home owners are looking for energy-efficient solutions. Improving the building envelope (roof or attic system, walls,

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    and envelope assemblies for use in new construction and retrofits. Patrick Hughes Director, Building better understanding of product performance by the entire construction materials industry. INNOVATIONSFaced with rising fuel costs, building and home owners are looking for energy- efficient solutions

  20. Text-Alternative Version: The L Prize-Winning LED A19 Replacement梂hat Commercial Building Owners/Operators Can Expect in 2012

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "The L Prize-Winning LED A19 Replacement梂hat Commercial Building Owners/Operators Can Expect in 2012" webcast, held January 18, 2012.

  1. Legislating the rights of private property owners: a review and analysis of actions in the 103rd and 104th Congresses

    E-Print Network [OSTI]

    Kerby, Hannah Elizabeth

    1995-01-01T23:59:59.000Z

    LEGISLATING THE RIGHTS OF PRIVATE PROPERTY OWNERS: A REVIEW AND ANALYSIS OF ACTIONS IN THE 103RD AND 104TH CONGRESSES A Professional Paper by Hannah Elizabeth Kerby Approved as to style and content by: hairman, Advisory Committee Committee... Member Committee Member August 1995 Record of Study LEGISLATING THE RIGHTS OF PRIVATE PROPERTY OWNERS: A REVIEW AND ANALYSIS OF ACTIONS IN THE 103RD AND 104TH CONGRESSES A PROFESSIONAL PAPER by Hannah Elizabeth Kerby Submitted to the College...

  2. The close binary properties of massive stars in the Milky Way and low-metallicity Magellanic Clouds

    SciTech Connect (OSTI)

    Moe, Maxwell; Di Stefano, Rosanne, E-mail: mmoe@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-10, Cambridge, MA 02138 (United States)

    2013-12-01T23:59:59.000Z

    In order to understand the rates and properties of Type Ia and Type Ib/c supernovae, X-ray binaries, gravitational wave sources, and gamma-ray bursts as a function of galactic environment and cosmic age, it is imperative that we measure how the close binary properties of O- and B-type stars vary with metallicity. We have studied eclipsing binaries with early B main-sequence primaries in three galaxies with different metallicities: the Large and Small Magellanic Clouds (LMC and SMC, respectively) and the Milky Way (MW). The observed fractions of early B stars that exhibit deep eclipses 0.25 < ?m (mag) < 0.65 and orbital periods 2 < P (days) < 20 in the MW, LMC, and SMC span a narrow range of (0.7-1.0)%, which is a model-independent result. After correcting for geometrical selection effects and incompleteness toward low-mass companions, we find for early B stars in all three environments (1) a close binary fraction of (22 5)% across orbital periods 2 < P (days) < 20 and mass ratios q = M {sub 2}/M {sub 1} > 0.1, (2) an intrinsic orbital period distribution slightly skewed toward shorter periods relative to a distribution that is uniform in log P, (3) a mass-ratio distribution weighted toward low-mass companions, and (4) a small, nearly negligible excess fraction of twins with q > 0.9. Our fitted parameters derived for the MW eclipsing binaries match the properties inferred from nearby, early-type spectroscopic binaries, which further validates our results. There are no statistically significant trends with metallicity, demonstrating that the close binary properties of massive stars do not vary across metallicities 0.7 < log(Z/Z {sub ?}) < 0.0 beyond the measured uncertainties.

  3. Formation of contact in massive close binaries

    E-Print Network [OSTI]

    S. Wellstein; N. Langer; H. Braun

    2001-02-14T23:59:59.000Z

    We present evolutionary calculations for 74 close binaries systems with initial primary masses in the range 12...25 M_sun, and initial secondary masses between 6 and 24 M_sun. The initial periods were chosen such that mass overflow starts during the core hydrogen burning phase of the primary (Case A), or shortly thereafter (Case B). We assume conservative evolution for contact-free systems, i.e., no mass or angular momentum loss from those system except due to stellar winds. We investigate the borderline between contact-free evolution and contact, as a function of the initial system parameters. We also investigate the effect of the treatment of convection, and found it relevant for contact and supernova order in Case A systems, particularly for the highest considered masses. For Case B systems we find contact for initial periods above approximate 10 days and below. However, in that case (and for not too large periods) contact occurs only after the mass ratio has been reversed, due to the increased fraction of the donor's convective envelope. As most In all Cases we find contact for mass ratios below approximate 0.65. We derive the observable properties of our systems after the major mass transfer event, where the mass gainer is a main sequence or supergiant O or early B type star, and the mass loser is a helium star. We point out that the assumption of conservative evolution for contact-free systems could be tested by finding helium star companions to O stars.

  4. Connecting Distributed Energy Resources to the Grid: Their Benefits to the DER Owner etc.

    SciTech Connect (OSTI)

    Poore, WP

    2003-07-09T23:59:59.000Z

    The vision of the Distributed Energy Research Program (DER) program of the U.S. Department of Energy (DOE) is that the United States will have the cleanest and most efficient and reliable energy system in the world by maximizing the use of affordable distributed energy resources. Electricity consumers will be able to choose from a diverse number of efficient, cost-effective, and environmentally friendly distributed energy options and easily connect them into the nation's energy infrastructure while providing benefits to their owners and other stakeholders. The long-term goal of this vision is that DER will achieve a 20% share of new electric capacity additions in the United States by 2010, thereby helping to make the nation's electric power generation and delivery system more efficient, reliable, secure, clean, economical, and diverse in terms of fuel use (oil, natural gas, solar, hydroelectric, etc.) and prime mover resource (solar, wind, gas turbines, etc.). Near- and mid-term goals are to develop new technologies for implementing and operating DER and address barriers associated with DER usage and then to reduce costs and emissions and improve the efficiency and reliability of DER. Numerous strategies for meeting these goals have been developed into a research, development, and demonstration (RD&D) program that supports generation and delivery systems architecture, including modeling and simulation tools. The benefits associated with DER installations are often significant and numerous. They almost always provide tangible economic benefits, such as energy savings or transmission and distribution upgrade deferrals, as well as intangible benefits, such as power quality improvements that lengthen maintenance or repair intervals for power equipment. Also, the benefits routinely are dispersed among end users, utilities, and the public. For instance, an end user may use the DER to reduce their peak demand and save money due to lower demand charges. Reduced end user peak demand, in turn, may lower a distribution system peak load such that upgrades are deferred or avoided. This could benefit other consumers by providing them with higher reliability and power quality as well as avoiding their cost share of a distribution system upgrade. In this example, the costs of the DER may be born by the end user, but that user reaps only a share of the benefits. This report, the first product of a study to quantify the value of DER, documents initial project efforts to develop an assessment methodology. The focus of currently available site-specific DER assessment techniques are typically limited to two parties, the owner/user and the local utility. Rarely are the impacts on other stakeholders, including interconnected distribution utilities, transmission system operators, generating system operators, other local utility customers, local and regional industry and business, various levels of government, and the environment considered. The goal of this assessment is to quantify benefits and cost savings that accrue broadly across a region, recognizing that DER installations may have local, regional, or national benefits.

  5. Selection effects in resolving Galactic binaries with LISA

    E-Print Network [OSTI]

    M. J. Benacquista; S. L. Larson; B. E. Taylor

    2007-03-01T23:59:59.000Z

    Using several realisations of the Galactic population of close white dwarf binaries, we have explored the selection bias for resolved binaries in the LISA data stream. We have assumed a data analysis routine that is capable of identifying binaries that have a signal to noise ratio of at least 5 above a confusion foreground of unresolved binaries. The resolved population of binaries is separated into a subpopulation over 1000 binaries that have a measureable chirp and another subpopulation over 20,000 binaries that do not. As expected, the population of chirping binaries is heavily skewed toward high frequency, high chirp mass systems, with little or no preference for nearby systems. The population of non-chirping binaries is still biased toward frequencies above about 1 mHz. There is an overabundance of higher mass systems than is present in the complete Galactic population.

  6. Transcriptional leakage versus noise: A simple mechanism of conversion between binary and graded response in autoregulated genes

    E-Print Network [OSTI]

    Anna Ochab-Marcinek; Marcin Tabaka

    2015-01-16T23:59:59.000Z

    We study the response of an autoregulated gene to a range of concentrations of signal molecules. We show that transcriptional leakage and noise due to translational bursting have the opposite effects. In a positively autoregulated gene, increasing the noise converts the response from graded to binary, while increasing the leakage converts the response from binary to graded. Our findings support the hypothesis that, being a common phenomenon, leaky expression may be a relatively easy way for evolutionary tuning of the type of gene response without changing the type of regulation from positive to negative.

  7. Properties of planets in binary systems. The role of binary separation

    E-Print Network [OSTI]

    S. Desidera; M. Barbieri

    2006-10-20T23:59:59.000Z

    The statistical properties of planets in binaries were investigated. Any difference to planets orbiting single stars can shed light on the formation and evolution of planetary systems. As planets were found around components of binaries with very different separation and mass ratio, it is particularly important to study the characteristics of planets as a function of the effective gravitational influence of the companion. A compilation of planets in binary systems was made; a search for companions orbiting stars recently shown to host planets was performed, resulting in the addition of two further binary planet hosts (HD 20782 and HD 109749). The probable original properties of the three binary planet hosts with white dwarfs companions were also investigated. Using this updated sample of planets in binaries we performed a statistical analysis of the distributions of planet mass, period, and eccentricity, fraction of multiplanet systems, and stellar metallicity for planets orbiting components of tight and wide binaries and single stars. The only highly significant difference revealed by our analysis concerns the mass distribution of short-period planets. Massive planets in short period orbits are found in most cases around the components of rather tight binaries. The properties of exoplanets orbiting the components of wide binaries are compatible with those of planets orbiting single stars, except for a possible greater abundance of high-eccentricity planets. The previously suggested lack of massive planets with P>100 days in binaries is not confirmed. We conclude that the presence of a stellar companion with separation smaller than 100-300 AU is able to modify the formation and/or migration and/or the dynamical evolution history of giant planets while wide companions play a more limited role

  8. SELF-REGULATED SHOCKS IN MASSIVE STAR BINARY SYSTEMS

    SciTech Connect (OSTI)

    Parkin, E. R.; Sim, S. A., E-mail: parkin@mso.anu.edu.au, E-mail: s.sim@qub.ac.uk [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia)

    2013-04-20T23:59:59.000Z

    In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L{sub X}, remains largely unaltered, with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L{sub X}/L{sub bol}). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).

  9. KEPLER ECLIPSING BINARY STARS. III. CLASSIFICATION OF KEPLER ECLIPSING BINARY LIGHT CURVES WITH LOCALLY LINEAR EMBEDDING

    SciTech Connect (OSTI)

    Matijevic, Gal [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Prsa, Andrej [Department of Astronomy and Astrophysics, Villanova University, 800 E Lancaster Ave, Villanova, PA 19085 (United States); Orosz, Jerome A.; Welsh, William F. [Department of Astronomy, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182 (United States); Bloemen, Steven [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Barclay, Thomas, E-mail: gal.matijevic@fmf.uni-lj.si, E-mail: andrej.prsa@villanova.edu [NASA Ames Research Center/BAER Institute, Moffett Field, CA 94035 (United States)

    2012-05-15T23:59:59.000Z

    We present an automated classification of 2165 Kepler eclipsing binary (EB) light curves that accompanied the second Kepler data release. The light curves are classified using locally linear embedding, a general nonlinear dimensionality reduction tool, into morphology types (detached, semi-detached, overcontact, ellipsoidal). The method, related to a more widely used principal component analysis, produces a lower-dimensional representation of the input data while preserving local geometry and, consequently, the similarity between neighboring data points. We use this property to reduce the dimensionality in a series of steps to a one-dimensional manifold and classify light curves with a single parameter that is a measure of 'detachedness' of the system. This fully automated classification correlates well with the manual determination of morphology from the data release, and also efficiently highlights any misclassified objects. Once a lower-dimensional projection space is defined, the classification of additional light curves runs in a negligible time and the method can therefore be used as a fully automated classifier in pipeline structures. The classifier forms a tier of the Kepler EB pipeline that pre-processes light curves for the artificial intelligence based parameter estimator.

  10. The Binary White Dwarf LHS 3236

    E-Print Network [OSTI]

    Harris, Hugh; Dupuy, Trent; Canzian, Blaise; Guetter, Harry; Hartkopf, William; Ireland, Michael; Leggett, Sandy; Levine, Stephen; Liu, Michael; Luginbuhl, Christian; Monet, Alice; Stone, Ronald; Subasavage, John; Tilleman, Trudy; Walker, Richard

    2013-01-01T23:59:59.000Z

    The white dwarf LHS 3236 (WD1639+153) is shown to be a double-degenerate binary, with each component having a high mass. Astrometry at the U.S. Naval Observatory gives a parallax and distance of 30.86 +/- 0.25 pc and a tangential velocity of 98 km/s, and reveals binary orbital motion. The orbital parameters are determined from astrometry of the photocenter over more than three orbits of the 4.0-year period. High-resolution imaging at the Keck Observatory resolves the pair with a separation of 31 and 124 mas at two epochs. Optical and near-IR photometry give a set of possible binary components. Consistency of all data indicates that the binary is a pair of DA stars with temperatures near 8000 and 7400 K and with masses of 0.93 and 0.91 M_solar; also possible, is a DA primary and a helium DC secondary with temperatures near 8800 and 6000 K and with masses of 0.98 and 0.69 M_solar. In either case, the cooling ages of the stars are ~3 Gyr and the total ages are <4 Gyr. The combined mass of the binary (1.66--1....

  11. The binary white dwarf LHS 3236

    SciTech Connect (OSTI)

    Harris, Hugh C.; Dahn, Conard C.; Canzian, Blaise; Guetter, Harry H.; Levine, Stephen E.; Luginbuhl, Christian B.; Monet, Alice K. B.; Stone, Ronald C.; Subasavage, John P.; Tilleman, Trudy; Walker, Richard L. [US Naval Observatory, 10391 West Naval Observatory Road, Flagstaff, AZ 86001-8521 (United States); Dupuy, Trent J.; Liu, Michael C. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hartkopf, William I. [US Naval Observatory, 3450 Massachusetts Avenue, N.W., Washington, DC 20392-5420 (United States); Ireland, Michael J. [Department of Physics and Astronomy, Macquarie University, New South Wales, NSW 2109 (Australia); Leggett, S. K., E-mail: hch@nofs.navy.mil [Gemini Observatory, 670 N. Aohoku Place, Hilo, HI 96720 (United States)

    2013-12-10T23:59:59.000Z

    The white dwarf LHS 3236 (WD1639+153) is shown to be a double-degenerate binary, with each component having a high mass. Astrometry at the U.S. Naval Observatory gives a parallax and distance of 30.86 0.25 pc and a tangential velocity of 98 km s{sup 1}, and reveals binary orbital motion. The orbital parameters are determined from astrometry of the photocenter over more than three orbits of the 4.0 yr period. High-resolution imaging at the Keck Observatory resolves the pair with a separation of 31 and 124 mas at two epochs. Optical and near-IR photometry give a set of possible binary components. Consistency of all data indicates that the binary is a pair of DA stars with temperatures near 8000 and 7400 K and with masses of 0.93 and 0.91 M {sub ?}; also possible is a DA primary and a helium DC secondary with temperatures near 8800 and 6000 K and with masses of 0.98 and 0.69 M {sub ?}. In either case, the cooling ages of the stars are ?3 Gyr and the total ages are <4 Gyr. The combined mass of the binary (1.66-1.84 M {sub ?}) is well above the Chandrasekhar limit; however, the timescale for coalescence is long.

  12. Investigating Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2009-06-08T23:59:59.000Z

    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

  13. Guide to Combined Heat and Power Systems for Boiler Owners and Operators

    SciTech Connect (OSTI)

    Oland, CB

    2004-08-19T23:59:59.000Z

    Combined heat and power (CHP) or cogeneration is the sequential production of two forms of useful energy from a single fuel source. In most CHP applications, chemical energy in fuel is converted to both mechanical and thermal energy. The mechanical energy is generally used to generate electricity, while the thermal energy or heat is used to produce steam, hot water, or hot air. Depending on the application, CHP is referred to by various names including Building Cooling, Heating, and Power (BCHP); Cooling, Heating, and Power for Buildings (CHPB); Combined Cooling, Heating, and Power (CCHP); Integrated Energy Systems (IES), or Distributed Energy Resources (DER). The principal technical advantage of a CHP system is its ability to extract more useful energy from fuel compared to traditional energy systems such as conventional power plants that only generate electricity and industrial boiler systems that only produce steam or hot water for process applications. By using fuel energy for both power and heat production, CHP systems can be very energy efficient and have the potential to produce electricity below the price charged by the local power provider. Another important incentive for applying cogeneration technology is to reduce or eliminate dependency on the electrical grid. For some industrial processes, the consequences of losing power for even a short period of time are unacceptable. The primary objective of the guide is to present information needed to evaluate the viability of cogeneration for new or existing industrial, commercial, and institutional (ICI) boiler installations and to make informed CHP equipment selection decisions. Information presented is meant to help boiler owners and operators understand the potential benefits derived from implementing a CHP project and recognize opportunities for successful application of cogeneration technology. Topics covered in the guide follow: (1) an overview of cogeneration technology with discussions about benefits of applying cogeneration technology and barriers to implementing cogeneration technology; (2) applicable federal regulations and permitting issues; (3) descriptions of prime movers commonly used in CHP applications, including discussions about design characteristics, heat-recovery options and equipment, fuels and emissions, efficiency, maintenance, availability, and capital cost; (4) electrical generators and electrical interconnection equipment; (5) cooling and dehumidification equipment; (6) thermodynamic cycle options and configurations; (7) steps for evaluating the technical and economic feasibility of applying cogeneration technology; and (8) information sources.

  14. TeV neutrinos from microquasars in compact massive binaries

    E-Print Network [OSTI]

    W. Bednarek

    2005-05-27T23:59:59.000Z

    We consider a compact binary system in which a Wolf-Rayet star supplies matter onto a stellar mass black hole or a neutron star. This matter forms an accretion disk which ejects a jet as observed in Galactic microquasars. A part of the jet kinetic energy, typically 10%, can be transfered to relativistic nuclei. These nuclei lose nucleons as a result of photo-disintegration process in collisions with thermal photons from the accretion disk and the massive star. Due to the head on photon-nucleus collisions most of neutrons released from nuclei move towards the surface of the accretion disk and/or the massive star producing neutrinos in collisions with the matter. We calculate the spectra of muon neutrinos and expected neutrino event rates in a 1 km^2 neutrino detector of the IceCube type from a microquasar inside our Galaxy applying, as an example, the parameters of the Cyg X-3 binary system, provided that nuclei are accelerated to the Lorentz factors above 10^6 with the power law spectrum with an index close to 2.

  15. CV evolution: AM Her binaries and the period gap

    E-Print Network [OSTI]

    R. F. Webbink; D. T. Wickramasinghe

    2002-04-19T23:59:59.000Z

    AM Her variables -- synchronised magnetic cataclysmic variables (CVs) -- exhibit a different period distribution from other CVs across the period gap. We show that non-AM Her systems may infiltrate the longer-period end of the period gap if they are metal-deficient, but that the position and width of the gap in orbital period is otherwise insensitive to other binary parameters (excepting the normalisation of the braking rate). In AM Her binaries, magnetic braking is reduced as the wind from the secondary star may be trapped within the magnetosphere of the white dwarf primary. This reduced braking fills the period gap from its short-period end as the dipole magnetic moment of the white dwarf increases. The consistency of these models with the observed distribution of CVs, both AM Her and non-AM Her type, provides compelling evidence supporting magnetic braking as the agent of angular momentum loss among long-period CVs, and its disruption as the explanation of the 2 - 3 hour period gap among nonmagnetic CVs.

  16. Are owners' reports of their dogs 慻uilty look influenced by the dogs action and evidence of the misdeed?

    E-Print Network [OSTI]

    Ostoji?, Ljerka; Tkal?i?, Mladenka; Clayton, Nicola S.

    2015-01-03T23:59:59.000Z

    dogs greeting behaviours were not a Thus, our findings do not support th concurrent negative reaction by their 2015 The Authors. Published bylocate /behavproc uenced by the dogs nija 4, 51000 Rijeka Croatia eeting behaviour after having performed a... dogs that have eaten the r whom the food was not replaced by the experimenter lude that their dog had performed the misdeed. ls and methods s ix owners and their dogs were tested in Croatia from 011 to January 2012 and from June to October 2013 (see...

  17. Tracking Multiple Targets Using Binary Decisions from Wireless Sensor Networks

    E-Print Network [OSTI]

    Michailidis, George

    Tracking Multiple Targets Using Binary Decisions from Wireless Sensor Networks Natallia Katenka- tions. 1 #12;Keywords: wireless sensor networks, binary data, target tracking, multiple targets, penal- ized maximum likelihood 1 Introduction and Problem Motivation Wireless Sensor Networks (WSN) have

  18. Binary Capture Rates for Massive Protostars

    E-Print Network [OSTI]

    Nickolas Moeckel; John Bally

    2007-04-09T23:59:59.000Z

    The high multiplicity of massive stars in dense, young clusters is established early in their evolution. The mechanism behind this remains unresolved. Recent results suggest that massive protostars may capture companions through disk interactions with much higher efficiency than their solar mass counterparts. However, this conclusion is based on analytic determinations of capture rates and estimates of the robustness of the resulting binaries. We present the results of coupled n-body and SPH simulations of star-disk encounters to further test the idea that disk-captured binaries contribute to the observed multiplicity of massive stars.

  19. Binary Evolution in World Wide Web

    E-Print Network [OSTI]

    S. N. Nazin; V. M. Lipunov; I. E. Panchenko; K. A. Postnov; M. E. Prokhorov; S. B. Popov

    1996-05-29T23:59:59.000Z

    We present a WWW-version of the {\\it Scenario Machine} - a computer code designed to calculate the evolution of close binary stellar systems. The Internet users can directly access to the code and calculate binary evolutionary tracks with parameters at the user's will. The program is running on the {\\it Pentium} server of the Division of the Relativistic Astrophysics of the Sternberg Astronimical Institute (http://xray.sai.msu.su/ ). The results are presented both in the form of tables and graphic diagrams. The work is always in progress. More possibilities for Internet users are intended to become available in the near future.

  20. RESEARCH Open Access Multi-non-binary turbo codes

    E-Print Network [OSTI]

    Paris-Sud XI, Universit茅 de

    RESEARCH Open Access Multi-non-binary turbo codes Horia Balta1,2 , Catherine Douillard3 and Radu Lucaciu1* Abstract This paper presents a new family of turbo codes called multi-non-binary turbo codes (MNBTCs) that generalizes the concept of turbo codes to multi-non-binary (MNB) parallel concatenated

  1. Jitter Equalization for Binary Baseband Communication

    E-Print Network [OSTI]

    Chan Carusone, Tony

    Jitter Equalization for Binary Baseband Communication Anthony Chan Carusone Department reduces pattern- dependent jitter. Instead of using the LMS or a related algorithm that optimizes at data transitions, thereby targeting zero jitter. The LMS algorithm is modified to combine the two

  2. Binary power multiplier for electromagnetic energy

    DOE Patents [OSTI]

    Farkas, Zoltan D. (203 Leland Ave., Menlo Park, CA 94025)

    1988-01-01T23:59:59.000Z

    A technique for converting electromagnetic pulses to higher power amplitude and shorter duration, in binary multiples, splits an input pulse into two channels, and subjects the pulses in the two channels to a number of binary pulse compression operations. Each pulse compression operation entails combining the pulses in both input channels and selectively steering the combined power to one output channel during the leading half of the pulses and to the other output channel during the trailing half of the pulses, and then delaying the pulse in the first output channel by an amount equal to half the initial pulse duration. Apparatus for carrying out each of the binary multiplication operation preferably includes a four-port coupler (such as a 3 dB hybrid), which operates on power inputs at a pair of input ports by directing the combined power to either of a pair of output ports, depending on the relative phase of the inputs. Therefore, by appropriately phase coding the pulses prior to any of the pulse compression stages, the entire pulse compression (with associated binary power multiplication) can be carried out solely with passive elements.

  3. Binary translation using peephole translation rules

    DOE Patents [OSTI]

    Bansal, Sorav; Aiken, Alex

    2010-05-04T23:59:59.000Z

    An efficient binary translator uses peephole translation rules to directly translate executable code from one instruction set to another. In a preferred embodiment, the translation rules are generated using superoptimization techniques that enable the translator to automatically learn translation rules for translating code from the source to target instruction set architecture.

  4. Principal Components Analysis for Binary Data

    E-Print Network [OSTI]

    Lee, Seokho

    2010-07-14T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix CHAPTER I INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Formulations of Principal Components Analysis . . . . . . . . 2 1.2 Generalization of Sparse Principal Components Analysis to Binary Variables... . . . . . . . . . . . . . . . . . . . . . . . . 8 1.3 Review of Estimation Procedures . . . . . . . . . . . . . . . . 11 1.4 Overview of Dissertation . . . . . . . . . . . . . . . . . . . . . 18 II SPARSE PRINCIPAL COMPONENTS ANALYSIS FOR BI- NARY DATA...

  5. An airport owner or operator is responsible for maintaining many elements on the air-

    E-Print Network [OSTI]

    Minnesota, University of

    to read, interpret, and use a pavement inspection report. WHAT IS PREVENTIVE MAINTENANCE? Increasing maintenance operations: Preventive maintenance: Applied to surfaces to improve or extend a pave- ment maintenance program. Preventive maintenance is generally the least expensive type of maintenance

  6. Non-binary Entanglement-assisted Stabilizer Quantum Codes

    E-Print Network [OSTI]

    Leng Riguang; Ma Zhi

    2011-05-30T23:59:59.000Z

    In this paper, we show how to construct non-binary entanglement-assisted stabilizer quantum codes by using pre-shared entanglement between the sender and receiver. We also give an algorithm to determine the circuit for non-binary entanglement-assisted stabilizer quantum codes and some illustrated examples. The codes we constructed do not require the dual-containing constraint, and many non-binary classical codes, like non-binary LDPC codes, which do not satisfy the condition, can be used to construct non-binary entanglement-assisted stabilizer quantum codes.

  7. Observable fractions of core-collapse supernova light curves brightened by binary companions

    E-Print Network [OSTI]

    Moriya, Takashi J; Izzard, Robert G

    2015-01-01T23:59:59.000Z

    Many core-collapse supernova progenitors are presumed to be in binary systems. If a star explodes in a binary system, the early supernova light curve can be brightened by the collision of the supernova ejecta with the companion star. The early brightening can be observed when the observer is in the direction of the hole created by the collision. Based on a population synthesis model, we estimate the fractions of core-collapse supernovae in which the light-curve brightening by the collision can be observed. We find that 0.19% of core-collapse supernova light curves can be observed with the collisional brightening. Type Ibc supernova light curves are more likely to be brightened by the collision (0.53%) because of the high fraction of the progenitors being in binary systems and their proximity to the companion stars. Type II and IIb supernova light curves are less affected (~1e-3% and ~1e-2%, respectively). Although the early, slow light-curve declines of some Type IIb and Ibc supernovae are argued to be caused...

  8. Infrared Spectroscopy of the Ultra Low Mass Binary Oph 162225-240515

    E-Print Network [OSTI]

    Alexis Brandeker; Ray Jayawardhana; Valentin D. Ivanov; Radostin Kurtev

    2006-10-19T23:59:59.000Z

    Binary properties are an important diagnostic of the star and brown dwarf formation processes. While wide binaries appear to be rare in the sub-stellar regime, recent observations have revealed Ophiuchus 162225-240515 (2MASS J16222521-2405139) as a likely young ultra-low-mass binary with an apparent separation of ~240 AU. Here, we present low-resolution near-infrared spectra of the pair from NTT/SOFI (R~600) and VLT/ISAAC (R~1400), covering the 1.0-2.5um spectral region. By comparing to model atmospheres from Chabrier & Baraffe and Burrows et al., we confirm the surface temperatures to be T_A = (2350+/-150) K and T_B = (2100+/-100) K for the two components of the binary, consistent with earlier estimates from optical spectra. Using gravity sensitive K I features, we find the surface gravity to be significantly lower than field dwarfs of the same spectral type, providing the best evidence so far that these objects are indeed young. However, we find that models are not sufficiently reliable to infer accurate ages/masses from surface gravity. Instead, we derive masses of M_A = 13 (+8/-4) M_J and M_B = 10 (+5/-4) M_J for the two objects using the well-constrained temperatures and assuming an age of 1-10 Myr, consistent with the full range of ages reported for the Oph region.

  9. Detached white-dwarf close-binary stars -- CV's extended family

    E-Print Network [OSTI]

    T. R. Marsh

    1999-06-07T23:59:59.000Z

    I review detached binaries consisting of white dwarfs with either other white dwarfs or low mass main-sequence stars in tight orbits around them. Orbital periods have been measured for 15 white dwarf/white dwarf systems and 22 white dwarf/M dwarf systems. While small compared to the number of periods known for CVs (>300), I argue that each variety of detached system has a space density an order of magnitude higher that of CVs. While theory matches the observed distribution of orbital periods of the white dwarf/white dwarf binaries, it predicts white dwarfs of much lower mass than observed. Amongst both types of binary are clear examples of helium core white dwarfs, as opposed to the usual CO composition; similar systems must exist amongst the CVs. White dwarf/M dwarf binaries suffer from selection effects which diminish the numbers seen at long and short periods. They are useful for the study of irradiation; I discuss evidence to suggest that Balmer emission is broadened by optical depth effects to an extent which limits its usefulness for imaging the secondary stars in CVs.

  10. AN X-RAY AND OPTICAL LIGHT CURVE MODEL OF THE ECLIPSING SYMBIOTIC BINARY SMC3

    SciTech Connect (OSTI)

    Kato, Mariko [Department of Astronomy, Keio University, Hiyoshi, Yokohama 223-8521 (Japan)] [Department of Astronomy, Keio University, Hiyoshi, Yokohama 223-8521 (Japan); Hachisu, Izumi [Department of Earth Science and Astronomy, College of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)] [Department of Earth Science and Astronomy, College of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Mikolajewska, Joanna, E-mail: mariko@educ.cc.keio.ac.jp [Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warszawa (Poland)] [Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warszawa (Poland)

    2013-01-20T23:59:59.000Z

    Some binary evolution scenarios for Type Ia supernovae (SNe Ia) include long-period binaries that evolve to symbiotic supersoft X-ray sources in their late stage of evolution. However, symbiotic stars with steady hydrogen burning on the white dwarf's (WD) surface are very rare, and the X-ray characteristics are not well known. SMC3 is one such rare example and a key object for understanding the evolution of symbiotic stars to SNe Ia. SMC3 is an eclipsing symbiotic binary, consisting of a massive WD and red giant (RG), with an orbital period of 4.5 years in the Small Magellanic Cloud. The long-term V light curve variations are reproduced as orbital variations in the irradiated RG, whose atmosphere fills its Roche lobe, thus supporting the idea that the RG supplies matter to the WD at rates high enough to maintain steady hydrogen burning on the WD. We also present an eclipse model in which an X-ray-emitting region around the WD is almost totally occulted by the RG swelling over the Roche lobe on the trailing side, although it is always partly obscured by a long spiral tail of neutral hydrogen surrounding the binary in the orbital plane.

  11. THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

    SciTech Connect (OSTI)

    Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St, Cambridge, MA 02138 (United States); Kilic, Mukremin; Gianninas, A. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK, 73019 (United States); Allende Prieto, Carlos, E-mail: wbrown@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: kilic@ou.edu, E-mail: alexg@nhn.ou.edu, E-mail: callende@iac.es [Instituto de Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain)

    2013-05-20T23:59:59.000Z

    We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P {<=} 1 day) binaries. Our sample includes four objects with remarkable log g {approx_equal} 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times <10 Gyr. Four have {approx}>0.9 M{sub Sun} companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

  12. Gas pile-up, gap overflow, and Type 1.5 migration in circumbinary disks: general theory

    E-Print Network [OSTI]

    Bence Kocsis; Zoltan Haiman; Abraham Loeb

    2012-09-13T23:59:59.000Z

    Many astrophysical binaries, from planets to black holes, exert strong torques on their circumbinary accretion disks, and are expected to significantly modify the disk structure. Despite the several decade long history of the subject, the joint evolution of the binary + disk system has not been modeled with self-consistent assumptions for arbitrary mass ratios and accretion rates. Here we solve the coupled binary-disk evolution equations analytically in the strongly perturbed limit, treating the azimuthally-averaged angular momentum exchange between the disk and the binary and the modifications to the density, scale-height, and viscosity self-consistently, including viscous and tidal heating, diffusion limited cooling, radiation pressure, and the orbital decay of the binary. We find a solution with a central cavity and a migration rate similar to those previously obtained for Type-II migration, applicable for large masses and binary separations, and near-equal mass ratios. However, we identify a distinct new regime, applicable at smaller separations and masses, and mass ratio in the range 0.001piles up outside the binary's orbit, but rather than creating a cavity, it continuously overflows as in a porous dam. The disk profile is intermediate between a weakly perturbed disk (producing Type-I migration) and a disk with a gap (with Type-II migration). However, the migration rate of the secondary is typically slower than both Type-I and Type-II rates. We term this new regime "Type-1.5" migration.

  13. Evolution of Close Neutron Star Binaries

    E-Print Network [OSTI]

    W. Ogawaguchi; Y. Kojima

    1996-10-17T23:59:59.000Z

    We have calculated evolution of neutron star binaries towards the coalescence driven by gravitational radiation. The hydrodynamical effects as well as the general relativistic effects are important in the final phase. All corrections up to post$^{2.5}$-Newtonian order and the tidal effect are included in the orbital motion. The star is approximated by a simple Newtonian stellar model called affine star model. Stellar spins and angular momentum are assumed to be aligned. We have showed how the internal stellar structure affects the stellar deformation, variations of the spins, and the orbital motion of the binary just before the contact. The gravitational wave forms from the last a few revolutions significantly depend on the stellar structure.

  14. Long-Term Stability of Planets in Binary Systems

    E-Print Network [OSTI]

    Matthew Holman; Paul Wiegert

    1998-09-24T23:59:59.000Z

    A simple question of celestial mechanics is investigated: in what regions of phase space near a binary system can planets persist for long times? The planets are taken to be test particles moving in the field of an eccentric binary system. A range of values of the binary eccentricity and mass ratio is studied, and both the case of planets orbiting close to one of the stars, and that of planets outside the binary orbiting the system's center of mass, are examined. From the results, empirical expressions are developed for both 1) the largest orbit around each of the stars, and 2) the smallest orbit around the binary system as a whole, in which test particles survive the length of the integration (10^4 binary periods). The empirical expressions developed, which are roughly linear in both the mass ratio mu and the binary eccentricity e, are determined for the range 0.0 <= e <= 0.7-0.8 and 0.1 <= mu <= 0.9 in both regions, and can be used to guide searches for planets in binary systems. After considering the case of a single low-mass planet in binary systems, the stability of a mutually-interacting system of planets orbiting one star of a binary system is examined, though in less detail.

  15. Automated pupil remapping with binary optics

    DOE Patents [OSTI]

    Neal, Daniel R. (Tijeras, NM); Mansell, Justin (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    Methods and apparatuses for pupil remapping employing non-standard lenslet shapes in arrays; divergence of lenslet focal spots from on-axis arrangements; use of lenslet arrays to resize two-dimensional inputs to the array; and use of lenslet arrays to map an aperture shape to a different detector shape. Applications include wavefront sensing, astronomical applications, optical interconnects, keylocks, and other binary optics and diffractive optics applications.

  16. Automated pupil remapping with binary optics

    DOE Patents [OSTI]

    Neal, D.R.; Mansell, J.

    1999-01-26T23:59:59.000Z

    Methods and apparatuses are disclosed for pupil remapping employing non-standard lenslet shapes in arrays; divergence of lenslet focal spots from on-axis arrangements; use of lenslet arrays to resize two-dimensional inputs to the array; and use of lenslet arrays to map an aperture shape to a different detector shape. Applications include wavefront sensing, astronomical applications, optical interconnects, keylocks, and other binary optics and diffractive optics applications. 24 figs.

  17. Gravitational lensing in eclipsing binary stars

    E-Print Network [OSTI]

    T. R. Marsh

    2000-12-18T23:59:59.000Z

    I consider the effect of the gravitational deflection of light upon the light curves of eclipsing binary stars, focussing mainly upon systems containing at least one white dwarf component. In absolute terms the effects are small, however they are strongest at the time of secondary eclipse when the white dwarf transits its companion, and act to reduce the depth of this feature. If not accounted for, this may lead to under-estimation of the radius of the white dwarf compared to that of its companion. I show that the effect is significant for plausible binary parameters, and that it leads to ~25% reduction in the transit depth in the system KPD 1930+2752. The reduction of eclipse depth is degenerate with the stellar radius ratio, and therefore cannot be used to establish the existence of lensing. A second order effect of the light bending is to steepen the ingress and egress features of the secondary eclipse relative to the primary eclipse, although it will be difficult to see this in practice. I consider also binaries containing neutron stars and black-holes. I conclude that, although relatively large effects are possible in such systems, a combination of rarity, faintness and intrinsic variability make it unlikely that lensing will be detectable in them.

  18. Phase equilibrium measurements on twelve binary mixtures

    SciTech Connect (OSTI)

    Giles, N.F. [Wiltec Research Co., Inc., Provo, UT (United States)] [Wiltec Research Co., Inc., Provo, UT (United States); Wilson, H.L.; Wilding, W.V. [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.

    1996-11-01T23:59:59.000Z

    Phase equilibrium measurements have been performed on twelve binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following binary systems at two temperatures each: ethanethiol + propylene; nitrobenzene + methanol; pyridine + ethyl acetate; octane + tert-amyl methyl ether; diisopropyl ether + butane; 1,3-dichloro-2-propanol + epichlorohydrin; 2,3-dichloro-1-propanol + epichlorohydrin; 2,3-epoxy-1-propanol + epichlorohydrin; 3-chloro-1,2-propanediol + epichlorohydrin; methanol + hydrogen cyanide. For these systems, equilibrium vapor and liquid phase compositions were derived from the PTx data using the Soave equation of state to represent the vapor phase and the Wilson, NRTL, or Redlich-Kister activity coefficient model to represent the liquid phase. The infinite dilution activity coefficient of methylamine in N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone-rich half of the binary. Liquid-liquid equilibrium studies were made on the triethylene glycol + 1-pentene system at two temperatures by directly analyzing samples taken from each liquid phase.

  19. Hot Works Procedures and Protocols Last Updated: 2/14/2014 Owner: Safety and Risk Management Director Page 1 of 6

    E-Print Network [OSTI]

    Dyer, Bill

    Hot Works Procedures and Protocols Last Updated: 2/14/2014 Owner: Safety and Risk Management Management Director Page 2 of 6 start and stop times, and location of work. The Office of Work Control and Risk Management reserves the right to inspect all Hot Works areas, and revoke authorizations

  20. Faced with rising fuel costs, building and home owners are looking for energy-efficient solutions. Improving the building envelope (roof or attic system, walls,

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    and envelope assemblies for use in new construction and retrofits. Patrick Hughes Director, Building materials industry. INNOVATIONS IN BUILDINGS Contact ORNL 2012-G00695/tcc Ensuring Affordable, EfficientFaced with rising fuel costs, building and home owners are looking for energy- efficient solutions

  1. KUALI TIPS FOR CAPITAL ASSETS NEW OBJECT CODES: These are based upon the Funding Source Code. Owner Field shows Title now.

    E-Print Network [OSTI]

    KUALI TIPS FOR CAPITAL ASSETS NEW OBJECT CODES: These are based upon the Funding Source Code. Owner Field shows Title now. Decal # Historical Sub Code New Object Code Description Comments OBJECT CODES: To determine which Object Code you should use, you will need to look up the Account Fund

  2. KUALI TIPS FOR CAPITAL ASSETS NEW OBJECT CODES: These are based upon Funding Source vs. Title. Owner Field shows Title now.

    E-Print Network [OSTI]

    KUALI TIPS FOR CAPITAL ASSETS NEW OBJECT CODES: These are based upon Funding Source vs. Title. Owner Field shows Title now. Decal # Historical Sub Code New Object Code Description 3 8210 8210 CSU) and 8247 (Federal Loaned) are Property Use Only. HOW TO USE THE NEW OBJECT CODES: To determine which Object

  3. The Guaranteed Maximum Price proposal is developed at the phase specified in the Agreement Between Owner and Construction Manager, usually at 50% Construction Documents.

    E-Print Network [OSTI]

    Sura, Philip

    Owner and Construction Manager, usually at 50% Construction Documents. The GMP proposal should be bound general summary of scope of work, alternates, etc.) Tab 2 List of documents (project manual(s), drawings summary of the work, the construction manager's fee (as identified in Paragraph 7.2 of the Agreement) must

  4. Targeting the optimal design in randomized clinical trials with binary outcomes and no covariate

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Targeting the optimal design in randomized clinical trials with binary outcomes and no covariate of randomized clinical trials with binary treatment, binary outcome and no covariate. By adaptive design, we designs in the case of randomized clinical trials with binary treatment, binary outcome and no covariate

  5. Collisional Hardening of Compact Binaries in Globular Clusters

    E-Print Network [OSTI]

    S. Banerjee; P. Ghosh

    2006-09-29T23:59:59.000Z

    We consider essential mechanisms for orbit-shrinkage or "hardening" of compact binaries in globular clusters to the point of Roche-lobe contact and X-ray emission phase, focussing on the process of collisional hardening due to encounters between binaries and single stars in the cluster core. The interplay between this kind of hardening and that due to emission of gravitational radiation produces a characteristic scaling of the orbit-shrinkage time with the single-star binary encounter rate $\\gamma$ in the cluster which we introduce, clarify, and explore. We investigate possible effects of this scaling on populations of X-ray binaries in globular clusters within the framework of a simple "toy" scheme for describing the evolution of pre-X-ray binaries in globular clusters. We find the expected qualitative trends sufficiently supported by data on X-ray binaries in galactic globular clusters to encourage us toward a more quantitative study.

  6. Spiral Disk Instability Can Drive Thermonuclear Explosions in Binary White Dwarf Mergers

    E-Print Network [OSTI]

    Kashyap, Rahul; Garc韆-Berro, Enrique; Aznar-Sigu醤, Gabriela; Ji, Suoqing; Lor閚-Aguilar, Pablo

    2015-01-01T23:59:59.000Z

    Thermonuclear, or Type Ia supernovae (SNe Ia), originate from the explosion of carbon-oxygen white dwarfs, and serve as standardizable cosmological candles. However, despite their importance, the nature of the progenitor systems which give rise to SNe Ia has not been hitherto elucidated. Observational evidence favors the double-degenerate channel, in which merging white dwarf binaries lead to SNe Ia. Furthermore, significant discrepancies exist between observations and theory, and to date, there has been no self-consistent merger model which yields a SNe Ia. Here we show that a spiral mode instability in the accretion disk formed during a binary white dwarf merger leads to a detonation on a dynamical timescale. This mechanism sheds light on how white dwarf mergers may frequently yield SNe Ia.

  7. Angular momentum exchange in white dwarf binaries accreting through direct impact

    SciTech Connect (OSTI)

    Sepinsky, J. F. [Department of Physics and Electrical Engineering, The University of Scranton, Scranton, PA 18510 (United States); Kalogera, V., E-mail: jeremy.sepinsky@scranton.edu, E-mail: vicky@northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2014-04-20T23:59:59.000Z

    We examine the exchange of angular momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binary systems. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular momentum transfer depends on the binary properties, particularly the masses of the double white dwarf binary component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.

  8. Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries

    E-Print Network [OSTI]

    Lars Bildsten; Ken J. Shen; Nevin N. Weinberg; Gijs Nelemans

    2007-05-06T23:59:59.000Z

    Helium that accretes onto a Carbon/Oxygen white dwarf in the double white dwarf AM Canum Venaticorum (AM CVn) binaries undergoes unstable thermonuclear flashes when the orbital period is in the 3.5-25 minute range. At the shortest orbital periods (and highest accretion rates, Mdot > 10^-7 Msol/yr), the flashes are weak and likely lead to the Helium equivalent of classical nova outbursts. However, as the orbit widens and Mdot drops, the mass required for the unstable ignition increases, leading to progressively more violent flashes up to a final flash with Helium shell mass ~ 0.02-0.1 Msol. The high pressures of these last flashes allow the burning to produce the radioactive elements 48Cr, 52Fe, and 56Ni that power a faint (M_V in the range of -15 to -18) and rapidly rising (few days) thermonuclear supernova. Current galactic AM CVn space densities imply one such explosion every 5,000-15,000 years in 10^11 Msol of old stars (~ 2-6% of the Type Ia rate in E/SO galaxies). These ".Ia" supernovae (one-tenth as bright for one-tenth the time as a Type Ia supernovae) are excellent targets for deep (e.g. V=24) searches with nightly cadences, potentially yielding an all-sky rate of 1,000 per year.

  9. Strong Field of Binary Systems And Its Effects On Pulsar Arrival Times

    E-Print Network [OSTI]

    M. I. Wanas; N. S. Awadalla; W. S. El Hanafy

    2012-10-05T23:59:59.000Z

    In the present work, the exact solution of Einstein's field equations which has been given by Curzon in 1924 representing the field of a static binary system is reviewed. An adapted version of this solution is obtained to describe a dynamical binaries in a rotating coordinate system. It is shown that this version of the solution is time-dependent. It reduces to the later one in the static case if the rotation goes to zero. The original Curzon solution shows that there are two singularities at the two masses, while in the modified version the singularities become on the world-line of the two masses. The solution shows no additional coordinate singularities. The killing vector field of the axial symmetry is obtained in the modified version. In addition, the rotation admits a further rotational symmetry, so a rotation killing vector field is also obtained and discussed. The equations of motion for a test particle in the field of a binary system are formulated and solved. Such equations have been used to study the gravitational time delay of arrival (Shapiro delay) of signals from binary pulsar systems resulted from our suggested modifications containing additional terms. These terms are interpreted as higher order corrections to the masses. In particular we investigate the gravito-magnetic effect due to orbital angular motion of the double pulsars. We give numerical estimates of this type of the time delay in the case of the double-pulsar system PSR J0737-3039 A/B. We draw a model curve for the gravito-magnetic time delay during one orbital revolution. We suggest that this type of delay will have a larger contribution during the last phase of the system evolution.

  10. The Relativistic Binary Pulsar B1913+16

    E-Print Network [OSTI]

    J. M. Weisberg; J. H. Taylor

    2002-11-11T23:59:59.000Z

    We describe the results of a relativistic analysis of our observations of binary pulsar B1913+16, up to the latest measurements in 2001 August.

  11. Binary Decision Rules for Multistage Adaptive Mixed-Integer ...

    E-Print Network [OSTI]

    2014-08-20T23:59:59.000Z

    Aug 20, 2014 ... In the first test series, we compared the performance of the binary decision rules versus the non- ..... involving indicator functions is NP-hard.

  12. Spectroscopic Binary Mass Determination using Relativity

    E-Print Network [OSTI]

    Zucker, S; Zucker, Shay; Alexander, Tal

    2006-01-01T23:59:59.000Z

    High-precision radial-velocity techniques, which enabled the detection of extrasolar planets are now sensitive to relativistic effects in the data of spectroscopic binary stars (SBs). We show how these effects can be used to derive the absolute masses of the components of eclipsing single-lined SBs and double-lined SBs from Doppler measurements alone. High-precision stellar spectroscopy can thus substantially increase the number of measured sellar masses, thereby improving the mass-radius and mass-magnitude calibrations.

  13. Spectroscopic Binary Mass Determination using Relativity

    E-Print Network [OSTI]

    Shay Zucker; Tal Alexander

    2006-11-14T23:59:59.000Z

    High-precision radial-velocity techniques, which enabled the detection of extrasolar planets are now sensitive to relativistic effects in the data of spectroscopic binary stars (SBs). We show how these effects can be used to derive the absolute masses of the components of eclipsing single-lined SBs and double-lined SBs from Doppler measurements alone. High-precision stellar spectroscopy can thus substantially increase the number of measured stellar masses, thereby improving the mass-radius and mass-luminosity calibrations.

  14. Binary Cycle Power Plant | 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 EditCalifornia: EnergyAvignon,Belcher Homes JumpMaintenance |BigBig WindyWindBinary

  15. Dispersal of planets hosted in binaries, transitional members of multiple star systems

    E-Print Network [OSTI]

    F. Marzari; M. Barbieri

    2007-07-04T23:59:59.000Z

    This paper explains why planets in binary star systems might have a lower frequency. A transient triple state of the binary causes the dispersal of planets.

  16. Disk Evolution in Young Binaries: from Observations to Theory

    E-Print Network [OSTI]

    J. -L. Monin; C. J. Clarke; L. Prato; C. McCabe

    2006-04-03T23:59:59.000Z

    The formation of a binary system surrounded by disks is the most common outcome of stellar formation. Hence studying and understanding the formation and the evolution of binary systems and associated disks is a cornerstone of star formation science. Moreover, since the components within binary systems are coeval and the sizes of their disks are fixed by the tidal truncation of their companion, binary systems provide an ideal "laboratory" in which to study disk evolution under well defined boundary conditions. In this paper, we review observations of several inner disk diagnostics in multiple systems, including hydrogen emission lines (indicative of ongoing accretion), $K-L$ and $K-N$ color excesses (evidence of warm inner disks), and polarization (indicative of the relative orientations of the disks around each component). We examine to what degree these properties are correlated within binary systems and how this degree of correlation depends on parameters such as separation and binary mass ratio. These findings will be interpreted both in terms of models that treat each disk as an isolated reservoir and those in which the disks are subject to re-supply from some form of circumbinary reservoir, the observational evidence for which we will also critically review. The planet forming potential of multiple star systems is discussed in terms of the relative lifetimes of disks around single stars, binary primaries and binary secondaries. Finally, we summarize several potentially revealing observational problems and future projects that could provide further insight into disk evolution in the coming decade

  17. Layered Binary-Dielectrics for Energy Applications: Limitations and Potentials

    SciTech Connect (OSTI)

    Tuncer, Enis [ORNL

    2012-01-01T23:59:59.000Z

    In this Letter, an attempt is made to illustrate how performance of an electrically insulating material, a dielectric, can be improved by constructing a layered binary-dielectric structure that employs a weak insulator with high dielectric permittivity. It is shown that layered binary-dielectrics could have a signicant impact on energy storage and electrical insulation.

  18. Binary coding of Kekule structures of catacondensed benzenoid hydrocarbons

    E-Print Network [OSTI]

    Klavzar, Sandi

    Binary coding of Kekul麓e structures of catacondensed benzenoid hydrocarbons Sandi Klavzar of benzenoids Key words: benzenoid hydrocarbons, benzenoid graph, resonance graph, Kekul麓e structure, algorithm easily be recovered from its binary code. Key words: benzenoid hydrocarbons, benzenoid graph, resonance

  19. Binary coding of Kekule structures of catacondensed benzenoid hydrocarbons

    E-Print Network [OSTI]

    Klavzar, Sandi

    Binary coding of Kekul??e structures of catacondensed benzenoid hydrocarbons Sandi Klav鸥zar, a??e structures of benzenoids Key words: benzenoid hydrocarbons, benzenoid graph, resonance graph, Kekul easily be recovered from its binary code. Key words: benzenoid hydrocarbons, benzenoid graph, resonance

  20. Optimum Treatment Allocation for Dualobjective Clinical Trials with Binary Outcomes

    E-Print Network [OSTI]

    New York at Stoney Brook, State University of

    Optimum Treatment Allocation for Dual璷bjective Clinical Trials with Binary Outcomes Wei Zhu, Weng treatment allocation schemes are derived for multiple璷bjective clinical trials with binary outcome tients to various treatment groups in a randomized controlled clinical trial where the primary outcome

  1. Contemporary Mathematics The merit factor of binary sequence families

    E-Print Network [OSTI]

    Jedwab, Jonathan

    Contemporary Mathematics The merit factor of binary sequence families constructed from m-sequences sequence families obtained from an initial binary sequence family using a "negaperiodic" and a "periodic" construction. When the initial sequences are m-sequences, both of the constructed families have the same

  2. Surface tension in a reactive binary mixture of incompressible fluids

    E-Print Network [OSTI]

    Struchtrup, Henning

    Surface tension in a reactive binary mixture of incompressible fluids Henning Struchtrup Institute with a distributed form of surface tension. The model describes chemistry, diffusion, viscosity and heat transfer tension at the front. Keywords: Binary mixtures, Surface tension, Irreversible thermodynamics, Hele

  3. ccsd00004127, ON THE SURFACE TENSIONS OF BINARY MIXTURES

    E-Print Network [OSTI]

    ccsd颅00004127, version 1 颅 2 Feb 2005 ON THE SURFACE TENSIONS OF BINARY MIXTURES JEAN RUIZ Abstract tensions and the concentrations are brie y reviewed. Key Words: Surface tensions, binary mixtures the corresponding surface tension depends on the composition of the mixture. Some relationship is expected which

  4. Hamiltonian Hydrodynamics and Irrotational Binary Inspiral

    E-Print Network [OSTI]

    Charalampos M. Markakis

    2014-10-28T23:59:59.000Z

    Gravitational waves from neutron-star and black-hole binaries carry valuable information on their physical properties and probe physics inaccessible to the laboratory. Although development of black-hole gravitational-wave templates in the past decade has been revolutionary, the corresponding work for double neutron-star systems has lagged. Neutron stars can be well-modelled as simple barotropic fluids during the part of binary inspiral most relevant to gravitational wave astronomy, but the crucial geometric and mathematical consequences of this simplification have remained computationally unexploited. In particular, Carter and Lichnerowicz have described barotropic fluid motion via classical variational principles as conformally geodesic. Moreover, Kelvin's circulation theorem implies that initially irrotational flows remain irrotational. Applied to numerical relativity, these concepts lead to novel Hamiltonian or Hamilton-Jacobi schemes for evolving relativistic fluid flows. Hamiltonian methods can conserve not only flux, but also circulation and symplecticity, and moreover do not require addition of an artificial atmosphere typically required by standard conservative methods. These properties can allow production of high-precision gravitational waveforms at low computational cost. This canonical hydrodynamics approach is applicable to a wide class of problems involving theoretical or computational fluid dynamics.

  5. Electrodeposition of binary iron-group alloys

    SciTech Connect (OSTI)

    Sasaki, K.Y.; Talbot, J.B. [Univ. of California, San Diego, La Jolla, CA (United States)

    1995-03-01T23:59:59.000Z

    Thin films of NiCo and CoFe have been galvanostatically electroplated onto a platinum rotating disk electrode from simple sulfate baths containing 0.5M of the more noble metal sulfate and 0.1M of the less noble metal sulfate. The experimental results are compared to those of previous studies of NiFe codeposition in order to study the anomalous codeposition behavior of the binary iron-group alloys. Comparison of the electrodeposition results indicates that codeposition of these binary alloys is not totally analogous. It was found that codeposition of NiCo and NiFe show more mass-transfer effects than does CoFe deposition within the range of current densities studied. A model of anomalous codeposition put forth previously for NiFe was applied to the electrodeposition of NiCo and CoFe to determine the extensibility of the model, which assumes metal mono hydroxides, MOH{sup +}, are the important charge-transfer species. This model was unable to characterize fully either NiCo or CoFe electrodeposition. However, with minor changes to the hydrolysis constants used in the model, the model predictions were found to agree with the data for CoFe codeposition and greatly, improve the fit for the NiCo results.

  6. 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.

  7. DETERMINATION OF ORBITAL ELEMENTS OF SPECTROSCOPIC BINARIES USING HIGH-DISPERSION SPECTROSCOPY

    SciTech Connect (OSTI)

    Katoh, Noriyuki [Graduate School of Science, Kobe University, 1-1 Rokkoudai, Nada-ku, Kobe, Hyogo 657-8501 (Japan); Itoh, Yoichi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Sayo, Hyogo 679-5313 (Japan); Toyota, Eri [Kobe Science Museum, 7-7-6 Minatojimanakacho, Chou-ku, Kobe, Hyogo 650-0046 (Japan); Sato, Bun'ei [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-02-01T23:59:59.000Z

    Orbital elements of 37 single-lined spectroscopic binary systems (SB1s) and 5 double-lined spectroscopic binary systems (SB2s) were determined using high-dispersion spectroscopy. To determine the orbital elements accurately, we carried out precise Doppler shift measurements using the HIgh Dispersion Echelle Spectrograph mounted on the Okayama Astrophysical Observatory 1.88 m telescope. We achieved a radial-velocity precision of {approx}10 m s{sup -1} over seven years of observations. The targeted binaries have spectral types between F5 and K3, and are brighter than the 7th magnitude in the V band. The orbital elements of 28 SB1s and 5 SB2s were determined at least 10 times more precisely than previous measurements. Among the remaining nine SB1s, five objects were found to be single stars, and the orbital elements of four objects were not determined because our observations did not cover the entire orbital period. We checked the absorption lines from the secondary star for 28 SB1s and found that three objects were in fact SB2s.

  8. Magnetized Moving Mesh Merger of a Carbon-Oxygen White Dwarf Binary

    E-Print Network [OSTI]

    Zhu, Chenchong; van Kerkwijk, Marten H; Chang, Philip

    2015-01-01T23:59:59.000Z

    White dwarf binary mergers are possible progenitors to a number of unusual stars and transient phenomena, including type Ia supernovae. To date, simulations of mergers have not included magnetic fields, even though they are believed to play a significant role in the evolution of the merger remnant. We simulated a 0.625 - 0.65 $M_{\\odot}$ carbon-oxygen white dwarf binary merger in the magnetohydrodynamic moving mesh code Arepo. Each white dwarf was given an initial dipole field with a surface value of $\\sim10^3$ G. As in simulations of merging double neutron star binaries, we find exponential field growth within Kelvin-Helmholtz instability-generated vortices during the coalescence of the two stars. The final field has complex geometry, and a strength $>10^{10}$ G at the center of the merger remnant. Its energy is $\\sim2\\times10^{47}$ ergs, $\\sim0.2$% of the remnant's total energy. The strong field likely influences further evolution of the merger remnant by providing a mechanism for angular momentum transfer ...

  9. Binary classification of items of interest in a repeatable process

    DOE Patents [OSTI]

    Abell, Jeffrey A.; Spicer, John Patrick; Wincek, Michael Anthony; Wang, Hui; Chakraborty, Debejyo

    2014-06-24T23:59:59.000Z

    A system includes host and learning machines in electrical communication with sensors positioned with respect to an item of interest, e.g., a weld, and memory. The host executes instructions from memory to predict a binary quality status of the item. The learning machine receives signals from the sensor(s), identifies candidate features, and extracts features from the candidates that are more predictive of the binary quality status relative to other candidate features. The learning machine maps the extracted features to a dimensional space that includes most of the items from a passing binary class and excludes all or most of the items from a failing binary class. The host also compares the received signals for a subsequent item of interest to the dimensional space to thereby predict, in real time, the binary quality status of the subsequent item of interest.

  10. Absentee herd owners and part-time pastoralists: the political economy of resource use in northern Kenya

    SciTech Connect (OSTI)

    Little, P.D.

    1985-06-01T23:59:59.000Z

    The prevalence of absentee herd ownership in Africa's pastoral areas is increasing. Its presence has important implications both for local resource management systems and for research programs that address pastoral ecology and related topics. This paper examines patterns of absentee herd ownership in the Baringo District of northern Kenya. This region has been the source of much debate regarding herder ''mismanagement'' of range lands. Three categories of absentee herd owners are discussed in the paper: (1) ranchers, (2) livestock traders, and (3) townsmen. It is suggested that the blame for some of the apparent resource mismanagement in the region may lie more with actors in these categories than with the pastoralists themselves. Data collected during an 18-month period in 1980-1981 on pastoral ecology, grazing patterns, and tenure institutions are presented in support of the argument. The paper concludes with a comparative analysis of contemporary resource management strategies in pastoral Africa, emphasizing that: (1) the Baringo case is not an isolated anomaly, and (2) a new orientation toward pastoral studies is warranted.

  11. The B and W Owners Group program for microstructural characterization and radiation embrittlement modelling of Linde 80 reactor vessel welds

    SciTech Connect (OSTI)

    Pavinich, W.A. [Grove Engineering, Knoxville, TN (United States); Harbison, L.S. [B and W Nuclear Technologies, Lynchburg, VA (United States)

    1996-12-31T23:59:59.000Z

    The Babcock and Wilcox Owners Group (B and WOG) is embrittlement of Linde 80 reactor vessel welds from a micro-mechanical viewpoint. Previous work that focused on characterizing the large microstructural features indicated that a large portion of the bulk copper content is in precipitate/inclusion/carbide form. This result indicates that copper in solid solution is considerably less than the bulk composition. Field-ion microscope atom probe investigations on unirradiated weld metals with bulk copper contents ranging from 0.22 to 0.38 wt%, also indicate significant amount of copper are tied up in precipitate/inclusion/carbide form. This results is significant since the bulk copper content (which includes both copper in solid solution and copper contained in precipitates, inclusions, and carbides) is used in Regulatory Guide 1.99, Revision 2 to determine radiation damage. This paper reviews these results. Existing radiation embrittlement models superpose the changes in yield strength due to defect clusters and copper-rich precipitates induced by neutron irradiation. Low-copper Linde 80 welds display little or no increase in the 41 joule (30 ft-lb) transition temperature as a result of neutron irradiation which indicates that precipitation is the dominant component of radiation embrittlement for Linde 80 welds. Future work will include further microstructural characterizations of Linde 80 reactor vessel welds and applying the existing radiation embrittlement models to Linde 80 welds. This paper describes the detailed plans for future work.

  12. Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models

    E-Print Network [OSTI]

    Almog, Assaf

    2014-01-01T23:59:59.000Z

    The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of time series of activity of their fundamental elements (such as stocks or neurons respectively). While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relationships between binary and non-binary properties of financial time series. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to replicate the observed binary/non-binary relations very well, and to mathematically...

  13. The triple binary star EQ Tau with an active component

    SciTech Connect (OSTI)

    Li, K.; Hu, S.-M. [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Science and School of Space Science and Physics, Shandong University, Weihai, Weihai 264209 (China); Qian, S.-B.; He, J.-J., E-mail: kaili@sdu.edu.cn, E-mail: likai@ynao.ac.cn, E-mail: husm@sdu.edu.cn [Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)

    2014-05-01T23:59:59.000Z

    New photometric data of EQ Tau observed in 2010 and 2013 are presented. Light curves obtained in 2000 and 2004 by Yuan and Qian and 2001 by Yang and Liu, together with our two newly determined sets of light curves, were analyzed using the Wilson-Devinney code. The five sets of light curves exhibit very obvious variations, implying that the light curves of EQ Tau show a strong O'Connell effect. We found that EQ Tau is an A-type shallow contact binary with a contact degree of f = 11.8%; variable dark spots on the primary component of EQ Tau were also observed. Using 10 new times of minimum light, together with those collected from the literature, the orbital period change of EQ Tau was analyzed. We found that its orbital period includes a secular decrease (dP/dt = 3.63 10{sup 8} days yr{sup 1}) and a cyclic oscillation (A {sub 3} = 0.0058 days and P {sub 3} = 22.7 yr). The secular increase of the period can be explained by mass transfer from the more massive component to the less massive one or/and angular momentum loss due to a magnetic stellar wind. The Applegate mechanism cannot explain the cyclic orbital period change. A probable transit-like event was observed in 2010. Therefore, the cyclic orbital period change of EQ Tau may be due to the light time effect of a third body.

  14. COSMOLOGICAL FAST RADIO BURSTS FROM BINARY WHITE DWARF MERGERS

    SciTech Connect (OSTI)

    Kashiyama, Kazumi; M閟z醨os, Peter [Department of Astronomy and Astrophysics, Department of Physics, Center for Particle and Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)] [Department of Astronomy and Astrophysics, Department of Physics, Center for Particle and Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Ioka, Kunihito, E-mail: kzk15@psu.edu, E-mail: nnp@psu.edu, E-mail: kunihito.ioka@kek.jp [Theory Center, Institute of Particle and Nuclear Studies, KEK, Department of Particle and Nuclear Physics, the Graduate University for Advanced Studies (Sokendai), Tsukuba 305-0801 (Japan)] [Theory Center, Institute of Particle and Nuclear Studies, KEK, Department of Particle and Nuclear Physics, the Graduate University for Advanced Studies (Sokendai), Tsukuba 305-0801 (Japan)

    2013-10-20T23:59:59.000Z

    Recently, Thornton et al. reported the detection of four fast radio bursts (FRBs). The dispersion measures indicate that the sources of these FRBs are at cosmological distance. Given the large full sky event rate ?10{sup 4} sky{sup 1} day{sup 1}, the FRBs are a promising target for multi-messenger astronomy. Here we propose double degenerate, binary white-dwarf (WD) mergers as the source of FRBs, which are produced by coherent emission from the polar region of a rapidly rotating, magnetized massive WD formed after the merger. The basic characteristics of the FRBs, such as the energetics, emission duration and event rate, can be consistently explained in this scenario. As a result, we predict that some FRBs can accompany type Ia supernovae (SNe Ia) or X-ray debris disks. Simultaneous detection could test our scenario and probe the progenitors of SNe Ia, and moreover would provide a novel constraint on the cosmological parameters. We strongly encourage future SN and X-ray surveys that follow up FRBs.

  15. QU Car: a very high luminosity nova-like binary with a carbon-enriched companion

    E-Print Network [OSTI]

    J. E. Drew; L. E. Hartley; K. S. Long; J. van der Walt

    2002-09-16T23:59:59.000Z

    QU Car is listed in cataclysmic variable star catalogues as a nova-like variable. This little-studied, yet bright interacting binary is re-appraised here in the light of new high-quality ultraviolet (UV) interstellar line data obtained with STIS on board the Hubble Space Telescope. The detection of a component of interstellar absorption at a mean LSR velocity of $-$14 km s$^{-1}$ indicates that the distance to QU Car may be $\\sim$2 kpc or more -- a considerable increase on the previous lower-limiting distance of 500 pc. If so, the bolometric luminosity of QU Car could exceed $10^{37}$ ergs s$^{-1}$. This would place this binary in the luminosity domain occupied by known compact-binary supersoft X-ray sources. Even at a 500 pc, QU Car appears to be the most luminous nova-like variable known. New intermediate dispersion optical spectroscopy of QU Car spanning 3800--7000 \\AA is presented. These data yield the discovery that C{\\sc iv} $\\lambda\\lambda$5801,12 is present as an unusually prominent emission line in an otherwise low-contrast line spectrum. Using measurements of this and other lines in a recombination line analysis, it is shown that the C/He abundance as proxied by the n(C$^{4+}$)/n(He$^{2+}$) ratio may be as high as 0.06 (an order of magnitude higher than the solar ratio). Furthermore, the C/O abundance ratio is estimated to be greater than 1. These findings suggest that the companion in QU Car is a carbon star. If so, it would be the first example of a carbon star in such a binary. An early-type R star best matches the required abundance pattern and could escape detection at optical wavelengths provided the distance to QU Car is $\\sim$2 kpc or more.

  16. Award Types

    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 Office511041cloth DocumentationProductsAlternativeOperationalAugust AugustInstruments on theAward Types Types of

  17. Spatial distribution of luminous X-ray binaries in spiral galaxies

    E-Print Network [OSTI]

    Zhao-yu Zuo; Xiang-dong Li; Xi-wei Liu

    2008-06-02T23:59:59.000Z

    We have modelled the spatial distribution of luminous X-ray binaries (XRBs) in spiral galaxies that are like the Milky Way using an evolutionary population synthesis code. In agreement with previous theoretical expectations and observations, we find that both high- and low-mass XRBs show clear concentrations towards the galactic plane and bulge.We also compare XRB distributions under the galactic potential with a dark matter halo and the modified Newtonian dynamics potential, and we suggest that the difference may serve as potential evidence to discriminate between these two types of model.

  18. Debra N. Thompson, PhD, RN, NEA-BC Debra N. Thompson, PhD, RN, NEA-BC, owner and principal of Debra N. Thompson, LLC holds an

    E-Print Network [OSTI]

    Sibille, Etienne

    Debra N. Thompson, PhD, RN, NEA-BC Biosketch Debra N. Thompson, PhD, RN, NEA-BC, owner and principal of Debra N. Thompson, LLC holds an Adjunct Faculty appointment as an Assistant Professor

  19. GSC 07396-00759 = V4046 Sgr C[D]: A WIDE-SEPARATION COMPANION TO THE CLOSE T TAURI BINARY SYSTEM V4046 Sgr AB

    E-Print Network [OSTI]

    Kastner, J. H.

    We explore the possibility that GSC 07396-00759 (spectral type M1e) is a widely separated (~2[' over .]82, or projected separation ~12,350 AU) companion to the "old" (age ~12 Myr) classical T Tauri binary system V4046 Sgr ...

  20. Phase equilibrium measurements on nine binary mixtures

    SciTech Connect (OSTI)

    Wilding, W.V. [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.; Giles, N.F.; Wilson, L.C. [Wiltec Research Co. Inc., Provo, UT (United States)] [Wiltec Research Co. Inc., Provo, UT (United States)

    1996-11-01T23:59:59.000Z

    Phase equilibrium measurements have been performed on nine binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following systems at two temperatures each: (aminoethyl)piperazine + diethylenetriamine; 2-butoxyethyl acetate + 2-butoxyethanol; 2-methyl-2-propanol + 2-methylbutane; 2-methyl-2-propanol + 2-methyl-2-butene; methacrylonitrile + methanol; 1-chloro-1,1-difluoroethane + hydrogen chloride; 2-(hexyloxy)ethanol + ethylene glycol; butane + ammonia; propionaldehyde + butane. Equilibrium vapor and liquid phase compositions were derived form the PTx data using the Soave equation of state to represent the vapor phase and the Wilson or the NRTL activity coefficient model to represent the liquid phase. A large immiscibility region exists in the butane + ammonia system at 0 C. Therefore, separate vapor-liquid-liquid equilibrium measurements were performed on this system to more precisely determine the miscibility limits and the composition of the vapor phase in equilibrium with the two liquid phases.

  1. Mapping the peculiar binary GP Com

    E-Print Network [OSTI]

    L. Morales-Rueda; T. R. Marsh; R. C. North

    2000-08-29T23:59:59.000Z

    We present high resolution spectra of the AM CVn helium binary GP Com at two different wavelength ranges. The spectra show the same flaring behaviour observed in previous UV and optical data. We find that the central spike contributes to the flare spectra indicating that its origin is probably the compact object. We also detect that the central spike moves with orbital phase following an S-wave pattern. The radial velocity semiamplitude of the S-wave is \\~10 km/s which indicates its origin is near the centre of mass of the system, which in this case lies very close to the white dwarf. The Stark effect seems to affect significantly the central spike of some of the lines suggesting that it forms in a high electron density region. This again favours the idea that the central spike originates in the white dwarf. We present Doppler maps obtained for the emission lines which show three clear emission regions.

  2. Mapping the peculiar binary GP Com

    E-Print Network [OSTI]

    Morales-Rueda, L; North, R C

    2000-01-01T23:59:59.000Z

    We present high resolution spectra of the AM CVn helium binary GP Com at two different wavelength ranges. The spectra show the same flaring behaviour observed in previous UV and optical data. We find that the central spike contributes to the flare spectra indicating that its origin is probably the compact object. We also detect that the central spike moves with orbital phase following an S-wave pattern. The radial velocity semiamplitude of the S-wave is \\~10 km/s which indicates its origin is near the centre of mass of the system, which in this case lies very close to the white dwarf. The Stark effect seems to affect significantly the central spike of some of the lines suggesting that it forms in a high electron density region. This again favours the idea that the central spike originates in the white dwarf. We present Doppler maps obtained for the emission lines which show three clear emission regions.

  3. Dynamical evolution of active detached binaries on log Jo - log M diagram and contact binary formation

    E-Print Network [OSTI]

    Z. Eker; O. Demircan; S. Bilir; Y. Karatas

    2006-09-14T23:59:59.000Z

    Orbital angular momentum (Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of log Jo - log P, log M - log P and log Jo-log M were formed from 119 CAB and 102 W UMa stars. The log Jo-log M diagram is found to be most meaningful in demonstrating dynamical evolution of binary star orbits. A slightly curved borderline (contact border) separating the detached and the contact systems was discovered on the log Jo - log M diagram. Since orbital size (a) and period (P) of binaries are determined by their current Jo, M and mass ratio q, the rates of orbital angular momentum loss (dlog Jo/dt) and mass loss (dlog M/dt) are primary parameters to determine the direction and the speed of the dynamical evolution. A detached system becomes a contact system if its own dynamical evolution enables it to pass the contact border on the log Jo - log M diagram. Evolution of q for a mass loosing detached system is unknown unless mass loss rate for each component is known. Assuming q is constant in the first approximation and using the mean decreasing rates of Jo and M from the kinematical ages of CAB stars, it has been predicted that 11, 23 and 39 cent of current CAB stars would transform to W UMa systems if their nuclear evolution permits them to live 2, 4 and 6 Gyrs respectively.

  4. REFINED METALLICITY INDICES FOR M DWARFS USING THE SLoWPoKES CATALOG OF WIDE, LOW-MASS BINARIES

    SciTech Connect (OSTI)

    Dhital, Saurav; Stassun, Keivan G.; Bastien, Fabienne A. [Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN 37235 (United States); West, Andrew A.; Massey, Angela P. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Bochanski, John J., E-mail: saurav.dhital@vanderbilt.edu [Astronomy and Astrophysics Department, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2012-03-15T23:59:59.000Z

    We report the results from spectroscopic observations of 113 ultra-wide, low-mass binary systems, largely composed of M0-M3 dwarfs, from the SLoWPoKES catalog of common proper motion pairs identified in the Sloan Digital Sky Survey. Radial velocities of each binary member were used to confirm that they are comoving and, consequently, to further validate the high fidelity of the SLoWPoKES catalog. Ten stars appear to be spectroscopic binaries based on broad or split spectral features, supporting previous findings that wide binaries are likely to be hierarchical systems. We measured the H{alpha} equivalent width of the stars in our sample and found that components of 81% of the observed pairs have similar H{alpha} levels. The difference in H{alpha} equivalent width among components with similar masses was smaller than the range of H{alpha} variability for individual objects. We confirm that the Lepine et al. {zeta}-index traces iso-metallicity loci for most of our sample of M dwarfs. However, we find a small systematic bias in {zeta}, especially in the early-type M dwarfs. We use our sample to recalibrate the definition of {zeta}. While representing a small change in the definition, the new {zeta} is a significantly better predictor of iso-metallicity for the higher-mass M dwarfs.

  5. Analysis of the methods for the derivation of binary kinetic equations in the theory of fluorescence concentration quenching

    SciTech Connect (OSTI)

    Doktorov, A. B. [Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia and Physics Department Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2014-09-14T23:59:59.000Z

    In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.

  6. The dominant X-ray wind in massive star binaries

    E-Print Network [OSTI]

    J. M. Pittard; I. R. Stevens

    2002-04-15T23:59:59.000Z

    We investigate which shocked wind is responsible for the majority of the X-ray emission in colliding wind binaries, an issue where there is some confusion in the literature, and which we show is more complicated than has been assumed. We find that where both winds rapidly cool (typically close binaries), the ratio of the wind speeds is often more important than the momentum ratio, because it controls the energy flux ratio, and the faster wind is generally the dominant emitter. When both winds are largely adiabatic (typically long-period binaries), the slower and denser wind will cool faster and the stronger wind generally dominates the X-ray luminosity.

  7. Light and Life: Exotic Photosynthesis in Binary Star Systems

    E-Print Network [OSTI]

    O'Malley-James, J T; Cockell, C S; Greaves, J S

    2011-01-01T23:59:59.000Z

    The potential for hosting photosynthetic life on Earth-like planets within binary/multiple stellar systems was evaluated by modelling the levels of photosynthetically active radiation (PAR) such planets receive. Combinations of M and G stars in: (i) close-binary systems; (ii) wide-binary systems and (iii) three-star systems were investigated and a range of stable radiation environments found to be possible. These environmental conditions allow for the possibility of familiar, but also more exotic forms of photosynthetic life, such as infrared photosynthesisers and organisms specialised for specific spectral niches.

  8. The Binary Zoo: The Calculation of Production Rates of Binaries Through 2+1 Encounters in Globular Clusters

    E-Print Network [OSTI]

    M. B. Davies

    1995-07-07T23:59:59.000Z

    In studying encounters between binaries and single stars, one is interested in three classes of events: exchanges of stars, hardening of the original binary by a third star, and the production of merged objects. We present a means for computing cross sections for these three outcomes for an arbitrary binary and single star as might be found in the core of a globular cluster. The cross sections for a number of binaries in various stellar populations are then computed. We consider multiple encounters and the ultimate fate of a population of binaries fed into the cores of different globular cluster models. We see that the presence of only a relatively small number of binaries (containing 10\\% of the stars) will boost the production rate of astrophysically-interesting objects by a factor of at least a few over the rates expected from encounters between single stars. In particular, the ratio of smothered neutron stars to low-mass X-ray binaries (LMXBs) may be greatly increased, possibly explaining, in part, the excess of millisecond pulsars compared to LMXBs.

  9. Green's functions and hydrodynamics for isotopic binary diffusion

    E-Print Network [OSTI]

    R. van Zon; E. G. D. Cohen

    2005-08-10T23:59:59.000Z

    We study classical binary fluid mixtures in which densities vary on very short time (ps) and length (nm) scales, such that hydrodynamics does not apply. In a pure fluid with a localized heat pulse the breakdown of hydrodynamics was overcome using Green's functions which connect the initial densities to those at later times. Numerically it appeared that for long times the results from the Green's functions would approach hydrodynamics. In this paper we extend the Green's functions theory to binary mixtures. For the case of isothermal isobaric mutual diffusion in isotopic binary mixtures and ideal binary mixtures, which is easier to handle than heat conduction yet still non-trivial, we show analytically that in the Green's function approach one recovers hydrodynamic behaviour at long time scales provided the system reaches local equilibrium at long times. This is a first step toward giving the Green's function theory a firmer basis because it can for this case be considered as an extension of hydrodynamics.

  10. High energy gamma-rays from massive binary systems

    E-Print Network [OSTI]

    W. Bednarek

    2008-06-27T23:59:59.000Z

    During last years a few massive binary systems have been detected in the TeV gamma-rays. This gamma-ray emission is clearly modulated with the orbital periods of these binaries suggesting its origin inside the binary system. In this paper we summarize the anisotropic IC e-p pair cascade model as likely explanation of these observations. We consider scenarios in which particles are accelerated to relativistic energies, either due to the presence of an energetic pulsar inside the binary, or as a result of accretion process onto the compact object during which the jet is launched from the inner part of the accretion disk, or in collisions of stellar winds from the massive companions.

  11. accuracy binary black: Topics by E-print Network

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

    P. Uttley 2005-08-02 354 Black-Box Identification for PLC based MPC of a Binary Distillation Column Engineering Websites Summary: Black-Box Identification for PLC based MPC of...

  12. SOLIDIFICATION FRONTS AND SOLUTE TRAPPING IN A BINARY ALLOY

    E-Print Network [OSTI]

    Fife, Paul

    , Israel and PAUL C. FIFE , Mathematics Department, University of Utah, Salt Lake City, Utah 84112, USA9703483. 1 #12;1 Introduction During the process of solidification of molten binary alloys

  13. Grain boundary segregation and thermodynamically stable binary nanocrystalline alloys

    E-Print Network [OSTI]

    Trelewicz, Jason R.

    A free-energy function for binary polycrystalline solid solutions is developed based on pairwise nearest-neighbor interactions. The model permits intergranular regions to exhibit unique energetics and compositions from ...

  14. Synthesis and characterization of nanocrystalline binary and ternary intermetallic compounds

    E-Print Network [OSTI]

    Leonard, Brian Matthew

    2009-05-15T23:59:59.000Z

    -technological applications has generated renewed interest in their synthesis. Current capabilities for synthesizing nanocrystalline materials are well-established for single metals and simple binary phases, but very few processes are capable of reliably producing...

  15. Optimization With Parity Constraints: From Binary Codes to Discrete Integration

    E-Print Network [OSTI]

    Bejerano, Gill

    Optimization With Parity Constraints: From Binary Codes to Discrete Integration Stefano Ermon guarantees on the quality of the solution found. Markov Chain Monte Carlo [17, 21, 32] and Importance

  16. A class of non-binary LDPC codes

    E-Print Network [OSTI]

    Gilra, Deepak

    2004-09-30T23:59:59.000Z

    A CLASS OF NON-BINARY LDPC CODES A Thesis by DEEPAK GILRA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 2003 Major Subject: Electrical Engineering A CLASS OF NON-BINARY LDPC CODES A Thesis by DEEPAK GILRA Submitted to Texas A&M University in partial fulfillment of the requirements...

  17. Manifold corrections on spinning compact binaries

    SciTech Connect (OSTI)

    Zhong Shuangying; Wu Xin [Nanchang University, Nanchang 330031 (China)

    2010-05-15T23:59:59.000Z

    This paper deals mainly with a discussion of three new manifold correction methods and three existing ones, which can numerically preserve or correct all integrals in the conservative post-Newtonian Hamiltonian formulation of spinning compact binaries. Two of them are listed here. One is a new momentum-position scaling scheme for complete consistency of both the total energy and the magnitude of the total angular momentum, and the other is the Nacozy's approach with least-squares correction of the four integrals including the total energy and the total angular momentum vector. The post-Newtonian contributions, the spin effects, and the classification of orbits play an important role in the effectiveness of these six manifold corrections. They are all nearly equivalent to correct the integrals at the level of the machine epsilon for the pure Kepler problem. Once the third-order post-Newtonian contributions are added to the pure orbital part, three of these corrections have only minor effects on controlling the errors of these integrals. When the spin effects are also included, the effectiveness of the Nacozy's approach becomes further weakened, and even gets useless for the chaotic case. In all cases tested, the new momentum-position scaling scheme always shows the optimal performance. It requires a little but not much expensive additional computational cost when the spin effects exist and several time-saving techniques are used. As an interesting case, the efficiency of the correction to chaotic eccentric orbits is generally better than one to quasicircular regular orbits. Besides this, the corrected fast Lyapunov indicators and Lyapunov exponents of chaotic eccentric orbits are large as compared with the uncorrected counterparts. The amplification is a true expression of the original dynamical behavior. With the aid of both the manifold correction added to a certain low-order integration algorithm as a fast and high-precision device and the fast Lyapunov indicators of two nearby trajectories, phase space scans for chaos in the spinning compact binary system are given.

  18. Reliability Standards Owner

    Broader source: Energy.gov [DOE]

    This position is located in the Internal Operations and Asset Management group of Planning and Asset Management (TP). A successful candidate in this position will serve as the Reliability Standards...

  19. Microlensing Binaries Discovered through High-Magnification Channel

    E-Print Network [OSTI]

    Shin, I -G; Park, S -Y; Han, C; Allen, W; Bos, M; Christie, G W; Depoy, D L; Dong, S; Drummond, J; Gal-Yam, A; Gaudi, B S; Gould, A; Hung, L -W; Janczak, J; Kaspi, S; Lee, C -U; Mallia, F; Maoz, D; Maury, A; McCormick, J; Monard, L A G; Moorhouse, D; Munoz, J A; Natusch, T; Nelson, C; Park, B -G; Pogge, R W; Polishook, D; Shvartzvald, Y; Shporer, A; Thornley, G; Yee, J C; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Fukui, A; Furusawa, K; Hayashi, F; Hearnshaw, J B; Hosaka, S; Itow, Y; Kamiya, K; Kilmartin, P M; Kobara, S; Korpela, A; Lin, W; Ling, C H; Makita, S; Masuda, K; Matsubara, Y; Miyake, N; Muraki, Y; Nagaya, M; Nishimoto, K; Ohnishi, K; Okumura, T; Omori, K; Perrott, Y C; Rattenbury, N; Saito, To; Skuljan, L; Sullivan, D J; Sumi, T; Suzuki, D; Sweatman, W L; Tristram, P J; Wada, K; Yock, P C M; Szymanski, M K; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Udalski, A; Ulaczyk, K; Wyrzykowski, L; Albrow, M D; Batista, V; Beaulieu, J -P; Brillant, S; Cassan, A; Cole, A; Corrales, E; Coutures, Ch; Dieters, S; Prester, D Dominis; Donatowicz, J; Fouque, P; Greenhill, J; Kane, S R; Menzies, J; Sahu, K C; Wambsganss, J; Williams, A; Zub, M; Allan, A; Bramich, D M; Browne, P; Dominik, M; Horne, K; Kains, N; Snodgrass, C; Steele, I; Street, R; Tsapras, Y; Bozza, V; Burgdorf, M J; Novati, S Calchi; Dreizler, S; Finet, F; Glitrup, M; Grundahl, F; Harpsoe, K; Hinse, T C; Hundertmark, M; Jorgensen, U G; Liebig, C; Maier, G; Mancini, L; Mathiasen, M; Rahvar, S; Ricci, D; Scarpetta, G; Skottfelt, J; Surdej, J; Southworth, J; Zimmer, F

    2011-01-01T23:59:59.000Z

    Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of 8 binary lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3 \\sigma confidence level for 3 events, implying that the degeneracy would be an important obstacle in studying binary distributions. From investigating the dependence of the degeneracy on the lensing parameters, we find that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q~0.1, making the companion of the lens a strong brown-dwarf candidate.

  20. THE CLOSE BINARY FRACTION OF DWARF M STARS

    SciTech Connect (OSTI)

    Clark, Benjamin M. [Penn Manor High School, 100 East Cottage Avenue, Millersville, PA 17551 (United States); Blake, Cullen H.; Knapp, Gillian R. [Princeton University, Department of Astrophysical Sciences, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)

    2012-01-10T23:59:59.000Z

    We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template-fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs. Typically, the three or four spectra observed for each star are separated in time by less than four hours, but for {approx}17% of the stars, the individual observations span more than two days. In these cases we are sensitive to large-amplitude radial velocity variations on timescales comparable to the separation between the observations. We use a control sample of objects having observations taken within a four-hour period to make an empirical estimate of the underlying radial velocity error distribution and simulate our detection efficiency for a wide range of binary star systems. We find the frequency of binaries among the dwarf M stars with a < 0.4 AU to be 3%-4%. Comparison with other samples of binary stars demonstrates that the close binary fraction, like the total binary fraction, is an increasing function of primary mass.

  1. DIRECT N-BODY MODELING OF THE OLD OPEN CLUSTER NGC 188: A DETAILED COMPARISON OF THEORETICAL AND OBSERVED BINARY STAR AND BLUE STRAGGLER POPULATIONS

    SciTech Connect (OSTI)

    Geller, Aaron M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Hurley, Jarrod R. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia); Mathieu, Robert D., E-mail: a-geller@northwestern.edu, E-mail: mathieu@astro.wisc.edu, E-mail: jhurley@astro.swin.edu.au [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-01-01T23:59:59.000Z

    Following on from a recently completed radial-velocity survey of the old (7 Gyr) open cluster NGC 188 in which we studied in detail the solar-type hard binaries and blue stragglers of the cluster, here we investigate the dynamical evolution of NGC 188 through a sophisticated N-body model. Importantly, we employ the observed binary properties of the young (180 Myr) open cluster M35, where possible, to guide our choices for parameters of the initial binary population. We apply pre-main-sequence tidal circularization and a substantial increase to the main-sequence tidal circularization rate, both of which are necessary to match the observed tidal circularization periods in the literature, including that of NGC 188. At 7 Gyr the main-sequence solar-type hard-binary population in the model matches that of NGC 188 in both binary frequency and distributions of orbital parameters. This agreement between the model and observations is in a large part due to the similarities between the NGC 188 and M35 solar-type binaries. Indeed, among the 7 Gyr main-sequence binaries in the model, only those with P {approx}> 1000 days begin to show potentially observable evidence for modifications by dynamical encounters, even after 7 Gyr of evolution within the star cluster. This emphasizes the importance of defining accurate initial conditions for star cluster models, which we propose is best accomplished through comparisons with observations of young open clusters like M35. Furthermore, this finding suggests that observations of the present-day binaries in even old open clusters can provide valuable information on their primordial binary populations. However, despite the model's success at matching the observed solar-type main-sequence population, the model underproduces blue stragglers and produces an overabundance of long-period circular main-sequence-white-dwarf binaries as compared with the true cluster. We explore several potential solutions to the paucity of blue stragglers and conclude that the model dramatically underproduces blue stragglers through mass-transfer processes. We suggest that common-envelope evolution may have been incorrectly imposed on the progenitors of the spurious long-period circular main-sequence-white-dwarf binaries, which perhaps instead should have gone through stable mass transfer to create blue stragglers, thereby bringing both the number and binary frequency of the blue straggler population in the model into agreement with the true blue stragglers in NGC 188. Thus, improvements in the physics of mass transfer and common-envelope evolution employed in the model may in fact solve both discrepancies with the observations. This project highlights the unique accessibility of open clusters to both comprehensive observational surveys and full-scale N-body simulations, both of which have only recently matured sufficiently to enable such a project, and underscores the importance of open clusters to the study of star cluster dynamics.

  2. Mesoscale solubilization and critical phenomena in binary and quasi binary solutions of hydrotropes

    E-Print Network [OSTI]

    Andreas E. Robertson; Dung H. Phan; Joseph E. Macaluso; Vladimir N. Kuryakov; Elena V. Jouravleva; Christopher E. Bertrand; Igor K. Yudin; Mikhail A. Anisimov

    2015-03-24T23:59:59.000Z

    Hydrotropes are substances consisting of amphiphilic molecules that are too small to self assemble in equilibrium structures in aqueous solutions, but can form dynamic molecular clusters H bonded with water molecules. Some hydrotropes, such as low molecular weight alcohols and amines, can solubilize hydrophobic compounds in aqueous solutions at a mesoscopic scale, around 100 nm, with formation of long lived mesoscale droplets. In this work, we report on the studies of near critical and phase behavior of binary, 2,6-lutidine - H2O, and quasibinary, 2,6-lutidine - H2O - D2O, and tert-butanol - 2-butanol - H2O solutions in the presence of a solubilized hydrophobic impurity, cyclohexane. In additional to visual observation of fluid phase equilibria, two experimental techniques were used - light scattering and small - angle neutron scattering. It was found that the increase of the tert-butanol to 2-butanol ratio affects the liquid - liquid equilibria in the quasi-binary system at ambient pressure in the same way as the increase of pressure modifies the phase behavior of binary 2-butanol - H2O solutions. The correlation length of critical fluctuations near the liquid-liquid separation and the size of mesoscale droplets of solubilized cyclohexane were obtained by dynamic light scattering and by small - angle neutron scattering. It is shown that the effect of the presence of small amounts of cyclohexane on the near - critical phase behavior is twofold - the transition temperature changes towards increasing the two-phase domain, and long-lived mesoscopic inhomogeneities emerge in the macroscopically homogeneous domain. These homogeneities remain unchanged upon approach to the critical point of macroscopic phase separation and do not alter the universal nature of criticality. However, a larger amount of cyclohexane generates additional liquid-liquid phase separation at lower temperatures.

  3. TYPE OF OPERATION

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3uj: ;;I :NAME: fOwner c:ontacted

  4. TYPE OF OPERATION

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3uj: ;;I :NAME: fOwner

  5. TYPE OF OPERATION

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3uj: ;;I :NAME: fOwner______ 0

  6. TYPE OF OPERATION

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3uj: ;;I :NAME: fOwner______

  7. Phase Transformations in Binary Colloidal Monolayers

    E-Print Network [OSTI]

    Ye Yang; Lin Fu; Catherine Marcoux; Joshua E. S. Socolar; Patrick Charbonneau; Benjamin B. Yellen

    2015-02-10T23:59:59.000Z

    Phase transformations can be difficult to characterize at the microscopic level due to the inability to directly observe individual atomic motions. Model colloidal systems, by contrast, permit the direct observation of individual particle dynamics and of collective rearrangements, which allows for real-space characterization of phase transitions. Here, we study a quasi-two-dimensional, binary colloidal alloy that exhibits liquid-solid and solid-solid phase transitions, focusing on the kinetics of a diffusionless transformation between two crystal phases. Experiments are conducted on a monolayer of magnetic and nonmagnetic spheres suspended in a thin layer of ferrofluid and exposed to a tunable magnetic field. A theoretical model of hard spheres with point dipoles at their centers is used to guide the choice of experimental parameters and characterize the underlying materials physics. When the applied field is normal to the fluid layer, a checkerboard crystal forms; when the angle between the field and the normal is sufficiently large, a striped crystal assembles. As the field is slowly tilted away from the normal, we find that the transformation pathway between the two phases depends strongly on crystal orientation, field strength, and degree of confinement of the monolayer. In some cases, the pathway occurs by smooth magnetostrictive shear, while in others it involves the sudden formation of martensitic plates.

  8. Diffusion and Interdiffusion in Binary Metallic Melts

    E-Print Network [OSTI]

    P. Kuhn; J. Horbach; F. Kargl; A. Meyer; Th. Voigtmann

    2014-08-09T23:59:59.000Z

    We discuss the dependence of self- and interdiffusion coefficients on temperature and composition for two prototypical binary metallic melts, Al-Ni and Zr-Ni, in molecular-dynamics (MD) computer simulations and the mode-coupling theory of the glass transition (MCT). Dynamical processes that are mainly entropic in origin slow down mass transport (as expressed through self diffusion) in the mixture as compared to the ideal-mixing contribution. Interdiffusion of chemical species is a competition of slow kinetic modes with a strong thermodynamic driving force that is caused by non-entropic interactions. The combination of both dynamic and thermodynamic effects causes qualitative differences in the concentration dependence of self-diffusion and interdiffusion coefficients. At high temperatures, the thermodynamic enhancement of interdiffusion prevails, while at low temperatures, kinetic effects dominate the concentration dependence, rationalized within MCT as the approach to its ideal-glass transition temperature $T_c$. The Darken equation relating self- and interdiffusion qualitatively reproduces the concentration-dependence in both Zr-Ni and Al-Ni, but quantitatively, the kinetic contributions to interdiffusion can be slower than the lower bound suggested by the Darken equation. As temperature is decreased, the agreement with Darken's equation improves, due to a strong coupling of all kinetic modes that is a generic feature predicted by MCT.

  9. Structural and dynamical properties of a quasi-one-dimensional classical binary system

    E-Print Network [OSTI]

    W. P. Ferreira; J. C. N. Carvalho; P. W. S. Oliveira; G. A. Farias; F. M. Peeters

    2010-06-09T23:59:59.000Z

    The ground state configurations and the \\lq{}\\lq{}normal\\rq{}\\rq{} mode spectra of a $quasi$-one-dimensional (Q1D) binary system of charged particles interacting through a screened Coulomb potential are presented. The minimum energy configurations were obtained analytically and independently through molecular dynamic simulations. A rich variety of ordered structures were found as a function of the screening parameter, the particle density, and the ratio between the charges of the distinct types of particles. Continuous and discontinuous structural transitions, as well as an unexpected symmetry breaking in the charge distribution are observed when the density of the system is changed. For near equal charges we found a disordered phase where a mixing of the two types of particles occurs. The phonon dispersion curves were calculated within the harmonic approximation for the one- and two-chain structures.

  10. Comparing the precision 2009 and 2012 light curves of the precontact W UMa binary V1001 Cassiopeia

    SciTech Connect (OSTI)

    Samec, R. G. [Faculty Research Affiliate, Pisgah Astronomical Research Institute, One Pari Drive, Rosman, NC 28772 (United States); Koenke, S. S. [Physics and Engineering Dept., Bob Jones University, 1700 Wade Hampton Boulevard, Greenville, SC 29614 (United States); Faulkner, D. R. [University of South Carolina Lancaster, 476 Hubbard Drive, Lancaster SC 29720 (United States)

    2015-01-01T23:59:59.000Z

    A 2012 follow up to the analysis of 2009 observations is presented for the very short period (?0.43 days) precontact W UMa binary (PCWB) V1001 Cassiopeia. Its short period, similar to the majority of W UMa binaries, and its distinct EA light curve make it a very rare and interesting system for continuing photometric investigation. Previous photometric VRI standard magnitudes give a K4 spectral type. Our solutions of light curves separated by some three years give approximately the same physical parameters. However, the spots have radically changed in temperature, area, and position. While only one dark spot was used to model the first curves, two hot spots are now needed. This affects the overall shape of the light curve, especially in the secondary eclipses in B and V. Additional eclipse timings now show that the orbital period is changing. We conclude that spots are very active on this solar-type dwarf system and that it may mimic its larger cousins, the RS CVn binaries. The conclusion is that analysis now needs to be directed at the continuous time evolution of PCWBs.

  11. Molecular Design of Branched and Binary Molecules at Ordered Interfaces

    SciTech Connect (OSTI)

    Kirsten Larson Genson

    2005-12-27T23:59:59.000Z

    This study examined five different branched molecular architectures to discern the effect of design on the ability of molecules to form ordered structures at interfaces. Photochromic monodendrons formed kinked packing structures at the air-water interface due to the cross-sectional area mismatch created by varying number of alkyl tails and the hydrophilic polar head group. The lower generations formed orthorhombic unit cell with long range ordering despite the alkyl tails tilted to a large degree. Favorable interactions between liquid crystalline terminal groups and the underlying substrate were observed to compel a flexible carbosilane dendrimer core to form a compressed elliptical conformation which packed stagger within lamellae domains with limited short range ordering. A twelve arm binary star polymer was observed to form two dimensional micelles at the air-water interface attributed to the higher polystyrene block composition. Linear rod-coil molecules formed a multitude of packing structures at the air-water interface due to the varying composition. Tree-like rod-coil molecules demonstrated the ability to form one-dimensional structures at the air-water interface and at the air-solvent interface caused by the preferential ordering of the rigid rod cores. The role of molecular architecture and composition was examined and the influence chemically competing fragments was shown to exert on the packing structure. The amphiphilic balance of the different molecular series exhibited control on the ordering behavior at the air-water interface and within bulk structures. The shell nature and tail type was determined to dictate the preferential ordering structure and molecular reorganization at interfaces with the core nature effect secondary.

  12. The Connection Between Low-Mass X-ray Binaries and (Millisecond) Pulsars: A Binary Evolution Perspective

    E-Print Network [OSTI]

    Christopher J. Deloye

    2007-10-01T23:59:59.000Z

    I review the evolutionary connection between low-mass X-ray binaries (LMXBs) and pulsars with binary companions (bPSRs) from a stellar binary evolution perspective. I focus on the evolution of stellar binaries with end-states consisting of a pulsar with a low-mass (<1.0 solar mass) companion, starting at the point the companion's progenitor first initiates mass transfer onto the neutron star. Whether this mass transfer is stable and the physics driving ongoing mass transfer partitions the phase space of the companions's initial mass and initial orbital period into five regions. The qualitative nature of the mass-transfer process and the binary's final end-state differ between systems in each region; four of these regions each produce a particular class of LMXBs. I compare the theoretical expectations to the populations of galactic field LMXBs with companion-mass constraints and field bPSRs. I show that the population of accreting millisecond pulsars are all identified with only two of the four LMXB classes and that these systems do not have readily identifiable progeny in the bPSR population. I discuss which sub-populations of bPSRs can be explained by binary evolution theory and those that currently are not. Finally I discuss some outstanding questions in this field.

  13. The Secondary Star in Cataclysmic Variables and Low Mass X-ray Binaries

    E-Print Network [OSTI]

    D. A. Smith; V. S. Dhillon

    1998-08-20T23:59:59.000Z

    We critically re-examine the available data on the spectral types, masses and radii of the secondary stars in cataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs), using the new catalogue of Ritter & Kolb (1998) as a starting point. We find there are 55 reliable spectral type determinations and only 14 reliable mass determinations of CV secondary stars (10 and 5, respectively, in the case of LMXBs). We derive new spectral type-period, mass-radius, mass-period and radius-period relations, and compare them with theoretical predictions. We find that CV secondary stars with orbital periods shorter than 7-8 hours are, as a group, indistinguishable from main sequence stars in detached binaries. We find it is not valid, however, to estimate the mass from the spectral type of the secondary star in CVs or LMXBs. We find that LMXB secondary stars show some evidence for evolution, with secondary stars which are slightly too large for their mass. We show how the masses and radii of the secondary stars in CVs can be used to test the validity of the disrupted magnetic braking model of CV evolution, but we find that the currently available data are not sufficiently accurate or numerous to allow such an analysis. As well as considering secondary star masses, we also discuss the masses of the white dwarfs in CVs, and find mean values of M_1 = 0.69+/-0.13 M_sun below the period gap, and M_1 = 0.80+/-0.22 M_sun above the period gap.

  14. Radial Velocity Studies of Close Binary Stars. XI

    E-Print Network [OSTI]

    Theodor Pribulla; Slavek M. Rucinski; Wenxian Lu; Stefan W. Mochnacki; George Conidis; R. M. Blake; Heide DeBond; J. R. Thomson; Wojtek Pych; Waldemar Ogloza; Michal Siwak

    2006-05-15T23:59:59.000Z

    Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for ten close binary systems: DU Boo, ET Boo, TX Cnc, V1073 Cyg, HL Dra, AK Her, VW LMi, V566 Oph, TV UMi and AG Vir. By this contribution, the DDO program has reached the point of 100 published radial velocity orbits. The radial velocities have been determined using an improved fitting technique which uses rotational profiles to approximate individual peaks in broadening functions. Three systems, ET Boo, VW LMi and TV UMi, were found to be quadruple while AG Vir appears to be a spectroscopic triple. ET Boo, a member of a close visual binary with $P_{vis} = 113$ years, was previously known to be a multiple system, but we show that the second component is actually a close, non-eclipsing binary. The new observations enabled us to determine the spectroscopic orbits of the companion, non-eclipsing pairs in ET Boo and VW LMi. The particularly interesting case is VW LMi, where the period of the mutual revolution of the two spectroscopic binaries is only 355 days. While most of the studied eclipsing pairs are contact binaries, ET Boo is composed of two double-lined detached binaries and HL Dra is single-lined detached or semi-detached system. Five systems of this group were observed spectroscopically before: TX Cnc, V1073 Cyg, AK Her (as a single-lined binary), V566 Oph, AG Vir, but our new data are of much higher quality than the previous studies.

  15. The youngest known X-ray binary: Circinus X-1 and its natal supernova remnant

    SciTech Connect (OSTI)

    Heinz, S.; Sell, P. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Fender, R. P. [Sub-department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Jonker, P. G. [SRON, Netherlands Institute for Space Research, 3584-CA, Utrecht (Netherlands); Brandt, W. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Calvelo-Santos, D. E. [Department of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Tzioumis, A. K. [Australia Telescope National Facility, CSIRO, Epping, NSW 1710 (Australia); Nowak, M. A.; Schulz, N. S. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Wijnands, R.; Van der Klis, M., E-mail: heinzs@astro.wisc.edu [Astronomical Institute "Anton Pannekoek," University of Amsterdam, 1090-GE Amsterdam (Netherlands)

    2013-12-20T23:59:59.000Z

    Because supernova remnants are short-lived, studies of neutron star X-ray binaries within supernova remnants probe the earliest stages in the life of accreting neutron stars. However, such objects are exceedingly rare: none were known to exist in our Galaxy. We report the discovery of the natal supernova remnant of the accreting neutron star Circinus X-1, which places an upper limit of t < 4600 yr on its age, making it the youngest known X-ray binary and a unique tool to study accretion, neutron star evolution, and core-collapse supernovae. This discovery is based on a deep 2009 Chandra X-ray observation and new radio observations of Circinus X-1. Circinus X-1 produces type I X-ray bursts on the surface of the neutron star, indicating that the magnetic field of the neutron star is small. Thus, the young age implies either that neutron stars can be born with low magnetic fields or that they can rapidly become de-magnetized by accretion. Circinus X-1 is a microquasar, creating relativistic jets that were thought to power the arcminute-scale radio nebula surrounding the source. Instead, this nebula can now be attributed to non-thermal synchrotron emission from the forward shock of the supernova remnant. The young age is consistent with the observed rapid orbital evolution and the highly eccentric orbit of the system and offers the chance to test the physics of post-supernova orbital evolution in X-ray binaries in detail for the first time.

  16. Constraining the mass transfer in massive binaries through progenitor evolution models of Wolf-Rayet+O binaries

    E-Print Network [OSTI]

    Jelena Petrovic; Norbert Langer; Karel A. van der hucht

    2005-04-11T23:59:59.000Z

    Since close WR+O binaries are the result of a strong interaction of both stars in massive close binary systems, they can be used to constrain the highly uncertain mass and angular momentum budget during the major mass transfer phase. We explore the progenitor evolution of the three best suited WR+O binaries HD 90657, HD 186943 and HD 211853, which are characterized by a WR/O mass ratio of $\\sim$0.5 and periods of 6..10 days. We are doing so at three different levels of approximation: predicting the massive binary evolution through simple mass loss and angular momentum loss estimates, through full binary evolution models with parametrized mass transfer efficiency, and through binary evolution models including rotation of both components and a physical model which allows to compute mass and angular momentum loss from the binary system as function of time during the mass transfer process. All three methods give consistently the same answers. Our results show that, if these systems formed through stable mass transfer, their initial periods were smaller than their current ones, which implies that mass transfer has started during the core hydrogen burning phase of the initially more massive star. Furthermore, the mass transfer in all three cases must have been highly non-conservative, with on average only $\\sim$10% of the transferred mass being retained by the mass receiving star. This result gives support to our system mass and angular momentum loss model, which predicts that, in the considered systems, about 90% of the overflowing matter is expelled by the rapid rotation of the mass receiver close to the $\\Omega$-limit, which is reached through the accretion of the remaining 10%.

  17. Mergers of binary neutron stars with realistic spin

    E-Print Network [OSTI]

    Sebastiano Bernuzzi; Tim Dietrich; Wolfgang Tichy; Bernd Bruegmann

    2014-06-06T23:59:59.000Z

    Simulations of binary neutron stars have seen great advances in terms of physical detail and numerical quality. However, the spin of the neutron stars, one of the simplest global parameters of binaries, remains mostly unstudied. We present the first, fully nonlinear general relativistic dynamical evolutions of the last three orbits for constraint satisfying initial data of spinning neutron star binaries, with astrophysically realistic spins aligned and anti-aligned to the orbital angular momentum. The initial data is computed with the constant rotational velocity approach. The dynamics of the systems is analyzed in terms of gauge-invariant binding energy vs. orbital angular momentum curves. By comparing to a binary black hole configuration we can estimate the different tidal and spin contributions to the binding energy for the first time. First results on the gravitational wave forms are presented. The phase evolution during the orbital motion is significantly affected by spin-orbit interactions, leading to delayed or early mergers. Furthermore, a frequency shift in the main emission mode of the hyper massive neutron star is observed. Our results suggest that a detailed modeling of merger waveforms requires the inclusion of spin, even for the moderate magnitudes observed in binary neutron star systems.

  18. The DWARF project: Eclipsing binaries - precise clocks to discover exoplanets

    E-Print Network [OSTI]

    Pribulla, T; von Eiff, M Ammler -; Andreev, M; Aslant黵k, A; Awadalla, N; Balu?ansk, D; Bonanno, A; Bo瀒?, H; Catanzaro, G; 莈lik, L; Christopoulou, P E; Covino, E; Cusano, F; Dimitrov, D; Dubovsk, P; Esmer, E M; Frasca, A; Hamb醠ek, ?; Hanna, M; Hanslmeier, A; Kalomeni, B; Kjurkchieva, D P; Krushevska, V; Kudzej, I; Kundra, E; Kuznyetsova, Yu; Lee, J W; Leitzinger, M; Maciejewski, G; Moldovan, D; Morais, M H M; Mugrauer, M; Neuh鋟ser, R; Niedzielski, A; Odert, P; Ohlert, J; 謟avc?, ?; Papageorgiou, A; Parimucha, ; Poddan, S; Pop, A; Raetz, M; Raetz, S; Romanyuk, Ya; Ru瀌jak, D; Schulz, J; ?enavc?, H V; Szalai, T; Sz閗ely, P; Sudar, D; Tezcan, C T; T鰎黱, M E; Turcu, V; Vince, O; Zejda, M

    2012-01-01T23:59:59.000Z

    We present a new observational campaign, DWARF, aimed at detection of circumbinary extrasolar planets using the timing of the minima of low-mass eclipsing binaries. The observations will be performed within an extensive network of relatively small to medium-size telescopes with apertures of ~20-200 cm. The starting sample of the objects to be monitored contains (i) low-mass eclipsing binaries with M and K components, (ii) short-period binaries with sdB or sdO component, and (iii) post-common-envelope systems containing a WD, which enable to determine minima with high precision. Since the amplitude of the timing signal increases with the orbital period of an invisible third component, the timescale of project is long, at least 5-10 years. The paper gives simple formulas to estimate suitability of individual eclipsing binaries for the circumbinary planet detection. Intrinsic variability of the binaries (photospheric spots, flares, pulsation etc.) limiting the accuracy of the minima timing is also discussed. The...

  19. Dynamical resonance locking in tidally interacting binary systems

    E-Print Network [OSTI]

    Joshua Burkart; Eliot Quataert; Phil Arras

    2014-10-25T23:59:59.000Z

    We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin and orbital frequencies vary in concert to maintain the resonance. This phenomenon is qualitatively similar to resonance capture in planetary dynamics. We show that resonance locks can accelerate the course of tidal evolution in eccentric systems and also efficiently couple spin and orbital evolution in circular binaries. Previous analyses of resonance locking have not treated the mode amplitude as a fully dynamical variable, but rather assumed the adiabatic (i.e. Lorentzian) approximation valid only in the limit of relatively strong mode damping. We relax this approximation, analytically derive conditions under which the fixed point associated with resonance locking is stable, and further check these analytic results using numerical integrations of the coupled mode, spin, and orbital evolution equations. These show that resonance locking can sometimes take the form of complex limit cycles or even chaotic trajectories. We provide simple analytic formulae that define the binary and mode parameter regimes in which resonance locks of some kind occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical implications of our results for white dwarf and neutron star binaries as well as eccentric stellar binaries.

  20. The Ratio of Retrograde to Prograde Orbits: A Test for Kuiper Belt Binary Formation Theories

    E-Print Network [OSTI]

    Hilke E. Schlichting; Re'em Sari

    2008-07-03T23:59:59.000Z

    With the discovery of Kuiper Belt binaries that have wide separations and roughly equal masses new theories were proposed to explain their formation. Two formation scenarios were suggested by Goldreich and collaborators: In the first, dynamical friction that is generated by a sea of small bodies enables a transient binary to become bound ($L^2s$ mechanism); in the second, a transient binary gets bound by an encounter with a third body ($L^3$ mechanism). We show that these different binary formation scenarios leave their own unique signatures in the relative abundance of prograde to retrograde binary orbits. This signature is due to stable retrograde orbits that exist much further out in the Hill sphere than prograde orbits. It provides an excellent opportunity to distinguish between the different binary formation scenarios observationally. We predict that if binary formation proceeded while sub-Hill velocities prevailed, the vast majority of all comparable mass ratio binaries have retrograde orbits. This dominance of retrograde binary orbits is a result of binary formation via the $L^2s$ mechanism, or any other mechanism that dissipates energy in a smooth and gradual manner. For super-Hill velocities binary formation proceeds via the $L^3$ mechanism which produces a roughly equal number of prograde and retrograde binaries. These predictions assume that subsequent orbital evolution due to dynamical friction and dynamical stirring of the Kuiper belt did not alter the sense of the binary orbit after formation.

  1. Photometric study of the pulsating, eclipsing binary OO DRA

    SciTech Connect (OSTI)

    Zhang, X. B.; Deng, L. C.; Tian, J. F.; Wang, K.; Yan, Z. Z.; Luo, C. Q. [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Sun, J. J.; Liu, Q. L.; Xin, H. Q.; Zhou, Q. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Z. Q. [Department of Physics, China West Normal University, Nanchong 637002 (China)

    2014-12-01T23:59:59.000Z

    We present a comprehensive photometric study of the pulsating, eclipsing binary OO Dra. Simultaneous B- and V-band photometry of the star was carried out on 14 nights. A revised orbital period and a new ephemeris were derived from the data. The first photometric solution of the binary system and the physical parameters of the component stars are determined. They reveal that OO Dra could be a detached system with a less-massive secondary component nearly filling its Roche lobe. By subtracting the eclipsing light changes from the data, we obtained the intrinsic pulsating light curves of the hotter, massive primary component. A frequency analysis of the residual light yields two confident pulsation modes in both B- and V-band data with the dominant frequency detected at 41.865 c/d. A brief discussion concerning the evolutionary status and the pulsation nature of the binary system is finally given.

  2. V405 Peg (RBS 1955): A Nearby, Low-Luminosity Cataclysmic Binary

    E-Print Network [OSTI]

    Thorstensen, J R; Schwope, A D; Staude, A; Vogel, J; Krumpe, M; Kohnert, J; Gomez-Moran, A Nebot

    2009-01-01T23:59:59.000Z

    (Abridged). The cataclysmic binary V405 Peg, originally discovered as ROSAT Bright Source (RBS) 1955 (= 1RXS J230949.6+213523), shows a strong contribution from a late-type secondary star in its optical spectrum, which led Schwope et al. to suggest it to be among the nearest cataclysmic binaries. We present extensive optical observations of V405 Peg. Time-series spectroscopy shows the orbital period, Porb, to be 0.1776469(7) d (= 4.2635 hr), or 5.629 cycle/d. We classify the secondary as M3 - M4.5. Astrometry with the MDM 2.4m telescope gives a parallax 7.2 +- 1.1 milli-arcsec, and a relative proper motion of 58 mas/yr. Our best estimate of the distance yields d = 149 (+26, -20) pc. The secondary stars's radial velocity has K2 = 92 +- 3 km/s, indicating a fairly low orbital inclination if the masses are typical. Extensive I-band time-series observations in the show the system varying between a minimum brightness level of I = 14.14 and states of enhanced activity about 0.2 mag brighter. While the low-state sho...

  3. Photometric analysis of overcontact binaries AK Her, HI Dra, V1128 Tau and V2612 Oph

    E-Print Network [OSTI]

    Caliskan, S; Djurasevic, G; Ozavci, I; Basturk, O; Cseki, A; Senavci, H V; Kilicoglu, T; Yilmaz, M; Selam, S O

    2014-01-01T23:59:59.000Z

    We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau and V2612 Oph, and determine their orbital and physical parameters using the modeling program of G. Djurasevic and recently published results of radial velocity studies. The achieved precision in absolute masses is between 10 and 20%, and in absolute radii between 5 and 10%. All four systems are W UMa type binaries with bright or dark spots indicative of mass and energy transfer or surface activity. We estimate the distances and the ages of the systems using the luminosities computed through our analysis, and perform an O-C study for V1128 Tau, which reveals a complex period variation that can be interpreted in terms of mass loss/exchange and either the presence of the third body, or the magnetic activity on one of the components. We conclude that further observations of these systems are needed to deepen our understanding of their nature and variability.

  4. COMPACT BINARY PROGENITORS OF SHORT GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Giacomazzo, Bruno [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309 (United States); Perna, Rosalba [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Rezzolla, Luciano [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Potsdam D-14476 (Germany); Troja, Eleonora [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lazzati, Davide [Department of Physics, NC State University, 2401 Stinson Drive, Raleigh, NC 27695-8202 (United States)

    2013-01-10T23:59:59.000Z

    In recent years, detailed observations and accurate numerical simulations have provided support to the idea that mergers of compact binaries containing either two neutron stars (NSs) or an NS and a black hole (BH) may constitute the central engine of short gamma-ray bursts (SGRBs). The merger of such compact binaries is expected to lead to the production of a spinning BH surrounded by an accreting torus. Several mechanisms can extract energy from this system and power the SGRBs. Here we connect observations and numerical simulations of compact binary mergers, and use the current sample of SGRBs with measured energies to constrain the mass of their powering tori. By comparing the masses of the tori with the results of fully general-relativistic simulations, we are able to infer the properties of the binary progenitors that yield SGRBs. By assuming a constant efficiency in converting torus mass into jet energy, {epsilon}{sub jet} = 10%, we find that most of the tori have masses smaller than 0.01 M{sub Sun }, favoring 'high-mass' binary NSs mergers, i.e., binaries with total masses {approx}> 1.5 the maximum mass of an isolated NS. This has important consequences for the gravitational wave signals that may be detected in association with SGRBs, since 'high-mass' systems do not form a long-lived hypermassive NS after the merger. While NS-BH systems cannot be excluded to be the engine of at least some of the SGRBs, the BH would need to have an initial spin of {approx}0.9 or higher.

  5. Relaxation dynamics in a binary hard-ellipse liquid

    E-Print Network [OSTI]

    Wen-Sheng Xu; Zhao-Yan Sun; Li-Jia An

    2014-12-01T23:59:59.000Z

    Structural relaxation in binary hard spherical particles has been shown recently to exhibit a wealth of remarkable features when size disparity or mixture's composition is varied. In this paper, we test whether or not similar dynamical phenomena occur in glassy systems composed of binary hard ellipses. We demonstrate via event-driven molecular dynamics simulation that a binary hard-ellipse mixture with an aspect ratio of two and moderate size disparity displays characteristic glassy dynamics upon increasing density in both the translational and the rotational degrees of freedom. The rotational glass transition density is found to be close to the translational one for the binary mixtures investigated. More importantly, we assess the influence of size disparity and mixture's composition on the relaxation dynamics. We find that an increase of size disparity leads, both translationally and rotationally, to a speed up of the long-time dynamics in the supercooled regime so that both the translational and the rotational glass transition shift to higher densities. By increasing the number concentration of the small particles, the time evolution of both translational and rotational relaxation dynamics at high densities displays two qualitatively different scenarios, i.e., both the initial and the final part of the structural relaxation slow down for small size disparity, while the short-time dynamics still slows down but the final decay speeds up in the binary mixture with large size disparity. These findings are reminiscent of those observed in binary hard spherical particles. Therefore, our results suggest a universal mechanism for the influence of size disparity and mixture's composition on the structural relaxation in both isotropic and anisotropic particle systems.

  6. Radar Imaging and Characterization of Binary Near-Earth Asteroid (185851) 2000 DP107

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    modeling of triple near-Earth Asteroid (136617) 1994 CC.CHARACTERIZATION OF BINARY NEAR-EARTH ASTEROID (185851) 2000of Contact Binary Near-Earth Asteroids. In AAS/Division for

  7. 13 New Eclipsing Binaries with Additional Variability in the ASAS Catalogue

    E-Print Network [OSTI]

    B. Pilecki; D. M. Szczygie?

    2007-05-11T23:59:59.000Z

    We present 13 new ASAS eclipsing binaries that exhibit additional periodic variability due to pulsations, eclipses with another period or spots. All contact and semi-detached binaries from the ASAS Catalogue were investigated.

  8. Optical simulation of neutrino oscillations in binary waveguide arrays

    E-Print Network [OSTI]

    Marini, Andrea; Biancalana, Fabio

    2014-01-01T23:59:59.000Z

    We theoretically propose and investigate an optical analogue of neutrino oscillations in a pair of vertically displaced binary waveguide arrays with longitudinally modulated effective refractive index. Optical propagation is modelled through coupled-mode equations, which in the continuous limit lead to two coupled Dirac equations for fermionic particles with different mass states, i.e. neutrinos. We demonstrate that neutrino oscillations can be quenched by nonlinear effects, and we predict the existence of neutrino solitons. Incidentally, these phenomena are expected to play an important role in massive supernova stars. Our results pave the way for using binary waveguide arrays as a classical laboratory for predicting exotic effects in particle physics and astrophysics.

  9. Optical simulation of neutrino oscillations in binary waveguide arrays

    E-Print Network [OSTI]

    Andrea Marini; Stefano Longhi; Fabio Biancalana

    2014-05-06T23:59:59.000Z

    We theoretically propose and investigate an optical analogue of neutrino oscillations in a pair of vertically displaced binary waveguide arrays with longitudinally modulated effective refractive index. Optical propagation is modelled through coupled-mode equations, which in the continuous limit lead to two coupled Dirac equations for fermionic particles with different mass states, i.e. neutrinos. We demonstrate that neutrino oscillations can be quenched by nonlinear effects, and we predict the existence of neutrino solitons. Incidentally, these phenomena are expected to play an important role in massive supernova stars. Our results pave the way for using binary waveguide arrays as a classical laboratory for predicting exotic effects in particle physics and astrophysics.

  10. Some comments on the electrodynamics of binary pulsars

    E-Print Network [OSTI]

    Sobacchi, Emanuele

    2015-01-01T23:59:59.000Z

    We consider the electrodynamics of in-spiraling binary pulsars, showing that there are two distinct ways in which they may emit radiation. On the one hand, even if the pulsars do not rotate, we show that in vacuo orbital rotation generates magnetic quadrupole emission, which, in the late stages of the binary evolution becomes nearly as effective as magnetic dipole emission by a millisecond pulsar. On the other hand, we show that interactions of the two magnetic fields generate powerful induction electric fields, which cannot be screened by a suitable distribution of charges and currents like they are in isolated pulsars. We compute approximate electromotive forces for this case.

  11. High-resolution radio observations of X-ray binaries

    E-Print Network [OSTI]

    James Miller-Jones

    2008-09-15T23:59:59.000Z

    I present an overview of important results obtained using high-resolution very long baseline interferometry (VLBI) observations of X-ray binary systems. These results derive from both astrometric observations and resolved imaging of sources, from black holes to neutron star and even white dwarf systems. I outline a number of upcoming developments in instrumentation, both new facilities and ongoing upgrades to existing VLBI instruments, and I conclude by identifying a number of important areas of investigation where VLBI will be crucial in advancing our understanding of X-ray binaries.

  12. A radio-map of the colliding winds in the very massive binary system HD 93129A

    E-Print Network [OSTI]

    Benaglia, Paula; Moldon, Javier; Nelan, Ed; De Becker, Michael; Dougherty, Sean M; Koribalski, Baerbel

    2015-01-01T23:59:59.000Z

    Radio observations are an effective tool to discover particle acceleration regions in colliding-wind binaries, through detection of synchrotron radiation; these regions are natural laboratories for the study of relativistic particles. Wind-collision region (WCR) models can reproduce the radio continuum spectra of massive binaries that contain both thermal and non-thermal radio emission; however, key constraints for models come from high-resolution imaging. Only five WCRs have been resolved to date at radio frequencies at milliarcsec (mas) angular scales. The source HD 93129A, prototype of the very few known O2 I stars, is a promising target for study: recently, a second massive, early-type star about 50 mas away was discovered, and a non-thermal radio source detected in the region. Preliminary long-baseline array data suggest that a significant fraction of the radio emission from the system comes from a putative WCR. We sought evidence that HD 93129A is a massive binary system with colliding stellar winds tha...

  13. Symmetric chains, Gelfand-Tsetlin chains, and the Terwilliger algebra of the binary Hamming scheme

    E-Print Network [OSTI]

    Srinivasan, Murali K.

    Symmetric chains, Gelfand-Tsetlin chains, and the Terwilliger algebra of the binary Hamming scheme of the Terwilliger algebra of the binary Hamming scheme. We also give a representation theoretic characterization constructive proof of the explicit block diagonalization of the Terwilliger algebra of the binary Hamming

  14. Liquid-solid phase diagrams of binary carbonates for lithium batteries

    SciTech Connect (OSTI)

    Ding, M.S.; Xu, K.; Jow, T.R.

    2000-05-01T23:59:59.000Z

    The authors present the liquid-solid phase diagrams that they mapped with a differential scanning calorimeter (DSC) for the following seven binary carbonates: dimethyl carbonate (DMC)-ethylene carbonate (EC), ethyl methyl carbonate (EMC)-EC, EMC-propylene carbonate (PC), EMC-dimethyl ethylene carbonate (DMEC), EMC-isobutylene carbonate (iBC), PC-EC, and EMC-DMC. Many of these are among the most frequently used solvent systems for making the nonaqueous electrolytes for lithium batteries. The phase diagrams of these carbonate systems are all of the simple eutectic type but with vastly different particular features. Comparison of these phase diagrams shows that to expand the liquid region of a carbonate system toward low temperature, the two components of the system need to have comparable melting temperatures and compatible molecular structures. These results are consistent with thermodynamic considerations and have significant practical implications.

  15. Production of bio-based materials using photobioreactors with binary cultures

    DOE Patents [OSTI]

    Beliaev, Alex S; Pinchuk, Grigoriy E; Hill, Eric A; Fredrickson, Jim K

    2013-08-27T23:59:59.000Z

    A method, device and system for producing preselected products, (either finished products or preselected intermediary products) from biobased precursors or CO.sub.2 and/or bicarbonate. The principal features of the present invention include a method wherein a binary culture is incubated with a biobased precursor in a closed system to transform at least a portion of the biobased precursor to a preselected product. The present invention provides a method of cultivation that does not need sparging of a closed bioreactor to remove or add a gaseous byproduct or nutrient from a liquid medium. This improvement leads to significant savings in energy consumption and allows for the design of photobioreactors of any desired shape. The present invention also allows for the use of a variety of types of waste materials to be used as the organic starting material.

  16. Bicontinuous and mixed gels in binary mixtures of patchy colloidal particles

    E-Print Network [OSTI]

    Daniel de las Heras; Jos Maria Tavares; Margarida M. Telo da Gama

    2011-11-16T23:59:59.000Z

    We investigate the thermodynamics and percolation regimes of model binary mixtures of patchy colloidal particles. The particles of each species have three sites of two types, one of which promotes bonding of particles of the same species while the other promotes bonding of different species. We find up to four percolated structures at low temperatures and densities: two gels where only one species percolates, a mixed gel where particles of both species percolate but neither species percolates separately, and a bicontinuous gel where particles of both species percolate separately forming two interconnected networks. The competition between the entropy and the energy of bonding drives the stability of the different percolating structures. Appropriate mixtures exhibit one or more connectivity transitions between the mixed and bicontinuous gels, as the temperature and/or the composition changes.

  17. Assignment Types UTS LIBRARY

    E-Print Network [OSTI]

    University of Technology, Sydney

    Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing

  18. Lifting Integrity Constraints in Binary Aggregation Umberto Grandi

    E-Print Network [OSTI]

    Endriss, Ulle

    Lifting Integrity Constraints in Binary Aggregation Umberto Grandi and Ulle Endriss Institute language and we explore the question of whether or not a given aggregation procedure will lift a given, this discipline has received increasing attention in Artificial Intelligence (AI), as testified by a large number

  19. Production and Injection data for NV Binary facilities

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

    Mines, Greg

    Excel files are provided with well production and injection data for binary facilities in Nevada. The files contain the data that reported montly to the Nevada Bureau of Mines and Geology (NBMG) by the facility operators. this data has been complied into Excel spreadsheets for each of the facilities given on the NBMG web site.

  20. Production and Injection data for NV Binary facilities

    SciTech Connect (OSTI)

    Mines, Greg

    2013-12-24T23:59:59.000Z

    Excel files are provided with well production and injection data for binary facilities in Nevada. The files contain the data that reported montly to the Nevada Bureau of Mines and Geology (NBMG) by the facility operators. this data has been complied into Excel spreadsheets for each of the facilities given on the NBMG web site.

  1. Synthesis and characterization of nanocrystalline binary and ternary intermetallic compounds

    E-Print Network [OSTI]

    Leonard, Brian Matthew

    2009-05-15T23:59:59.000Z

    nanocrystalline powders. Using this process, I was able to access several binary and ternary intermetallics, including two new phases: AuCuSn2 and AuNiSn2. These compounds were isolated as nanocrystals using low temperature solution synthesis techniques, which had...

  2. Accumulate-Repeat-Accumulate Codes: Systematic Codes Achieving the Binary

    E-Print Network [OSTI]

    Sason, Igal

    Accumulate-Repeat-Accumulate Codes: Systematic Codes Achieving the Binary Erasure Channel Capacity@ee.technion.ac.il Abstract The paper introduces ensembles of accumulate-repeat-accumulate (ARA) codes which asymp- totically by the first capacity-achieving ensembles of ir- regular repeat-accumulate (IRA) codes with bounded complexity

  3. Binary and recycled pulsars: 30 years after observational discovery

    E-Print Network [OSTI]

    G S Bisnovatyi-Kogan

    2006-11-13T23:59:59.000Z

    Binary radio pulsars, first discovered by Hulse and Taylor in 1974 [1], are a unique tool for experimentally testing general relativity (GR), whose validity has been confirmed with a precision unavailable in laboratory experiments. In particular, indirect evidence of the existence of gravitational waves has been obtained. Radio pulsars in binary systems (which have come to be known as recycled) have completed the accretion stage, during which neutron star spins reach millisecond periods and their magnetic fields decay 2 to 4 orders of magnitude more weakly than ordinary radio pulsars. Among about a hundred known recycled pulsars, many have turned out to be single neutron stars. The high concentration of single recycled pulsars in globular clusters suggests that close stellar encounters are highly instrumental in the loss of the companion. A system of one recycled pulsar and one 'normal' one discovered in 2004 is the most compact among binaries containing recycled pulsars [2]. Together with the presence of two pulsars in one system, this suggests new prospects for further essential improvements in testing GR. This paper considers theoretical predictions of binary pulsars, their evolutionary formation, and mechanisms by which their companions may be lost. The use of recycled pulsars in testing GR is discussed and their possible relation to the most intriguing objects in the universe, cosmic gamma-ray bursts, is examined.

  4. Coal liquefaction process using pretreatment with a binary solvent mixture

    DOE Patents [OSTI]

    Miller, Robert N. (Allentown, PA)

    1986-01-01T23:59:59.000Z

    An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300.degree. C. before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil.

  5. Detecting gravitational waves from highly eccentric compact binaries

    E-Print Network [OSTI]

    Kai Sheng Tai; Sean T. McWilliams; Frans Pretorius

    2014-03-30T23:59:59.000Z

    In dense stellar regions, highly eccentric binaries of black holes and neutron stars can form through various n-body interactions. Such a binary could emit a significant fraction of its binding energy in a sequence of largely isolated gravitational wave bursts prior to merger. Given expected black hole and neutron star masses, many such systems will emit these repeated bursts at frequencies within the sensitive band of contemporary ground-based gravitational wave detectors. Unfortunately, existing gravitational wave searches are ill-suited to detect these signals. In this work, we adapt a "power stacking" method to the detection of gravitational wave signals from highly eccentric binaries. We implement this method as an extension of the Q-transform, a projection onto a multiresolution basis of windowed complex exponentials that has previously been used to analyze data from the network of LIGO/Virgo detectors. Our method searches for excess power over an ensemble of time-frequency tiles. We characterize the performance of our method using Monte Carlo experiments with signals injected in simulated detector noise. Our results indicate that the power stacking method achieves substantially better sensitivity to eccentric binary signals than existing localized burst searches.

  6. Dixie Valley Binary Cycle Production Data 2013 YTD

    SciTech Connect (OSTI)

    Lee, Vitaly

    2013-10-18T23:59:59.000Z

    Proving the technical and economic feasibility of utilizing the available unused heat to generate additional electric power from a binary power plant from the low-temperature brine at the Dixie Valley Geothermal Power Plant. Monthly data for Jan 2013-September 2013

  7. Robust Target Localization from Binary Decisions in Wireless Sensor Networks

    E-Print Network [OSTI]

    Michailidis, George

    Robust Target Localization from Binary Decisions in Wireless Sensor Networks Natallia Katenka Wireless sensor networks (WSN) are becoming an important tool in a variety of tasks, including mon- itoring targets and localizing multiple targets are also considered. Keywords: wireless sensor network, target

  8. First-post-Newtonian quadrupole tidal interactions in binary systems

    E-Print Network [OSTI]

    Justin Vines; 蒩nna . Flanagan

    2014-10-09T23:59:59.000Z

    We consider tidal coupling in a binary stellar system to first-post-Newtonian order. We derive the orbital equations of motion for bodies with spins and mass quadrupole moments and show that they conserve the total linear momentum of the binary. We note that spin-orbit coupling must be included in a 1PN treatment of tidal interactions in order to maintain consistency (except in the special case of adiabatically induced quadrupoles); inclusion of 1PN quadrupolar tidal effects while omitting spin effects would lead to a failure of momentum conservation for generic evolution of the quadrupoles. We use momentum conservation to specialize our analysis to the system's center-of-mass-energy frame; we find the binary's relative equation of motion in this frame and also present a generalized Lagrangian from which it can be derived. We then specialize to the case in which the quadrupole moment is adiabatically induced by the tidal field (in which case it is consistent to ignore spin effects). We show how the adiabatic dynamics for the quadrupole can be incorporated into our action principle and present the simplified orbital equations of motion and conserved energy for the adiabatic case. These results are relevant to gravitational wave signals from inspiralling binary neutron stars.

  9. A detection pipeline for galactic binaries in LISA data

    E-Print Network [OSTI]

    Tyson B. Littenberg

    2011-06-30T23:59:59.000Z

    The Galaxy is suspected to contain hundreds of millions of binary white dwarf systems, a large fraction of which will have sufficiently small orbital period to emit gravitational radiation in band for space-based gravitational wave detectors such as the Laser Interferometer Space Antenna (LISA). LISA's main science goal is the detection of cosmological events (supermassive black hole mergers, etc.) however the gravitational signal from the galaxy will be the dominant contribution to the data -- including instrumental noise -- over approximately two decades in frequency. The catalogue of detectable binary systems will serve as an unparalleled means of studying the Galaxy. Furthermore, to maximize the scientific return from the mission, the data must be "cleansed" of the galactic foreground. We will present an algorithm that can accurately resolve and subtract >10000 of these sources from simulated data supplied by the Mock LISA Data Challenge Task Force. Using the time evolution of the gravitational wave frequency, we will reconstruct the position of the recovered binaries and show how LISA will sample the entire compact binary population in the Galaxy.

  10. Reliable Computation of Binary Parameters in Activity Coefficient Models

    E-Print Network [OSTI]

    Stadtherr, Mark A.

    phase equilibria. The technique is demonstrated with examples using the NRTL and electrolyte-NRTL (eNRTL) models. In two of the NRTL examples, results are found that contradict previous work. In the eNRTL time that a method for parameter estimation in the eNRTL model from binary LLE data (mutual solubility

  11. Optimization Methods for Binary Sequences The Merit Factor Problem

    E-Print Network [OSTI]

    Optimization Methods for Binary Sequences 颅 The Merit Factor Problem Ron Ferguson, Joshua Knauer SFU MOCAA Project Leader: Peter Borwein MITACS 6th Annual Conference, May, 2005 Abstract Optimization of much interest in combinatorial optimization, communications engineering, and analytic number theory

  12. A New Merging Double Degenerate Binary in the Solar Neighborhood

    E-Print Network [OSTI]

    Debes, John H; Tremblay, Pier-Emmanuel; L髉ez-Morales, Mercedes; Anglada-Escud, Guillem; Napiwotzki, Ralf; Osip, David; Weinberger, Alycia

    2015-01-01T23:59:59.000Z

    Characterizing the local space density of double degenerate binary systems is a complementary approach to broad sky surveys of double degenerates to determine the expected rates of white dwarf binary mergers, in particular those that may evolve into other observable phenomena such as extreme helium stars, Am CVn systems, and supernovae Ia. However, there have been few such systems detected in local space. We report here the discovery that WD 1242$-$105, a nearby bright WD, is a double-line spectroscopic binary consisting of two degenerate DA white dwarfs of similar mass and temperature, despite it previously having been spectroscopically characterized as a single degenerate. Follow-up photometry, spectroscopy, and trigonometric parallax have been obtained in an effort to determine the fundamental parameters of each component of this system. The binary has a mass ratio of 0.7 and a trigonometric parallax of 25.5 mas, placing it at a distance of 39 pc. The system's total mass is 0.95 M$_\\odot$ and has an orbita...

  13. Binary recycled pulsars, as a most precise physical laboratory

    E-Print Network [OSTI]

    G. S. Bisnovatyi-Kogan

    2008-02-08T23:59:59.000Z

    The following problems are discussed. 1. Pulsars and close binaries. 2. Hulse-Taylor pulsar. 3. Disrupted pulsar pairs. 4. RP statistics. 5. Enhanced evaporation: formation of single RP. 6. General relativity effects: NS+NS. 7. A Double pulsar system. 8. Checking general relativity. 9. Variability of the gravitational constant. 10. Space Watch.

  14. Pre-explosion companion stars in Type Iax supernovae

    E-Print Network [OSTI]

    Liu, Zheng-Wei; Abate, Carlo; Wang, Bo

    2015-01-01T23:59:59.000Z

    Type Iax supernovae (SNe Iax) are proposed as one new sub-class of SNe Ia since they present sufficiently distinct observational properties from the bulk of SNe Ia. SNe Iax are the most common of all types of peculiar SNe by both number and rate, with an estimated rate of occurrence of about 5-30% of the total SN Ia rate. However, the progenitor systems of SNe Iax are still uncertain. Analyzing pre-explosion images at SN Iax positions provides a direct way to place strong constraints on the nature of progenitor systems of SNe Iax. In this work, we predict pre-explosion properties of binary companion stars in a variety of potential progenitor systems by performing detailed binary evolution calculations with the one-dimensional stellar evolution code STARS. This will be helpful for constraining progenitor systems of SNe Iax from their pre-explosion observations. With our binary evolution calculations, it is found that the non-degenerate helium (He) companion star to both a massive C/O WD (> 1.1 solar mass) and ...

  15. Training a Binary Classifier with the Quantum Adiabatic Algorithm

    E-Print Network [OSTI]

    Hartmut Neven; Vasil S. Denchev; Geordie Rose; William G. Macready

    2008-11-04T23:59:59.000Z

    This paper describes how to make the problem of binary classification amenable to quantum computing. A formulation is employed in which the binary classifier is constructed as a thresholded linear superposition of a set of weak classifiers. The weights in the superposition are optimized in a learning process that strives to minimize the training error as well as the number of weak classifiers used. No efficient solution to this problem is known. To bring it into a format that allows the application of adiabatic quantum computing (AQC), we first show that the bit-precision with which the weights need to be represented only grows logarithmically with the ratio of the number of training examples to the number of weak classifiers. This allows to effectively formulate the training process as a binary optimization problem. Solving it with heuristic solvers such as tabu search, we find that the resulting classifier outperforms a widely used state-of-the-art method, AdaBoost, on a variety of benchmark problems. Moreover, we discovered the interesting fact that bit-constrained learning machines often exhibit lower generalization error rates. Changing the loss function that measures the training error from 0-1 loss to least squares maps the training to quadratic unconstrained binary optimization. This corresponds to the format required by D-Wave's implementation of AQC. Simulations with heuristic solvers again yield results better than those obtained with boosting approaches. Since the resulting quadratic binary program is NP-hard, additional gains can be expected from applying the actual quantum processor.

  16. Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars

    E-Print Network [OSTI]

    Dong Lai

    1994-04-25T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of $10-100$ Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. However, since the coupling between the g-mode and the tidal potential is rather weak, the amount of energy transfer during a resonance and the induced orbital phase error are very small. Resonant excitations of the g-modes play an important role in tidal heating of binary neutron stars. Without the resonances, viscous dissipation is effective only when the stars are close to contact. The resonant oscillations result in dissipation at much larger orbital separation. The actual amount of tidal heating depends on the viscosity of the neutron star. Using the microscopic viscosity, we find that the binary neutron stars are heated to a temperature $\\sim 10^8$ K before they come into contact.

  17. WEST VIRGINIA UNIVERSITY is the owner of all rights, title and interest in and to the following Indicia, which includes trademarks, service marks, trade names, designs, logos, seals and symbols.

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    APPENDIX B WEST VIRGINIA UNIVERSITY is the owner of all rights, title and interest: The marks of West Virginia University of are controlled under a licensing program administered Licensing Company. Yes No Restrictions WEST VIRGINIA UNIVERSITY庐 MOUNTAINEERS庐 路 University seal permitted

  18. BOWLING GREEN STATE UNIVERSITY is the owner of all rights, title and interest in and to the following Indicia, which includes trademarks, service marks, trade names, designs, logos, seals and symbols.

    E-Print Network [OSTI]

    Moore, Paul A.

    APPENDIX B BOWLING GREEN STATE UNIVERSITY is the owner of all rights, title and interest 1126 BLACK WHITE RA TBD RA 2273 BLACK WHITE NOTE: The marks of Bowling Green State University University 庐 Bowling Green 庐 Bowling Green Falcons 庐 Bowling Green State University Falcons 庐 BGSU 庐 BGSU

  19. *Intel and the Intel logo are registered trademarks of Intel Corporation. Other brands and names are the property of their respective owners The Concurrent Collections (CnC) Parallel Programming

    E-Print Network [OSTI]

    Hazelwood, Kim

    *Intel and the Intel logo are registered trademarks of Intel Corporation. Other brands and names of their respective owners *Intel and the Intel logo are registered trademarks of Intel Corporation. Other brands *Intel and the Intel logo are registered trademarks of Intel Corporation. Other brands and names

  20. Efficiency of mass transfer in massive close binaries, Tests from double-lined eclipsing binaries in the SMC

    E-Print Network [OSTI]

    S. E. de Mink; O. R. Pols; R. W. Hilditch

    2007-03-19T23:59:59.000Z

    One of the major uncertainties in close binary evolution is the efficiency of mass transfer beta: the fraction of transferred mass that is accreted by a secondary star. We attempt to constrain the mass-transfer efficiency for short-period massive binaries undergoing case A mass transfer. We present a grid of about 20,000 detailed binary evolution tracks with primary masses 3.5-35 Msun, orbital periods 1-5 days at a metallicity Z=0.004, assuming both conservative and non-conservative mass transfer. We perform a systematic comparison, using least-squares fitting, of the computed models with a sample of 50 double-lined eclipsing binaries in the Small Magellanic Cloud, for which fundamental stellar parameters have been determined. About 60% of the systems are currently undergoing slow mass transfer. In general we find good agreement between our models and the observed detached systems. However, for many of the semi-detached systems the observed temperature ratio is more extreme than our models predict. For the 17 semi-detached systems that we are able to match, we find a large spread in the best fitting mass-transfer efficiency; no single value of beta can explain all systems. We find a hint that initially wider systems tend to fit better to less conservative models. We show the need for more accurate temperature determinations and we find that determinations of surface abundances of nitrogen and carbon can potentially constrain the mass-transfer efficiency further.

  1. CIRCUMSTELLAR ABSORPTION IN DOUBLE DETONATION TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Shen, Ken J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Guillochon, James [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Foley, Ryan J., E-mail: kenshen@astro.berkeley.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-06-20T23:59:59.000Z

    Upon formation, degenerate He core white dwarfs are surrounded by a radiative H-rich layer primarily supported by ideal gas pressure. In this Letter, we examine the effect of this H-rich layer on mass transfer in He+C/O double white dwarf binaries that will eventually merge and possibly yield a Type Ia supernova (SN Ia) in the double detonation scenario. Because its thermal profile and equation of state differ from the underlying He core, the H-rich layer is transferred stably onto the C/O white dwarf prior to the He core's tidal disruption. We find that this material is ejected from the binary system and sweeps up the surrounding interstellar medium hundreds to thousands of years before the SN Ia. The close match between the resulting circumstellar medium profiles and values inferred from recent observations of circumstellar absorption in SNe Ia gives further credence to the resurgent double detonation scenario.

  2. Types of Costs Types of Cost Estimates

    E-Print Network [OSTI]

    Boisvert, Jeff

    Types of Costs Types of Cost Estimates Methods to estimate capital costs MIN E 408: Mining% accuracy. 2-5% of pre-production capital Types of Cost Estimates #12;3. Definitive Based on definitive-even $ Production Level Fixed Cost Break-even $ Production Level Cost-Revenue Relationships Capital Costs (or

  3. Quantum Noise in Differential-type Gravitational-wave Interferometer and Signal Recycling

    E-Print Network [OSTI]

    Atsushi Nishizawa; Seiji Kawamura; Masa-aki Sakagami

    2007-06-03T23:59:59.000Z

    There exists the standard quantum limit (SQL), derived from Heisenberg's uncertainty relation, in the sensitivity of laser interferometer gravitational-wave detectors. However, in the context of a full quantum-mechanical approach, SQL can be overcome using the correlation of shot noise and radiation-pressure noise. So far, signal recycling, which is one of the methods to overcome SQL, is considered only in a recombined-type interferometer such as Advanced-LIGO, LCGT, and GEO600. In this paper, we investigated quantum noise and the possibility of signal recycling in a differential-type interferometer. As a result, we found that signal recycling is possible and creates at most three dips in the sensitivity curve of the detector. Then, taking advantage of the third additional dip and comparing the sensitivity of a differential-type interferometer with that of a next-generation Japanese GW interferometer, LCGT, we found that SNR of inspiral binary is improved by a factor of 1.43 for neutron star binary, 2.28 for 50 M_sun black hole binary, and 2.94 for 100 M_sun black hole binary. We also found that power recycling to increase laser power is possible in our signal-recycling configuration of a detector.

  4. Accretion Disc Evolution in Single and Binary T Tauri Stars

    E-Print Network [OSTI]

    Philip J. Armitage; C. J. Clarke; C. A. Tout

    1998-10-30T23:59:59.000Z

    We present theoretical models for the evolution of T Tauri stars surrounded by circumstellar discs. The models include the effects of pre-main-sequence stellar and time dependent disc evolution, and incorporate the effects of stellar magnetic fields acting on the inner disc. For single stars, consistency with observations in Taurus-Auriga demands that disc dispersal occurs rapidly, on much less than the viscous timescale of the disc, at roughly the epoch when heating by stellar radiation first dominates over internal viscous dissipation. Applying the models to close binaries, we find that because the initial conditions for discs in binaries are uncertain, studies of extreme mass ratio systems are required to provide a stringent test of theoretical disc evolution models. We also note that no correlation of the infra-red colours of T Tauri stars with their rotation rate is observed, in apparent contradiction to the predictions of simple magnetospheric accretion models.

  5. General Relativistic Binary Merger Simulations and Short Gamma Ray Bursts

    E-Print Network [OSTI]

    Joshua A. Faber; Thomas W. Baumgarte; Stuart L. Shapiro; Keisuke Taniguchi

    2006-03-10T23:59:59.000Z

    The recent localization of some short-hard gamma ray bursts (GRBs) in galaxies with low star formation rates has lent support to the suggestion that these events result from compact object binary mergers. We discuss how new simulations in general relativity are helping to identify the central engine of short-hard GRBs. Motivated by our latest relativistic black hole-neutron star merger calculations, we discuss a scenario in which these events may trigger short-hard GRBs, and compare this model to competing relativistic models involving binary neutron star mergers and the delayed collapse of hypermassive neutron stars. Distinguishing features of these models may help guide future GRB and gravitational wave observations to identify the nature of the sources.

  6. Planet formation around binary stars: Tatooine made easy

    E-Print Network [OSTI]

    Bromley, B C

    2015-01-01T23:59:59.000Z

    We examine characteristics of circumbinary orbits in the context of current planet formation scenarios. Analytical perturbation theory predicts the existence of nested circumbinary orbits that are generalizations of circular orbits in a Keplerian potential. They contain forced epicyclic motion aligned with the binary as well as higher frequency oscillations, yet they do not cross, even in the presence of massive disks and perturbations from large planets. For this reason, dissipative gas and planetesimals can settle onto these "most circular" orbits, facilitating the growth of protoplanets. Outside a region close to the binary where orbits are generally unstable, circumbinary planets form in much the same way as their cousins around a single star. Here, we review the theory and confirm its predictions with a suite of representative simulations. We then consider the circumbinary planets discovered with NASA's Kepler satellite. These Neptune- and Jupiter-size planets, or their planetesimal precursors, may have ...

  7. Bayesian decision making in human collectives with binary choices

    E-Print Network [OSTI]

    Egu韑uz, V韈tor M; Fern醤dez-Gracia, J

    2015-01-01T23:59:59.000Z

    Here we focus on the description of the mechanisms behind the process of information aggregation and decision making, a basic step to understand emergent phenomena in society, such as trends, information spreading or the wisdom of crowds. In many situations, agents choose between discrete options. We analyze experimental data on binary opinion choices in humans. The data consists of two separate experiments in which humans answer questions with a binary response, where one is correct and the other is incorrect. The questions are answered without and with information on the answers of some previous participants. We find that a Bayesian approach captures the probability of choosing one of the answers. The influence of peers is uncorrelated with the difficulty of the question. The data is inconsistent with Weber's law, which states that the probability of choosing an option depends on the proportion of previous answers choosing that option and not on the total number of those answers. Last, the present Bayesian ...

  8. Simulations of binary black hole mergers using spectral methods

    SciTech Connect (OSTI)

    Szilagyi, Bela; Lindblom, Lee; Scheel, Mark A. [Theoretical Astrophysics 350-17, California Institute of Technology, Pasadena, California 91125 (United States)

    2009-12-15T23:59:59.000Z

    Several improvements in numerical methods and gauge choice are presented that make it possible now to perform simulations of the merger and ringdown phases of 'generic' binary black hole evolutions using the pseudospectral evolution code SpEC. These improvements include the use of a new damped-wave gauge condition, a new grid structure with appropriate filtering that improves stability, and better adaptivity in conforming the grid structures to the shapes and sizes of the black holes. Simulations illustrating the success of these new methods are presented for a variety of binary black hole systems. These include fairly generic systems with unequal masses (up to 2 ratio 1 mass ratios), and spins (with magnitudes up to 0.4M{sup 2}) pointing in various directions.

  9. Kinetic Theory for Binary Granular Mixtures at Low-Density

    E-Print Network [OSTI]

    Vicente Garzo

    2007-04-10T23:59:59.000Z

    Many features of granular media can be modelled as a fluid of hard spheres with {\\em inelastic} collisions. Under rapid flow conditions, the macroscopic behavior of grains can be described through hydrodynamic equations. At low-density, a fundamental basis for the derivation of the hydrodynamic equations and explicit expressions for the transport coefficients appearing in them is provided by the Boltzmann kinetic theory conveniently modified to account for inelastic binary collisions. The goal of this chapter is to give an overview of the recent advances made for binary granular gases by using kinetic theory tools. Some of the results presented here cover aspects such as transport properties, energy nonequipartition, instabilities, segregation or mixing, non-Newtonian behavior, .... In addition, comparison of the analytical results with those obtained from Monte Carlo and molecular dynamics simulations is also carried out, showing the reliability of kinetic theory to describe granular flows even for strong dissipation.

  10. A fractal set from the binary reflected Gray code

    E-Print Network [OSTI]

    J. A. Oteo; J. Ros

    2005-10-14T23:59:59.000Z

    The permutation associated with the decimal expression of the binary reflected Gray code with $N$ bits is considered. Its cycle structure is studied. Considered as a set of points, its self-similarity is pointed out. As a fractal, it is shown to be the attractor of a IFS. For large values of $N$ the set is examined from the point of view of time series analysis

  11. Coal liquefaction process using pretreatment with a binary solvent mixture

    DOE Patents [OSTI]

    Miller, R.N.

    1986-10-14T23:59:59.000Z

    An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300 C before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil. 1 fig.

  12. Linear Complexity Lossy Compressor for Binary Redundant Memoryless Sources

    E-Print Network [OSTI]

    Mimura, Kazushi

    2011-01-01T23:59:59.000Z

    A lossy compression algorithm for binary redundant i.i.d. sources is presented. The proposed scheme is based on sparse graph codes. By introducing a nonlinear function, redundant memoryless sequences can be compressed. We propose a linear complexity compressor based on the extended belief propagation, into which an inertia term is heuristically introduced, and show that it has near optimal performance for moderate blocklengths.

  13. Gravitational-wave modes from precessing black-hole binaries

    E-Print Network [OSTI]

    Michael Boyle; Lawrence E. Kidder; Serguei Ossokine; Harald P. Pfeiffer

    2014-09-22T23:59:59.000Z

    Gravitational waves from precessing black-hole binaries exhibit features that are absent in nonprecessing systems. The most prominent of these is a parity-violating asymmetry that beams energy and linear momentum preferentially along or opposite to the orbital angular momentum, leading to recoil of the binary. The asymmetry will appear as amplitude and phase modulations at the orbital frequency. For strongly precessing systems, it accounts for at least 3% amplitude modulation for binaries in the sensitivity band of ground-based gravitational-wave detectors, and can exceed 50% for massive systems. Such asymmetric features are also clearly visible when the waves are decomposed into modes of spin-weighted spherical harmonics, and are inherent in the waves themselves---rather than resulting from residual eccentricity in numerical simulations, or from mode-mixing due to precession. In particular, there is generically no instantaneous frame for which the mode decomposition will have any symmetry. We introduce a method to simplify the expressions for waveforms given in analytical relativity, which can be used to combine existing high-order waveforms for nonprecessing systems with expressions for the precessing contributions, leading to improved accuracy and a unified treatment of precessing and nonprecessing binaries. Using this method, it is possible to clarify the nature and the origins of the asymmetries and show the effects of asymmetry on recoils more clearly. We present post-Newtonian (PN) expressions for the waveform modes that include these terms, complete to the relative 2PN level in spin (proportional to $v^4/c^4$ times a certain combination of the spins). Comparing the results of those expressions to numerical results, we find good qualitative agreement. We also demonstrate how these expressions can be used to efficiently calculate waveforms for gravitational-wave astronomy.

  14. Short Gamma-Ray Bursts from Binary Neutron Star Mergers

    E-Print Network [OSTI]

    Roland Oechslin; Thomas Janka

    2006-04-27T23:59:59.000Z

    We present the results from new relativistic hydrodynamic simulations of binary neutron star mergers using realistic non-zero temperature equations of state. We vary several unknown parameters in the system such as the neutron star (NS) masses, their spins and the nuclear equation of state. The results are then investigated with special focus on the post-merger torus-remnant system. Observational implications on the Gamma-ray burst (GRB) energetics are discussed and compared with recent observations.

  15. A study of diffusion in binary solutions using spin echoes

    E-Print Network [OSTI]

    Rousseau, Cecil Clyde

    1962-01-01T23:59:59.000Z

    of Experimentally Determined Diffusion Coefficients of Cyclohexane and Acetone with the Results of NcCall, Douglass, and Anderson . . . . . . . . . 23 INTRODUCTION The available descriptions of the liquid state form a continuous spectrum that extends from... the liquid with unit velocity. The intrinsic diffusion coefficient is now given by Di kT Equation (1-11) is known as the Einstein relation. Thus far, no explicit statement has been made concerning diffusion in binary systems. In addition to the intrinsic...

  16. Development of a Physiologically Based Pharmacokinetic and Pharmacodynamic Model to Determine Dosimetry and Cholinesterase Inhibition for a Binary Mixture of Chlorpyrifos and Diazinon in the Rat

    SciTech Connect (OSTI)

    Timchalk, Chuck; Poet, Torka S.

    2008-05-01T23:59:59.000Z

    Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models have been developed and validated for the organophosphorus (OP) insecticides chlorpyrifos (CPF) and diazinon (DZN). Based on similar pharmacokinetic and mode of action properties it is anticipated that these OPs could interact at a number of important metabolic steps including: CYP450 mediated activation/detoxification, and blood/tissue cholinesterase (ChE) binding/inhibition. We developed a binary PBPK/PD model for CPF, DZN and their metabolites based on previously published models for the individual insecticides. The metabolic interactions (CYP450) between CPF and DZN were evaluated in vitro and suggests that CPF is more substantially metabolized to its oxon metabolite than is DZN. These data are consistent with their observed in vivo relative potency (CPF>DZN). Each insecticide inhibited the other抯 in vitro metabolism in a concentration-dependent manner. The PBPK model code used to described the metabolism of CPF and DZN was modified to reflect the type of inhibition kinetics (i.e. competitive vs. non-competitive). The binary model was then evaluated against previously published rodent dosimetry and ChE inhibition data for the mixture. The PBPK/PD model simulations of the acute oral exposure to single- (15 mg/kg) vs. binary-mixtures (15+15 mg/kg) of CFP and DZN at this lower dose resulted in no differences in the predicted pharmacokinetics of either the parent OPs or their respective metabolites; whereas, a binary oral dose of CPF+DZN at 60+60 mg/kg did result in observable changes in the DZN pharmacokinetics. Cmax was more reasonably fit by modifying the absorption parameters. It is anticipated that at low environmentally relevant binary doses, most likely to be encountered in occupational or environmental related exposures, that the pharmacokinetics are expected to be linear, and ChE inhibition dose-additive.

  17. LONG-TERM STABLE EQUILIBRIA FOR SYNCHRONOUS BINARY ASTEROIDS

    SciTech Connect (OSTI)

    Jacobson, Seth A. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, CO 80309 (United States); Scheeres, Daniel J. [Department of Aerospace Engineering Sciences, University of Colorado at Boulder, Boulder, CO 80309 (United States)

    2011-07-20T23:59:59.000Z

    Synchronous binary asteroids may exist in a long-term stable equilibrium, where the opposing torques from mutual body tides and the binary YORP (BYORP) effect cancel. Interior of this equilibrium, mutual body tides are stronger than the BYORP effect and the mutual orbit semimajor axis expands to the equilibrium; outside of the equilibrium, the BYORP effect dominates the evolution and the system semimajor axis will contract to the equilibrium. If the observed population of small (0.1-10 km diameter) synchronous binaries are in static configurations that are no longer evolving, then this would be confirmed by a null result in the observational tests for the BYORP effect. The confirmed existence of this equilibrium combined with a shape model of the secondary of the system enables the direct study of asteroid geophysics through the tidal theory. The observed synchronous asteroid population cannot exist in this equilibrium if described by the canonical 'monolithic' geophysical model. The 'rubble pile' geophysical model proposed by Goldreich and Sari is sufficient, however it predicts a tidal Love number directly proportional to the radius of the asteroid, while the best fit to the data predicts a tidal Love number inversely proportional to the radius. This deviation from the canonical and Goldreich and Sari models motivates future study of asteroid geophysics. Ongoing BYORP detection campaigns will determine whether these systems are in an equilibrium, and future determination of secondary shapes will allow direct determination of asteroid geophysical parameters.

  18. Resonant oscillations and tidal heating in coalescing binary neutron stars

    E-Print Network [OSTI]

    Lai, D

    1994-01-01T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of 10-100 Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. ...

  19. PPl 15: The First Brown Dwarf Spectroscopic Binary

    E-Print Network [OSTI]

    Gibor Basri; Eduardo Martin

    1999-08-02T23:59:59.000Z

    PPl 15 is the first object to have been confirmed as a brown dwarf by the lithium test (in 1995), though its inferred mass was very close to the substellar limit. It is a member of the Pleiades open cluster. Its position in a cluster color-magnitude diagram suggested that it might be binary, and preliminary indications that it is a double-lined spectroscopic binary were reported by us in 1997. Here we report on the results of a consecutive week of Keck HIRES observations of this system, which yield its orbit. It has a period of about 5.8 days, and an eccentricity of 0.4+/-0.05. The rotation of the stars is slow for this class of objects. Because the system luminosity is divided between 2 objects with a mass ratio of 0.85, this renders each of them an incontrovertible brown dwarf, with masses between 60-70 jupiters. We show that component B is a little redder than A by studying their wavelength-dependent line ratios, and that this variation is compatible with the mass ratio. We confirm that the system has lithium, but cannot support the original conclusion that it is depleted (which would be surprising, given the new masses). This is a system of very close objects which, if they had combined, would have produced a low mass star. We discuss the implications of this discovery for the theories of binary formation and formation of very low mass objects.

  20. A Lossless Fuzzy Binary AND/OR Compressor

    E-Print Network [OSTI]

    Alipour, Philip B

    2009-01-01T23:59:59.000Z

    In this report, a new fuzzy 2bit-AND parallel-to-OR, or simply, a fuzzy binary AND/OR (FBAR) text data compression model as an algorithm is suggested for bettering spatial locality limits on nodes during database transactions. The current model incorporates a four-layer application technique: string-to-AND/OR pairwise binary bit + fuzzy quantum with noise conversions. This technique promotes a lossless data compression ratio of 2:1 up to values approximately = 3:1, generating a spatially-efficient compressed data file compared to nowadays data compressors. Data decompression/specific data reconstruction initiates an AND/OR pattern match technique in respect of fuzzy quantum indicators in the binary function field. The reconstruction of data occurs in the 4th layer using encryption methods. It is hypothesized that significant data compression ratio of 2n:1 for n>3:1 ratios, e.g., 32~64:1 are achievable via fuzzy qubit indexing over classical byte blocks for every bit position fragmented into a (1/2 upper +1/2 ...

  1. Improved methods for simulating nearly extremal binary black holes

    E-Print Network [OSTI]

    Mark A. Scheel; Matthew Giesler; Daniel A. Hemberger; Geoffrey Lovelace; Kevin Kuper; Michael Boyle; Bela Szilagyi; Lawrence E. Kidder

    2014-12-04T23:59:59.000Z

    Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect. Predicting the gravitational waves emitted by merging black holes requires numerical-relativity simulations, but these simulations are especially challenging when one or both holes have mass $m$ and spin $S$ exceeding the Bowen-York limit of $S/m^2=0.93$. We present improved methods that enable us to simulate merging, nearly extremal black holes more robustly and more efficiently. We use these methods to simulate an unequal-mass, precessing binary black hole coalescence, where the larger black hole has $S/m^2=0.99$. We also use these methods to simulate a non-precessing binary black hole coalescence, where both black holes have $S/m^2=0.994$, nearly reaching the Novikov-Thorne upper bound for holes spun up by thin accretion disks. We demonstrate numerical convergence and estimate the numerical errors of the waveforms; we compare numerical waveforms from our simulations with post-Newtonian and effective-one-body waveforms; we compare the evolution of the black-hole masses and spins with analytic predictions; and we explore the effect of increasing spin magnitude on the orbital dynamics (the so-called "orbital hangup" effect).

  2. Simulating merging binary black holes with nearly extremal spins

    SciTech Connect (OSTI)

    Lovelace, Geoffrey [Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, 14853 (United States); Scheel, Mark A.; Szilagyi, Bela [Theoretical Astrophysics 350-17, California Institute of Technology, Pasadena, California 91125 (United States)

    2011-01-15T23:59:59.000Z

    Astrophysically realistic black holes may have spins that are nearly extremal (i.e., close to 1 in dimensionless units). Numerical simulations of binary black holes are important tools both for calibrating analytical templates for gravitational-wave detection and for exploring the nonlinear dynamics of curved spacetime. However, all previous simulations of binary-black-hole inspiral, merger, and ringdown have been limited by an apparently insurmountable barrier: the merging holes' spins could not exceed 0.93, which is still a long way from the maximum possible value in terms of the physical effects of the spin. In this paper, we surpass this limit for the first time, opening the way to explore numerically the behavior of merging, nearly extremal black holes. Specifically, using an improved initial-data method suitable for binary black holes with nearly extremal spins, we simulate the inspiral (through 12.5 orbits), merger and ringdown of two equal-mass black holes with equal spins of magnitude 0.95 antialigned with the orbital angular momentum.

  3. Types of Commissioning

    Broader source: Energy.gov [DOE]

    Several commissioning types exist to address the specific needs of equipment and systems across both new and existing buildings. The following commissioning types provide a good overview.

  4. THE LOCATIONS OF SHORT GAMMA-RAY BURSTS AS EVIDENCE FOR COMPACT OBJECT BINARY PROGENITORS

    SciTech Connect (OSTI)

    Fong, W.; Berger, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-10-10T23:59:59.000Z

    We present a detailed investigation of Hubble Space Telescope rest-frame UV/optical observations of 22 short gamma-ray burst (GRB) host galaxies and sub-galactic environments. Utilizing the high angular resolution and depth of HST we characterize the host galaxy morphologies, measure precise projected physical and host-normalized offsets between the bursts and host centers, and calculate the locations of the bursts with respect to their host light distributions (rest-frame UV and optical). We calculate a median short GRB projected physical offset of 4.5 kpc, about 3.5 times larger than that for long GRBs, and find that ?25% of short GRBs have offsets of ?> 10 kpc. When compared to their host sizes, the median offset is 1.5 half-light radii (r{sub e} ), about 1.5 times larger than the values for long GRBs, core-collapse supernovae, and Type Ia supernovae. In addition, ?20% of short GRBs having offsets of ?> 5r{sub e} , and only ?25% are located within 1r{sub e} . We further find that short GRBs severely under-represent their hosts' rest-frame optical and UV light, with ?30%-45% of the bursts located in regions of their host galaxies that have no detectable stellar light, and ?55% in the regions with no UV light. Therefore, short GRBs do not occur in regions of star formation or even stellar mass. This demonstrates that the progenitor systems of short GRBs must migrate from their birth sites to their eventual explosion sites, a signature of kicks in compact object binary systems. Utilizing the full sample of offsets, we estimate natal kick velocities of ?20-140 km s{sup 1}. These independent lines of evidence provide the strongest support to date that short GRBs result from the merger of compact object binaries (NS-NS/NS-BH)

  5. Effect of squeezing on parameter estimation of gravitational waves emitted by compact binary systems

    E-Print Network [OSTI]

    Ryan Lynch; Salvatore Vitale; Lisa Barsotti; Matthew Evans; Sheila Dwyer

    2014-11-06T23:59:59.000Z

    The LIGO gravitational wave (GW) detectors will begin collecting data in 2015, with Virgo following shortly after. The use of squeezing has been proposed as a way to reduce the quantum noise without increasing the laser power, and has been successfully tested at one of the LIGO sites and at GEO in Germany. When used in Advanced LIGO without a filter cavity, the squeezer improves the performances of detectors above about 100 Hz, at the cost of a higher noise floor in the low frequency regime. Frequency-dependent squeezing, on the other hand, will lower the noise floor throughout the entire band. Squeezing technology will have a twofold impact: it will change the number of expected detections and it will impact the quality of parameter estimation for the detected signals. In this work we consider three different GW detector networks, each utilizing a different type of squeezer, all corresponding to plausible implementations. Using LALInference, a powerful Monte Carlo parameter estimation algorithm, we study how each of these networks estimates the parameters of GW signals emitted by compact binary systems, and compare the results with a baseline advanced LIGO-Virgo network. We find that, even in its simplest implementation, squeezing has a large positive impact: the sky error area of detected signals will shrink by about 30% on average, increasing the chances of finding an electromagnetic counterpart to the GW detection. Similarly, we find that the measurability of tidal deformability parameters for neutron stars in binaries increases by about 30%, which could aid in determining the equation of state of neutron stars. The degradation in the measurement of the chirp mass, as a result of the higher low-frequency noise, is shown to be negligible when compared to systematic errors.

  6. Collective properties of neutron-star X-ray binary populations of galaxies. II. Pre-low-mass X-ray binary properties, formation rates, and constraints

    SciTech Connect (OSTI)

    Bhadkamkar, H. [Astronomy and Astrophysics, Raman Research Institute, Bengaluru 560080 (India); Ghosh, P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2014-04-01T23:59:59.000Z

    We continue our exploration of the collective properties of neutron-star X-ray binaries in the stellar fields (i.e., outside globular clusters) of normal galaxies. In Paper I of this series, we considered high-mass X-ray binaries (HMXBs). In this paper (Paper II), we consider low-mass X-ray binaries (LMXBs), whose evolutionary scenario is very different from that of HMXBs. We consider the evolution of primordial binaries up to the stage where the neutron star just formed in the supernova explosion of the primary is in a binary with its low-mass, unevolved companion, and this binary has circularized tidally, producing what we call a pre-low-mass X-ray binary (pre-LMXB). We study the constraints on the formation of such pre-LMXBs in detail (since these are low-probability events), and calculate their collective properties and formation rates. To this end, we first consider the changes in the binary parameters in the various steps involved, viz., the common-envelope phase, the supernova, and the tidal evolution. This naturally leads to a clarification of the constraints. We then describe our calculation of the evolution of the distributions of primordial binary parameters into those of pre-LMXB parameters, following the standard evolutionary scenario for individual binaries. We display the latter as both bivariate and monovariate distributions, discuss their essential properties, and indicate the influences of some essential factors on these. Finally, we calculate the formation rate of these pre-LMXBs. The results of this paper will be used in a subsequent one to compute the expected X-ray luminosity function of LMXBs.

  7. FM stars II: a Fourier view of pulsating binary stars -- determining binary orbital parameters photometrically for highly eccentric cases

    E-Print Network [OSTI]

    Shibahashi, Hiromoto; Murphy, Simon J

    2015-01-01T23:59:59.000Z

    Continuous and precise space-based photometry has made it possible to measure the orbital frequency modulation of pulsating stars in binary systems with extremely high precision over long time spans. Frequency modulation caused by binary orbital motion manifests itself as a multiplet with equal spacing of the orbital frequency in the Fourier transform. The amplitudes and phases of the peaks in these multiplets reflect the orbital properties, hence the orbital parameters can be extracted by analysing such precise photometric data alone. We derive analytically the theoretical relations between the multiplet properties and the orbital parameters, and present a method for determining these parameters, including the eccentricity and the argument of periapsis, from a quintuplet or a higher order multiplet. This is achievable with the photometry alone, without spectroscopic radial velocity measurements. We apply this method to Kepler mission data of KIC8264492, KIC9651065, and KIC10990452, each of which is shown to ...

  8. A CAUTIONARY TALE: MARVELS BROWN DWARF CANDIDATE REVEALS ITSELF TO BE A VERY LONG PERIOD, HIGHLY ECCENTRIC SPECTROSCOPIC STELLAR BINARY

    SciTech Connect (OSTI)

    Mack, Claude E. III; Stassun, Keivan G.; De Lee, Nathan [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Ge, Jian; Fleming, Scott W. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL, 32611-2055 (United States); Deshpande, Rohit; Mahadevan, Suvrath [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Wisniewski, John P. [Homer L Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St, Norman, OK 73019 (United States); Gaudi, B. Scott; Eastman, Jason; Beatty, Thomas G. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Ghezzi, Luan [Observatorio Nacional, Rua Gal. Jose Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); Gonzalez Hernandez, Jonay I.; Femenia, Bruno; Mata Sanchez, Daniel [Instituto de Astrofisica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Ferreira, Leticia; Porto de Mello, Gustavo [Laboratorio Interinstitucional de e-Astronomia-LIneA, Rua Gal. Jose Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Agol, Eric [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195 (United States); Bizyaev, Dmitry, E-mail: claude.e.mack@vanderbilt.edu [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059 (United States); and others

    2013-05-15T23:59:59.000Z

    We report the discovery of a highly eccentric, double-lined spectroscopic binary star system (TYC 3010-1494-1), comprising two solar-type stars that we had initially identified as a single star with a brown dwarf companion. At the moderate resolving power of the MARVELS spectrograph and the spectrographs used for subsequent radial-velocity (RV) measurements (R {approx}< 30, 000), this particular stellar binary mimics a single-lined binary with an RV signal that would be induced by a brown dwarf companion (Msin i {approx} 50 M{sub Jup}) to a solar-type primary. At least three properties of this system allow it to masquerade as a single star with a very-low-mass companion: its large eccentricity (e {approx} 0.8), its relatively long period (P {approx} 238 days), and the approximately perpendicular orientation of the semi-major axis with respect to the line of sight ({omega} {approx} 189 Degree-Sign ). As a result of these properties, for {approx}95% of the orbit the two sets of stellar spectral lines are completely blended, and the RV measurements based on centroiding on the apparently single-lined spectrum is very well fit by an orbit solution indicative of a brown dwarf companion on a more circular orbit (e {approx} 0.3). Only during the {approx}5% of the orbit near periastron passage does the true, double-lined nature and large RV amplitude of {approx}15 km s{sup -1} reveal itself. The discovery of this binary system is an important lesson for RV surveys searching for substellar companions; at a given resolution and observing cadence, a survey will be susceptible to these kinds of astrophysical false positives for a range of orbital parameters. Finally, for surveys like MARVELS that lack the resolution for a useful line bisector analysis, it is imperative to monitor the peak of the cross-correlation function for suspicious changes in width or shape, so that such false positives can be flagged during the candidate vetting process.

  9. Evolutionary Models for Type Ib/c Supernova Progenitors

    E-Print Network [OSTI]

    Yoon, Sung-Chul

    2015-01-01T23:59:59.000Z

    Type Ib/c supernovae (SNe Ib/c) mark the deaths of hydrogen-deficient massive stars. The evolutionary scenarios for SNe Ib/c progenitors involve many important physical processes including mass loss by winds and its metallicity dependence, stellar rotation, and binary interactions. This makes SNe Ib/c an excellent test bed for stellar evolution theory. We review the main results of evolutionary models for SN Ib/c progenitors available in the literature and their confrontation with recent observations. We argue that the nature of SN Ib/c progenitors can be significantly different for single and binary systems, and that binary evolution models can explain the ejecta masses derived from SN Ib/c light curves, the distribution of SN Ib/c sites in their host galaxies, and the optical magnitudes of the tentative progenitor candidate of iPTF13bvn. We emphasize the importance of early-time observations of light curves and spectra, accurate measurements of helium mass in SN Ib/c ejecta, and systematic studies about the...

  10. A new method of determining the inclination angle in interacting binaries

    E-Print Network [OSTI]

    Tariq Shahbaz

    1998-03-25T23:59:59.000Z

    We describe a method of determining the system parameters in non-eclipsing interacting binaries. We find that the extent to which an observer sees the shape of the Roche-lobe of the secondary star governs the amount of distortion of the absorption line profiles. The width and degree of asymmetry of the phase-resolved absorption line profiles show a characteristic shape, which depends primarily on the binary inclination and gravity darkening exponent. We show that, in principle, by obtaining high spectral and time resolution spectra of quiescent cataclysmic variables or low mass X-ray binaries in which the mass-losing star is visible, fitting the shape of absorption line profiles will allow one to determine not only the mass function of the binary, but also the binary inclination and hence the mass of the binary components.

  11. Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions

    E-Print Network [OSTI]

    Skowron, J; Gould, A; Dong, Subo; Monard, L A G; Han, C; Nelson, C R; McCormick, J; Moorhouse, D; Thornley, G; Maury, A; Bramich, D M; Greenhill, J; Kozlowski, S; Bond, I; Poleski, R; Wyrzykowski, L; Ulaczyk, K; Kubiak, M; Szymanski, M K; Pietrzynski, G; Soszynski, I; Gaudi, B S; Yee, J C; Hung, L -W; Pogge, R W; DePoy, D L; Lee, C -U; Park, B -G; Allen, W; Mallia, F; Drummond, J; Bolt, G; Allan, A; Browne, P; Clay, N; Dominik, M; Fraser, S; Horne, K; Kains, N; Mottram, C; Snodgrass, C; Steele, I; Street, R A; Tsapras, Y; Abe, F; Bennett, D P; Botzler, C S; Douchin, D; Freeman, M; Fukui, A; Furusawa, K; Hayashi, F; Hearnshaw, J B; Hosaka, S; Itow, Y; Kamiya, K; Kilmartin, P M; Korpela, A; Lin, W; Ling, C H; Makita, S; Masuda, K; Matsubara, Y; Muraki, Y; Nagayama, T; Miyake, N; Nishimoto, K; Ohnishi, K; Perrott, Y C; Rattenbury, N; Saito, To; Skuljan, L; Sullivan, D J; Sumi, T; Suzuki, D; Sweatman, W L; Tristram, P J; Wada, K; Yock, P C M; Beaulieu, J -P; Fouque, P; Albrow, M D; Batista, V; Brillant, S; Caldwell, J A R; Cassan, A; Cole, A; Cook, K H; Coutures, Ch; Dieters, S; Prester, D Dominis; Donatowicz, J; Kane, S R; Kubas, D; Marquette, J -B; Martin, R; Menzies, J; Sahu, K C; Wambsganss, J; Williams, A; Zub, M

    2011-01-01T23:59:59.000Z

    We present the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible by a confluence of two relatively unusual circumstances. First, the binary lens is bright enough (I=15.6) to permit Doppler measurements. Second, we measure not only the usual 7 binary-lens parameters, but also the 'microlens parallax' (which yields the binary mass) and two components of the instantaneous orbital velocity. Thus we measure, effectively, 6 'Kepler+1' parameters (two instantaneous positions, two instantaneous velocities, the binary total mass, and the mass ratio). Since Doppler observations of the brighter binary component determine 5 Kepler parameters (period, velocity amplitude, eccentricity, phase, and position of periapsis), while the same spectroscopy yields the mass of the primary, the combined Doppler + microlensing observations would be overconstrained by 6 + (5 + 1) - (7 + 1) = 4 degrees of freedom. This mak...

  12. The Equations of Motion of Compact Binaries in the Neighborhood of Supermassive Black Hole

    SciTech Connect (OSTI)

    Gorbatsievich, Alexander; Bobrik, Alexey [Belarusian state university, Nezavisimosti Av., 4, 220030 Minsk (Belarus)

    2010-03-24T23:59:59.000Z

    By the use of Einstein-Infeld-Hoffmann method, the equations of motion of a binary star system in the field of a supermassive black hole are derived. In spite of the fact that the motion of a binary system as a whole can be relativistic or even ultra-relativistic with respect to the supermassive black hole, it is shown, that under the assumption of non-relativistic relative motion of the stars in binary system, the motion of the binary system as a whole satisfies the Mathisson-Papapetrou equations with additional terms depending on quadrupole moments. Exemplary case of ultrarelativistic motion of a binary neutron star in the vicinity of non-rotating black hole is considered. It it shown that the motion of binary's center of mass may considerably differ from geodesic motion.

  13. Types of Costs Types of Cost Estimates

    E-Print Network [OSTI]

    Boisvert, Jeff

    05-1 Types of Costs Types of Cost Estimates Methods to estimate capital costs MIN E 408-Revenue Relationships Capital Costs (or first cost or capital investment): Expenditures made to acquire or develop capital assets Three main classes of capital costs: 1. Depreciable Investment: Investment allocated

  14. Automated eclipsing binary detection: applying the Gaia CU7 pipeline to Hipparcos

    E-Print Network [OSTI]

    Holl, Berry; Lecoeur-Ta颾i, Isabelle; Barblan, Fabio; Rimoldini, Lorenzo; Eyer, Laurent; S黺eges, Maria; Guy, Leanne; Ordo馿z-Blanco, Diego; Ruiz, Idoia; Nienartowicz, Krzysztof

    2015-01-01T23:59:59.000Z

    We demonstrate the eclipsing binary detection performance of the Gaia variability analysis and processing pipeline using Hipparcos data. The automated pipeline classifies 1,067 (0.9%) of the 118,204 Hipparcos sources as eclipsing binary candidates. The detection rate amounts to 89% (732 sources) in a subset of 819 visually confirmed eclipsing binaries, with the period correctly identified for 80% of them, and double or half periods obtained in 6% of the cases.

  15. Weight Distribution of a Class of Binary Linear Block Codes Formed from RCPC Codes

    E-Print Network [OSTI]

    Shen, Yushi Dr.; Cosman, Pamela C; Milstein, Laurence B

    2006-01-01T23:59:59.000Z

    On the weight distribution of terminated convolutionalViterbi, 揙n the weight distribution of linear block codes9, SEPTEMBER 2005 Weight Distribution of a Class of Binary

  16. Migration of massive black hole binaries in self--gravitating accretion discs: Retrograde versus prograde

    E-Print Network [OSTI]

    Constanze Roedig; Alberto Sesana

    2013-07-24T23:59:59.000Z

    We study the interplay between mass transfer, accretion and gravitational torques onto a black hole binary migrating in a self-gravitating, retrograde circumbinary disc. A direct comparison with an identical prograde disc shows that: (i) because of the absence of resonances, the cavity size is a factor a(1+e) smaller for retrograde discs; (ii) nonetheless the shrinkage of a circular binary semi--major axis, a, is identical in both cases; (iii) a circular binary in a retrograde disc remains circular while eccentric binaries grow more eccentric. For non-circular binaries, we measure the orbital decay rates and the eccentricity growth rates to be exponential as long as the binary orbits in the plane of its disc. Additionally, for these co-planar systems, we find that interaction (~ non--zero torque) stems only from the cavity edge plus a(1+e) in the disc, i.e. for dynamical purposes, the disc can be treated as a annulus of small radial extent. We find that simple 'dust' models in which the binary- disc interaction is purely gravitational can account for all main numerical results, both for prograde and retrograde discs. Furthermore, we discuss the possibility of an instability occurring for highly eccentric binaries causing it to leave the disc plane, secularly tilt and converge to a prograde system. Our results suggest that there are two stable configurations for binaries in self-gravitating discs: the special circular retrograde case and an eccentric (e~ 0.6) prograde configuration as a stable attractor.

  17. DISCOVERY OF A YOUNG L DWARF BINARY, SDSS J224953.47+004404.6AB

    SciTech Connect (OSTI)

    Allers, K. N. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Liu, Michael C.; Dupuy, Trent J.; Cushing, Michael C., E-mail: k.allers@bucknell.ed [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2010-05-20T23:59:59.000Z

    We report discovery of a young 0.''32 L dwarf binary, SDSS J2249+0044AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field brown dwarfs. Weak K I, Na I, and FeH features as well as strong VO absorption in the integrated-light J-band spectrum indicate a low surface gravity and hence young age for the system. From spatially resolved K-band spectra we determine spectral types of L3 {+-} 0.5 and L5 {+-} 1 for components A and B, respectively. SDSS J2249+0044A is spectrally very similar to G196-3B, an L3 companion to a young M2.5 field dwarf. Thus, we adopt 100 Myr (the age estimate of the G196-3 system) as the age of SDSS J2249+0044AB, but ages of 12-790 Myr are possible. By comparing our photometry to the absolute magnitudes of G196-3B, we estimate a distance to SDSS J2249+0044AB of 54 {+-} 16 pc and infer a projected separation of 17 {+-} 5 AU for the binary. Comparison of the luminosities to evolutionary models at an age of 100 Myr yields masses of 0.029 {+-} 0.006 and 0.022{sup +0.006}{sub -0.009} M{sub sun} for SDSS J2249+0044A and B, respectively. Over the possible ages of the system (12-790 Myr), the mass of SDSS J2249+0044A could range from 0.011 to 0.070 M{sub sun} and the mass of SDSS J2249+0044B could range from 0.009 to 0.065 M{sub sun}. Evolutionary models predict that either component could be burning deuterium, which could result in a mass ratio as low as 0.4, or alternatively, a reversal in the luminosities of the binary. We find a likely proper motion companion, GSC 00568-01752, which lies 48.''9 away (a projected separation of 2600 AU) and has Sloan Digital Sky Survey and Two Micron All Sky Survey colors consistent with an early M dwarf. We calculate a photometric distance to GSC 00568-01752 of 53 {+-} 15 pc, in good agreement with our distance estimate for SDSS J2249+0044AB. The space motion of SDSS J2249+0044AB shows no obvious coincidence with known young moving groups, though radial velocity and parallax measurements are necessary to refine our analysis. The unusually red near-IR colors, young age, and low masses of the binary make it an important template for studying planetary-mass objects found by direct imaging surveys.

  18. SDSS J1534+1615AB: A Novel T Dwarf Binary Found with Keck Laser Guide Star Adaptive Optics and the Potential Role of Binarity in the L/T Transition

    E-Print Network [OSTI]

    Michael C. Liu; S. K. Leggett; David A. Golimowski; Kuenley Chiu; Xiaohui Fan; T. R. Geballe; Donald P. Schneider; J. Brinkmann

    2006-05-01T23:59:59.000Z

    We have resolved the newly discovered T dwarf SDSS J1534+1615 into a 0.11'' binary using the Keck sodium laser guide star adaptive optics system. With an integrated-light spectral type of T3.5, this binary provides a new benchmark for studying the distinctive J-band brightening previously noted among early and mid-T dwarfs, using two brown dwarfs with different spectral types but having a common metallicity and age and very similar surface gravities. We estimate spectral types of T1.5+/-0.5 and T5.5+/-0.5 for the two components based on their near-IR colors, consistent with modeling the integrated-light spectrum as the blend of two components. The observed near-IR flux ratios are unique compared to all previously known substellar binaries: the component that is fainter at H and K' is brighter at J. This inversion of the near-IR fluxes is a manifestation of the J-band brightening within this individual binary system. Therefore, SDSS 1534+1615 demonstrates that the brightening can be intrinsic to ultracool photospheres (e.g., arising from cloud disruption and/or rapid increase in cloud sedimentation) and does not necessarily result from physical variations among the observed ensemble of T dwarfs (e.g., a range in masses, ages and/or metallicities). We suggest that the apparently large amplitude of the J-band brightening may be due to a high incidence of unresolved binaries and that the true amplitude of the phenomenon could be more modest. This scenario would imply that truly single objects in these spectral subclasses are relatively rare, in agreement with the small effective temperature range inferred for the L/T transition.

  19. A Search for Eclipsing Binaries in Galactic Globular Clusters

    E-Print Network [OSTI]

    Kaspar von Braun

    2003-01-22T23:59:59.000Z

    We report on the discovery and analysis of short-period (0.1 days $< P <$ 5 days), photometrically varying binary stars around and below the main-sequence turnoff of the globular clusters (GCs) NGC 3201, M10, & M12. These eclipsing binaries (EBs) may be used to determine directly the distances to GCs and constrain the Population II stellar main-sequence masses. During our search for binaries, we discovered the signature of differential reddening across the cluster fields which was especially strong for NGC 3201 and M10. We correct for this differential reddening by calculating average $E_{V-I}$ values for stars in small subregions of the field with respect to a fiducial region, which significantly improves the appearance of the GC color-magnitude diagrams (CMDs). The reddening zero point to be added to the differential value is determined by isochrone fitting. The results of our differential dereddening are presented in the form of high-resolution extinction maps. Our search for EBs returned 14 variable stars (11 EBs) in the field of NGC 3201, 3 variables (1 EB) in M10, and 2 EBs in M12. Of these variables, only one EB in NGC 3201 (a blue straggler W Ursa Majoris contact system) is a definite GC-member, based on spectroscopic observations. Another W UMa contact EB in M12 is most likely a member of M12, based on its location in the color-magnitude diagram (CMD) and its empirically calculated absolute magnitude. We present the phased lightcurves for all variables, estimate their distances and GC membership, and show their locations in the GC fields and CMDs, as well as the spectra of the NGC 3201 EBs. Finally, we discuss the implications of our results and outline future work.

  20. Wind accretion in binary stars II. Accretion rates

    E-Print Network [OSTI]

    Tom Theuns; Henri Boffin; Alain Jorissen

    1996-02-18T23:59:59.000Z

    Smoothed particle hydrodynamics (SPH) is used to estimate accretion rates of mass, linear and angular momentum in a binary system where one component undergoes mass loss through a wind. Physical parameters are chosen such as to model the alleged binary precursors of barium stars, whose chemical peculiarities are believed to result from the accretion of the wind from a companion formerly on the asymptotic giant branch (AGB). The binary system modelled consists of a 3 solar masses AGB star on the main sequence, in a 3AU circular orbit. Three-dimensional simulations are performed for gases with polytropic indices gamma=1, 1.1 and 1.5, to bracket more realistic situations that would include radiative cooling. Mass accretion rates are found to depend on resolution and we estimate typical values of 1-2% for the gamma=1.5 case and 8% for the other models. The highest resolution obtained (with 400k particles) corresponds to an accretor of linear size 16 solar radii. Despite being (in the gamma = 1.5 case) about ten times smaller than theoretical estimates based on the Bondi-Hoyle prescription, the SPH accretion rates remain large enough to explain the pollution of barium stars. Uncertainties in the current SPH rates remain however, due to the simplified treatment of the wind acceleration mechanism, as well as to the absence of any cooling prescription and to the limited numerical resolution. Angular momentum transfer leads to significant spin up of the accretor and can account for the rapid rotation of HD165141, a barium star with a young white dwarf companion and a rotation rate unusually large among K giants.

  1. Revisit on ''Ruling out chaos in compact binary systems''

    SciTech Connect (OSTI)

    Wu Xin [Department of Physics, Nanchang University, Nanchang 330031 (China); Xie Yi [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2007-12-15T23:59:59.000Z

    Full general relativity requires that chaos indicators should be invariant in various spacetime coordinate systems for a given relativistic dynamical problem. On the basis of this point, we calculate the invariant Lyapunov exponents (LEs) for one of the spinning compact binaries in the conservative second post-Newtonian (2PN) Lagrangian formulation without the dissipative effects of gravitational radiation, using the two-nearby-orbits method with projection operations and with coordinate time as an independent variable. It is found that the actual source leading to zero LEs in one paper [J. D. Schnittman and F. A. Rasio, Phys. Rev. Lett. 87, 121101 (2001)] but to positive LEs in the other [N. J. Cornish and J. Levin, Phys. Rev. Lett. 89, 179001 (2002)] does not mainly depend on rescaling, but is due to two slightly different treatments of the LEs. It takes much more CPU time to obtain the stabilizing limit values as reliable values of LEs for the former than to get the slopes (equal to LEs) of the fit lines for the latter. Due to coalescence of some of the black holes, the LEs from the former are not an adaptive indicator of chaos for comparable mass compact binaries. In this case, the invariant fast Lyapunov indicator (FLI) of two-nearby orbits, as a very sensitive tool to distinguish chaos from order, is worth recommending. As a result, we do again find chaos in the 2PN approximation through different ratios of FLIs varying with time. Chaos cannot indeed be ruled out in real binaries.

  2. Period Change of Eclipsing Binaries from the ASAS Catalog

    E-Print Network [OSTI]

    Radoslaw Poleski; Bogumil Pilecki

    2006-07-10T23:59:59.000Z

    We present a preliminary statistical analysis of a period change of eclipsing binaries from the ASAS Catalog of Variable Stars. For each contact and semidetached system brighter than 13.3$mag$ (in V) with a period shorter than 0.4 days and at least 300 observation points we have found an angular velocity $\\omega$ and its time derivative $\\frac{d\\omega}{dt}$. According to our accuracy there is no evidence that average $\\frac{d\\omega}{dt}$ differs from 0. Light curves for selected stars are presented.

  3. Plastic flow in polycrystal states in a binary mixture

    E-Print Network [OSTI]

    Toshiyuki Hamanaka; Akira Onuki

    2007-09-05T23:59:59.000Z

    Using molecular dynamics simulation we examine dynamics in sheared polycrystal states in a binary mixture containing 10% larger particles in two dimensions. We find large stress fluctuations arising from sliding motions of the particles at the grain boundaries, which occur cooperatively to release the elastic energy stored. These dynamic processes are visualized with the aid of a sixfold angle $\\alpha_j(t)$ representing the local crystal orientation and a disorder variable $D_j(t)$ representing a deviation from the hexagonal order for particle $j$.

  4. Phase Transition in a Vlasov-Boltzmann Binary Mixture

    E-Print Network [OSTI]

    R. Esposito; Y. Guo; R. Marra

    2009-04-05T23:59:59.000Z

    There are not many kinetic models where it is possible to prove bifurcation phenomena for any value of the Knudsen number. Here we consider a binary mixture over a line with collisions and long range repulsive interaction between different species. It undergoes a segregation phase transition at sufficiently low temperature. The spatially homogeneous Maxwellian equilibrium corresponding to the mixed phase, minimizing the free energy at high temperature, changes into a maximizer when the temperature goes below a critical value, while non homogeneous minimizers, corresponding to coexisting segregated phases, arise. We prove that they are dynamically stable with respect to the Vlasov-Boltzmann evolution, while the homogeneous equilibrium becomes dynamically unstable.

  5. A Flashing Binary Combined Cycle For Geothermal Power Generation | Open

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1 WindtheEnergy Information Flashing Binary Combined Cycle

  6. Mahanagdong B-Binary GEPP | 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 YouKizildere I Geothermal Pwer Plant Jump to:LandownersLuther,Jemez Pueblo Area (DOE GTP)Texas: EnergyMahanagdong AB-Binary

  7. Mak-Ban Binary 2 GEPP | 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 YouKizildere I Geothermal Pwer Plant Jump to:LandownersLuther,Jemez Pueblo Area (DOEMak-Ban / Laguna Geothermal AreaBinary

  8. Types of Reuse

    Broader source: Energy.gov [DOE]

    The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.

  9. Statistics & Gene Expression Data Analysis Note 8: Binary Regression Outcomes and classification probabilities

    E-Print Network [OSTI]

    West, Mike

    classification, validation, prognosis Binary regression models Linear regression model based on regression Standard statistical models transform from real-value to (0, 1) using a specified non-linear functionStatistics & Gene Expression Data Analysis Note 8: Binary Regression Outcomes and classification

  10. WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel

    E-Print Network [OSTI]

    Knill, Oliver

    WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel ETH-Zurich, CH-8092, Switzerland method is particularly suitable for determining the velocity laws of stellar winds. 1. WIND TOMOGRAPHY AND ABEL'S INTEGRAL Binary systems in which a compact, point-like radiation source shines through the wind

  11. SIMULATION OF STRESSES DURING CASTING OF BINARY MAGNESIUM-ALUMINUM ALLOYS M.G. Pokorny1

    E-Print Network [OSTI]

    Beckermann, Christoph

    SIMULATION OF STRESSES DURING CASTING OF BINARY MAGNESIUM-ALUMINUM ALLOYS M.G. Pokorny1 , C, Geesthacht, Germany Keywords: Magnesium Alloys, Casting, Stress Simulation Abstract A visco-plastic deformation model is used to predict thermal stresses during casting of binary Mg-Al alloys. The predictions

  12. The Binary Energy Harvesting Channel with a Unit-Sized Battery

    E-Print Network [OSTI]

    Ulukus, Sennur

    by the exogenous energy harvesting process, energy storage capacity of the battery, and the past channel inputs1 The Binary Energy Harvesting Channel with a Unit-Sized Battery Kaya Tutuncuoglu1 , Omur Ozel2 a binary energy harvesting communication channel with a finite-sized battery at the transmitter

  13. K-means Hashing: an Affinity-Preserving Quantization Method for Learning Binary Compact Codes

    E-Print Network [OSTI]

    Bernstein, Phil

    K-means Hashing: an Affinity-Preserving Quantization Method for Learning Binary Compact Codes. In this paper, we present a hashing method adopting the k-means quantization. We propose a novel Affinity-Preserving K-means algorithm which simultane- ously performs k-means clustering and learns the binary indices

  14. CRYSTALLINE SILICATE EMISSION IN THE PROTOSTELLAR BINARY SERPENS SVS 20 David R. Ciardi

    E-Print Network [OSTI]

    De Buizer, James Michael

    CRYSTALLINE SILICATE EMISSION IN THE PROTOSTELLAR BINARY SERPENS SVS 20 David R. Ciardi Michelson near 11.3 m, while SVS 20-North exhibits a shallow amorphous silicate absorption spectrum with a peak 20-S and SVS 20-N. The presence of crystalline silicate in such a young binary system indicates

  15. CRYSTALLINE SILICATE EMISSION IN THE PROTOSTELLAR BINARY SERPENS SVS 20 David R. Ciardi

    E-Print Network [OSTI]

    De Buizer, James Michael

    CRYSTALLINE SILICATE EMISSION IN THE PROTOSTELLAR BINARY SERPENS SVS 20 David R. Ciardi Michelson near 11.3 #m, while SVS 20颅North exhibits a shallow amorphous silicate absorption spectrum with a peak 20颅S and SVS 20颅N. The presence of crystalline silicate in such a young binary system indicates

  16. Testing Closed-Source Binary Device Drivers with DDT Volodymyr Kuznetsov, Vitaly Chipounov, and George Candea

    E-Print Network [OSTI]

    Candea, George

    Testing Closed-Source Binary Device Drivers with DDT Volodymyr Kuznetsov, Vitaly Chipounov (EPFL), Switzerland Abstract DDT is a system for testing closed-source binary de- vice drivers against think of it as a pesticide against device driver bugs. DDT combines virtualization with a spe- cialized

  17. VAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE FROM

    E-Print Network [OSTI]

    ) and their binary mixtures (between 348 and 393 K). The properties of supercritical carbon dioxide were determinedVAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE the vapor-liquid equilibrium of water (between 323 and 573 K), carbon dioxide (between 230 and 290 K

  18. Turbo Codes for Binary Markov Sources 1 Guang-Chong Zhu and Fady Alajaji

    E-Print Network [OSTI]

    Linder, Tam谩s

    Turbo Codes for Binary Markov Sources 1 Guang-Chong Zhu and Fady Alajaji Dept. of Mathematics@mast.queensu.ca Abstract | The reliable transmission via Turbo codes of binary stationary ergodic Markov sources over noisy channels is investigated. The #12;rst con- stituent Turbo decoder is designed to exploit the source

  19. DIVISION S-2-SOIL CHEMISTRY Acetonitrile and Acrylonitrile Sorption on Montmorillonite from Binary

    E-Print Network [OSTI]

    Sparks, Donald L.

    DIVISION S-2-SOIL CHEMISTRY Acetonitrile and Acrylonitrile Sorption on Montmorillonite from Binary of acetonitrile and acrylonitrile on K, Na, Ca, and Mg montmorillonite from binary and ternary aqueous solutions that the sorption of acetonitrile and acrylonitrile from ternary solutions on K montmorillonite was competitive

  20. Planetary Nebulae Principles & Paradigms: Binaries, Accretion, Magnetic Fields

    E-Print Network [OSTI]

    Eric G. Blackman; Jason T. Nordhaus

    2007-10-01T23:59:59.000Z

    Observations suggest that many, if not all, post AGB systems evolve through an aspherical outflow phase. Such outflows require a sufficient engine rotational energy which binaries can provide. Via common envelope evolution, binaries can directly eject equatorial outflows or produce poloidal outflows from magnetized accretion disks around the primary or secondary. We discuss how accretion driven magnetohydrodynamic outflow models all make similar predictions for the outflow power and speed and we distinguish between the launch vs. propagation regimes of such outflows. We suggest that the high velocity bipolar outflows observed in planetary nebulae (PNe) and the lower velocity but higher power bipolar outflows observed in pre-PNe (pPNe) are kinematically consistent with time dependent accretion onto a white dwarf (WD) within a depleting envelope. Since the WD primary core is always present in all post-AGB systems, accretion onto this core is potentially common. Previous work has focused on core accretion from sub-stellar companions, but low mass stellar companions may be more important, and further work is needed.

  1. FORMATION OF STABLE MAGNETARS FROM BINARY NEUTRON STAR MERGERS

    SciTech Connect (OSTI)

    Giacomazzo, Bruno [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309 (United States); Perna, Rosalba [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2013-07-10T23:59:59.000Z

    By performing fully general relativistic magnetohydrodynamic simulations of binary neutron star mergers, we investigate the possibility that the end result of the merger is a stable magnetar. In particular, we show that, for a binary composed of two equal-mass neutron stars (NSs) of gravitational mass M {approx} 1.2 M{sub Sun} and equation of state similar to Shen et al. at high densities, the merger product is a stable NS. Such NS is found to be differentially rotating and ultraspinning with spin parameter J/M{sup 2} {approx} 0.86, where J is its total angular momentum, and it is surrounded by a disk of Almost-Equal-To 0.1 M{sub Sun }. While in our global simulations the magnetic field is amplified by about two orders of magnitude, local simulations have shown that hydrodynamic instabilities and the onset of the magnetorotational instability could further increase the magnetic field strength up to magnetar levels. This leads to the interesting possibility that, for some NS mergers, a stable and magnetized NS surrounded by an accretion disk could be formed. We discuss the impact of these new results for the emission of electromagnetic counterparts of gravitational wave signals and for the central engine of short gamma-ray bursts.

  2. Theoretical X-ray Line Profiles from Colliding Wind Binaries

    E-Print Network [OSTI]

    D. B. Henley; I. R. Stevens; J. M. Pittard

    2003-06-23T23:59:59.000Z

    We present theoretical X-ray line profiles from a range of model colliding wind systems. In particular, we investigate the effects of varying the stellar mass-loss rates, the wind speeds, and the viewing orientation. We find that a wide range of theoretical line profile shapes is possible, varying with orbital inclination and phase. At or near conjunction, the lines have approximately Gaussian profiles, with small widths (HWHM ~ 0.1 v_\\infty) and definite blue- or redshifts (depending on whether the star with the weaker wind is in front or behind). When the system is viewed at quadrature, the lines are generally much broader (HWHM ~ v_\\infty), flat-topped and unshifted. Local absorption can have a major effect on the observed profiles - in systems with mass-loss rates of a few times 10^{-6} Msol/yr the lower energy lines (E wind of the primary. The orbital variation of the line widths and shifts is reduced in a low inclination binary. The extreme case is a binary with i = 0 degrees, for which we would expect no line profile variation.

  3. Simulations of black hole-neutron star binary coalescence

    E-Print Network [OSTI]

    William H. Lee

    2001-01-09T23:59:59.000Z

    We show the results of dynamical simulations of the coalescence of black hole-neutron star binaries. We use a Newtonian Smooth Particle Hydrodynamics code, and include the effects of gravitational radiation back reaction with the quadrupole approximation for point masses, and compute the gravitational radiation waveforms. We assume a polytropic equation of state determines the structure of the neutron star in equilibrium, and use an ideal gas law to follow the dynamical evolution. Three main parameters are explored: (i) The distribution of angular momentum in the system in the initial configuration, namely tidally locked systems vs. irrotational binaries; (ii) The stiffness of the equation of state through the value of the adiabatic index Gamma (ranging from Gamma=5/3 to Gamma=3); (iii) The initial mass ratio q=M(NS)/M(BH). We find that it is the value of Gamma that determines how the coalescence takes place, with immediate and complete tidal disruption for Gamma less than 2, while the core of the neutron star survives and stays in orbit around the black hole for Gamma=3. This result is largely independent of the initial mass ratio and spin configuration, and is reflected directly in the gravitational radiation signal. For a wide range of mass ratios, massive accretion disks are formed (M(disk)~0.2 solar masses), with baryon-free regions that could possibly give rise to gamma ray bursts.

  4. Photometric analysis of the overcontact binary CW Cas

    SciTech Connect (OSTI)

    Wang, J. J.; Qian, S. B.; He, J. J.; Li, L. J.; Zhao, E. G., E-mail: wjjbxw@ynao.ac.cn [National Astronomical Observatories/Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, 650011 Kunming (China)

    2014-11-01T23:59:59.000Z

    New CCD photometric observations of overcontact binary CW Cas were carried out in 2004 and 2011. In particular, the light curve obtained in 2004 shows a remarkable O'Connell effect. Compared with light curves in different observing seasons, variations were found. These variations can be explained by dark spot activities on the surface of at least one component. Using the Wilson-Devinney code with a spot model, we find that the photometric solutions confirm CW Cas is a shallow W-subtype overcontact binary with a spotted massive component. Our new determined times of minimum light together with the others published in the literature were analyzed to find a change of orbital period. From the O C curves, the period of the system shows a cyclic period change (P {sub 3} = 69.9 yr, A {sub 3} = 0.03196 days) superposed on the linear increase. The cyclic variation, if explained as the light-travel time effect, reveals the presence of a tertiary companion.

  5. Postirradiation deformation of ferritic Fe-Cr binary alloys

    SciTech Connect (OSTI)

    Hamilton, M.L.; Gelles, D.S.

    1991-06-01T23:59:59.000Z

    Six binary Fe-Cr alloys ranging from 3 to 18% chromium were irradiated in the form of miniature tensile specimens in the Fast Flux Test Facility and tested at room temperature. The irradiation conditions produced 7 to 30 dpa at 365 to 574{degrees}C. The major purpose of the experiment was to compare the behavior of these simple alloys with that of more complex commercial alloys, The tensile data obtained on these specimens at room temperature are discussed with appropriate fractographic and microstructural support. Previous studies on similar materials had revealed the presence of a feature typically exhibited in channel fractures: elongated voids were evident in shear bands of an irradiated and deformed TEM disk of a binary Fe-6Cr alloy. An additional purpose of the experiment was therefore to provide a better understanding of the potential contribution of channel fracture to deformation in ferritic alloys. No evidence for channel fracture was found, however. 14 refs., 6 figs., 2 tabs.

  6. PPl 15 The First Brown Dwarf Spectroscopic Binary

    E-Print Network [OSTI]

    Basri, G S; Basri, Gibor; Martin, Eduardo

    1999-01-01T23:59:59.000Z

    PPl 15 is the first object to have been confirmed as a brown dwarf by the lithium test (in 1995), though its inferred mass was very close to the substellar limit. It is a member of the Pleiades open cluster. Its position in a cluster color-magnitude diagram suggested that it might be binary, and preliminary indications that it is a double-lined spectroscopic binary were reported by us in 1997. Here we report on the results of a consecutive week of Keck HIRES observations of this system, which yield its orbit. It has a period of about 5.8 days, and an eccentricity of 0.4+/-0.05. The rotation of the stars is slow for this class of objects. Because the system luminosity is divided between 2 objects with a mass ratio of 0.85, this renders each of them an incontrovertible brown dwarf, with masses between 60-70 jupiters. We show that component B is a little redder than A by studying their wavelength-dependent line ratios, and that this variation is compatible with the mass ratio. We confirm that the system has lith...

  7. 3D Duo Binary Turbo Decoder Hardware Implementation

    E-Print Network [OSTI]

    Timo Lehngik-emden; Matthias Alles; Norbert Wehn

    Abstract: Each digital communication system needs channel coding to provide a certain quality of service. With the introducation of advanced channel codes like turbo codes and LDPC codes, error correcting near theoretical shannon limit became possible. Many applications require a low error floor in addition. The classical turbo code cannot meet this demand. Increasing the number of components codes, non-binary component codes or code concatenation are solutions for this problem, but come with a large complexity increase. In 2007 a new class of turbo codes, the 3D turbo code, was introduced by Berrou. The 3D turbo code provides a very good convergence and a large minimum distance at a low complexity. To the best of our knowledge this paper presents the first hardware implementation of a 3D turbo decoder. In addition we compare the implementation complexity of the 3D turbo decoder with the 8 and 16-state duo binary turbo decoder on FPGA and in 65nm ASIC technology.

  8. GeV gamma-rays and TeV neutrinos from very massive compact binary systems: The case of WR 20a

    E-Print Network [OSTI]

    W. Bednarek

    2005-07-24T23:59:59.000Z

    Massive Wolf-Rayet stars in a compact binary systems are characterised by very strong winds which collide creating a shock wave. If the wind nuclei accelerated at the shock can reach large enough energies, they suffer disintegration in collisions with soft thermal radiation from the massive stars injecting relativistic protons and neutrons. Protons collide with the matter of the wind and a fraction of neutrons colide with the massive stars producing gamma-rays and neutrinos. We calculate the gamma-rays fluxes from the inverse Compton pair cascades, initiated by primary gamma-rays and leptons produced by protons, and the neutrino fluxes produced by protons and neutrons for the example compact massive binary WR 20a. From normalization of the gamma-ray spectra to the fluxes of the EGRET sources, 2EG J1021-5835 and 2EG J1049-5847, we conclude that this massive binary can be detected by the IceCube type neutrino detector with the event rate between a few up to a few tens per km^2 per yr.

  9. Short Gamma Ray Bursts as possible electromagnetic counterpart of coalescing binary systems

    E-Print Network [OSTI]

    S. Capozziello; M. De Laurentis; I. De Martino; M. Formisano

    2010-04-27T23:59:59.000Z

    Coalescing binary systems, consisting of two collapsed objects, are among the most promising sources of high frequency gravitational waves signals detectable, in principle, by ground-based interferometers. Binary systems of Neutron Star or Black Hole/Neutron Star mergers should also give rise to short Gamma Ray Bursts, a subclass of Gamma Ray Bursts. Short-hard-Gamma Ray Bursts might thus provide a powerful way to infer the merger rate of two-collapsed object binaries. Under the hypothesis that most short Gamma Ray Bursts originate from binaries of Neutron Star or Black Hole/Neutron Star mergers, we outline here the possibility to associate short Gamma Ray Bursts as electromagnetic counterpart of coalescing binary systems.

  10. Variation of dispersion measure: evidence of geodetic precession of binary pulsars

    E-Print Network [OSTI]

    B. P. Gong

    2003-06-04T23:59:59.000Z

    Variations of dispersion measure (DM) have been observed in some binary pulsars, which can not be well explained by the propagation effects, such as turbulence of the interstellar media (ISM) between the Earth and the pulsar. This paper provides an alternative interpretation of the phenomena, the geodetic precession of the orbit plane of a binary pulsar system. The dynamic model can naturally avoid the difficulties of propagation explanations. Moreover the additional time delay represented by the DM variation of two binary pulsars can be fitted numerically, through which some interesting parameters of the binary pulsar system, i.e., the moment of inertia of pulsars can be obtained, $I_1=(2.0\\pm0.6)\\times 10^{45}$g cm$^{2}$. The elimination of the additional time delay by the dynamic effect means that ISM between the these pulsars and the Earth might also be stable, like some other binary pulsars.

  11. Identification of Owner抯 Project Value Interests

    E-Print Network [OSTI]

    Gunby, Molly Gaynell

    2011-02-22T23:59:59.000Z

    and to aid the engineering and/or construction (E&C) provider in identifying an 4 appropriate value interest response strategy. The efforts of the CII study provided the value interest, project characteristic, and survey data required to complete... execution and delivery. Berman (2006) developed the Speed2Value? Road Map, a comprehensive process designed to help organizations focus on and achieve the strategic value of a project. The process is broad enough to be used in any industry and provides...

  12. TO: FILE MEMORANDUM SUBJECT: ALTERNATE OWNER(S)

    Office of Legacy Management (LM)

    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 currentBradleyTableSelling7 AugustAFRICAN3uj: ;;I : T'ncZl'FILESUBJECT:

  13. Isothermal vapor-liquid equilibria for water + 2-aminoethanol + dimethyl sulfoxide and its constituent three binary systems

    SciTech Connect (OSTI)

    Tochigi, Katsumi; Akimoto, Kentarou; Ochi, Kenji [Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry] [Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry; Liu, Fangyhi; Kawase, Yasuhito [Nippon Refine Co., Ltd., Tokyo (Japan)] [Nippon Refine Co., Ltd., Tokyo (Japan)

    1999-05-01T23:59:59.000Z

    Isothermal vapor-liquid equilibria were measured for the ternary system water + 2-aminoethanol + dimethyl sulfoxide and its three constituent binary mixtures at 363.15 K. The apparatus used was a modified Rogalski-Malanoski equilibrium still. The experimental binary data were correlated by the NRTL equation. The ternary system was predicted using the binary NRTL parameters with good accuracy.

  14. The chromospherically active binary star EI Eridani II. Long-term Doppler imaging

    E-Print Network [OSTI]

    A. Washuettl; K. G. Strassmeier; M. Weber

    2008-11-19T23:59:59.000Z

    Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three spectroscopic lines for 32 epochs, 28 of which are independent of each other. Various parameters are extracted from our Doppler maps: average temperature, fractional spottedness, and longitudinal and latitudinal spot-occurrence functions. We find that none of these parameters show a distinct variation nor a correlation with the proposed activity cycle as seen from photometric long-term observations. This suggests that the photometric brightness cycle may not necessarily be due to just a cool spot cycle. The general morphology of the spot pattern remains persistent over the whole period of 11 years. A large cap-like polar spot was recovered from all our images. A high degree of variable activity was noticed near latitudes of approx. 60-70 degrees where the appendages of the polar spot emerged and dissolved.

  15. On the spin period distribution in Be/X-ray binaries

    SciTech Connect (OSTI)

    Cheng, Z.-Q.; Shao, Y.; Li, X.-D., E-mail: lixd@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2014-05-10T23:59:59.000Z

    There is a remarkable correlation between the spin periods of the accreting neutron stars (NSs) in Be/X-ray binaries (BeXBs) and their orbital periods. Recently, Knigge et al. showed that the distribution of the spin periods contains two distinct subpopulations peaked at ?10 s and ?200 s, respectively, and suggested that they may be related to two types of supernovae for the formation of the NSs, i.e., core-collapse and electron-capture supernovae. Here we propose that the bimodal spin period distribution is likely to be ascribed to different accretion modes of the NSs in BeXBs. When the NS tends to capture material from the warped, outer part of the Be star disk and experiences giant outbursts, a radiatively cooling dominated disk is formed around the NS, which spins up the NS and is responsible for the short-period subpopulation. In BeXBs that are dominated by normal outbursts or are persistent, the accretion flow is advection-dominated or quasi-spherical. The spin-up process is accordingly inefficient, leading to longer periods of the neuron stars. The potential relation between the subpopulations and the supernova mechanism is also discussed.

  16. Long-term evolution of double white dwarf binaries accreting through direct impact

    E-Print Network [OSTI]

    Kremer, Kyle; Kalogera, Vassiliki

    2015-01-01T23:59:59.000Z

    We calculate the long-term evolution of angular momentum in double white dwarf binaries undergoing direct impact accretion over a broad range of parameter space. We allow the rotation rate of both components to vary, and account for the exchange of angular momentum between the spins of the white dwarfs and the orbit, while conserving the total angular momentum. We include gravitational, tidal, and mass transfer effects in the orbital evolution, and allow the Roche radius of the donor star to vary with both the stellar mass and the rotation rate. We examine the long-term stability of these systems, focusing in particular on those systems that may be progenitors of AM CVn or Type Ia Supernovae. We find that our analysis yields an increase in the predicted number of stable systems compared to that in previous studies. Additionally, we find that by properly accounting for the effects of asynchronism between the donor and the orbit on the Roche-lobe size, we eliminate oscillations in the orbital parameters which a...

  17. GeV-TeV gamma-ray light curves expected in the IC electron-positron pair cascade model for massive binaries: Application to LS 5039

    E-Print Network [OSTI]

    W. Bednarek

    2006-11-09T23:59:59.000Z

    TeV gamma-ray emission from two massive binaries of the microquasar type, LS 5039 and LS I +61$^{\\rm o}$ 303, show clear variability with their orbital periods. Our purpose is to calculate the GeV and TeV $\\gamma$-ray light curves from the massive binary LS 5039 which are expected in the specific Inverse Compton $e^\\pm$ pair cascade model. This model successfully predicted the basic features of the high energy $\\gamma$-ray emission from LS 5039 and LS I +61 303. In the calculations we apply the Monte Carlo code which follows the IC $e^\\pm$ pair cascade in the anisotropic radiation of the massive star. The $\\gamma$-ray light curves and spectra are obtained for different parameters of the acceleration scenario and the inclination angles of the binary system. It is found that the GeV and TeV $\\gamma$-ray light curves should be anti-correlated. This feature can be tested in the near future by the simultaneous observations of LS 5039 with the AGILE and GLAST telescopes in GeV energies and the Cherenkov telescopes in the TeV energies. Considered model also predicts a broad maximum in the TeV $\\gamma$-ray light curve between the phases $\\sim 0.4-0.8$ consistently with the observations of LS 5039 by the HESS telescopes. Moreover, we predict additional dip in the TeV light curve for large inclination angles $\\sim 60^{\\rm o}$. This feature could serve as a diagnostic for independent measuring of the inclination angle of this binary system indicating also on the presence of a neutron star in LS 5039.

  18. TWO WIDE PLANETARY-MASS COMPANIONS TO SOLAR-TYPE STARS IN UPPER SCORPIUS

    SciTech Connect (OSTI)

    Ireland, M. J. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Kraus, A. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Martinache, F. [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States); Law, N. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto M5S 3H4, Ontario (Canada); Hillenbrand, L. A. [Department of Astrophysics, California Institute of Technology, MC 105-24, Pasadena, CA 91125 (United States)

    2011-01-10T23:59:59.000Z

    At wide separations, planetary-mass and brown dwarf companions to solar-type stars occupy a curious region of parameter space not obviously linked to binary star formation or solar system scale planet formation. These companions provide insight into the extreme case of companion formation (either binary or planetary), and due to their relative ease of observation when compared to close companions, they offer a useful template for our expectations of more typical planets. We present the results from an adaptive optics imaging survey for wide ({approx}50-500 AU) companions to solar-type stars in Upper Scorpius. We report one new discovery of a {approx}14 M{sub J} companion around GSC 06214-00210and confirm that the candidate planetary-mass companion 1RXS J160929.1-210524 detected by Lafreniere et al. is in fact comoving with its primary star. In our survey, these two detections correspond to {approx}4% of solar-type stars having companions in the 6-20 M{sub J} mass and {approx}200-500 AU separation range. This figure is higher than would be expected if brown dwarfs and planetary-mass companions were drawn from an extrapolation of the binary mass function. Finally, we discuss implications for the formation of these objects.

  19. Dispute Resolution Process Utility Owner

    E-Print Network [OSTI]

    Minnesota, University of

    State One Call (GSOC) for "Design Call" Provide "as-builts", marked plans or field locates MnDOT Utility? Underground Utility? Contact Minnesota Office of Pipeline Safety Minnesota Office of Pipeline Safety Step 1 - Utility Identification for Construction Investigate and take appropriate action up to and including

  20. Institutional owners and competitive rivalry

    E-Print Network [OSTI]

    Connelly, Brian Lawrence

    2008-10-10T23:59:59.000Z

    factors that make firms increasingly aware of competitive behavior (e.g., TMT heterogeneity and This dissertation follows the style of the Academy of Management Journal. 2 multimarket competition) and increasingly capable of initiating...

  1. Binary Black Holes in Quasi-Stationary Circular Orbits

    E-Print Network [OSTI]

    Brian D. Baker

    2002-05-18T23:59:59.000Z

    We propose a method of determining solutions to the constraint equations of General Relativity approximately describing binary black holes in quasi-stationary circular orbits. Black holes with arbitrary linear momenta are constructed in the manner suggested by Brandt and Brugmann. The quasi-stationary circular orbits are determined by local minima in the ADM mass in a manner similar to Baumgarte and Cook; however, rather than fixing the area of the apparent horizon, we fix the value of the bare masses of the holes. We numerically generate an evolutionary sequence of quasi-stationary circular orbits up to and including the innermost stable circular orbit. We compare our results with post-Newtonian expectations as well as the results of Cook and Baumgarte. We also generate additional numerical results describing the dynamics of the geometry due to the emission of gravitational radiation.

  2. Stability of prograde and retrograde planets in circular binary systems

    E-Print Network [OSTI]

    M. H. M. Morais; C. A. Giuppone

    2012-06-22T23:59:59.000Z

    We investigate the stability of prograde versus retrograde planets in circular binary systems using numerical simulations. We show that retrograde planets are stable up to distances closer to the perturber than prograde planets. We develop an analytical model to compute the prograde and retrograde mean motion resonances' locations and separatrices. We show that instability is due to single resonance forcing, or caused by nearby resonances' overlap. We validate our results regarding the role of single resonances and resonances' overlap on orbit stability, by computing surfaces of section of the CR3BP. We conclude that the observed enhanced stability of retrograde planets with respect to prograde planets is due to essential differences between the phase-space topology of retrograde versus prograde resonances (at p/q mean motion ratio, prograde resonance is of order p - q while retrograde resonance is of order p + q).

  3. Low velocity ion stopping in binary ionic mixtures

    SciTech Connect (OSTI)

    Tashev, Bekbolat; Baimbetov, Fazylkhan [Department of Physics, Kazakh National University, Tole Bi 96, Almaty 480012 (Kazakhstan); Deutsch, Claude [LPGP (UMR-CNRS 8578), Universite Paris XI, 91405 Orsay (France); Fromy, Patrice [Direction de l'Informatique, Universite Paris XI, 91405 Orsay (France)

    2008-10-15T23:59:59.000Z

    Attention is focused on the low ion velocity stopping mechanisms in multicomponent and dense target plasmas built of quasiclassical electron fluids neutralizing binary ionic mixtures, such as, deuterium-tritium of current fusion interest, proton-heliumlike iron in the solar interior or proton-helium ions considered in planetology, as well as other mixtures of fiducial concern in the heavy ion beam production of warm dense matter at Bragg peak conditions. The target plasma is taken in a multicomponent dielectric formulation a la Fried-Conte. The occurrence of projectile ion velocities (so-called critical) for which target electron slowing down equals that of given target ion components is also considered. The corresponding multiquadrature computations, albeit rather heavy, can be monitored analytical through a very compact code operating a PC cluster. Slowing down results are systematically scanned with respect to target temperature and electron density, as well as ion composition.

  4. The chromospherically active binary star EI Eridani I. Absolute dimensions

    E-Print Network [OSTI]

    A. Washuettl; K. G. Strassmeier; T. Granzer; M. Weber; K. Ol醜

    2008-09-04T23:59:59.000Z

    We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the barycentric velocity. A possible third-body orbit with a period of approximately 19 years is presented. Absolute parameters are determined in combination with the Hipparcos parallax. EI Eri's inclination angle of the rotational axis is confined to 56.0 plus/minus 4.5 degrees, its luminosity class IV is confirmed by its radius of 2.37 plus/minus 0.12 R_Sun. A comparison to theoretical stellar evolutionary tracks suggests a mass of 1.09 plus/minus 0.05 M_Sun and an age of approximately 6.15 Gyr. The present investigation is the basis of our long-term Doppler imaging study of its stellar surface.

  5. Heating mechanism affects equipartition in a binary granular system

    E-Print Network [OSTI]

    Hong-Qiang Wang; Narayanan Menon

    2008-03-08T23:59:59.000Z

    Two species of particles in a binary granular system typically do not have the same mean kinetic energy, in contrast to the equipartition of energy required in equilibrium. We investigate the role of the heating mechanism in determining the extent of this non-equipartition of kinetic energy. In most experiments, different species of particle are unequally heated at the boundaries. We show by event-driven simulations that this differential heating at the boundary influences the level of non-equipartition even in the bulk of the system. This conclusion is fortified by studying a numerical model and a solvable stochastic model without spatial degrees of freedom. In both cases, even in the limit where heating events are rare compared to collisions, the effect of the heating mechanism persists.

  6. AA Dor - An Eclipsing sdOB - Brown Dwarf Binary

    E-Print Network [OSTI]

    Thomas Rauch

    2003-11-25T23:59:59.000Z

    AA Dor is an eclipsing, close, post common-envelope binary consisting of a sdOB primary star and an unseen secondary with an extraordinary small mass - formally a brown dwarf. The brown dwarf may have been a former planet which survived a common envelope phase and has even gained mass. A recent determination of the components' masses from results of NLTE spectral analysis and subsequent comparison to evolutionary tracks shows a discrepancy to masses derived from radial-velocity and the eclipse curves. Phase-resolved high-resolution and high-SN spectroscopy was carried out in order to investigate on this problem. We present results of a NLTE spectral analysis of the primary, an analysis of its orbital parameters, and discuss possible evolutionary scenarios.

  7. Beowawe Bottoming Binary Unit - Final Technical Report for EE0002856

    SciTech Connect (OSTI)

    McDonald, Dale Edward

    2013-02-12T23:59:59.000Z

    This binary plant is the first high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a butane based cycle are not necessary. The unit is modularized, meaning that the unit抯 individual skids were assembled in another location and were shipped via truck to the plant site. This project proves the technical feasibility of using low temperature brine The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy for Nevada, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  8. Optimal Designs for 2^k Factorial Experiments with Binary Response

    E-Print Network [OSTI]

    Yang, Jie; Majumdar, Dibyen

    2011-01-01T23:59:59.000Z

    We consider the problem of obtaining locally D-optimal designs for factorial experiments with binary response and $k$ qualitative factors at two levels each. Yang, Mandal and Majumdar (2011) considered this problem for $2^2$ factorial experiments. In this paper, we generalize the results for $2^k$ designs and explore in new directions. We obtain a characterization for a design to be locally D-optimal. Based on this characterization, we develop efficient numerical techniques to search for locally D-optimal designs. We also investigate the properties of fractional factorial designs and study the robustness of locally D-optimal designs. Using prior distribution on the parameters, we investigate EW D-optimal designs, that are designs which maximize the determinant of the expected information matrix. It turns out that these designs are much easier to find and still highly efficient compared to Bayesian D-optimal designs, as well as quite robust.

  9. Absolute properties of the eclipsing binary star IM Persei

    SciTech Connect (OSTI)

    Lacy, Claud H. Sandberg [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Torres, Guillermo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fekel, Francis C.; Muterspaugh, Matthew W. [Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 (United States); Southworth, John, E-mail: clacy@uark.edu, E-mail: gtorres@cfa.harvard.edu, E-mail: fekel@evans.tsuniv.edu, E-mail: matthew1@coe.tsuniv.edu, E-mail: astro.js@keele.ac.uk [Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom)

    2015-01-01T23:59:59.000Z

    IM Per is a detached A7 eccentric eclipsing binary star. We have obtained extensive measurements of the light curve (28,225 differential magnitude observations) and radial velocity curve (81 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.7831 0.0094 and 1.7741 0.0097 solar masses, and radii of 2.409 0.018 and 2.366 0.017 solar radii. The orbital period is 2.25422694(15) days and the eccentricity is 0.0473(26). A faint third component was detected in the analysis of the light curves, and also directly observed in the spectra. The observed rate of apsidal motion is consistent with theory (U = 151.4 8.4 year). We determine a distance to the system of 566 46 pc.

  10. Resurvey of order and chaos in spinning compact binaries

    SciTech Connect (OSTI)

    Wu Xin [Department of Physics, Nanchang University, Nanchang 330031 (China); Xie Yi [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2008-05-15T23:59:59.000Z

    This paper is mainly devoted to applying the invariant, fast, Lyapunov indicator to clarify some doubt regarding the apparently conflicting results of chaos in spinning compact binaries at the second-order post-Newtonian approximation of general relativity from previous literatures. It is shown with a number of examples that no single physical parameter or initial condition can be described as responsible for causing chaos, but a complicated combination of all parameters and initial conditions is responsible. In other words, a universal rule for the dependence of chaos on each parameter or initial condition cannot be found in general. Chaos does not depend only on the mass ratio, and the maximal spins do not necessarily bring the strongest effect of chaos. Additionally, chaos does not always become drastic when the initial spin vectors are nearly perpendicular to the orbital plane, and the alignment of spins cannot trigger chaos by itself.

  11. The precession of eccentric discs in close binaries

    E-Print Network [OSTI]

    James R. Murray

    1999-11-25T23:59:59.000Z

    We consider the precession rates of eccentric discs in close binaries, and compare theoretical predictions with the results of numerical disc simulations and with observed superhump periods. A simple dynamical model for precession is found to be inadequate. For mass ratios less than approximately 1/4 a linear dynamical model does provide an upper limit for disc precession rates. Theory suggests that pressure forces have a significant retrograde impact upon the precession rate (Lubow 1992). We find that the disc precession rates for three systems with accurately known mass ratios are significantly slower than predicted by the dynamical theory, and we attribute the difference to pressure forces. By assuming that pressure forces of similar magnitude occur in all superhumping systems, we obtain an improved fit to superhump observations.

  12. Merger of white dwarf-neutron star binaries: Prelude to hydrodynamic simulations in general relativity

    SciTech Connect (OSTI)

    Paschalidis, Vasileios [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); MacLeod, Morgan [Department of Physics and Astronomy, Bowdoin College, Brunswick, Maine 04011 (United States); Baumgarte, Thomas W. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Physics and Astronomy, Bowdoin College, Brunswick, Maine 04011 (United States); Shapiro, Stuart L. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Astronomy and NCSA, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2009-07-15T23:59:59.000Z

    White dwarf-neutron star binaries generate detectable gravitational radiation. We construct Newtonian equilibrium models of corotational white dwarf-neutron star (WDNS) binaries in circular orbit and find that these models terminate at the Roche limit. At this point the binary will undergo either stable mass transfer (SMT) and evolve on a secular time scale, or unstable mass transfer (UMT), which results in the tidal disruption of the WD. The path a given binary will follow depends primarily on its mass ratio. We analyze the fate of known WDNS binaries and use population synthesis results to estimate the number of LISA-resolved galactic binaries that will undergo either SMT or UMT. We model the quasistationary SMT epoch by solving a set of simple ordinary differential equations and compute the corresponding gravitational waveforms. Finally, we discuss in general terms the possible fate of binaries that undergo UMT and construct approximate Newtonian equilibrium configurations of merged WDNS remnants. We use these configurations to assess plausible outcomes of our future, fully relativistic simulations of these systems. If sufficient WD debris lands on the NS, the remnant may collapse, whereby the gravitational waves from the inspiral, merger, and collapse phases will sweep from LISA through LIGO frequency bands. If the debris forms a disk about the NS, it may fragment and form planets.

  13. Typed Self-Optimization

    E-Print Network [OSTI]

    Brown, Matt

    2013-01-01T23:59:59.000Z

    type T y[O]. The operator IsIs is self-applicative, in thatargument t is any of Is[O] or IsIs, and otherwise behavesproof constant introduced by IsIs proves that the type of t

  14. Isothermal vapor-liquid equilibria for benzene + cyclohexane + 1-propanol and for three constituent binary systems

    SciTech Connect (OSTI)

    Kurihara, Kiyofumi; Uchiyama, Masanori; Kojima, Kazuo [Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry] [Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry

    1997-01-01T23:59:59.000Z

    Isothermal vapor-liquid equilibria were measured for the ternary system of benzene + cyclohexane + 1-propanol and its constituent binary systems of benzene + cyclohexane, cyclohexane + 1-propanol, and benzene + 1-propanol at 323.15 and 333.15 K, using the apparatus proposed in a previous study. The experimental binary data were correlated using the NRTL equation. The ternary system was predicted using the binary NRTL parameters. The average absolute percent deviations between the predicted and experimental ternary total pressures are 0.5% at 323.15 K and 0.4% at 333.15 K.

  15. Your Guide to Diabetes: Type 1 and Type 2

    E-Print Network [OSTI]

    Rau, Don C.

    Your Guide to Diabetes: Type 1 and Type 2 National Diabetes Information Clearinghouse #12;#12;Your Guide to Diabetes: Type 1 and Type 2 #12;#12;Contents Learn about Diabetes ............................................................ 1 What is diabetes? .............................................................. 2 What

  16. UPS, the UPS brandmark and the color brown are trademarks that are used with permission by the owner, United Parcel Service of America, Inc. All rights reserved. You may type directly into this form

    E-Print Network [OSTI]

    Jones, Michelle

    UPS, the UPS brandmark and the color brown are trademarks that are used with permission VALUE Post / Zip Post / Zip UPS NEXT DAY AIR Most deliveries made by 10:30 a.m. UPS GROUND Delivery in 15 business days (in-state deliveries usually arrive next day) UPS WORLDWIDE SAVERSM Int'l Service

  17. Classical novae and type I X-ray bursts: Challenges for the 21st century

    SciTech Connect (OSTI)

    Parikh, A., E-mail: anuj.r.parikh@upc.edu; Jos, J., E-mail: jordi.jose@upc.edu; Sala, G., E-mail: gloria.sala@upc.edu [Departament de F韘ica i Enginyeria Nuclear, Universitat Polit鑓nica de Catalunya (EUETIB), E-08036 Barcelona (Spain); Institut d扙studis Espacials de Catalunya (IEEC), E-08034 Barcelona (Spain)

    2014-04-15T23:59:59.000Z

    Classical nova explosions and type I X-ray bursts are the most frequent types of thermonuclear stellar explosions in the Galaxy. Both phenomena arise from thermonuclear ignition in the envelopes of accreting compact objects in close binary star systems. Detailed observations of these events have stimulated numerous studies in theoretical astrophysics and experimental nuclear physics. We discuss observational features of these phenomena and theoretical efforts to better understand the energy production and nucleosynthesis in these explosions. We also examine and summarize studies directed at identifying nuclear physics quantities with uncertainties that significantly affect model predictions.

  18. Transformations in Massive Binary Stars: CRA Colloquium, Jan. 15, 2009 1 Mass and Angular Momentum

    E-Print Network [OSTI]

    Gies, Douglas R.

    over lives Progenitors of the Long Gamma Ray Bursts Binary Star Surveys Early Stages of Interacting, 2009 3 Progenitors of Long Gamma Ray Bursts Collapsar model (Woosley 1993): core of a massive, fast

  19. Linking electromagnetic and gravitational radiation in coalescing binary neutron stars Carlos Palenzuela1

    E-Print Network [OSTI]

    Lumsdaine, Andrew

    a fundamental role in the production of gamma ray bursts. These compact binary systems are also among the most model of short, hard gamma ray bursts (SGRBs) (see e.g. [2] for a review). This model envisions

  20. THE YOUNGEST KNOWN X-RAY BINARY: CIRCINUS X-1 AND ITS NATAL SUPERNOVA REMNANT

    E-Print Network [OSTI]

    Heinz, S.

    Because supernova remnants are short-lived, studies of neutron star X-ray binaries within supernova remnants probe the earliest stages in the life of accreting neutron stars. However, such objects are exceedingly rare: ...

  1. X-ray spectroscopy of neutron star low-mass X-ray binaries

    E-Print Network [OSTI]

    Krauss, Miriam Ilana

    2007-01-01T23:59:59.000Z

    In this thesis, I present work spanning a variety of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. ...

  2. High speed simulation of microprocessor systems using LTU dynamic binary translation

    E-Print Network [OSTI]

    Jones, Daniel

    2010-01-01T23:59:59.000Z

    This thesis presents new simulation techniques designed to speed up the simulation of microprocessor systems. The advanced simulation techniques may be applied to the simulator class which employs dynamic binary translation ...

  3. Radial Velocity Curves of Ellipsoidal Red Giant Binaries in the Large Magellanic Cloud

    E-Print Network [OSTI]

    Nie, J D

    2015-01-01T23:59:59.000Z

    Ellipsoidal red giant binaries are close binary systems where an unseen, relatively close companion distorts the red giant, leading to light variations as the red giant moves around its orbit. These binaries are likely to be the immediate evolutionary precursors of close binary planetary nebula and post-asymptotic giant branch and post-red giant branch stars. Due to the MACHO and OGLE photometric monitoring projects, the light variability nature of these ellipsoidal variables has been well studied. However, due to the lack of radial velocity curves, the nature of their masses, separations, and other orbital details has so far remained largely unknown. In order to improve this situation, we have carried out spectral monitoring observations of a large sample of 80 ellipsoidal variables in the Large Magellanic Cloud and we have derived radial velocity curves. At least 12 radial velocity points with good quality were obtained for most of the ellipsoidal variables. The radial velocity data are provided with this p...

  4. Observational and evolutionary studies of neutron star X-ray binaries

    E-Print Network [OSTI]

    Lin, Jinrong, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    In this thesis, we present our observational and evolutionary studies of neutron stars in X-ray binary systems. A variety of topics are discussed, which are all related by a single scientific theme, namely, helping to set ...

  5. Construction and characterization of a peach binary bacterial artificial chromosome library

    E-Print Network [OSTI]

    Wakefield, Laura

    2002-01-01T23:59:59.000Z

    Peach [Prunus persica (L.) Batch] has been proposed as a model organism for woody perennials. To facilitate genomic research in peach, a binary bacterial artificial chromosome (BIBAC) library of var. Texking was constructed using a plant...

  6. Search for gravitational waves from binary black hole inspiral, merger and ringdown

    E-Print Network [OSTI]

    The LIGO Scientific Collaboration; the Virgo Collaboration; J. Abadie; B. P. Abbott; R. Abbott; M. Abernathy; T. Accadia; F. Acernese; C. Adams; R. Adhikari; P. Ajith; B. Allen; G. S. Allen; E. Amador Ceron; R. S. Amin; S. B. Anderson; W. G. Anderson; F. Antonucci; M. A. Arain; M. C. Araya; M. Aronsson; Y. Aso; S. M. Aston; P. Astone; D. Atkinson; P. Aufmuth; C. Aulbert; S. Babak; P. Baker; G. Ballardin; T. Ballinger; S. Ballmer; D. Barker; S. Barnum; F. Barone; B. Barr; P. Barriga; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; M. Bastarrika; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. G. Beker; A. Belletoile; M. Benacquista; A. Bertolini; J. Betzwieser; N. Beveridge; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Birindelli; R. Biswas; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; B. Bland; M. Blom; C. Boccara; O. Bock; T. P. Bodiya; R. Bondarescu; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; B. Bouhou; M. Boyle; S. Braccini; C. Bradaschia; P. R. Brady; V. B. Braginsky; J. E. Brau; J. Breyer; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; R. Budzy?ski; T. Bulik; H. J. Bulten; A. Buonanno; J. Burguet-Castell; O. Burmeister; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Cain; E. Calloni; J. B. Camp; E. Campagna; P. Campsie; J. Cannizzo; K. Cannon; B. Canuel; J. Cao; C. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavaglia`; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; O. Chaibi; T. Chalermsongsak; E. Chalkley; P. Charlton; E. Chassande-Mottin; S. Chelkowski; Y. Chen; A. Chincarini; N. Christensen; S. S. Y. Chua; C. T. Y. Chung; D. Clark; J. Clark; J. H. Clayton; F. Cleva; E. Coccia; C. N. Colacino; J. Colas; A. Colla; M. Colombini; R. Conte; D. Cook; T. R. Corbitt; N. Cornish; A. Corsi; C. A. Costa; J. -P. Coulon; D. M. Coward; D. C. Coyne; J. D. E. Creighton; T. D. Creighton; A. M. Cruise; R. M. Culter; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; S. L. Danilishin; R. Dannenberg; S. D'Antonio; K. Danzmann; K. Das; V. Dattilo; B. Daudert; M. Davier; G. Davies; A. Davis; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; D. DeBra; G. Debreczeni; J. Degallaix; M. del Prete; V. Dergachev; R. DeRosa; R. DeSalvo; P. Devanka; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; M. Di Paolo Emilio; A. Di Virgilio; M. D韆z; A. Dietz; F. Donovan; K. L. Dooley; E. E. Doomes; S. Dorsher; E. S. D. Douglas; M. Drago; R. W. P. Drever; J. C. Driggers; J. Dueck; J. -C. Dumas; T. Eberle; M. Edgar; M. Edwards; A. Effler; P. Ehrens; G. Ely; R. Engel; T. Etzel; M. Evans; T. Evans; V. Fafone; S. Fairhurst; Y. Fan; B. F. Farr; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Fidecaro; L. S. Finn; I. Fiori; R. Flaminio; M. Flanigan; K. Flasch; S. Foley; C. Forrest; E. Forsi; L. A. Forte; N. Fotopoulos; J. -D. Fournier; J. Franc; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; D. Friedrich; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; M. Galimberti; L. Gammaitoni; J. A. Garofoli; F. Garufi; M. E. G醩p醨; G. Gemme; E. Genin; A. Gennai; I. Gholami; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; C. Gill; E. Goetz; L. M. Goggin; G. Gonz醠ez; M. L. Gorodetsky; S. Go遧er; R. Gouaty; C. Graef; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Greverie; R. Grosso; H. Grote; S. Grunewald; G. M. Guidi; E. K. Gustafson; R. Gustafson; B. Hage; P. Hall; J. M. Hallam; D. Hammer; G. Hammond; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; K. Haughian; K. Hayama; J. -F. Hayau; T. Hayler; J. Heefner; H. Heitmann; P. Hello; I. S. Heng; A. W. Heptonstall; M. Hewitson; S. Hild; E. Hirose; D. Hoak; K. A. Hodge; K. Holt; D. J. Hosken; J. Hough; E. J. Howell; D. Hoyland; D. Huet; B. Hughey; S. Husa; S. H. Huttner; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; P. Jaranowski; W. W. Johnson; D. I. Jones; G. Jones; R. Jones; L. Ju; P. Kalmus; V. Kalogera; S. Kandhasamy; J. B. Kanner; E. Katsavounidis; K. Kawabe; S. Kawamura; F. Kawazoe; W. Kells; D. G. Keppel; A. Khalaidovski; F. Y. Khalili; E. A. Khazanov; H. Kim; P. J. King; D. L. Kinzel; J. S. Kissel; S. Klimenko; V. Kondrashov; R. Kopparapu; S. Koranda; I. Kowalska; D. Kozak; T. Krause; V. Kringel; S. Krishnamurthy; B. Krishnan; A. Kr髄ak; G. Kuehn; J. Kullman; R. Kumar; P. Kwee; M. Landry; M. Lang; B. Lantz; N. Lastzka; A. Lazzarini; P. Leaci; J. Leong; I. Leonor; N. Leroy; N. Letendre; J. Li; T. G. F. Li; N. Liguori; H. Lin; P. E. Lindquist; N. A. Lockerbie; D. Lodhia; M. Lorenzini; V. Loriette; M. Lormand; G. Losurdo; P. Lu; J. Luan; M. Lubinski; A. Lucianetti; H. L點k; A. D. Lundgren; B. Machenschalk; M. MacInnis; M. Mageswaran; K. Mailand; E. Majorana

    2011-02-18T23:59:59.000Z

    We present the first modeled search for gravitational waves using the complete binary black hole gravitational waveform from inspiral through the merger and ringdown for binaries with negligible component spin. We searched approximately 2 years of LIGO data taken between November 2005 and September 2007 for systems with component masses of 1-99 solar masses and total masses of 25-100 solar masses. We did not detect any plausible gravitational-wave signals but we do place upper limits on the merger rate of binary black holes as a function of the component masses in this range. We constrain the rate of mergers for binary black hole systems with component masses between 19 and 28 solar masses and negligible spin to be no more than 2.0 per Mpc^3 per Myr at 90% confidence.

  7. On the Kinematics of Solar Mirrors Using Massively Parallel Binary Actuation

    E-Print Network [OSTI]

    Dubowsky, Steven

    Precision mirrors are required for effective solar energy collectors. Manufacturing such mirrors and making them robust to disturbances such as thermal gradients is expensive. In this paper, the use of parallel binary ...

  8. Synthesis and characterization of patterned surfaces and catalytically relevant binary nanocrystalline intermetallic compounds

    E-Print Network [OSTI]

    Cable, Robert E.

    2009-05-15T23:59:59.000Z

    -metallics are not yet matured. In response to this deficiency, we have developed several solution-based methods to synthesize nanocrystalline binary alloy and intermetallic compounds. This dissertation describes the processes we have developed, as well as our...

  9. Synthesis and characterization of patterned surfaces and catalytically relevant binary nanocrystalline intermetallic compounds

    E-Print Network [OSTI]

    Cable, Robert E.

    2008-10-10T23:59:59.000Z

    -metallics are not yet matured. In response to this deficiency, we have developed several solution-based methods to synthesize nanocrystalline binary alloy and intermetallic compounds. This dissertation describes the processes we have developed, as well as our...

  10. On the rarity of x-ray binaries with Wolf-Rayet donors

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

    Linden, T; Valsecchi, F; Kalogera, V

    2012-03-06T23:59:59.000Z

    The paucity of High mass X-Ray binaries (HMXB) consisting of a neutron star (NS) accretor and Wolf-Rayet (WR) donor has long been at odds with expectations from population synthesis studies indicating that these systems should survive as the evolved offspring of the observed HMXB population. This tension is particularly troubling in light of recent observations uncovering a preponderance of HMXBs containing loosely bound Be donors which would be expected to naturally evolve into WR-HMXBs. Reconciling the unexpectedly large population of Be-HMXBs with the lack of observed WR-HMXB sources thus serves to isolate the dynamics of CE physics from other binary evolution parameters. Here, we find that binary mergers during CE events must be common in order to resolve tension between these observed populations. Furthermore, future observations which better constrain the background population of loosely bound O/B-NS binaries are likely to place significant constraints on the efficiency of CE removal.

  11. accreting low-mass binary: Topics by E-print Network

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

    in post-accretion Low-Mass X-ray Binaries: A universal model for short-hard Gamma-Ray Bursts CERN Preprints Summary: We show that several features reminiscent of short-hard...

  12. adc x-ray binary: Topics by E-print Network

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

    systems. Sudip Bhattacharyya 2010-02-24 17 X-ray Transients from X-ray Binaries to Gamma Ray Bursts CERN Preprints Summary: We discuss three classes of x-ray transients to...

  13. Parameter estimation for compact binary coalescence signals with the first generation gravitational-wave detector network

    E-Print Network [OSTI]

    Barsotti, Lisa

    Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus ...

  14. Post-Newtonian Theory for Precision Doppler Measurements of Binary Star Orbits

    E-Print Network [OSTI]

    Kopeikin, S M

    1999-01-01T23:59:59.000Z

    The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. Seven appropriate reference frames are introduced and then we apply successive Lorentz transformations and the relativistic equation of light propagation to establish the exact treatment of Doppler effect in binary systems, both in special and general relativity theories. As a result, the Doppler shift is a sum of (1) linear in $c^{-1}$ terms, which include the ordinary Doppler effect and its variation due to the secular radial acceleration of the binary with respect to observer; (2) terms proportional to $c^{-2}$, which include the contributions from the quadratic Doppler effect caused by the relative motion of binary star with respect to the Solar system, motion of the particle emitting light and diurnal rotational motion of observer, orbital motion of the star around the binar...

  15. Fejer-type inequalities

    E-Print Network [OSTI]

    Mitroi, F C

    2011-01-01T23:59:59.000Z

    The aim of this paper is to present some new Fejer-type results for convex functions. Improvements of Young's inequality (the arithmetic-geometric mean inequality) and other applications to special means are pointed as well.

  16. Document Type: Subject Terms

    E-Print Network [OSTI]

    Major, Arkady

    Title: Authors: Source: Document Type: Subject Terms: Abstract: Full Text Word Count: ISSN at creating team results. In fact, it's priceless. Managers in Western corporations have received a lifetime

  17. Binary and ternary gas mixtures for use in glow discharge closing switches

    DOE Patents [OSTI]

    Hunter, Scott R. (Oak Ridge, TN); Christophorou, Loucas G. (Oak Ridge, TN)

    1990-01-01T23:59:59.000Z

    Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue of the combined physio-electric properties of the mixture components.

  18. Post-Newtonian Theory for Precision Doppler Measurements of Binary Star Orbits

    E-Print Network [OSTI]

    S. M. Kopeikin; L. M. Ozernoy

    1999-01-31T23:59:59.000Z

    The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. We apply successive Lorentz transformations and the relativistic equation of light propagation to establish the exact treatment of Doppler effect in binary systems both in special and general relativity theories. As a result, the Doppler shift is a sum of (1) linear in $c^{-1}$ terms, which include the ordinary Doppler effect and its variation due to the secular radial acceleration of the binary with respect to observer; (2) terms proportional to $c^{-2}$, which include the contributions from the quadratic Doppler effect caused by the relative motion of binary star with respect to the Solar system, motion of the particle emitting light and diurnal rotational motion of observer, orbital motion of the star around the binary's barycenter, and orbital motion of the Earth; and (3) terms proportional to $c^{-2}$, which include the contributions from redshifts due to gravitational fields of the star, star's companion, Galaxy, Solar system, and the Earth. After parameterization of the binary's orbit we find that the presence of periodically changing terms in the Doppler schift enables us disentangling different terms and measuring, along with the well known Keplerian parameters of the binary, four additional post-Keplerian parameters, including the inclination angle of the binary's orbit, $i$. We briefly discuss feasibility of practical implementation of these theoretical results, which crucially depends on further progress in the technique of precision Doppler measurements.

  19. Gravitational Waves from Coalescing Binary Black Holes: Theoretical and Experimental Challenges

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    A network of ground-based interferometric gravitational wave detectors (LIGO/VIRGO/GEO/...) is currently taking data near its planned sensitivity. Coalescing black hole binaries are among the most promising, and most exciting, gravitational wave sources for these detectors. The talk will review the theoretical and experimental challenges that must be met in order to successfully detect gravitational waves from coalescing black hole binaries, and to be able to reliably measure the physical parameters of the source (masses, spins, ...).

  20. Non-linear multipole interactions and gravitational-wave octupole modes for inspiralling compact binaries to third-and-a-half post-Newtonian order

    E-Print Network [OSTI]

    Guillaume Faye; Luc Blanchet; Bala R. Iyer

    2015-02-04T23:59:59.000Z

    This paper is motivated by the need to improve the post-Newtonian (PN) amplitude accuracy of waveforms for gravitational waves generated by inspiralling compact binaries, both for use in data analysis and in the comparison between post-Newtonian approximations and numerical relativity computations. It presents: (i) the non-linear couplings between multipole moments of general post-Newtonian matter sources up to order 3.5PN, including all contributions from tails, tails-of-tails and the non-linear memory effect; and (ii) the source mass-type octupole moment of (non-spinning) compact binaries up to order 3PN, which permits to complete the expressions of the octupole modes (3,3) and (3,1) of the gravitational waveform to order 3.5PN. At this occasion we reconfirm by means of independent calculations our earlier results concerning the source mass-type quadrupole moment to order 3PN. Related discussions on factorized resummed waveforms and the occurence of logarithmic contributions to high order are also included.

  1. Testing eccentricity pumping mechanisms to model eccentric long period sdB binaries with MESA

    E-Print Network [OSTI]

    Vos, Joris; Marchant, Pablo; Van Winckel, Hans

    2015-01-01T23:59:59.000Z

    Hot subdwarf-B stars in long-period binaries are found to be on eccentric orbits, even though current binary-evolution theory predicts those objects to be circularised before the onset of Roche-lobe overflow (RLOF). We aim to find binary-evolution mechanisms that can explain these eccentric long-period orbits, and reproduce the currently observed period-eccentricity diagram. Three different processes are considered; tidally-enhanced wind mass-loss, phase-dependent RLOF on eccentric orbits and the interaction between a circumbinary disk and the binary. The binary module of the stellar-evolution code MESA (Modules for Experiments in Stellar Astrophysics) is extended to include the eccentricity-pumping processes. The effects of different input parameters on the final period and eccentricity of a binary-evolution model are tested with MESA. The end products of models with only tidally-enhanced wind mass-loss can indeed be eccentric, but these models need to lose too much mass, and invariably end up with a helium ...

  2. The detectability of eccentric compact binary coalescences with advanced gravitational-wave detectors

    E-Print Network [OSTI]

    Michael Coughlin; Patrick Meyers; Eric Thrane; Jialun Luo; Nelson Christensen

    2014-12-19T23:59:59.000Z

    Compact binary coalescences are a promising source of gravitational waves for second-generation interferometric gravitational-wave detectors such as advanced LIGO and advanced Virgo. While most binaries are expected to possess circular orbits, some may be eccentric, for example, if they are formed through dynamical capture. Eccentric orbits can create difficulty for matched filtering searches due to the challenges of creating effective template banks to detect these signals. In previous work, we showed how seedless clustering can be used to detect low-mass ($M_\\text{total}\\leq10M_\\odot$) compact binary coalescences for both spinning and eccentric systems, assuming a circular post-Newtonian expansion. Here, we describe a parameterization that is designed to maximize sensitivity to low-eccentricity ($0\\leq\\epsilon\\leq0.6$) systems, derived from the analytic equations. We show that this parameterization provides a robust and computationally efficient method for detecting eccentric low-mass compact binaries. Based on these results, we conclude that advanced detectors will have a chance of detecting eccentric binaries if optimistic models prove true. However, a null observation is unlikely to firmly rule out models of eccentric binary populations.

  3. Caustic Crossing Microlensing Event by Binary MACHOs and Time Scale Bias

    E-Print Network [OSTI]

    Mareki Honma

    1998-11-25T23:59:59.000Z

    Caustic crossing microlensing events provide us a unique opportunity to measure the relative proper motion of the lens to the source, and so those caused by binary MACHOs are of great importance for understanding the structure of the Galactic halo and the nature of MACHOs. The microlensing event 98-SMC-01, occurred in June 1998, is the first event for which the proper motion is ever measured through the caustic crossing, and this event may be caused by binary MACHOs as we argue in this Letter. Motivated by the possible existence of binary MACHOs, we have performed the Monte Carlo simulations of caustic crossing events by binary MACHOs and investigated the properties and detectability of the events. Our calculation shows that typical caustic crossing events have the interval between two caustic crossings ($t_{\\rm cc}$) of about 5 days. We argue that with the current strategy of binary event search the proper motions of these typical events are not measurable because of the short time scale. Therefore the proper motion distribution measured from caustic crossing events suffers significantly from {`}time scale bias{'}, which is a bias toward finding long time scale events and hence slowly moving lenses. We predict there are two times more short time scale events ($t_{\\rm cc}\\le 10$ days) than long time scale events ($t_{\\rm cc}\\ge 10$ days), and propose an hourly monitoring observation instead of the nightly monitoring currently undertaken to detect caustic crossing events by binary MACHOs more efficiently.

  4. Evolution of Compact-Binary Populations in Globular Clusters: A Boltzmann Study. I. The Continuous Limit

    E-Print Network [OSTI]

    Sambaran Banerjee; Pranab Ghosh

    2007-08-10T23:59:59.000Z

    We explore a Boltzmann scheme for studying the evolution of compact binary populations of globular clusters. We include processes of compact-binary formation by tidal capture and exchange encounters, binary destruction by dissociation and other mechanisms, and binary hardening by encounters, gravitational radiation and magnetic braking, as also the orbital evolution during mass transfer, following Roche lobe contact. For the encounter processes which are stochastic in nature, we study the probabilistic, continuous limit in this introductory work, deferring the specific handling of the stochastic terms to the next step. We focus on the evolution of (a) the number of X-ray sources N_{XB} in globular clusters, and (b) the orbital-period distribution of the X-ray binaries, as a result of the above processes. We investigate the dependence of N_{XB} on two essential cluster properties, namely, the star-star and star-binary encounter-rate parameters 'Gamma' and 'gamma', which we call Verbunt parameters. We compare our model results with observation, showing that the model values of N_{XB} and their expected scaling with the Verbunt parameters are in good agreement with results from recent X-ray observations of Galactic globular clusters, encouraging us to build more detailed models.

  5. A triple origin for the lack of tight coplanar circumbinary planets around short-period binaries

    E-Print Network [OSTI]

    Hamers, Adrian S; Zwart, Simon F Portegies

    2015-01-01T23:59:59.000Z

    Detection of transiting circumbinary planets is more tractable around short-period binaries, however, no such binaries were found with orbits shorter than 7 days. Short-period main sequence binaries have been suggested to form in triple systems, through a combination of secular Kozai-Lidov cycles and tidal friction (KLCTF). Here, we show that coplanar circumbinary transiting planets are unlikely to exist around short-period binaries, due to triple evolution. We use secular analysis, $N$-body simulations and analytic considerations as well as population synthesis models to characterize their overall properties. We find that the existence of a circumbinary planet in a triple is likely to produce one of the following outcomes. (1) Sufficiently massive planets in tight and/or coplanar orbits around the inner binary can partially or completely quench the KL evolution, `shielding' the inner binary from the secular effects of the tertiary, and not allowing the KLCTF process to take place. In this case, the inner bin...

  6. Magnetically-induced outflows from binary neutron star merger remnants

    E-Print Network [OSTI]

    Siegel, Daniel M

    2015-01-01T23:59:59.000Z

    Recent observations by the Swift satellite have revealed long-lasting ($\\sim 10^2-10^5\\,\\mathrm{s}$), "plateau-like" X-ray afterglows in the vast majority of short gamma-ray bursts events. This has put forward the idea of a long-lived millisecond magnetar central engine being generated in a binary neutron star (BNS) merger and being responsible for the sustained energy injection over these timescales ("magnetar model"). We elaborate here on recent simulations that investigate the early evolution of such a merger remnant in general-relativistic magnetohydrodynamics. These simulations reveal very different conditions than those usually assumed for dipole spin-down emission in the magnetar model. In particular, the surrounding of the newly formed NS is polluted by baryons due to a dense, highly magnetized and isotropic wind from the stellar surface that is induced by magnetic field amplification in the interior of the star. The timescales and luminosities of this wind are compatible with early X-ray afterglows, ...

  7. Planet formation in post-common-envelope binaries

    E-Print Network [OSTI]

    Schleicher, Dominik; V鰈schow, Marcel; Banerjee, Robi; Hessman, Frederic V

    2015-01-01T23:59:59.000Z

    To understand the evolution of planetary systems, it is important to investigate planets in highly evolved stellar systems, and to explore the implications of their observed properties with respect to potential formation scenarios. Observations suggest the presence of giant planets in post-common-envelope binaries (PCEBs). A particularly well-studied system with planetary masses of 1.7 M_J and 7.0 M_J is NN Ser. We show here that a pure first-generation scenario where the planets form before the common envelope (CE) phase and the orbits evolve due to the changes in the gravitational potential is inconsistent with the current data. We propose a second-generation scenario where the planets are formed from the material that is ejected during the CE, which may naturally explain the observed planetary masses. In addition, hybrid scenarios where the planets form before the CE and evolve due to the accretion of the ejected gas appear as a realistic possibility.

  8. Summary of Historical Production for Nevada Binary Facilities

    SciTech Connect (OSTI)

    Mines, Greg; Hanson, Hillary

    2001-09-01T23:59:59.000Z

    The analysis described was initiated to validate inputs used in the US Department of Energy抯 (DOE) economic modeling tool GETEM (Geothermal Electricity Technology Evaluation Model) by using publically available data to identify production trends at operating geothermal binary facilities in the state of Nevada. Data required for this analysis was obtained from the Nevada Bureau of Mines and Geology (NBMG), whom received the original operator reports from the Nevada Division of Minerals (NDOM). The data from the NBMG was inputted into Excel files that have been uploaded to the DOE抯 National Geothermal Data System (NGDS). Once data was available in an Excel format, production trends for individual wells and facilities could be established for the periods data was available (thru 2009). Additionally, this analysis identified relationships existing between production (temperature and flow rates), power production and plant conversion efficiencies. The data trends showed that temperature declines have a significant impact on power production, and that in some instances operators increased production flow rate to offset power declines. The production trends with time that were identified are being used to update GETEM抯 default inputs.

  9. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    SciTech Connect (OSTI)

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01T23:59:59.000Z

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  10. Summary of Historical Production for Nevada Binary Facilities

    SciTech Connect (OSTI)

    Mines, Greg; Hanson, Hillary

    2014-09-01T23:59:59.000Z

    The analysis described was initiated to validate inputs used in the US Department of Energy抯 (DOE) economic modeling tool GETEM (Geothermal Electricity Technology Evaluation Model) by using publically available data to identify production trends at operating geothermal binary facilities in the state of Nevada. Data required for this analysis was obtained from the Nevada Bureau of Mines and Geology (NBMG), whom received the original operator reports from the Nevada Division of Minerals (NDOM). The data from the NBMG was inputted into Excel files that have been uploaded to the DOE抯 National Geothermal Data System (NGDS). Once data was available in an Excel format, production trends for individual wells and facilities could be established for the periods data was available (thru 2009). Additionally, this analysis identified relationships existing between production (temperature and flow rates), power production and plant conversion efficiencies. The data trends showed that temperature declines have a significant impact on power production, and that in some instances operators increased production flow rate to offset power declines. The production trends with time that were identified are being used to update GETEM抯 default inputs.

  11. Magnetic energy production by turbulence in binary neutron star mergers

    E-Print Network [OSTI]

    Zrake, Jonathan

    2013-01-01T23:59:59.000Z

    The simultaneous detection of electromagnetic and gravitational wave emission from merging neutron star binaries would aid greatly in their discovery and interpretation. By studying turbulent amplification of magnetic fields in local high-resolution simulations of neutron star merger conditions, we demonstrate that magnetar-level (~10^16) G fields are present throughout the merger duration. We find that the small-scale turbulent dynamo converts 60% of the randomized kinetic energy into magnetic fields on a merger time scale. Since turbulent magnetic energy dissipates through reconnection events which accelerate relativistic electrons, turbulence may facilitate the conversion of orbital kinetic energy into radiation. If 10^-4 of the ~ 10^53 erg of orbital kinetic available gets processed through reconnection, and creates radiation in the 15-150 keV band, then the fluence at 200 Mpc would be 10^-7 erg/cm^2, potentially rendering most merging neutron stars in the advanced LIGO and Virgo detection volumes detecta...

  12. Preliminary study of pseudorandom binary sequence pulsing of ORELA

    SciTech Connect (OSTI)

    Larson, N. M.; Olsen, D. K.

    1980-03-01T23:59:59.000Z

    It has been suggested that pseudorandom binary sequence (PRBS) pulsing might enhance the performance of the Oak Ridge Electron Linear Accelerator (ORELA) for neutron-induced, time-of-flight (TOF) cross-section measurements. In this technical memorandum, equations are developed for expected count rates, statistical variances, and backgrounds for a pulsing scheme in which a PRBS is superimposed on the periodic equalintensity ORELA bursts. Introduction of the PRBS modification permits neutrons of different energies originating from different bursts to reach the detector simultaneously, and the signal corresponding to a unique flight time to be extracted mathematically. Relative advantages and disadvantages of measurements from conventional and PRBS pulsing modes are discussed in terms of counting statistics and backgrounds. Computer models of TOF spectra are generated for both pulsing modes, using as examples a 20-meter /sup 233/U fission-chamber measurement and a 155-meter /sup 238/U sample-in transmission measurement. Detailed comparisons of PRBS vs conventional results are presented. This study indicates that although PRBS pulsing could enhance ORELA performance for selected measurements, for general ORELA operation the disadvantages from PRBS pulsing probably outweigh the advantages.

  13. Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers

    E-Print Network [OSTI]

    Just, Oliver; Pulpillo, Ricard Ardevol; Goriely, Stephane; Janka, H -Thomas

    2015-01-01T23:59:59.000Z

    We present a comprehensive study of r-process element nucleosynthesis in the ejecta of compact binary mergers (CBMs) and their relic black-hole (BH)-torus systems. The evolution of the BH-accretion tori is simulated for seconds with a Newtonian hydrodynamics code including viscosity effects, pseudo-Newtonian gravity for rotating BHs, and an energy-dependent two-moment closure scheme for the transport of electron neutrinos and antineutrinos. The investigated cases are guided by relativistic double neutron star (NS-NS) and NS-BH merger models, producing ~3-6 Msun BHs with rotation parameters of A~0.8 and tori of 0.03-0.3 Msun. Our nucleosynthesis analysis includes the dynamical (prompt) ejecta expelled during the CBM phase and the neutrino and viscously driven outflows of the relic BH-torus systems. While typically ~20-25% of the initial accretion-torus mass are lost by viscously driven outflows, neutrino-powered winds contribute at most another ~1%, but neutrino heating enhances the viscous ejecta significantl...

  14. Filtering post-Newtonian gravitational waves from coalescing binaries

    E-Print Network [OSTI]

    B. S. Sathyaprakash

    1994-11-15T23:59:59.000Z

    Gravitational waves from inspiralling binaries are expected to be detected using a data analysis technique known as {\\it matched filtering.} This technique is applicable whenever the form of the signal is known accurately. Though we know the form of the signal precisely, we will not know {\\it a priori} its parameters. Hence it is essential to filter the raw output through a host of search templates each corresponding to different values of the parameters. The number of search templates needed in detecting the Newtonian waveform characterized by three independent parameters is itself several thousands. With the inclusion of post-Newtonian corrections the inspiral waveform will have four independent parameters and this, it was thought, would lead to an increase in the number of filters by several orders of magnitude---an unfavorable feature since it would drastically slow down data analysis. In this paper I show that by a judicious choice of signal parameters we can work, even when the first post-Newtonian corrections are included, with as many number of parameters as in the Newtonian case. In other words I demonstrate that the effective dimensionality of the signal parameter space does not change when first post-Newtonian corrections are taken into account.

  15. Measuring the configurational temperature of a binary disc packing

    E-Print Network [OSTI]

    Song-Chuan Zhao; Matthias Schr鰐er

    2014-06-20T23:59:59.000Z

    Jammed packings of granular materials differ from systems normally described by statistical mechanics in that they are athermal. In recent years a statistical mechanics of static granular media has emerged where the thermodynamic temperature is replaced by a configurational temperature X which describes how the number of mechanically stable configurations depends on the volume. Four different methods have been suggested to measure X. Three of them are computed from properties of the Voronoi volume distribution, the fourth takes into account the contact number and the global volume fraction. This paper answers two questions using experimental binary disc packings: First we test if the four methods to measure compactivity provide identical results when applied to the same dataset. We find that only two of the methods agree quantitatively. Secondly, we test if X is indeed an intensive variable; this becomes true only for samples larger than roughly 200 particles. This result is shown to be due to recently found correlations between the particle volumes [Zhao et al., Europhys. Lett., 2012, 97, 34004].

  16. Magnetically-induced outflows from binary neutron star merger remnants

    E-Print Network [OSTI]

    Daniel M. Siegel; Riccardo Ciolfi

    2015-05-06T23:59:59.000Z

    Recent observations by the Swift satellite have revealed long-lasting ($\\sim 10^2-10^5\\,\\mathrm{s}$), "plateau-like" X-ray afterglows in the vast majority of short gamma-ray bursts events. This has put forward the idea of a long-lived millisecond magnetar central engine being generated in a binary neutron star (BNS) merger and being responsible for the sustained energy injection over these timescales ("magnetar model"). We elaborate here on recent simulations that investigate the early evolution of such a merger remnant in general-relativistic magnetohydrodynamics. These simulations reveal very different conditions than those usually assumed for dipole spin-down emission in the magnetar model. In particular, the surrounding of the newly formed NS is polluted by baryons due to a dense, highly magnetized and isotropic wind from the stellar surface that is induced by magnetic field amplification in the interior of the star. The timescales and luminosities of this wind are compatible with early X-ray afterglows, such as the "extended emission". These isotropic winds are a generic feature of BNS merger remnants and thus represent an attractive alternative to current models of early X-ray afterglows. Further implications to BNS mergers and short gamma-ray bursts are discussed.

  17. MODELING X-RAY BINARY EVOLUTION IN NORMAL GALAXIES: INSIGHTS FROM SINGS

    SciTech Connect (OSTI)

    Tzanavaris, P.; Jenkins, L.; Lehmer, B. D.; Hornschemeier, A.; Ptak, A.; Basu-Zych, A. R. [Laboratory for X-ray Astrophysics, NASA/Goddard Space Flight Center, Mail Code 662, Greenbelt, MD 20771 (United States); Fragos, T.; Zezas, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02139 (United States); Tremmel, M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Kalogera, V. [Center for Interdisciplinary Research and Exploration in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2013-09-10T23:59:59.000Z

    We present the largest-scale comparison to date between observed extragalactic X-ray binary (XRB) populations and theoretical models of their production. We construct observational X-ray luminosity functions (oXLFs) using Chandra observations of 12 late-type galaxies from the Spitzer Infrared Nearby Galaxy Survey. For each galaxy, we obtain theoretical XLFs (tXLFs) by combining XRB synthetic models, constructed with the population synthesis code StarTrack, with observational star formation histories (SFHs). We identify highest-likelihood models both for individual galaxies and globally, averaged over the full galaxy sample. Individual tXLFs successfully reproduce about half of the oXLFs, but for some galaxies we are unable to find underlying source populations, indicating that galaxy SFHs and metallicities are not well matched and/or that XRB modeling requires calibration on larger observational samples. Given these limitations, we find that the best models are consistent with a product of common envelope ejection efficiency and central donor concentration {approx_equal} 0.1, and a 50% uniform-50% ''twins'' initial mass-ratio distribution. We present and discuss constituent subpopulations of tXLFs according to donor, accretor, and stellar population characteristics. The galaxy-wide X-ray luminosity due to low-mass and high-mass XRBs, estimated via our best global model tXLF, follows the general trend expected from the L{sub X} -star formation rate and L{sub X} -stellar mass relations of Lehmer et al. Our best models are also in agreement with modeling of the evolution of both XRBs over cosmic time and of the galaxy X-ray luminosity with redshift.

  18. PSR J17232837: AN ECLIPSING BINARY RADIO MILLISECOND PULSAR

    SciTech Connect (OSTI)

    Crawford, Fronefield [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Lyne, Andrew G. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Stairs, Ingrid H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kaplan, David L. [Physics Department, University of Wisconsin - Milwaukee, Milwaukee, WI 53211 (United States); McLaughlin, Maura A.; Lorimer, Duncan R. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Freire, Paulo C. C.; Kramer, Michael [Max-Planck-Institut f黵 Radioastronomie, auf dem Huegel 69, D-53121 Bonn (Germany); Burgay, Marta; D'Amico, Nichi; Possenti, Andrea [INAF - Osservatorio Astronomico di Cagliari, Poggio dei Pini, I-09012 Capoterra (Italy); Camilo, Fernando [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Faulkner, Andrew [Cavendish Laboratory, University of Cambridge, J. J. Thompson Avenue, Cambridge, CB3 0HE (United Kingdom); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Steeghs, Danny, E-mail: fcrawfor@fandm.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2013-10-10T23:59:59.000Z

    We present a study of PSR J17232837, an eclipsing, 1.86 ms millisecond binary radio pulsar discovered in the Parkes Multibeam survey. Radio timing indicates that the pulsar has a circular orbit with a 15 hr orbital period, a low-mass companion, and a measurable orbital period derivative. The eclipse fraction of ?15% during the pulsar's orbit is twice the Roche lobe size inferred for the companion. The timing behavior is significantly affected by unmodeled systematics of astrophysical origin, and higher-order orbital period derivatives are needed in the timing solution to account for these variations. We have identified the pulsar's (non-degenerate) companion using archival ultraviolet, optical, and infrared survey data and new optical photometry. Doppler shifts from optical spectroscopy confirm the star's association with the pulsar and indicate a pulsar-to-companion mass ratio of 3.3 0.5, corresponding to a companion mass range of 0.4 to 0.7 M{sub ?} and an orbital inclination angle range of between 30 and 41, assuming a pulsar mass range of 1.4-2.0 M{sub ?}. Spectroscopy indicates a spectral type of G for the companion and an inferred Roche-lobe-filling distance that is consistent with the distance estimated from radio dispersion. The features of PSR J17232837 indicate that it is likely a 'redback' system. Unlike the five other Galactic redbacks discovered to date, PSR J17232837 has not been detected as a ?-ray source with Fermi. This may be due to an intrinsic spin-down luminosity that is much smaller than the measured value if the unmeasured contribution from proper motion is large.

  19. Near-Infrared Light Curves of the Black Hole Binary A0620-00

    E-Print Network [OSTI]

    C. S. Froning; E. L. Robinson

    2001-01-31T23:59:59.000Z

    We measured the near-infrared orbital light curve of the black hole binary A0620-00 in 1995 and 1996. The light curves show an asymmetric, double-humped modulation with extra emission in the peak at orbital phase 0.75. There were no significant changes in the shape of the light curve over the one-year observation period. There were no sharp dips in the light curves nor reversals of the asymmetry between the two peaks as seen in earlier observations. The light curves are well fit by models incorporating ellipsoidal variations from the mass-losing K-type star plus a beamed bright spot on the accretion disk around the compact star. The long-term stability of the light curve shape rules out superhumps and star spots as sources of asymmetry when we observed A0620-00. The ellipsoidal variations yield a lower limit i >= 38 deg on the orbital inclination. The light curves show no eclipse features, which places an upper limit i <= 75 deg. This range of inclinations constrains the mass of the compact object to 3.3 < M_1 < 13.6 Msun. The light curves do not further constrain the orbital inclination because the contribution of the accretion disk to the observed flux is unknown. We argue that a previous attempt to measure the near-infrared flux from the accretion disk using the dilution of the 12CO(2,0) bandhead in the spectrum of the K star is not reliable because the band strength depends strongly on surface gravity.

  20. The Low-Mass X-ray Binary-Globular Cluster connection in NGC 4472

    E-Print Network [OSTI]

    Arunav Kundu; Tom Maccarone; Steve Zepf

    2002-06-13T23:59:59.000Z

    We have analyzed the low mass X-ray binary (LMXB) candidates in a Chandra observation of the giant elliptical galaxy NGC 4472. In a region observed by the Hubble Space Telescope, approximately 40% of the bright (L_X >= 10^37 ergs/s) LMXBs are associated with optically identified globular clusters (GC). This is significantly higher than the fraction of bright LMXBs in Galactic GCs and confirms that GCs are the dominant sites of LMXB formation in early type galaxies. The approximately 4% of NGC 4472 GCs hosting bright LMXBs, on the other hand, is remarkably similar to the fraction of GCs with LMXBs in every other galaxy. Although statistical tests suggest that the luminosity of a cluster is an important driver of LMXB formation in GCs, this appears largely to be a consequence of the greater number of stars in bright clusters. The metallicity of GCs is a strong determinant of LMXB specific frequency, with metal-rich clusters about 3 times more likely to host LMXBs than metal-poor ones. There are weaker dependences on the size of a GC and its distance from the center of the galaxy. The X-ray luminosity does not depend significantly on the properties of the host GC. Furthermore, the spatial distribution and X-ray luminosity function of LMXBs within and outside GCs are indistinguishable. The X-ray luminosity function of both GC-LMXBs and non-GC-LMXBs reveal a break at approximately 3x10^38 ergs/s strongly suggesting that the brightest LMXBs are black hole accretors.

  1. Mass and Angular Momentum Transfer in the Massive Algol Binary RY Persei

    E-Print Network [OSTI]

    P. Barai; D. R. Gies; E. Choi; V. Das; R. Deo; W. Huang; K. Marshall; M. V. McSwain; C. Ogden; A. Osterman; R. L. Riddle; J. L. Seymour Jr; D. W. Wingert; A. B. Kaye; G. J. Peters

    2004-04-02T23:59:59.000Z

    We present an investigation of H-alpha emission line variations observed in the massive Algol binary, RY Per. We give new radial velocity data for the secondary based upon our optical spectra and for the primary based upon high dispersion UV spectra. We present revised orbital elements and an estimate of the primary's projected rotational velocity (which indicates that the primary is rotating 7 times faster than synchronous). We use a Doppler tomography algorithm to reconstruct the individual primary and secondary spectra in the region of H-alpha, and we subtract the latter from each of our observations to obtain profiles of the primary and its disk alone. Our H-alpha observations of RY Per show that the mass gaining primary is surrounded by a persistent but time variable accretion disk. The profile that is observed outside-of-eclipse has weak, double-peaked emission flanking a deep central absorption, and we find that these properties can be reproduced by a disk model that includes the absorption of photospheric light by the band of the disk seen in projection against the face of the star. We developed a new method to reconstruct the disk surface density distribution from the ensemble of H-alpha profiles observed around the orbit, and this method accounts for the effects of disk occultation by the stellar components, the obscuration of the primary by the disk, and flux contributions from optically thick disk elements. The resulting surface density distribution is elongated along the axis joining the stars, in the same way as seen in hydrodynamical simulations of gas flows that strike the mass gainer near trailing edge of the star. This type of gas stream configuration is optimal for the transfer of angular momentum, and we show that rapid rotation is found in other Algols that have passed through a similar stage.

  2. DISCOVERY OF TWO VERY WIDE BINARIES WITH ULTRACOOL COMPANIONS AND A NEW BROWN DWARF AT THE L/T TRANSITION

    SciTech Connect (OSTI)

    Muzic, Koraljka; Radigan, Jacqueline; Jayawardhana, Ray [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Ivanov, Valentin D.; Boffin, Henri M. J.; Jones, David; Tyndall, Amy [European Southern Observatory, Alonso de Cordova 3107, Casilla 19, Santiago 19001 (Chile); Faherty, Jacqueline K. [Department of Astronomy, University of Chile, Camino El Observatorio 1515, Casilla 36-D, Santiago (Chile); Kurtev, Radostin G.; Borissova, Jura [Departamento de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Playa Ancha, Casilla 53, Valparaiso (Chile); Nunez, Alejandro; Cruz, Kelle [Department of Astrophysics, American Museum of Natural History, New York, NY, 10024 (United States); Hainaut, Olivier [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen (Germany); Metchev, Stanimir, E-mail: kmuzic@eso.org [Department of Physics and Astronomy, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794-3800 (United States)

    2012-12-01T23:59:59.000Z

    We present the discovery and spectroscopic follow-up of a nearby late-type L dwarf (2M0614+3950), and two extremely wide very low mass binary systems (2M0525-7425AB and 2M1348-1344AB), resulting from our search for common proper motion pairs containing ultracool components in the Two Micron All Sky Survey and the Wide-field Infrared Survey Explorer catalogs. The near-infrared spectrum of 2M0614+3950 indicates a spectral type L9 {+-} 1 object residing at a distance of 26.0 {+-} 1.8 pc. The optical spectrum of 2M0525-7425A reveals an M3.0 {+-} 0.5 dwarf primary, accompanied by a secondary previously classified as L2. The system has an angular separation of {approx}44'', equivalent to {approx}2000 AU at a distance of 46.0 {+-} 3.0 pc. Using optical and infrared spectra, respectively, we classify the components of 2M1348-1344AB as M4.5 {+-} 0.5 and T5.5 {+-} 1. The angular separation of {approx}68'' is equivalent to {approx}1400 AU at a distance of 20.7 {+-} 1.4 pc. 2M1348-1344AB is one of only six very wide (separation >1000 AU) systems containing late T dwarfs known to date.

  3. Investigation of the electrocatalysis for oxygen reduction reaction by Pt and binary Pt alloys: an XRD, XAS and electrochemical study

    SciTech Connect (OSTI)

    Mukerjee, S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Srinivasan, S. [Texas A and M Univ., College Station, TX (United States). Texas Engineering Experiment Station

    1995-12-31T23:59:59.000Z

    Electrocatalysis for the oxygen reduction reaction (ORR) on five binary Pt alloy electrocatalysts (PtCr/C, PtMn/C, PtFe/C, PtCo/C and PtNi/C) supported on carbon have been investigated. The electrochemical characteristics for ORR in a proton conducting fuel cell environment has been correlated with the electronic and structural parameters determined under in situ conditions using XANES and EXAFS technique respectively. Results indicate that all the alloys possess higher Pt 5d band vacancies as compared to Pt/C. There is also evidence of lattice contraction in the alloys (supported by XRD results). Further, the Pt/C shows increase in Pt 5 d band vacancies during potential transitions from 0.54 to 0.84 V vs. RHE, which has been ration@ on the basis of OH type adsorption. In contrast to this, the alloys do not exhibit such an enhancement. Detailed EXAFS analysis supports the presence of OH species on Pt/C and its relative absence in the alloys. Correlation of the electrochemical results with bond distances and d-band vacancies show a volcano type behavior with the PtCr/C on top of the curve.

  4. Type II superconductivity and magnetic flux transport in neutrons stars

    E-Print Network [OSTI]

    P. B. Jones

    2005-10-13T23:59:59.000Z

    The transition to a type II proton superconductor which is believed to occur in a cooling neutron star is accompanied by changes in the equation of hydrostatic equilibrium and by the formation of proton vortices with quantized magnetic flux. Analysis of the electron Boltzmann equation for this system and of the proton supercurrent distribution formed at the transition leads to the derivation of a simple expression for the transport velocity of magnetic flux in the liquid interior of a neutron star. This shows that flux moves easily as a consequence of the interaction between neutron and proton superfluid vortices during intervals of spin-down or spin-up in binary systems. The differences between the present analysis and those of previous workers are reviewed and an error in the paper of Jones (1991) is corrected.

  5. X-RAY BINARY EVOLUTION ACROSS COSMIC TIME

    SciTech Connect (OSTI)

    Fragos, T.; Zezas, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lehmer, B.; Tzanavaris, P. [Department of Physics and Astronomy, The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States)] [Department of Physics and Astronomy, The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Tremmel, M. [Department of Astronomy, University of Washington, Box 351580, U.W., Seattle, WA 98195-1580 (United States)] [Department of Astronomy, University of Washington, Box 351580, U.W., Seattle, WA 98195-1580 (United States); Basu-Zych, A.; Hornschemeier, A.; Jenkins, L.; Ptak, A. [NASA Goddard Space Flight Centre, Code 662, Greenbelt, MD 20771 (United States)] [NASA Goddard Space Flight Centre, Code 662, Greenbelt, MD 20771 (United States); Belczynski, K. [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland)] [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Kalogera, V., E-mail: tfragos@cfa.harvard.edu [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2013-02-10T23:59:59.000Z

    High-redshift galaxies permit the study of the formation and evolution of X-ray binary (XRB) populations on cosmological timescales, probing a wide range of metallicities and star formation rates (SFRs). In this paper, we present results from a large-scale population synthesis study that models the XRB populations from the first galaxies of the universe until today. We use as input to our modeling the Millennium II cosmological simulation and the updated semi-analytic galaxy catalog by Guo et al. to self-consistently account for the star formation history and metallicity evolution of the universe. Our modeling, which is constrained by the observed X-ray properties of local galaxies, gives predictions about the global scaling of emission from XRB populations with properties such as SFR and stellar mass, and the evolution of these relations with redshift. Our simulations show that the X-ray luminosity density (X-ray luminosity per unit volume) from XRBs in our universe today is dominated by low-mass XRBs, and it is only at z {approx}> 2.5 that high-mass XRBs become dominant. We also find that there is a delay of {approx}1.1 Gyr between the peak of X-ray emissivity from low-mass XRBs (at z {approx} 2.1) and the peak of SFR density (at z {approx} 3.1). The peak of the X-ray luminosity from high-mass XRBs (at z {approx} 3.9) happens {approx}0.8 Gyr before the peak of the SFR density, which is due to the metallicity evolution of the universe.

  6. Binary electrokinetic separation of target DNA from background DNA primers.

    SciTech Connect (OSTI)

    James, Conrad D.; Derzon, Mark Steven

    2005-10-01T23:59:59.000Z

    This report contains the summary of LDRD project 91312, titled ''Binary Electrokinetic Separation of Target DNA from Background DNA Primers''. This work is the first product of a collaboration with Columbia University and the Northeast BioDefense Center of Excellence. In conjunction with Ian Lipkin's lab, we are developing a technique to reduce false positive events, due to the detection of unhybridized reporter molecules, in a sensitive and multiplexed detection scheme for nucleic acids developed by the Lipkin lab. This is the most significant problem in the operation of their capability. As they are developing the tools for rapidly detecting the entire panel of hemorrhagic fevers this technology will immediately serve an important national need. The goal of this work was to attempt to separate nucleic acid from a preprocessed sample. We demonstrated the preconcentration of kilobase-pair length double-stranded DNA targets, and observed little preconcentration of 60 base-pair length single-stranded DNA probes. These objectives were accomplished in microdevice formats that are compatible with larger detection systems for sample pre-processing. Combined with Columbia's expertise, this technology would enable a unique, fast, and potentially compact method for detecting/identifying genetically-modified organisms and multiplexed rapid nucleic acid identification. Another competing approach is the DARPA funded IRIS Pharmaceutical TIGER platform which requires many hours for operation, and an 800k$ piece of equipment that fills a room. The Columbia/SNL system could provide a result in 30 minutes, at the cost of a few thousand dollars for the platform, and would be the size of a shoebox or smaller.

  7. Do X-ray Binary Spectral State Transition Luminosities Vary?

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2003-08-02T23:59:59.000Z

    We tabulate the luminosities of the soft-to-hard state transitions of all X-ray binaries for which there exist good X-ray flux measurements at the time of the transition, good distance estimates, and good mass estimates for the compact star. We show that the state transition luminosities are at about 1-4% of the Eddington rate, markedly smaller than those typically quoted in the literature, with a mean value of 2%. Only the black hole candidate GRO J~1655-40 and the neutron star systems Aql X-1 and 4U 1728-34 have measured state transition luminosities inconsistent with this value at the 1$\\sigma$ level. GRO J~1655-40, in particular, shows a state transition luminosity below the mean value for the other sources at the $4\\sigma$ level. This result, combined with the known inner disk inclination angle (the disk is nearly parallel to the line of sight) from GRO J~1655-40's relativistic jets suggest that the hard X-ray emitting region in GRO J~1655-40 can have a velocity of no more than about $\\beta=0.68$, with a most likely value of about $\\beta=0.52$, and a minimum speed of $\\beta=0.45$, assuming that the variations in state transition luminosities are solely due to relativistic beaming effects. The variance in the state transition luminosities suggests an emission region with a velocity of $\\sim0.2c$. The results are discussed in terms of different emission models for the low/hard state. We also discuss the implications for measuring the dimensionless viscosity parameter $\\alpha$. We also find that if its state transitions occur at typical luminosities, then GX 339-4 is likely to be at a distance of at least 7.6 kpc, much further than typically quoted estimates.

  8. Dust around Type Ia supernovae

    E-Print Network [OSTI]

    Wang, Lifan

    2005-01-01T23:59:59.000Z

    Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows

  9. WIYN open cluster study. LX. Spectroscopic binary orbits in NGC 6819

    SciTech Connect (OSTI)

    Milliman, Katelyn E.; Mathieu, Robert D.; Gosnell, Natalie M. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street Madison, WI 53706 (United States); Geller, Aaron M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Meibom, S鴕en [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Platais, Imants, E-mail: milliman@astro.wisc.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2014-08-01T23:59:59.000Z

    We present the current state of the WOCS radial-velocity (RV) survey for the rich open cluster NGC 6819 (2.5 Gyr) including 93 spectroscopic binary orbits with periods ranging from 1.5 to 8000 days. These results are the product of our ongoing RV survey of NGC 6819 using the Hydra Multi-Object Spectrograph on the WIYN 3.5 m telescope. We also include a detailed analysis of multiple prior sets of optical photometry for NGC 6819. Within a 1 field of view, our stellar sample includes the giant branch, the red clump, and blue straggler candidates, and extends to almost 2 mag below the main sequence (MS) turnoff. For each star observed in our survey we present all RV measurements, the average RV, and velocity variability information. Additionally, we discuss notable binaries from our sample, including eclipsing binaries (WOCS 23009, WOCS 24009, and WOCS 40007), stars noted in Kepler asteroseismology studies (WOCS 4008, WOCS 7009, and WOCS 8007), and potential descendants of past blue stragglers (WOCS 1006 and WOCS 6002). We find the incompleteness-corrected binary fraction for all MS binaries with periods less than 10{sup 4} days to be 22% 3% and a tidal circularization period of 6.2{sub ?1.1}{sup +1.1} days for NGC 6819.

  10. Recoils from unequal-mass, precessing black-hole binaries: The Intermediate Mass Ratio Regime

    E-Print Network [OSTI]

    Zlochower, Yosef

    2015-01-01T23:59:59.000Z

    We revisit the modeling of the properties of the black-hole remnant resulting the merger of a black-hole binary as a function of the parameters of the binary. We provide a set of empirical formulas for the final mass, spin and recoil velocity of the final black hole as a function of the mass ratio and individual spins of the progenitor. In order to determine the fitting coefficients for these formulas, we perform a set of 126 new numerical evolutions of precessing, unequal-mass black-hole binaries, and fit to the resulting remnant mass, spin, and recoil. In order to reduce the complexity of the analysis, we chose configurations that have one of the black holes spinning, with dimensionless spin alpha=0.8, at different angles with respect to the orbital angular momentum, and the other non-spinning. In addition to evolving families of binaries with different spin-inclination angles, we also evolved binaries with mass ratios as small as q=1/6. We use the resulting empirical formulas to predict the probabilities o...

  11. EXPECTED LARGE SYNOPTIC SURVEY TELESCOPE (LSST) YIELD OF ECLIPSING BINARY STARS

    SciTech Connect (OSTI)

    Prsa, Andrej [Department of Astronomy and Astrophysics, Villanova University, 800 East Lancaster Avenue, Villanova, PA 19085 (United States); Pepper, Joshua; Stassun, Keivan G., E-mail: andrej.prsa@villanova.edu [Physics and Astronomy Department, Vanderbilt University, 2201 West End Avenue, Nashville, TN 37235 (United States)

    2011-08-15T23:59:59.000Z

    In this paper, we estimate the Large Synoptic Survey Telescope (LSST) yield of eclipsing binary stars, which will survey {approx}20,000 deg{sup 2} of the southern sky during a period of 10 years in six photometric passbands to r {approx} 24.5. We generate a set of 10,000 eclipsing binary light curves sampled to the LSST time cadence across the whole sky, with added noise as a function of apparent magnitude. This set is passed to the analysis-of-variance period finder to assess the recoverability rate for the periods, and the successfully phased light curves are passed to the artificial-intelligence-based pipeline ebai to assess the recoverability rate in terms of the eclipsing binaries' physical and geometric parameters. We find that, out of {approx}24 million eclipsing binaries observed by LSST with a signal-to-noise ratio >10 in mission lifetime, {approx}28% or 6.7 million can be fully characterized by the pipeline. Of those, {approx}25% or 1.7 million will be double-lined binaries, a true treasure trove for stellar astrophysics.

  12. An alternative parameterisation for binary-lens caustic-crossing events

    E-Print Network [OSTI]

    A. Cassan

    2008-10-15T23:59:59.000Z

    Microlensing events are being discovered and alerted by the two survey teams OGLE and MOA at an increasing rate. Around ten percent of these events involve binary lenses. Such events potentially contain much information on the physical properties of the observed binary systems, which can then be used for e.g. statistical studies on binary objects in the Galactic disk or bulge. However, such events are usually not straightforward to study, because the model equations are strongly non-linear and there are many local minima that can fool the search for the best solution if the parameter space is not inspected with great care. In this work an alternative parameterisation for the binary lens fitting problem is proposed, in which the parameters involved are defined to represent as closely as possible the caustic-crossing features observed in most binary lens light curves. Furthermore, we work out an extension of the method in order to make use of the straight line fold caustic approximation, when the latter applies for both the caustic entry and exit. We introduce an alternative parameterisation in order to confine the exploration of the parameter space to regions where the models only involve caustic crossing at the dates seen in the light curve. We find that the proposed parameterisation provides more robustness to the light curve fitting process, in particular in avoiding a code to get stuck in false minima.

  13. Spin alignment and differential accretion in merging black-hole binaries

    E-Print Network [OSTI]

    Gerosa, Davide; Lodato, Giuseppe; Rosotti, Giovanni

    2015-01-01T23:59:59.000Z

    Interactions between a supermassive black-hole binary and the surrounding accretion disc can both assist the binary inspiral and align the black-hole spins to the disc angular momentum. While binary migration is due to angular-momentum transfer within the circumbinary disc, the spin-alignment process is driven by the mass accreting onto each black hole. Mass transfer between different disc components thus couples the inspiral and the alignment process together. Mass is expected to leak through the cavity cleared by the binary, and preferentially accretes onto the lighter (secondary) black-hole which orbits closer to the disc edge. Low accretion rate onto the heavier (primary) black hole slows the alignment process down. We revisit the problem and develop a semi-analytical model to describe the coupling between gas-driven inspiral and spin alignment, finding that binaries with mass ratio q<~0.2 approach the gravitational-wave driven inspiral in differential misalignment: light secondaries prevent primaries ...

  14. Wolter type i LAMAR

    SciTech Connect (OSTI)

    Catura, R.C.; Joki, E.G.

    1981-11-01T23:59:59.000Z

    Observational objectives for the LAMAR and their influence on the instrument design are discussed. It is concluded that the most important design parameter is the angular resolution of the LAMAR modules since it so strongly influences sensitivity, optical identifications, source confusion, spectral resolution for objective gratings and the ability to resolve small extended sources. A high resolution Wolter Type I LAMAR module is described, its hardware status discussed, and the performance of a LAMAR observatory presented. A promising technique for enhancing the reflectivity of Wolter Type I X-ray optics in a selected bandpass at high energy has been investigated and the performance of the LAMAR module, utilizing this method, has been calculated.

  15. Rappels: 4) Piles Types abstraits de donnes (Abstract Data Type)

    E-Print Network [OSTI]

    Hamel, Sylvie

    Rappels: 4) Piles #12;Types abstraits de donn閑s (Abstract Data Type) IFT2015, A2009, Sylvie Hamel Universit de Montr閍l 1Piles Type de donn閑s Un ensemble de valeurs Un ensemble d'op閞ations Structure de Universit de Montr閍l 2Piles #12;Type abstrait de donn閑s PILE (4.2) Garde en m閙oire des objets

  16. Stellar age versus mass of early-type galaxies in the Virgo Cluster

    E-Print Network [OSTI]

    Thorsten Lisker; Zhanwen Han

    2008-03-17T23:59:59.000Z

    The flux excess of elliptical galaxies in the far-ultraviolet can be reproduced by population synthesis models when accounting for the population of old hot helium-burning subdwarf stars. This has been achieved by Han and coworkers through a quantitative model of binary stellar evolution. Here, we compare the resulting evolutionary population synthesis model to the GALEX far-near ultraviolet colors (FUV-NUV) of Virgo cluster early-type galaxies that were published by Boselli and coworkers. FUV-NUV is reddest at about the dividing luminosity of dwarf and giant galaxies, and becomes increasingly blue for both brighter and fainter luminosities. This behavior can be easily explained by the binary model with a continuous sequence of longer duration and later truncation of star formation at lower galaxy masses. Thus, in contrast to previous conclusions, the GALEX data do not require a dichotomy between the stellar population properties of dwarfs and giants. Their apparently opposite behavior in FUV-NUV occurs naturally when the formation of hot subdwarfs through binary evolution is taken into account.

  17. The Gravitational Wave Background From Coalescing Compact Binaries: A New Method

    E-Print Network [OSTI]

    Evangelista, E F D

    2015-01-01T23:59:59.000Z

    Gravitational waves are perturbations in the spacetime that propagate at the speed of light. The study of such phenomenon is interesting because many cosmological processes and astrophysical objects, such as binary systems, are potential sources of gravitational radiation and can have their emissions detected in the near future by the next generation of interferometric detectors. Concerning the astrophysical objects, an interesting case is when there are several sources emitting in such a way that there is a superposition of signals, resulting in a smooth spectrum which spans a wide range of frequencies, the so-called stochastic background. In this paper, we are concerned with the stochastic backgrounds generated by compact binaries (i.e. binary systems formed by neutron stars and black holes) in the coalescing phase. In particular, we obtain such backgrounds by employing a new method developed in our previous studies.

  18. Optimality of binary power-control in a single cell via majorization

    E-Print Network [OSTI]

    Inaltekin, Hazer

    2011-01-01T23:59:59.000Z

    This paper considers the optimum single cell power-control maximizing the aggregate (uplink) communication rate of the cell when there are peak power constraints at mobile users, and a low-complexity data decoder (without successive decoding) at the base station. It is shown, via the theory of majorization, that the optimum power allocation is binary, which means links are either "on" or "off". By exploiting further structure of the optimum binary power allocation, a simple polynomial-time algorithm for finding the optimum transmission power allocation is proposed, together with a reduced complexity near-optimal heuristic algorithm. Sufficient conditions under which channel-state aware time-division-multiple-access (TDMA) maximizes the aggregate communication rate are established. Finally, a numerical study is performed to compare and contrast the performance achieved by the optimum binary power-control policy with other sub-optimum policies and the throughput capacity achievable via successive decoding. It i...

  19. Wide Binary Effects on Asymmetries in Asymptotic Giant Branch Circumstellar Envelopes

    E-Print Network [OSTI]

    Kim, Hyosun

    2012-01-01T23:59:59.000Z

    Observations of increasingly higher spatial resolution reveal the existence of asymmetries in the circumstellar envelopes of a small fraction of asymptotic giant branch (AGB) stars. Although there is no general consensus for their origin, a binary companion star may be responsible. Within this framework, we investigate the gravitational effects associated with a sufficiently wide binary system, where Roche lobe overflow is unimportant, on the outflowing envelopes of AGB stars using three dimensional hydrodynamic simulations. The effects due to individual binary components are separately studied, enabling investigation of the stellar and circumstellar characteristics in detail. The reflex motion of the AGB star alters the wind velocity distribution, thereby, determining the overall shape of the outflowing envelope. On the other hand, the interaction of the companion with the envelope produces a gravitational wake, which exhibits a vertically thinner shape. The two patterns overlap and form clumpy structures. T...

  20. Impact flux of asteroids and water transport to the habitable zone in binary star systems

    E-Print Network [OSTI]

    Bancelin, D; Eggl, S; Dvorak, R

    2015-01-01T23:59:59.000Z

    By now, observations of exoplanets have found more than 50 binary star systems hosting 71 planets. We expect these numbers to increase as more than 70% of the main sequence stars in the solar neighborhood are members of binary or multiple systems. The planetary motion in such systems depends strongly on both the parameters of the stellar system (stellar separation and eccentricity) and the architecture of the planetary system (number of planets and their orbital behaviour). In case a terrestrial planet moves in the so-called habitable zone (HZ) of its host star, the habitability of this planet depends on many parameters. A crucial factor is certainly the amount of water. We investigate in this work the transport of water from beyond the snow-line to the HZ in a binary star system and compare it to a single star system.

  1. Effect of Ambient Design Temperature on Air-Cooled Binary Plant Output

    SciTech Connect (OSTI)

    Dan Wendt; Greg Mines

    2011-10-01T23:59:59.000Z

    Air-cooled binary plants are designed to provide a specified level of power production at a particular air temperature. Nominally this air temperature is the annual mean or average air temperature for the plant location. This study investigates the effect that changing the design air temperature has on power generation for an air-cooled binary plant producing power from a resource with a declining production fluid temperature and fluctuating ambient temperatures. This analysis was performed for plants operating both with and without a geothermal fluid outlet temperature limit. Aspen Plus process simulation software was used to develop optimal air-cooled binary plant designs for specific ambient temperatures as well as to rate the performance of the plant designs at off-design operating conditions. Results include calculation of annual and plant lifetime power generation as well as evaluation of plant operating characteristics, such as improved power generation capabilities during summer months when electric power prices are at peak levels.

  2. The Runaway Binary LP 400-22 is Leaving the Galaxy

    E-Print Network [OSTI]

    Kilic, Mukremin; Brown, Warren R; Harris, Hugh C; Dahn, Conard C; Agueros, M A; Heinke, Craig O; Kenyon, S J; Panei, J A; Camilo, Fernando

    2013-01-01T23:59:59.000Z

    We present optical spectroscopy, astrometry, radio, and X-ray observations of the runaway binary LP 400-22. We refine the orbital parameters of the system based on our new radial velocity observations. Our parallax data indicate that LP 400-22 is significantly more distant (3 sigma lower limit of 840 pc) than initially predicted. LP 400-22 has a tangential velocity in excess of 830 km/s; it is unbound to the Galaxy. Our radio and X-ray observations fail to detect a recycled millisecond pulsar companion, indicating that LP 400-22 is a double white dwarf system. This essentially rules out a supernova runaway ejection mechanism. Based on its orbit, a Galactic center origin is also unlikely. However, its orbit intersects the locations of several globular clusters; dynamical interactions between LP 400-22 and other binary stars or a central black hole in a dense cluster could explain the origin of this unusual binary.

  3. Warping and tearing of misaligned circumbinary disks around eccentric SMBH binaries

    E-Print Network [OSTI]

    Hayasaki, Kimitake; Okazaki, Atsuo T; Jung, Taehyun; Zhao, Guangyao; Naito, Tsuguya

    2015-01-01T23:59:59.000Z

    We study the warping and tearing of a geometrically thin, non-self-gravitating disk surrounding binary supermassive black holes on an eccentric orbit. The circumbinary disk is significantly misaligned with the binary orbital plane, and is subject to the time-dependent tidal torques. In principle, such a disk is warped and precesses, and is torn into mutually misaligned rings in the region, where the tidal precession torques are stronger than the local viscous torques. We derive the tidal-warp and tearing radii of the misaligned circumbinary disks around eccentric SMBH binaries. We find that in disks with the viscosity parameter, alpha, larger than a critical value depending on the disk aspect ratio, the disk warping appears outside the tearing radius. This condition is expressed as alpha > sqrt{H/3r} for H/r ~material is likely to rapi...

  4. Secular variability, geodetic precession and moment of inertia of binary pulsars

    E-Print Network [OSTI]

    B. P. Gong

    2003-06-04T23:59:59.000Z

    More and more binary pulsars show significant secular variations, in which the measured projected semi-major axis, $\\dot{x}^{obs}$, and the first derivative of orbital period, $\\dot{P}_{b}^{obs}$, are several order of magnitude larger than the prediction of general relativity (GR). This paper shows that the geodetic precession induced orbital effects can explain both $\\dot{x}$ and $\\dot{P}_{b}$ measured in binary pulsars. Moreover, by this model we can automatically estimate the magnitude of the spin angular momenta of the pulsar and its companion star, and therefore the moment of inertia ($10^{44}$g cm$^2$ to $10^{45}$g cm$^2$) of pulsar of binary pulsar systems, which agrees well with theoretical predictions. In other words, the contamination (residual represented by $\\dot{x}$ and $\\dot{P}_{b}$) in pulsar timing measurements might be caused by geodetic precession, an interesting gravitational effect we have been seeking for.

  5. Quadratic-in-spin effects in the orbital dynamics and gravitational-wave energy flux of compact binaries at the 3PN order

    E-Print Network [OSTI]

    Alejandro Boh; Guillaume Faye; Sylvain Marsat; Edward K Porter

    2015-01-07T23:59:59.000Z

    We investigate the dynamics of spinning binaries of compact objects at the next-to-leading order in the quadratic-in-spin effects, which corresponds to the third post-Newtonian order (3PN). Using a Dixon-type multipolar formalism for spinning point particles endowed with spin-induced quadrupoles and computing iteratively in harmonic coordinates the relevant pieces of the PN metric within the near zone, we derive the post-Newtonian equations of motion as well as the equations of spin precession. We find full equivalence with available results. We then focus on the far-zone field produced by those systems and obtain the previously unknown 3PN spin contributions to the gravitational-wave energy flux by means of the multipolar post-Minkowskian (MPM) wave generation formalism. Our results are presented in the center-of-mass frame for generic orbits, before being further specialized to the case of spin-aligned, circular orbits. We derive the orbital phase of the binary based on the energy balance equation and briefly discuss the relevance of the new terms.

  6. A New Method of Accelerated Bayesian Inference for Comparable Mass Binaries in both Ground and Space-Based Gravitational Wave Astronomy

    E-Print Network [OSTI]

    Edward K. Porter

    2014-11-03T23:59:59.000Z

    With the advance in computational resources, Bayesian inference is increasingly becoming the standard tool of practise in GW astronomy. However, algorithms such as Markov Chain Monte Carlo (MCMC) require a large number of iterations to guarantee convergence to the target density. Each chain demands a large number of evaluations of the likelihood function, and in the case of a Hessian MCMC, calculations of the Fisher information matrix for use as a proposal distribution. As each iteration requires the generation of at least one gravitational waveform, we very quickly reach a point of exclusion for current Bayesian algorithms, especially for low mass systems where the length of the waveforms is large and the waveform generation time is on the order of seconds. This suddenly demands a timescale of many weeks for a single MCMC. As each likelihood and Fisher information matrix calculation requires the evaluation of noise-weighted scalar products, we demonstrate that by using the linearity of integration, and the fact that more than 90% of the generation time is spent at frequencies less that one third of the maximum, we can construct composite integrals that speed up the MCMCs for comparable mass binaries by a factor of between 3.5 and 5.5, depending on the waveform length. This method is both source and detector type independent, and can be applied to any waveform that displays significant frequency evolution, such as stellar mass binaries with Advanced LIGO/Virgo, as well as supermassive black holes with eLISA

  7. Accurate Computer Simulation of Phase Equilibrium for Complex Fluid Mixtures. Application to Binaries Involving Isobutene, Methanol, Methyl tert-Butyl Ether, and

    E-Print Network [OSTI]

    Lisal, Martin

    to Binaries Involving Isobutene, Methanol, Methyl tert-Butyl Ether, and n-Butane Martin Li磗al,*,, William R + methyl tert-butyl ether (MTBE) and the binaries formed by methanol with isobutene, MTBE, and n

  8. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect (OSTI)

    Baella, N. O.; Pereira, C. B. [Observat髍io Nacional, Rua Jos Cristino 77, CEP 20921-400, S鉶 Crist髒鉶, Rio de Janeiro (Brazil); Miranda, L. F. [Departamento de F韘ica Aplicada, Facultad de Ciencias, Universidad de Vigo, E-36310 Vigo (Spain)

    2013-11-01T23:59:59.000Z

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J H) versus (H K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J H) versus (H K {sub s}) diagram and the presence of H? line emission in the Stephenson and Sanduleak H? survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the H? emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (?10{sup 8-9} cm{sup 3}), He I emission line intensity ratios, and position in the [O III] ?5007/H? versus [O III] ?4363/H? diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in identifying new S-type yellow symbiotics.

  9. A three-dimensional model for particle dissolution in binary alloys F.J. Vermolen a,*, E. Javierre a

    E-Print Network [OSTI]

    Vuik, Kees

    A three-dimensional model for particle dissolution in binary alloys F.J. Vermolen a,*, E. Javierre, Department of Aerospace Engineering, Kluyverweg 1, 2629 HS Delft, The Netherlands Received 13 September 2006; accepted 20 September 2006 Abstract A three-dimensional model for particle dissolution in binary alloys

  10. A STABILIZED VOLUME-AVERAGING FINITE ELEMENT METHOD FOR FLOW IN POROUS MEDIA AND BINARY ALLOY SOLIDIFICATION SYSTEMS

    E-Print Network [OSTI]

    Zabaras, Nicholas J.

    A STABILIZED VOLUME-AVERAGING FINITE ELEMENT METHOD FOR FLOW IN POROUS MEDIA AND BINARY ALLOY of Mechanical and Aerospace Engineering 188 Frank H. T. Rhodes Hall Cornell University Ithaca, NY 14853 algorithm is presented for the analysis of flow in porous media and in the solidification of binary alloys

  11. The Ising model and critical behavior of transport in binary composite N. B. Murphy and K. M. Golden

    E-Print Network [OSTI]

    Golden, Kenneth M.

    nanotube composites,37 and sea ice.26,27 A key feature of these materials is the critical dependenceThe Ising model and critical behavior of transport in binary composite media N. B. Murphy and K. M) The Ising model and critical behavior of transport in binary composite media N. B. Murphy and K. M. Golden

  12. ISIT 2002, Lausanne, Switzerland, June 30 July 5, 2002 Matched Information Rate Codes for Binary ISI channels1

    E-Print Network [OSTI]

    Kavcic, Aleksandar

    ISI channels1 Xiao Ma, Nedeljko Varnica and Aleksandar Kavci麓c DEAS/Harvard University, Cambridge, MA- proach the channel capacities for binary intersymbol interfer- ence (ISI) channels. The proposed codes-check (LDPC) codes. The whole system is it- eratively decodable. I. SUMMARY Binary ISI channel models

  13. ISIT 2002, Lausanne, Switzerland, June 30 --July 5, 2002 Matched Information Rate Codes for Binary ISI channels 1

    E-Print Network [OSTI]

    Kavcic, Aleksandar

    ISI channels 1 Xiao Ma, Nedeljko Varnica and Aleksandar Kav鸥ci??c DEAS/Harvard University, Cambridge to ap颅 proach the channel capacities for binary intersymbol interfer颅 ence (ISI) channels. The proposed颅density parity颅check (LDPC) codes. The whole system is it颅 eratively decodable. I. SUMMARY Binary ISI channel

  14. Binary and ternary gas mixtures for use in glow discharge closing switches

    DOE Patents [OSTI]

    Hunter, S.R.; Christophorou, L.G.

    1988-04-27T23:59:59.000Z

    Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue if the combines physio-electric properties of the mixture components. 9 figs.

  15. THE HOT R CORONAE BOREALIS STAR DY CENTAURI IS A BINARY

    SciTech Connect (OSTI)

    Kameswara Rao, N. [543, 17th Main, IV Sector, HSR Layout, Bangalore 560102 (India); Lambert, David L.; McArthur, Barbara [W. J. McDonald Observatory, University of Texas, Austin, TX 78712-1083 (United States); Garcia-Hernandez, D. A. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38205 La Laguna (Spain); Simon Jeffery, C. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Woolf, Vincent M., E-mail: nkrao@iiap.res.in, E-mail: dll@astro.as.utexas.edu, E-mail: agarcia@iac.es [Physics Department, University of Nebraska at Omaha, NE 68182-0266 (United States)

    2012-11-20T23:59:59.000Z

    The remarkable hot R Coronae Borealis (RCB) star DY Cen is revealed to be the first and only binary system to be found among the RCB stars and their likely relatives, including the extreme helium stars and the hydrogen-deficient carbon stars. Radial velocity determinations from 1982 to 2010 have shown that DY Cen is a single-lined spectroscopic binary in an eccentric orbit with a period of 39.67 days. It is also one of the hottest and most H-rich member of the class of RCB stars. The system may have evolved from a common envelope to its current form.

  16. Postdoc Appointment Types

    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:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah Project Office Press ReleasesPost-Closure BenefitsAppointment Types

  17. Search for Gravitational Waves from Compact Binary Coalescence in LIGO and Virgo Data from S5 and VSR1

    E-Print Network [OSTI]

    the LIGO Scientific Collaboration; the Virgo Collaboration

    2010-05-25T23:59:59.000Z

    We report the results of the first search for gravitational waves from compact binary coalescence using data from the LIGO and Virgo detectors. Five months of data were collected during the concurrent S5 (LIGO) and VSR1 (Virgo) science runs. The search focused on signals from binary mergers with a total mass between 2 and 35 Msun. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for non-spinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7x10^-3, 2.2x10^-3 and 4.4x10^-4 yr^-1 L_10^-1 respectively, where L_10 is 10^10 times the blue solar luminosity. These upper limits are compared with astrophysical expectations.

  18. A population study of type II bursts in the Rapid Burster

    E-Print Network [OSTI]

    Bagnoli, T; D'Angelo, C R; Galloway, D K

    2015-01-01T23:59:59.000Z

    Type II bursts are thought to arise from instabilities in the accretion flow onto a neutron star in an X-ray binary. Despite having been known for almost 40 years, no model can yet satisfactorily account for all their properties. To shed light on the nature of this phenomenon and provide a reference for future theoretical work, we study the entire sample of Rossi X-ray Timing Explorer data of type II bursts from the Rapid Burster (MXB 1730-335). We find that type II bursts are Eddington-limited in flux, that a larger amount of energy goes in the bursts than in the persistent emission, that type II bursts can be as short as 0.130 s, and that the distribution of recurrence times drops abruptly below 15-18 s. We highlight the complicated feedback between type II bursts and the NS surface thermonuclear explosions known as type I bursts, and between type II bursts and the persistent emission. We review a number of models for type II bursts. While no model can reproduce all the observed burst properties and explain...

  19. What can SimbolX do for gammaray binaries? B. Cerutti, G. Dubus, G. Henri, A. B. Hill and A. Szostek

    E-Print Network [OSTI]

    Recanati, Catherine

    . Particles in gamma璻ay binaries are accelerated with high efficiency to several TeV energiesWhat can Simbol璛 do for gamma璻ay binaries? B. Cerutti, G. Dubus, G. Henri, A. B. Hill and A Grenoble, France Abstract. Gamma璻ay binaries have been uncovered as a new class of Galactic objects

  20. The binary progenitor of Tycho Brahe's 1572 supernova

    E-Print Network [OSTI]

    Ruiz-Lapuente, P; M閚dez, J; Canal, R; Smartt, S J; Filippenko, A V; Kurucz, R L; Chornock, R; Foley, R J; Stanishev, V; Ibata, R; Ruiz-Lapuente, Pilar; Comeron, Fernando; Mendez, Javier; Canal, Ramon; Smartt, Stephen J.; Filippenko, Alexei V.; Kurucz, Robert L.; Chornock, Ryan; Foley, Ryan J.; Stanishev, Vallery; Ibata, Rodrigo

    2004-01-01T23:59:59.000Z

    The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion Unless the companion star is another white dwarf (in which case it should be destroyed by the mass-transfer process itself), it should survive and show distinguishing properties. Tycho's supernova is one of the only two type Ia supernovae observed in our Galaxy, and so provides an opportunity to address observationally the identification of the surviving companion. Here we report a survey of the central region of its remnant, around the position of the explosion, which excludes red giants as the mass donor of the exploding white dwarf. We found a type G0--G2 star, similar to our Sun in surface temperature and luminosity (but lower surface gravity), moving at more than three times the mean veloci...

  1. The binary progenitor of Tycho Brahe's 1572 supernova

    E-Print Network [OSTI]

    Pilar Ruiz-Lapuente; Fernando Comeron; Javier Mendez; Ramon Canal; Stephen J. Smartt; Alexei V. Filippenko; Robert L. Kurucz; Ryan Chornock; Ryan J. Foley; Vallery Stanishev; Rodrigo Ibata

    2004-10-28T23:59:59.000Z

    The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion Unless the companion star is another white dwarf (in which case it should be destroyed by the mass-transfer process itself), it should survive and show distinguishing properties. Tycho's supernova is one of the only two type Ia supernovae observed in our Galaxy, and so provides an opportunity to address observationally the identification of the surviving companion. Here we report a survey of the central region of its remnant, around the position of the explosion, which excludes red giants as the mass donor of the exploding white dwarf. We found a type G0--G2 star, similar to our Sun in surface temperature and luminosity (but lower surface gravity), moving at more than three times the mean velocity of the stars at that distance, which appears to be the surviving companion of the supernova.

  2. A large spectroscopic sample of L and T dwarfs from UKIDSS LAS: peculiar objects, binaries, and space density

    E-Print Network [OSTI]

    Marocco, F; Day-Jones, A C; Pinfield, D J; Lucas, P W; Burningham, B; Zhang, Z H; Smart, R L; Gomes, J I; Smith, L

    2015-01-01T23:59:59.000Z

    We present the spectroscopic analysis of a large sample of late-M, L, and T dwarfs from UKIDSS. Using the YJHK photometry from ULAS and the red-optical photometry from SDSS we selected a sample of 262 brown dwarf candidates and we followed-up 196 of them using X-shooter on the VLT. The large wavelength coverage (0.30-2.48 $\\mu$m) and moderate resolution (R~5000-9000) of X-shooter allowed us to identify peculiar objects including 22 blue L dwarfs, 2 blue T dwarfs, and 2 low gravity M dwarfs. Using a spectral indices-based technique we identified 27 unresolved binary candidates, for which we determined the spectral type of the potential components via spectral deconvolution. The spectra allowed us to measure the equivalent width of the prominent absorption features and to compare them to atmospheric models. Cross-correlating the spectra with a radial velocity standard, we measured the radial velocity for our targets, and we determined the distribution of the sample, which is centred at -1.7$\\pm$1.2 km s$^{-1}$ ...

  3. Binary non-additive hard sphere mixtures: Fluid demixing, asymptotic decay of correlations and free fluid interfaces

    E-Print Network [OSTI]

    Paul Hopkins; Matthias Schmidt

    2010-07-29T23:59:59.000Z

    Using a fundamental measure density functional theory we investigate both bulk and inhomogeneous systems of the binary non-additive hard sphere model. For sufficiently large (positive) non-additivity the mixture phase separates into two fluid phases with different compositions. We calculate bulk fluid-fluid coexistence curves for a range of size ratios and non-additivity parameters and find that they compare well to simulation results from the literature. Using the Ornstein-Zernike equation, we investigate the asymptotic, r->infinity, decay of the partial pair correlation functions, g_ij(r). At low densities there occurs a structural crossover in the asymptotic decay between two different damped oscillatory modes with different wavelengths corresponding to the two intra-species hard core diameters. On approaching the fluid-fluid critical point there is Fisher-Widom crossover from exponentially damped oscillatory to monotonic asymptotic decay. Using the density functional we calculate the density profiles for the planar free fluid-fluid interface between coexisting fluid phases. We show that the type of asymptotic decay of g_ij(r) not only determines the asymptotic decay of the interface profiles, but is also relevant for intermediate and even short-ranged behaviour. We also determine the surface tension of the free fluid interface, finding that it increases with non-additivity, and that on approaching the critical point mean-field scaling holds.

  4. On using the beaming effect to measure spin-orbit alignment in stellar binaries with Sun-like components

    E-Print Network [OSTI]

    Shporer, Avi; Mazeh, Tsevi; Zucker, Shay

    2011-01-01T23:59:59.000Z

    The beaming effect (aka Doppler boosting) induces a variation in the observed flux of a luminous object, following its observed radial velocity variation. We describe a photometric signal induced by the beaming effect during eclipse of binary systems, where the stellar components are late type Sun-like stars. The shape of this signal is sensitive to the angle between the eclipsed star's spin axis and the orbital angular momentum axis, thereby allowing its measurement. We show that during eclipse there are in fact two effects, superimposed on the known eclipse light curve. One effect is produced by the rotation of the eclipsed star, and is the photometric analog of the spectroscopic Rossiter-McLaughlin effect, thereby it contains information about the sky-projected spin-orbit angle. The other effect is produced by the varying weighted difference, during eclipse, between the beaming signals of the two stars. We give approximated analytic expressions for the amplitudes of the two effects, and present a numerical...

  5. Rappels: 4) Piles Types abstraits de donnes (Abstract Data Type)

    E-Print Network [OSTI]

    Hamel, Sylvie

    Rappels: 4) Piles Types abstraits de donn茅es (Abstract Data Type) IFT2015, A2009, Sylvie Hamel Universit茅 de Montr茅al 1Piles Type de donn茅es Un ensemble de valeurs Un ensemble d'op茅rations Structure de Universit茅 de Montr茅al 2Piles Type abstrait de donn茅es PILE (搂4.2) Garde en m茅moire des objets arbitraires

  6. The Light Curve Variations of The Active Binaries With Hot Subdwarf Component

    E-Print Network [OSTI]

    Esin Sipahi; Serdar Evren

    2006-07-10T23:59:59.000Z

    We present the light curve variations of the two active binaries with hot subdwarf component. According to the brightness variations outside of the eclipses, the giant components of the systems are chromospherically active stars. The dark and cool active structures on this components cause the variations of the total light of the systems.

  7. Lifting Rationality Assumptions in Binary Aggregation Umberto Grandi and Ulle Endriss

    E-Print Network [OSTI]

    Endriss, Ulle

    Lifting Rationality Assumptions in Binary Aggregation Umberto Grandi and Ulle Endriss Institute aggregation procedure will lift the rationality assumptions from the in- dividual to the collective level, i an axiomatic characterisation of the class of aggregation proce- dures that will lift all rationality

  8. Computing Weight Distributions of Binary Linear Block Codes on a CCM ?

    E-Print Network [OSTI]

    Weinhardt, Markus

    Computing Weight Distributions of Binary Linear Block Codes on a CCM ? Markus Weinhardt Universit codes on an FPGA璪ased Custom Computing Machine (CCM). It consists of a heavily pipelined circuit plementation on a CCM, and section 4 reports on the performance of this im plementation. Finally, section 5

  9. SUPERORBITAL MODULATION OF X-RAY EMISSION FROM GAMMA-RAY BINARY LSI +61 303

    SciTech Connect (OSTI)

    Chernyakova, M. [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Neronov, A. [ISDC Data Center for Astrophysics, Chemin d'Ecogia 16, 1290 Versoix (Switzerland); Molkov, S.; Lutovinov, A. [Space Research Institute (IKI), 84/32 Profsoyuznaya Str., Moscow 117997 (Russian Federation); Malyshev, D. [Bogolyubov Institute for Theoretical Physics, 14-b Metrolohichna Street, Kiev 03680 (Ukraine); Pooley, G. [Astrophysics, Cavendish Laboratory, Cambridge CB3 0HE (United Kingdom)

    2012-03-10T23:59:59.000Z

    We report the discovery of a systematic constant time lag between the X-ray and radio flares of the gamma-ray binary LSI +61 303, persistent over a long, multi-year timescale. Using the data from the monitoring of the system by RXTE we show that the orbital phase of X-ray flares from the source varies from {phi}{sub X} {approx_equal} 0.35 to {phi}{sub X} {approx_equal} 0.75 on the superorbital 4.6 yr timescale. Simultaneous radio observations show that periodic radio flares always lag the X-ray flare by {Delta}{phi}{sub X-R} {approx_equal} 0.2. We propose that the constant phase lag corresponds to the time of flight of the high-energy particle-filled plasma blobs from inside the binary to the radio emission region at the distance of {approx}10 times the binary separation distance. We put forward a hypothesis that the X-ray bursts correspond to the moments of formation of plasma blobs inside the binary system.

  10. Short gamma-ray bursts from binary neutron star mergers in globular clusters

    E-Print Network [OSTI]

    Loss, Daniel

    ARTICLES Short gamma-ray bursts from binary neutron star mergers in globular clusters JONATHAN@cfa.harvard.edu Published online: 29 January 2006; doi:10.1038/nphys214 Observations by the Swift gamma-ray-burst (GRB, the so-called `long' GRBs (>2-200 s) were located by coded aperture imaging of their hard X-ray emission

  11. DEEP MULTI-TELESCOPE PHOTOMETRY OF NGC 5466. I. BLUE STRAGGLERS AND BINARY SYSTEMS

    SciTech Connect (OSTI)

    Beccari, G. [European Southern Observatory, Alonso de Cordova 3107, 19001 Santiago de Chile (Chile); Dalessandro, E.; Lanzoni, B.; Ferraro, F. R.; Miocchi, P. [Dipartimento di Fisica e Astronomia, Universit degli Studi di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Sollima, A.; Bellazzini, M., E-mail: gbeccari@eso.org [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)

    2013-10-10T23:59:59.000Z

    We present a detailed investigation of the radial distribution of blue straggler star (BSS) and binary populations in the Galactic globular cluster NGC 5466, over the entire extension of the system. We used a combination of data acquired with the Advanced Camera for Survey on board the Hubble Space Telescope, the LBC-blue mounted on the Large Binocular Telescope, and MEGACAM on the Canada-France-Hawaii Telescope. BSSs show a bimodal distribution with a mild central peak and a quite internal minimum. This feature is interpreted in terms of a relatively young dynamical age in the framework of the 'dynamical clock' concept proposed by Ferraro et al. The estimated fraction of binaries is ?6%-7% in the central region (r < 90'') and slightly lower (?5.5%) in the outskirts, at r > 200''. Quite interestingly, the comparison with the results of Milone et al. suggests that binary systems may also display a bimodal radial distribution, with the position of the minimum consistent with that of BSSs. If confirmed, this feature would give additional support to the scenario where the radial distribution of objects more massive than the average cluster stars is primarily shaped by the effect of dynamical friction. Moreover, this would also be consistent with the idea that the unperturbed evolution of primordial binaries could be the dominant BSS formation process in low-density environments.

  12. Blue Stragglers, Be stars and X-ray binaries in open clusters

    E-Print Network [OSTI]

    Amparo Marco; Ignacio Negueruela; Christian Motch

    2005-12-19T23:59:59.000Z

    Combination of high-precision photometry and spectroscopy allows the detailed study of the upper main sequence in open clusters. We are carrying out a comprehensive study of a number of clusters containing Be stars in order to evaluate the likelihood that a significant number of Be stars form through mass exchange in a binary. Our first results show that most young open clusters contain blue stragglers. In spite of the small number of clusters so far analysed, some trends are beginning to emerge. In younger open clusters, such as NGC 869 and NGC 663, there are many blue stragglers, most of which are not Be stars. In older clusters, such as IC 4725, the fraction of Be stars among blue stragglers is very high. Two Be blue stragglers are moderately strong X-ray sources, one of them being a confirmed X-ray binary. Such objects must have formed through binary evolution. We discuss the contribution of mass transfer in a close binary to the formation of both blue stragglers and Be stars

  13. Eddy Current Tomography Using a Binary Markov Mila Nikolova and Ali MohammadDjafari

    E-Print Network [OSTI]

    Nikolova, Mila

    Eddy Current Tomography Using a Binary Markov Model Mila Nikolova and Ali Mohammad and notches. The medium is illuminated with a monochromatic electric field; the anomalies induce eddy currents in various fields such as nuclear power plants and aerospace engineering. 1 #12; The objective of eddy

  14. Rao-Blackwellization for Bayesian Variable Selection and Model Averaging in Linear and Binary Regression

    E-Print Network [OSTI]

    West, Mike

    of covariates to use in regression or generalized linear models is a ubiquitous problem. The Bayesian paradigm regression and binary re- gression with non-orthogonal design matrices in conjunction with independent "spike and kernel regression (Clyde and George 2004). The generalization of the Gaussian linear model to other

  15. acetonitrile-water binary mixtures: Topics by E-print Network

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

    acetonitrile-water binary mixtures First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Sudden structural...

  16. Simulation of Stresses during Casting of Binary Magnesium-Aluminum Alloys

    E-Print Network [OSTI]

    Beckermann, Christoph

    Simulation of Stresses during Casting of Binary Magnesium-Aluminum Alloys M.G. POKORNY, C.A. MONROE made for aluminum alloys.[68] Recently, Mathier and co-workers[9,10] performed a detailed com- parison between measured and predicted forces in the mush during solidification of dilute aluminum alloys

  17. Timing the Kilohertz Quasi-Periodic Oscillations in Low-mass X-ray Binaries

    E-Print Network [OSTI]

    Mariano Mendez

    2000-06-19T23:59:59.000Z

    I describe a new technique that we have been using in the past few years to get precise measurements of the frequency separation of the kHz QPOs in some Low-mass X-ray binaries. I show how this technique (that we call "shift-and-add") works, and I present some of the results we obtained using it.

  18. Transient neutron star X-ray binaries with Simbol-X

    E-Print Network [OSTI]

    S. Campana

    2007-09-24T23:59:59.000Z

    We present a brief overview of test-bed observations on accreting neutron star binaries for the Simbol-X mission. We show that Simbol-X will provide unique observations able to disclose the physical mechanisms responsible for their high energy emission.

  19. Preferential Solvent Partitioning within Asphaltenic Aggregates Dissolved in Binary Solvent Mixtures

    E-Print Network [OSTI]

    Kilpatrick, Peter K.

    Preferential Solvent Partitioning within Asphaltenic Aggregates Dissolved in Binary SolventVised Manuscript ReceiVed December 9, 2006 The heaviest fraction of crude oils, asphaltenes, has been shown to play-assembled interfacially active asphaltenic aggregates. Thus, careful characterization of these aggregates is of great

  20. Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes Some otherwise chemically stable fluxes may decompose into suboxides in the presence of welding arcs, thereby providing higher levels of 0 2 in weld metal than those oxides which do not form suboxides ABSTRACT. The stability of metal

  1. Investigation of the highest occupied molecular orbital of propene by binary (e, 2e) spectroscopy

    E-Print Network [OSTI]

    Wang, Yayu

    shell binding energy spectra of propene with impact energies of 600 and 1200 eV by a binary (e, 2e momentum distributions calculated using Har- tree璅ock and density functional theory methods with various wave effects. 2004 Elsevier B.V. All rights reserved. 1. Introduction Electron momentum spectroscopy

  2. Blazars and the emerging AGN/black hole X-ray binary paradigm

    E-Print Network [OSTI]

    P. Uttley

    2005-08-02T23:59:59.000Z

    We briefly review the emerging paradigm which links the radio-quiet and radio-loud classes of AGN to the different accretion states observed in stellar mass black hole X-ray binary systems (BHXRBs), and discuss the relevance of the AGN/BHXRB connection to blazar variability.

  3. CS220 Spring 2014 Lab Assignment L3: Defusing a Binary Bomb

    E-Print Network [OSTI]

    Abu-Ghazaleh, Nael B.

    person for this lab. 1 Introduction The nefarious Dr. Evil has planted a slew of "binary bombs" on our machines (any of the machines in the G7 lab, or the LNG210 lab.) This includes the remote machines (remote you defuse your bomb. Please look at the hints section for some tips and ideas. The best way is to use

  4. Use of gravitational waves to measure alignment of spins in compact binaries

    E-Print Network [OSTI]

    Vitale, Salvatore; Graff, Philip; Sturani, Riccardo

    2015-01-01T23:59:59.000Z

    Coalescences of compact objects, neutron star and black holes, in binary systems are very promising sources of gravitational waves for the ground based detectors Advanced LIGO and Virgo. Much about compact binaries is still uncertain, including how often they are formed in the Universe, and some key details about their formation channels. One of the key open questions about compact binary coalescences is whether or not common envelope evolution is highly efficient in aligning spins with the orbital angular momentum. In this paper we show how gravitational waves detected by Advanced LIGO and Virgo can be used to verify if spins are preferentially aligned with the orbital angular momentum in compact binaries made of two black holes or a neutron star and a black hole. We first assume that all sources have either nearly aligned or non-aligned spins and use Bayesian model selection to calculate a cumulative odds ratio to compare the aligned and non-aligned models. We see that the correct model is typically preferr...

  5. Beam Test of a Large Area nonn Silicon Strip Detector with Fast Binary Readout Electronics

    E-Print Network [OSTI]

    Beam Test of a Large Area n璷n璶 Silicon Strip Detector with Fast Binary Readout Electronics Y test was carried out for the non璱rradiated and the irradiated detector modules. Efficiency, noise occupancy and performance in the edge regions were analyzed using the beam test data. High efficiency

  6. X-ray spectroscopy of low-mass X-ray binaries

    E-Print Network [OSTI]

    Juett, Adrienne Marie, 1976-

    2004-01-01T23:59:59.000Z

    I present high-resolution X-ray grating spectroscopy of neutron stars in low-mass X-ray binaries (LMXBs) using instruments onboard the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission (XMM-Newton). The first ...

  7. In vitro corrosion and biocompatibility of binary magnesium alloys Xuenan Gu a

    E-Print Network [OSTI]

    Zheng, Yufeng

    In vitro corrosion and biocompatibility of binary magnesium alloys Xuenan Gu a , Yufeng Zheng a Corrosion In vitro Cytotoxicity Hemocompatibility a b s t r a c t As bioabsorbable materials, magnesium was used as control. Their mechanical properties, corrosion properties and in vitro biocompatibilities

  8. Unaligned Binary Codes for Index Compression in Schema-Independent Text Retrieval Systems

    E-Print Network [OSTI]

    Waterloo, University of

    during index construction. Schema- independent indices have different characteristics than document unaligned codes. Thus, their more compact index represen- tation does not carry the cost of a substantiallyUnaligned Binary Codes for Index Compression in Schema-Independent Text Retrieval Systems Stefan B

  9. Advances in Electrical and Computer Engineering Abstract--The linear, binary, block codes with no equally

    E-Print Network [OSTI]

    Paris-Sud XI, Universit茅 de

    Advances in Electrical and Computer Engineering 1 Abstract-- The linear, binary, block codes block codes is proposed. These codes are seen as sources with memory and the information quantities H(S,X), H(S), H(X), H(X|S), H(S|X), I(S,X) are derived. On the base of these quantities, the code

  10. Beam Test of a Large Area nonn Silicon Strip Detector with Fast Binary Readout Electronics

    E-Print Network [OSTI]

    Beam Test of a Large Area n颅on颅n Silicon Strip Detector with Fast Binary Readout Electronics Y颅sided detector for the readout, its fabrication is similar to a double颅sided device, because the backside, which

  11. A Low-Power Correlation Detector For Binary FSK Direct-Conversion Receivers

    E-Print Network [OSTI]

    Arslan, H眉seyin

    A Low-Power Correlation Detector For Binary FSK Direct-Conversion Receivers J. Min, H-C. Liu, A detector, Tone detection, Correlation, Direct-conversion wireless receivers Abstract A multiplierless-suited for low-power direct-conversion receivers used in wireless communications systems employ- ing FSK

  12. Black-Box Identification for PLC based MPC of a Binary Distillation Column

    E-Print Network [OSTI]

    Black-Box Identification for PLC based MPC of a Binary Distillation Column B. Huyck ,, F. Logist J is to upgrade the control system with a linear MPC running on a PLC. However, before a model based controller can be used on a PLC, an accurate (but simple) process model has to be constructed. Hence, the aim

  13. Probability distribution function for inclinations of merging compact binaries detected by gravitational wave interferometers

    E-Print Network [OSTI]

    Naoki Seto

    2014-10-20T23:59:59.000Z

    We analytically discuss probability distribution function (PDF) for inclinations of merging compact binaries whose gravitational waves are coherently detected by a network of ground based interferometers. The PDF would be useful for studying prospects of (1) simultaneously detecting electromagnetic signals (such as gamma-ray-bursts) associated with binary mergers and (2) statistically constraining the related theoretical models from the actual observational data of multi-messenger astronomy. Our approach is similar to Schutz (2011), but we explicitly include the dependence of the polarization angles of the binaries, based on the concise formulation given in Cutler and Flanagan (1994). We find that the overall profiles of the PDFs are similar for any networks composed by the second generation detectors (Advanced-LIGO, Advanced-Virgo, KAGRA, LIGO-India). For example, 5.1% of detected binaries would have inclination angle less than 10 degree with at most 0.1% differences between the potential networks. A perturbative expression is also provided for generating the PDFs with a small number of parameters given by directional averages of the quantity $\\epsilon$ that characterises the asymmetry of network sensitivities to incoming two orthogonal polarization modes.

  14. Quantum mechanical method of fragment's angular and energy distribution calculation for binary and ternary fission

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V.; Pen'kov, N. V. [Voronezh State University (Russian Federation)

    2006-08-15T23:59:59.000Z

    In the framework of quantum-mechanical fission theory, the method of calculation for partial fission width amplitudes and asymptotic behavior of the fissile nucleus wave function with strong channel coupling taken into account has been suggested. The method allows one to solve the calculation problem of angular and energy distribution countation for binary and ternary fission.

  15. Evaluation of Hybrid Air-Cooled Flash/Binary Power Cycle

    SciTech Connect (OSTI)

    Greg Mines

    2005-10-01T23:59:59.000Z

    Geothermal binary power plants reject a significant portion of the heat removed from the geothermal fluid. Because of the relatively low temperature of the heat source (geothermal fluid), the performance of these plants is quite sensitive to the sink temperature to which heat is rejected. This is particularly true of air-cooled binary plants. Recent efforts by the geothermal industry have examined the potential to evaporatively cool the air entering the air-cooled condensers during the hotter portions of a summer day. While the work has shown the benefit of this concept, air-cooled binary plants are typically located in regions that lack an adequate supply of clean water for use in this evaporative cooling. In the work presented, this water issue is addressed by pre-flashing the geothermal fluid to produce a clean condensate that can be utilized during the hotter portions of the year to evaporatively cool the air. This study examines both the impact of this pre-flash on the performance of the binary plant, and the increase in power output due to the ability to incorporate an evaporative component to the heat rejection process.

  16. Simulator-analyzer for binary-cycle geothermal power plants: Volume 1, Executive summary: Final report

    SciTech Connect (OSTI)

    Greenlee, T.L.

    1987-04-01T23:59:59.000Z

    The object was to develop a generic dynamic simulator/analyzer for binary-cycle geothermal power plants for use on today's personal computers. The simulator/analyzer, as developed, can be used for (1) engineering analyses of static/dynamic performance and design trade-offs; (2) operator training and operating procedure evaluation; and (3) binary cycle technology demonstration. The simulator/analyzer consists of a set of ordinary non-linear differential equations that are programmed in a simulation language format and solved on an IBM-PC-AT. The equations are driven in an interactive mode by inputs from the PC keyboard and responses of plant temperatures, pressures, flows, etc., can be observed on a real-time color display that replicates a control room interface. Simulation predictions have been validated by comparisons with actual transient and steady state data taken from the Heber Binary Project, a 46.6 MWe binary-cycle demonstration power plant in operation in southern California. The simulation is accurate to within the uncertainty of the plant's process sensors. During this plant's later phases of construction, startup and operation, the simulator/analyzer is being used to: develop tuning constants for the Honeywell TDC-2000 control system, confirm failure/safety analyses study results, and support analyses of major operating events. It represents an adaptable tool for utilities and others involved in developing geothermal power generation facilities.

  17. ASIP-Based Multiprocessor SoC Design for Simple and Double Binary Turbo Decoding

    E-Print Network [OSTI]

    Muller, Olivier

    ASIP-Based Multiprocessor SoC Design for Simple and Double Binary Turbo Decoding Olivier Muller presents a new multiprocessor platform for high throughput turbo decoding. The proposed platform is based the recent shuffling technique introduced in the turbo-decoding field to reduce communication latency

  18. Tidal disruptions in circumbinary discs (I): Star formation, dynamics, and binary evolution

    E-Print Network [OSTI]

    Pau Amaro-Seoane; Patrick Brem; Jorge Cuadra

    2012-12-11T23:59:59.000Z

    In our current interpretation of the hierarchical structure of the universe it is well established that galaxies collide and merge with each other during their lifetime. If massive black holes (MBHs) reside in galactic centres, we expect them to form binaries in galactic nuclei surrounded by a circumbinary disc. If cooling is efficient enough, the gas in the disc will clump and trigger stellar formation in situ. In this first paper we address the evolution of the binary under the influence of the newly formed stars, which form individually and also clustered. We use SPH techniques to evolve the gas in the circumbinary disc and to study the phase of star formation. When the amount of gas in the disc is negligible, we further evolve the system with a high-accurate direct-summation $N-$body code to follow the evolution of the stars, the innermost binary and tidal disruption events (TDEs). For this, we modify the direct N-body code to (i) include treatment of TDEs and to (ii) include "gas cloud particles" that mimic the gas, so that the stellar clusters do not disolve when we follow their infall on to the MBHs. We find that the amount of stars disrupted by either infalling stellar clusters or individual stars is as large as 10^{-4}/yr per binary, higher than expected for typical galaxies.

  19. Binary inorganic salt mixtures as high conductivity liquid electrolytes for .100 uC fuel cells{

    E-Print Network [OSTI]

    Angell, C. Austen

    Binary inorganic salt mixtures as high conductivity liquid electrolytes for .100 uC fuel cells cations (e.g. ammonium) as electrolytes in fuel cells operating in the temperature range 100200 uC, where cell operating with optimized electrodes in the same temperature range, while open circuit voltages

  20. Henry's law, surface tension, and surface adsorption in dilute binary mixtures

    E-Print Network [OSTI]

    Henry's law, surface tension, and surface adsorption in dilute binary mixtures Akira Onukia. The solute partitioning between gas and liquid Henry's law and the surface tension change are discussed fraction X and the temperature-derivative / T cx,p of the surface tension at fixed pressure p