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Sample records for binary bx pegasi

  1. The Solar-Type Contact Binary BX Pegasi Revisited

    CERN Document Server

    Lee, Jae Woo; Lee, Chung-Uk; Youn, Jae-Hyuck

    2009-01-01

    We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on September 2008. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-time brightness disturbance. For these variations, model spots are applied separately to the two data set of Group I (Sep.--Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel-time (LTT) ...

  2. The Solar-Type Contact Binary BX Pegasi Revisited

    Science.gov (United States)

    Lee, Jae Woo; Kim, Seung-Lee; Lee, Chung-Uk; Youn, Jae-Hyuck

    2009-12-01

    We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on 2008 September. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-term brightness disturbance. For these variations, model spots are applied separately to the two data sets, Group I (Sep.-Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel time (LTT) effect due to the orbit of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body, or by the effect of magnetic activity with a cycle length of about 12 yr.

  3. Absolute properties of the binary system BB Pegasi

    CERN Document Server

    Kalomeni, B; Keskin, V; Degirmenci, O L; Ulas, B; Kose, O

    2007-01-01

    We present a ground based photometry of the low-temperature contact binary BB Peg. We collected all times of mid-eclipses available in literature and combined them with those obtained in this study. Analyses of the data indicate a period increase of 3.0(1) x 10^{-8} days/yr. This period increase of BB Peg can be interpreted in terms of the mass transfer 2.4 x 10^{-8} Ms yr^{-1} from the less massive to the more massive component. The physical parameters have been determined as Mc = 1.42 Ms, Mh = 0.53 Ms, Rc = 1.29 Rs, Rh = 0.83 Rs, Lc = 1.86 Ls, and Lh = 0.94 Ls through simultaneous solution of light and of the radial velocity curves. The orbital parameters of the third body, that orbits the contact system in an eccentric orbit, were obtained from the period variation analysis. The system is compared to the similar binaries in the Hertzsprung-Russell and Mass-Radius diagram.

  4. Four color light curves and period changes investigation of the contact binary BX Peg

    Science.gov (United States)

    Li, Kai; Hu, Shaoming; Guo, Difu; Jiang, Yunguo; Gao, Dongyang; Chen, Xu

    2015-11-01

    We presented BVRcIc light curves of BX Peg obtained by the Weihai Observatory 1.0-m telescope of Shandong University. The W-D code was used to analyze the four color light curves, it is shown that BX Peg is a W-subtype shallow contact binary with a fill-out factor of f = 14.6 % . The asymmetric light curves were explained by a dark spot on the less massive hot component. A total of 328 times of minimum light were used to study the orbital period variation of BX Peg. We found that the orbital period of BX Peg was continuous decrease with a rate of dp / dt = - 2.07 ×10-7 d yr-1 superimposed on a cyclic oscillation with a period of 57.8 yr. The secular period decrease should be caused by the angular momentum loss via magnetic stellar wind. The cyclic modulation is very likely to be produced by the light travel time effect due to a tertiary companion.

  5. Doppler images of the RS CVn binary II Pegasi during the years 1994-2002

    CERN Document Server

    Lindborg,; Korpi,; J., M; Hackman,; T.,; Tuominen,; I.,; Ilyin,; I.,; Piskunov,; N,

    2010-01-01

    We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes. The observations were collected with the SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. During 1994-2001, our results show a consistent trend in the derived longitudes of the principal and secondary temperature minima over time such that the magnetic structure appears to rotate somewhat more rapidly than the orbital period of this close binary. A sudden phase jump of the active region occured between the observing seasons of 2001 and 2002. No clear trend over time is detected in the derived latitudes of the spots, indicating that the syste...

  6. V421 Pegasi: a detached eclipsing binary with a possible γ Doradus component

    Science.gov (United States)

    Özdarcan, O.; Çakırlı, Ö.; Akan, C.

    2016-07-01

    We present spectroscopic and photometric study of V421 Peg. This eclipsing binary displays lines from both components that are well separated. This allowed us to classify the primary and secondary component as F(1 ± 0.5) V and F(2 ± 0.5) V, respectively. We use our radial velocity measurements together with Hipparcos and ASAS photometry and apply simultaneous analysis, which yields masses and radii of the primary and secondary components as M1 = 1.594 ± 0.029 M⊙, M2 = 1.356 ± 0.029 M⊙ and R1 = 1.584 ± 0.028 R⊙, R2 = 1.328 ± 0.029 R⊙, respectively. Positions of the components in HR diagram suggest that the primary component is a γ Doradus variable candidate. Spectroscopic and photometric properties of the system indicates reddening value of E(B - V) = 0m.021 which puts the system to the distance of 158 ± 4 pc.

  7. A PERIOD INVESTIGATION OF THE SX PHOENICIS STAR DY PEGASI

    International Nuclear Information System (INIS)

    We measure two new times of light maximum of the SX Phoenicis star DY Pegasi in 2008 December and collect 410 pe/CCD times of light maximum that had been published. These data could be modeled with a nonlinear fit including a continuously decreasing period change (dP/dt = -9.04 x 10-12 days day-1) and a periodic change with a period of 42.2 yr. If this periodic change is caused by the light traveling time effect of an orbital motion of DY Pegasi in a binary system, the deduced mass of the companion could be 0.028 Msun and it is probably a brown dwarf.

  8. Starspot evolution, differential rotation, and magnetic cycles in the chromospherically active binaries lambda andromedae, sigma Geminorum, II Pegasi, and V711 Tauri

    Science.gov (United States)

    Henry, Gregory W.; Eaton, Joel A.; Hamer, Jamesia; Hall, Douglas S.

    1995-01-01

    We have analyzed 15-19 yr of photoelectric photometry, obtained manually and with automated telescopes, of the chromospherically active binaries lambda And, sigma Gem, II Peg, and V711 Tau. These observations let us identify individual dark starspots on the stellar surfaces from periodic dimming of the starlight, follow the evolution of these spots, and search for long-term cyclic changes in the properties of these starspots that might reveal magnetic cycles analogous to the Sun's 11 yr sunspot cycle. We developed a computer code to fit a simple two-spot model to our observed light curves that allows us to extract the most easily determinable and most reliable spot parameters from the light curves, i.e., spot longitudes and radii. We then used these measured properties to identify individual spots and to chart their life histories by constructing migration and amplitude curves. We identified and followed 11 spots in lambda And, 16 in sigma Gem, 12 in II Peg, and 15 in V711 Tau. Lifetimes of individual spots ranged from a few months to longer than 6 yr. Differential rotation coefficients, estimated from the observed range of spot rotation periods for each star and defined by equation (2), were 0.04 for lambda And, 0.038 for sigma Gem, 0.005 for II Peg, and 0.006 for V711 Tau, versus 0.19 for the Sun. We searched for cyclic changes in mean brightness, B-V color index, and spot rotation period as evidence for long-term cycles. Of these, long-term variability in mean brightness appears to offer the best evidence for such cycles in these four stars. Cycles of 11.1 yr for lambda And, 8.5 yr for sigma Gem, 11 yr for II Peg, and 16 yr V711 Tau are implied by these mean brightness changes. Cyclic changes in spot rotation period were found in lambda And and possibly II Peg. Errors in B-V were too large for any long-term changes to be detectable.

  9. Analysis of the symbiotic star AG Pegasi

    Science.gov (United States)

    Keyes, C. D.; Plavec, M. J.

    1981-01-01

    High and low dispersion IUE data are analyzed in conjunction with coincident ground based spectrophotometric scans and supplementary infrared photometry of the symbiotic object AG Pegasi. The IUE observations yield an improved value of E(B-V) = 0.12. The two stellar components are easily recognized in the spectra. The cool component may be an M1.7 III star and the hot component appears to have T (sub eff) of approximately 30000 K. The emission lines observed in the ultraviolet indicate two or three distince emitting regions. Nebular component ultraviolet intercombination lines suggest an electron density of several times 10 billion/cu cm.

  10. Starspots on LO Pegasi, 2006-2015

    Science.gov (United States)

    Harmon, Robert O.; Chalmers, Mark; Geda, Robel; Henry, Brandi; Sliupas, Viesulas

    2016-01-01

    LO Pegasi is a rapidly rotating (P = 10.154 hr) young solar analog (spectral class K5-7V) variable star of BY Dra type that exhibits dark starspots on its surface that modulate its brightness as they are carried into and out of view by the star's rotation. Surface maps of the spot distribution were produced based on BVRI photometry obtained at Perkins Observatory from 2006-2015. The maps were generated from the light curves via a non-linear inversion algorithm that uses the differences in the limb darkening through different filter passbands to improve the latitude resolution of the maps. We present an analysis of variations in the size of a polar spot suggested by changes in the average brightness and the amplitude of the rotational modulation from year to year.

  11. Youth plus experience: the discovery of 51 Pegasi b

    Science.gov (United States)

    Cenadelli, Davide; Bernagozzi, Andrea

    2015-12-01

    In 1995, Michel Mayor and Didier Queloz announced they discovered 51 Pegasi b, the first planet ever found around a star other than the Sun. This discovery turned out to be a milestone of recent astronomy, as it opened up a new field of research that is growing impressively these days. However, 51 Pegasi b has surprising properties as compared to the planets of the Solar System, as it is a giant planet on a very close-in orbit around its parent star. Hence, its discovery was unexpected and its actual existence did not go unchallenged. In the following years, a passionate debate sprang up, and finally astronomers accepted it, but at the price of a deep revision of our understanding of how planetary systems are formed and evolve. In the present paper, we reconstruct the dynamics of the discovery of 51 Pegasi b and the first exoplanets, the quarrel that arose among astronomers and the final acceptance of the existence of planets with unexpected characteristics. This remarkable story is recounted by means of published literature as well as interviews with several of its main protagonists.

  12. AG Pegasi - now a classical symbiotic star in outburst?

    Science.gov (United States)

    Tomov, T. V.; Stoyanov, K. A.; Zamanov, R. K.

    2016-11-01

    Optical spectroscopy study of the recent AG Pegasi (AG Peg) outburst observed during the second half of 2015 is presented. Considerable variations of the intensity and the shape of the spectral features as well as the changes of the hot component parameters, caused by the outburst, are discussed and certain similarities between the outburst of AG Peg and the outburst of a classical symbiotic stars are shown. It seems that after the end of the symbiotic nova phase, AG Peg became a member of the classical symbiotic stars group.

  13. X-Ray Spectroscopy of II Pegasi Coronal Temperature Structure, Abundances, and Variability

    CERN Document Server

    Huenemoerder, D P; Schulz, N S; Huenemoerder, David P.; Canizares, Claude R.; Schulz, Norbert S.

    2001-01-01

    We have obtained high resolution X-ray spectra of the coronally active binary, II Pegasi (HD 224085), covering the wavelength range of 1.5-25 Angstroms. For the first half of our 44 ksec observation, the source was in a quiescent state with constant X-ray flux, after which it flared, reaching twice the quiescent flux in 12 ksec, then decreasing. We analyze the emission-line spectrum and continuum during quiescent and flaring states. The differential emission measure derived from lines fluxes shows a hot corona with a continuous distribution in temperature. During the non-flare state, the distribution peaks near log T = 7.2, and when flaring, near 7.6. High-temperature lines are enhanced slightly during the flare, but most of the change occurs in the continuum. Coronal abundance anomalies are apparent, with iron very deficient relative to oxygen and significantly weaker than expected from photospheric measurements, while neon is enhanced relative to oxygen. We find no evidence of appreciable resonant scatterin...

  14. The magnetic field of the B3V star 16 Pegasi

    NARCIS (Netherlands)

    H.F. Henrichs; C. Neiner; R.S. Schnerr; E. Verdugo; A. Alecian; C. Catala; F. Cochard; J. Gutiérrez; A.L. Huat; J. Silvester; O. Thizy

    2008-01-01

    The slowly pulsating B3V star 16 Pegasi was discovered by Hubrig et al. (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France a

  15. Waves In Accretion Disks, Observed With Fresno State'S Station At Sierra Remote Observatories: Hv Andromedae, Lq Pegasi, And Ln Ursae Majoris

    Science.gov (United States)

    Rude, Gerald; Ringwald, F. A.

    2012-01-01

    We present observations of three cataclysmic variable stars: HV Andromedae, LQ Pegasi, and LN Ursae Majoris. A cataclysmic variable star is a binary star system composed of a red dwarf orbiting a white dwarf. These stars orbit closely, typically in 3-4 hours. Due to this close orbit, gas spills from the red dwarf into orbit around the white dwarf. This forms an accretion disk. Accretion disks are found throughout the Universe: from planetary formation, Saturn's rings, black holes that swallow stars, to the Milky Way's spiral structure. Our goal in studying these three cataclysmic variables was to search for evidence of waves, warping, or bending of their accretion disks. Photometry is the study of how the brightness of an object changes over time. With cataclysmic variables much of the fluctuation in brightness is from the accretion disk. We collected time-resolved differential photometry of three cataclysmic variables using Fresno State's remotely controlled telescope at Sierra Remote Observatories. After measuring our photometry, we searched for waves in the data. We have surprising results for each of the stars studied. All of these objects have prominent low-frequency periodicities not seen in the literature. This can be attributed to Fresno State's Remote Observatory's ability to observe stars for extended periods of time. We found strong evidence for both warping and bending waves in LQ Pegasi. In LN Ursae Majoris, we discovered apparently chaotic behavior, with the low-frequency wave changing significantly in just under a month. We also see clear evidence for short-period waves in HV Andromedae, also with some rumbling at low frequencies. Our observations of these three cataclysmic variables, especially of LN Ursae Majoris, warrant further study in the form of radial-velocity studies.

  16. A Follow-up Study for Chinese Chronic Hepatitis C Patients Treated with the Combination of PEG-IFNα-2a (PEGASYS) and Ribavirin

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Objective To compare the efifcacy of peginterferon alfa-2a (PEGASYS) plus ribavirin (RBV) with interferon alfa-2a plus RBV, and evaluate the safety. Methods Total of 117 patients with chronic hepatitis C were enrolled to receive either PEGASYS (135 μg or 180 μg) subcutaneously once per week, plus RBV (800 mg-1 200 mg) per day for 48 weeks (79 patients, PEGASYS group), or 5 million units of interferon alfa-2a subcutaneously every other day, plus RBV as above dosage for 48 weeks (38 patients, IFNα group). Results Sixty-three of 79 (79.7%) patients reached sustained virological response (SVR) in PEGASYS group, while 14 of 38 (36.8%) patients reached SVR in IFNα group. PEGASYS group was associated with a higher rate of virologic response than IFNα group at week 4, 12, 36, 48 and week 72. Sustained normalization of serum ALT concentrations at week 36, 48 and week 72 was also more common in PEGASYS group than in IFNα group. Baseline levels of ALT and HCV RNA had no effect on SVR in either PEGASYS group or IFNαgroup. Both groups were similar in the frequency and severity of adverse events. Conclusions PEGASYS plus RBV produced similar adverse events but higher rate of SVR. Meanwhile, complications should be prevented and treated promptly in order to increase compliances and effects.

  17. Tank 241-BX-103 tank characterization plan

    Energy Technology Data Exchange (ETDEWEB)

    Bell, K.E. [Westinghouse Hanford Co., Richland, WA (United States)

    1995-04-21

    This document is a plan which serves as the contractual agreement between the Characterization Program, Sampling Operations, and WHC 222-S Laboratory. The scope of this plan is to provide guidance for the sampling and analysis of samples for tank 241-BX-103.

  18. The active RS Canum Venaticorum binary II Pegasi. IV. The SPOT activity cycle

    Science.gov (United States)

    Berdyugina, S. V.; Berdyugin, A. V.; Ilyin, I.; Tuominen, I.

    1999-10-01

    A total of 6 new surface images of II Peg obtained for the years 1997 and 1998 confirms the recently revealed permanent active longitude structure. The lower limit of the active longitudes' lifetime is now extended up to 25 years. A new ``flip-flop'' phenomenon, redefined as a switch of the activity between the active longitudes, has started in summer of 1998. It coincides reasonably well with the moment predicted from the activity cycle of the star. This confirms definitely the cyclic behaviour of the activity of II Peg we recently discovered. Therefore, we assign numbers to the cycles of 4.65 yr since the earliest photoelectric observations of II Peg and define the active longitudes as ``odd'' and ``even'' corresponding to odd and even numbers of cycles. With such a definition, in late 1998 the 7th cycle began and the ``odd'' active longitude became more active. From the analysis of the spot area evolution within the active longitudes we conclude that the activity cycle is developed as a rearrangement of the nearly constant amount of the spot area between the active longitudes. We discuss the ``flip-flop'' phenomenon as a tracer of stellar activity and the role of the unseen secondary in establishing the cycle. Based on observations collected at the Nordic Optical Telescope (NOT), La Palma, Spain; the 1.25m telescope of the Crimean Astrophysical Observatory, Ukraine; the Phoenix 10 robotic telescope, APT Observatory, Arizona, USA.}

  19. The magnetic field of the B3V star 16 Pegasi

    OpenAIRE

    Henrichs, H. F.; Neiner, C.; Schnerr, R. S.; Verdugo, E.; Alecian, A.; Catala, C.; Cochard, F.; Gutiérrez, J.; Huat, A. -L.; Silvester, J.; Thizy, O.

    2008-01-01

    The Slowly Pulsating B3V star 16 Pegasi was discovered by Hubrig (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France and Espadons at CFHT, Hawaii during 2007. The most likely period is about 1.44 d for the modulation of the field, but this could not be firmly established with the available data set. No variability has be...

  20. Complex asteroseismology of the hybrid B-type pulsator $\\gamma$ Pegasi: a test of stellar opacities

    CERN Document Server

    Walczak, Przemysław

    2010-01-01

    Using the updated oscillation spectrum of $\\gamma$ Pegasi, we construct a set of seismic models which reproduce two pulsational frequencies corresponding to the $\\ell=0$, p$_1$ and $\\ell=1$, g$_1$ modes. Then, we single out models which reproduce other well identified modes. Finally, we extend our seismic modelling by a requirement of fitting also values of the complex, nonadiabatic parameter $f$ associated to each mode frequency. Such complex asteroseismology of the B-type pulsators provides a unique test of stellar metallicity and opacities. In contrast to our previous studies, results for $\\gamma$ Peg indicate that both opacity tables, OPAL and OP, are equally preferred.

  1. Three years of photometry of IM Pegasi = HR 8703

    Science.gov (United States)

    Eaton, J. A.; Hall, D. S.; Henry, G. W.; Lovell, L. P.; Stephan, C. A.; Chambliss, C. R.; Detterline, P. K.; Landis, H. J.; Louth, H.; Renner, T. R.

    1983-01-01

    Differential photometry of this K1 IV-III p RS CVn-type binary in 1978-79, 1979-80, and 1980-81 at eight different observatories shows that the variability, discovered originally by Herbst, is periodic. The mean of three different determinations of the photometric period was 24(d).39 + or 0(d).03, about 1 percent shorter than the orbital period of 24(d).649 determined spectroscopically by Harper. The total range observed during these three years was for V from 5(m).60 to 5(m).85. The light curve was nearly sinusoidal but always noticieably asymmetric, with the sense reversing sometime between 1979-80 and 1980-81.

  2. 无线传感器网络PEGASIS协议的研究%PEGASIS Protocol for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    李舒颜; 李腊元

    2012-01-01

    为建立一个高效节能的路由环境,在分析PEGASIS( power-efficient gathering in sensor information system)的基础上,对PEGASIS算法进行了改进.将整个传感器区域划分为等宽的子区间,由每个区间内距离Sink最近的节点建立主链,然后在每个区域内建立链树,再由主链节点轮流担任根节点与Sink通信,以减少通信开销.模拟实验表明,算法在生存时间、能耗均衡等方面的性能较PEGASIS有明显提高.%Formulation of energy efficient protocols is of utmost importance for wireless sensor network ( WSN ) because of energy constraints of sensor nodes. PEGASIS (power - efficient gathering in sensor information system) is one of low energy algorithms for wireless sensor networks. The modified PEGASIS algorithm was proposed. The sensor area was divided into several areas of the same width. Then the proximate node from sink in every area was figured out to establish the main chain. The nodes on the main chain communicate to sink as the root node by turns. This method enhances network performances by reducing the transmission energy. Simulation results show that the improved algorithm has a higher efficiency of energy utilization.

  3. Chemical abundance analysis of symbiotic giants. RW Hya, SY Mus, BX Mon, and AE Ara

    CERN Document Server

    Galan, Cezary; Hinkle, Kenneth H; Schmidt, Miroslaw R; Gromadzki, Mariusz

    2014-01-01

    Symbiotic stars are the long period, binary systems of strongly interacting stars at the final stages of evolution which can be useful tool to understand the chemical evolution of the Galaxy and the formation of stellar populations. Knowledge of the chemical composition of the symbiotic giants is essential to advancing our understanding of these issues but unfortunately reliably determinations exist only in a few cases. We perform a program for detailed chemical composition analysis in over 30 symbiotic giants, based on the high resolution, near-IR spectra, obtained with Phoenix/Gemini South spectrometer. The methods of the standard LTE analysis is used to obtain photospheric abundances of CNO and elements around iron peak. Here we present results obtained for four objects: RW Hya, SY Mus, BX Mon, and AE Ara. Our analysis revealed a significantly sub-solar metallicity (Me/H ~ -0.75) for RW Hya, a slightly sub-solar metallicities (Me/H ~ 0.2-0.3) in BX Mon and AE Ara, and a near-solar metallicity in SY Mus. 12...

  4. Detection of molecular absorption in the dayside of exoplanet 51 Pegasi b?

    CERN Document Server

    Brogi, M; de Kok, R J; Albrecht, S; Birkby, J L; de Mooij, E J W

    2013-01-01

    In this paper we present ground-based high-resolution spectroscopy of 51 Pegasi using CRIRES at the Very Large Telescope. The system was observed for 3x5 hours at 2.3 {\\mu}m at a spectral resolution of R = 100,000, targeting potential signatures from carbon monoxide, water vapour and methane in the planet's dayside spectrum. In the first 2x5 hours of data, we find a combined signal from carbon monoxide and water in absorption at a formal 5.9{\\sigma} confidence level, indicating a non-inverted atmosphere. We derive a planet mass of M_P = (0.46 +- 0.02) M_Jup and an orbital inclination i between 79.6 and 82.2 degrees, with the upper limit set by the non-detection of the planet transit in previous photometric monitoring. However, there is no trace of the signal in the final 5 hours of data. A statistical analysis indicates that the signal from the first two nights is robust, but we find no compelling explanation for its absence in the final night. The latter suffers from stronger noise residuals and greater inst...

  5. Spectral mapping of the spiral structures in IP Pegasi on the decline from an outburst

    CERN Document Server

    Baptista, R; Thomas, G; Baptista, Raymundo; Haswell, Carole A.; Thomas, Gino

    2002-01-01

    (abridged) We report eclipse mapping of time resolved spectroscopy of the dwarf nova IP Pegasi on the late decline from the May 1993 outburst. The spiral arms are still visible some 8 days after the onset of the outburst. Their fractional contribution to the continuum emission is similar to that measured close to outburst maximum, whereas their orientation is rotated by 58 degrees with respect to the spirals seen in the eclipse map at outburst maximum. Velocity-resolved light curves across the Halpha and the HeI lines show the classical rotational disturbance, with the blue side of the line being eclipsed earlier than the red side. The differences between the Halpha and the HeI maps are significant. The spiral arms are clearly seen in the HeI maps, with the receding arm being stronger in the red side while the approaching arm is stronger in the blue side of the line. The analysis of the Halpha maps suggests that this emission arises mainly from a large and vertically-extended region which we interpret as an o...

  6. Roche tomography of cataclysmic variables - V. A high-latitude star-spot on RU Pegasi

    CERN Document Server

    Dunford, Alexander; Smith, Robert Connon

    2012-01-01

    We present Roche tomograms of the secondary star in the dwarf nova system RU Pegasi derived from blue and red arm ISIS data taken on the 4.2-m William Herschel Telescope. We have applied the entropy landscape technique to determine the system parameters and obtained component masses of M1 = 1.06 Msun, M2 = 0.96 Msun, an orbital inclination angle of i = 43 degrees, and an optimal systemic velocity of gamma = 7 km/s. These are in good agreement with previously published values. Our Roche tomograms of the secondary star show prominent irradiation of the inner Lagrangian point due to illumination by the disc and/or bright spot, which may have been enhanced as RU Peg was in outburst at the time of our observations.We find that this irradiation pattern is axi-symmetric and confined to regions of the star which have a direct view of the accretion regions. This is in contrast to previous attempts to map RU Peg which suggested that the irradiation pattern was non-symmetric and extended beyond the terminator. We also d...

  7. A Light Curve And Period Analysis Of AE Ursae Majoris, CY Aquarii, And DY Pegasi

    Science.gov (United States)

    Joner, Michael D.; Iverson, E. P.; Jolley, J. W.; Joner, L. A.; Swenson, C. A.

    2007-12-01

    We present a light curve analysis of three high amplitude delta Scuti stars (HADs). Data for this presentation were all secured during spring and fall of 2007. Most of the observations were obtained using the facilities of the Brigham Young University West Mountain Observatory. The variable stars we observed in this investigation include AE Ursae Majoris, CY Aquarii, and DY Pegasi. We present evidence for small period changes as well as an analysis of the light curve components for each of the variables. We compare the results obtained in the present investigation with prior studies of these same targets. This investigation is part of an initiative to provide a mentored learning environment at the West Mountain Observatory and to promote a variety of undergraduate research experiences. Tools developed in this investigation include the data reduction procedures that enable us to process the several thousand CCD frames that are secured each night as raw observations. We thank the Department of Physics and Astronomy and the College of Physical and Mathematical Sciences at Brigham Young University for the continued support of mentored undergraduate research.

  8. 77 FR 14843 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2012-03-13

    ... of Proposed Rule Change To Modify Pricing for BX Members Using the NASDAQ OMX BX Equities System... order routing strategy. BX will implement the proposed change immediately on March 1, 2012. The text of... modify its fees for orders that are routed using BX's BTFY order routing strategy. BTFY is a...

  9. Low-temperature sequential pulsed chemical vapor deposition of ternary BxGa1-xN and BxIn1-xN thin film alloys

    International Nuclear Information System (INIS)

    In this work, the authors have performed sequential pulsed chemical vapor deposition of ternary BxGa1-xN and BxIn1-xN alloys at a growth temperature of 450 °C. Triethylboron, triethylgallium, trimethylindium, and N2 or N2/H2 plasma have been utilized as boron, gallium, indium, and nitrogen precursors, respectively. The authors have studied the compositional dependence of structural, optical, and morphological properties of BxGa1-xN and BxIn1-xN ternary thin film alloys. Grazing incidence X-ray diffraction measurements showed that boron incorporation in wurtzite lattice of GaN and InN diminishes the crystallinity of BxGa1-xN and BxIn1-xN sample. Refractive index decreased from 2.24 to 1.65 as the B concentration of BxGa1-xN increased from 35% to 88%. Similarly, refractive index of BxIn1-xN changed from 1.98 to 1.74 for increase in B concentration value from 32% to 87%, respectively. Optical transmission band edge values of the BxGa1-xN and BxIn1-xN films shifted to lower wavelengths with increasing boron content, indicating the tunability of energy band gap with alloy composition. Atomic force microscopy measurements revealed an increase in surface roughness with boron concentration of BxGa1-xN, while an opposite trend was observed for BxIn1-xN thin films

  10. Geometry of BxB-orbit closures in equivariant embeddings

    DEFF Research Database (Denmark)

    He, X.; Thomsen, Jesper Funch

    2005-01-01

    Let X denote an equivariant embedding of a connected reductive group G over an algebraically closed field k. Let B denote a Borel subgroup of G and let Z denote a BxB-orbit closure in X. When the characteristic of k is positive and X is projective we prove that Z is globally F-regular. As a conse...

  11. Tank characterization report for single-shell tank 241-BX-107

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, G.F.

    1996-02-28

    This study examined and assessed the status, safety issues, composition, and distribution of the wastes contained in the tank 241-BX-107. Historical and most recent information, ranging from engineering structural assessment experiments, process history, monitoring and remediation activities, to analytical core sample data, were compiled and interpreted in an effort to develop a realistic, contemporary profile for the tank BX-107 contents.

  12. 75 FR 1436 - Self-Regulatory Organizations; NASDAQ OMX BX; Notice of Filing and Immediate Effectiveness of a...

    Science.gov (United States)

    2010-01-11

    ... services, including the collection of annual membership fees from BX members pursuant to BX Rule 7001(a). BOX participants are not subject to the BX annual membership fee. Due to a limitation with FINRA's... proposing to allow FINRA to deduct an annual $3,000 membership fee from Boston Options Exchange Group,...

  13. Two-dimensional BX (X = P, As, Sb) semiconductors with mobilities approaching graphene

    Science.gov (United States)

    Xie, Meiqiu; Zhang, Shengli; Cai, Bo; Zhu, Zhen; Zou, Yousheng; Zeng, Haibo

    2016-07-01

    Carrier mobility plays a key role in the performance of microelectronic devices, especially the field effect transistors (FET). To design next generation two-dimensional (2D) FET, stable channel materials with a higher carrier mobility than silicon and a significant band gap are highly desirable, but are still not discovered. Here, we report a group of 2D materials of BX (X = P, As, and Sb), which are semiconducting with an ultrahigh carrier mobility. Using first-principles calculations, we find that all BX configurations are similar to graphene, but possess direct bandgaps of 1.36, 1.14, and 0.49 eV, respectively. Based on deformation potential theory, BX monolayers are predicted to have superior mobilities (>104 cm2 V-1 s-1) to phosphorene. In particular, the electron mobility of monolayer BSb is 3.2 × 105 cm2 V-1 s-1, approaching the figure of merit in graphene (~3 × 105 cm2 V-1 s-1). These results demonstrate that BX monolayers are of paramount significance for next-generation 2D FET manufacture.Carrier mobility plays a key role in the performance of microelectronic devices, especially the field effect transistors (FET). To design next generation two-dimensional (2D) FET, stable channel materials with a higher carrier mobility than silicon and a significant band gap are highly desirable, but are still not discovered. Here, we report a group of 2D materials of BX (X = P, As, and Sb), which are semiconducting with an ultrahigh carrier mobility. Using first-principles calculations, we find that all BX configurations are similar to graphene, but possess direct bandgaps of 1.36, 1.14, and 0.49 eV, respectively. Based on deformation potential theory, BX monolayers are predicted to have superior mobilities (>104 cm2 V-1 s-1) to phosphorene. In particular, the electron mobility of monolayer BSb is 3.2 × 105 cm2 V-1 s-1, approaching the figure of merit in graphene (~3 × 105 cm2 V-1 s-1). These results demonstrate that BX monolayers are of paramount significance for

  14. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  15. The slowly pulsating B-star 18 Pegasi: A testbed for upper main sequence stellar evolution

    Science.gov (United States)

    Irrgang, A.; Desphande, A.; Moehler, S.; Mugrauer, M.; Janousch, D.

    2016-06-01

    The predicted width of the upper main sequence in stellar evolution models depends on the empirical calibration of the convective overshooting parameter. Despite decades of discussions, its precise value is still unknown and further observational constraints are required to gauge it. Based on a photometric and preliminary asteroseismic analysis, we show that the mid B-type giant 18 Peg is one of the most evolved members of the rare class of slowly pulsating B-stars and, thus, bears tremendous potential to derive a tight lower limit for the width of the upper main sequence. In addition, 18 Peg turns out to be part of a single-lined spectroscopic binary system with an eccentric orbit that is greater than 6 years. Further spectroscopic and photometric monitoring and a sophisticated asteroseismic investigation are required to exploit the full potential of this star as a benchmark object for stellar evolution theory. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 265.C-5038(A), 069.C-0263(A), and 073.D-0024(A). Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC), proposals H2005-2.2-016 and H2015-3.5-008. Based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, proposal W15BN015. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.

  16. Time-series Doppler images and surface differential rotation of the effectively-single rapidly-rotating K-giant KU Pegasi

    CERN Document Server

    Kővári, Zs; Strassmeier, K G; Carroll, T A; Weber, M; Kriskovics, L; Oláh, K; Vida, K; Granzer, T

    2016-01-01

    According to most stellar dynamo theories, differential rotation (DR) plays a crucial role for the generation of toroidal magnetic fields. Numerical models predict surface differential rotation to be anti-solar for rapidly-rotating giant stars, i.e., their surface angular velocity could increase with stellar latitude. However, surface differential rotation has been derived only for a handful of individual giant stars to date. The spotted surface of the K-giant KU Pegasi is investigated in order to detect its time evolution and quantify surface differential rotation. We present altogether 11 Doppler images from spectroscopic data collected with the robotic telescope STELLA between 2006--2011. All maps are obtained with the surface reconstruction code iMap. Differential rotation is extracted from these images by detecting systematic (latitude-dependent) spot displacements. We apply a cross-correlation technique to find the best differential rotation law. The surface of KU Peg shows cool spots at all latitudes a...

  17. K/BxN serum transfer arthritis as a model for human inflammatory arthritis

    Directory of Open Access Journals (Sweden)

    Anne Deen Christensen

    2016-06-01

    Full Text Available The K/BxN serum-transfer arthritis (STA model is a murine model in which the immunological mechanisms occurring in rheumatoid arthritis (RA and other arthritides can be studied. To induce K/BxN STA, serum from arthritic transgenic K/BxN mice is transferred to naive mice and manifestations of arthritis occur a few days later. The inflammatory response in the model is driven by autoantibodies against the ubiquitously expressed self-antigen, glucose-6-phosphate isomerase (G6PI, leading to the formation of immune complexes that drive the activation of different innate immune cells such as neutrophils, macrophages and possibly mast cells. The pathogenesis further involves a range of immune mediators including cytokines, chemokines, complement factors, Toll-like receptors, Fc receptors, and integrins, as well as factors involved in pain and bone erosion. Hence, even though the K/BxN STA model mimics only the effector phase of RA, it still involves a wide range of relevant disease mediators. Additionally, as a murine model for arthritis, the K/BxN STA model has some obvious advantages. Firstly, it has a rapid and robust onset of arthritis with 100% incidence in genetically identical animals. Secondly, it can be induced in a wide range of strain backgrounds and can therefore also be induced in gene-deficient strains to study the specific importance of disease mediators. Even though G6PI might not be an essential autoantigen, for example, in RA, the K/BxN STA model is a useful tool to understand how autoantibodies in general drive the progression of arthritis by interacting with downstream components of the innate immune system. Finally, the model has also proven useful as a model wherein arthritic pain can be studied. Taken together, these features make the K/BxN STA model a relevant one for RA and it is a potentially valuable tool especially for the pre-clinical screening of new therapeutic targets for RA and perhaps other forms of inflammatory

  18. The band structures of BSb and BxGa1-xSb alloys

    Institute of Scientific and Technical Information of China (English)

    XIONG DePing; ZHOU ShouLi; WANG Qi; LUO Li; HUANG YongQing; REN XiaoMin

    2009-01-01

    The band structures of BSb and BxGa1-xSb alloys are studied using first-principles calculations in the generalized gradient approximation. By SQS-8 supercells to model a random alloy, the direct transition energy-gap (Γ15v-Γ1c) bowing of 3.0 eV is obtained for BxGa1-xSb alloys in x=0-50%, in x=0-11% the energy-gap is the band-gap and increases by 7 meV/%B with boron composition increasing; by SQS-16 supercells the bowing parameter is about 1.9 eV in x= 0-12.5%. The formation enthalpies of mixing, ΔH,are calculated for BxGa1-xAs and BxGa1-xSb alloys. A comparison of enthalpies indicates that BxGa1-xSb films with boron composition of 7% may be possible.

  19. The band structures of BSb and BxGa1-xSb alloys

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The band structures of BSb and BxGa1-xSb alloys are studied using first-principles calculations in the generalized gradient approximation. By SQS-8 supercells to model a random alloy, the direct transition energy-gap (Γ15v- Γ1c) bowing of 3.0 eV is obtained for BxGa1-xSb alloys in x = 0-50%, in x = 0-11% the energy-gap is the band-gap and increases by 7 meV/%B with boron composition increasing; by SQS-16 supercells the bowing parameter is about 1.9 eV in x = 0-12.5%. The formation enthalpies of mixing, ΔH, are calculated for BxGa1-xAs and BxGa1-xSb alloys. A comparison of enthalpies indicates that BxGa1-xSb films with boron composition of 7% may be possible.

  20. 75 FR 48390 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Order Approving a Proposed Rule Change...

    Science.gov (United States)

    2010-08-10

    ... FR 38571 (``Notice''). In its proposal, BX proposed to establish fees for direct 10Gb circuit... COMMISSION Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Order Approving a Proposed Rule Change...,\\2\\ a proposed rule change to establish pricing for 10Gb direct circuit connections and...

  1. 75 FR 6235 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2010-02-08

    ... Exchange Act Release No. 60886 (October 27, 2009), 74 FR 56897 (November 3, 2009) (SR-BX-2009-067). This.... 60950 (November 6, 2009), 74 FR 58666 (November 6, 2009) (SR-BX-2009-069). This proposal was effective.... AMAT Applied Materials Inc. MCO Moody's Corp. AMR AMR Corp. MET MetLife Inc. ANF Abercrombie & Fitch...

  2. 75 FR 47875 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2010-08-09

    ... Starwood Hotels & ACAS American Capital Resorts Ltd. QLD ProShares Ultra QQQ XLNX Xilinx Inc. VRSN Veri... Exchange Act Release No. 60886 (Oct. 27, 2009), 74 FR 56897 (Nov. 3, 2009) (SR-BX-2009-067). This proposal... Release No. 60950 (Nov. 6, 2009), 74 FR 58666 (Nov. 6, 2009) (SR-BX-2009-069); Securities and Exchange...

  3. 77 FR 33257 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2012-06-05

    ... COMMISSION Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness... Rules. BX Members are subject to various charges for membership, services and equipment as noted in the... either solicited or received. III. Date of Effectiveness of the Proposed Rule Change and Timing...

  4. 75 FR 54665 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of Proposed Rule Change To...

    Science.gov (United States)

    2010-09-08

    ..., Rights and Warrants. To be listed on BX, companies will need to meet the following qualitative listing...\\ The Exchange also believes that companies currently traded over-the-counter could view this market as... promote the ethical behavior of individuals associated with companies listed on BX. \\30\\ Proposed...

  5. Expression of wheat high molecular weight glutenin subunit 1Bx is affected by large insertions and deletions located in the upstream flanking sequences.

    Directory of Open Access Journals (Sweden)

    Yuke Geng

    Full Text Available To better understand the transcriptional regulation of high molecular weight glutenin subunit (HMW-GS expression, we isolated four Glu-1Bx promoters from six wheat cultivars exhibiting diverse protein expression levels. The activities of the diverse Glu-1Bx promoters were tested and compared with β-glucuronidase (GUS reporter fusions. Although all the full-length Glu-1Bx promoters showed endosperm-specific activities, the strongest GUS activity was observed with the 1Bx7OE promoter in both transient expression assays and stable transgenic rice lines. A 43 bp insertion in the 1Bx7OE promoter, which is absent in the 1Bx7 promoter, led to enhanced expression. Analysis of promoter deletion constructs confirmed that a 185 bp MITE (miniature inverted-repeat transposable element in the 1Bx14 promoter had a weak positive effect on Glu-1Bx expression, and a 54 bp deletion in the 1Bx13 promoter reduced endosperm-specific activity. To investigate the effect of the 43 bp insertion in the 1Bx7OE promoter, a functional marker was developed to screen 505 Chinese varieties and 160 European varieties, and only 1Bx7-type varieties harboring the 43 bp insertion in their promoters showed similar overexpression patterns. Hence, the 1Bx7OE promoter should be important tool in crop genetic engineering as well as in molecular assisted breeding.

  6. Binary Planets

    Science.gov (United States)

    Ryan, Keegan; Nakajima, Miki; Stevenson, David J.

    2014-11-01

    Can a bound pair of similar mass terrestrial planets exist? We are interested here in bodies with a mass ratio of ~ 3:1 or less (so Pluto/Charon or Earth/Moon do not qualify) and we do not regard the absence of any such discoveries in the Kepler data set to be significant since the tidal decay and merger of a close binary is prohibitively fast well inside of 1AU. SPH simulations of equal mass “Earths” were carried out to seek an answer to this question, assuming encounters that were only slightly more energetic than parabolic (zero energy). We were interested in whether the collision or near collision of two similar mass bodies would lead to a binary in which the two bodies remain largely intact, effectively a tidal capture hypothesis though with the tidal distortion being very large. Necessarily, the angular momentum of such an encounter will lead to bodies separated by only a few planetary radii if capture occurs. Consistent with previous work, mostly by Canup, we find that most impacts are disruptive, leading to a dominant mass body surrounded by a disk from which a secondary forms whose mass is small compared to the primary, hence not a binary planet by our adopted definition. However, larger impact parameter “kissing” collisions were found to produce binaries because the dissipation upon first encounter was sufficient to provide a bound orbit that was then rung down by tides to an end state where the planets are only a few planetary radii apart. The long computational times for these simulation make it difficult to fully map the phase space of encounters for which this outcome is likely but the indications are that the probability is not vanishingly small and since planetary encounters are a plausible part of planet formation, we expect binary planets to exist and be a non-negligible fraction of the larger orbital radius exoplanets awaiting discovery.

  7. Hanford Tank Farms Vadose Zone, Addendum to the BX Tank Farm Report

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, A.W.

    2000-07-01

    This addendum to the BX Tank Farm Report (GJO-98-40-TARA, GJO-HAN-19) published in August 1998 incorporates the results of high-rate and repeat logging activities along with shape factor analysis of the logging data. A high-rate logging system was developed and deployed in the BX Tank Farm to measure cesium-137 concentration levels in high gamma flux zones where the spectral gamma logging system was unable to collect usable data because of high dead times and detector saturation. This report presents additional data and revised visualizations of subsurface contaminant distribution in the BX Tank Farm at the DOE Hanford Site in the state of Washington.

  8. Final report for tank 241-BX-104 push mode core 126 and 127

    International Nuclear Information System (INIS)

    This is the final sample analysis report for tank 241-BX-104 (BX-104), cores 126 and 127. Two segments from each core yielded a total of 11 samples which were analyzed. The data quality objectives (DQOs) applicable to this sampling event were the Safety Screening DQO (Dukelow et al. 1995) and the Organic Safety DQO (Turner et al. 1995). The samples were received, extruded and analyzed at PNNL 325 Analytical Chemistry Laboratory (ACL). The analyses were performed in accordance with the Sample Analysis Plan (Gretsinger 1996) and indicated that the tank is safe with respect to the criteria in the Safety Screening and Organic DQO. Detailed analytical results were described in the analytical laboratory 45-day Report (Attachment 1, WHC-SD-WM-DP-171, REV. 0) and final report (Attachment 2, PNL-BX-104 REV.1) prepared by PNNL, 325 Laboratory. Corrections and/or exceptions to the PNNL final report are provided

  9. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary...

  10. Theoretical Investigation on the Geometries and Properties of Guanine-BX3 (X = F, Cl) Complex

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Geometries and binding energies were predicted at the B3LYP/6-311+G* level for the guanine-BX3 (X = F, Cl) systems and four isomers with no imaginary frequencies have been obtained for both guanine-BF3 and guanine-BCl3, respectively. Single energy calculations using much larger basis sets (6-311+G(2df,p) and aug-cc-pVDZ were carried out as well. It was found that the most stable isomer of guanine-BF3 is BF3 connected to N3 of guanine with the stabilization energy of -19.93 kcal/mol (BSSE corrected), while that of guanine-BCl3 is BCl3 connected to O10 of guanine having stabilization energy of -15.02 kcal/mol at the same level. The analyses for the combining interaction between BX3 and guanine with the atom-in-molecules theory (AIM) and natural bond orbital (NBO) methods have been performed. The results indicated that all the isomers are formed with σ-p type interactions between guanine and BX3, in which pyridine-type nitrogen or carbonyl oxygen or nitrogen atom of amino group offers its lone pair electrons to the empty p orbital of boron atom and the concomitance of charge transfer from guanine to BX3 has occurred. Still, one or two hydrogen bonds exist in some isomers of guanine-BX3 system and contribute to the stability of complex systems. Frequency analysis suggested that the stretching vibration of BX3 undergoes a red shift in complexes. Guanine-BF3 complex is more stable than guanine-BCl3 although the B-Y (Y=N, O) bond distance in the latter is shorter.

  11. Characterization of Vadose Zone Sediment: Borehole 299-E33-45 Near BX-102 in the B-BX-BY Waste Management Area

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey; Last, George V.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Lindenmeier, Clark W.; Lindberg, Michael J.; Clayton, Ray E.; Legore, Virginia L.; Orr, Robert D.; Kutnyakov, Igor V.; Baum, Steven R.; Geiszler, Keith N.; Brown, Christopher F.; Valenta, Michelle M.; Vickerman, Tanya S.

    2008-09-11

    This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.22. The data was removed due to potential contamination introduced during the acid extraction process. The remaining text is unchanged from the original report issued in 2002. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area B-BX-BY. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole 299-E33-45 installed northeast of tank BX-102.

  12. Two-dimensional BX (X = P, As, Sb) semiconductors with mobilities approaching graphene.

    Science.gov (United States)

    Xie, Meiqiu; Zhang, Shengli; Cai, Bo; Zhu, Zhen; Zou, Yousheng; Zeng, Haibo

    2016-07-21

    Carrier mobility plays a key role in the performance of microelectronic devices, especially the field effect transistors (FET). To design next generation two-dimensional (2D) FET, stable channel materials with a higher carrier mobility than silicon and a significant band gap are highly desirable, but are still not discovered. Here, we report a group of 2D materials of BX (X = P, As, and Sb), which are semiconducting with an ultrahigh carrier mobility. Using first-principles calculations, we find that all BX configurations are similar to graphene, but possess direct bandgaps of 1.36, 1.14, and 0.49 eV, respectively. Based on deformation potential theory, BX monolayers are predicted to have superior mobilities (>10(4) cm(2) V(-1) s(-1)) to phosphorene. In particular, the electron mobility of monolayer BSb is 3.2 × 10(5) cm(2) V(-1) s(-1), approaching the figure of merit in graphene (∼3 × 10(5) cm(2) V(-1) s(-1)). These results demonstrate that BX monolayers are of paramount significance for next-generation 2D FET manufacture. PMID:27346538

  13. X-ray crystal structure of divalent metal-activated ß-xyloisdase, RS223BX

    Science.gov (United States)

    We report the first X-ray structure of a glycoside hydrolase family 43 ß-xylosidase, RS223BX, which is strongly activated by the addition of divalent metal cations. The 2.69 Å structure reveals that the Ca2+ cation is located at the back of the active site pocket. The Ca2+ coordinates to H274 to sta...

  14. Supporting document for the historical tank content estimate for BX-tank farm

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.

    1996-06-28

    This Supporting Document provides historical in-depth characterization information on BX-Tank Farm, such as historical waste transfer and level data, tank physical information,temperature plots, liquid observation well plots, chemical analyte and radionuclide inventories for the Historical Tank Content Estimate Report for the northeast quadrant of the Hanford 200 East Area.

  15. Supporting document for the historical tank content estimate for BX-tank farm

    International Nuclear Information System (INIS)

    This Supporting Document provides historical in-depth characterization information on BX-Tank Farm, such as historical waste transfer and level data, tank physical information,temperature plots, liquid observation well plots, chemical analyte and radionuclide inventories for the Historical Tank Content Estimate Report for the northeast quadrant of the Hanford 200 East Area

  16. Design on Improved Assistant Cluster Head Algorithm Based on PEGASIS%基于PEGASIS的助理簇头改进算法设计

    Institute of Scientific and Technical Information of China (English)

    戴花; 王建平

    2011-01-01

    Based on the study of LEACH and PEGASIS algorithm,the thesis proposed an improved algorithm Assistant cluster head ASCH.The algorithm can in wireless sensor networks,cluster head node according to geographical location,residual energy and the number of cl%基于对LEACH算法和PEGASIS算法的研究,提出助理簇头改进ASCH算法。该算法能够在无线传感器网络中,根据簇头节点所处的地理位置、剩余能量及簇内成员节点数目,动态决定是否需要在簇内产生助理簇头,并在需要产生助理簇头的簇内选择合适的节点来减少簇头通信的能耗。在PEGASIS中加入助理簇头后,改进后的助理簇头改进算法的性能指标与已有算法相比均有提高,在均衡及节能、延长网络生命周期方面起到了积极的作用。

  17. 78 FR 4482 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of Amendment No. 1, and...

    Science.gov (United States)

    2013-01-22

    ... amend two sections of its rules \\17\\ concerning corporate governance requirements for companies listed..., ``Exemptions from Certain Corporate Governance Requirements.'' In addition, BX proposes to make some other... compensation decisions in today's corporate governance environment.'' The Exchange concluded that ``there...

  18. Tank characterization report for Single-Shell Tank 241-BX-107

    Energy Technology Data Exchange (ETDEWEB)

    Raphael, G.F.

    1994-09-01

    This study examined and assessed the status, safety issues, composition, and distribution of the wastes contained in the tank 241-BX-107. Historical and most recent information, ranging from engineering structural assessment experiments, process history, monitoring and remediation activities, to analytical core sample data, were compiled and interpreted in an effort to develop a realistic, contemporary profile for the tank BX-107 contents. The results of this is study revealed that tank BX-107, a 2,006,050 L (530,000 gal) cylindrical single-shell, dished-bottom carbon-steel tank in the 200 East Area of the Hanford Site, was classified as sound. It has been interim stabilized and thus contains less than 189,250 L (50,000 gal) of interstitial liquid, and less than 18,925 L (5,000 gal) of supernatant. It has also been partially interim isolated, whereby all inlets to the tank are sealed to prevent inadvertent addition of liquid. At a residual waste level of {approximately}3.07 m (120.7 {+-} 2 in. from sidewall bottom or {approximately}132.9 in. from center bottom), it is estimated that the tank BX-107 contents are equivalent to 1,305,825 L (345,000 gal). The vapor space pressure is at atmospheric. The latest temperature readings, which were taken in July 1994, show a moderate temperature value of 19{degrees}C (66{degrees}F). Two supernatant samples were collected in 1974 and 1990, prior to interim stabilization. Sludge core samples were obtained in 1979 and 1992.

  19. Subsurface Conditions Description of the B and BX and BY Waste Management Area

    Energy Technology Data Exchange (ETDEWEB)

    WOOD, M.I.

    2000-03-13

    This document provides a discussion of the subsurface conditions relevant to the occurrence and migration of contaminants in the vadose zone and groundwater underlying the 241-B, -BX, and -BY tank farms. This document provides a concise summary of existing information in support of characterization planning. This document includes a description of the available environmental contamination data and a limited, qualitative interpretation of these data.

  20. First-principles investigation of BAs and BxGa1-xAs alloys

    Institute of Scientific and Technical Information of China (English)

    Xiong De-Ping; Zhou Shou-Li; Wang Qi; Ren Xiao-Min

    2008-01-01

    Using first-principles calculations in the generalized gradient approximation, the electronic properties of BAs and BxGa1-xAs alloys are studied. At the Brillouin-zone centre, the lowest conduction band is the three-degenerate p-like Γ15c state rather than s-like Γ1c state, and the conduction band minimum (CBM) is along the △ line between the Γ and X points-at approximately 11/14(1,0,0)2π/a. With boron content at 0%-18.75%, BxGa1-xAs alloys have a small (2.6 eV) and relatively composition-independent band-gap bowing parameter, the band-gap increases monotonically by ~18meV/B% with increasing boron content. In addition, the formation enthalpies of mixing for BxGa1-xAs alloys with boron content at 6.25% and 12.5% are calculated, and the large formation enthalpies may explain the difficulty in alloying boron to GaAs.

  1. Electrical and thermal transport properties of Y bxCo4Sb12 filled skutterudites with ultrahigh carrier concentrations

    Directory of Open Access Journals (Sweden)

    Yulong Li

    2015-11-01

    Full Text Available For filled skutterudites, element Yb is one of the most common and important fillers. However, the optimal carrier concentration range in Y bxCo4Sb12 filled skutterudites has not been determined as a result of the low Yb filling fraction limit. In this study, a non-equilibrium fabrication process (MS-SPS process, consisting of a melt-spinning method and a spark plasma sintering technique, has been applied to prepare Y bxCo4Sb12 samples. The Yb filling fraction is successfully extended to 0.35, which provides the possibility to clarify the optimal carrier concentration range for Yb-filled skutterudites. High carrier concentrations, with a maximum of around 1 × 1021 cm−3, were achieved in the MS-SPS Y bxCo4Sb12 samples due to the significantly enhanced Yb filling fractions. The phase compositions, lattice parameters, electrical and thermal transport properties of the MS-SPS Y bxCo4Sb12 samples with high carrier concentrations were systematically investigated. An optimal carrier concentration range of around 5 ∼ 6 × 1020 cm−3, corresponding to the actual Yb filling fraction of around 0.21∼0.26, has been determined, which displays the highest thermoelectric performance in Y bxCo4Sb12 thermoelectric materials.

  2. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  3. Heme oxygenase-1 regulates the progression of K/BxN serum transfer arthritis.

    Directory of Open Access Journals (Sweden)

    Rita Brines

    Full Text Available BACKGROUND: Heme oxygenase-1 (HO-1 is induced in many cell types as a defense mechanism against stress. We have investigated the possible role of endogenous HO-1 in the effector phase of arthritis using the K/BxN serum transfer model of arthritis in HO-1 heterozygous and homozygous knock-out mice. METHODOLOGY/PRINCIPAL FINDINGS: Arthritis was induced in C57/Black-6 xFVB (HO-1(+/+, HO-1(+/- and HO-1(-/- mice by intraperitoneal injection of 150 µl serum from arthritic K/BxN mice at days 0 and 2. Blood was collected and animals were sacrificed at day 10. Histological analysis was performed in ankle sections. The levels of inflammatory mediators were measured in serum and paw homogenates by enzyme-linked immunosorbent assay or Multiplex technology. The incidence of arthritis was higher in HO-1(+/- and HO-1(-/- groups compared with HO-1(+/+. The inflammatory response was aggravated in HO-1(+/- mice as shown by arthritic score and the migration of inflammatory cells that could be related to the enhancement of CXCL-1 production. In addition, the HO-1(+/- group showed proteoglycan depletion significantly higher than HO-1(+/+ mice. Serum levels of matrix metalloproteinase-3, monocyte chemotactic protein-1, plasminogen activator inhibitor-1, E-selectin and intercellular adhesion molecule-1 were increased in arthritic HO-1(-/- mice, whereas vascular endothelial growth factor and some cytokines such as interferon-γ showed a reduction compared to HO-1(+/+ or HO-1(+/- mice. In addition, down-regulated gene expression of ferritin, glutathione S-reductase A1 and superoxide dismutase-2 was observed in the livers of arthritic HO-1(+/- animals. CONCLUSION/SIGNIFICANCE: Endogenous HO-1 regulates the production of systemic and local inflammatory mediators and plays a protective role in K/BxN serum transfer arthritis.

  4. The Sightline to Q2343-BX415: Clues to Galaxy Formation in a Quasar Environment

    Science.gov (United States)

    Rix, Samantha A.; Pettini, Max; Steidel, Charles C.; Reddy, Naveen A.; Adelberger, Kurt L.; Erb, Dawn K.; Shapley, Alice E.

    2007-11-01

    We have discovered a strong DLA coincident in redshift with the faint QSO Q2343-BX415 (R=20.2, zem=2.57393). Follow-up observations at intermediate spectral resolution reveal that the metal lines associated with this proximate DLA (PDLA) consist of two sets of absorption components. One set is moving toward the quasar with velocities of ~150-600 km s-1 this gas is highly ionized and does not fully cover the continuum source, suggesting that it is physically close to the active nucleus. The other, which accounts for most of the neutral gas, is blueshifted relative to the QSO, with the strongest component at ~-160 km s-1. We consider the possibility that the PDLA arises in the outflowing interstellar medium of the host galaxy of Q2343-BX415, an interpretation supported by strong C IV and N V absorption at nearby velocities, and by the intense radiation field longward of the Lyman limit implied by the high C II*/H I ratio. If Q2343-BX415 is the main source of these UV photons, then the PDLA is located at either ~8 or ~37 kpc from the active nucleus. Alternatively, the absorber may be a foreground star-forming galaxy unrelated to the quasar and coincidentally at the same redshift, but our deep imaging and follow-up spectroscopy of the field of Q2343-BX415 has not yet produced a likely candidate. We measure the abundances of 14 elements in the PDLA, finding an overall metallicity of ~1/5 solar and a normal pattern of relative element abundances for this metallicity. Thus, in this PDLA there is no evidence for the supersolar metallicities that have been claimed for some proximate, high-ionization, systems. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

  5. Binary mask programmable hologram.

    Science.gov (United States)

    Tsang, P W M; Poon, T-C; Zhou, Changhe; Cheung, K W K

    2012-11-19

    We report, for the first time, the concept and generation of a novel Fresnel hologram called the digital binary mask programmable hologram (BMPH). A BMPH is comprised of a static, high resolution binary grating that is overlaid with a lower resolution binary mask. The reconstructed image of the BMPH can be programmed to approximate a target image (including both intensity and depth information) by configuring the pattern of the binary mask with a simple genetic algorithm (SGA). As the low resolution binary mask can be realized with less stringent display technology, our method enables the development of simple and economical holographic video display.

  6. Intracellular Distributing and Interferon-γ Secretion of Human Interleukin-18 in BxPC-3 Cells

    OpenAIRE

    Yang, Jin; Chen, Linlin; Xu, Bin; Xu, Jian; Sun, Jinquan; Shen, Wen; Zhang, Ting

    2014-01-01

    Objective: To investigate the characteristics of interleukin-18 (IL-18) in vitro, explore IL-18, interferon-γ (IFN-γ) and interleukin-2 (IL-2) secretive activity in BxPC-3 line cells with interleukin-18 mutants. Methods: Human IL-18 full-length gene (hIL-18-F) and the hIL-18 presumed mature protein gene (hIL-18-M) were inserted into the expression vector pEGFP-N1, to construct recombinant plasmids as Mu0, Mu1, Mu2, Mu3, and Mu4, and the recombinant plasmids were then transferred into BxPC-3 l...

  7. PHOEBE: PHysics Of Eclipsing BinariEs

    Science.gov (United States)

    Prsa, Andrej; Matijevic, Gal; Latkovic, Olivera; Vilardell, Francesc; Wils, Patrick

    2011-06-01

    PHOEBE (PHysics Of Eclipsing BinariEs) is a modeling package for eclipsing binary stars, built on top of the widely used WD program (Wilson & Devinney 1971). This introductory paper overviews most important scientific extensions (incorporating observational spectra of eclipsing binaries into the solution-seeking process, extracting individual temperatures from observed color indices, main-sequence constraining and proper treatment of the reddening), numerical innovations (suggested improvements to WD's Differential Corrections method, the new Nelder & Mead's downhill Simplex method) and technical aspects (back-end scripter structure, graphical user interface). While PHOEBE retains 100% WD compatibility, its add-ons are a powerful way to enhance WD by encompassing even more physics and solution reliability.

  8. Thermodynamical and electronic properties of Bx Al1-x N alloys: A first principle study

    Science.gov (United States)

    Kumar, S.; Joshi, Suman; Joshi, B.; Auluck, S.

    2015-11-01

    A series of first principle calculations were carried out to investigate thermodynamical, electronic and optical properties of cubic Bx Al1-x N ordered alloys using supercell approach within density functional theory (DFT). Here we calculate the lattice constants using van der Waals density functional (vdW-DF) at several concentrations (x) of boron. We find that the vdW-DF prediction shows slightly better agreement with experiment in contrast to local density approximation (LDA)/generalized gradient approximation (GGA). The results show that the direct energy band gap (Γv-Γc) has strong nonlinear dependence on the concentration (x). At x=0.04 and 0.84, Bx Al1-x N has a phase transition from direct to an indirect band gap semiconductor. To describe the alloys' solubility, formation enthalpy were calculated and fitted to quadratic function to obtain interaction parameter. The calculated T-x phase diagram shows a broad miscibility gap with a high critical temperature equal to 3063 K. The calculated dielectric function is explained in terms of band structure and density of states and compared with the available experimental data, showing good agreement.

  9. Formation, stability and crystal structure of mullite-type Al6-xBxO9

    Science.gov (United States)

    Hoffmann, K.; Hooper, T. J. N.; Murshed, M. M.; Dolotko, O.; Révay, Z.; Senyshyn, A.; Schneider, H.; Hanna, J. V.; Gesing, Th. M.; Fischer, R. X.

    2016-11-01

    Mullite-type Al6-xBxO9 compounds were studied by means of powder diffraction and spectroscopic methods. The backbones of this structure are chains of edge-connected AlO6 octahedra crosslinked by AlO- and BO-polyhedra. Rietveld refinements show that the a and b lattice parameters can be well resolved, thus representing an orthorhombic metric. A continuous decrease of the lattice parameters most pronounced in c-direction indicates a solid solution for Al6-xBxO9 with 1.09≤x≤2. A preference of boron in 3-fold coordination is confirmed by 11B MAS NMR spectroscopy and Fourier calculations based on neutron diffraction data collected at 4 K. Distance Least Squares modeling was performed to simulate a local geometry avoiding long B-O distances linking two octahedral chains by planar BO3 groups yielding split positions for the oxygen atoms and a strong distortion in the octahedral chains. The lattice thermal expansion was calculated using the Grüneisen first-order equation of state Debye-Einstein-Anharmonicity model.

  10. Tank characterization report for single-shell tank 241-BX-110

    Energy Technology Data Exchange (ETDEWEB)

    RASMUSSEN, J.H.

    1999-02-23

    A major function of the Tank Waste Remediation System (TWRS) is to characterize waste in support of waste management and disposal activities at the Hanford Site. Analytical data from sampling and analysis and other available information about a tank are compiled and maintained in a tank characterization report (TCR). This report and its appendices serve as the TCR for single-shell tank 241-BX-110. The objectives of this report are (1) to use characterization data in response to technical issues associated with tank 241-BX-110 waste, and (2) to provide a standard characterization of the waste in terms of a best-basis inventory estimate. Section 2.0 summarizes the response to technical issues, Section 3.0 shows the best-basis inventory estimate, and Section 4.0 makes recommendations about the tank's safety status and additional sampling needs. The appendices contain supporting data and information. This report supports the requirements of the Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1997), Milestone M-44-15b, change request M-44-97-03 to ''issue characterization deliverables consistent with the Waste Information Requirements Document developed for 1998.''

  11. Tank characterization report for single-shell tank 241-BX-110

    International Nuclear Information System (INIS)

    A major function of the Tank Waste Remediation System (TWRS) is to characterize waste in support of waste management and disposal activities at the Hanford Site. Analytical data from sampling and analysis and other available information about a tank are compiled and maintained in a tank characterization report (TCR). This report and its appendices serve as the TCR for single-shell tank 241-BX-110. The objectives of this report are (1) to use characterization data in response to technical issues associated with tank 241-BX-110 waste, and (2) to provide a standard characterization of the waste in terms of a best-basis inventory estimate. Section 2.0 summarizes the response to technical issues, Section 3.0 shows the best-basis inventory estimate, and Section 4.0 makes recommendations about the tank's safety status and additional sampling needs. The appendices contain supporting data and information. This report supports the requirements of the Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1997), Milestone M-44-15b, change request M-44-97-03 to ''issue characterization deliverables consistent with the Waste Information Requirements Document developed for 1998.''

  12. Rhodococcus sp.BX2菌对乙腈的降解特性及降解途径研究%Characteristics and pathway of acetonitrile degradation by Rhodococcus sp.BX2

    Institute of Scientific and Technical Information of China (English)

    孙晶; 熊明华; 成小松; 李悦; 臧海莲; 李春艳

    2012-01-01

    对Rhodococcus sp.BX2菌降解乙腈的特性及其降解途径进行了研究.结果显示,在底物浓度为800mg·L-1,接种量为1.0%,培养温度为35℃,环境pH为7.5的条件下,16h时Rhodococcus sp.BX2菌对乙腈的降解率为95.98%;添加葡萄糖可在培养初期加快Rhodococcus sp.BX2菌的生长和对乙腈的降解,蔗糖、乙酰胺和尿素对其影响不大.将BX2菌接种到含有高乙腈浓度(25000mg·L-1)的合成废水中,培养180h后,乙腈降解率可达88.59%.在催化反应60min后,Rhodococcus sp.BX2腈水合酶与腈水解酶的总酶活可达到422.81U·mL-1,对其相关基因序列的分析结果表明,Rhodococcus sp.BX2中同时存在腈水解酶基因和腈水合酶基因,因此,确定乙腈的降解主要由腈水合酶途径完成,可能同时存在腈水解酶的降解途径.%The characteristics and pathway of acetonitrile degradation by Rhodococcus sp.BX2 were investigated in this study. Results showed that with the initial acetonitrile concentration of 800 mg · L-1, the degradation rate was 95.98% in 16 hours under the condition of inoculum 1.0%, 35 ℃ and pH value 7.5.Glucose could accelerate the degradation of acetonitrile in the initial period, while sucrose, acetamide and urea had slight impact. The degradation rate could reach 88.59% when BX2 was cultured in the synthetic wastewater with high concentration of acetonitrile (25000 mg · L-1) for 180 hours. Total enzyme activities was 422.81 U · mL-1 when incubated for 60 minutes. The results of related genes sequence showed that Rhodococcus sp BX2 had both nitrile hydrolase gene and nitrile hydratase gene. The degradation pathway of acetonitrile by Rhodococcus sp. BX2 was mainly nitrile hydratase (NHase), with possible pathway of the nitrile hydrolase.

  13. 78 FR 55318 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-09-10

    ..., 2011), 76 FR 49807 (August 11, 2011) (SR-BX-2011-051). At this time, the new continuing education... system for the registration of associated persons of Exchange members that are not also FINRA members: (1... on the content outline for the Series 56 exam, which covers the main categories of rules...

  14. 78 FR 76353 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-12-17

    ... costs associated with operating NOS, membership fees at away markets, Options Regulatory Fees (``ORFs... and technical costs associated with operating NOS, membership fees at away markets, ORFs and technical..., 2013), 78 FR 51242 (August 20, 2013) (SR-Topaz-2013-01). 2. Statutory Basis BX believes that...

  15. 78 FR 3053 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-01-15

    ... routing fee in addition to the away market's transaction fee. \\3\\ In addition to membership fees and... associated with operating the order router, membership fees at away markets, and technical costs associated... 26, 2012) 77 FR 39277 (July 2, 2012) (SR-BX-2012-030). The Exchange also believes that the...

  16. 77 FR 43883 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2012-07-26

    ... addition to membership fees and transaction fees, the Exchange also incurs an Options Regulatory Fee when... the order router, membership fees at away markets, and technical costs associated with routing.\\5\\ For... FR 405688 (July 10, 2012) (SR-BX-2012-043). Firm/market Exchange Customer maker/broker-...

  17. 78 FR 9752 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-02-11

    ... to create the Levels' trigger points. The values then remain in effect until the next quarterly... Exchange Act Release No. 67090 (May 31, 2012), 77 FR 33531 (June 6, 2012) (SR-BX-2011-068). \\6\\ The rule... Exchange Act Release No. 39846 (April 9, 1998), 63 FR 18477 (April 15, 1998) (SR-NYSE-98-06,...

  18. 76 FR 72231 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2011-11-22

    ... Discretionary Orders, by definition, have a non-displayed discretionary price range. BX believes that... designated as a Pegged Order, an Intermarket Sweep Order, a Price to Comply order, or a Price to Comply Post... are orders that have a displayed price and size, as well as a non-displayed discretionary price...

  19. 78 FR 48748 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-08-09

    ... ``dividend, payment or distribution'' and including stock splits as an example of corporate actions covered... splits.\\11\\ In addition, BX is adding language to the rule to include symbol changes and changes in the... market hours. \\6\\ Securities Exchange Act Release No. 69456 (April 25, 2013), 78 FR 25510 (May 1,...

  20. 75 FR 4129 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of Proposed Rule Change To...

    Science.gov (United States)

    2010-01-26

    ... Organization's Statement of the Purpose of, and Statutory Basis for, the Proposed Rule Change In its filing...-Regulatory Organization's Statement of the Purpose of, and Statutory Basis for, the Proposed Rule Change 1... 27, 2009), 74 FR 106 (June 4, 2009) (SR-FINRA-2009-016). BX is adopting the new FINRA rule in...

  1. 75 FR 4438 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of Proposed Rule Change To...

    Science.gov (United States)

    2010-01-27

    ...-Regulatory Organization's Statement of the Purpose of, and Statutory Basis for, the Proposed Rule Change In...), 74 FR 1069 (June 4, 2009) (SR-FINRA-2009-016). BX is adopting the new FINRA rule in full and is re... amended. C. Self-Regulatory Organization's Statement on Comments on the Proposed Rule Change Received...

  2. 78 FR 16746 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-03-18

    ... 4613. \\6\\ See Securities Exchange Act Release No. 67091 (May 31, 2012), 77 FR 33498 (June 6, 2012.... 67090 (May 31, 2012), 77 FR 33531 (June 6, 2012) (SR-BATS-2011-038; SR-BYX-2011- 025; SR-BX-2011-068; SR... response to the Regulation NMS Plan to Address Extraordinary Market Volatility, and paragraph (e) to...

  3. 76 FR 55445 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2011-09-07

    ... Modify Its Contents August 30, 2011. Pursuant to Section 19(b)(1) of the Securities Exchange Act of 1934... BBO Feed to the BX MatchView Feed (the ``Feed'') and to modify the contents of the Feed in two ways... transparency through the dissemination of the most accurate quotations data and by clarifying its contents....

  4. 78 FR 17952 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-03-25

    ... options so that inconsistent position limits do not produce competitive advantages and disadvantages among.... Self-Regulatory Organization's Statement on Comments on the Proposed Rule Change Received From Members... COMMISSION Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate...

  5. 76 FR 63969 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2011-10-14

    ... advantage. \\11\\ 15 U.S.C. 78f. \\12\\ 15 U.S.C. 78f(b)(5). B. Self-Regulatory Organization's Statement on... Organization's Statement on Comments on the Proposed Rule Change Received From Members, Participants, or Others... COMMISSION Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate...

  6. 77 FR 30576 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of Proposed Rule Change With...

    Science.gov (United States)

    2012-05-23

    .... 64090 (March 17, 2011), 76 FR 16462 (March 23, 2011) (SR-BX-2011-007); 65514 (October 7, 2011), 76 FR... receiving responses to immediate or cancel (``IOC'') orders that it sent to the routing destination, and... systems issue does not exist), NES should receive an immediate response to an IOC order from a...

  7. Supporting document for the North East Quandrant Historical Tank Content Estimate Report for BX-Tank Farm

    International Nuclear Information System (INIS)

    This supporting document provides historical in-depth characterization information gathered on BX-Tank Farm, such as historical waste transfer and level data, tank physical information, temperature data, sampling data, and drywell and liquid observation well data for Historical Tank Content Estimate Report of the NE Quandrant and the Hanford 200 East Areas

  8. Supporting document for the North East Quandrant Historical Tank Content Estimate Report for BX-Tank Farm

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.

    1994-06-01

    This supporting document provides historical in-depth characterization information gathered on BX-Tank Farm, such as historical waste transfer and level data, tank physical information, temperature data, sampling data, and drywell and liquid observation well data for Historical Tank Content Estimate Report of the NE Quandrant and the Hanford 200 East Areas.

  9. 78 FR 38757 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Science.gov (United States)

    2013-06-27

    ... consistent with past Commission precedent and economic theory.\\8\\ \\7\\ See BX Rule 7023. \\8\\ In economic terms, charging lower fees to non-professional consumers increases overall economic welfare by increasing output... various constituencies (i.e., lower prices are charged to consumers with more elastic demand) and...

  10. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  11. Computation of eigenpairs of Ax = lambda Bx for vibrations of spinning deformable bodies

    Science.gov (United States)

    Utku, S.; Clemente, J. L. M.

    1984-01-01

    It is shown that, when linear theory is used, the general eigenvalue problem related with the free vibrations of spinning deformable bodies is of the type AX = lambda Bx, where A is Hermitian, and B is real positive definite. Since the order n of the matrices may be large, and A and B are banded or block banded, due to the economics of the numerical solution, one is interested in obtaining only those eigenvalues which fall within the frequency band of interest of the problem. The paper extends the well known method of bisections and iteration of R to the n power to n dimensional complex spaces, i.e., to C to the n power, so that it can be applied to the present problem.

  12. Expression profiling of wild type and β-catenin gene disrupted human BxPC-3 pancreatic adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Petter Angell Olsen

    2015-06-01

    Full Text Available To study the role of WNT/β-catenin signaling in pancreatic adenocarcinoma, human BxPC-3 cell lines deficient of the central canonical WNT signaling protein β-catenin were established by using zinc-finger nuclease mediated targeted genomic disruption of the β-catenin gene (CTNNB1. Comparison of the global transcription levels in wild type cells with two β-catenin gene disrupted clones identified 85 transcripts that were the most differentially regulated. Gene ontology (GO term enrichment analysis of these transcripts identified “cell adhesion” as the most significantly enriched GO term. Here we describe the data from the transcription profiling analysis published in the article “Implications of Targeted Genomic Disruption of β-Catenin in BxPC-3 Pancreatic Adenocarcinoma Cells” [1]. Data have been deposited to the Gene Expression Omnibus (GEO database repository with the dataset identifier GSE63072.

  13. BX in-situ oil-shale project. Quarterly technical progress report, June 1, 1981-August 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Dougan, P.M.

    1981-09-20

    June 1, 1981-August 31, 1981 was the third consecutive quarter of superheated steam injection at the BX In Situ Oil Shale Project. Injection was continuous except for the period of July 14th to August 1st when the injection was suspended during the drilling of core hole BX-37. During the quarter, 99,760 barrels of water as superheated steam were injected into Project injection wells at an average well head temperature of 752/sup 0/F and an average wellhead pressure of 1312 PSIG. During the same period, 135,469 barrels of fluid were produced from the Project production wells for a produced to injected fluid ratio of 1.36 to 1.0. Net oil production during the quarter was 38 barrels.

  14. Binaries in globular clusters

    Science.gov (United States)

    Hut, Piet; Mcmillan, Steve; Goodman, Jeremy; Mateo, Mario; Phinney, E. S.; Pryor, Carlton; Richer, Harvey B.; Verbunt, Frank; Weinberg, Martin

    1992-01-01

    Recent observations have shown that globular clusters contain a substantial number of binaries most of which are believed to be primordial. We discuss different successful optical search techniques, based on radial-velocity variables, photometric variables, and the positions of stars in the color-magnitude diagram. In addition, we review searches in other wavelengths, which have turned up low-mass X-ray binaries and more recently a variety of radio pulsars. On the theoretical side, we give an overview of the different physical mechanisms through which individual binaries evolve. We discuss the various simulation techniques which recently have been employed to study the effects of a primordial binary population, and the fascinating interplay between stellar evolution and stellar dynamics which drives globular-cluster evolution.

  15. The binary proletariat

    OpenAIRE

    Bolt, Nate

    2000-01-01

    In the endless quest to transform itself, capitalism has spawned a new working class. The proletariat was an essential product of the industrial revolution, and the lighter, more efficient capitalism of the digital revolution has created the Binary Proletariat.

  16. Eclipsing Binary Pulsars

    CERN Document Server

    Freire, P C C

    2004-01-01

    The first eclipsing binary pulsar, PSR B1957+20, was discovered in 1987. Since then, 13 other eclipsing low-mass binary pulsars have been found, 12 of these are in globular clusters. In this paper we list the known eclipsing binary pulsars and their properties, with special attention to the eclipsing systems in 47 Tuc. We find that there are two fundamentally different groups of eclipsing binary pulsars; separated by their companion masses. The less massive systems (M_c ~ 0.02 M_sun) are a product of predictable stellar evolution in binary pulsars. The systems with more massive companions (M_c ~ 0.2 M_sun) were formed by exchange encounters in globular clusters, and for that reason are exclusive to those environments. This class of systems can be used to learn about the neutron star recycling fraction in the globular clusters actively forming pulsars. We suggest that most of these binary systems are undetectable at radio wavelengths.

  17. Stellar collisions during binary-binary and binary-single star interactions

    NARCIS (Netherlands)

    J.M. Fregeau; P. Cheung; S.F. Portegies Zwart; F.A. Rasio

    2004-01-01

    Physical collisions between stars occur frequently in dense star clusters, either via close encounters between two single stars, or during strong dynamical interactions involving binary stars. Here we study stellar collisions that occur during binary-single and binary-binary interactions, by perform

  18. Isolation and Molecular Characterization of High Molecular Weight Glutenin Subunit Genes 1Bx13 and 1By16 from Hexaploid Wheat

    Institute of Scientific and Technical Information of China (English)

    Bin-Shuang Pang; Xue-Yong Zhang

    2008-01-01

    The high molecular weight glutenin subunit (HMW-GS) pair 1Bx13+1Byt6 are recognized to positively correlate with bread-making quality; however, their molecular data remain unknown. In order to reveal the mechanism by which 1By16 and 1Bx13 creates high quality, their open reading frames (ORFs) were amplified from common wheat Atlas66 and Jimai 20 using primers that were designed based on published sequences of HMW glutenin genes. The ORF of 1By16 was 2220bp, deduced into 738 amino acid residues with seven cysteines including 59 hexapeptides and 22 nanopeptides motifs. The ORF of 1Bx13 was 2385bp, deduced into 795 amino acid residues with four cysteines including 68 hexapeptides, 25 nanopeptides and six tripeptides motifs. We found that 1By16 was the largest y-type HMW glutenin gene described to date in common wheat. The 1By16 had 36 amino acid residues inserted in the central repetitive domain compared with 1By15. Expression in bacteria and western-blot tests confirmed that the sequence cloned was the ORF of HMW-GS 1By16, and that 1Bx13 was one of the largest 1Bx genes that have been described so far in common wheat, exhibiting a hexapeptide (PGQGQQ) insertion in the end of central repetitive domain compared with 1Bx7. A phylogenetic tree based on the deduced full-length amino acid sequence alignment of the published HMW-GS genes showed that the 1By16 was clustered with Glu-IB-2, and that the 1Bx13 was clustered with Glu-1B-1 alleles.

  19. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  20. Binary Masking & Speech Intelligibility

    DEFF Research Database (Denmark)

    Boldt, Jesper

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experime...... mask using a directional system and a method for correcting errors in the target binary mask. The last part of the thesis, proposes a new method for objective evaluation of speech intelligibility.......The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either...... experiments under ideal conditions or as experiments under more realistic conditions useful for real-life applications such as hearing aids. In the experiments under ideal conditions, the previously defined ideal binary mask is evaluated using hearing impaired listeners, and a novel binary mask -- the target...

  1. Binary Neutron Star Mergers

    Directory of Open Access Journals (Sweden)

    Joshua A. Faber

    2012-07-01

    Full Text Available We review the current status of studies of the coalescence of binary neutron star systems. We begin with a discussion of the formation channels of merging binaries and we discuss the most recent theoretical predictions for merger rates. Next, we turn to the quasi-equilibrium formalisms that are used to study binaries prior to the merger phase and to generate initial data for fully dynamical simulations. The quasi-equilibrium approximation has played a key role in developing our understanding of the physics of binary coalescence and, in particular, of the orbital instability processes that can drive binaries to merger at the end of their lifetimes. We then turn to the numerical techniques used in dynamical simulations, including relativistic formalisms, (magneto-hydrodynamics, gravitational-wave extraction techniques, and nuclear microphysics treatments. This is followed by a summary of the simulations performed across the field to date, including the most recent results from both fully relativistic and microphysically detailed simulations. Finally, we discuss the likely directions for the field as we transition from the first to the second generation of gravitational-wave interferometers and while supercomputers reach the petascale frontier.

  2. Aromaticity of Heterofullerenes C18BxNy (x+y=2) and Their Molecular Ions

    Institute of Scientific and Technical Information of China (English)

    Jia-li Chen; Ablikim Kerim

    2008-01-01

    The axomaticity of all possible substituted fullerene isomers of C18N2,C18N2,C18BN,and their molecular ions which originate from the C20 (Ih) cage were studied by the topological resonance energy (TRE) and the percentage topological resonance energy methods.The relationship between the aromaticity of C18BxNy isomers and the sites where the heteroatoms dope at the C20 (Ih) cage is discussed.Calculation results show that at the neutral and cationic states all the isomers axe predicted to be antiaromatic with negative TREs,but their polyvalent anions are predicted to be aromatic with positive TREs.The most stable isomer is formed by heteroatom doping at the 1,11-sites in C18N2,C18B2,and C18BN.Heterofullerenes are more aromatic than C20.The stability order in the neutral states is C18N2>C18BN>C18B2>C20.The stability order in closed-shell is C18B28->C206->C18BN6->C18N24-.This predicts theoretically that their polyvalent anions have high aromaticity.

  3. Extremely Energetic 4B/X17.2 Flare and Associated Phenomena

    Indian Academy of Sciences (India)

    Wahab Uddin; Ramesh Chandra; Syed Salman Ali

    2006-06-01

    We observed 4B/X17.2 flare in H from super-active region NOAA 10486 at ARIES, Nainital. This is one of the largest flares of current solar cycle 23, which occurred near the Sun’s center and produced extremely energetic emission almost at allwavelengths from -ray to radio-waves. The flare is associated with a bright/fast full-halo earth directed CME, strong type II, type III and type IV radio bursts, an intense proton event and GLE. This flare is well observed by SOHO, RHESSI and TRACE. Our H observations show the stretching/de-twisting and eruption of helically twisted S shaped (sigmoid) filament in the south–west direction of the active region with bright shock front followed by rapid increase in intensity and area of the gigantic flare. The flare shows almost similar evolution in H, EUV and UV. We measure the speed of H ribbon separation and the mean value is ∼ 70 km s-1. This is used together with photospheric magnetic field to infer a magnetic reconnection rate at three HXR sources at the flare maximum. In this paper, we also discuss the energetics of active region filament, flare and associated CME.

  4. Binary Popldation Synthcsis Study

    Institute of Scientific and Technical Information of China (English)

    HAN Zhanwen

    2011-01-01

    Binary population synthesis (BPS), an approach to evolving millions of stars (including binaries) simultaneously, plays a crucial role in our understanding of stellar physics, the structure and evolution of galaxies, and cosmology. We proposed and developed a BPS approach, and used it to investigate the formation of many peculiar stars such as hot subdwarf stars, progenitors of type la supernovae, barium stars, CH stars, planetary nebulae, double white dwarfs, blue stragglers, contact binaries, etc. We also established an evolution population synthesis (EPS) model, the Yunnan Model, which takes into account binary interactions for the first time. We applied our model for the origin of hot subdwarf stars in the study of elliptical galaxies and explained their far-UV radiation.

  5. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  6. Hypervelocity binary stars: smoking gun of massive binary black holes

    CERN Document Server

    Lu, Youjun; Lin, D N C

    2007-01-01

    The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

  7. Characterization of durum wheat high molecular weight glutenin subunits Bx20 and By20 sequences by a molecular and proteomic approach.

    Science.gov (United States)

    Santagati, Vito Davide; Sestili, Francesco; Lafiandra, Domenico; D'Ovidio, Renato; Rogniaux, Helene; Masci, Stefania

    2016-07-01

    Wheat high molecular weight glutenin subunit variation is important because of its great influence on glutenin polymer structure, that is related to dough technological properties. Among the different subunits, the pair Bx20 and By20 is known to have a negative effect on quality, but the reasons are not clear: Bx20 has two cysteines, which theoretically make this subunit a chain extender of the glutenin polymer, just like the other Bx subunits, showing four cysteines, two of which should be involved in intra-molecular disulfide bonds. By20 has never been characterized so far at molecular level. Here we report the nucleotide sequences of Bx20 and By20 genes isolated from the durum wheat cultivar 'Lira 45' and the validation of the corresponding deduced amino acid sequences by using MALDI-TOF and LC-MS/MS. Four nucleotide differences were identified in the Bx20 gene with respect to the deduced sequence present in NCBI, causing two amino acid substitutions. For the By20 subunit, nucleotide and amino acid sequences revealed a great similarity to By15, both at gene and protein levels, showing five nucleotide changes generating two amino acid differences. No evidence of post-translational modifications has been found. Hypotheses are formulated in regard to relationships with technological quality. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Milli-arcsecond Binaries

    CERN Document Server

    Torres, R M; Mioduszewki, A; Rodríguez, L F

    2008-01-01

    As part of an astrometric program, we have used the Very Long Baseline Array to measure the trigonometric parallax of several young stars in the Taurus and Ophiuchus star-forming regions with great accuracy. Additionally, we have obtained an unprecedented sample of high-resolution (~ 1 mas) images of several young stellar systems. These images revealed that about 70% of the stars in our sample are very tight binary stars (with separations of a few mas). Since it is highly unlikely that 70% of all stars are such tight binaries, we argue that selection effects are at work.

  9. Binary Cumulant Varieties

    CERN Document Server

    Sturmfels, Bernd

    2011-01-01

    Algebraic statistics for binary random variables is concerned with highly structured algebraic varieties in the space of 2x2x...x2-tensors. We demonstrate the advantages of representing such varieties in the coordinate system of binary cumulants. Our primary focus lies on hidden subset models. Parametrizations and implicit equations in cumulants are derived for hyperdeterminants, for secant and tangential varieties of Segre varieties, and for certain context-specific independence models. Extending work of Rota and collaborators, we explore the polynomial inequalities satisfied by cumulants.

  10. Formation of binary radio pulsars

    International Nuclear Information System (INIS)

    In the framework of the standard scenario of the evolution of massive binary stars a study is made of the formation of final binary systems in which at least one of the components is a neutron star. It is found that about every fortieth radio pulsar must be a member of a close binary system. This is confirmed by observations. Radio pulsars are not formed in wide binary systems, possibly because of the very slow rotation of the presupernova stars

  11. Quantum Binary Symmetric Channels

    Institute of Scientific and Technical Information of China (English)

    陈小余; 仇佩亮

    2001-01-01

    Quantum binary symmetric channels are defined via the invariance of fidelity under unitary transformations ofthe input density operators. In this definition, they not only include the most studied case of the depolarizingchannel but also other channels. We investigate the character of the latter and find the maximum of the coherentinformation to estimate the capacities of the channels.

  12. Equational binary decision diagrams

    NARCIS (Netherlands)

    Groote, J.F.; Pol, J.C. van de

    2000-01-01

    We incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tautology checkin

  13. Cucurmosin induces apoptosis of BxPC-3 human pancreatic cancer cells via inactivation of the EGFR signaling pathway.

    Science.gov (United States)

    Zhang, Baoming; Huang, Heguang; Xie, Jieming; Xu, Chunsen; Chen, Minghuang; Wang, Congfei; Yang, Aiqin; Yin, Qiang

    2012-03-01

    Pancreatic cancer remains the fourth most common cause of cancer-related death in the United States. Potent therapeutic strategies are urgently needed for pancreatic cancer. Cucurmosin is a novel type 1 ribosome-inactivating protein (RIP) isolated from the sarcocarp of Cucurbita moschata (pumpkin). Due to its cytotoxicity, cucurmosin can inhibit tumor cell proliferation through induction of apoptosis on tumor cells, but the specific mechanism is still unclear. We explored the function of cucurmosin in BxPC-3 pancreatic cancer cells using multiple cellular and molecular approaches such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), Western blotting and transmission electron microscopy for observing typical changes and formation of apoptotic bodies. We found that cucurmosin inhibited the proliferation of BxPC-3 cells in a time- and dose-dependent manner, and increased the cell population in the G0-G1 phase. With increasing concentration of cucurmosin, the expression of EGFR, p-PI3K, Akt, p-Akt, mTOR, p-mTOR, P70S6K-α, p-P70S6K-α, 4E-BP1 and p-4E-BP1 at the protein level was decreased, whereas the expression of p-Bad and caspase-9 was elevated. However, the mRNA expression of EGFR did not change. These findings suggest that cucurmosin can down-regulate the expression of EGFR by targeting. Cucurmosin induces the apoptosis of BxPC-3 pancreatic cancer cells via the PI3K/Akt/mTOR signaling pathway.

  14. Hα Line Polarization in the 2B/X4.8 Flare of 2002 July 23

    Institute of Scientific and Technical Information of China (English)

    Zhi Xu; N. M. Firstova; Qing-Rong Chen; Cheng Fang

    2003-01-01

    On 2002 July 23, a 2B/X4.8 flare was observed in the Hα line spec-tropolarimetrically by the Large Solar Vacuum Telescope of Baikal AstrophysicalObservatory. Linear polarization of 3%-10% was detected in the Hα line, particu-larly where the line showed central reversal. The linear polarization is mainly radialon the solar disk and appears at the impulsive phase of the hard X-ray and γ-raybursts. It is limited to some relatively small regions of the flare. The polarizationin a limited small region (~ 4″ - 5″) changed its direction within a short period oftime (~ 10s).

  15. Study on the Method of Rapid and Simultaneous Determination of U(Ⅳ) and U(Ⅵ) in 1BX

    Institute of Scientific and Technical Information of China (English)

    LIU; Huan-liang; WANG; Ling; ZHANG; Li-hua; FAN; De-jun; QIAN; Hong-juan

    2012-01-01

    <正>In Purex process,to separate U and Pu from each other, Pu(Ⅳ) must be reduced to Pu(Ⅲ). As a widely used reductant for Pu(Ⅳ), U(Ⅳ) is prepared by electrolysis of U(Ⅵ) solutions. The concentrations of U(Ⅳ) and U(Ⅵ) directly affect the efficiency of Pu(Ⅳ) reduction. So, the concentrations of U(Ⅳ) and U(Ⅵ) in 1BX must be measured timely. The traditional destructive titrimetry method for U(Ⅳ) and U(Ⅵ)

  16. Expression Analysis of HMW-GS 1Bx14 and 1By15 in Wheat Varieties and Transgenic Research of 1By15 Gene

    Institute of Scientific and Technical Information of China (English)

    XU Tao; ZHANG Xue-yong; DONG Yu-shen

    2006-01-01

    High-molecular-weight glutenin subunits (HMW-GSs), one class of seed storage proteins in wheat, play an important role in determining bread-making quality of flour. More and more proves support that HMW-GS-1Bx14 and -1Bx15 subunits are strongly positively associated with good bread-making and excellent noodle-making quality. The two subunits are encoded by two genes, Glu-1Bx14 and Glu-1Bx15, which are tightly linked and located on the 1BL. Protein assay by SDS-PAGE indicated that the expression of Glu-1Bx14 gene was always much stronger than that of Glu-1By15 in the same variety. But, variation of expression level for Glu-1By15 gene existed among varieties, such as in Xiaoyan 54,Xiaoyan 6, Yanzhan 1 and Shanyou 225. We also investigated the transcription difference of Glu-1By14 and Glu-1By15 genes in Xiaoyan 54 and Shanyou 225 by semi-quantitative RT-PCR method. The Glu-1By14 always transcripts much more than the Glu-1By15. This was basically consistent with the translation difference between the two genes. Promoters of 1Bx14, 1By15, 1By8, 1Dx2 and 1Dy12 were cloned from Xiaoyan 54, Chinese Spring and Aegilops tauschii. Sequence analysis indicated that the HMW-GS genes had high homology at their promoter regions. However, significant difference existed between sequence of 1Bx14 promoter and those of other HMW-GS genes. The transient expression experiment showed that the promoter of 1By15 has lower activity than that of 1Bx14, which was consistent with their transcription level of the two genes in varieties. In addition, transient expression of the gus driven by the promoter (P2) of HMW-GS 1Dx2 gene was higher than by other HMW-GS promoters. Therefore, we constructed 1By15 gene expression vector driven by the 1Dx2 promoter, and transformed the 1By15 gene into wheat commercial variety, Jimai 20 by pollen tube method. Of 45 independent transgenic lines identified by PCR, 3 were confirmed to contain the HMW-GS 1By15 gene via Southern hybridization. The delivered 1By15

  17. Binary MEMS gas sensors

    International Nuclear Information System (INIS)

    A novel sensing mechanism for electrostatic MEMS that employs static bifurcation-based sensing and binary detection is demonstrated. It is implemented as an ethanol vapour sensor that exploits the static pull-in bifurcation. Sensor detection of 5 ppm of ethanol vapour in dry nitrogen, equivalent to a detectable mass of 165 pg, is experimentally demonstrated. Sensor robustness to external disturbances is also demonstrated. A closed-form expression for the sensitivity of statically detected electrostatic MEMS sensors is derived. It is shown that the sensitivity of static bifurcation-based binary electrostatic MEMS sensors represents an upper bound on the sensitivity of static detection for given sensor dimensions and material properties. (paper)

  18. FS CMa type binaries

    CERN Document Server

    Miroshnichenko, Anatoly

    2015-01-01

    FS CMa type stars is a group of ~70 objects formerly known as unclassified stars with the B[e] phenomenon. Their very strong emission-line spectra in combination with a nearly main-sequence luminosity suggest the binary nature for them. They possess strong IR excesses due to radiation of circumstellar dust that implies a compact distribution probably in a circumbinary disk. Our long-term spectroscopic monitoring revealed neutral metal lines, which always include that of Li I 6708 \\AA, in the spectra of some FS CMa objects indicating the presence of a cool star. We present a summary of our results with a first overview of FS CMa type binaries and review possible implications for the nature and evolutionary status of the entire group.

  19. RCRA Assessment Plan for Single-Shell Tank Waste Management Area B-BX-BY at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Narbutovskih, Susan M.

    2006-09-29

    This document was prepared as a groundwater quality assessment plan revision for the single-shell tank systems in Waste Management Area B-BX-BY at the Hanford Site. Groundwater monitoring is conducted at this facility in accordance with 40 CFR Part 265, Subpart F. In FY 1996, the groundwater monitoring program was changed from detection-level indicator evaluation to a groundwater quality assessment program when elevated specific conductance in downgradient monitoring well 299 E33-32 was confirmed by verification sampling. During the course of the ensuing investigation, elevated technetium-99 and nitrate were observed above the drinking water standard at well 299-E33-41, a well located between 241-B and 241-BX Tank Farms. Earlier observations of the groundwater contamination and tank farm leak occurrences combined with a qualitative analysis of possible solutions, led to the conclusion that waste from the waste management area had entered the groundwater and were observed in this well. Based on 40 CFR 265.93 [d] paragraph (7), the owner-operator must continue to make the minimum required determinations of contaminant level and rate/extent of migrations on a quarterly basis until final facility closure. These continued determinations are required because the groundwater quality assessment was implemented prior to final closure of the facility.

  20. Recombinant adenovirus-mediated shRNA silencing of midkine gene in BxPC-3 cells

    Institute of Scientific and Technical Information of China (English)

    Mingyue Xiong; Kunzheng Wang

    2009-01-01

    Objective:To investigate the silencing effects of recombinant adenovirus Ad-shRNA-MK on midkine(MK) gene in pancreatic cancer cells. Methods:Ad-shRNA-MK was used to infect pancreatic cancer BxPC-3 cells. Assays were conducted for knockdown of the MK gene on the day of infection and on the 1a, 3rd, 5th, 7th, and 9th days post-infection by using immunocytochemistry, real-time RT-PCR, and Western blot analysis. Results:The adenoviral Ad-shRNA-PTN was constructed successfully, and infection was confirmed by electron microscopic observation. By using real-time RT-PCR, the inhibition rates of MK mRNA expression in the BxPC-3 cells were 20%, 80%, 55%, and 23% on the 1st, 3rd, 5th, and 7th days post-infection. Immunocytochemistry and Western blot analysis confirmed this effect at the gene product level. Conclusion:Efficient and specific knockdown of MK in pancreatic cancer cells by adenoviral Ad-shRNA-PTN is a potentially powerful tool for the study of gene therapy of pancreatic cancer nerve infiltration.

  1. Headspace vapor characterization of Hanford waste Tank 241-BX-110: Results from samples collected on 04/30/96

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Pool, K.H.; Thomas, B.L.; Olsen, K.B.; Fruchter, J.S.; Silvers, K.L.

    1997-01-01

    This report describes the analytical results of vapor samples taken from the headspace of the waste storage tank 241-BX-110 (Tank BX-110) at the Hanford Site in Washington State. The results described in this report were obtained to characterize the vapors present in the tank headspace and to support safety evaluations and tank farm operations. The results include air concentrations of selected inorganic and organic analytes and grouped compounds from samples obtained by Westinghouse Hanford Company (WHC) and provided for analysis to Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, sample volumes provided by WHC. A summary of the inorganic analytes, permanent gases, and total non-methane organic compounds is listed in a table. The three highest concentration analytes detected in SUMMA{trademark} canister and triple sorbent trap samples are also listed in the table. Detailed descriptions of the analytical results appear in the appendices.

  2. Headspace vapor characterization of Hanford waste Tank 241-BX-110: Results from samples collected on 04/30/96

    International Nuclear Information System (INIS)

    This report describes the analytical results of vapor samples taken from the headspace of the waste storage tank 241-BX-110 (Tank BX-110) at the Hanford Site in Washington State. The results described in this report were obtained to characterize the vapors present in the tank headspace and to support safety evaluations and tank farm operations. The results include air concentrations of selected inorganic and organic analytes and grouped compounds from samples obtained by Westinghouse Hanford Company (WHC) and provided for analysis to Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, sample volumes provided by WHC. A summary of the inorganic analytes, permanent gases, and total non-methane organic compounds is listed in a table. The three highest concentration analytes detected in SUMMA trademark canister and triple sorbent trap samples are also listed in the table. Detailed descriptions of the analytical results appear in the appendices

  3. Binary-Signal Recovery

    Science.gov (United States)

    Griebeler, Elmer L.

    2011-01-01

    Binary communication through long cables, opto-isolators, isolating transformers, or repeaters can become distorted in characteristic ways. The usual solution is to slow the communication rate, change to a different method, or improve the communication media. It would help if the characteristic distortions could be accommodated at the receiving end to ease the communication problem. The distortions come from loss of the high-frequency content, which adds slopes to the transitions from ones to zeroes and zeroes to ones. This weakens the definition of the ones and zeroes in the time domain. The other major distortion is the reduction of low frequency, which causes the voltage that defines the ones or zeroes to drift out of recognizable range. This development describes a method for recovering a binary data stream from a signal that has been subjected to a loss of both higher-frequency content and low-frequency content that is essential to define the difference between ones and zeroes. The method makes use of the frequency structure of the waveform created by the data stream, and then enhances the characteristics related to the data to reconstruct the binary switching pattern. A major issue is simplicity. The approach taken here is to take the first derivative of the signal and then feed it to a hysteresis switch. This is equivalent in practice to using a non-resonant band pass filter feeding a Schmitt trigger. Obviously, the derivative signal needs to be offset to halfway between the thresholds of the hysteresis switch, and amplified so that the derivatives reliably exceed the thresholds. A transition from a zero to a one is the most substantial, fastest plus movement of voltage, and therefore will create the largest plus first derivative pulse. Since the quiet state of the derivative is sitting between the hysteresis thresholds, the plus pulse exceeds the plus threshold, switching the hysteresis switch plus, which re-establishes the data zero to one transition

  4. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  5. Randomized comparison of deliverability and in-hospital complications in implantation of BxSonic(R), Express(R), and Flexmaster(R) coronary stents

    DEFF Research Database (Denmark)

    Thuesen, Leif; Galløe, Anders; Thayssen, Per;

    2005-01-01

    in a native coronary artery were included in the study. There were 494 (664) patients (treated lesions) in the BxSonic(R), 499 (657) in the Express(R) and 500 (658) in the Flexmaster(R) groups. The groups were well matched with regard to age, sex, diabetes, smoking, hypercholesterolemia, hypertension...

  6. Binary optics: Trends and limitations

    Science.gov (United States)

    Farn, Michael W.; Veldkamp, Wilfrid B.

    1993-08-01

    We describe the current state of binary optics, addressing both the technology and the industry (i.e., marketplace). With respect to the technology, the two dominant aspects are optical design methods and fabrication capabilities, with the optical design problem being limited by human innovation in the search for new applications and the fabrication issue being limited by the availability of resources required to improve fabrication capabilities. With respect to the industry, the current marketplace does not favor binary optics as a separate product line and so we expect that companies whose primary purpose is the production of binary optics will not represent the bulk of binary optics production. Rather, binary optics' more natural role is as an enabling technology - a technology which will directly result in a competitive advantage in a company's other business areas - and so we expect that the majority of binary optics will be produced for internal use.

  7. Binaries in the Kuiper Belt

    CERN Document Server

    Noll, K S; Chiang, E I; Margot, J L; Kern, S D; Noll, Keith S.; Grundy, William M.; Chiang, Eugene I.; Margot, Jean-Luc; Kern, Susan D.

    2007-01-01

    Binaries have played a crucial role many times in the history of modern astronomy and are doing so again in the rapidly evolving exploration of the Kuiper Belt. The large fraction of transneptunian objects that are binary or multiple, 48 such systems are now known, has been an unanticipated windfall. Separations and relative magnitudes measured in discovery images give important information on the statistical properties of the binary population that can be related to competing models of binary formation. Orbits, derived for 13 systems, provide a determination of the system mass. Masses can be used to derive densities and albedos when an independent size measurement is available. Angular momenta and relative sizes of the majority of binaries are consistent with formation by dynamical capture. The small satellites of the largest transneptunian objects, in contrast, are more likely formed from collisions. Correlations of the fraction of binaries with different dynamical populations or with other physical variabl...

  8. Bx亚型1例的分子生物学鉴定%Molecular genetic research of a case of Bx subgroup

    Institute of Scientific and Technical Information of China (English)

    刘伟; 李代红; 刘纯

    2011-01-01

    采用标准分析方法分析1例Bx亚型的血清学特征,再采用PCR-SSP技术做ABO初步基因分型,并对ABO基因第6外显子和第7外显子进行测序.该标本血清学检测结果:与抗B反应为无或1+,与抗AB反应为1+或2+,自身不凝集.PCR-SSP结果为Bx02/O2.ABO基因测序结果显示:B基因外显子6出现261G缺失,297为GG纯合子,表明该标本为B型与O2杂合;外显子7直接测序出现297A >G,526C>G,657C>T,703G>A,796C>A,803G>C,905A>G,930A>G,表明该标本为Bx02与O2的杂合;外显子7克隆测序出现803G>C,905A >G,表明该标本为Bx/O2.该标本血清学表型为B型,测序结果与Genbank网站比对鉴定为ABO* Bx.02.1.1与ABO* O21.01.1.1的杂合.%Serologic characters of Bx subtype were analyzed with standard methods, PCR-SSP method was used for its genotype, and DNA sequences of 6 and 7 exons of ABO genes were analyzed by DNA sequencing. Serologically, the anti-B test was no or 1 + , with anti-AB (1 + or 2 + ). The patient's auto antibodies were negative. PCR-SSP showed the patient was Bx02/O2. ABO genetic locus sequencing was 261delG in exon 6 and 297 was GG homozygous. The sample was a combination of blood group B and 02 because 297A > G, 526C > G, 657C > T, 703G > A, 796C > A, 803G >C, 905A >G, 930A > G shown by direct DNA sequencing and 8O3G > C, 905A > G shown by cloning DNA sequencing. The serological phenotype of the specimen was B and the genetic sequence was a combination of ABO * Bx. 02.1.1 and ABO * 021.01.1.1.

  9. Biclustering Sparse Binary Genomic Data

    OpenAIRE

    Van Uitert, M.; Meuleman, W.; Wessels, L. F. A.

    2008-01-01

    Genomic datasets often consist of large, binary, sparse data matrices. In such a dataset, one is often interested in finding contiguous blocks that (mostly) contain ones. This is a biclustering problem, and while many algorithms have been proposed to deal with gene expression data, only two algorithms have been proposed that specifically deal with binary matrices. None of the gene expression biclustering algorithms can handle the large number of zeros in sparse binary matrices. The two propos...

  10. Rotational mixing in close binaries

    CERN Document Server

    de Mink, S E; Langer, N; Yoon, S -Ch; Brott, I; Glebbeek, E; Verkoulen, M; Pols, O R

    2008-01-01

    Rotational mixing is a very important but uncertain process in the evolution of massive stars. We propose to use close binaries to test its efficiency. Based on rotating single stellar models we predict nitrogen surface enhancements for tidally locked binaries. Furthermore we demonstrate the possibility of a new evolutionary scenario for very massive (M > 40 solar mass) close (P < 3 days) binaries: Case M, in which mixing is so efficient that the stars evolve quasi-chemically homogeneously, stay compact and avoid any Roche-lobe overflow, leading to very close (double) WR binaries.

  11. Evolution of Close Binary Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, K; Eggleton, P

    2005-01-24

    We collected data on the masses, radii, etc. of three classes of close binary stars: low-temperature contact binaries (LTCBs), near-contact binaries (NCBs), and detached close binaries (DCBs). They restrict themselves to systems where (1) both components are, at least arguably, near the Main Sequence, (2) the periods are less than a day, and (3) there is both spectroscopic and photometric analysis leading to reasonably reliable data. They discuss the possible evolutionary connections between these three classes, emphasizing the roles played by mass loss and angular momentum loss in rapidly-rotating cool stars.

  12. Low autocorrelation binary sequences

    Science.gov (United States)

    Packebusch, Tom; Mertens, Stephan

    2016-04-01

    Binary sequences with minimal autocorrelations have applications in communication engineering, mathematics and computer science. In statistical physics they appear as groundstates of the Bernasconi model. Finding these sequences is a notoriously hard problem, that so far can be solved only by exhaustive search. We review recent algorithms and present a new algorithm that finds optimal sequences of length N in time O(N {1.73}N). We computed all optimal sequences for N≤slant 66 and all optimal skewsymmetric sequences for N≤slant 119.

  13. Microlensing modulation by binaries

    CERN Document Server

    Dubath, F; Durrer, R; Dubath, Florian; Gasparini, Maria Alice; Durrer, Ruth

    2006-01-01

    We compute the effect of the lens quadrupole on microlensing. The time dependence of the quadrupole can lead to specific modulations of the amplification signal. We study especially binary system lenses in our galaxy. The modulation is observable if the rotation period of the system is smaller than the time over which the amplification is significant and if the impact parameter of the passing light ray is sufficiently close to the Einstein radius so that the amplification is very large. Observations of this modulation can reveal important information on the quadrupole and thus on the gravitational radiation emitted by the lens.

  14. Mesothelin抗体修饰的纳米探针对人胰腺癌细胞BxPC3的体外靶向研究%In vitro study on mesothelin antibody-tagged nanoprobe targeting human pancreatic cell line BxPC3

    Institute of Scientific and Technical Information of China (English)

    卢明智; 乐文俊; 崔少斌; 孙兵妹; 陈炳地; 邵成伟

    2014-01-01

    目的 探讨间皮素(Mesothelin)抗体修饰的荧光纳米Fe3O4@SiO2探针对人胰腺癌细胞BxPC3的靶向性能.方法 经St(o)ber法制备Fe3O4@SiO2磁核,再依次交联CdTe量子点和Mesothelin抗体,获得靶向荧光Fe3O4@SiO2纳米探针.在体外将荧光纳米Fe3O4@SiO2探针与BxPC3细胞共孵育30 min,以低表达Mesothelin的HepG-2和K562细胞作为对照,通过电荷耦合器件(CCD)成像系统和磁分离技术评估探针与癌细胞的靶向吸附性能.结果 制备的荧光纳米Fe3O4@SiO2探针颗粒大小均匀,粒径主要为120 ~ 140 nm.未交联抗体的探针与BxPC3、HepG-2、K562细胞的吸附效率均低于20%,为非特异性吸附.交联Mesothelin抗体的探针与BxPC3、HepG-2、K562细胞的吸附效率分别为(53.9±1.8)%、(8.0±2.1)%、(8.9±2.3)%,其与BxPC3细胞的吸附能力显著提高.结论 Mesothelin抗体修饰的纳米探针可有效识别高表达Mesothelin的BxPC3细胞.%Objective To observe the targeted function of a mesothelin antibody modified nanoprobe in human pancreatic cancer BxPC3 cell.Methods The Fe3O4@SiO2 nanoprobe was prepared by St(o)ber method,and then quantum dots (CdTe) and mesothelin antibody was crosslinked to obtain the properties of targeting and fluorescent.Fluorescent nano Fe3O4@SiO2 probes and BxPC3 cells were incubated in vitro for 30 min.Its targeting performance was tested by the CCD imaging system and magnetic separation technology.HepG-2 and K562 cells with low expression of mesothelin were selected as reference cells.Results This preparation method of nanoprobe could produce a uniform and narrow distribution particle with particle size mainly ranging from 120 to 140 nm.The cell adsorption experiments showed that the adsorption efficiency of BxPC3,HepG-2 and K562 by nanoprobe without crosslinking antibody were less than 20%,as a non-specific adsorption; and the adsorption efficiency of BxPC3,HepG-2 and K562 by crosslinking mesothelin antibody nanoprobe were (53.9

  15. Characterization of Direct-Push Vadose Zone Sediments from the 241-B and 241-BX Tank Farms

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Christopher F.; Icenhower, Jonathan P.; Um, Wooyong; Bjornstad, Bruce N.; Valenta, Michelle M.; Iovin, Cristian; Lanigan, David C.; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

    2007-12-21

    Geochemical tests provide evidence for the transit of a plume of caustic waste solution through the sediment column at the Hanford 241-B and -BX Tank Farms. Direct-push samples recovered from boreholes surrounding Tanks 241-B-110 and 241-BX-102 and related waste transfer lines and diversion boxes included sediments typical of those previously recovered from other localities on the Hanford Site. The Hanford formation sediments are dominantly quartzo-feldspathic sands strewn with lithic fragments, displaying a range of particle size distributions and sorting characteristics. Some moderately well-sorted, fine-grained lithologies are interpreted as lenticular bodies irregularly dispersed in coarser-grained, more poorly sorted sediments. Tier I tests conducted on the vadose zone sediments revealed an inverse correlation between moisture content and sediment size fraction (i.e., there is greater moisture content in finer-grained sediments). The Tier I tests also showed that the pore water solutions were likely sodium-rich, moderately saline, and possessed higher pH values than background (untainted) sediments. These data are characteristic of sediments that have encountered sodium-rich, saline, caustic waste solution, as documented in other reports at other suspect contamination sites around Hanford. Analyses of solutions from 1:1 water extracts reveal relatively balanced cation and anion concentrations, indicating that most of the geochemical species have been accounted for. The water extract data for affected sediments also indicate unusually high concentrations of aluminum, iron, and phosphorus. The relatively high concentrations of aluminum and iron may be the result of dissolution of secondary amorphous phases that precipitated after a reactive plume partially dissolved aluminum- and iron-bearing phases as it migrated through the sediment column. On the other hand, the presence of elevated concentrations of phosphorous may be the tell-tale signature of wastes

  16. Modeling Binary Neutron Stars

    Science.gov (United States)

    Park, Conner; Read, Jocelyn; Flynn, Eric; Lockett-Ruiz, Veronica

    2016-03-01

    Gravitational waves, predicted by Einstein's Theory of Relativity, are a new frontier in astronomical observation we can use to observe phenomena in the universe. Laser Interferometer Gravitational wave Observatory (LIGO) is currently searching for gravitational wave signals, and requires accurate predictions in order to best extract astronomical signals from all other sources of fluctuations. The focus of my research is in increasing the accuracy of Post-Newtonian models of binary neutron star coalescence to match the computationally expensive Numerical models. Numerical simulations can take months to compute a couple of milliseconds of signal whereas the Post-Newtonian can generate similar signals in seconds. However the Post-Newtonian model is an approximation, e.g. the Taylor T4 Post-Newtonian model assumes that the two bodies in the binary neutron star system are point charges. To increase the effectiveness of the approximation, I added in tidal effects, resonance frequencies, and a windowing function. Using these observed effects from simulations significantly increases the Post-Newtonian model's similarity to the Numerical signal.

  17. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Benacquista Matthew J.

    2006-02-01

    Full Text Available The galactic population of globular clusters are old, dense star systems, with a typical cluster containing 10^4 - 10^7 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  18. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    XuChengqian; ZhaoXiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP)is proposed .A new class of block design-Difference Family Pair (DFP)is also proposed .The relationship between PCSP and DFP,the properties and exising conditions of PCSP and the recursive constructions for PCSP are given.

  19. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    Xu Chengqian; Zhao Xiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP) is proposed. A new class of block design-Difference Family Pair (DFP) is also proposed.The relationship between PCSP and DFP, the properties and existing conditions of PCSP and the recursive constructions for PCSP are given.

  20. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  1. Groundwater quality assessment plan for single-shell waste management area B-BX-BY at the Hanford Site

    International Nuclear Information System (INIS)

    Pacific Northwest National Laboratory conducted a first determination groundwater quality assessment at the Hanford Site. This work was performed for the US Department of Energy, Richland Operations Office, in accordance with the Federal Facility Compliance Agreement during the time period 1996--1998. The purpose of the assessment was to determine if waste from the Single-Shell Tank (SST) Waste Management Area (WMA) B-BX-BY had entered the groundwater at levels above the drinking water standards (DWS). The resulting assessment report documented evidence demonstrating that waste from the WMA has, most likely, impacted groundwater quality. Based on 40 CFR 265.93 [d] paragraph (7), the owner-operator must continue to make the minimum required determinations of contaminant level and of rate/extent of migrations on a quarterly basis until final facility closure. These continued determinations are required because the groundwater quality assessment was implemented prior to final closure of the facility

  2. Groundwater quality assessment plan for single-shell waste management area B-BX-BY at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    SM Narbutovskih

    2000-03-31

    Pacific Northwest National Laboratory conducted a first determination groundwater quality assessment at the Hanford Site. This work was performed for the US Department of Energy, Richland Operations Office, in accordance with the Federal Facility Compliance Agreement during the time period 1996--1998. The purpose of the assessment was to determine if waste from the Single-Shell Tank (SST) Waste Management Area (WMA) B-BX-BY had entered the groundwater at levels above the drinking water standards (DWS). The resulting assessment report documented evidence demonstrating that waste from the WMA has, most likely, impacted groundwater quality. Based on 40 CFR 265.93 [d] paragraph (7), the owner-operator must continue to make the minimum required determinations of contaminant level and of rate/extent of migrations on a quarterly basis until final facility closure. These continued determinations are required because the groundwater quality assessment was implemented prior to final closure of the facility.

  3. Research Update: Magnetic phase diagram of EuTi1−xBxO3 (B = Zr, Nb

    Directory of Open Access Journals (Sweden)

    Ling Li

    2014-11-01

    Full Text Available We report the magnetic phase diagram of EuTi1−xBxO3 (B = Zr, Nb, determined from magnetization and heat capacity measurements. Upon Zr-doping, the antiferromagnetic ordering temperature TN of EuTi1−xZrxO3 gradually decreases from 5.6 K (x = 0 to 4.1 K (x = 1. Whereas a similar decrease in TN is observed for small amounts of Nb doping (x ≤ 0.05, ferromagnetism is induced in EuTi1−xNbxO3 with x > 0.05. The ferromagnetic interaction between localized Eu 4f spins mediated by itinerant electrons introduced by Nb doping results in the ferromagnetism in EuTi1−xNbxO3.

  4. Signature Visualization of Software Binaries

    Energy Technology Data Exchange (ETDEWEB)

    Panas, T

    2008-07-01

    In this paper we present work on the visualization of software binaries. In particular, we utilize ROSE, an open source compiler infrastructure, to pre-process software binaries, and we apply a landscape metaphor to visualize the signature of each binary (malware). We define the signature of a binary as a metric-based layout of the functions contained in the binary. In our initial experiment, we visualize the signatures of a series of computer worms that all originate from the same line. These visualizations are useful for a number of reasons. First, the images reveal how the archetype has evolved over a series of versions of one worm. Second, one can see the distinct changes between version. This allows the viewer to form conclusions about the development cycle of a particular worm.

  5. Planets in evolved binary systems

    CERN Document Server

    Perets, Hagai B

    2010-01-01

    Exoplanets are typically thought to form in protoplanetary disks left over from protostellar disk of their newly formed host star. However, additional planetary formation and evolution routes may exist in old evolved binary systems. Here we discuss the implications of binary stellar evolution on planetary systems. In these binary systems stellar evolution could lead to the formation of symbiotic stars, where mass is lost from one star and could be transferred to its binary companion, and may form an accretion disk around it. This raises the possibility that such a disk could provide the necessary environment for the formation of a new, second generation of planets in both circumstellar or circumbinary configurations. Pre-existing first generation planets surviving the post-MS evolution of such systems would be dynamically effected by the mass loss in the systems and may also interact with the newly formed disk. Second generation planetary systems should be typically found in white dwarf binary systems, and ma...

  6. Pairing mechanisms for binary stars

    CERN Document Server

    Kouwenhoven, M B N; Goodwin, S P; Zwart, S F Portegies; Kaper, L; 10.1002/asna.200811061

    2008-01-01

    Knowledge of the binary population in stellar groupings provides important information about the outcome of the star forming process in different environments. Binarity is also a key ingredient in stellar population studies and is a prerequisite to calibrate the binary evolution channels. In these proceedings we present an overview of several commonly used methods to pair individual stars into binary systems, which we refer to as the pairing function. Many pairing functions are frequently used by observers and computational astronomers, either for the mathematical convenience, or because they roughly describe the expected outcome of the star forming process. We discuss the consequences of each pairing function for the interpretation of observations and numerical simulations. The binary fraction and mass ratio distribution generally depend strongly on the selection of the range in primary spectral type in a sample. These quantities, when derived from a binary survey with a mass-limited sample of target stars, ...

  7. Towards Physarum Binary Adders

    CERN Document Server

    Jones, Jeff; 10.1016/j.biosystems.2010.04.005

    2010-01-01

    Plasmodium of \\emph{Physarum polycephalum} is a single cell visible by unaided eye. The plasmodium's foraging behaviour is interpreted in terms of computation. Input data is a configuration of nutrients, result of computation is a network of plasmodium's cytoplasmic tubes spanning sources of nutrients. Tsuda et al (2004) experimentally demonstrated that basic logical gates can be implemented in foraging behaviour of the plasmodium. We simplify the original designs of the gates and show --- in computer models --- that the plasmodium is capable for computation of two-input two-output gate $ \\to $ and three-input two-output $ \\to $. We assemble the gates in a binary one-bit adder and demonstrate validity of the design using computer simulation.

  8. Stability of binaries. Part II: Rubble-pile binaries

    Science.gov (United States)

    Sharma, Ishan

    2016-10-01

    We consider the stability of the binary asteroids whose members are granular aggregates held together by self-gravity alone. A binary is said to be stable whenever both its members are orbitally and structurally stable to both orbital and structural perturbations. To this end, we extend the stability analysis of Sharma (Sharma [2015] Icarus, 258, 438-453), that is applicable to binaries with rigid members, to the case of binary systems with rubble members. We employ volume averaging (Sharma et al. [2009] Icarus, 200, 304-322), which was inspired by past work on elastic/fluid, rotating and gravitating ellipsoids. This technique has shown promise when applied to rubble-pile ellipsoids, but requires further work to settle some of its underlying assumptions. The stability test is finally applied to some suspected binary systems, viz., 216 Kleopatra, 624 Hektor and 90 Antiope. We also see that equilibrated binaries that are close to mobilizing their maximum friction can sustain only a narrow range of shapes and, generally, congruent shapes are preferred.

  9. Headspace vapor characterization of Hanford Waste Tank 241-BX-107: Results from samples collected on November 17, 1995. Tank Vapor Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Thomas, B.L.; Pool, K.H. [and others

    1996-06-01

    This report describes the results of vapor samples taken from the headspace of waste storage tank 241-BX-107 (Tank BX-107) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was {open_quotes}Vapor Sampling and Analysis Plan{close_quotes}, and the sample job was designated S5080. Samples were collected by WHC on November 17, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace.

  10. Tank Vapor Characterization Project: Headspace vapor characterization of Hanford Waste Tank 241-BX-105: Results from samples collected on 04/24/96

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B.L.; Evans, J.C.; Pool, K.H. [and others

    1997-01-01

    This report describes the analytical results of vapor samples taken from the headspace of the waste storage tank 241-BX-105 (Tank BX-105) at the Hanford Site in Washington State. The results described in this report were obtained to characterize the vapors present in the tank headspace and to support safety evaluations and tank farm operations. The results include air concentrations of selected inorganic and organic analytes and grouped compounds from samples obtained by Westinghouse Hanford Company (WHC) and provided for analysis to Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, on sample volumes provided by WHC. A summary of the inorganic analytes, permanent gases, and total non-methane organic compounds is listed in Table S.1. Detailed descriptions of the analytical results appear in the appendices.

  11. Simulating relativistic binaries with Whisky

    Science.gov (United States)

    Baiotti, L.

    We report about our first tests and results in simulating the last phase of the coalescence and the merger of binary relativistic stars. The simulations were performed using our code Whisky and mesh refinement through the Carpet driver.

  12. Binary nucleation beyond capillarity approximation

    NARCIS (Netherlands)

    Kalikmanov, V.I.

    2010-01-01

    Large discrepancies between binary classical nucleation theory (BCNT) and experiments result from adsorption effects and inability of BCNT, based on the phenomenological capillarity approximation, to treat small clusters. We propose a model aimed at eliminating both of these deficiencies. Adsorption

  13. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  14. Discs in misaligned binary systems

    CERN Document Server

    Rawiraswattana, Krisada; Goodwin, Simon P

    2016-01-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-...

  15. Cryptography with DNA binary strands.

    Science.gov (United States)

    Leier, A; Richter, C; Banzhaf, W; Rauhe, H

    2000-06-01

    Biotechnological methods can be used for cryptography. Here two different cryptographic approaches based on DNA binary strands are shown. The first approach shows how DNA binary strands can be used for steganography, a technique of encryption by information hiding, to provide rapid encryption and decryption. It is shown that DNA steganography based on DNA binary strands is secure under the assumption that an interceptor has the same technological capabilities as sender and receiver of encrypted messages. The second approach shown here is based on steganography and a method of graphical subtraction of binary gel-images. It can be used to constitute a molecular checksum and can be combined with the first approach to support encryption. DNA cryptography might become of practical relevance in the context of labelling organic and inorganic materials with DNA 'barcodes'.

  16. Results of phase 1 groundwater quality assessment for Single-Shell Tank Waste Management Areas B-BX-BY at the Hanford Site

    International Nuclear Information System (INIS)

    Pacific Northwest National Laboratory conducted a Phase 1 (or first determination) groundwater quality assessment for the US Department of Energy, Richland Operations Office, in accordance with the Federal Facility Compliance Agreement. The purpose of the assessment was to determine if the Single-Shell Tank Waste Management Area (WMA) B-BX-BY has impacted groundwater quality. This report will document the evidence demonstrating that the WMA has impacted groundwater quality

  17. AN IMPROVED DESIGN OF REVERSIBLE BINARY TO BINARY CODED DECIMAL CONVERTER FOR BINARY CODED DECIMAL MULTIPLICATION

    Directory of Open Access Journals (Sweden)

    Praveena Murugesan

    2014-01-01

    Full Text Available Reversible logic gates under ideal conditions produce zero power dissipation. This factor highlights the usage of these gates in optical computing, low power CMOS design, quantum optics and quantum computing. The growth of decimal arithmetic in various applications as stressed the need to propose the study on reversible binary to BCD converter which plays a greater role in decimal multiplication for providing faster results. The different parameters such as gate count,garbage output and constant input are more optimized in the proposed fixed bit binary to binary coded decimal converter than the existing design.

  18. Transient Black Hole Binaries

    CERN Document Server

    Belloni, T M

    2016-01-01

    The last two decades have seen a great improvement in our understand- ing of the complex phenomenology observed in transient black-hole binary systems, especially thanks to the activity of the Rossi X-Ray Timing Explorer satellite, com- plemented by observations from many other X-ray observatories and ground-based radio, optical and infrared facilities. Accretion alone cannot describe accurately the intricate behavior associated with black-hole transients and it is now clear that the role played by different kinds of (often massive) outflows seen at different phases of the outburst evolution of these systems is as fundamental as the one played by the accretion process itself. The spectral-timing states originally identified in the X-rays and fundamentally based on the observed effect of accretion, have acquired new importance as they now allow to describe within a coherent picture the phenomenology observed at other wave- length, where the effects of ejection processes are most evident. With a particular focu...

  19. Binary nucleation beyond capillarity approximation

    OpenAIRE

    Kalikmanov, V.I.

    2010-01-01

    Large discrepancies between binary classical nucleation theory (BCNT) and experiments result from adsorption effects and inability of BCNT, based on the phenomenological capillarity approximation, to treat small clusters. We propose a model aimed at eliminating both of these deficiencies. Adsorption is taken into account within Gibbsian approximation. Binary clusters are treated by means of statistical-mechanical considerations: tracing out the molecular degrees of freedom of the more volatil...

  20. Clostridium difficile binary toxin CDT

    OpenAIRE

    Gerding, Dale N.; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

    2013-01-01

    Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylatio...

  1. Coalescence of Binary Neutron Stars

    OpenAIRE

    Oohara, Ken-ichi; Namamura, Takashi

    1996-01-01

    The most important sources for laser-interferometric gravitational-wave detectors like LIGO or VIRGO are catastrophic events such as coalescence of a neutron-star binary. The final phase, or the last three milliseconds, of coalescence is considered. We describe results of numerical simulations of coalescing binary neutron stars using Newtonian and post-Newtonian hydrodynamics code and then discuss recent development of our 3D GR code.

  2. Coevolution of Binaries and Gaseous Discs

    CERN Document Server

    Fleming, David P

    2016-01-01

    The recent discoveries of circumbinary planets by $\\it Kepler$ raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disc, and how the disc and binary interact and change as a result. The central binary excites resonances in the surrounding protoplanetary disc that drive evolution in both the binary orbital elements and in the disc. To probe how these interactions impact binary eccentricity and disc structure evolution, N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary discs surrounding binaries based on Kepler 38 were run for $10^4$ binary periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disc via a parametric instability and excite disc eccentricity growth. Eccentric binaries strongly couple to the disc causing eccentricity growth for both the disc and binary. Discs around sufficiently eccentri...

  3. Tank Vapor Characterization Project: Tank 241-BX-103 headspace gas and vapor characterization results from samples collected on August 1, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Pool, K.H.; Thomas, B.L.; Sklarew, D.S.; Edwards, J.A. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from headspace of waste storage tank 241-BX-103 (Tank BX-103) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-103 headspace, determined to be present at approximately 0.385% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.633% if the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  4. Tank vapor characterization project: Tank 241-BX-104 fifth temporal study: Headspace gas and vapor characterization results from samples collected on June 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, J.C.; Pool, K.H.; Evans, J.C.; Olsen, K.B. [and others

    1997-07-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-104 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.270% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.675% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  5. Tank 241-BX-104 third temporal study: Headspace gas and vapor characterization results from samples collected on February 6, 1997. Tank vapor characterization project

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Pool, K.H.; Hayes, J.C. [and others

    1997-09-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-104 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.178 % of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.458% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  6. Tank Vapor Characterization Project: Tank 241-BX-106 headspace gas and vapor characterization results from samples collected on August 15, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Evans, J.C.; Thomas, B.L.; Edwards, J.A.; Julya, J.L. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-106 (Tank BX-106) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and analysis plan. Ammonia was the principal flammable constituent of the Tank BX-106 headspace, determined to be present at approximately 0.031% of it lower flammability limit (LFL). Total headspace flammability was estimated to be <0.143% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  7. Tank Vapor Characterization Project: Tank 241-BX-104 second temporal study headspace gas and vapor characterization results from samples collected on December 12, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Evans, J.C.; Hayes, J.C.; Olsen, K.B. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-104 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.248% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.645% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  8. Tank 241-BX-104 fourth temporal study: Headspace gas and vapor characterization results from samples collected on April 7, 1997. Tank vapor characterization project

    Energy Technology Data Exchange (ETDEWEB)

    Mitroshkov, A.V.; Hayes, J.C.; Evans, J.C. [and others

    1997-09-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-04 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.208% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.536% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  9. Tank Vapor Characterization Project: Tank 241-BX-111 headspace gas and vapor characterization results from samples collected on August 27, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Evans, J.C.; Thomas, B.L.; Sklarew, D.S. Edwards, J.A. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-111 (Tank BX-111) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and analysis plan (SAP). Ammonia was the principal flammable constituent of the Tank BX-111 headspace, determined to be present at approximately 0.042 of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.157% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  10. Tank Vapor Characterization Project: Tank 241-BX-104 headspace gas and vapor characterization results from samples collected on August 22, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Pool, K.H.; Thomas, B.L.; Olsen, K.B.; Julya, J.L. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-104 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analyses plan (SAP). Total non-methane organic compounds was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.310% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.784% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  11. Tank Vapor Characterization Project: Tank 241-BX-102 headspace gas and vapor characterization results from samples collected on July 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Evans, J.C.; Thomas, B.L.; Olsen, K.B. Edwards, J.A. [and others

    1997-08-01

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-102 (Tank BX-102) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and and analysis plan. Ammonia and TNMOCs were the principal flammable constituents of the Tank BX-102 headspace, each determined to be present at approximately 0.002% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.107% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.

  12. Mechanical properties of hybrid organic-inorganic CH3NH3BX3 (B = Sn, Pb; X = Br, I perovskites for solar cell absorbers

    Directory of Open Access Journals (Sweden)

    Jing Feng

    2014-08-01

    Full Text Available The crystal structures, elastic and anisotropic properties of CH3NH3BX3 (B = Sn, Pb; X = Br, I compounds as solar cell absorber layers are investigated by the first-principles calculations. The type and strength of chemical bond B-X are found to determine the elastic properties. B-X bonds and the organic cations are therefore crucial to the functionalities of such absorbers. The bulk, shear, Young's modulus ranges from 12 to 30 GPa, 3 to 12 GPa, and 15 to 37 GPa, respectively. Moreover, the interaction among organic and inorganic ions would have negligible effect for elastic properties. The B/G and Poisson's ratio show it would have a good ductile ability for extensive deformation as a flexible/stretchable layer on the polymer substrate. The main reason is attributed to the low shear modulus of such perovskites. The anisotropic indices AU, AB AG, A1, A2, and A3 show ABX3 perovskite have very strong anisotropy derived from the elastic constants, chemical bonds, and symmetry.

  13. Tank 241-BX-104 fourth temporal study: Headspace gas and vapor characterization results from samples collected on April 7, 1997. Tank vapor characterization project

    International Nuclear Information System (INIS)

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-04 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.208% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.536% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0

  14. Tank Vapor Characterization Project: Tank 241-BX-104 second temporal study headspace gas and vapor characterization results from samples collected on December 12, 1996

    International Nuclear Information System (INIS)

    This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-BX-104 (Tank BX-104) at the Hanford Site in Washington State. Tank headspace samples collected by SGN Eurisys Service Corporation (SESC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample provided by SESC. Ammonia was determined to be above the immediate notification limit specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-104 headspace, determined to be present at approximately 0.248% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.645% of the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0

  15. Unsupervised learning of binary vectors

    Science.gov (United States)

    Copelli Lopes da Silva, Mauro

    In this thesis, unsupervised learning of binary vectors from data is studied using methods from Statistical Mechanics of disordered systems. In the model, data vectors are distributed according to a single symmetry-breaking direction. The aim of unsupervised learning is to provide a good approximation to this direction. The difference with respect to previous studies is the knowledge that this preferential direction has binary components. It is shown that sampling from the posterior distribution (Gibbs learning) leads, for general smooth distributions, to an exponentially fast approach to perfect learning in the asymptotic limit of large number of examples. If the distribution is non-smooth, then first order phase transitions to perfect learning are expected. In the limit of poor performance, a second order phase transition ("retarded learning") is predicted to occur if the data distribution is not biased. Using concepts from Bayesian inference, the center of mass of the Gibbs ensemble is shown to have maximal average (Bayes-optimal) performance. This upper bound for continuous vectors is extended to a discrete space, resulting in the clipped center of mass of the Gibbs ensemble having maximal average performance among the binary vectors. To calculate the performance of this best binary vector, the geometric properties of the center of mass of binary vectors are studied. The surprising result is found that the center of mass of infinite binary vectors which obey some simple constraints, is again a binary vector. When disorder is taken into account in the calculation, however, a vector with continuous components is obtained. The performance of the best binary vector is calculated and shown to always lie above that of Gibbs learning and below the Bayes-optimal performance. Making use of a variational approach under the replica symmetric ansatz, an optimal potential is constructed in the limits of zero temperature and mutual overlap 1. Minimization of this potential

  16. Binary Encodings of Non-binary Constraint Satisfaction Problems: Algorithms and Experimental Results

    CERN Document Server

    Samaras, N; 10.1613/jair.1776

    2011-01-01

    A non-binary Constraint Satisfaction Problem (CSP) can be solved directly using extended versions of binary techniques. Alternatively, the non-binary problem can be translated into an equivalent binary one. In this case, it is generally accepted that the translated problem can be solved by applying well-established techniques for binary CSPs. In this paper we evaluate the applicability of the latter approach. We demonstrate that the use of standard techniques for binary CSPs in the encodings of non-binary problems is problematic and results in models that are very rarely competitive with the non-binary representation. To overcome this, we propose specialized arc consistency and search algorithms for binary encodings, and we evaluate them theoretically and empirically. We consider three binary representations; the hidden variable encoding, the dual encoding, and the double encoding. Theoretical and empirical results show that, for certain classes of non-binary constraints, binary encodings are a competitive op...

  17. 莱姆病螺旋体重组质粒pBX1的DNA序列分析及其在大肠杆菌中的诱导表达%DNA Sequence Analysis and Expression of the Recombinant Plasmid pBX1 from Borrelia Burgdorferi B31 Strain

    Institute of Scientific and Technical Information of China (English)

    谢勇恩; 鲍朗; 胡昌华; 李学敏; 陈炜

    2001-01-01

    目的为莱姆病血清学诊断和基因工程亚单位疫苗研制提供靶抗原。方法采用377型DNA自动测序仪对莱姆病螺旋体重组质粒pBX1的插入片段进行DNA序列测定,并通过计算机软件对其进行限制性内切酶酶谱分析。然后将重组质粒pBX1在大肠杆菌中进行诱导表达,并对其表达产物进行免疫印迹分析。结果①重组质粒pBX1插入片段大小为477bp,其核苷酸序列与文献报道的p83基因全序列相应区段相比较仅有一个碱基的变异,②成功绘制了该插入片段的限制性内切酶酶谱;③重组质粒在大肠杆菌中诱导表达后获得了29kd的融合蛋白;④Western-blotting分析表明该融合蛋白能与莱姆病多价抗血清呈强阳性印迹反应。结论该研究成功地对莱姆病螺旋体83kd抗原蛋白特异性区段进行了基因重组和表达,为进一步研究其在莱姆病血清学诊断和基因工程亚单位疫苗研制中的应用奠定了基础。%Objective This study was to provide the target antigen for the development of a Lyme disease vaccine and serodiagnosis reagent.Methods We used the automatic DNA sequencing machine (Model 377) to detect the nucleotide sequence of the inserted part of the recombinant plasmid pBX1 from Borrelia burgdorferi B31 strain. The restriction enzyme map of the inserted part of pBX1 was analysed by using computer software. The expressed product of pBX1 in E.coli XLI-Blue MRF′ was analysed by using SDS-PAGE and western-blotting. Results ①DNA sequencing showed that pBX1 contained a 477bp inserted gene fragment,and when it was compared with the published sequence of the specific region of the gene of the 83kd antigen protein from Borrelia burgdorferi B31 strain,only one amino acid codon was different.②The restriction enzyme map of the inserted part of pBX1 was successfully constructed.③The recombinant plasmid pBX1 expressed a 29kd fusion protein in E.coli XL1-Blue MRF

  18. 冬凌草甲素对胰腺癌BxPC-3细胞Cyclin D/Rb/p16信号蛋白的影响研究%Study on Cyclin D/Rb/p16 Signal Pathway of BxPC-3 Cell Line Treated with Oridonin

    Institute of Scientific and Technical Information of China (English)

    沈雯; 许健; 孙金权; 牟一平; 吴晓莉

    2013-01-01

    Objective]To observe variety of morphological features, DNA band and expressions of Cyclin D/RB/p16 genes in BxPC-3 cel s treated with oridonin, investigate relationship between oridonin-induced apoptosis and Cyclin D/Rb/p16 signal pathway, which provided oridonin not only possible anti-tumor accesses but also favourable clinical data. [Methods]BxPC-3 cel s morphology was observed by Wright's staining, apoptosis was assayed by Hoechst 33258 fluorescence staining after treated with Oridonin in vitro, Cyclin D/Rb/P16 signal genes expression of BxPC-3 cel s were detected using real time PCR and a PCR kit specific of methylation for p16 gene methylation.[Results]Wright's staining showed characteristic apoptotic body in BxPC-3 cel s, Hoechst 33258 fluorescence staining showed characteristic change of apoptosis, the expression of CDK4 reduced to the minimum, and p16 gene reached the maximum; p16 gene presented methylation after treated with oridonin for 36h in BxPC-3 cel s. [Conclusion]1. Oridonin could induce BxPC-3 cel s into apoptosis. 2. Oridonin down-regulated CDK4, and up-regulated p16 and the methylation of p16 gene in BxPC-3 cel , but without effect on p16 gene methylation, which suggested that oridonin inhibited pancreatic cancer through Cyclin D/Rb/p16 signal pathway to a certain extent.%  [目的]通过观察冬凌草甲素对胰腺癌BxPC-3细胞形态和DNA变化的影响,研究其对Cyclin D/Rb/p16信号通路中基因表达的调节作用,分析冬凌草甲素对胰腺癌BxPC-3细胞的诱导与Cyclin D/Rb/p16信号通路之间的内在联系,为冬凌草甲素抗肿瘤提供可能的途径,为临床使用提供有利数据。[方法]冬凌草甲素作用BxPC-3细胞后,经瑞氏染色和Hoechst 33258荧光染色观察细胞形态,RT-PCR和实时荧光定量法(real time PCR)检测Cyclin D/Rb/p16信号通路基因的表达变化;甲基化专一性PCR试剂盒检测p16基因的甲基化。[结果]冬凌草甲素(32μg·mL-1)作用于Bx

  19. Study on Cyclin D/Rb/p16 Signal Pathway of BxPC-3 Cell Line Treated with Oridonin%冬凌草甲素对胰腺癌BxPC-3细胞Cyclin D/Rb/p16信号蛋白的影响研究

    Institute of Scientific and Technical Information of China (English)

    沈雯; 许健; 孙金权; 牟一平; 吴晓莉

    2013-01-01

      [目的]通过观察冬凌草甲素对胰腺癌BxPC-3细胞形态和DNA变化的影响,研究其对Cyclin D/Rb/p16信号通路中基因表达的调节作用,分析冬凌草甲素对胰腺癌BxPC-3细胞的诱导与Cyclin D/Rb/p16信号通路之间的内在联系,为冬凌草甲素抗肿瘤提供可能的途径,为临床使用提供有利数据。[方法]冬凌草甲素作用BxPC-3细胞后,经瑞氏染色和Hoechst 33258荧光染色观察细胞形态,RT-PCR和实时荧光定量法(real time PCR)检测Cyclin D/Rb/p16信号通路基因的表达变化;甲基化专一性PCR试剂盒检测p16基因的甲基化。[结果]冬凌草甲素(32μg·mL-1)作用于BxPC-3细胞后,瑞氏染色可见细胞出现典型的凋亡小体,Hoechst33258荧光染色可见BxPC-3细胞出现特征性凋亡变化,冬凌草甲素(32μg·mL-1)作用BxPC-3细胞36 h时,CDK4的表达量达到最低,但p16的表达量达到最高;p16基因有甲基化。[结论]1、冬凌草甲素能诱导BxPC-3细胞形态改变。2、冬凌草甲素在一定程度下调了CDK4基因的表达,上调了p16基因的表达,不能改变p16基因的甲基化,可能通过影响Cyclin D/Rb/p16信号通路而抑制胰腺癌的生长周期。%Objective]To observe variety of morphological features, DNA band and expressions of Cyclin D/RB/p16 genes in BxPC-3 cel s treated with oridonin, investigate relationship between oridonin-induced apoptosis and Cyclin D/Rb/p16 signal pathway, which provided oridonin not only possible anti-tumor accesses but also favourable clinical data. [Methods]BxPC-3 cel s morphology was observed by Wright's staining, apoptosis was assayed by Hoechst 33258 fluorescence staining after treated with Oridonin in vitro, Cyclin D/Rb/P16 signal genes expression of BxPC-3 cel s were detected using real time PCR and a PCR kit specific of methylation for p16 gene methylation.[Results]Wright's staining showed characteristic apoptotic body in BxPC-3 cel s

  20. Airy function approach and Numerov method to study the anharmonic oscillator potentials V(x = Ax2α + Bx2

    Directory of Open Access Journals (Sweden)

    N. Al Sdran

    2016-06-01

    Full Text Available The numerical solutions of the time independent Schrödinger equation of different one-dimensional potentials forms are sometime achieved by the asymptotic iteration method. Its importance appears, for example, on its efficiency to describe vibrational system in quantum mechanics. In this paper, the Airy function approach and the Numerov method have been used and presented to study the oscillator anharmonic potential V(x = Ax2α + Bx2, (A>0, B<0, with (α = 2 for quadratic, (α =3 for sextic and (α =4 for octic anharmonic oscillators. The Airy function approach is based on the replacement of the real potential V(x by a piecewise-linear potential v(x, while, the Numerov method is based on the discretization of the wave function on the x-axis. The first energies levels have been calculated and the wave functions for the sextic system have been evaluated. These specific values are unlimited by the magnitude of A, B and α. It’s found that the obtained results are in good agreement with the previous results obtained by the asymptotic iteration method for α =3.

  1. Deteccion Y Estudio De Rayos Cosmicos Y Su Efecto Ionizante En Sales Del Tipo A(2)bx(4) (spanish Text)

    CERN Document Server

    Ninco Ninco, L A

    2003-01-01

    The objective of this research was to detect and to study the ionizing effect of cosmic rays in crystals of the type A2BX4, specifically Cs2CoCl4, Cs2ZnI4 doped to 2% with Mn by weigh and Cs2ZnCl4 pure and doped to 0.5% with Mn by weight, that were grown by slow evaporation. They were selected after making tests of sensitivity to the electromagnetic and radio waves in a RLC circuit. They were also characterized by X-ray diffraction to establish their structure type and family. Once selected they were used to construct a device or detector system. The detectors with crystals presented signals in a range of voltage between 400 and 1800V. Graphs of the count versus voltage were constructed, it was observed that these crystals passed through zones in which the behavior of the crystals due to the ionizing effect of particles that go through can be determined when a high voltage is applied to them. These crystals present a plateau that makes them ideal for detection of particles. The measurements were done at room ...

  2. Binaries and Globular Cluster Dynamics

    CERN Document Server

    Rasio, F A; Joshi, K J; Rasio, Frederic A.; Fregeau, John M.; Joshi, Kriten J.

    2001-01-01

    We summarize the results of recent theoretical work on the dynamical evolution of globular clusters containing primordial binaries. Even a very small initial binary fraction (e.g., 10%) can play a key role in supporting a cluster against gravothermal collapse for many relaxation times. Inelastic encounters between binaries and single stars or other binaries provide a very significant energy source for the cluster. These dynamical interactions also lead to the production of large numbers of exotic systems such as ultracompact X-ray binaries, recycled radio pulsars, double degenerate systems, and blue stragglers. Our work is based on a new parallel supercomputer code implementing Henon's Monte Carlo method for simulating the dynamical evolution of dense stellar systems in the Fokker-Planck approximation. This new code allows us to calculate very accurately the evolution of a cluster containing a realistic number of stars (N ~ 10^5 - 10^6) in typically a few hours to a few days of computing time. The discrete, s...

  3. Marangoni Convection in Binary Mixtures

    CERN Document Server

    Zhang, J; Oron, A; Behringer, Robert P.; Oron, Alexander; Zhang, Jie

    2006-01-01

    Marangoni instabilities in binary mixtures are different from those in pure liquids. In contrast to a large amount of experimental work on Marangoni convection in pure liquids, such experiments in binary mixtures are not available in the literature, to our knowledge. Using binary mixtures of sodium chloride/water, we have systematically investigated the pattern formation for a set of substrate temperatures and solute concentrations in an open system. The flow patterns evolve with time, driven by surface-tension fluctuations due to evaporation and the Soret effect, while the air-liquid interface does not deform. A shadowgraph method is used to follow the pattern formation in time. The patterns are mainly composed of polygons and rolls. The mean pattern size first decreases slightly, and then gradually increases during the evolution. Evaporation affects the pattern formation mainly at the early stage and the local evaporation rate tends to become spatially uniform at the film surface. The Soret effect becomes i...

  4. Asymmetric distances for binary embeddings.

    Science.gov (United States)

    Gordo, Albert; Perronnin, Florent; Gong, Yunchao; Lazebnik, Svetlana

    2014-01-01

    In large-scale query-by-example retrieval, embedding image signatures in a binary space offers two benefits: data compression and search efficiency. While most embedding algorithms binarize both query and database signatures, it has been noted that this is not strictly a requirement. Indeed, asymmetric schemes that binarize the database signatures but not the query still enjoy the same two benefits but may provide superior accuracy. In this work, we propose two general asymmetric distances that are applicable to a wide variety of embedding techniques including locality sensitive hashing (LSH), locality sensitive binary codes (LSBC), spectral hashing (SH), PCA embedding (PCAE), PCAE with random rotations (PCAE-RR), and PCAE with iterative quantization (PCAE-ITQ). We experiment on four public benchmarks containing up to 1M images and show that the proposed asymmetric distances consistently lead to large improvements over the symmetric Hamming distance for all binary embedding techniques.

  5. Black Hole Binaries in Quiescence

    CERN Document Server

    Bailyn, Charles D

    2016-01-01

    I discuss some of what is known and unknown about the behavior of black hole binary systems in the quiescent accretion state. Quiescence is important for several reasons: 1) the dominance of the companion star in the optical and IR wavelengths allows the binary parameters to be robustly determined - as an example, we argue that the longer proposed distance to the X-ray source GRO J1655-40 is correct; 2) quiescence represents the limiting case of an extremely low accretion rate, in which both accretion and jets can be observed; 3) understanding the evolution and duration of the quiescent state is a key factor in determining the overall demographics of X-rary binaries, which has taken on a new importance in the era of gravitational wave astronomy.

  6. Statistical Study of Visual Binaries

    CERN Document Server

    Abdel-Rahman, H I; Elsanhoury, W H

    2016-01-01

    In this paper, some statistical distributions of wide pairs included in Double Star Catalogue are investigated. Frequency distributions and testing hypothesis are derived for some basic parameters of visual binaries. The results reached indicate that, it was found that the magnitude difference is distributed exponentially, which means that the majority of the component of the selected systems is of the same spectral type. The distribution of the mass ratios is concentrated about 0.7 which agree with Salpeter mass function. The distribution of the linear separation appears to be exponentially, which contradict with previous studies for close binaries.

  7. Coalescing binaries and Doppler experiments

    OpenAIRE

    Vecchio, A.; Bertotti, B.; Iess, L.

    1997-01-01

    We discuss the sensitivity of the CASSINI experiments to gravitational waves emitted by the in-spiral of compact binaries. We show that the maximum distance reachable by the instrument is $\\sim 100$ Mpc. In particular, CASSINI can detect massive black hole binaries with chirp mass $\\simgt 10^6 \\Ms$ in the Virgo Cluster with signal-to-noise ratio between 5 and 30 and possible compact objects of mass $\\simgt 30 \\Ms$ orbiting the massive black hole that our Galactic Centre is likely to harbour.

  8. Study on the problems to BX1-200-3 arc welding transformers%BX1-200-3型弧焊变压器使用中存在的问题

    Institute of Scientific and Technical Information of China (English)

    李明利; 胡静

    2011-01-01

    根据某职业学校使用BX1-200-3型孤焊变压器对学生进行焊接实际操作培训时焊机接连出现损坏的现象,对该弧焊变压器的电气组成和原理进行了分析说明,指出了该弧焊变压器在电路结构和控制方法上存在的隐患及造成焊机损坏的原因,即两公共电源接线端子所接电源种类必须与焊机转换开关的档位保持严格对应关系,否则实际操作时稍有差错,即会造成风扇电机因过压而击穿或因欠压而烧毁,进而短时间内引起弧焊变压器线圈冒烟起火,焊机彻底损坏.对焊机生产厂家改进该种弧焊电源电气结构和控制方法具有一定的参考作用,对至今仍在使用该种型号弧焊变压器的用户具有一定的参考价值.%According to the phenomenon of continuous damage of BX1-200-3-type arc welding transformers when students of a vocational school in Beijing taking hands-on training courses,the paper describes the electrical component and the principles of the welding transformer, pointing out that there are risks about the arc transformer in the circuit structure and control methods.That is, the switch behind the welding transformers should maintain strict correspondence with the power type of the two public power terminals connected,otherwise once a slight mistake occurs in the actual operation,it will be very likely to lead to the situation that the fan motor breakdowns due to high voltage or burns due to low voltage, the are welding transformer coil smokes and gets fired after a short time,and at last the welding machine is damaged completely. The paper can be used as a reference by the welding machine manufacturers to improve the electric structure and the control method of welding machine of this type,and can still be used as a reminder and emphasis for users who are now using this type of arc welding transformer.

  9. Kepler Eclipsing Binaries with Stellar Companions

    CERN Document Server

    Gies, D R; Guo, Z; Lester, K V; Orosz, J A; Peters, G J

    2015-01-01

    Many short-period binary stars have distant orbiting companions that have played a role in driving the binary components into close separation. Indirect detection of a tertiary star is possible by measuring apparent changes in eclipse times of eclipsing binaries as the binary orbits the common center of mass. Here we present an analysis of the eclipse timings of 41 eclipsing binaries observed throughout the NASA Kepler mission of long duration and precise photometry. This subset of binaries is characterized by relatively deep and frequent eclipses of both stellar components. We present preliminary orbital elements for seven probable triple stars among this sample, and we discuss apparent period changes in seven additional eclipsing binaries that may be related to motion about a tertiary in a long period orbit. The results will be used in ongoing investigations of the spectra and light curves of these binaries for further evidence of the presence of third stars.

  10. Hydrodynamic Simulations of Contact Binaries

    Science.gov (United States)

    Kadam, Kundan; Clayton, Geoffrey C.; Frank, Juhan; Marcello, Dominic; Motl, Patrick M.; Staff, Jan E.

    2015-01-01

    The motivation for our project is the peculiar case of the 'red nova" V1309 Sco which erupted in September 2008. The progenitor was, in fact, a contact binary system. We are developing a simulation of contact binaries, so that their formation, structural, and merger properties could be studied using hydrodynamics codes. The observed transient event was the disruption of the secondary star by the primary, and their subsequent merger into one star; hence to replicate this behavior, we need a core-envelope structure for both the stars. We achieve this using a combination of Self Consistant Field (SCF) technique and composite polytropes, also known as bipolytropes. So far we have been able to generate close binaries with various mass ratios. Another consequence of using bipolytropes is that according to theoretical calculations, the radius of a star should expand when the core mass fraction exceeds a critical value, resulting in interesting consequences in a binary system. We present some initial results of these simulations.

  11. Discs in misaligned binary systems

    Science.gov (United States)

    Rawiraswattana, Krisada; Hubber, David A.; Goodwin, Simon P.

    2016-08-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-alignment processes, which tend to misalign the components. The alignment process dominates in systems with misalignment angle near 90°, while the anti-alignment process dominates in systems with the misalignment angle near 0° or 180°. This means that highly misaligned systems will become more aligned but slightly misaligned systems will become more misaligned.

  12. The Meritfactor of Binary Seqences

    DEFF Research Database (Denmark)

    Høholdt, Tom

    1999-01-01

    Binary sequences with small aperiodic correlations play an important role in many applications ranging from radar to modulation and testing of systems. Golay(1977) introduced the merit factor as a measure of the goodness of the sequence and conjectured an upper bound for this. His conjecture is s...

  13. CHAOTIC ZONES AROUND GRAVITATING BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Shevchenko, Ivan I., E-mail: iis@gao.spb.ru [Pulkovo Observatory of the Russian Academy of Sciences, Pulkovskoje ave. 65, St. Petersburg 196140 (Russian Federation)

    2015-01-20

    The extent of the continuous zone of chaotic orbits of a small-mass tertiary around a system of two gravitationally bound primaries of comparable masses (a binary star, a binary black hole, a binary asteroid, etc.) is estimated analytically, as a function of the tertiary's orbital eccentricity. The separatrix map theory is used to demonstrate that the central continuous chaos zone emerges (above a threshold in the primaries' mass ratio) due to overlapping of the orbital resonances corresponding to the integer ratios p:1 between the tertiary and the central binary periods. In this zone, the unlimited chaotic orbital diffusion of the tertiary takes place, up to its ejection from the system. The primaries' mass ratio, above which such a chaotic zone is universally present at all initial eccentricities of the tertiary, is estimated. The diversity of the observed orbital configurations of biplanetary and circumbinary exosystems is shown to be in accord with the existence of the primaries' mass parameter threshold.

  14. A Galactic Binary Detection Pipeline

    Science.gov (United States)

    Littenberg, Tyson B.

    2011-01-01

    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 2:: 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.

  15. A Redundant Binary Algorithm for RSA

    Institute of Scientific and Technical Information of China (English)

    施荣华

    1996-01-01

    The normal form and modified normal form for binary redundant representation are defined.A redundant binary algorithm to compute modular exponentiation for very large integers is proposed.It is shown that the proposed algorithm requires the minimum number of basic operations(modular multiplications)among all possible binary redundant representations.

  16. Division Unit for Binary Integer Decimals

    DEFF Research Database (Denmark)

    Lang, Tomas; Nannarelli, Alberto

    2009-01-01

    In this work, we present a radix-10 division unit that is based on the digit-recurrence algorithm and implements binary encodings (binary integer decimal or BID) for significands. Recent decimal division designs are all based on the binary coded decimal (BCD) encoding. We adapt the radix-10 digit...

  17. Numerical Evaluation of Mode 1 Stress Intensity Factor as a Function of Material Orientation For BX-265 Foam Insulation Material

    Science.gov (United States)

    Knudsen, Erik; Arakere, Nagaraj K.

    2006-01-01

    Foam; a cellular material, is found all around us. Bone and cork are examples of biological cell materials. Many forms of man-made foam have found practical applications as insulating materials. NASA uses the BX-265 foam insulation material on the external tank (ET) for the Space Shuttle. This is a type of Spray-on Foam Insulation (SOFI), similar to the material used to insulate attics in residential construction. This foam material is a good insulator and is very lightweight, making it suitable for space applications. Breakup of segments of this foam insulation on the shuttle ET impacting the shuttle thermal protection tiles during liftoff is believed to have caused the space shuttle Columbia failure during re-entry. NASA engineers are very interested in understanding the processes that govern the breakup/fracture of this complex material from the shuttle ET. The foam is anisotropic in nature and the required stress and fracture mechanics analysis must include the effects of the direction dependence on material properties. Material testing at NASA MSFC has indicated that the foam can be modeled as a transversely isotropic material. As a first step toward understanding the fracture mechanics of this material, we present a general theoretical and numerical framework for computing stress intensity factors (SIFs), under mixed-mode loading conditions, taking into account the material anisotropy. We present mode I SIFs for middle tension - M(T) - test specimens, using 3D finite element stress analysis (ANSYS) and FRANC3D fracture analysis software, developed by the Cornel1 Fracture Group. Mode I SIF values are presented for a range of foam material orientations. Also, NASA has recorded the failure load for various M(T) specimens. For a linear analysis, the mode I SIF will scale with the far-field load. This allows us to numerically estimate the mode I fracture toughness for this material. The results represent a quantitative basis for evaluating the strength and

  18. A Multi-Wavelength Study of the 3B/X1.2 Flare Observed on 2003 October 26

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Jian-Ping Li; Cheng Fang; Brigitte Schmieder; Arkadiusz Berlicki; Qiu-Sheng Du

    2005-01-01

    We report results from a multi-wavelength study of the 3B/X1.2 tworibbon disk flare (S15E44), which was well observed by both ground-based and space-borne instruments. Two pairs of conjugate kernels - K1 and K4, and K2and K3 - in the Hα images are identified. These kernels are linked by two different systems of EUV loops. K1 and K4 correspond to the two 17 GHz and 34 GHz microwave sources observed by the Nobeyama Radioheliograph (NoRH), while K2and K3 have no corresponding microwave sources. Optical spectroscopic observations suggest that all the four kernels are possible precipitating sites of non-thermal electrons. Thus the energy of electron deposited in K2 and K3 should be less than 100 keV. Two-dimensional distributions of the full widths at half maximum (FWHM) of the Hα profiles and the line-of-sight (LOS) velocities derived from the Ca Ⅱ 8542 (A) profiles indicate that the largest FWHM and LOS velocity tends to be located near the outer edges of Hα kernels, which is consistent with the scenario of current two-ribbon flare models and previous results. When non-thermal electron bombardment is present, the observed Hα and Ca Ⅱ 8542 A profiles are similar to previous observational and theoretical results, while the He Ⅰ 10830 (A) profiles are different from the theoretical ones. This puts some constraints on future theoretical calculation of the He Ⅰ 10830 (A) line.

  19. Focalyx Dx, Bx, Tx et Apps: A novel contemporary fusion paradigm for the management of prostate cancer.

    Science.gov (United States)

    Bianco, F J; Martínez-Salamanca, J I

    2016-07-01

    FocalyxTM conceived as a response to emerging evidence data across numerous cancer lesions that questions current standard treatment approaches that too often lead to detrimental quality of life yet delivering limited survival benefit, especially in-lieu of advances in imaging technology applicable to cancer patients. The Focalyx paradigm aims to control cancer with improvement in quality of life. We initially devised 5 milestones: 1- Consistently optimize Prostate MRI imaging using the novel published protocols adopted as guidelines by societies such as the European Society of Urology and Radiology; 2- Evaluate fusion platform software solutions that existed; 3- Determine best fusión platform for Focalyx on practicality, precision, and workflow premises; 4- Evaluate commercially available FDA approved ablative technologies to implement our treatment vision; 5- Design a treatment option that can be performed in the office setting under local anesthesia, which would not impact negatively QOL outcomes of Prostate Cancer patients and seamless constant nonintrusive practical patient-physician interaction by the Focalyx app that facilitates follow up and provides early warning signals shall any change in the disease dynamics emerge. Prostate cancer was identified as the pilot disease for Focalyx to deliver a "GPS" like solution for the prostate gland that destroys identifiable disease without adverse effects such as: cancer anxiety, urinary incontinence, loss of erections and ejaculation. Since September of 2013, over 300 men have been accrued in NCT02381990- clintrials.gov evaluating the feasibility of our solutions for imaging (FocalyxDx), Biopsy (FocalyxBx) and Treatment (FocalyxTx). In this review we detail the tools available to achieve the Focalyx paradigm for men with Prostate Cancer. PMID:27416639

  20. Focalyx Dx, Bx, Tx et Apps: A novel contemporary fusion paradigm for the management of prostate cancer.

    Science.gov (United States)

    Bianco, F J; Martínez-Salamanca, J I

    2016-07-01

    FocalyxTM conceived as a response to emerging evidence data across numerous cancer lesions that questions current standard treatment approaches that too often lead to detrimental quality of life yet delivering limited survival benefit, especially in-lieu of advances in imaging technology applicable to cancer patients. The Focalyx paradigm aims to control cancer with improvement in quality of life. We initially devised 5 milestones: 1- Consistently optimize Prostate MRI imaging using the novel published protocols adopted as guidelines by societies such as the European Society of Urology and Radiology; 2- Evaluate fusion platform software solutions that existed; 3- Determine best fusión platform for Focalyx on practicality, precision, and workflow premises; 4- Evaluate commercially available FDA approved ablative technologies to implement our treatment vision; 5- Design a treatment option that can be performed in the office setting under local anesthesia, which would not impact negatively QOL outcomes of Prostate Cancer patients and seamless constant nonintrusive practical patient-physician interaction by the Focalyx app that facilitates follow up and provides early warning signals shall any change in the disease dynamics emerge. Prostate cancer was identified as the pilot disease for Focalyx to deliver a "GPS" like solution for the prostate gland that destroys identifiable disease without adverse effects such as: cancer anxiety, urinary incontinence, loss of erections and ejaculation. Since September of 2013, over 300 men have been accrued in NCT02381990- clintrials.gov evaluating the feasibility of our solutions for imaging (FocalyxDx), Biopsy (FocalyxBx) and Treatment (FocalyxTx). In this review we detail the tools available to achieve the Focalyx paradigm for men with Prostate Cancer.

  1. Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Oostrom, Martinus; Carroll, KC; Chronister, Glen B.

    2013-06-28

    Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

  2. SURFACE GEOPHYSICAL EXPLORATION OF B & BX & BY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA

    2007-09-28

    This report documents the results of preliminary surface geophysical exploration activities performed between October and December 2006 at the B, BX, and BY tank farms (B Complex). The B Complex is located in the 200 East Area of the U. S. Department of Energy's Hanford Site in Washington State. The objective of the preliminary investigation was to collect background characterization information with magnetic gradiometry and electromagnetic induction to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity survey. Results of the background characterization show there are several areas located around the site with large metallic subsurface debris or metallic infrastructure.

  3. Permutation Entropy for Random Binary Sequences

    Directory of Open Access Journals (Sweden)

    Lingfeng Liu

    2015-12-01

    Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

  4. In vitro effect of erlotinib on the growth of pancreatic cancer cell line BxPC3 and its mechanism%埃罗替尼对胰腺癌细胞BxPC3生长的影响及其机制

    Institute of Scientific and Technical Information of China (English)

    陆颖影; 靖大道; 王兴鹏; 吴恺

    2009-01-01

    Objective To investigate the effect and possible mechanism of erlotinib,an epidermal growth factor recceptor inhibitor,on human pancreatic cancer cell lines BxPC3 in vitro.Methods Methyhhiazolyhetrazolium(MTT)assay was used to detected the proliferation of BxPC3 after exposure to erlotinib,apoptosis and cell cycle changes were studied by flow eytometry and terminal deoxynucleotidyl transferase-mediated nick end labeling assay(TUNEL).The expressions of bcl-2 mRNA,bax mRNA,bcl-xL mRNA and bak mRNA were determined by reverse transcriptase polymerase chain reaction(RT-PCR). Results Edotinib inhibited BxPC3 cells growth in a dose and time dependent manner in vitro.The cell viabilities in erlotinib 1 μmol/L and 100 μmol/L groups 72 h later were(90.25 ±2.62)%and(40.75 ±2.98)%,and the difference was statistically significant(P<0.01).The cell viability in edotinib 50 μmol/L groups 24 h and 96 h after BxPC3 exposure were(74.0±4.08)%and(49.50 ±1.29)%,and the difference was statistically significant(P<0.01).Cell apoptosis rate in erlotinib 50 μmol/L group was(11.0 μ1.1)%,which was significantly higher than(6.2 ±1.1)%in control group(P<0.01).G_0/G_1 cell accounted for (73.4±1.3)%of all the cells,which was significantly higher than(63.3 ±1.O)%in control group.With transmission electron microscope,the morphology of BxPC3 ceils showed typical apoptosis and apoptotic body. The expressions of bcl-2 mRNA,bel-xl mRNA were down-regulated,while the expression of bax mRNA was slightly up-regulated,and the expression of bak mRNA was not affected.Conclusions The growth of BxPC3 cells could be suppressed by erlotinib and possible mechanisms involved blocking cell cycle,up-regulating apoptosis proteins and down-regulating apoptosis inhibitor proteins.%目的 观察表皮生长因子受体(EGFR)抑制剂埃罗替尼对体外培养的胰腺痛细胞BxPC3生长的影响,并探讨其作用机制.方法 应用MTT法检测埃罗替尼作用后BxPC3细胞的增殖情况;用流式细胞

  5. Desktop setup for binary holograms

    Science.gov (United States)

    Ginter, Olaf; Rothe, Hendrik

    1996-08-01

    Binary gratings as holograms itself or as photographic masking tools for further fabrication steps can fulfill a lot of applications. The commonly used semiconductor technologies for direct writing of high resolution structures are often too expensive. On the other hand computer plots at a reasonable price with photographic reduction do not meet the needs of precision e.g. for interferometric inspection. The lack of cheap and reliable instruments for direct writing in an appropriate resolution is still a problem in fabricating synthetic holograms. Using off-the-shelf components a direct writing plotter for binary patterns can be built at moderate costs. Typical design rules as well as experimental results are given and the final setup is introduced.

  6. Close supermassive binary black holes

    Science.gov (United States)

    Gaskell, C. Martin

    2010-01-01

    It has been proposed that when the peaks of the broad emission lines in active galactic nuclei (AGNs) are significantly blueshifted or redshifted from the systemic velocity of the host galaxy, this could be a consequence of orbital motion of a supermassive blackhole binary (SMB). The AGN J1536+0441 (=SDSS J153636.22+044127.0) has recently been proposed as an example of this phenomenon. It is proposed here instead that 1536+044 is an example of line emission from a disc. If this is correct, the lack of clear optical spectral evidence for close SMBs is significant and argues either that the merging of close SMBs is much faster than has generally been hitherto thought, or if the approach is slow, that when the separation of the binary is comparable to the size of the torus and broad-line region, the feeding of the black holes is disrupted.

  7. Event Rates for Binary Inspiral

    CERN Document Server

    Kalogera, V

    2001-01-01

    Double compact objects (neutron stars and black holes) found in binaries with small orbital separations are known to spiral in and are expected to coalesce eventually because of the emission of gravitational waves. Such inspiral and merger events are thought to be primary sources for ground based gravitational-wave interferometric detectors (such as LIGO). Here, we present a brief review of estimates of coalescence rates and we examine the origin and relative importance of uncertainties associated with the rate estimates. For the case of double neutron star systems, we compare the most recent rate estimates to upper limits derived in a number of different ways. We also discuss the implications of the formation of close binaries with two non-recycled pulsars.

  8. Remnants of compact binary mergers

    CERN Document Server

    Domainko, W

    2006-01-01

    We investigate the long-term evolution and observability of remnants originating from the merger of compact binary systems and discuss the differences to supernova remnants. Compact binary mergers expel much smaller amounts of mass at much higher velocities, as compared to supernovae, which will affect the dynamical evolution of their remnants. The ejecta of mergers consist of very neutron rich nuclei. Some of these neutron rich nuclei will produce observational signatures in form of gamma ray lines during their decay. The composition of the ejecta might even give interesting constraints about the internal structure of the neutron star. We further discuss the possibility that merger remnants appear as recently discovered 'dark accelerators' which are extended TeV sources which lack emission in other bands.

  9. Modified binary particle swam optimization

    Institute of Scientific and Technical Information of China (English)

    Sangwook Lee; Sangmoon Soak; Sanghoun Oh; Witold Pedrycz; Moongu Jeon

    2008-01-01

    This paper presents a modified binary particle swarm optimization(BPSO)which adopts concepts of the genotype-phenotype rep-resentation and the mutation operator of genetic algorithms.Its main feature is that the BPSO can be treated as a continuous PSO.The proposed BPSO algorithm is tested on various benchmark functions,and its performance is compared with that of the original BPSO.Experimental results show that the modified BPSO outperforms the original BPSO algorithm.

  10. Tides in asynchronous binary systems

    OpenAIRE

    Toledano, Oswaldo; Moreno, Edmundo; Koenigsberger, Gloria; Detmers, R.; Langer, Norbert

    2006-01-01

    Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a stratified outer medium. In this paper we show that our single-layer approximation for the calculation of the forced oscillations yields results that are consistent with the predictions for the synchronization timescales in circular orbits. In addition, calibrat...

  11. Structure, variation and expression analysis of glutenin gene promoters from Triticum aestivum cultivar Chinese Spring shows the distal region of promoter 1Bx7 is key regulatory sequence.

    Science.gov (United States)

    Wang, Kai; Zhang, Xue; Zhao, Ying; Chen, Fanguo; Xia, Guangmin

    2013-09-25

    In this study, ten glutenin gene promoters were isolated from model wheat (Triticum aestivum L. cv. Chinese Spring) using a genomic PCR strategy with gene-specific primers. Six belonged to high-molecular-weight glutenin subunit (HMW-GS) gene promoters, and four to low-molecular-weight glutenin subunit (LMW-GS). Sequence lengths varied from 1361 to 2,554 bp. We show that the glutenin gene promoter motifs are conserved in diverse sequences in this study, with HMW-GS and LMW-GS gene promoters characterized by distinct conserved motif combinations. Our findings show that HMW-GS promoters contain more functional motifs in the distal region of the glutenin gene promoter (> -700 bp) compared with LMW-GS. The y-type HMW-GS gene promoters possess unique motifs including RY repeat and as-2 box compared to the x-type. We also identified important motifs in the distal region of HMW-GS gene promoters including the 5'-UTR Py-rich stretch motif and the as-2 box motif. We found that cis-acting elements in the distal region of promoter 1Bx7 enhanced the expression of HMW-GS gene 1Bx7. Taken together, these data support efforts in designing molecular breeding strategies aiming to improve wheat quality. Our results offer insight into the regulatory mechanisms of glutenin gene expression.

  12. High hardness BaCb-(BxOy/BN) composites with 3D mesh-like fine grain-boundary structure by reactive spark plasma sintering.

    Science.gov (United States)

    Vasylkiv, Oleg; Borodianska, Hanna; Badica, Petre; Grasso, Salvatore; Sakka, Yoshio; Tok, Alfred; Su, Liap Tat; Bosman, Michael; Ma, Jan

    2012-02-01

    Boron carbide B4C powders were subject to reactive spark plasma sintering (also known as field assisted sintering, pulsed current sintering or plasma assisted sintering) under nitrogen atmosphere. For an optimum hexagonal BN (h-BN) content estimated from X-ray diffraction measurements at approximately 0.4 wt%, the as-prepared BaCb-(BxOy/BN) ceramic shows values of Berkovich and Vickers hardness of 56.7 +/- 3.1 GPa and 39.3 +/- 7.6 GPa, respectively. These values are higher than for the vacuum SPS processed B4C pristine sample and the h-BN -mechanically-added samples. XRD and electronic microscopy data suggest that in the samples produced by reactive SPS in N2 atmosphere, and containing an estimated amount of 0.3-1.5% h-BN, the crystallite size of the boron carbide grains is decreasing with the increasing amount of N2, while for the newly formed lamellar h-BN the crystallite size is almost constant (approximately 30-50 nm). BN is located at the grain boundaries between the boron carbide grains and it is wrapped and intercalated by a thin layer of boron oxide. BxOy/BN forms a fine and continuous 3D mesh-like structure that is a possible reason for good mechanical properties.

  13. Temperature affecting the magnetic properties of the Co79−xFe3Cr3Si15Bx amorphous alloy

    International Nuclear Information System (INIS)

    The paper studies the effect the temperature has on the magnetic properties of the Co79−xFe3Cr3Si15Bx amorphous alloy with different boron content. Magnetic saturation induction Bs and Curie temperature TC decrease as the boron content increases. Within the range of relatively high temperatures, magnetic saturation induction Bs = μ0Ms is related to the temperature by Bs(T) ∼ (TC − T)0.38. In the Co79−xFe3Cr3Si15Bx amorphous alloys with the Curie temperature of lower than 180 °C the initial permeability of 200,000 and the coercive force of 0.1 A/m were obtained. The high initial permeability of the amorphous alloy is attributed to the absence of the crystalline, magnetoelastic and induced magnetic anisotropy in this alloy. Low Curie temperature near which the permeability appreciably increases (Hopkinson effect) is another approach to the ideal magnetic softness

  14. Borehole Data Package for Well 299-E33-44 at Single-Shell Tank Waste Management Area B-BX-BY

    Energy Technology Data Exchange (ETDEWEB)

    DG Horton; SM Narbutovskih

    1999-03-23

    One new Resource Conservation and Recovery Act (RCRA) groundwater monitoring well was installed during September 1998 at the single-shell tank farm Waste Management Area (WMA) B-BX-BY. The well is 299-E33-44 and is located east of the BY single-shell tank farm. The well is a new upgradient monitoring well drilled in support of the groundwater assessment program at WMA B-BX-BY. This document is a compilation of information on the drilling and construction well development pump installation, and sediment testing and analyses applicable to well 299-E33-44. Appendix A contains copies of the geologist's log, the Well Construction Summary Report and Well Summary Sheet (as-built diagram); Appendix B contains results of Laboratory analyses completed on samples of sediment from the well and Appendix C contains geophysical logs. An aquifer test (slug test) was done in the well after well completion. Results from the aquifer test will be published elsewhere. Additional documentation concerning well construction is on file with Bechtel Hanford Inc., Richland, Washington.

  15. Evolution of binary stars in multiple-population globular clusters - II. Compact binaries

    Science.gov (United States)

    Hong, Jongsuk; Vesperini, Enrico; Sollima, Antonio; McMillan, Stephen L. W.; D'Antona, Franca; D'Ercole, Annibale

    2016-04-01

    We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters. We show that as a consequence of the initial differences in the structural properties of the first-generation (FG) and the second-generation (SG) populations and the effects of dynamical processes on binary stars, the SG binary fraction decreases more rapidly than that of the FG population. The difference between the FG and SG binary fraction is qualitatively similar to but quantitatively smaller than that found for wider binaries in our previous investigations. The evolution of the radial variation of the binary fraction is driven by the interplay between binary segregation, ionization and ejection. Ionization and ejection counteract in part the effects of mass segregation but for compact binaries the effects of segregation dominate and the inner binary fraction increases during the cluster evolution. We explore the variation of the difference between the FG and the SG binary fraction with the distance from the cluster centre and its dependence on the binary binding energy and cluster structural parameters. The difference between the binary fraction in the FG and the SG populations found in our simulations is consistent with the results of observational studies finding a smaller binary fraction in the SG population.

  16. Detection of unresolved binaries with multicolor photometry

    CERN Document Server

    Chulkov, D; Malkov, O; Sichevskij, S; Krussanova, N; Mironov, A; Zakharov, A; Kniazev, A

    2016-01-01

    The principal goal of this paper is to specify conditions of detection of unresolved binaries by multicolor photometry. We have developed a method for estimating the critical distance at which an unresolved binary of given mass and age can be detected. The method is applied to the photometric system of the planned Lyra-B spaceborne experiment. We have shown that some types of unresolved binary stars can be discovered and distinguished from single stars solely by means of photometric observations.

  17. Asteroid Systems: Binaries, Triples, and Pairs

    CERN Document Server

    Margot, Jean-Luc; Taylor, Patrick; Carry, Benoît; Jacobson, Seth

    2015-01-01

    In the past decade, the number of known binary near-Earth asteroids has more than quadrupled and the number of known large main belt asteroids with satellites has doubled. Half a dozen triple asteroids have been discovered, and the previously unrecognized populations of asteroid pairs and small main belt binaries have been identified. The current observational evidence confirms that small (20 km) binaries with small satellites are most likely created during large collisions.

  18. Orbital eccentricities in primordial black holes binaries

    OpenAIRE

    Cholis, Ilias; Kovetz, Ely D.; Ali-Haïmoud, Yacine; Bird, Simeon; Kamionkowski, Marc; Muñoz, Julian B.; Raccanelli, Alvise

    2016-01-01

    It was recently suggested that the merger of $\\sim30\\,M_\\odot$ primordial black holes (PBHs) may provide a significant number of events in gravitational-wave observatories over the next decade, if they make up an appreciable fraction of the dark matter. Here we show that measurement of the eccentricities of the inspiralling binary black holes can be used to distinguish these binaries from those produced by more traditional astrophysical mechanisms. These PBH binaries are formed on highly ecce...

  19. Microlensing Signature of Binary Black Holes

    Science.gov (United States)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  20. Detecting Near-Extremal Binary Black Holes

    Science.gov (United States)

    Hemberger, Daniel

    2014-03-01

    There is an ongoing effort in the gravitational wave astronomy community to construct a template bank for Advanced LIGO that includes gravitational waveforms from binary black hole systems with high mass ratios and spins. Using numerical relativity simulations performed with the Spectral Einstein Code, we assess the prospects for detection and parameter estimation of binaries with spins above the expected template bank cutoff spin. This analysis is restricted to equal-mass, non-precessing binaries.

  1. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    We evaluate the binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Harrison, Martínez-Correa and Swarthout [2013] found that the binary lottery procedure works robustly to induce risk neutrality when subjects are given one risk task defined over...... objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...

  2. Speech perception of noise with binary gains

    DEFF Research Database (Denmark)

    Wang, DeLiang; Kjems, Ulrik; Pedersen, Michael Syskind;

    2008-01-01

    For a given mixture of speech and noise, an ideal binary time-frequency mask is constructed by comparing speech energy and noise energy within local time-frequency units. It is observed that listeners achieve nearly perfect speech recognition from gated noise with binary gains prescribed by the i...... by the ideal binary mask. Only 16 filter channels and a frame rate of 100 Hz are sufficient for high intelligibility. The results show that, despite a dramatic reduction of speech information, a pattern of binary gains provides an adequate basis for speech perception....

  3. Massive Stars in Interactive Binaries

    Science.gov (United States)

    St.-Louis, Nicole; Moffat, Anthony F. J.

    Massive stars start their lives above a mass of ~8 time solar, finally exploding after a few million years as core-collapse or pair-production supernovae. Above ~15 solar masses, they also spend most of their lives driving especially strong, hot winds due to their extreme luminosities. All of these aspects dominate the ecology of the Universe, from element enrichment to stirring up and ionizing the interstellar medium. But when they occur in close pairs or groups separated by less than a parsec, the interaction of massive stars can lead to various exotic phenomena which would not be seen if there were no binaries. These depend on the actual separation, and going from wie to close including colliding winds (with non-thermal radio emission and Wolf-Rayet dust spirals), cluster dynamics, X-ray binaries, Roche-lobe overflow (with inverse mass-ratios and rapid spin up), collisions, merging, rejuventation and massive blue stragglers, black-hole formation, runaways and gamma-ray bursts. Also, one wonders whether the fact that a massive star is in a binary affects its parameters compared to its isolated equivalent. These proceedings deal with all of these phenomena, plus binary statistics and determination of general physical properties of massive stars, that would not be possible with their single cousins. The 77 articles published in these proceedings, all based on oral talks, vary from broad revies to the lates developments in the field. About a third of the time was spent in open discussion of all participants, both for ~5 minutes after each talk and 8 half-hour long general dialogues, all audio-recorded, transcribed and only moderately edited to yield a real flavour of the meeting. The candid information in these discussions is sometimes more revealing than the article(s) that preceded them and also provide entertaining reading. The book is suitable for researchers and graduate students interested in stellar astrophysics and in various physical processes involved when

  4. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  5. Young and Waltzing Binary Stars

    Science.gov (United States)

    2001-10-01

    ADONIS Observes Low-mass Eclipsing System in Orion Summary A series of very detailed images of a binary system of two young stars have been combined into a movie . In merely 3 days, the stars swing around each other. As seen from the earth, they pass in front of each other twice during a full revolution, producing eclipses during which their combined brightness diminishes . A careful analysis of the orbital motions has now made it possible to deduce the masses of the two dancing stars . Both turn out to be about as heavy as our Sun. But while the Sun is about 4500 million years old, these two stars are still in their infancy. They are located some 1500 light-years away in the Orion star-forming region and they probably formed just 10 million years ago . This is the first time such an accurate determination of the stellar masses could be achieved for a young binary system of low-mass stars . The new result provides an important piece of information for our current understanding of how young stars evolve. The observations were obtained by a team of astronomers from Italy and ESO [1] using the ADaptive Optics Near Infrared System (ADONIS) on the 3.6-m telescope at the ESO La Silla Observatory. PR Photo 29a/01 : The RXJ 0529.4+0041 system before primary eclipse PR Photo 29b/01 : The RXJ 0529.4+0041 system at mid-primary eclipse PR Photo 29c/01 : The RXJ 0529.4+0041 system after primary eclipse PR Photo 29d/01 : The RXJ 0529.4+0041 system before secondary eclipse PR Photo 29e/01 : The RXJ 0529.4+0041 system at mid-secondary eclipse PR Photo 29f/01 : The RXJ 0529.4+0041 system after secondary eclipse PR Video Clip 06/01 : Video of the RXJ 0529.4+0041 system Binary stars and stellar masses Since some time, astronomers have noted that most stars seem to form in binary or multiple systems. This is quite fortunate, as the study of binary stars is the only way in which it is possible to measure directly one of the most fundamental quantities of a star, its mass. The mass of a

  6. R144 : a very massive binary likely ejected from R136 through a binary-binary encounter

    CERN Document Server

    Oh, Seungkyung; Banerjee, Sambaran

    2013-01-01

    R144 is a recently confirmed very massive, spectroscopic binary which appears isolated from the core of the massive young star cluster R136. The dynamical ejection hypothesis as an origin for its location is claimed improbable by Sana et al. due to its binary nature and high mass. We demonstrate here by means of direct N-body calculations that a very massive binary system can be readily dynamically ejected from a R136-like cluster, through a close encounter with a very massive system. One out of four N-body cluster models produces a dynamically ejected very massive binary system with a mass comparable to R144. The system has a system mass of $\\approx$ 355 Msun and is located at 36.8 pc from the centre of its parent cluster, moving away from the cluster with a velocity of 57 km/s at 2 Myr as a result of a binary-binary interaction. This implies that R144 could have been ejected from R136 through a strong encounter with an other massive binary or single star. In addition, we discuss all massive binaries and sin...

  7. Millisecond Pulsars in Close Binaries

    CERN Document Server

    Tauris, Thomas M

    2015-01-01

    In this Habilitationsschrift (Habilitation thesis) I present my research carried out over the last four years at the Argelander Institute for Astronomy (AIfA) and the Max Planck Institute for Radio Astronomy (MPIfR). The thesis summarizes my main findings and has been written to fulfill the requirements for the Habilitation qualification at the University of Bonn. Although my work is mainly focused on the topic of millisecond pulsars (MSPs), there is a fairly broad spread of research areas ranging from the formation of neutron stars (NSs) in various supernova (SN) events, to their evolution, for example, via accretion processes in binary and triple systems, and finally to their possible destruction in merger events. The thesis is organized in the following manner: A general introduction to neutron stars and millisecond pulsars is given in Chapter 1. A selection of key papers published in 2011-2014 are presented in Chapters 2-10, ordered within five main research areas (ultra-stripped SNe in close binaries, ma...

  8. Close Binary System GO Cyg

    CERN Document Server

    Ulas, B; Keskin, V; Kose, O; Yakut, K

    2011-01-01

    In this study, we present long term photometric variations of the close binary system \\astrobj{GO Cyg}. Modelling of the system shows that the primary is filling Roche lobe and the secondary of the system is almost filling its Roche lobe. The physical parameters of the system are $M_1 = 3.0\\pm0.2 M_{\\odot}$, $M_2 = 1.3 \\pm 0.1 M_{\\odot}$, $R_1 = 2.50\\pm 0.12 R_{\\odot}$, $R_2 = 1.75 \\pm 0.09 R_{\\odot}$, $L_1 = 64\\pm 9 L_{\\odot}$, $L_2 = 4.9 \\pm 0.7 L_{\\odot}$, and $a = 5.5 \\pm 0.3 R_{\\odot}$. Our results show that \\astrobj{GO Cyg} is the most massive system near contact binary (NCB). Analysis of times of the minima shows a sinusoidal variation with a period of $92.3\\pm0.5$ years due to a third body whose mass is less than 2.3$M_{\\odot}$. Finally a period variation rate of $-1.4\\times10^{-9}$ d/yr has been determined using all available light curves.

  9. Interacting Jets from Binary Protostars

    CERN Document Server

    Murphy, G C; O'Sullivan, S; Spicer, D; Bacciotti, F; Rosén, A

    2007-01-01

    We investigate potential models that could explain why multiple proto-stellar systems predominantly show single jets. During their formation, stars most frequently produce energetic outflows and jets. However, binary jets have only been observed in a very small number of systems. We model numerically 3D binary jets for various outflow parameters. We also model the propagation of jets from a specific source, namely L1551 IRS 5, known to have two jets, using recent observations as constraints for simulations with a new MHD code. We examine their morphology and dynamics, and produce synthetic emission maps. We find that the two jets interfere up to the stage where one of them is almost destroyed or engulfed into the second one. We are able to reproduce some of the observational features of L1551 such as the bending of the secondary jet. While the effects of orbital motion are negligible over the jets dynamical timeline, their interaction has significant impact on their morphology. If the jets are not strictly pa...

  10. First-Principles Study of Electronic and Optical Properties of BxGa1 - xAs Alloy%BxGa1-xAs合金电子结构与光学性质的第一性原理计算

    Institute of Scientific and Technical Information of China (English)

    闫映策; 王彦龙; 马会芳

    2016-01-01

    First⁃principles calculations based on density functional theory are performed for zinc⁃blende BxGa1 - xAs alloy with a special quasirandom structure (SQS) approach in a 64⁃atom supercell. Structural, electronic and optical properties of BxGa1 - xAs alloy are comprehensively investigated under optimized geometry structures. It was found that calculated lattice constant slightly deviated from Vegards law and significant bond length relaxation is shown. Calculated bowing parameters of energy gap are small (2 57 eV - 5 01 eV) and are weakly composition⁃dependent. Finally, effects of boron composition on optical parameters including dielectric function, reflectivity, refractive index, absorption coefficient and energy loss function are analyzed in detail.%基于密度泛函理论的第一性原理和特殊准随机近似方法,建立64原子的超胞并且对结构进行几何优化.计算和讨论具有闪锌矿结构的三元合金 BxGa1- xAs 的结构参数、电子结构和光学性质.结果表明:BxGa1- xAs 的晶格常数与使用 Vegard 定理计算得到的值有微弱的偏离,键长存在明显的弛豫;计算得到的合金带隙弯曲参数变化较小(2.57 eV -5.01 eV)而且对组分变化的依赖很弱;最后分析硼的并入对 GaAs 光学参数包括介电函数、反射率、折射率、吸收系数和能量耗散函数的影响.

  11. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Yungelson, Lev R.

    2006-12-01

    Full Text Available We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs, neutron stars (NSs, and black holes (BHs. Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA. Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.

  12. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Konstantin A. Postnov

    2014-05-01

    Full Text Available 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-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH 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 the 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.

  13. Helium in atmospheres of binary stars

    Energy Technology Data Exchange (ETDEWEB)

    Leushin, V.V. (Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Fiziki)

    The helium abundances were obtained for 25 bright components of binary stars by model atmosphere analysis. The helium abundance for binary stars that lie on the main sequence are larger in the average than in single normal stars. The stars on the Hertzsppung - russel diagram lie at a larger distance from the zero age line than those with normal helium abundance.

  14. Bayesian analysis of exoplanet and binary orbits

    OpenAIRE

    Schulze-Hartung, Tim; Launhardt, Ralf; Henning, Thomas

    2012-01-01

    We introduce BASE (Bayesian astrometric and spectroscopic exoplanet detection and characterisation tool), a novel program for the combined or separate Bayesian analysis of astrometric and radial-velocity measurements of potential exoplanet hosts and binary stars. The capabilities of BASE are demonstrated using all publicly available data of the binary Mizar A.

  15. Binary Relations as a Foundation of Mathematics

    NARCIS (Netherlands)

    Kuper, J.; Barendsen, E.; Capretta, V.; Geuvers, H.; Niqui, M.

    2007-01-01

    We describe a theory for binary relations in the Zermelo-Fraenkel style. We choose for ZFCU, a variant of ZFC Set theory in which the Axiom of Foundation is replaced by an axiom allowing for non-wellfounded sets. The theory of binary relations is shown to be equi-consistent ZFCU by constructing a mo

  16. Coalescing binaries as possible standard candles

    OpenAIRE

    Capozziello, S.; De Laurentis, M.; Formisano, M.

    2009-01-01

    Gravitational waves detected from well-localized inspiraling binaries would allow to determine, directly and independently, both binary luminosity and redshift. In this case, such systems could behave as "standard candles" providing an excellent probe of cosmic distances up to $z

  17. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.;

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing ...

  18. Cosmological distance indicators by coalescing binaries

    CERN Document Server

    De Laurentis, Mariafelicia; De Martino, Ivan; Formisano, Michelangelo

    2011-01-01

    Gravitational waves detected from well-localized inspiraling binaries would allow to determine, directly and independently, both binary luminosity and redshift. In this case, such systems could behave as "standard candles" providing an excellent probe of cosmic distances up to z < 0.1 and thus complementing other indicators of cosmological distance ladder.

  19. First-Principles Calculations Of Electronic Structures of New Ⅲ-Ⅴ Semiconductors: BxGa1-x As and Tlx Ga1-x As alloys

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jing; REN Xiao-Min; HUANG Yong-Qing; WANG Qi; HUANG Hui

    2008-01-01

    We investigate the electronic structures of new semiconductor alloys BxGa1-x As and Tlx Ga1-x As, employing first-principles calculations within the density-functional theory and the generalized gradient approximation.The calculation results indicate that alloying a small Tl content with GaAs will produce larger modifications of the band structures compared to B. A careful investigation of the internal lattice structure relaxation shows that significant bond-length relaxations takes place in both the alloys, and it turns out that difference between the band-gap bowing behaviours for B and Tl stems from the different impact of atomic relaxation on the electronic structure. The relaxed structure yields electronic-structure results, which are in good agreement with the experimental data. Finally, a comparison of formation enthalpies indicates that the production Tlx Ga1-x As with Tl concentration of at least 8% is possible.

  20. 用f(1)、f(0)、f(-1)表示f(x)=ax2+bx+c解竞赛题

    Institute of Scientific and Technical Information of China (English)

    严启国; 陈纯亮

    2003-01-01

    @@ 设函数f(x)=ax2+bx+c(-1≤x≤1),则f(1)=a+b+c,f(0)=c,f(-1)=a-b+c,解得a=1/2f(1)+1/2f(-1)-f(0),b=1/2f(1)-1/2f(-1),c=f(0),从而有f(x)=[1/2f(1)+1/2f(-1)-f(0)]x2+[1/2f(1)-1/2f(-1)]x+f(0),利用这一表示形式可以解下列竞赛题.

  1. Evolution of non-synchronized binary systems

    Institute of Scientific and Technical Information of China (English)

    黄润乾; 曾艺蓉

    2000-01-01

    A model for binary evolution is introduced which can determine whether the rotation of components is synchronized with the orbital motion, and can calculate the evolution of both the synchronized and non-synchronized binary systems. With this model, the evolution of a binary system consisting of a 9 M star and a 6 M star is studied with mass transfer Case B. The result shows that the synchronization of the rotational and orbital periods can be reached when the binary system is a detached system and before the occurrence of the first mass transfer. After the onset of the first mass transfer, the binary system becomes non-synchronized. The mass accepted component (the secondary) rotates faster with a period much smaller than that of the orbital motion.

  2. Evolution of non-synchronized binary systems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for binary evolution is introduced which can determine whether the rotation of components is synchronized with the orbital motion, and can calculate the evolution of both the synchronized and non-synchronized binary systems. With this model, the evolution of a binary system consisting of a 9 M⊙ star and a 6 M⊙ star is studied with mass transfer Case B. The result shows that the synchronization of the rotational and orbital periods can be reached when the binary system is a detached system and before the occurrence of the first mass transfer. After the onset of the first mass transfer, the binary system becomes non-synchronized. The mass accepted component (the secondary) rotates faster with a period much smaller than that of the orbital motion.

  3. Planet Scattering Around Binaries: Ejections, Not Collisions

    CERN Document Server

    Smullen, Rachel A; Shannon, Andrew

    2016-01-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically effects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Asid...

  4. Binary Cepheids from optical interferometry

    CERN Document Server

    Gallenne, A; Mérand, A; Monnier, J D; Pietrzyński, J Breitfelder G; Gieren, W

    2013-01-01

    Classical Cepheid stars have been considered since more than a century as reliable tools to estimate distances in the universe thanks to their Period-Luminosity (P-L) relationship. Moreover, they are also powerful astrophysical laboratories, providing fundamental clues for studying the pulsation and evolution of intermediate-mass stars. When in binary systems, we can investigate the age and evolution of the Cepheid, estimate the mass and distance, and constrain theoretical models. However, most of the companions are located too close to the Cepheid (1-40 mas) to be spatially resolved with a 10-meter class telescope. The only way to spatially resolve such systems is to use long-baseline interferometry. Recently, we have started a unique and long-term interferometric program that aims at detecting and characterizing physical parameters of the Cepheid companions, with as main objectives the determination of accurate masses and geometric distances.

  5. Record-Breaking Eclipsing Binary

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    A new record holder exists for the longest-period eclipsing binary star system: TYC-2505-672-1. This intriguing system contains a primary star that is eclipsed by its companion once every 69 years with each eclipse lasting several years!120 Years of ObservationsIn a recent study, a team of scientists led by Joseph Rodriguez (Vanderbilt University) characterizes the components of TYC-2505-672-1. This binary star system consists of an M-type red giant star that undergoes a ~3.45-year-long, near-total eclipse with a period of ~69.1 years. This period is more than double that of the previous longest-period eclipsing binary!Rodriguez and collaborators combined photometric observations of TYC-2505-672-1 by the Kilodegree Extremely Little Telescope (KELT) with a variety of archival data, including observations by the American Association of Variable Star Observers (AAVSO) network and historical data from the Digital Access to a Sky Century @ Harvard (DASCH) program.In the 120 years spanned by these observations, two eclipses are detected: one in 1942-1945 and one in 2011-2015. The authors use the observations to analyze the components of the system and attempt to better understand what causes its unusual light curve.Characterizing an Unusual SystemObservations of TYC-2505-672-1 plotted from 1890 to 2015 reveal two eclipses. (The blue KELT observations during the eclipse show upper limits only.) [Rodriguez et al. 2016]By modeling the systems emission, Rodriguez and collaborators establish that TYC-2505-672-1 consists of a 3600-K primary star thats the M giant orbited by a small, hot, dim companion thats a toasty 8000 K. But if the companion is small, why does the eclipse last several years?The authors argue that the best model of TYC-2505-672-1 is one in which the small companion star is surrounded by a large, opaque circumstellar disk. Rodriguez and collaborators suggest that the companion could be a former red giant whose atmosphere was stripped from it, leaving behind

  6. Binary mixtures of chiral gases

    CERN Document Server

    Presilla, Carlo

    2015-01-01

    A possible solution of the well known paradox of chiral molecules is based on the idea of spontaneous symmetry breaking. At low pressure the molecules are delocalized between the two minima of a given molecular potential while at higher pressure they become localized in one minimum due to the intermolecular dipole-dipole interactions. Evidence for such a phase transition is provided by measurements of the inversion spectrum of ammonia and deuterated ammonia at different pressures. In particular, at pressure greater than a critical value no inversion line is observed. These data are well accounted for by a model previously developed and recently extended to mixtures. In the present paper, we discuss the variation of the critical pressure in binary mixtures as a function of the fractions of the constituents.

  7. Interrupted Binary Mass Transfer in Star Clusters

    CERN Document Server

    Leigh, Nathan W C; Toonen, Silvia

    2016-01-01

    Binary mass transfer is at the forefront of some of the most exciting puzzles of modern astrophysics, including Type Ia supernovae, gamma-ray bursts, and the formation of most observed exotic stellar populations. Typically, the evolution is assumed to proceed in isolation, even in dense stellar environments such as star clusters. In this paper, we test the validity of this assumption via the analysis of a large grid of binary evolution models simulated with the SeBa code. For every binary, we calculate analytically the mean time until another single or binary star comes within the mean separation of the mass-transferring binary, and compare this time-scale to the mean time for stable mass transfer to occur. We then derive the probability for each respective binary to experience a direct dynamical interruption. The resulting probability distribution can be integrated to give an estimate for the fraction of binaries undergoing mass transfer that are expected to be disrupted as a function of the host cluster pro...

  8. Fast algorithms for generating binary holograms

    CERN Document Server

    Stuart, Dustin; Kuhn, Axel

    2014-01-01

    We describe three algorithms for generating binary-valued holograms. Our methods are optimised for producing large arrays of tightly focussed optical tweezers for trapping particles. Binary-valued holograms allow us to use a digital mirror device (DMD) as the display element, which is much faster than other alternatives. We describe how our binary amplitude holograms can be used to correct for phase errors caused by optical aberrations. Furthermore, we compare the speed and accuracy of the algorithms for both periodic and arbitrary arrangements of traps, which allows one to choose the ideal scheme depending on the circumstances.

  9. Pd-Si binary bulk metallic glass

    Institute of Scientific and Technical Information of China (English)

    YAO KeFu; CHEN Na

    2008-01-01

    Pd80+xSi20-x (x=0, 1, and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing and water quenching or air cooling. Thermal analysis results show that with increasing Si content, the glass transition temperature Tg, the initial crystallization temperature Tx and the onset crystalliza-tion temperature Tp of Pd-Si binary glassy alloys increase. Moreover, the super-cooled liquid region reaches 61 K. It indicates that Pd-Si binary alloys possess large glass forming ability, which can be greatly improved by fluxing treatment.

  10. Pd-Si binary bulk metallic glass

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Pd80+xSi20-x (x=0,1,and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing and water quenching or air cooling. Thermal analysis results show that with increasing Si content,the glass transition temperature Tg,the initial crystallization temperature Tx and the onset crystalliza-tion temperature Tp of Pd-Si binary glassy alloys increase. Moreover,the super-cooled liquid region reaches 61 K. It indicates that Pd-Si binary alloys possess large glass forming ability,which can be greatly improved by fluxing treatment.

  11. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2014-01-01

    We evaluate a binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Prior research has shown this procedure to robustly induce risk neutrality when subjects are given a single risk task defined over objective probabilities. Drawing a sample from...... the same subject population, we find evidence that the binary lottery procedure also induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation of subjective probabilities in subjects...

  12. Revised photometric elements of eight eclipsing binaries

    Science.gov (United States)

    Mezzetti, M.; Predolin, F.; Giuricin, G.; Mardirossian, F.

    1980-10-01

    Photoelectric lightcurves of eight eclipsing binaries, known as detached systems, have been reanalysed by means of Wood's model in order to obtain homogeneous photometric elements. All binaries are confirmed to be detached. TU Cam, CW CMa, YZ Cas, CW Eri, CO Lac and EE Peg appear to be normal main-sequence (or near main-sequence) detached systems, but only the absolute elements of CO Lac are well-known. The detached binaries EK Cep and IQ Per are shown to be anomalous.

  13. Cassini states for black hole binaries

    OpenAIRE

    Correia, Alexandre C. M.

    2015-01-01

    Cassini states correspond to the equilibria of the spin axis of a body when its orbit is perturbed. They were initially described for planetary satellites, but the spin axes of black hole binaries also present this kind of equilibria. In previous works, Cassini states were reported as spin-orbit resonances, but actually the spin of black hole binaries is in circulation and there is no resonant motion. Here we provide a general description of the spin dynamics of black hole binary systems base...

  14. Busting Up Binaries: Encounters Between Compact Binaries and a Supermassive Black Hole

    CERN Document Server

    Addison, Eric; Larson, Shane

    2015-01-01

    Given the stellar density near the galactic center, close encounters between compact object binaries and the supermassive black hole are a plausible occurrence. We present results from a numerical study of close to 13 million such encounters. Consistent with previous studies, we corroborate that, for binary systems tidally disrupted by the black hole, the component of the binary remaining bound to the hole has eccentricity ~ 0.97 and circularizes dramatically by the time it enters the classical LISA band. Our results also show that the population of surviving binaries merits attention. These binary systems experience perturbations to their internal orbital parameters with potentially interesting observational consequences. We investigated the regions of parameter space for survival and estimated the distribution of orbital parameters post-encounter. We found that surviving binaries harden and their eccentricity increases, thus accelerating their merger due gravitational radiation emission and increasing the p...

  15. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Haghighipour, Nader [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Kaltenegger, Lisa [MPIA, Koenigstuhl 17, Heidelberg, D-69117 (Germany)

    2013-11-10

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.

  16. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    International Nuclear Information System (INIS)

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results

  17. Binaries Like to be Twins: Implications for Doubly Degenerate Binaries, the Supernova Ia Rate and Other Interacting Binaries

    CERN Document Server

    Pinsonneault, M H

    2006-01-01

    The recent sample of 21 detached eclipsing binaries in the Small Magellanic Cloud (Harries et al. 2003, Hilditch et al. 2005) provides a valuable test of the binary mass function for massive stars. We show that 50% of detached binaries have companions with very similar masses, q=M_2/M_1 > 0.87, where M_1, M_2 denote the masses of the two binary components, M_1 > M_2. A Salpeter relative mass function for the secondary is very strongly excluded, and the data is consistent with a flat mass function containing 55% of the systems and a ``twin'' population with q>0.95 containing the remainder. We also survey the vast existing literature discussing the mass ratio in binaries and conclude that a significant twin population (of more than 20-25%) exists in binaries that are likely to interact across a broad range of stellar masses and metallicity. Interactions involving nearly equal mass stars have distinctly different properties than those involving stars of unequal mass; the secondaries will tend to be evolved and t...

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

    OpenAIRE

    Desidera, S.; Barbieri, M.

    2006-01-01

    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 compa...

  19. Binaries in the Hipparcos data: Keep digging

    CERN Document Server

    Pourbaix, D; Jorissen, A

    2004-01-01

    Among the 120 000 objects in the Hipparcos catalogue, only 235 were fitted with an orbital model. Besides these 235 original astrometric binaries, most Hipparcos entries with a known spectroscopic orbit (extrasolar planet or stellar companion) have now been re-processed, as part of the on-going construction of the 9th Catalogue of Spectroscopic Binary Orbits (SB9, available at http://sb9.astro.ulb.ac.be). The pitfalls and successes of this re-processing are discussed in various contexts, like (i) orbital inclinations: the holy grail for extrasolar planets (ii) searching for binaries without a priori knowledge of their spectroscopic orbital elements, and application to barium stars (iii) why not all SB9 entries yield acceptable astrometric solutions? The lessons learned from this study are useful to devise the best possible binary-detection and orbit-determination algorithms for future astrometric missions like GAIA.

  20. A mesoscopic model for binary fluids

    CERN Document Server

    Echeverria, C; Alvarez-Llamoza, O; Orozco-Guillén, E E; Morales, M; Cosenza, M G

    2016-01-01

    We propose a model to study symmetric binary fluids, based in the mesoscopic molecular simulation technique known as multiparticle collision, where space and state variables are continuous while time is discrete. We include a repulsion rule to simulate segregation processes that does not require the calculation of the interaction forces between particles, thus allowing the description of binary fluids at a mesoscopic scale. The model is conceptually simple, computationally efficient, maintains Galilean invariance, and conserves the mass and the energy in the system at micro and macro scales; while momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as density profile, width of the interface, phase separation and phase growth. We also apply the model to study binary fluids in crowded environments with consistent results.

  1. Searching for Pulsars in Close Binary Systems

    CERN Document Server

    Jouteux, S; Stappers, B W; Jonker, P; Van der Klis, M

    2001-01-01

    We present a detailed mathematical analysis of the Fourier response of binary pulsar signals whose frequencies are modulated by circular orbital motion. The fluctuation power spectrum of such signals is found to be \

  2. Evolution of Binary Stars in Multiple-Population Globular Clusters - II. Compact Binaries

    CERN Document Server

    Hong, Jongsuk; Sollima, Antonio; McMillan, Stephen L W; D'Antona, Franca; D'Ercole, Annibale

    2016-01-01

    We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters.We show that as a consequence of the initial differences in the structural properties of the first-generation (FG) and the second-generation (SG) populations and the effects of dynamical processes on binary stars, the SG binary fraction decreases more rapidly than that of the FG population. The difference between the FG and SG binary fraction is qualitatively similar to but quantitatively smaller than that found for wider binaries in our previous investigations.The evolution of the radial variation of the binary fraction is driven by the interplay between binary segregation, ionization and ejection. Ionization and ejection counteract in part the effects of mass segregation but for compact binaries the effects of segregation dominate and the inner binary fraction increases during the cluster evolution. We explore the variation of the difference between the FG an...

  3. Binary is Good: A Binary Inference Framework for Primary User Separation in Cognitive Radio Networks

    CERN Document Server

    Nguyen, Huy; Han, Zhu

    2010-01-01

    Primary users (PU) separation concerns with the issues of distinguishing and characterizing primary users in cognitive radio (CR) networks. We argue the need for PU separation in the context of collaborative spectrum sensing and monitor selection. In this paper, we model the observations of monitors as boolean OR mixtures of underlying binary latency sources for PUs, and devise a novel binary inference algorithm for PU separation. Simulation results show that without prior knowledge regarding PUs' activities, the algorithm achieves high inference accuracy. An interesting implication of the proposed algorithm is the ability to effectively represent n independent binary sources via (correlated) binary vectors of logarithmic length.

  4. Dixie Valley Bottoming Binary Unit

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale [Terra-Gen Sierra Holdings, LLC, Reno, NV (United States)

    2014-12-21

    This binary plant is the first air cooled, 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 hydrocarbon based cycle are not necessary. The unit is largely modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. The Air Cooled Condensers (ACC), equipment piping, and Balance of Plant (BOP) piping were constructed at site. This project further demonstrates the technical feasibility of using low temperature brine for geothermal power utilization. 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, 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.

  5. Copula-based bivariate binary response models

    OpenAIRE

    Winkelmann, Rainer

    2009-01-01

    The bivariate probit model is frequently used for estimating the effect of an endogenous binary regressor on a binary outcome variable. This paper discusses simple modifications that maintain the probit assumption for the marginal distributions while introducing non-normal dependence among the two variables using copulas. Simulation results and evidence from two applications, one on the effect of insurance status on ambulatory expenditure and one on the effect of completing high school on sub...

  6. Diffusion in ordered binary solid systems

    International Nuclear Information System (INIS)

    This thesis contains contributions to the field of diffusion in ordered binary solid systems. An extensive experimental investigation of the self diffusion in CoGa is presented. The results of these diffusion measurements strongly suggest that a substantial part of the atomic migration is caused by a new type of defect. A quantitative description of the atomic displacements via this defect is given. Finally computer simulations are presented of diffusion and ordering in binary solid systems. (Auth.)

  7. GAIA survey of galactic eclipsing binaries

    OpenAIRE

    Zwitter, Tomaz

    2002-01-01

    General importance and capabilities of observations of eclipsing binaries by the forthcoming ESA mission GAIA are discussed. Availability of spectroscopic observations and a large number of photometric bands on board will make it possible to reliably determine physical parameters for $\\sim 10^5$ binary stars. It is stressed that current methods of object by object analysis will have to be modified and included in an automatic analysis pipeline.

  8. Binary nature of the Barium stars

    International Nuclear Information System (INIS)

    We present radial-velocity spectrometer observations that indicate that Ba II stars are binary systems. The secondary stars of these systems have low masses, consistent with their being degenerate objects which have lost mass onto their primaries in a previous stage of evolution. It is suggested that the Population II equivalents, the CH stars, may also be binary systems. This may be related to the fact that they are found only in globular clusters of the lowest central concentration

  9. Binary compact object inspiral: Detection expectations

    Indian Academy of Sciences (India)

    Vassiliki Kalogera

    2004-10-01

    We review the current estimates of binary compact object inspiral rates in particular in view of the recently discovered highly relativistic binary pulsar J0737-3039. One of the robust results is that, because of this discovery, the rate estimates for binary neutron stars have increased by a factor of 6-7 independent of any uncertainties related to the pulsar population properties. This rate increase has dramatic implications for gravitational wave detectors. For initial LIGO, the most probable detection rates for double neutron star (DNS) inspirals is 1 event/(5{250) yr; at 95% confidence we obtain rates up to 1/1.5 yr. For advanced LIGO, the most probable rates are 20-1000 events/yr. These predictions, for the first time, bring the expectations for DNS detections by initial LIGO to the astrophysically relevant regime. We also use our models to predict that the large-scale Parkes multibeam pulsar survey with acceleration searches could detect an average of three to four binary pulsars similar to those known at present. In comparison, rate estimates for binaries with black holes are derived based on binary evolution calculation, and based on the optimistic ends of the ranges, remain an important candidate for inspiral detection in the next few years. We also consider another aspect of the detectability of binary inspiral: the effect of precession on the detection efficiency of astrophysically relevant binaries. Based on our current astrophysical expectations, large tilt angles are not favored. As a result the decrease in detection rate varies rather slowly with black hole spin magnitude and is within 20-30% of the maximum possible values.

  10. Absorption by XeCl* excimer molecules of their own emission of the B-X transition (λ = 308 nm) in a dense Ar-Xe-CCl4 medium upon pumping by fast electrons and uranium-235 fission fragments

    Science.gov (United States)

    Mis'kevich, A. I.; Dyuzhov, Yu. A.; Suvorov, A. A.

    2016-08-01

    Luminescence of dense Ar-Xe-CCl4 gas mixtures with a low CCl4 content upon pumping by fast electrons and uranium-235 fission fragments is studied by spectroscopic methods. It is found that, in a cell with a resonator tuned to the B-X transition of the XeCl* molecule (λ = 308 nm), the D-state population of the XeCl* excimer molecule (the D-X transition, λ = 235 nm) depends on the B-state population and increases by many times with increasing B-state population of the XeCl* molecule. The stimulated absorption coefficient k = 1.2 × 10-16 of B-X transition emission of the XeCl* molecule (λmax = 308 nm), which leads to population of the D-state of this molecule, and the coefficient of amplification μ = 2.5 × 10-4 cm-1 of B-X transition emission of the Xe Cl* molecule (λ = 308 nm) are measured upon pumping by uranium- 235 fission fragments with the specific energy input into the gas medium of ~60 mJ/cm3 and a specific power of energy input of about 240 W/cm3.

  11. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  12. Spectroscopic subsystems in nearby wide binaries

    CERN Document Server

    Tokovinin, Andrei

    2015-01-01

    Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5-m telescope to study short-period systems. Data reduction is described, mean and individual RVs of 163 observed objects are given. New spectroscopic binaries are discovered or suspected in 17 objects, for some of them orbital periods could be determined. Subsystems are efficiently detected even in a single observation by double lines and/or by the RV difference between the components of visual binaries. The potential of this detection technique is quantified by simulation and used for statistical assessment of 96 wide binaries within 67pc. It is found that 43 binaries contain at least one subsystem and the occurrence of subsystems is equally probable in either primary or secondary components. The frequency of subsystems and their periods match the simple prescription proposed by the author (2014, AJ, 147, 87). The remaining 53 simple wide binaries with a median projected separation of 1300AU have the distri...

  13. Coronal activity from the ASAS eclipsing binaries

    CERN Document Server

    Szczygiel, D M; Paczynski, B; Pojmanski, G; Pilecki, B

    2008-01-01

    We combine the catalogue of eclipsing binaries from the All Sky Automated Survey (ASAS) with the ROSAT All Sky Survey (RASS). The combination results in 836 eclipsing binaries that display coronal activity and is the largest sample of active binary stars assembled to date. By using the (V-I) colors of the ASAS eclipsing binary catalogue, we are able to determine the distances and thus bolometric luminosities for the majority of eclipsing binaries that display significant stellar activity. A typical value for the ratio of soft X-ray to bolometric luminosity is L_X/L_bol ~ a few x 10^-4, similar to the ratio of soft X-ray to bolometric flux F_X/F_bol in the most active regions of the Sun. Unlike rapidly rotating isolated late-type dwarfs -- stars with significant outer convection zones -- a tight correlation between Rossby number and activity of eclipsing binaries is absent. We find evidence for the saturation effect and marginal evidence for the so-called "super-saturation" phenomena. Our work shows that wide-...

  14. Spectroscopic Orbits for Kepler FOV Eclipsing Binaries

    Science.gov (United States)

    Matson, Rachel A.; Gies, Douglas R.; Williams, Stephen J.; Guo, Zhao

    2013-02-01

    We are currently involved in a four year program of precise eclipsing binary photometry with the NASA Kepler Observatory. Our goal is to search for variations in minimum light timing for intermediate mass eclipsing binaries. Such periodic variations will reveal the reflex motion caused by any distant, low mass object that orbits the close binary. it Kepler's unprecedented accuracy and continuous observations provide a unique opportunity to detect the low mass companions that are predicted to result from the angular momentum of the natal cloud. The goal of this proposal is to obtain blue spectra of short period (0.9-6d) eclipsing binaries, derive radial velocities, and produce a double-lined spectroscopic orbit (as well as estimates of the stellar effective temperatures, gravities, and metallicities). Combined with the it Kepler light curve, we will determine very accurate masses and radii for the members of the close binary, which will yield the mass-inclination product M_3 sin i for any companions detected by light travel time or other effects. An extended sample of eclipsing binaries with longer periods (up to 50d) is now being investigated to test whether the presence of a tertiary companion declines with increasing period. We propose to obtain a single spectrum at quadrature for the brightest 48 stars in this expanded sample to characterize the effective temperatures and total mass contained in these systems.

  15. Design and Implementation of BDB, the Binary Star Database

    Science.gov (United States)

    Kaygorodov, P.; Kovaleva, D.; Malkov, O.

    2013-02-01

    The Binary star DataBase (BDB, http://bdb.inasan.ru) is created to provide liasons between binary star catalogue data of various origin. Information on different observational types of binaries is obtained from heterogeneous sources of data - astronomical catalogues and surveys. The database allows a variety of query options useful for selected stars investigation purposes, for binary observations planning, and for construction and examination of binary datasets with certain characteristics.

  16. Exploring the Birth of Binary Stars

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    More than half of all stars are thought to be in binary or multiple star systems. But how do these systems form? The misaligned spins of some binary protostars might provide a clue.Two Formation ModelsIts hard to tell how multiple-star systems form, since these systems are difficult to observe in their early stages. But based on numerical simulations, there are two proposed models for the formation of stellar binaries:Turbulent fragmentationTurbulence within a single core leads to multiple dense clumps. These clumps independently collapse to form stars that orbit each other.Disk fragmentationGravitational instabilities in a massive accretion disk cause the formation of a smaller, secondary disk within the first, resulting in two stars that orbit each other.Log column density for one of the authors simulated binary systems, just after the formation of two protostars. Diamonds indicate the protostar positions. [Adapted from Offner et al. 2016]Outflows as CluesHow can we differentiate between these formation mechanisms? Led by Stella Offner (University of Massachusetts), a team of scientists has suggested that the key isto examine the alignment of the stars protostellar outflows jets that are often emitted from the poles of young, newly forming stars.Naively, wed expect that disk fragmentation would produce binary stars with common angular momentum. As the stars spins would be aligned, they would therefore also launch protostellar jets that were aligned with each other. Turbulent fragmentation, on the other hand, would cause the stars to have independent angular momentum. This would lead to randomly oriented spins, so the protostellar jets would be misaligned.Snapshots from the authors simulations. Left panel of each pair: column density; green arrows giveprotostellar spin directions. Right panel: synthetic observations produced from the simulations; cyan arrows giveprotostellar outflow directions. [Offner et al. 2016]Simulations of FragmentationIn order to better

  17. New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems

    CERN Document Server

    Bluhm, P; Vanzi, L; Soto, M G; Vos, J; Wittenmyer, R A; Olivares, F; Drass, H; Mennickent, R E; Vuckovic, M; Rojo, P; Melo, C H F

    2016-01-01

    We report the discovery of 24 spectroscopic binary companions to giant stars. We fully constrain the orbital solution for 6 of these systems. We cannot unambiguously derive the orbital elements for the remaining stars because the phase coverage is incomplete. Of these stars, 6 present radial velocity trends that are compatible with long-period brown dwarf companions.The orbital solutions of the 24 binary systems indicate that these giant binary systems have a wide range in orbital periods, eccentricities, and companion masses. For the binaries with restricted orbital solutions, we find a range of orbital periods of between $\\sim$ 97-1600 days and eccentricities of between $\\sim$ 0.1-0.4. In addition, we studied the metallicity distribution of single and binary giant stars. We computed the metallicity of a total of 395 evolved stars, 59 of wich are in binary systems. We find a flat distribution for these binary stars and therefore conclude that stellar binary systems, and potentially brown dwarfs, have a diffe...

  18. Birth of Massive Black Hole Binaries

    Energy Technology Data Exchange (ETDEWEB)

    Colpi, M.; /Milan Bicocca U.; Dotti, M.; /Insubria U., Como; Mayer, L.; /Zurich, ETH; Kazantzidis, S.; /KIPAC, Menlo Park

    2007-11-19

    If massive black holes (BHs) are ubiquitous in galaxies and galaxies experience multiple mergers during their cosmic assembly, then BH binaries should be common albeit temporary features of most galactic bulges. Observationally, the paucity of active BH pairs points toward binary lifetimes far shorter than the Hubble time, indicating rapid inspiral of the BHs down to the domain where gravitational waves lead to their coalescence. Here, we review a series of studies on the dynamics of massive BHs in gas-rich galaxy mergers that underscore the vital role played by a cool, gaseous component in promoting the rapid formation of the BH binary. The BH binary is found to reside at the center of a massive self-gravitating nuclear disc resulting from the collision of the two gaseous discs present in the mother galaxies. Hardening by gravitational torques against gas in this grand disc is found to continue down to sub-parsec scales. The eccentricity decreases with time to zero and when the binary is circular, accretion sets in around the two BHs. When this occurs, each BH is endowed with it own small-size ({approx}< 0.01 pc) accretion disc comprising a few percent of the BH mass. Double AGN activity is expected to occur on an estimated timescale of {approx}< 1 Myr. The double nuclear point-like sources that may appear have typical separation of {approx}< 10 pc, and are likely to be embedded in the still ongoing starburst. We note that a potential threat of binary stalling, in a gaseous environment, may come from radiation and/or mechanical energy injections by the BHs. Only short-lived or sub-Eddington accretion episodes can guarantee the persistence of a dense cool gas structure around the binary necessary for continuing BH inspiral.

  19. Gravitational wave background from binary systems

    International Nuclear Information System (INIS)

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter Ω(f), commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, Ω(f) is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the frequencies of all existing and planned detectors. A semi-analytical formula for Ω(f) is derived in the case of stellar binaries (containing white dwarfs, neutron stars or stellar-mass black holes). Besides a realistic expectation of the level of background, upper and lower limits are given, to account for the uncertainties in some astrophysical parameters such as binary coalescence rates. One interesting result concerns all current and planned ground-based detectors (including the Einstein Telescope). In their frequency range, the background of binaries is resolvable and only sporadically present. In other words, there is no stochastic background of binaries for ground-based detectors.

  20. Massive gaseous discs around SMBH binaries: Binary decay and tidal disruptions

    Directory of Open Access Journals (Sweden)

    Brem P.

    2012-12-01

    Full Text Available We investigate the evolution of black hole binaries embedded within geometrically thin gas discs. Our results imply that such discs can produce black hole mergers for relatively low-mass binaries, and that a significant population of eccentric binaries might exist at separations of a few 0.01 pc. These binaries may be detectable due to the time-variable accretion on to the black holes. If the disc fragments, then the newly-born stars will continue driving the binary to its coalescence, although at a slower rate. Interestingly, our preliminary analysis shows that these stars will be disrupted at a rate of ∼10−4–2 · 10−5 events per year per system.

  1. Nonconservative Mass Transfer in Massive Binaries and the Formation of Wolf-Rayet+O Binaries

    CERN Document Server

    Shao, Yong

    2016-01-01

    The mass transfer efficiency during the evolution of massive binaries is still uncertain. We model the mass transfer processes in a grid of binaries to investigate the formation of Wolf-Rayet+O (WR+O) binaries, taking into account two kinds of non-conservative mass transfer models: Model I with rotation-dependent mass accretion and Model II of half mass accretion. Generally the mass transfer in Model I is more inefficient, with the average efficiency in a range of $\\sim0.2-0.7$ and $ \\lesssim0.2 $ for Case A and Case B mass transfer, respectively. We present the parameter distributions for the descendant WR+O binaries. By comparing the modeled stellar mass distribution with the observed Galactic WR+O binaries, we find that highly non-conservative mass transfer is required.

  2. Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near B 110 in the B BX-BY Waste Management Area

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; mccain, r. G.; Lindenmeier, Clark W.; Orr, Robert D.; Legore, Virginia L.; Clayton, Ray E.; Lindberg, Michael J.; Kutynakov, I. V.; Baum, Steven R.; Geiszler, Keith N.; Valenta, Michelle M.; Vickerman, Tanya S.; Royack, Lisa J.

    2008-09-11

    This report was revised in September 2008 to remove acid-ectractable sodium data from Table 4.17. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in December 2002. The overall goal of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediment from within the B-BX-BY Waste Management Area. This report is the third in a series of three reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from a borehole installed approximately 4.5 m (15 ft) northeast of tank B- 110 (borehole 299-E33-46).

  3. Impact of photoluminescence temperature and growth parameter on the exciton localized in BxGa1-xAs/GaAs epilayers grown by MOCVD

    Science.gov (United States)

    Hidouri, Tarek; Saidi, Faouzi; Maaref, Hassen; Rodriguez, Philippe; Auvray, Laurent

    2016-10-01

    In this work, BxGa1-xAs/GaAs epilayers with three different boron compositions were elaborated by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrate. Structural study using High resolution X-ray diffraction (HRXRD) spectroscopy and Atomic Force Microscopy (AFM) have been used to estimate the boron fraction. The luminescence keys were carried out as functions of temperature in the range 10-300 K, by the techniques of photoluminescence (PL). The low PL temperature has shown an abnormal emission appeared at low energy side witch attributed to the recombination through the deep levels. In all samples, the PL peak energy and the full width at half maximum (FWHM), present an anomalous behavior as a result of the competition process between localized and delocalized carriers. We propose the Localized-state Ensemble model to explain the unusual photoluminescence behaviors. Electrical carriers generation, thermal escape, recapture, radiative and non-radiative lifetime are taken into account. The temperature-dependent photoluminescence measurements were found to be in reasonable agreement with the model of localized states. We controlled the evolution of such parameters versus composition by varying the V/III ratio to have a quantitative and qualitative understanding of the recombination mechanisms. At high temperature, the model can be approximated to the band-tail-state emission.

  4. Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area

    Energy Technology Data Exchange (ETDEWEB)

    Lindenmeier, Clark W.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Lindberg, Michael J.; Clayton, Ray E.; Legore, Virginia L.; Kutnyakov, Igor V.; Baum, Steven R.; Geiszler, Keith N.; Brown, Christopher F.; Valenta, Michelle M.; Vickerman, Tanya S.; Royack, Lisa J.

    2008-09-11

    This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003. The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).

  5. Stability of multiplanet systems in binaries

    CERN Document Server

    Marzari, F

    2016-01-01

    When exploring the stability of multiplanet systems in binaries, two parameters are normally exploited: the critical semimajor axis ac computed by Holman and Wiegert (1999) within which planets are stable against the binary perturbations, and the Hill stability limit Delta determining the minimum separation beyond which two planets will avoid mutual close encounters. Our aim is to test whether these two parameters can be safely applied in multiplanet systems in binaries or if their predictions fail for particular binary orbital configurations. We have used the frequency map analysis (FMA) to measure the diffusion of orbits in the phase space as an indicator of chaotic behaviour. First we revisited the reliability of the empirical formula computing ac in the case of single planets in binaries and we find that, in some cases, it underestimates by 10-20% the real outer limit of stability. For two planet systems, the value of Delta is close to that computed for planets around single stars, but the level of chaoti...

  6. Orbital eccentricities in primordial black hole binaries

    Science.gov (United States)

    Cholis, Ilias; Kovetz, Ely D.; Ali-Haïmoud, Yacine; Bird, Simeon; Kamionkowski, Marc; Muñoz, Julian B.; Raccanelli, Alvise

    2016-10-01

    It was recently suggested that the merger of ˜30 M⊙ primordial black holes (PBHs) may provide a significant number of events in gravitational-wave observatories over the next decade, if they make up an appreciable fraction of the dark matter. Here we show that measurement of the eccentricities of the inspiralling binary black holes can be used to distinguish these binaries from those produced by more traditional astrophysical mechanisms. These PBH binaries are formed on highly eccentric orbits and can then merge on time scales that in some cases are years or less, retaining some eccentricity in the last seconds before the merger. This is to be contrasted with massive-stellar-binary, globular-cluster, or other astrophysical origins for binary black holes (BBHs) in which the orbits have very effectively circularized by the time the BBH enters the observable LIGO window. Here we discuss the features of the gravitational-wave signals that indicate this eccentricity and forecast the sensitivity of LIGO and the Einstein Telescope to such effects. We show that if PBHs make up the dark matter, then roughly one event should have a detectable eccentricity given LIGO's expected sensitivity and observing time of six years. The Einstein Telescope should see O (10 ) such events after ten years.

  7. Urey Prize Lecture: Binary Minor Planets

    Science.gov (United States)

    Margot, J. L.

    2004-11-01

    The discovery of binary systems in the near-Earth, main belt, and Kuiper belt populations provides an abundance of new data that expand our knowledge of the physics and chemistry of the solar system. Binary minor planets form as a result of collisional, tidal, and capture processes that are important to study as they play major roles in the formation and evolution of planetary systems. The frequency of occurrence of such processes directly reflects the dynamical environment in the various populations. Observations of binaries provide a powerful way to measure the bulk properties of small bodies, which in turn lead to inferences about their composition and internal structure. These data may offer a rare glimpse of what physical and chemical conditions prevailed when protoplanets formed, and what subsequent evolution took place. In the case of the Kuiper Belt, the study of a handful of binaries forces us to rethink how dense and how bright these bodies are, and to significantly revise our current mass estimates for the entire population. The number of known binary minor planets has increased dramatically over the past few years, with roughly ten new discoveries each year. I will attempt to summarize recent developments, with examples drawn from my observations with the Hubble, Palomar, Keck, Arecibo and Goldstone telescopes.

  8. The binary white dwarf LHS 3236

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2013-12-10

    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.

  9. A Model for Contact Binary Systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A model for contact binary systems is presented, which incorporates the following special features: a) The energy exchange between the components is based on the understanding that the energy exchange is due to the release of potential, kinetic and thermal energies of the exchanged mass. b) A special form of mass and angular momentum loss occurring in contact binaries is losses via the outer Lagrangian point. c) The effects of spin, orbital rotation and tidal action on the stellar structure as well as the effect of meridian circulation on the mixing of the chemical elements are considered. d) The model is valid not only for low-mass contact binaries but also for high-mass contact binaries. For illustration, we used the model to trace the evolution of a massive binary system consisting of one 12M⊙ and one 5M⊙ star. The result shows that the start and end of the contact stage fall within the semi-detached phase during which the primary continually transfers mass to the secondary. The time span of the contact stage is short and the mass transfer rate is very large. Therefore, the contact stage can be regarded as a special part of the semi-detached phase with a large mass transfer rate. Both mass loss through the outer Lagrangian point and oscillation between contact and semi-contact states can occur during the contact phase, and the effective temperatures of the primary and the secondary are almost equal.

  10. An interferometric view of binary stars

    CERN Document Server

    Boffin, Henri M J

    2016-01-01

    The study of binary stars is critical to apprehend many of the most interesting classes of stars. Moreover, quite often, the study of stars in binary systems is our only mean to constrain stellar properties, such as masses and radii. Unfortunately, a great fraction of the most interesting binaries are so compact that they can only be apprehended by high-resolution techniques, mostly by interferometry. I present some results highlighting the use of interferometry in the study of binary stars, from finding companions and deriving orbits, determining the mass and radius of stars, to studying mass transfer in symbiotic stars, and tackling luminous blue variables. In particular, I show how interferometric studies using the PIONIER instrument have allowed us to confirm a dichotomy within symbiotic stars, obtain masses of stars with a precision better than 1%, and help us find a new Eta Carinae-like system. I will also illustrate the benefits for the study of binary stars one would get from upgrading the VLT Interfe...

  11. Planet scattering around binaries: ejections, not collisions

    Science.gov (United States)

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-09-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically affects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multiplanet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

  12. Orbital eccentricities in primordial black holes binaries

    CERN Document Server

    Cholis, Ilias; Ali-Haïmoud, Yacine; Bird, Simeon; Kamionkowski, Marc; Muñoz, Julian B; Raccanelli, Alvise

    2016-01-01

    It was recently suggested that the merger of $\\sim30\\,M_\\odot$ primordial black holes (PBHs) may provide a significant number of events in gravitational-wave observatories over the next decade, if they make up an appreciable fraction of the dark matter. Here we show that measurement of the eccentricities of the inspiralling binary black holes can be used to distinguish these binaries from those produced by more traditional astrophysical mechanisms. These PBH binaries are formed on highly eccentric orbits and can then merge on timescales that in some cases are years or less, retaining some eccentricity in the last seconds before the merger. This is to be contrasted with massive-stellar-binary, globular-cluster, or other astrophysical origins for binary black holes (BBHs) in which the orbits have very effectively circularized by the time the BBH enters the observable LIGO window. Here we discuss the features of the gravitational-wave signals that indicate this eccentricity and forecast the sensitivity of LIGO a...

  13. INTEGRAL & RXTE View of Gamma-ray Binaries

    OpenAIRE

    Jian LI; Torres, Diego F.; Zhang, Shu; WANG, JIANMIN

    2013-01-01

    Gamma-ray binaries are X-ray binaries with gamma-ray emissions. Their multi-wavelength emissions range from radio, optical, X-ray and to very high energy (TeV). X-ray emissions are crucial to understand the nature of gamma-ray binaries. INTEGRAL and RXTE have covered and monitored most of the gamma-ray binaries in hard and soft X-rays. Here we report the results of several gamma-ray binaries and possible gamma-ray binaries from INTEGRAL and RXTE.

  14. Gravitational waves from spinning eccentric binaries

    CERN Document Server

    Csizmadia, Péter; Rácz, István; Vasúth, Mátyás

    2012-01-01

    This paper is to introduce a new software called CBwaves which provides a fast and accurate computational tool to determine the gravitational waveforms yielded by generic spinning binaries of neutron stars and/or black holes on eccentric orbits. This is done within the post-Newtonian (PN) framework by integrating the equations of motion and the spin precession equations while the radiation field is determined by a simultaneous evaluation of the analytic waveforms. In applying CBwaves various physically interesting scenarios have been investigated. In particular, we have studied the appropriateness of the adiabatic approximation, and justified that the energy balance relation is indeed insensitive to the specific form of the applied radiation reaction term. By studying eccentric binary systems it is demonstrated that circular template banks are very ineffective in identifying binaries even if they possess tiny residual orbital eccentricity. In addition, by investigating the validity of the energy balance relat...

  15. Optimized Reversible Binary-Coded Decimal Adders

    DEFF Research Database (Denmark)

    Thomsen, Michael Kirkedal; Glück, Robert

    2008-01-01

    Abstract Babu and Chowdhury [H.M.H. Babu, A.R. Chowdhury, Design of a compact reversible binary coded decimal adder circuit, Journal of Systems Architecture 52 (5) (2006) 272-282] recently proposed, in this journal, a reversible adder for binary-coded decimals. This paper corrects and optimizes...... in reversible logic design by drastically reducing the number of garbage bits. Specialized designs benefit from support by reversible logic synthesis. All circuit components required for optimizing the original design could also be synthesized successfully by an implementation of an existing synthesis algorithm....... Keywords: Reversible logic circuit; Full-adder; Half-adder; Parallel adder; Binary-coded decimal; Application of reversible logic synthesis...

  16. Gravitational wave background from binary systems

    CERN Document Server

    Rosado, Pablo A

    2011-01-01

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter $\\Omega(f)$, commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, $\\Omega(f)$ is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the ...

  17. The Expressive Power of Binary Submodular Functions

    CERN Document Server

    Zivny, Stanislav; Jeavons, Peter G

    2008-01-01

    It has previously been an open problem whether all Boolean submodular functions can be decomposed into a sum of binary submodular functions over a possibly larger set of variables. This problem has been considered within several different contexts in computer science, including computer vision, artificial intelligence, and pseudo-Boolean optimisation. Using a connection between the expressive power of valued constraints and certain algebraic properties of functions, we answer this question negatively. Our results have several corollaries. First, we characterise precisely which submodular functions of arity 4 can be expressed by binary submodular functions. Next, we identify a novel class of submodular functions of arbitrary arities which can be expressed by binary submodular functions, and therefore minimised efficiently using a so-called expressibility reduction to the Min-Cut problem. More importantly, our results imply limitations on this kind of reduction and establish for the first time that it cannot be...

  18. Binary Code Disassembly for Reverse Engineering

    Directory of Open Access Journals (Sweden)

    Marius Popa

    2013-01-01

    Full Text Available The disassembly of binary file is used to restore the software application code in a readable and understandable format for humans. Further, the assembly code file can be used in reverse engineering processes to establish the logical flows of the computer program or its vulnerabilities in real-world running environment. The paper highlights the features of the binary executable files under the x86 architecture and portable format, presents issues of disassembly process of a machine code file and intermediate code, disassembly algorithms which can be applied to a correct and complete reconstruction of the source file written in assembly language, and techniques and tools used in binary code disassembly.

  19. Rapid Compact Binary Coalescence Parameter Estimation

    Science.gov (United States)

    Pankow, Chris; Brady, Patrick; O'Shaughnessy, Richard; Ochsner, Evan; Qi, Hong

    2016-03-01

    The first observation run with second generation gravitational-wave observatories will conclude at the beginning of 2016. Given their unprecedented and growing sensitivity, the benefit of prompt and accurate estimation of the orientation and physical parameters of binary coalescences is obvious in its coupling to electromagnetic astrophysics and observations. Popular Bayesian schemes to measure properties of compact object binaries use Markovian sampling to compute the posterior. While very successful, in some cases, convergence is delayed until well after the electromagnetic fluence has subsided thus diminishing the potential science return. With this in mind, we have developed a scheme which is also Bayesian and simply parallelizable across all available computing resources, drastically decreasing convergence time to a few tens of minutes. In this talk, I will emphasize the complementary use of results from low latency gravitational-wave searches to improve computational efficiency and demonstrate the capabilities of our parameter estimation framework with a simulated set of binary compact object coalescences.

  20. Binary Particle Model of Weak Interactions

    CERN Document Server

    Ndili, F N

    2011-01-01

    We introduce the new concept of binary particle as the basic matter unit that participates in weak interactions and not any one fermion singly. We state the quantum numbers of this binary particle, and show the concept leads us to a natural explanation of the standard model puzzle of the origin of flavor mixing and the CKM matrix. Certain other puzzles of the standard model such as the absence of flavor changing neutral currents (FCNC), are also explained naturally by the binary particle model. These puzzles are currently thought to be esoteric properties of electro weak interactions that have origins in physics beyond the standard model at some ultra high energy scales. We show that this is not necessarily the case.

  1. Modeling Flows Around Merging Black Hole Binaries

    CERN Document Server

    van Meter, James R; Miller, M Coleman; Reynolds, Christopher S; Centrella, Joan M; Baker, John G; Boggs, William D; Kelly, Bernard J; McWilliams, Sean T

    2009-01-01

    Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a step towards solving this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We find qualitative differences in collision and outflow speeds, including a signature of the merger when the net angular momentum of the matter is low, between the results from single and binary black holes, and between nonrotating and rotating holes in binaries. If future magnetohydrodynamic results confirm ...

  2. Nonlinear Tides in Close Binary Systems

    CERN Document Server

    Weinberg, Nevin N; Quataert, Eliot; Burkart, Josh

    2011-01-01

    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 effects: three-mode nonlinear interactions and nonlinear excitation of modes by the time-varying gravitational potential of the companion. This paper presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism is applicable to binaries containing stars, planets, or compact objects, we focus on solar type stars with stellar or planetary companions. Our primary results include: (1) The linear tidal solution often used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited gravity waves are unstable to parametric resonance for companion masses M' > 10-100 M_Earth at orbital periods P = 1-10 days. The nearly static equilibrium tide is, however, parametrically s...

  3. Hybrid Black-Hole Binary Initial Data

    Science.gov (United States)

    Mundim, Bruno C.; Kelly, Bernard J.; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-01-01

    "Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class. Quantum Grav. 27:114005 (2010)], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculations was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features."

  4. The Circulation Pattern in Simulated Contact Binaries

    Science.gov (United States)

    Motl, Patrick M.; Frank, J.; Tohline, J. E.

    2006-06-01

    We present a three-dimensional hydrodynamical simulation of an initially symmetric (equal mass) binary where both components are marginally in contact. The simulation evolves the binary through approximately 150 orbital periods and within the first 20 orbits, a global velocity field is established that carries material between both components. In the equatorial plane, the flow is along a figure eight pattern with streams of material sliding past one another in the neighborhood of the inner Lagrange point. For our chosen equation of state, mass transfer is ultimately unstable in this binary though the growth time is long compared to the orbital period. We are therefore able to observe that the circulation pattern, once established, is quite close to steady state. We explore the role that similar steady state flows may play in real contact systems.

  5. Memory effect from spinning unbound binaries

    CERN Document Server

    De Vittori, Lorenzo; Gupta, Anuradha; Jetzer, Philippe

    2014-01-01

    We present a recently developed prescription to obtain ready-to-use gravitational wave (GW) polarization states for spinning compact binaries on hyperbolic orbits. We include leading order spin-orbit interactions, invoking 1.5PN-accurate quasi-Keplerian parametrization for the radial part of the orbital dynamics. We also include radiation reaction effects on $h_+$ and $h_{\\times}$ during the interaction. In the GW signals from spinning binaries there is evidence of the memory effect in both polarizations, in contrast to the non-spinning case, where only the cross polarizations exhibits non-vanishing amplitudes at infinite time. We also compute 1PN-accurate GW polarization states for non-spinning compact binaries in unbound orbits in a fully parametric way, and compare them with existing waveforms.

  6. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenegger, Lisa [MPIA, Koenigstuhl 17, D-69117 Heidelberg (Germany); Haghighipour, Nader, E-mail: kaltenegger@mpia.de [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States)

    2013-11-10

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886.

  7. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    International Nuclear Information System (INIS)

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886

  8. Automated analysis of eclipsing binary lightcurves with EBAS. II. Statistical analysis of OGLE LMC eclipsing binaries

    CERN Document Server

    Mazeh, T; Tamuz, O; Mazeh, Tsevi; North, Pierre; Tamuz, Omer

    2006-01-01

    In the first paper of this series we presented EBAS, a new fully automated algorithm to analyse the lightcurves of eclipsing binaries, based on the EBOP code. Here we apply the new algorithm to the whole sample of 2580 binaries found in the OGLE LMC photometric survey and derive the orbital elements for 1931 systems. To obtain the statistical properties of the short-period binaries of the LMC we construct a well defined subsample of 938 eclipsing binaries with main-sequence B-type primaries. Correcting for observational selection effects, we derive the distributions of the fractional radii of the two components and their sum, the brightness ratios and the periods of the short-period binaries. Somewhat surprisingly, the results are consistent with a flat distribution in log P between 2 and 10 days. We also estimate the total number of binaries in the LMC with the same characteristics, and not only the eclipsing binaries, to be about 5000. This figure leads us to suggest that 0.7 +- 0.4 percent of the main-sequ...

  9. Applications Of Binary Image Analysis Techniques

    Science.gov (United States)

    Tropf, H.; Enderle, E.; Kammerer, H. P.

    1983-10-01

    After discussing the conditions where binary image analysis techniques can be used, three new applications of the fast binary image analysis system S.A.M. (Sensorsystem for Automation and Measurement) are reported: (1) The human view direction is measured at TV frame rate while the subject's head is free movable. (2) Industrial parts hanging on a moving conveyor are classified prior to spray painting by robot. (3) In automotive wheel assembly, the eccentricity of the wheel is minimized by turning the tyre relative to the rim in order to balance the eccentricity of the components.

  10. Toroidal Horizons in Binary Black Hole Mergers

    OpenAIRE

    Bohn, Andy; Kidder, Lawrence E.; Teukolsky, Saul A.

    2016-01-01

    We find the first binary black hole event horizon with a toroidal topology. It had been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology, but such a phase has never been seen prior to this work. In all previous binary black hole simulations, in the coordinate slicing used to evolve the black holes, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. ...

  11. Binaries in the Hipparcos data: Keep digging

    OpenAIRE

    Pourbaix, D.; Jancart, S.; Jorissen, A.

    2004-01-01

    Among the 120 000 objects in the Hipparcos catalogue, only 235 were fitted with an orbital model. Besides these 235 original astrometric binaries, most Hipparcos entries with a known spectroscopic orbit (extrasolar planet or stellar companion) have now been re-processed, as part of the on-going construction of the 9th Catalogue of Spectroscopic Binary Orbits (SB9, available at http://sb9.astro.ulb.ac.be). The pitfalls and successes of this re-processing are discussed in various contexts, like...

  12. Rotation and massive close binary evolution

    CERN Document Server

    Langer, N; Yoon, S -C; Hunter, I; Brott, I; Lennon, D J; de Mink, S E; Verheijdt, M

    2008-01-01

    We review the role of rotation in massive close binary systems. Rotation has been advocated as an essential ingredient in massive single star models. However, rotation clearly is most important in massive binaries where one star accretes matter from a close companion, as the resulting spin-up drives the accretor towards critical rotation. Here, we explore our understanding of this process, and its observable consequences. When accounting for these consequences, the question remains whether rotational effects in massive single stars are still needed to explain the observations.

  13. Binary black holes' effects on electromagnetic fields.

    Science.gov (United States)

    Palenzuela, Carlos; Anderson, Matthew; Lehner, Luis; Liebling, Steven L; Neilsen, David

    2009-08-21

    In addition to producing gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as a possible enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves. PMID:19792706

  14. Speckle interferometric observations of close binary stars

    CERN Document Server

    Saha, S K; Yeswanth, L; Anbazhagan, P

    2002-01-01

    Speckle interferometric technique is employed to record a series of hundreds of short-exposure images of several close binary stars with sub-arcsecond separation through a narrow band filter at the Cassegrain focus of the 2.34 meter (m) Vainu Bappu telescope (VBT), situated at Vainu Bappu Observatory (VBO), Kavalur, India. The data are recorded sequentially by a Peltier-cooled intensified CCD camera with 10 ms exposure. The auto-correlation method is applied to determine the angular separations and position angles of these binary systems.

  15. Photometric Solutions of Some Contact ASAS Binaries

    CERN Document Server

    Gezer, I

    2015-01-01

    We present the first light curve solution of 6 contact binary systems which are chosen from the ASAS catalog. The photometric elements and the estimated absolute parameters of all systems are obtained with the light curve analyses. We calculated the values of degree of contact for the systems. The location of the targets on the Hertzsprung-Russell diagram and the mass-radius plane is compared to the other well-known contact binaries and the evolutionary status of the systems are also discussed.

  16. Photometric solutions of some contact ASAS binaries

    Science.gov (United States)

    Gezer, İ.; Bozkurt, Z.

    2016-04-01

    We present the first light curve solution of 6 contact binary systems which are chosen from the ASAS catalog. The photometric elements and the estimated absolute parameters of all systems are obtained with the light curve analyses. We calculated the values of degree of contact for the systems. The location of the targets on the Hertzsprung-Russell diagram and the mass-radius plane is compared to the other well-known contact binaries and the evolutionary status of the systems are also discussed.

  17. Thermodynamics of binary gas adsorption in nanopores.

    Science.gov (United States)

    Dutta, Sujeet; Lefort, Ronan; Morineau, Denis; Mhanna, Ramona; Merdrignac-Conanec, Odile; Saint-Jalmes, Arnaud; Leclercq, Théo

    2016-09-21

    MCM-41 nanoporous silicas show a very high selectivity for monoalcohols over aprotic molecules during adsorption of a binary mixture in the gas phase. We present here an original use of gravimetric vapour sorption isotherms to characterize the role played by the alcohol hydrogen-bonding network in the adsorption process. Beyond simple selectivity, vapour sorption isotherms measured for various compositions help to completely unravel at the molecular level the step by step adsorption mechanism of the binary system in the nanoporous solid, from the first monolayers to the complete liquid condensation. PMID:27532892

  18. VLSI binary multiplier using residue number systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsi, F.; Di Cola, A.

    1982-01-01

    The idea of performing multiplication of n-bit binary numbers using a hardware based on residue number systems is considered. This paper develops the design of a VLSI chip deriving area and time upper bounds of a n-bit multiplier. To perform multiplication using residue arithmetic, numbers are converted from binary to residue representation and, after residue multiplication, the result is reconverted to the original notation. It is shown that the proposed design requires an area a=o(n/sup 2/ log n) and an execution time t=o(log/sup 2/n). 7 references.

  19. Quasi periodic oscillations in black hole binaries

    CERN Document Server

    Motta, S E

    2016-01-01

    Fast time variability is the most prominent characteristic of accreting systems and the presence of quasi periodic oscillations (QPOs) is a constant in all accreting systems, from cataclysmic variables to AGNs, passing through black hole and neutron star X-ray binaries and through the enigmatic ultra-luminous X-ray sources. In this paper I will briefly review the current knowledge of QPOs in black hole X-ray binaries, mainly focussing on their observed properties, but also mentioning the most important models that have been proposed to explain the origin of QPOs over the last decades.

  20. Spin supplementary conditions for spinning compact binaries

    CERN Document Server

    Mikóczi, Balázs

    2016-01-01

    We consider the different spin supplementary conditions (SSC) for a spinning compact binary with the leading-order spin-orbit (SO) interaction. The Lagrangian of the binary system can be constructed but it is acceleration-dependent in two cases of SSC. We rewrite the generalized Hamiltonian formalism proposed by Ostrogradsky and compute the conservative quantities and the dissipative part of relative motion during the gravitational radiation of each SSCs. We give the orbital elements and observed quantities of the SO dynamics, for instance the energy and the orbital angular momentum losses and waveforms and discuss their SSC dependence.

  1. Pulsations in close binaries: challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Maceroni C.

    2015-01-01

    Full Text Available CoRoT and Kepler provided a precious by-product: a number of eclipsing binaries containing variable stars and, among these, non-radial pulsators. This providential occurrence allows combining independent information from two different phenomena whose synergy yields scientific results well beyond those from the single sources. In particular, the analysis of pulsations in eclipsing binary components throws light on the internal structure of the pulsating star, on the system evolution, and on the role of tidal forces in exciting the oscillations. The case study of the Kepler target KIC 3858884 is illustrative of the difficulties of analysis and of the achievements in this rapidly developing field.

  2. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed...... validity of any strategic equilibrium behavior, or even the customary independence axiom. We show that subjects sampled from our population are generally risk averse when lotteries are defined over monetary outcomes, and that the binary lottery procedure does indeed induce a statistically significant shift...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  3. Binary Sparse Phase Retrieval via Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available This paper presents the Simulated Annealing Sparse PhAse Recovery (SASPAR algorithm for reconstructing sparse binary signals from their phaseless magnitudes of the Fourier transform. The greedy strategy version is also proposed for a comparison, which is a parameter-free algorithm. Sufficient numeric simulations indicate that our method is quite effective and suggest the binary model is robust. The SASPAR algorithm seems competitive to the existing methods for its efficiency and high recovery rate even with fewer Fourier measurements.

  4. Neutron-Star-Black-Hole Binaries Produced by Binary-Driven Hypernovae.

    Science.gov (United States)

    Fryer, Chris L; Oliveira, F G; Rueda, J A; Ruffini, R

    2015-12-01

    Binary-driven hypernovae (BdHNe) within the induced gravitational collapse paradigm have been introduced to explain energetic (E_{iso}≳10^{52}  erg), long gamma-ray bursts (GRBs) associated with type Ic supernovae (SNe). The progenitor is a tight binary composed of a carbon-oxygen (CO) core and a neutron-star (NS) companion, a subclass of the newly proposed "ultrastripped" binaries. The CO-NS short-period orbit causes the NS to accrete appreciable matter from the SN ejecta when the CO core collapses, ultimately causing it to collapse to a black hole (BH) and producing a GRB. These tight binaries evolve through the SN explosion very differently than compact binaries studied in population synthesis calculations. First, the hypercritical accretion onto the NS companion alters both the mass and the momentum of the binary. Second, because the explosion time scale is on par with the orbital period, the mass ejection cannot be assumed to be instantaneous. This dramatically affects the post-SN fate of the binary. Finally, the bow shock created as the accreting NS plows through the SN ejecta transfers angular momentum, braking the orbit. These systems remain bound even if a large fraction of the binary mass is lost in the explosion (well above the canonical 50% limit), and even large kicks are unlikely to unbind the system. Indeed, BdHNe produce a new family of NS-BH binaries unaccounted for in current population synthesis analyses and, although they may be rare, the fact that nearly 100% remain bound implies that they may play an important role in the compact merger rate, important for gravitational waves that, in turn, can produce a new class of ultrashort GRBs.

  5. BROWN DWARF BINARIES FROM DISINTEGRATING TRIPLE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Reipurth, Bo [Institute for Astronomy and NASA Astrobiology Institute University of Hawaii, 640 N. Aohoku Place, Hilo, HI 96720 (United States); Mikkola, Seppo, E-mail: reipurth@ifa.hawaii.edu, E-mail: Seppo.Mikkola@utu.fi [Tuorla Observatory, University of Turku, Väisäläntie 20, Piikkiö (Finland)

    2015-04-15

    Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi–Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to

  6. Model-independent inference on compact-binary observations

    CERN Document Server

    Mandel, Ilya; Colonna, Andrea; Stevenson, Simon; Tiňo, Peter; Veitch, John

    2016-01-01

    The recent advanced LIGO detections of gravitational waves from merging binary black holes enhance the prospect of exploring binary evolution via gravitational-wave observations of a population of compact-object binaries. In the face of uncertainty about binary formation models, model-independent inference provides an appealing alternative to comparisons between observed and modelled populations. We describe a procedure for clustering in the multi-dimensional parameter space of observations that are subject to significant measurement errors. We apply this procedure to a mock data set of population-synthesis predictions for the masses of merging compact binaries convolved with realistic measurement uncertainties, and demonstrate that we can accurately distinguish subpopulations of binary neutron stars, binary black holes, and mixed black hole -- neutron star binaries.

  7. Evolution of Binary Stars in Multiple-Population Globular Clusters

    CERN Document Server

    Hong, Jongsuk; Sollima, Antonio; McMillan, Stephen L W; D'Antona, Franca; D'Ercole, Annibale

    2015-01-01

    The discovery of multiple stellar populations in globular clusters has implications for all the aspects of the study of these stellar systems. In this paper, by means of N-body simulations, we study the evolution of binary stars in multiple-population clusters and explore the implications of the initial differences in the spatial distribution of different stellar populations for the evolution and survival of their binary stars. Our simulations show that initial differences between the spatial distribution of first-generation (FG) and second-generation (SG) stars can leave a fingerprint in the current properties of the binary population. SG binaries are disrupted more efficiently than those of the FG population resulting in a global SG binary fraction smaller than that of the FG. As for surviving binaries, dynamical evolution produces a difference between the SG and the FG binary binding energy distribution with the SG population characterized by a larger fraction of high binding energy (more bound) binaries. ...

  8. Formation and evolution of X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We review recent progress in theoretical understanding of X-ray binaries,which has largely been driven by new observations.We select several topics including formation of compact low-mass X-ray binaries,the evolutionary connection between low-mass X-ray binaries and binary and millisecond radio pulsars,and ultraluminous X-ray sources,to illustrate the interplay between theories and observations.

  9. Orbits of Ten Visual Binary Stars

    Institute of Scientific and Technical Information of China (English)

    B.Novakovi(c)

    2007-01-01

    We present the orbits of ten visual binary stars:WDS 01015+6922.WDS 01424-0645,WDS 01461+6349,WDS 04374-0951,WDS 04478+5318,WDS 05255-0033,WDS 05491+6248,WDS 06404+4058,WDS 07479-1212,and WDS 18384+0850.We have also determined their masses,dynamical parallaxes and ephemerides.

  10. Chemically homogeneous evolution in massive binaries

    CERN Document Server

    de Mink, S E; Langer, N; Pols, O R

    2010-01-01

    Rotation can have severe consequences for the evolution of massive stars. It is now considered as one of the main parameters, alongside mass and metallicity that determine the final fate of single stars. In massive, fast rotating stars mixing processes induced by rotation may be so efficient that helium produced in the center is mixed throughout the envelope. Such stars evolve almost chemically homogeneously. At low metallicity they remain blue and compact, while they gradually evolve into Wolf-Rayet stars and possibly into progenitors of long gamma-ray bursts. In binaries this type of evolution may occur because of (I) tides in very close binaries, as a result of (II) spin up by mass transfer, as result of (III) a merger of the two stars and (IV) when one of the components in the binary was born with a very high initial rotation rate. As these stars stay compact, the evolutionary channels are very different from what classical binary evolutionary models predict. In this contribution we discuss examples of ne...

  11. Binaries are the best single stars

    CERN Document Server

    de Mink, S E; Izzard, R G

    2010-01-01

    Stellar models of massive single stars are still plagued by major uncertainties. Testing and calibrating against observations is essential for their reliability. For this purpose one preferably uses observed stars that have never experienced strong binary interaction, i.e. "true single stars". However, the binary fraction among massive stars is high and identifying "true single stars" is not straight forward. Binary interaction affects systems in such a way that the initially less massive star becomes, or appears to be, single. For example, mass transfer results in a widening of the orbit and a decrease of the luminosity of the donor star, which makes it very hard to detect. After a merger or disruption of the system by the supernova explosion, no companion will be present. The only unambiguous identification of "true single stars" is possible in detached binaries, which contain two main-sequence stars. For these systems we can exclude the occurrence of mass transfer since their birth. A further advantage is ...

  12. The Evolution of Relativistic Binary Progenitor Systems

    CERN Document Server

    Francischelli, G J; Brown, G E

    2001-01-01

    Relativistic binary pulsars, such as B1534+12 and B1913+16 are characterized by having close orbits with a binary separation of ~ 3 R_\\sun. The progenitor of such a system is a neutron star, helium star binary. The helium star, with a strong stellar wind, is able to spin up its compact companion via accretion. The neutron star's magnetic field is then lowered to observed values of about 10^{10} Gauss. As the pulsar lifetime is inversely proportional to its magnetic field, the possibility of observing such a system is, thus, enhanced by this type of evolution. We will show that a nascent (Crab-like) pulsar in such a system can, through accretion-braking torques (i.e. the "propeller effect") and wind-induced spin-up rates, reach equilibrium periods that are close to observed values. Such processes occur within the relatively short helium star lifetimes. Additionally, we find that the final outcome of such evolutionary scenarios depends strongly on initial parameters, particularly the initial binary separation a...

  13. Structure Map for Embedded Binary Alloy Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, C.W.; Shin, S.J.; Liao, C.Y.; Guzman, J.; Stone, P.R.; Watanabe, M.; Ager III, J.W.; Haller, E.E.; Chrzan, D.C.

    2008-09-20

    The equilibrium structure of embedded nanocrystals formed from strongly segregating binary-alloys is considered within a simple thermodynamic model. The model identifies two dimensionlessinterface energies that dictate the structure, and allows prediction of the stable structure for anychoice of these parameters. The resulting structure map includes three distinct nanocrystal mor-phologies: core/shell, lobe/lobe, and completely separated spheres.

  14. The Orbital Decay of Embedded Binary Stars

    CERN Document Server

    Stahler, Steven W

    2009-01-01

    Young binaries within dense molecular clouds are subject to dynamical friction from ambient gas. Consequently, their orbits decay, with both the separation and period decreasing in time. A simple analytic expression is derived for this braking torque. The derivation utilizes the fact that each binary acts as a quadrupolar source of acoustic waves. The acoustic disturbance has the morphology of a two-armed spiral and carries off angular momentum. From the expression for the braking torque, the binary orbital evolution is also determined analytically. This type of merger may help explain the origin of high-mass stars. If infrared dark clouds, with peak densities up to 10^7 cm^{-3}, contain low-mass binaries, those with separations less than 100 AU merge within about 10^5 yr. During the last few thousand years of the process, the rate of mechanical energy deposition in the gas exceeds the stars' radiative luminosity. Successive mergers may lead to the massive star formation believed to occur in these clouds.

  15. Numerical simulations of compact object binaries

    OpenAIRE

    Pfeiffer, Harald P.

    2012-01-01

    Coalescing compact object binaries consisting of black holes and/or Neutron stars are a prime target for ground-based gravitational wave detectors. This article reviews the status of numerical simulations of these systems, with an emphasis on recent progress.

  16. Performance of binary FSK data transmission systems

    Science.gov (United States)

    Batson, B. H.

    1973-01-01

    Matched-filter detection of binary signals is discussed in terms of the probability of bit error. The equations for the probability of error are derived for coherent phase shift keying, and coherent frequency shift keying (FSK). Suboptimum detection of FSK signals is also discussed for discriminators.

  17. Constraining Binary Stellar Evolution With Pulsar Timing

    Science.gov (United States)

    Ferdman, Robert D.; Stairs, I. H.; Backer, D. C.; Burgay, M.; Camilo, F.; D'Amico, N.; Demorest, P.; Faulkner, A.; Hobbs, G.; Kramer, M.; Lorimer, D. R.; Lyne, A. G.; Manchester, R.; McLaughlin, M.; Nice, D. J.; Possenti, A.

    2006-06-01

    The Parkes Multibeam Pulsar Survey has yielded a significant number of very interesting binary and millisecond pulsars. Two of these objects are part of an ongoing timing study at the Green Bank Telescope (GBT). PSR J1756-2251 is a double-neutron star (DNS) binary system. It is similar to the original Hulse-Taylor binary pulsar system PSR B1913+16 in its orbital properties, thus providing another important opportunity to test the validity of General Relativity, as well as the evolutionary history of DNS systems through mass measurements. PSR J1802-2124 is part of the relatively new and unstudied "intermediate-mass" class of binary system, which typically have spin periods in the tens of milliseconds, and/or relatively massive (> 0.7 solar masses) white dwarf companions. With our GBT observations, we have detected the Shapiro delay in this system, allowing us to constrain the individual masses of the neutron star and white dwarf companion, and thus the mass-transfer history, in this unusual system.

  18. Binary Quadratic Forms: A Historical View

    Science.gov (United States)

    Khosravani, Azar N.; Beintema, Mark B.

    2006-01-01

    We present an expository account of the development of the theory of binary quadratic forms. Beginning with the formulation and proof of the Two-Square Theorem, we show how the study of forms of the type x[squared] + ny[squared] led to the discovery of the Quadratic Reciprocity Law, and how this theorem, along with the concept of reduction relates…

  19. Spin frequency distributions of binary millisecond pulsars

    NARCIS (Netherlands)

    A. Papitto; D.F. Torres; N. Rea; T.M. Tauris

    2014-01-01

    Rotation-powered millisecond radio pulsars have been spun up to their present spin period by a 108−109 yr long X-ray-bright phase of accretion of matter and angular momentum in a low-to-intermediate mass binary system. Recently, the discovery of transitional pulsars that alternate cyclically between

  20. The Binary Pulsar: Gravity Waves Exist.

    Science.gov (United States)

    Will, Clifford

    1987-01-01

    Reviews the history of pulsars generally and the 1974 discovery of the binary pulsar by Joe Taylor and Russell Hulse specifically. Details the data collection and analysis used by Taylor and Hulse. Uses this discussion as support for Albert Einstein's theory of gravitational waves. (CW)

  1. Spectropolarimetry of single and binary stars

    CERN Document Server

    Harries, T J

    2004-01-01

    Spectropolarimetry is a photon-hungry technique that will reach fruition in the 8-m telescope age. Here I summarize some of the stellar spectropolarimetric research that my collaborators and I have undertaken, with particular emphasis on the circumstellar environment of massive stars, symbiotic binaries, and star formation.

  2. Testing the Binary Trigger Hypothesis in FUors

    Science.gov (United States)

    Green, Joel D.; Kraus, Adam L.; Rizzuto, Aaron C.; Ireland, Michael J.; Dupuy, Trent J.; Mann, Andrew W.; Kuruwita, Rajika

    2016-10-01

    We present observations of three FU Orionis objects (hereafter, FUors) with nonredundant aperture-mask interferometry at 1.59 μm and 2.12 μm that probe for binary companions on the scale of the protoplanetary disk that feeds their accretion outbursts. We do not identify any companions to V1515 Cyg or HBC 722, but we do resolve a close binary companion to V1057 Cyg that is at the diffraction limit (ρ =58.3+/- 1.4 mas or 30 ± 5 au) and currently much fainter than the outbursting star ({{Δ }}K\\prime =3.34+/- 0.10 mag). Given the flux excess of the outbursting star, we estimate that the mass of the companion (M∼ 0.25{M}ȯ ) is similar to or slightly below that of the FUor itself, and therefore it resembles a typical T Tauri binary system. Our observations only achieve contrast limits of {{Δ }}K\\prime ∼ 4 mag, and hence we are only sensitive to companions that were near or above the pre-outburst luminosity of the FUors. It remains plausible that FUor outbursts could be tied to the presence of a close binary companion. However, we argue from the system geometry and mass reservoir considerations that these outbursts are not directly tied to the orbital period (i.e., occurring at periastron passage), but instead must only occur infrequently.

  3. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes. PMID:25910104

  4. ANGULAR-MOMENTUM IN BINARY SPIRAL GALAXIES

    NARCIS (Netherlands)

    OOSTERLOO, T

    1993-01-01

    In order to investigate the relative orientations of spiral galaxies in pairs, the distribution of the angle between the spin-vectors for a new sample of 40 binary spiral galaxies is determined. From this distribution it is found, contrary to an earlier result obtained by Helou (1984), that there is

  5. Eclipsing Binaries with the Kepler Mission

    Science.gov (United States)

    Prsa, Andrej; Kepler Eclipsing Binary Working Group

    2012-05-01

    Kepler has revolutionized the eclipsing binary field by providing us essentially uninterrupted data of unprecedented quality. Out of 160,000 targets, we detected over 2500 eclipsing binaries. These range in orbital periods from as short as 0.3 days, all the way to several years, and encompass stellar types across the H-R diagram. In this talk I will present the collaborative effort of the Kepler Eclipsing Binary Working Group to study and characterize these systems on a statistical level: their distribution in periods, galactic latitude, spectral type, fundamental stellar properties and multiplicity as evidenced by eclipse timing variations. I will further show the gems that have sprung from this sample, which were modeled and interpreted to reveal intrinsically pulsating components, runaway encounters with massive tertiaries, stellar objects that populate the lowest end of the main sequence and circumbinary planets. I will critically review and discuss the causes of data systematics and detrending, and introduce a novel algorithm to classify light curves into morphological types using Locally Linear Embedding. Finally, I will touch on the dark side of eclipsing binaries as the primary cause of false positives in extrasolar planet detections with Kepler.

  6. Locating Restricted Facilities on Binary Maps

    CERN Document Server

    Andreica, Mugurel Ionut; Andreica, Madalina Ecaterina

    2008-01-01

    In this paper we consider several facility location problems with applications to cost and social welfare optimization, when the area map is encoded as a binary (0,1) mxn matrix. We present algorithmic solutions for all the problems. Some cases are too particular to be used in practical situations, but they are at least a starting point for more generic solutions.

  7. Bloch-Zener oscillations in binary superlattices.

    Science.gov (United States)

    Dreisow, F; Szameit, A; Heinrich, M; Pertsch, T; Nolte, S; Tünnermann, A; Longhi, S

    2009-02-20

    Bloch-Zener oscillations, i.e., the coherent superposition of Bloch oscillations and Zener tunneling between minibands of a binary lattice, are experimentally demonstrated for light waves in curved femtosecond laser-written waveguide arrays. Visualization of double-periodicity breathing and oscillation modes is reported, and synchronous tunneling leading to wave reconstruction is demonstrated.

  8. A Binary Teetering on the Edge

    Science.gov (United States)

    Motl, P. M.; D'Souza, M. C. R.; Tohline, J. E.; Frank, J.

    2005-05-01

    We present a fully three-dimensional hydrodynamical simulation of Roche lobe overflow in a binary near the stability boundary. This boundary separates evolutionary branches that correspond to either an accelerating mass transfer rate leading eventually to merger through tidal instability or to a decaying mass transfer rate as the orbit expands. The binary begins with a mass ratio of 0.4 (ratio of donor to accretor mass) and is initially assumed to be rotating synchronously. We treat the stellar components as simple polytropic fluids characterized by a polytropic index, n = 3/2. As the donor overflows its Roche lobe, the mass transfer rate initially accelerates before stabilizing and eventually dropping over a timescale of tens of orbits. We also note that for this particular binary, the accretion stream impacts on the surface of the donor rather than forming an accretion disk. This simulation allows us to measure the efficiency with which the accretion stream spins up the accretor in this "direct impact" scenario and the degree to which angular momentum is transfered back to the binary orbit via the tidal field.

  9. Face Alignment via Regressing Local Binary Features.

    Science.gov (United States)

    Ren, Shaoqing; Cao, Xudong; Wei, Yichen; Sun, Jian

    2016-03-01

    This paper presents a highly efficient and accurate regression approach for face alignment. Our approach has two novel components: 1) a set of local binary features and 2) a locality principle for learning those features. The locality principle guides us to learn a set of highly discriminative local binary features for each facial landmark independently. The obtained local binary features are used to jointly learn a linear regression for the final output. This approach achieves the state-of-the-art results when tested on the most challenging benchmarks to date. Furthermore, because extracting and regressing local binary features are computationally very cheap, our system is much faster than previous methods. It achieves over 3000 frames per second (FPS) on a desktop or 300 FPS on a mobile phone for locating a few dozens of landmarks. We also study a key issue that is important but has received little attention in the previous research, which is the face detector used to initialize alignment. We investigate several face detectors and perform quantitative evaluation on how they affect alignment accuracy. We find that an alignment friendly detector can further greatly boost the accuracy of our alignment method, reducing the error up to 16% relatively. To facilitate practical usage of face detection/alignment methods, we also propose a convenient metric to measure how good a detector is for alignment initialization.

  10. PARTICLE SEGREGATION IN FLUIDIZED BINARY-MIXTURES

    NARCIS (Netherlands)

    HOFFMANN, AC; JANSSEN, LPBM

    1993-01-01

    The particle segregation in fluidised beds consisting of different types of binary mixtures is shown to be governed by the same particle transport processes. The segregation behaviour of both ''different-density mixtures'' and ''equal-density mixtures'', two types of system which until now largely h

  11. Testing the Binary Trigger Hypothesis in FUors

    CERN Document Server

    Green, Joel D; Rizzuto, Aaron C; Ireland, Michael J; Dupuy, Trent J; Mann, Andrew W; Kuruwita, Rajika

    2016-01-01

    We present observations of three FU Orionis objects (hereafter, FUors) with nonredundant aperture-mask interferometry (NRM) at 1.59 um and 2.12 um that probe for binary companions on the scale of the protoplanetary disk that feeds their accretion outbursts. We do not identify any companions to V1515 Cyg or HBC 722, but we do resolve a close binary companion to V1057 Cyg that is at the diffraction limit (rho = 58.3 +/- 1.4 mas or 30 +/- 5 AU) and currently much fainter than the outbursting star (delta(K') = 3.34 +/- 0.10 mag). Given the flux excess of the outbursting star, we estimate that the mass of the companion (M ~ 0.25 Msun) is similar to or slightly below that of the FUor itself, and therefore it resembles a typical T Tauri binary system. Our observations only achieve contrast limits of delta(K') ~ 4 mag, and hence we are only sensitive to companions that were near or above the pre-outburst luminosity of the FUors. It remains plausible that FUor outbursts could be tied to the presence of a close binary ...

  12. Binary pulsars as dark-matter probes

    CERN Document Server

    Pani, Paolo

    2015-01-01

    During the motion of a binary pulsar around the galactic center, the pulsar and its companion experience a wind of dark-matter particles that can affect the orbital motion through dynamical friction. We show that this effect produces a characteristic seasonal modulation of the orbit and causes a secular change of the orbital period whose magnitude can be well within the astonishing precision of various binary-pulsar observations. Our analysis is valid for binary systems with orbital period longer than a day. By comparing this effect with pulsar-timing measurements, it is possible to derive model-independent upper bounds on the dark-matter density at different distances $D$ from the galactic center. For example, the precision timing of J1713+0747 imposes $\\rho_{\\rm DM}\\lesssim 10^5\\,{\\rm GeV/cm}^3$ at $D\\approx7\\,{\\rm kpc}$. The detection of a binary pulsar at $D\\lesssim 10\\,{\\rm pc}$ could provide stringent constraints on dark-matter halo profiles and on growth models of the central black hole. The Square Kil...

  13. Supermassive Black Hole Binaries: The Search Continues

    CERN Document Server

    Bogdanovic, Tamara

    2014-01-01

    Gravitationally bound supermassive black hole binaries (SBHBs) are thought to be a natural product of galactic mergers and growth of the large scale structure in the universe. They however remain observationally elusive, thus raising a question about characteristic observational signatures associated with these systems. In this conference proceeding I discuss current theoretical understanding and latest advances and prospects in observational searches for SBHBs.

  14. Binary translation using peephole translation rules

    Science.gov (United States)

    Bansal, Sorav; Aiken, Alex

    2010-05-04

    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.

  15. Echoes in X-ray Binaries

    CERN Document Server

    O'Brien, K; Hynes, R; Chen, W; Haswell, C; Still, M

    2002-01-01

    We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving lightcurves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulating the distribution of reprocessing regions, using geometrical and binary parameters. We construct best-fit time-delay transfer functions, showing the regions in the binary responsible for the reprocessing of X-rays. We have applied this model to observations of the Soft X-ray Transient, GRO j1655-40. We find the optical variability lags the X-ray variability with a mean time delay of 19.3$pm{2.2}$ seconds. This means that the outer regions of the accretion disc are the dominant reprocessing site in this system. On fitting the data to a simple geometric model, we derive a best-fit disk half-opening angle of 13.5$^{+2.1}_{-2.8}$ degrees, which is similar to that observe...

  16. Planetary nebula progenitors that swallow binary systems

    CERN Document Server

    Soker, Noam

    2015-01-01

    I propose that some irregular `messy' planetary nebulae owe their morphologies to triple-stellar evolution where tight binary systems are tidally and frictionally destroyed inside the envelope of asymptotic giant branch (AGB) stars. The tight binary system might breakup with one star leaving the system. In an alternative evolution, one of the stars of the brook-up tight binary system falls toward the AGB envelope with low specific angular momentum, and drowns in the envelope. In a different type of destruction process the drag inside the AGB envelope causes the tight binary system to merge. This releases gravitational energy within the AGB envelope, leading to a very asymmetrical envelope ejection, with an irregular and `messy' planetary nebula as a descendant. The evolution of the triple-stellar system before destruction can be in a full common envelope evolution (CEE) or in a grazing envelope evolution (GEE). Both before and after destruction the system might lunch pairs of opposite jets. One pronounced sig...

  17. Cassini states for black-hole binaries

    CERN Document Server

    Correia, Alexandre C M

    2016-01-01

    Cassini states correspond to equilibria of the spin axis of a celestial body when its orbit is perturbed. They were initially described for planetary satellites, but the spin axes of black-hole binaries also present this kind of equilibria. In previous works, Cassini states were reported as spin-orbit resonances, but actually the spin of black-hole binaries is in circulation and there is no resonant motion. Here we provide a general description of the spin dynamics of black-hole binary systems based on a Hamiltonian formalism. In absence of dissipation the problem is integrable and it is easy to identify all possible trajectories for the spin for a given value of the total angular momentum. As the system collapses due to radiation reaction, the Cassini states are shifted to different positions, which modifies the dynamics around them. This is why the final spin distribution may differ from the initial one. Our method provides a simple way of predicting the distribution of the spin of black-hole binaries at th...

  18. HI OBSERVATIONS OF BINARY SPIRAL GALAXIES

    NARCIS (Netherlands)

    OOSTERLOO, T; SHOSTAK, S

    1993-01-01

    Observations in the 21 cm line of neutral hydrogen made with the Arecibo- and the Westerbork radio telescopes are presented of a sample of binary spiral galaxies. Completed with optical information, these observations are used to determine the spatial orientation of the spin-vectors of the galaxies

  19. What's Next? Judging Sequences of Binary Events

    Science.gov (United States)

    Oskarsson, An T.; Van Boven, Leaf; McClelland, Gary H.; Hastie, Reid

    2009-01-01

    The authors review research on judgments of random and nonrandom sequences involving binary events with a focus on studies documenting gambler's fallacy and hot hand beliefs. The domains of judgment include random devices, births, lotteries, sports performances, stock prices, and others. After discussing existing theories of sequence judgments,…

  20. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  1. Non-binary or genderqueer genders.

    Science.gov (United States)

    Richards, Christina; Bouman, Walter Pierre; Seal, Leighton; Barker, Meg John; Nieder, Timo O; T'Sjoen, Guy

    2016-01-01

    Some people have a gender which is neither male nor female and may identify as both male and female at one time, as different genders at different times, as no gender at all, or dispute the very idea of only two genders. The umbrella terms for such genders are 'genderqueer' or 'non-binary' genders. Such gender identities outside of the binary of female and male are increasingly being recognized in legal, medical and psychological systems and diagnostic classifications in line with the emerging presence and advocacy of these groups of people. Population-based studies show a small percentage--but a sizable proportion in terms of raw numbers--of people who identify as non-binary. While such genders have been extant historically and globally, they remain marginalized, and as such--while not being disorders or pathological in themselves--people with such genders remain at risk of victimization and of minority or marginalization stress as a result of discrimination. This paper therefore reviews the limited literature on this field and considers ways in which (mental) health professionals may assist the people with genderqueer and non-binary gender identities and/or expressions they may see in their practice. Treatment options and associated risks are discussed. PMID:26753630

  2. Balanced binary trees in the Tamari lattice

    CERN Document Server

    Giraudo, Samuele

    2010-01-01

    We show that the set of balanced binary trees is closed by interval in the Tamari lattice. We establish that the intervals [T0, T1] where T0 and T1 are balanced trees are isomorphic as posets to a hypercube. We introduce tree patterns and synchronous grammars to get a functional equation of the generating series enumerating balanced tree intervals.

  3. Merging Compact Binaries in Hierarchical Triple Systems: Resonant Excitation of Binary Eccentricity

    CERN Document Server

    Liu, Bin; Yuan, Ye-Fei

    2015-01-01

    The merging of compact binaries play an important role in astrophysical context. The gravitational waves takes the angular momentum off the merging binary, which makes the orbit of the inner binary shrink. In this work, we study the secular dynamics of merging binary with a small perturber in hierarchical triple systems. From our numerical calculations, we find that the triple system goes through a resonant state between the apsidal precession rates of two orbits during the orbital decay, and the eccentricity of the inner orbit is excited, as well as the corresponding gravita- tional wave frequency. Our numerical results could be understood under the linear approximation of small orbital eccentricities and coplanar configuration. Especially, the resonant condition and the excited eccentricity can be estimated analytically.

  4. A decoding method of an n length binary BCH code through (n + 1n length binary cyclic code

    Directory of Open Access Journals (Sweden)

    TARIQ SHAH

    2013-09-01

    Full Text Available For a given binary BCH code Cn of length n = 2 s - 1 generated by a polynomial of degree r there is no binary BCH code of length (n + 1n generated by a generalized polynomial of degree 2r. However, it does exist a binary cyclic code C (n+1n of length (n + 1n such that the binary BCH code Cn is embedded in C (n+1n . Accordingly a high code rate is attained through a binary cyclic code C (n+1n for a binary BCH code Cn . Furthermore, an algorithm proposed facilitates in a decoding of a binary BCH code Cn through the decoding of a binary cyclic code C (n+1n , while the codes Cn and C (n+1n have the same minimum hamming distance.

  5. The Tarantula Massive Binary Monitoring: I. Observational campaign and OB-type spectroscopic binaries

    CERN Document Server

    Almeida, L A; Taylor, W; Barbá, R; Bonanos, A; Crowther, P; Damineli, A; de Koter, A; de Mink, S E; Evans, C J; Gieles, M; Grin, N J; Hénault-Brunet, V; Langer, N; Lennon, D; Lockwood, S; Apellániz, J Maíz; Moffat, A F J; Neijssel, C; Norman, C; Ramírez-Agudelo, O H; Richardson, N D; Schootemeijer, A; Shenar, T; Soszyński, I; Tramper, F; Vink, J S

    2016-01-01

    Massive binaries (MBs) play a crucial role in the Universe and knowing the distributions of their orbital parameters (OPs) is important for a wide range of topics, from stellar feedback to binary evolution channels, from the distribution of supernova types to gravitational wave progenitors. Yet, no direct measurements exist outside the Milky Way. The Tarantula Massive Binary Monitoring was designed to help fill this gap by obtaining multi-epoch radial velocity monitoring of 102 MBs in the 30 Dor. In this paper, we analyse 32 FLAMES/GIRAFFE observations of 93 O- and 7 B-type binaries. We performed a Fourier analysis and obtained orbital solutions for 82 systems: 51 single-lined and 31 double-lined spectroscopic binaries. Overall, the OPs and binary fraction are remarkably similar across the 30 Dor region and compared to existing Galactic samples (GSs). This indicates that within these domains environmental effects are of second order in shaping the properties of MBs. A small difference is found in the distribu...

  6. Binary-disk interaction. II. Gap-opening criteria for unequal-mass binaries

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle, Luciano; Escala, Andrés, E-mail: ldelvalleb@gmail.com [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile)

    2014-01-01

    We study the interaction of an unequal-mass binary with an isothermal circumbinary disk, motivated by the theoretical and observational evidence that after a major merger of gas-rich galaxies, a massive gaseous disk with a supermassive black hole binary will be formed in the nuclear region. We focus on the gravitational torques that the binary exerts on the disk and how these torques can drive the formation of a gap in the disk. This exchange of angular momentum between the binary and the disk is mainly driven by the gravitational interaction between the binary and a strong nonaxisymmetric density perturbation that is produced in the disk, in response to the presence of the binary. Using smoothed particle hydrodynamics numerical simulations, we test two gap-opening criteria, one that assumes the geometry of the density perturbation is an ellipsoid/thick spiral and another that assumes a flat spiral geometry for the density perturbation. We find that the flat spiral gap-opening criterion successfully predicts which simulations will have a gap in the disk and which will not. We also study the limiting cases predicted by the gap-opening criteria. Since the viscosity in our simulations is considerably smaller than the expected value in the nuclear regions of gas-rich merging galaxies, we conclude that in such environments the formation of a circumbinary gap is unlikely.

  7. Binary Disk interaction II: Gap-Opening criteria for unequal mass binaries

    CERN Document Server

    del Valle, Luciano

    2013-01-01

    We study the interaction between an unequal mass binary with an isothermal circumbinary disk, motivated by the theoretical and observational evidence that after a major merger of gas-rich galaxies, a massive gaseous disk with a SMBH binary will be formed in the nuclear region. We focus on the gravitational torques that the binary exerts onto the disk and how these torques can drive the formation of a gap in the disk. This exchange of angular momentum between the binary and the disk is mainly driven by the gravitational interaction between the binary and a strong non-axisymmetric density perturbation that is produced in the disk, as response to the presence of the binary. Using SPH numerical simulations we tested two gap-opening criterion, one that assumes that the geometry of the density perturbation is an ellipsoid/thick-spirals and another that assumes a geometry of flat-spirals for the density perturbation. We find that the flat-spirals gap opening criterion successfully predicts which simulations will hav...

  8. Binaries migrating in a gaseous disk: Where are the Galactic center binaries?

    CERN Document Server

    Baruteau, C; Lin, D N C

    2010-01-01

    The massive stars in the Galactic center inner arcsecond share analogous properties with the so-called Hot Jupiters. Most of these young stars have highly eccentric orbits, and were probably not formed in-situ. It has been proposed that these stars acquired their current orbits from the tidal disruption of compact massive binaries scattered toward the proximity of the central supermassive black hole. Assuming a binary star formed in a thin gaseous disk beyond 0.1 pc from the central object, we investigate the relevance of disk-satellite interactions to harden the binding energy of the binary, and to drive its inward migration. A massive, equal-mass binary star is found to become more tightly wound as it migrates inwards toward the central black hole. The migration timescale is very similar to that of a single-star satellite of the same mass. The binary's hardening is caused by the formation of spiral tails lagging the stars inside the binary's Hill radius. We show that the hardening timescale is mostly determ...

  9. RGD偶联吉西他滨白蛋白纳米粒对胰腺癌细胞增殖抑制作用的研究%Study on inhibitory effects of RGD-conjugated gemcitabine-loaded albumin nanoparticles on the proliferation of BxPC-3 cells in vitro

    Institute of Scientific and Technical Information of China (English)

    吉顺荣; 吴闻哲; 王浩; 张波; 刘辰; 龙江; 虞先濬; 倪泉兴; 徐近

    2011-01-01

    Objective To explore the inhibitory effects of RGD-conjugated gemcitabine (GEM)-loaded albumin nanoparticles (ANP) on the proliferation of BxPC-3 cells in vitro. Methods Human pancreatic carcinoma BxPC-3 cells were cultured and then treated 5 different combinations of drugs (BSANP controls, RGD-BSANP, BSANP-GEM, GEM and RGD-BSANP-GEM) respectively. The inhibition rate of BxPC-3 cells was detected by MTT. Results The gemcitabine-loaded albumin nanoparticles produced higher inhibitory effects than gemcitabine alone. The RGD-conjugated gemcitabine-loaded albumin nanoparticles produced even higher anti-proliferation rate than those without RGD conjugation. Conclusions RGD peptides can increase the anti-proliferation rate of gemcitabine-loaded albumin nanoparticles on BxPC-3 cells in vitro.%目的:通过体外试验,探讨RGD偶联吉西他滨白蛋白纳米粒(RGD-BSANP-GEM)对胰腺癌细胞株BxPC-3的体外增殖的抑制作用.方法:以人胰腺癌细胞株BxPC-3为研究对象,分为5个给药组:BSANP对照组、RGD-BSANP组、BSANP-GEM组、GEM原药组、RGD-BSANP-GEM组.运用MTT法检测给药后24h、48 h和72 h的增殖抑制率.结果:BSANP-GEM组细胞抑制率高于GEM组(P<0.05),RGD-BSANP-GEM组细胞抑制率高于BSANP-GEM组.同时RGD-BSANP-GEM组对胰腺癌细胞株的抑制率与给药浓度和作用时间呈正相关.结论:体外RGD环肽能够增加BSANP-GEM对胰腺癌细胞的增殖抑制作用.

  10. B掺杂对LiFeP1-xBxO4-δ/C电化学性能的影响%The Effect of B-doping on the Electrochemical Properties of LiFeP1-xBxO4-δ/C Cathode Materials

    Institute of Scientific and Technical Information of China (English)

    刘花; 任兆刚

    2013-01-01

    On the basis of the analysis of doping in the P-site,B-doped in P-site,LiFeP1-xBxO4-δ/C (x =0,0.025,0.05,0.075) composite materials were synthesized in flowing Ar atmosphere by sol-gel method,with citric acid as chelating agent and carbon source.The electrochemical performances of samples were characterized by cyclic voltammetry and galvanostatic charge/discharge tests in terms of cycling performance and rate capability.The results show that B-doping improves the conductivity of composite materials; decreases the polarization of electrode,and enhances the cycling performance and rate capability effectively.The discharge capacities of LiFeP0.95 B0.05 O4-δ/C are 149.3mAh · g-1 at 0.2C,with retention ration of 99.3% after 20 cycles.After continuous 30 cycles at different rates of 0.2C,1C,3C,5Cand 10C,the discharge capacity at 0.2C can reconvert to the previous value.%采用溶胶凝胶法结合高温固相反应合成B在P位掺杂的LiFeP1-xBxO4-/C(x=0,0.025,0.05,0.075)复合材料,通过循环伏安、恒流充放电测试等手段研究B掺杂对复合材料电化学性能的影响.结果表明,B在P位掺杂可降低材料极化,有利于改善材料的循环性能和倍率性能,最优掺杂量为5% mol.LiFeP0.95B0.05O4-δ/C0.2C的首次放电比容量为149.3 mAh · g-1,容量保持率为99.3%(20次),不同倍率下持续充放电30次后,0.2C放电容量仍能恢复.

  11. White-light Flares on Close Binaries Observed with Kepler

    Science.gov (United States)

    Gao, Qing; Xin, Yu; Liu, Ji-Feng; Zhang, Xiao-Bin; Gao, Shuang

    2016-06-01

    Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies (“detachedness”). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%–20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P orb) and rotation period (P rot, calculated for only detached binaries). We find that the AL increases with decreasing P orb or P rot, up to the critical values at P orb ∼ 3 days or P rot ∼ 1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.

  12. Binary interaction dominates the evolution of massive stars

    CERN Document Server

    Sana, H; de Koter, A; Langer, N; Evans, C J; Gieles, M; Gosset, E; Izzard, R G; Bouquin, J -B Le; Schneider, F R N; 10.1126/science.1223344

    2012-01-01

    The presence of a nearby companion alters the evolution of massive stars in binary systems, leading to phenomena such as stellar mergers, X-ray binaries and gamma-ray bursts. Unambiguous constraints on the fraction of massive stars affected by binary interaction were lacking. We simultaneously measured all relevant binary characteristics in a sample of Galactic massive O stars and quantified the frequency and nature of binary interactions. Over seventy per cent of all massive stars will exchange mass with a companion, leading to a binary merger in one third of the cases. These numbers greatly exceed previous estimates and imply that binary interaction dominates the evolution of massive stars, with implications for populations of massive stars and their supernovae.

  13. Twin Binaries: Studies of Stability, Mass Transfer, and Coalescence

    CERN Document Server

    Lombardi, James C; Dooley, Katherine L; Gearity, Kyle; Kalogera, Vassiliki; Rasio, Frederic A

    2010-01-01

    Motivated by suggestions that binaries with almost equal-mass components ("twins") play an important role in the formation of double neutron stars and may be rather abundant among binaries, we study the stability of synchronized close and contact binaries with identical components in circular orbits. In particular, we investigate the dependency of the innermost stable circular orbit on the core mass, and we study the coalescence of the binary that occurs at smaller separations. For twin binaries composed of convective main-sequence stars, subgiants, or giants with low mass cores (M_c ~0.15M), we find that stable contact configurations exist at all separations down to the Roche limit, when mass shedding through the outer Lagrangian points triggers a coalescence of the envelopes and leaves the cores orbiting in a central tight binary. We discuss the implications of our results to the formation of binary neutron stars.

  14. 1974: the discovery of the first binary pulsar

    CERN Document Server

    Damour, Thibault

    2014-01-01

    The 1974 discovery, by Russell A. Hulse and Joseph H. Taylor, of the first binary pulsar PSR 1913+16, opened up new possibilities for the study of relativistic gravity. PSR 1913+16, as well as several other binary pulsars, provided {\\it direct} observational proofs that gravity propagates at the velocity of light and has a quadrupolar structure. Binary pulsars also provided accurate tests of the strong-field regime of relativistic gravity. General Relativity has passed all the binary pulsar tests with flying colors. The discovery of binary pulsars had also very important consequences for astrophysics: accurate measurement of neutron star masses, improved understanding of the possible evolution scenarios for the co-evolution of binary stars, proof of the existence of binary neutron stars emitting gravitational waves for hundreds of millions of years, before coalescing in catastrophic events probably leading to an important emission of electromagnetic radiation and neutrinos. This article reviews the history of...

  15. Performance analysis and binary working fluid selection of combined flash-binary geothermal cycle

    International Nuclear Information System (INIS)

    Performance of the combined flash-binary geothermal power cycle for geofluid temperatures between 150 and 250 °C is studied. A thermodynamic model is developed, and the suitable binary working fluids for different geofluid temperatures are identified from a list of thirty working fluid candidates, consisting environmental friendly refrigerants and hydrocarbons. The overall system exergy destruction and Vapor Expansion Ratio across the binary cycle turbine are selected as key performance indicators. The results show that for low-temperature heat sources using refrigerants as binary working fluids result in higher overall cycle efficiency and for medium and high-temperature resources, hydrocarbons are more suitable. For combined flash-binary cycle, secondary working fluids; R-152a, Butane and Cis-butane show the best performances at geofluid temperatures 150, 200 and 250 °C respectively. The overall second law efficiency is calculated as high as 0.48, 0.55 and 0.58 for geofluid temperatures equal 150, 200 and 250 °C respectively. The flash separator pressure found to has important effects on cycle operation and performance. Separator pressure dictates the work production share of steam and binary parts of the system. And there is an optimal separator pressure at which overall exergy destruction of the cycle achieves its minimum value. - Highlights: • Performance of the combined flash-binary geothermal cycle is investigated. • Thirty different fluids are screened to find the most suitable ORC working fluid. • Optimum cycle operation conditions presented for geofluids between 150 °C and 250 °C. • Refrigerants are more suitable for the ORC at geothermal sources temperature ≤200 °C. • Hydrocarbons are more suitable for the ORC at geothermal sources temperature >200 °C

  16. Evolution of Close Neutron Star Binaries

    CERN Document Server

    Ogawaguchi, W

    1996-01-01

    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.

  17. A Binary Representation of the Genetic Code

    CERN Document Server

    Nemzer, Louis R

    2016-01-01

    This article introduces a novel binary representation of the canonical genetic code, in which each of the four mRNA nucleotide bases is assigned a unique 2-bit identifier. These designations have a physiological meaning derived from the molecular structures of, and relationships between, the bases. In this scheme, the 64 possible triplet codons are each indexed by a 6-bit label. The order of the bits reflects the hierarchical organization manifested by the DNA replication/repair and tRNA translation systems. Transition and transversion mutations are naturally expressed as basic binary operations, and the severity of the different types is analyzed. Using a principal component analysis, it is shown that physicochemical properties of amino acids related to protein folding also correlate with particular bit positions of their respective labels. Thus, the likelihood for a particular point mutation to be conservative, and therefore less likely to cause a change in protein functionality, can be estimated.

  18. Hamiltonian Hydrodynamics and Irrotational Binary Inspiral

    CERN Document Server

    Markakis, Charalampos M

    2014-01-01

    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 ...

  19. Toroidal Horizons in Binary Black Hole Mergers

    CERN Document Server

    Bohn, Andy; Teukolsky, Saul A

    2016-01-01

    We find the first binary black hole event horizon with a toroidal topology. It had been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology, but such a phase has never been seen prior to this work. In all previous binary black hole simulations, in the coordinate slicing used to evolve the black holes, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. We present a coordinate transformation to a foliation of spacelike hypersurfaces that "cut a hole" through the event horizon surface, resulting in a toroidal event horizon. A torus could potentially provide a mechanism for violating topological censorship. However, these toroidal event horizons satisfy topological censorship by construction, because we can always trivially apply the inverse coordinate transformation to remove the topological feature.

  20. Construction of generalized binary Bent sequences

    Institute of Scientific and Technical Information of China (English)

    KE Pin-hui; CHANG Zu-ling; WEN Qiao-yan

    2006-01-01

    Bent functions in trace forms play an important role in the constructions of generalized binary Bent sequences.Trace representation of some degree two Bent functions are presented in this paper.A sufficient and necessary condition is derived to determine whether the sum of the combinations of Gold functions,tr1n(x2'+1),1≤I≤n-1,over finite fields F2n (n be even) in addition to another term tr1n/2(x2n/2+1) is a Bent function.Similar to the result presented by Khoo et al.,the condition can be verified by polynominal greatest common divisor (GCD) computation.A similar result also holds in the case Fpn (n be even,p be odd prime).Using the constructed Bent functions and Niho type Bent functions given by Dobbertin et al.,many new generalized binary Bent sequences are obtained.

  1. Binary hidden Markov models and varieties

    CERN Document Server

    Critch, Andrew J

    2012-01-01

    The technological applications of hidden Markov models have been extremely diverse and successful, including natural language processing, gesture recognition, gene sequencing, and Kalman filtering of physical measurements. HMMs are highly non-linear statistical models, and just as linear models are amenable to linear algebraic techniques, non-linear models are amenable to commutative algebra and algebraic geometry. This paper examines closely those HMMs in which all the random variables, called nodes, are binary. Its main contributions are (1) minimal defining equations for the 4-node model, comprising 21 quadrics and 29 cubics, which were computed using Gr\\"obner bases in the cumulant coordinates of Sturmfels and Zwiernik, and (2) a birational parametrization for every binary HMM, with an explicit inverse for recovering the hidden parameters in terms of observables. The new model parameters in (2) are hence rationally identifiable in the sense of Sullivant, Garcia-Puente, and Spielvogel, and each model's Zar...

  2. Dynamics and Habitability in Binary Star Systems

    CERN Document Server

    Eggl, Siegfried; Pilat-Lohinger, Elke

    2014-01-01

    Determining planetary habitability is a complex matter, as the interplay between a planet's physical and atmospheric properties with stellar insolation has to be studied in a self consistent manner. Standardized atmospheric models for Earth-like planets exist and are commonly accepted as a reference for estimates of Habitable Zones. In order to define Habitable Zone boundaries, circular orbital configurations around main sequence stars are generally assumed. In gravitationally interacting multibody systems, such as double stars, however, planetary orbits are forcibly becoming non circular with time. Especially in binary star systems even relatively small changes in a planet's orbit can have a large impact on habitability. Hence, we argue that a minimum model for calculating Habitable Zones in binary star systems has to include dynamical interactions.

  3. Binary Fingerprints at Fluctuation-Enhanced Sensing

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    We developed a simple way to generate binary patterns based on spectral slopes in different frequency ranges at fluctuation-enhanced sensing. Such patterns can be considered as binary "fingerprints" of odors. The method has experimentally been demonstrated with a commercial semiconducting metal oxide (Taguchi) sensor exposed to bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) and processing their stochastic signals. With a single Taguchi sensor, the situations of empty chamber, tryptic soy agar (TSA) medium, or TSA with bacteria could be distinguished with 100% reproducibility. The bacterium numbers were in the range of 25 thousands to 1 million. To illustrate the relevance for ultra-low power consumption, we show that this new type of signal processing and pattern recognition task can be implemented by a simple analog circuitry and a few logic gates with total power consumption in the microWatts range.

  4. Complex Binary Number System Algorithms and Circuits

    CERN Document Server

    Jamil, Tariq

    2013-01-01

    This book is a compilation of the entire research work on the topic of Complex Binary Number System (CBNS) carried out by the author as the principal investigator and members of his research groups at various universities during the years 1992-2012. Pursuant to these efforts spanning several years, the realization of CBNS as a viable alternative to represent complex numbers in an 'all-in-one' binary number format has become possible and efforts are underway to build computer hardware based on this unique number system. It is hoped that this work will be of interest to anyone involved in computer arithmetic and digital logic design and kindle renewed enthusiasm among the engineers working in the areas of digital signal and image processing for developing newer and efficient algorithms and techniques incorporating CBNS.

  5. Cosmic ray acceleration by binary neutron stars

    Science.gov (United States)

    Kundt, W.

    Young binary neutron stars, the elder brothers of pulsars, are proposed as the boosters of the ionic component of cosmic rays. Their rotational energy can be converted into beams of cosmic rays if there is enough coupling between the corotating magnetosphere and the impinging plasma, in a manner similar to the sparking of a grindstone. Power-law spectra in energy are obtained from a power-law dependence of the accelerating fields. The upper cutoff energy should not greatly exceed 10 to the 20th eV. The observed ionic cosmic-ray spectrum would result from a superposition of the injection by no more than about one million young binary neutron stars.

  6. Sequential binary decay of highly excited nuclei

    International Nuclear Information System (INIS)

    The decay of highly excited nuclei is described as a sequence of binary processes involving emission of fragments in their ground, excited-bound and unbound states. Primary together with secondary decay products lead to the final mass distributions. Asymmetric mass splittings involving nucleon emission up to symmetric binary ones are treated according to a generalized Weisskopf evaporation formalism. This procedure is implemented in the Monte-Carlo multi-step statistical model code MECO (Multisequential Evaporation COde). We examine the evolution of the calculated final mass distributions in the decay of a light compound nucleus, as the initial excitation energy increases towards the limits of complete dissociation. Comparisons are made with the predictions of the transition-stage theory, as well as a consistent Weisskopf treatment in which the decay process is described by rate equations for the generation of different fragment species. (author)

  7. Superconducting State Parameters of Binary Superconductors

    Directory of Open Access Journals (Sweden)

    Aditya M. Vora

    2012-05-01

    Full Text Available A well known pseudopotential is used to investigate the superconducting state parameters viz. electron-phonon coupling strength , Coulomb pseudopotential *, transition temperature ТС, isotope effect exponent  and effective interaction strength N0V for the AgxZn1 – x and AgxAl1 – x binary superconductors theoretically for the first time. We have incorporated here five different types of the local field correction functions to show the effect of exchange and correlation on the aforesaid properties. Very strong influence of the various exchange and correlation functions is concluded from the present study. The comparison with other such experimental values is encouraging, which confirms the applicability of the model potential in explaining the superconducting state parameters of binary mixture.

  8. BISC: binary subcomplexes in proteins database.

    Science.gov (United States)

    Juettemann, Thomas; Gerloff, Dietlind L

    2011-01-01

    Binary subcomplexes in proteins database (BISC) is a new protein-protein interaction (PPI) database linking up the two communities most active in their characterization: structural biology and functional genomics researchers. The BISC resource offers users (i) a structural perspective and related information about binary subcomplexes (i.e. physical direct interactions between proteins) that are either structurally characterized or modellable entries in the main functional genomics PPI databases BioGRID, IntAct and HPRD; (ii) selected web services to further investigate the validity of postulated PPI by inspection of their hypothetical modelled interfaces. Among other uses we envision that this resource can help identify possible false positive PPI in current database records. BISC is freely available at http://bisc.cse.ucsc.edu. PMID:21081561

  9. General Properties of Near-Contact Binaries

    Science.gov (United States)

    Oh, Kyu-Dong; Kim, Ho-Il; Kang, Young-Woon; Lee, Woo-Baik

    2000-12-01

    The general properties of the NCBs, divided into A and F types according to their spectral types, have been presented. The evolutionary status of the F type near-contact binaries are closer to that of the contact systems, i.e., W UMa type binaries, if it is assumed that the evolution of the NCBs is governed by the thermal relaxation oscillation theory. The mass-radius relation, mass-luminosity relation and H-R diagram of the NCBs provide that the A type NCBs suffer from more active mass transfer than F types. The components of the NCBs are still in main-sequence like W UMa type stars and their two components lines parallel to the ZAMS.

  10. Stellivore extraterrestrials? Binary stars as living systems

    Science.gov (United States)

    Vidal, Clément

    2016-11-01

    We lack signs of extraterrestrial intelligence (ETI) despite decades of observation in the whole electromagnetic spectrum. Could evidence be buried in existing data? To recognize ETI, we first propose criteria discerning life from non-life based on thermodynamics and living systems theory. Then we extrapolate civilizational development to both external and internal growth. Taken together, these two trends lead to an argument that some existing binary stars might actually be ETI. Since these hypothetical beings feed actively on stars, we call them "stellivores". I present an independent thermodynamic argument for their existence, with a metabolic interpretation of interacting binary stars. The jury is still out, but the hypothesis is empirically testable with existing astrophysical data.

  11. Binary Minor Planets V9.0

    Science.gov (United States)

    Johnston, W. R.

    2016-07-01

    The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, compiled from the published literature as inspired by Richardson and Walsh (2006) and similar reviews (Merline et al., 2003; Noll, 2006; Pravec et al., 2006; Pravec and Harris, 2007; Descamps and Marchis, 2008; Noll et al., 2008; Walsh, 2009). In total 297 companions in 282 systems are included. Data are presented in three tables: one for orbital and physical properties; one for companion designations, discovery information, and reference codes for data values; and one giving full references for each reference code. This data set is complete for binary/multiple components reported through 31 March 2016.

  12. Buffer Overflow Detection on Binary Code

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yan-fei; LI Hui; CHEN Ke-fei

    2006-01-01

    Most solutions for detecting buffer overflow are based on source code. But the requirement for source code is not always practical especially for business software. A new approach was presented to detect statically the potential buffer overflow vulnerabilities in the binary code of software. The binary code was translated into assembly code without the lose of the information of string operation functions. The feature code abstract graph was constructed to generate more accurate constraint statements, and analyze the assembly code using the method of integer range constraint. After getting the elementary report on suspicious code where buffer overflows possibly happen, the control flow sensitive analysis using program dependence graph was done to decrease the rate of false positive. A prototype was implemented which demonstrates the feasibility and efficiency of the new approach.

  13. Eclipsing binary stars modeling and analysis

    CERN Document Server

    Kallrath, Josef

    1999-01-01

    This book focuses on the formulation of mathematical models for the light curves of eclipsing binary stars, and on the algorithms for generating such models Since information gained from binary systems provides much of what we know of the masses, luminosities, and radii of stars, such models are acquiring increasing importance in studies of stellar structure and evolution As in other areas of science, the computer revolution has given many astronomers tools that previously only specialists could use; anyone with access to a set of data can now expect to be able to model it This book will provide astronomers, both amateur and professional, with a guide for - specifying an astrophysical model for a set of observations - selecting an algorithm to determine the parameters of the model - estimating the errors of the parameters It is written for readers with knowledge of basic calculus and linear algebra; appendices cover mathematical details on such matters as optimization, coordinate systems, and specific models ...

  14. Coalescence of Magnetized Binary Neutron Star Systems

    Science.gov (United States)

    Motl, Patrick M.; Anderson, Matthew; Lehner, Luis; Liebling, Steven L.; Neilsen, David; Palenzuela, Carlos; Ponce, Marcelo

    2015-01-01

    We present simulations of the merger of binary neutron star systems calculated with full general relativity and incorporating the global magnetic field structure for the stars evolved with resistive magnetohydrodynamics. Our simulation tools have recently been improved to incorporate the effects of neutrino cooling and have been generalized to allow for tabular equations of state to describe the degenerate matter. Of particular interest are possible electromagnetic counterparts to the gravitational radiation that emerges from these systems. We focus on magnetospheric interactions that ultimately tap into the gravitational potential energy of the binary to power a Poynting flux and deposition of energy through Joule heating and magnetic reconnection. We gratefully acknowledge the support of NASA through the Astrophysics Theory Program grant NNX13AH01G.

  15. Simulation of nuclei morphologies for binary alloy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We study the critical nuclei morphologies of a binary alloy by the string method. The dynamic equation of the string, connecting the metastable phase (liquid) and stable phase (solid), is governed by Helmholtz free energy for the binary alloy system at a given temperature. The stationary string through the critical nucleus (saddle point) is obtained if the relaxation time of the string is su?ciently large. The critical nucleus radius and energy barrier to nucleation of a pure alloy with isotropic interface energy in two and three dimensions are calculated, which are consistent with the classical nucleation theory. The critical nuclei morphologies are sensitive to the anisotropy strength of interface energy and interface thickness of alloy in two and three dimensions. The critical nucleus and energy barrier to nucleation become smaller if the anisotropy strength of the interface energy is increased, which means that it is much easier to form a stable nucleus if the anisotropy of the interface energy is considered.

  16. Processes assessment in binary mixture plant

    Directory of Open Access Journals (Sweden)

    N. Shankar Ganesh, T. Srinivas

    2013-01-01

    Full Text Available Binary fluid system has an efficient system of heat recovery compared to a single fluid system due to a better temperature match between hot and cold fluids. There are many applications with binary fluid system i.e. Kalina power generation, vapor absorption refrigeration, combined power and cooling etc. Due to involvement of three properties (pressure, temperature and concentration in the processes evaluation, the solution is complicated compared to a pure substance. The current work simplifies this complex nature of solution and analyzes the basic processes to understand the processes behavior in power generation as well as cooling plants. Kalina power plant consists of regenerator, heat recovery vapor generator, condenser, mixture, separator, turbine, pump and throttling device. In addition to some of these components, the cooling plant consists of absorber which is similar in operation of condenser. The amount of vapor at the separator decreases with an increase in its pressure and temperature.

  17. Parallel Matrix Factorization for Binary Response

    CERN Document Server

    Khanna, Rajiv; Agarwal, Deepak; Chen, Beechung

    2012-01-01

    Predicting user affinity to items is an important problem in applications like content optimization, computational advertising, and many more. While bilinear random effect models (matrix factorization) provide state-of-the-art performance when minimizing RMSE through a Gaussian response model on explicit ratings data, applying it to imbalanced binary response data presents additional challenges that we carefully study in this paper. Data in many applications usually consist of users' implicit response that are often binary -- clicking an item or not; the goal is to predict click rates, which is often combined with other measures to calculate utilities to rank items at runtime of the recommender systems. Because of the implicit nature, such data are usually much larger than explicit rating data and often have an imbalanced distribution with a small fraction of click events, making accurate click rate prediction difficult. In this paper, we address two problems. First, we show previous techniques to estimate bi...

  18. Kepler Eclipsing Binary Stars. V. Identification of 31 Eclipsing Binaries in the K2 Engineering Data-set

    CERN Document Server

    Conroy, Kyle E; Stassun, Keivan G; Bloemen, Steven; Parvizi, Mahmoud; Quarles, Billy; Boyajian, Tabetha; Barclay, Thomas; Shporer, Avi; Latham, David W; Abdul-Masih, Michael

    2014-01-01

    Over 2500 eclipsing binaries were identified and characterized from the ultra-precise photometric data provided by the Kepler space telescope. Kepler is now beginning its second mission, K2, which is proving to again provide ultra-precise photometry for a large sample of eclipsing binary stars. In the 1951 light curves covering 12 days in the K2 engineering data-set, we have identified and determined the ephemerides for 31 eclipsing binaries that demonstrate the capabilities for eclipsing binary science in the upcoming campaigns in K2. Of those, 20 are new discoveries. We describe both manual and automated approaches to harvesting the complete set of eclipsing binaries in the K2 data, provide identifications and details for the full set of eclipsing binaries present in the engineering data-set, and discuss the prospects for application of eclipsing binary searches in the K2 mission.

  19. Gravity Waves, Chaos, and Spinning Compact Binaries

    OpenAIRE

    Levin, Janna

    1999-01-01

    Spinning compact binaries are shown to be chaotic in the Post-Newtonian expansion of the two body system. Chaos by definition is the extreme sensitivity to initial conditions and a consequent inability to predict the outcome of the evolution. As a result, the spinning pair will have unpredictable gravitational waveforms during coalescence. This poses a challenge to future gravity wave observatories which rely on a match between the data and a theoretical template.

  20. Dynamics of phase separation of binary fluids

    Science.gov (United States)

    Ma, Wen-Jong; Maritan, Amos; Banavar, Jayanth R.; Koplik, Joel

    1992-01-01

    The results of molecular-dynamics studies of surface-tension-dominated spinodal decomposition of initially well-mixed binary fluids in the absence and presence of gravity are presented. The growth exponent for the domain size and the decay exponent of the potential energy of interaction between the two species with time are found to be 0.6 +/- 0.1, inconsistent with scaling arguments based on dimensional analysis.

  1. Automated pupil remapping with binary optics

    Science.gov (United States)

    Neal, Daniel R.; Mansell, Justin

    1999-01-01

    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.

  2. Gravitational waves from binary black holes

    Indian Academy of Sciences (India)

    Bala R Iyer

    2011-07-01

    It is almost a century since Einstein predicted the existence of gravitational waves as one of the consequences of his general theory of relativity. A brief historical overview including Chandrasekhar’s contribution to the subject is first presented. The current status of the experimental search for gravitational waves and the attendant theoretical insights into the two-body problem in general relativity arising from computations of gravitational waves from binary black holes are then broadly reviewed.

  3. Modified Sonine approximation for granular binary mixtures

    OpenAIRE

    Garzó, Vicente; Reyes, Francisco Vega; Montanero, José María

    2008-01-01

    We evaluate in this work the hydrodynamic transport coefficients of a granular binary mixture in $d$ dimensions. In order to eliminate the observed disagreement (for strong dissipation) between computer simulations and previously calculated theoretical transport coefficients for a monocomponent gas, we obtain explicit expressions of the seven Navier-Stokes transport coefficients with the use of a new Sonine approach in the Chapman-Enskog theory. Our new approach consists in replacing, where a...

  4. Minimum degree and density of binary sequences

    DEFF Research Database (Denmark)

    Brandt, Stephan; Müttel, J.; Rautenbach, D.;

    2010-01-01

    For d,k∈N with k ≤ 2d, let g(d,k) denote the infimum density of binary sequences (x)∈{0,1} which satisfy the minimum degree condition σ(x+) ≥ k for all i∈Z with xi=1. We reduce the problem of computing g(d,k) to a combinatorial problem related to the generalized k-girth of a graph G which is defi...

  5. Modeling Flows Around Merging Black Hole Binaries

    OpenAIRE

    van Meter, James R.; Wise, John H.; Miller, M. Coleman; Reynolds, Christopher S.; Centrella, Joan M.; Baker, John G.; Boggs, William D.; Kelly, Bernard J.; McWilliams, Sean T.

    2009-01-01

    Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the stron...

  6. Binary outcome variables and logistic regression models

    Institute of Scientific and Technical Information of China (English)

    Xinhua LIU

    2011-01-01

    Biomedical researchers often study binary variables that indicate whether or not a specific event,such as remission of depression symptoms,occurs during the study period.The indicator variable Y takes two values,usually coded as one if the event (remission) is present and zero if the event is not present(non-remission).Let p be the probability that the event occurs ( Y =1),then 1-p will be the probability that the event does not occur ( Y =0).

  7. Binary dicots, a core of dicot games

    OpenAIRE

    Renault, Gabriel

    2014-01-01

    We study combinatorial games under mis\\`ere convention. Several sets of games have been considered earlier to better understand the behaviour of mis\\`ere games. We here connect several of these sets. In particular, we prove that comparison modulo binary dicot games is often the same as comparison modulo dicot games, and that equivalence modulo dicot games and modulo impartial games are the same when they are restricted to impartial games.

  8. Binary Schemes of Vapor Bubble Growth

    Science.gov (United States)

    Zudin, Yu. B.

    2015-05-01

    A problem on spherically symmetric growth of a vapor bubble in an infi nite volume of a uniformly superheated liquid is considered. A description of the limiting schemes of bubble growth is presented. A binary inertial-thermal bubble growth scheme characterized by such specifi c features as the "three quarters" growth law and the effect of "pressure blocking" in a vapor phase is considered.

  9. Binary progenitor models of type IIb supernovae

    CERN Document Server

    Claeys, J S W; Pols, O R; Eldridge, J J; Baes, M

    2011-01-01

    Massive stars that lose their hydrogen-rich envelope down to a few tenths of a solar mass explode as extended type IIb supernovae, an intriguing subtype that links the hydrogen-rich type II supernovae with the hydrogen-poor type Ib and Ic. The progenitors may be very massive single stars that lose their envelope due to their stellar wind, but mass stripping due to interaction with a companion star in a binary system is currently considered to be the dominant formation channel. We computed an extensive grid of binary models with the Eggleton binary evolution code. The predicted rate from our standard models, which assume conservative mass transfer, is about 6 times smaller than the current rate indicated by observations. It is larger but still comparable to the rate expected from single stars. To recover the observed rate we must generously allow for uncertainties and low accretion efficiencies in combination with limited angular momentum loss from the system. Motivated by the claims of detection and non-detec...

  10. A radio pulsing white dwarf binary star

    CERN Document Server

    Marsh, T R; Hümmerich, S; Hambsch, F -J; Bernhard, K; Lloyd, C; Breedt, E; Stanway, E R; Steeghs, D T; Parsons, S G; Toloza, O; Schreiber, M R; Jonker, P G; van Roestel, J; Kupfer, T; Pala, A F; Dhillon, V S; Hardy, L K; Littlefair, S P; Aungwerojwit, A; Arjyotha, S; Koester, D; Bochinski, J J; Haswell, C A; Frank, P; Wheatley, P J

    2016-01-01

    White dwarfs are compact stars, similar in size to Earth but ~200,000 times more massive. Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the resulting mass transfer can generate atomic line and X-ray emission, as well as near- and mid-infrared radiation if the white dwarf is magnetic. However, even in binaries, white dwarfs are rarely detected at far-infrared or radio frequencies. Here we report the discovery of a white dwarf / cool star binary that emits from X-ray to radio wavelengths. The star, AR Scorpii (henceforth AR Sco), was classified in the early 1970s as a delta-Scuti star, a common variety of periodic variable star. Our observations reveal instead a 3.56 hr period close binary, pulsing in brightness on a period of 1.97 min. The pulses are so intense that AR Sco's optical flux can increase by a factor of four within 30 s, and they are detectable a...

  11. Spinodal decomposition of chemically reactive binary mixtures

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration.

  12. Outbursts in ultracompact X-ray binaries

    CERN Document Server

    Hameury, J -M

    2016-01-01

    Very faint X-ray binaries appear to be transient in many cases with peak luminosities much fainter than that of usual soft X-ray transients, but their nature still remains elusive. We investigate the possibility that this transient behaviour is due to the same thermal/viscous instability which is responsible for outbursts of bright soft X-ray transients, occurring in ultracompact binaries for adequately low mass-transfer rates. More generally, we investigate the observational consequences of this instability when it occurs in ultracompact binaries. We use our code for modelling the thermal-viscous instability of the accretion disc, assumed here to be hydrogen poor. We also take into account the effects of disc X-ray irradiation, and consider the impact of the mass-transfer rate on the outburst brightness. We find that one can reproduce the observed properties of both the very faint and the brighter short transients (peak luminosity, duration, recurrence times), provided that the viscosity parameter in quiesce...

  13. Spinodal decomposition of chemically reactive binary mixtures.

    Science.gov (United States)

    Lamorgese, A; Mauri, R

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration. PMID:27627358

  14. Modeling selective intergranular oxidation of binary alloys

    Science.gov (United States)

    Xu, Zhijie; Li, Dongsheng; Schreiber, Daniel K.; Rosso, Kevin M.; Bruemmer, Stephen M.

    2015-01-01

    Intergranular attack of alloys under hydrothermal conditions is a complex problem that depends on metal and oxygen transport kinetics via solid-state and channel-like pathways to an advancing oxidation front. Experiments reveal very different rates of intergranular attack and minor element depletion distances ahead of the oxidation front for nickel-based binary alloys depending on the minor element. For example, a significant Cr depletion up to 9 μm ahead of grain boundary crack tips was documented for Ni-5Cr binary alloy, in contrast to relatively moderate Al depletion for Ni-5Al (˜100 s of nm). We present a mathematical kinetics model that adapts Wagner's model for thick film growth to intergranular attack of binary alloys. The transport coefficients of elements O, Ni, Cr, and Al in bulk alloys and along grain boundaries were estimated from the literature. For planar surface oxidation, a critical concentration of the minor element can be determined from the model where the oxide of minor element becomes dominant over the major element. This generic model for simple grain boundary oxidation can predict oxidation penetration velocities and minor element depletion distances ahead of the advancing front that are comparable to experimental data. The significant distance of depletion of Cr in Ni-5Cr in contrast to the localized Al depletion in Ni-5Al can be explained by the model due to the combination of the relatively faster diffusion of Cr along the grain boundary and slower diffusion in bulk grains, relative to Al.

  15. Circumstellar disks around binary stars in Taurus

    Energy Technology Data Exchange (ETDEWEB)

    Akeson, R. L. [NASA Exoplanet Science Institute, IPAC/Caltech, Pasadena, CA 91125 (United States); Jensen, E. L. N. [Swarthmore College, Department of Physics and Astronomy, Swarthmore, PA 19081 (United States)

    2014-03-20

    We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10{sup –4} M {sub ☉}. We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F{sub mm}∝M{sub ∗}{sup 1.5--2.0} to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

  16. Observational Signatures of Binary Supermassive Black Holes

    CERN Document Server

    Roedig, Constanze; Miller, M Coleman

    2014-01-01

    Observations indicate that most massive galaxies contain a supermassive black hole, and theoretical studies suggest that when such galaxies have a major merger, the central black holes will form a binary and eventually coalesce. Here we discuss two spectral signatures of such binaries that may help distinguish them from ordinary AGN. These signatures are expected when the mass ratio between the holes is not extreme and the system is fed by a circumbinary disk. One such signature is a notch in the thermal continuum that has been predicted by other authors; we point out that it should be accompanied by a spectral revival at shorter wavelengths and also discuss its dependence on binary properties such as mass, mass ratio, and separation. In particular, we note that the wavelength $\\lambda_n$ at which the notch occurs depends on these three parameters in such a way as to make the number of systems displaying these notches $\\propto \\lambda_n^{16/3}$; longer wavelength searches are therefore strongly favored. A sec...

  17. On the Component Masses of Visual Binaries

    Directory of Open Access Journals (Sweden)

    Ninkovic, S.

    2010-06-01

    Full Text Available In the Sixth Catalog of Orbits of Visual Binary Stars we found those belonging to the Main Sequence to form a sample containing 432 visual binaries. Their total masses were obtained dynamically, i.e. they were calculated using the orbital elements and the new Hipparcos parallaxes. For the same pairs the total mass was also found astrophysically - by applying the mass-luminosity relation. The apparent magnitudes of the components were found in two different ways: by deriving them from total magnitudes and magnitude differences, and by taking their values directly from a catalogue. The results for these two approaches show no essential discrepancy. The values of total masses obtained dynamically have a large dispersion involving even completely unrealistic values. This is a clear indication that the input data are not sufficiently reliable. Nevertheless, in a large number of cases the agreement between total masses obtained by usin two different ways is quite satisfactory indicating that i for many visual binaries, as a rule not too distant and with high-quality orbital elements, the dynamical total masses can be reliable; ii the mass-luminosity relation yields quite satisfactory estimates for the component masses when they belong to the Main Sequence and iii a correlation between the relative parallax error and orbit grade exists.

  18. A Gray path on binary partitions

    CERN Document Server

    Colthurst, Thomas

    2009-01-01

    A binary partition of a positive integer $n$ is a partition of $n$ in which each part has size a power of two. In this note we first construct a Gray sequence on the set of binary partitions of $n$. This is an ordering of the set of binary partitions of each $n$ (or of all $n$) such that adjacent partitions differ by one of a small set of elementary transformations; here the allowed transformatios are replacing $2^k+2^k$ by $2^{k+1}$ or vice versa (or addition of a new +1). Next we give a purely local condition for finding the successor of any partition in this sequence; the rule is so simple that successive transitions can be performed in constant time. Finally we show how to compute directly the bijection between $k$ and the $k$th term in the sequence. This answers a question posed by Donald Knuth in section 7.2.1 of The Art of Computer Programming.

  19. Brown Dwarf Binaries from Disintegrating Triple Systems

    CERN Document Server

    Reipurth, Bo

    2015-01-01

    We have carried out 200,000 N-body simulations of three identical stellar embryos with masses from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions, while accreting using Bondi-Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. To illustrate the simulations we introduce the 'triple diagnostic diagram', which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations. The separation distribution function is in good correspondence with...

  20. A field guide to the binary stars

    Science.gov (United States)

    Trimble, V.

    1983-05-01

    Details and examples of the six phases of existence for a binary star system are described. The birth and pre-main-sequence contraction is generally obscured from observation by the presence of gas and dust clouds; it comprises 1/1000th of a system's lifetime. The main sequence, i.e., hydrogen burning, takes up to 90 pct of a star's lifetime, and has been detected in stars with masses ranging from 0.07-32 solar masses. In binary systems, the main sequence stars may or may not interact, or one companion may burn out before the other leaves the main sequence. The primary in a binary system expands to fill its Roche lobe before mass transfer begins, then continues on a Kelvin-Helmholtz time scale until the primary is smaller than the secondary, when transfer proceeds on a nuclear time scale. The depletion of hydrogen fuel or He ignition stops the mass transfer, leading to formation of a white dwarf, neutron star, or supernova that sends both the neutron star and the OB secondary off at high speeds. Back transfer can be initiated in a fifth phase and can produce black holes or dwarf novae, or supernovae. Finally, the system terminates when both stars are extinguished and fall into one another, which can also yield supernovae or black holes.

  1. On the binary expansions of algebraic numbers

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.; Pomerance, Carl

    2003-07-01

    Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.

  2. Searching for Binary Supermassive Black Holes via Variable Broad Emission Line Shifts: Low Binary Fraction

    CERN Document Server

    Wang, Lile; Ju, Wenhua; Rafikov, Roman R; Ruan, John J; Schneider, Donald P

    2016-01-01

    Supermassive black hole binaries (SMBHs) are expected to result from galaxy mergers, and thus are natural byproducts (and probes) of hierarchical structure formation in the Universe. They are also the primary expected source of low-frequency gravitational wave emission. We search for binary BHs using time-variable velocity shifts in broad Mg II emission lines of quasars with multi-epoch observations. First, we inspect velocity shifts of the binary SMBH candidates identified in Ju et al. (2013), using SDSS spectra with an additional epoch of data that lengthens the typical baseline to ~10 yr. We find variations in the line-of-sight velocity shifts over 10 years that are comparable to the shifts observed over 1-2 years, ruling out the binary model for the bulk of our candidates. We then analyze 1438 objects with 8 yr median time baselines, from which we would expect to see velocity shifts >1000 km/s from sub-pc binaries. We find only one object with an outlying velocity of 448 km/s, indicating, based on our mod...

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

    CERN Document Server

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

    2015-01-01

    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. Merging binary black holes formed through chemically homogeneous evolution in short-period stellar binaries

    CERN Document Server

    Mandel, Ilya

    2016-01-01

    We explore a newly proposed channel to create binary black holes of stellar origin. This scenario applies to massive, tight binaries where mixing induced by rotation and tides transports the products of hydrogen burning throughout the stellar envelopes. This slowly enriches the entire star with helium, preventing the build-up of an internal chemical gradient. The stars remain compact as they evolve nearly chemically homogeneously, eventually forming two black holes, which, we estimate, typically merge 4 to 11 Gyr after formation. Like other proposed channels, this evolutionary pathway suffers from significant theoretical uncertainties, but could be constrained in the near future by data from advanced ground-based gravitational-wave detectors. We perform Monte Carlo simulations of the expected merger rate over cosmic time to explore the implications and uncertainties. Our default model for this channel yields a local binary black hole merger rate of about $10$ Gpc$^{-3}$ yr$^{-1}$ at redshift $z=0$, peaking at...

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2013-10-01

    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—cool, evolved stars of ∼5 M {sub ☉}—are 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 η 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.

  6. A precontact binary and a shallow contact binary are in the same field

    Science.gov (United States)

    Liu, Liang; Qian, Shengbang; He, Jiajia; Liao, Wenping; Liu, Nianping

    2016-06-01

    The period changes of two close binaries, V1107 Cas and AX Cas, which are in the same field, were investigated. Their periods both show a long-term decrease. After further analysis, we found that the periods have their respective cyclic oscillations (T3 = 6.74 ± 0.24 yr for V1107 Cas and T3 = 13.8 ± 0.3 yr for AX Cas), which are possibly caused by a third body due to the light-time effect. We also obtained the complete VRcIc light curves for V1107 Cas and analyzed them with the 2010 version of the Wilson-Devinney code. The photometric results reveal that V1107 Cas is a W-type shallow contact (15.2%±1.8%) binary, with a mass-ratio of 1.797 ± 0.006. The period variation and photometric solution suggest that V1107 Cas is a newly formed contact binary system. Moreover, we estimated the fundamental parameters for V1107 Cas. They are: M1 = 0.39 ± 0.01 M⊙, M2 = 0.70 ± 0.03 M⊙, R1 = 0.52 ± 0.10 R⊙, R2 = 0.68 ± 0.12 R⊙, L1 = 0.178 ± 0.108 L⊙, and L2 = 0.196 ± 0.116 L⊙. Then, based on the coplane assumption, we deduced the masses of possible third bodies to be M3 = 0.091 ± 0.019 M⊙ for V1107 Cas and M3 = 0.325 ± 0.029 M⊙ for AX Cas. Finally, we inferred the evolutional stage of AX Cas, and believe that it is a precontact binary. Thus, the precontact binary AX Cas and the shallow contact binary V1107 Cas have adjoining evolutional stages.

  7. Binary pairs of supermassive black holes - Formation in merging galaxies

    International Nuclear Information System (INIS)

    A process in which supermassive binary blackholes are formed in nuclei of supergiant galaxies due to galaxy mergers is examined. There is growing evidence that mergers of galaxies are common and that supermassive black holes in center of galaxies are also common. Consequently, it is expected that binary black holes should arise in connection with galaxy mergers. The merger process in a galaxy modeled after M87 is considered. The capture probability of a companion is derived as a function of its mass. Assuming a correlation between the galaxy mass and the blackholes mass, the expected mass ratio in binary black holes is calculated. The binary black holes formed in this process are long lived, surviving longer than the Hubble time unless they are perturbed by black holes from successive mergers. The properties of these binaries agree with Gaskell's (1988) observational work on quasars and its interpretation in terms of binary black holes. 39 refs

  8. Microlensing Binaries Discovered through High-magnification Channel

    DEFF Research Database (Denmark)

    Shin, I.-G; Gould, A.; Choi, J.-Y;

    2012-01-01

    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 eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturba......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 eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010...... 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....

  9. Milankovitch Cycles of Terrestrial Planets in Binary Star Systems

    CERN Document Server

    Forgan, Duncan H

    2016-01-01

    The habitability of planets in binary star systems depends not only on the radiation environment created by the two stars, but also on the perturbations to planetary orbits and rotation produced by the gravitational field of the binary and neighbouring planets. Habitable planets in binaries may therefore experience significant perturbations in orbit and spin. The direct effects of orbital resonances and secular evolution on the climate of binary planets remain largely unconsidered. We present latitudinal energy balance modelling of exoplanet climates with direct coupling to an N Body integrator and an obliquity evolution model. This allows us to simultaneously investigate the thermal and dynamical evolution of planets orbiting binary stars, and discover gravito-climatic oscillations on dynamical and secular timescales. We investigate the Kepler-47 and Alpha Centauri systems as archetypes of P and S type binary systems respectively. In the first case, Earthlike planets would experience rapid Milankovitch cycle...

  10. Low Frequency Gravitational Waves from White Dwarf MACHO Binaries

    CERN Document Server

    Hiscock, W A; Routzahn, J R; Kulick, B; Hiscock, William A.; Larson, Shane L.; Routzahn, Joshua R.; Kulick, Ben

    2000-01-01

    The possibility that Galactic halo MACHOs are white dwarfs has recently attracted much attention. Using the known properties of white dwarf binaries in the Galactic disk as a model, we estimate the possible contribution of halo white dwarf binaries to the low-frequency (10^{-5} Hz} < f < 10^{-1}Hz) gravitational wave background. Assuming the fraction of white dwarfs in binaries is the same in the halo as in the disk, we find the confusion background from halo white dwarf binaries could be five times stronger than the expected contribution from Galactic disk binaries, dominating the response of the proposed space based interferometer LISA. Low-frequency gravitational wave observations will be the key to discovering the nature of the dark MACHO binary population.

  11. Distinguishing Between Formation Channels for Binary Black Holes with LISA

    CERN Document Server

    Breivik, Katelyn; Larson, Shane L; Kalogera, Vassiliki; Rasio, Frederic A

    2016-01-01

    The recent detections of GW150914 and GW151226 imply an abundance of stellar-mass binary-black-hole mergers in the local universe. While ground-based gravitational-wave detectors are limited to observing the final moments before a binary merges, space-based detectors, such as the Laser Interferometer Space Antenna (LISA), can observe binaries at lower orbital frequencies where such systems may still encode information about their formation histories. In particular, the orbital eccentricity of binary black holes in the LISA frequency band can be used discriminate between binaries formed in isolation in galactic fields, and those formed in dense stellar environments such as globular clusters. In this letter, we explore the differences in orbital eccentricities of binary black hole populations as they evolve through the LISA frequency band. Overall we find that there are three distinct populations of orbital eccentricities discernible by LISA. We show that, depending on gravitational-wave frequency, anywhere fro...

  12. Evolution Of Binary Supermassive Black Holes In Rotating Nuclei

    CERN Document Server

    Rasskazov, Alexander

    2016-01-01

    Interaction of a binary supermassive black hole with stars in a galactic nucleus can result in changes to all the elements of the binary's orbit, including the angles that define its orientation. If the nucleus is rotating, the orientation changes can be large, causing large changes in the binary's orbital eccentricity as well. We present a general treatment of this problem based on the Fokker-Planck equation for f, defined as the probability distribution for the binary's orbital elements. First- and second-order diffusion coefficients are derived for the orbital elements of the binary using numerical scattering experiments, and analytic approximations are presented for some of these coefficients. Solutions of the Fokker-Planck equation are then derived under various assumptions about the initial rotational state of the nucleus and the binary hardening rate. We find that the evolution of the orbital elements can become qualitatively different when we introduce nuclear rotation: 1) the orientation of the binar...

  13. Nonlinear Dynamics, Lorenz Model and Formation of Binary Stars

    OpenAIRE

    Chang, Yi-Fang

    2008-01-01

    Based on the Lorenz model derived from the equations of hydrodynamics of nebula, we discuss the formation of binary stars by the qualitative analysis theory of nonlinear equation. Here the two wings in the Lorenz model form just the binary stars, whose Roche surface is result of evolution under certain condition. The nonlinear interaction plays a crucial role, and is necessary condition of the formation of binary stars and of multiple stars. While the linear equations form only a single star....

  14. On the formation of Be stars through binary interaction

    OpenAIRE

    Shao, Yong; Li, Xiang-Dong

    2014-01-01

    Be stars are rapidly rotating B type stars. The origin of their rapid rotation is not certain, but binary interaction remains to be a possibility. In this work we investigate the formation of Be stars resulting from mass transfer in binaries in the Galaxy. We calculate the binary evolution with both stars evolving simultaneously and consider different possible mass accretion histories for the accretor. From the calculated results we obtain the critical mass ratios $q_{\\rm cr}$ that determine ...

  15. Magnetic Interaction in Ultra-compact Binary Systems

    CERN Document Server

    Wu, Kinwah

    2009-01-01

    This article reviews the current works on ultra-compact double-degenerate binaries in the presence of magnetic interaction, in particular, unipolar induction. The orbital dynamics and evolution of compact white-dwarf pairs are discussed in detail. Models and predictions of electron cyclotron masers from unipolar-inductor compact binaries and unipolar-inductor white-dwarf planetary systems are presented. Einstein-Laub effects in compact binaries are briefly discussed.

  16. Magnetic interaction in ultra-compact binary systems

    Institute of Scientific and Technical Information of China (English)

    Kinwah WU

    2009-01-01

    This article reviews the current works on ultra-compact double-degenerate binaries in the presence of magnetic interaction, in particular, unipolar induction. The orbital dynamics and evolution of compact white-dwarf pairs are discussed in detail. Models and predictions of electron cyclotron masers from unipolar-inductor compact binaries and unipolar-inductor white-dwarf planetary systems are presented. Einstein-Laub effects in compact binaries are briefly discussed.

  17. How I Learned to Stop Worrying and Love Eclipsing Binaries

    OpenAIRE

    Moe, Maxwell

    2015-01-01

    Relatively massive B-type stars with closely orbiting stellar companions can evolve to produce Type Ia supernovae, X-ray binaries, millisecond pulsars, mergers of neutron stars, gamma ray bursts, and sources of gravitational waves. However, the formation mechanism, intrinsic frequency, and evolutionary processes of B-type binaries are poorly understood. As of 2012, the binary statistics of massive stars had not been measured at low metallicities, extreme mass ratios, or intermediate orbital ...

  18. Segregation phases in a vibrated binary granular layer

    OpenAIRE

    Reis, P. M.; Ehrhardt, G.; Mullin, T.

    2003-01-01

    We present the results of an experimental study of patterned segregation in a horizontally shaken shallow layer of a binary mixture of dry particles. As the compacity, $C$, of the mixture was increased, the evolution of three distinct phases was observed. We classify them as binary gas, segregation liquid and segregation crystal phases using macroscopic and microscopic measures. The binary gas to segregation liquid transition is consistent with a continuous phase transition and includes the c...

  19. Automatic classification of eclipsing binaries light curves using neural networks

    CERN Document Server

    Sarro, L M; Giménez, A

    2005-01-01

    In this work we present a system for the automatic classification of the light curves of eclipsing binaries. This system is based on a classification scheme that aims to separate eclipsing binary sistems according to their geometrical configuration in a modified version of the traditional classification scheme. The classification is performed by a Bayesian ensemble of neural networks trained with {\\em Hipparcos} data of seven different categories including eccentric binary systems and two types of pulsating light curve morphologies.

  20. Information Measures: the Curious Case of the Binary Alphabet

    OpenAIRE

    Jiao, Jiantao; Courtade, Thomas; No, Albert; Venkat, Kartik; Weissman, Tsachy

    2014-01-01

    Four problems related to information divergence measures defined on finite alphabets are considered. In three of the cases we consider, we illustrate a contrast which arises between the binary-alphabet and larger-alphabet settings. This is surprising in some instances, since characterizations for the larger-alphabet settings do not generalize their binary-alphabet counterparts. Specifically, we show that $f$-divergences are not the unique decomposable divergences on binary alphabets that sati...

  1. Status and Future of Deep Searches for Compact Binary Mergers

    Science.gov (United States)

    Nitz, Alexander` Harvey; LIGO Scientific Collaboration

    2016-06-01

    Deep offline searches for gravitational waves from binary black hole, binary neutron star, and neutron star- black hole mergers were conducted during the first Advanced LIGO observing run, and recently Advanced LIGO announced the first detection of gravitational waves from a binary black hole merger. We discuss the recent results, the methodology of the high latency searches, along with improvements for the upcoming observing runs.

  2. Asymptotic bound on binary self-orthogonal codes

    Institute of Scientific and Technical Information of China (English)

    DING Yang

    2009-01-01

    We present two constructions for binary self-orthogonal codes. It turns out that our constructions yield a constructive bound on binary self-orthogonal codes. In particular, when the in-formation rate R = 1/2, by our constructive lower bound, the relative minimum distance δ≈ 0.0595 (for GV bound, δ≈0.110). Moreover, we have proved that the binary self-orthogonal codes asymptotically achieve the Gilbert-Varshamov bound.

  3. Asymptotic bound on binary self-orthogonal codes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    We present two constructions for binary self-orthogonal codes. It turns out that our constructions yield a constructive bound on binary self-orthogonal codes. In particular, when the in-formation rate R = 1/2, by our constructive lower bound, the relative minimum distance δ≈ 0.0595 (for GV bound, δ≈ 0.110). Moreover, we have proved that the binary self-orthogonal codes asymptotically achieve the Gilbert-Varshamov bound.

  4. ANNEXATION OF TWO KINDS OF SOLUTION IN BINARY METALLIC MELTS

    Institute of Scientific and Technical Information of China (English)

    J.Zhang

    2004-01-01

    After investigation on the thervnodynamic properties of a small number of binary metallic melts,the structural units of which cannot be wholly determined by the corresponding phase diagrams,it was found that they can be determined by the principle of annexation of two kinds of solutions in binary metallic melts.According to the principle of annexation,calculating models of mass action concentrations for several binary metallic melts have been formulated.The calculated results agree well with practice,showing that this principle is a reliable basis for determination of the structural units for some binary metallic melts.

  5. Improving geothermal power plants with a binary cycle

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  6. White-Light Flares on Close Binaries Observed with Kepler

    CERN Document Server

    Gao, Qing; Liu, Ji-Feng; Zhang, Xiao-Bin; Gao, Shuang

    2016-01-01

    Based on Kepler data, we present the results of a search for white-light flares on 1049 close binaries. We identify 234 flare binaries, on which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies ("detachedness"). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10-20 percent lower than those in detached and semi-detached systems. We calculate the binary flares activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P_orb) and rotation period (P_rot, calculated for only detached binaries). We find that AL increases with decreasing P_orb or P_rot up to the critical values at P_orb near 3 days or P_rot near 1.5 days, thereafter, the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in 2 eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate ...

  7. Intervals of balanced binary trees in the Tamari lattice

    CERN Document Server

    Giraudo, Samuele

    2011-01-01

    We show that the set of balanced binary trees is closed by interval in the Tamari lattice. We establish that the intervals [T, T'] where T and T' are balanced binary trees are isomorphic as posets to a hypercube. We introduce synchronous grammars that allow to generate tree-like structures and obtain fixed-point functional equations to enumerate these. We also introduce imbalance tree patterns and show that they can be used to describe some sets of balanced binary trees that play a particular role in the Tamari lattice. Finally, we investigate other families of binary trees that are also closed by interval in the Tamari lattice.

  8. Observational signatures of binary supermassive black holes

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, Constanze; Krolik, Julian H. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Miller, M. Coleman [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

    2014-04-20

    Observations indicate that most massive galaxies contain a supermassive black hole, and theoretical studies suggest that when such galaxies have a major merger, the central black holes will form a binary and eventually coalesce. Here we discuss two spectral signatures of such binaries that may help distinguish them from ordinary active galactic nuclei. These signatures are expected when the mass ratio between the holes is not extreme and the system is fed by a circumbinary disk. One such signature is a notch in the thermal continuum that has been predicted by other authors; we point out that it should be accompanied by a spectral revival at shorter wavelengths and also discuss its dependence on binary properties such as mass, mass ratio, and separation. In particular, we note that the wavelength λ {sub n} at which the notch occurs depends on these three parameters in such a way as to make the number of systems displaying these notches ∝λ{sub n}{sup 16/3}; longer wavelength searches are therefore strongly favored. A second signature, first discussed here, is hard X-ray emission with a Wien-like spectrum at a characteristic temperature ∼100 keV produced by Compton cooling of the shock generated when streams from the circumbinary disk hit the accretion disks around the individual black holes. We investigate the observability of both signatures. The hard X-ray signal may be particularly valuable as it can provide an indicator of black hole merger a few decades in advance of the event.

  9. Electronic band structures of binary skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Banaras [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Aliabad, H.A. Rahnamaye [Department of Physics, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Saifullah [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Jalali-Asadabadi, S. [Department of Physics, Faculty of Science, University of Isfahan (UI), 81744 Isfahan (Iran, Islamic Republic of); Khan, Imad [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Ahmad, Iftikhar, E-mail: ahma5532@gmail.com [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan)

    2015-10-25

    The electronic properties of complex binary skutterudites, MX{sub 3} (M = Co, Rh, Ir; X = P, As, Sb) are explored, using various density functional theory (DFT) based theoretical approaches including Green's Function (GW) as well as regular and non-regular Tran Blaha modified Becke Jhonson (TB-mBJ) methods. The wide range of calculated bandgap values for each compound of this skutterudites family confirm that they are theoretically as challenging as their experimental studies. The computationally expensive GW method, which is generally assume to be efficient in the reproduction of the experimental bandgaps, is also not very successful in the calculation of bandgaps. In this article, the issue of the theoretical bandgaps of these compounds is resolved by reproducing the accurate experimental bandgaps, using the recently developed non-regular TB-mBJ approach, based on DFT. The effectiveness of this technique is due to the fact that a large volume of the binary skutterudite crystal is empty and hence quite large proportion of electrons lie outside of the atomic spheres, where unlike LDA and GGA which are poor in the treatment of these electrons, this technique properly treats these electrons and hence reproduces the clear electronic picture of these compounds. - Highlights: • Theoretical and experimental electronic band structures of binary skutterudites are reviewed. • The literature reveals that none of the existing theoretical results are consistent with the experiments. • GW, regular and non-regular TB-mBJ methods are used to reproduce the correct results. • The GW and regular TB-mBJ results are better than the available results in literature. • However, non-regular TB-mBJ reproduces the correct experimental band structures.

  10. Sulfated binary and trinary oxide solid superacids

    Institute of Scientific and Technical Information of China (English)

    缪长喜; 华伟明; 陈建民; 高滋

    1996-01-01

    A series of sulfated binary and trinary oxide solid superacids were prepared, and their catalytic activities for n-butane isomerization at low temperature were measured. The incorporation of different metal oxides into ZrO2 may produce a positive or negative effect on the acid strength and catalytic activity of the solid superacids. Sulfated oxides of Cr-Zr, Fe-Cr-Zr and Fe-V-Zr are 2 - 3 times more active than the reported sulfated Fe-Mn-Zr oxide. The enhancement in the superacidity and catalytic activity of these new solid superacids has been discussed on account of the results of various characteriation techniques.

  11. On Totally Reducible Binary Forms: I

    Indian Academy of Sciences (India)

    C Hooley

    2001-08-01

    Let () be the number of positive numbers up to a large limit that are expressible in essentially more than one way by a binary form that is a product of > 2 distinct linear factors with integral coefficients. We prove that $$(n) = O\\left(n^{2/l-_l+\\epsilon}\\right),$$ where \\begin{equation*}_l=\\begin{cases}1/l^2, \\quad\\text{if}\\quad l=3,\\\\ (l-2)/l^2(l-1), \\quad\\text{if}\\quad l>3,\\end{cases}\\end{equation*} thus demonstrating in particular that it is exceptional for a number represented by to have essentially more than one representation.

  12. Computer Vision Using Local Binary Patterns

    CERN Document Server

    Pietikainen, Matti; Zhao, Guoying; Ahonen, Timo

    2011-01-01

    The recent emergence of Local Binary Patterns (LBP) has led to significant progress in applying texture methods to various computer vision problems and applications. The focus of this research has broadened from 2D textures to 3D textures and spatiotemporal (dynamic) textures. Also, where texture was once utilized for applications such as remote sensing, industrial inspection and biomedical image analysis, the introduction of LBP-based approaches have provided outstanding results in problems relating to face and activity analysis, with future scope for face and facial expression recognition, b

  13. Interatomic Potentials for Some Binary Oxides

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using atomistic computer simulation methods we have derived a new set of interatomic potential parameters for some binary oxides, comprising divalent transition elements (rock-salt structured)and tetrava)ent metals. Computational techniques based on the minimization of the crystal energy with respect to atomic coordinates have been employed. Crystal properties were calculated and compared with the experimental data to check the reliability of our potential models. Intrinsic (Schottky and Frenkel) defect energies were also calculated and compared with previous studies.There is a good agreement between these calculations, which shows that the new potential parameters are reliable and can be used with confidence for future investigations.

  14. Statistical kinetic treatment of relativistic binary collisions.

    Science.gov (United States)

    Peano, F; Marti, M; Silva, L O; Coppa, G

    2009-02-01

    In particle-based algorithms, the effect of binary collisions is commonly described in a statistical way, using Monte Carlo techniques. It is shown that, in the relativistic regime, stringent constraints should be considered on the sampling of particle pairs for collision, which are critical to ensure physically meaningful results, and that nonrelativistic sampling criteria (e.g., uniform random pairing) yield qualitatively wrong results, including equilibrium distributions that differ from the theoretical Jüttner distribution. A general procedure for relativistically consistent algorithms is provided, and verified with three-dimensional Monte Carlo simulations, thus opening the way to the numerical exploration of the statistical properties of collisional relativistic systems. PMID:19391799

  15. Binary Colloidal Alloy Test-5: Phase Separation

    Science.gov (United States)

    Lynch, Matthew; Weitz, David A.; Lu, Peter J.

    2008-01-01

    The Binary Colloidal Alloy Test - 5: Phase Separation (BCAT-5-PhaseSep) experiment will photograph initially randomized colloidal samples onboard the ISS to determine their resulting structure over time. This allows the scientists to capture the kinetics (evolution) of their samples, as well as the final equilibrium state of each sample. BCAT-5-PhaseSep studies collapse (phase separation rates that impact product shelf-life); in microgravity the physics of collapse is not masked by being reduced to a simple top and bottom phase as it is on Earth.

  16. Multiple Human Tracking Using Binary Infrared Sensors

    Directory of Open Access Journals (Sweden)

    Toshiaki Miyazaki

    2015-06-01

    Full Text Available To create a context-aware environment, human locations and movement paths must be considered. In this paper, we propose an algorithm that tracks human movement paths using only binary sensed data obtained by infrared (IR sensors attached to the ceiling of a room. Our algorithm can estimate multiple human movement paths without a priori knowledge of the number of humans in the room. By repeating predictions and estimations of human positions and links from the previous human positions to the estimated ones at each time period, human movement paths can be estimated. Simulation-based evaluation results show that our algorithm can dynamically trace human movement paths.

  17. Iterative Method for Generating Correlated Binary Sequences

    CERN Document Server

    Usatenko, O V; Apostolov, S S; Makarov, N M; Krokhin, A A

    2014-01-01

    We propose a new efficient iterative method for generating random correlated binary sequences with prescribed correlation function. The method is based on consecutive linear modulations of initially uncorrelated sequence into a correlated one. Each step of modulation increases the correlations until the desired level has been reached. Robustness and efficiency for the proposed algorithm are tested by generating sequences with inverse power-law correlations. The substantial increase in the strength of correlation in the iterative method with respect to the single-step filtering generation is shown for all studied correlation functions. Our results can be used for design of disordered superlattices, waveguides, and surfaces with selective transport properties.

  18. 6384 Kervin: A Possible Hungaria Binary Asteroid

    Science.gov (United States)

    Warner, Brian D.; Aznar Macia, Amadeo

    2016-04-01

    Analysis of CCD photometric observations in late 2015 of the Hungaria asteroid 6384 Kervin indicates that it may be a binary asteroid with a primary lightcurve of P1 = 3.6194 ± 0.0001 h, A1 = 0.06 ± 0.01 mag. The secondary lightcurve parameters are P2 = 15.94 ± 0.01 h, A2 = 0.03 ± 0.01 mag. No mutual events (occultations or eclipses) were observed. However, other indicators give an estimated diameter ratio on the order of Ds/Dp ~ 0.3, possibly greater.

  19. Associative memory - An optimum binary neuron representation

    Science.gov (United States)

    Awwal, A. A.; Karim, M. A.; Liu, H. K.

    1989-01-01

    Convergence mechanism of vectors in the Hopfield's neural network is studied in terms of both weights (i.e., inner products) and Hamming distance. It is shown that Hamming distance should not always be used in determining the convergence of vectors. Instead, weights (which in turn depend on the neuron representation) are found to play a more dominant role in the convergence mechanism. Consequently, a new binary neuron representation for associative memory is proposed. With the new neuron representation, the associative memory responds unambiguously to the partial input in retrieving the stored information.

  20. Model for magnetic-nonmagnetic binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Razafimandimby, H. [Departement de Physique, Universite de Toliara, 601 Toliara (Madagascar); Randrianasoloharisoa, D. [LPMR, Universite d' Antananarivo (Madagascar); Rakotomahevitra, A. [Departement des Sciences Exactes, Universite de Mahajanga, BP 155 (Madagascar); Parlebas, J.C. [IPCMS, UMR 7504 CNRS-Universite Louis Pasteur, 23 rue du Loess, BP 43, 67034 Strasbourg (France)

    2007-10-15

    An extension of a mean-field approximation (MFA) developed within standard basis operators (SBO) is used to study magnetism in magnetic-nonmagnetic binary alloys. The Curie temperature is calculated from the free energy within the framework of the present approach. The calculated results are in fair agreement with the theoretical results of other research groups for the same problem but utilizing other methods. Finally, the case of NiPt alloys is briefly examined as an example test for the comparison with experiment. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Is the Coma cluster binary dominated?

    International Nuclear Information System (INIS)

    It is investigated whether the model of an expanding cluster dominated by a massive binary galaxy, first suggested by Valtonen and Byrd (1979), is consistent with optical data on the surface density and velocity dispersion of the Coma cluster. The evolution of this model is simulated for a wide variety of initial conditions. It is found that galaxy counts in the model can be made to agree with observation, but that the observed velocity dispersion profile cannot be reproduced. A number of other arguments suggest that the central galaxies in Coma cannot be as massive as required by the model. This model is not a viable representation of the Coma cluster. 25 refs

  2. The Benchmark Eclipsing Binary V530 Ori

    DEFF Research Database (Denmark)

    Torres, Guillermo; Lacy, Claud H. Sandberg; Pavlovski, Kresimir;

    2015-01-01

    We report accurate measurements of the physical properties (mass, radius, temperature) of components of the G+M eclipsing binary V530 On. The M-type secondary shows a larger radius and a cooler temperature than predicted by standard stellar evolution models, as has been found for many other low-m......-mass stars and ascribed to the effects of magnetic activity and/or spots. We show that models from the Dartmouth series that incorporate magnetic fields are able to match the observations with plausible field strengths of 1-2 kG, consistent with a rough estimate we derive for that star....

  3. UV Emission line shifts of symbiotic binaries

    OpenAIRE

    Friedjung, M.; Mikolajewska, J.; Zajczyk, A.; Eriksson, M.

    2010-01-01

    Relative and absolute emission line shifts have been previously found for symbiotic binaries, but their cause was not clear. This work aims to better understand the emission line shifts. Positions of strong emission lines were measured on archival UV spectra of Z And, AG Dra, RW Hya, SY Mus and AX Per and relative shifts between the lines of different ions compared. Profiles of lines of RW Hya and Z And were also examined. The reality of the relative shift between resonance and intercombinati...

  4. Binary quadratic forms an algorithmic approach

    CERN Document Server

    Buchmann, Johannes

    2007-01-01

    The book deals with algorithmic problems related to binary quadratic forms, such as finding the representations of an integer by a form with integer coefficients, finding the minimum of a form with real coefficients and deciding equivalence of two forms. In order to solve those problems, the book introduces the reader to important areas of number theory such as diophantine equations, reduction theory of quadratic forms, geometry of numbers and algebraic number theory. The book explains applications to cryptography. It requires only basic mathematical knowledge.

  5. Binary Modulation Formats in Optical Access Networks

    Directory of Open Access Journals (Sweden)

    Vladimir Tejkal

    2010-01-01

    Full Text Available In this paper the binary modulation formats and their application in passive optical networks have been discussed. Passive optical networks are characterized by dividing the optical signal between several end users by using passive splitters, which added a significant attenuation to the network. The performance of the selected modulation formats, depending on the transmitter power in order to verify that there is no signal distortion, has been examined in our simulations. A minimal error rate of the system for each modulation format has been also examined. Finding a suitable modulation, which would allow extension of the distance and splitting ration in current passive optical networks, has been the main aim.

  6. Double riches: asteroseismology in eclipsing binaries

    CERN Document Server

    Southworth, John

    2015-01-01

    The study of eclipsing binaries is our primary source of measured properties of normal stars, achieved through analysis of light and radial velocity curves of eclipsing systems. The study of oscillations and pulsations is increasingly vital for determining the properties of single stars, and investigating the physical phenomena active in their interiors. Combining the two methods holds the promise of establishing stringent tests of stellar evolutionary theory, and of calibrating model-dependent asteroseismology with empirically measured stellar properties. I review recent advances and outline future work.

  7. Heats of formation of binary semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V.; Sastry, B.S.R. [Department of Electronics and Instrumentation Indian School of Mines, Dhanbad 826 004 (India)

    2005-03-01

    Heats of formation of tetrahedrally coordinated II-VI and III-V groups of binary semiconductors have been calculated using plasmon energy data. Two simple relations between plasmon energy and heats of formation have been proposed. One is based on spectroscopic model of Phillips and Van Vechten and other is based on the best-fit data of heats of formation. The calculated values of heats of formation from both the equations are compared with the experimental values and the values reported by earlier workers. A fairly good agreement has been obtained between them. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    International Nuclear Information System (INIS)

    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' ∼> 10-100 M⊕ at orbital periods P ≈ 1-10 days. The nearly static 'equilibrium' tidal distortion is, however, stable to parametric resonance except for solar binaries with P ∼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 ≈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 ∼< 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

  9. Nonlinear Tides in Close Binary Systems

    Science.gov (United States)

    Weinberg, Nevin N.; Arras, Phil; Quataert, Eliot; Burkart, Josh

    2012-06-01

    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' >~ 10-100 M ⊕ at orbital periods P ≈ 1-10 days. The nearly static "equilibrium" tidal distortion is, however, stable to parametric resonance except for solar binaries with P 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 ≈ 103[P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of ≈N faster than the standard three

  10. Randomized Binary Consensus with Faulty Agents

    Directory of Open Access Journals (Sweden)

    Alexander Gogolev

    2014-05-01

    Full Text Available This paper investigates self-organizing binary majority consensus disturbed by faulty nodes with random and persistent failure. We study consensus in ordered and random networks with noise, message loss and delays. Using computer simulations, we show that: (1 explicit randomization by noise, message loss and topology can increase robustness towards faulty nodes; (2 commonly-used faulty nodes with random failure inhibit consensus less than faulty nodes with persistent failure; and (3 in some cases, such randomly failing faulty nodes can even promote agreement.

  11. Formation of Nanoparticles in binary polymer mixtures

    Science.gov (United States)

    Cai, Tong; Lu, Xihua; Hu, Zhibin

    2000-10-01

    Formation of Nanoparticles in binary polymer mixtures Tong CAI, Xihua LU, and Zhibin HU Department of Physics, Denton, TX76203 The nanoparticles of hydrorypropyl cellulose (HPC)-polyacrylic acid (PAA) complex have been studied using light scattering method. The formation of the nanoparticles results from the hydrogen-bonding interaction between HPC and PAA. The particle size and size distribution, characterized by dynamic light scattering, depend on the HPC concentration, PAA concentration and reactive temperature. Because HPC and PAA have been approved for use inside human body by FDA, the nanoparticle obtained in this study could be used as drug carriers for controlled release.

  12. The orbital evolution of binary galaxies

    Science.gov (United States)

    Chan, R.; Junqueira, S.

    2001-02-01

    We present the results of self-consistent numerical simulations performed to study the orbital circularization of binary galaxies. We have generalized a previous model (Junqueira & de Freitas Pacheco 1994) and confirmed partially their results. The orbital evolution of pairs of galaxies is faster when we consider interacting pairs with contacting ``live'' galaxy halos but the circularization time remains larger than the Hubble time. Besides, the time behavior of the orbits has changed in comparison with previous work because of tidal forces and dynamical friction acting on the halos.

  13. Anonymizing Binary Tables is APX-hard

    CERN Document Server

    Bonizzoni, Paola; Dondi, Riccardo

    2007-01-01

    The problem of publishing personal data without giving up privacy is increasingly important. An interesting formalization is the $k$-anonymization, where all rows in a table are clustered in sets of at least $k$ records, and all the entries for which records in the same cluster have different values are suppressed. The problem has been shown to be NP-hard when the records values are over a ternary alphabet and $k=3$. In this paper we show that the problem is not only NP-hard, but also APX-hard, when the records values are over a binary alphabet and $k=3$.

  14. Binary Nucleation of Water and Sodium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Thomas [Institute of Thermomechanics ASCR, Prague, Czech Republic; Marsik, Frantisek [Institute of Thermomechanics ASCR, Prague, Czech Republic; Palmer, Donald [ORNL

    2005-01-01

    Nucleation processes in the binary water-sodium chloride system are investigated in the sense of the classical nucleation theory (CNT). The CNT is modified to be able to handle the electrolytic nature of the system and is employed to investigate the acceleration of the nucleation process due to the presence of sodium chloride in the steam. This phenomenon, frequently observed in the Wilson zone of steam turbines, is called early condensation. Therefore, the nucleation rates of the water-sodium chloride mixture are of key importance in the power cycle industry.

  15. The Gaia Mission, Binary Stars and Exoplanets

    CERN Document Server

    Eyer, Laurent; Holl, Berry; North, Pierre; Zucker, Shay; Evans, Dafydd W; Pourbaix, Dimitri; Hodgkin, Simon T; Thuillot, William; Mowlavi, Nami; Carry, Benoit

    2015-01-01

    On the 19th of December 2013, the Gaia spacecraft was successfully launched by a Soyuz rocket from French Guiana and started its amazing journey to map and characterise one billion celestial objects with its one billion pixel camera. In this presentation, we briefly review the general aims of the mission and describe what has happened since launch, including the Ecliptic Pole scanning mode. We also focus especially on binary stars, starting with some basic observational aspects, and then turning to the remarkable harvest that Gaia is expected to yield for these objects.

  16. Dynamic Binary Modification Tools, Techniques and Applications

    CERN Document Server

    Hazelwood, Kim

    2011-01-01

    Dynamic binary modification tools form a software layer between a running application and the underlying operating system, providing the powerful opportunity to inspect and potentially modify every user-level guest application instruction that executes. Toolkits built upon this technology have enabled computer architects to build powerful simulators and emulators for design-space exploration, compiler writers to analyze and debug the code generated by their compilers, software developers to fully explore the features, bottlenecks, and performance of their software, and even end-users to extend

  17. Binary magnetic structures in HoEr

    DEFF Research Database (Denmark)

    Howard, B.K.; Bohr, J.

    1991-01-01

    The magnetic structure of a single crystal of the rare earth random alloy Ho50% Er50% has been investigated by elastic neutron diffraction measurements in the temperature range 120-10 K. Three distinct magnetic phases are identified below the Neel temperature of 104 K. The high-temperature phase...... observed between 104 K and 47.5 K is a binary magnetic structure where the holmium and erbium moments belong to different modulated c-axis spirals. The intermediate-temperature phase between 47.5 K and 35 K is a simple basal plane spiral. Below 35 K, the measurements suggest a ferrimagnetic structure in...

  18. Retrograde binaries of massive black holes in circum-binary accretion discs

    CERN Document Server

    Amaro-Seoane, Pau; Dotti, Massimo; Colpi, Monica

    2016-01-01

    We explore the hardening of a massive black hole binary embedded in a circum-binary gas disc when the binary and the gas are coplanar and the gas is counter-rotating. The secondary black hole, revolving in the direction opposite to the gas, experiences a drag from gas-dynamical friction and from direct accretion of part of it. Using two-dimensional (2D) hydrodynamical grid simulations we investigate the effect of changing the accretion prescriptions on the dynamics of the secondary black hole which in turn affect the binary hardening and eccentricity evolution. We find that realistic accretion prescriptions lead to results that differ from those inferred assuming accretion of all the gas within the Roche Lobe of the secondary black hole. Different accretion prescriptions result in different disc's surface densities which alter the black hole's dynamics back. Full 3D SPH realizations of a number of representative cases, run over a shorter interval of time, validate the general trends observed in the less compu...

  19. Merging binary black holes formed through chemically homogeneous evolution in short-period stellar binaries

    Science.gov (United States)

    Mandel, Ilya; de Mink, Selma E.

    2016-05-01

    We explore a newly proposed channel to create binary black holes of stellar origin. This scenario applies to massive, tight binaries where mixing induced by rotation and tides transports the products of hydrogen burning throughout the stellar envelopes. This slowly enriches the entire star with helium, preventing the build-up of an internal chemical gradient. The stars remain compact as they evolve nearly chemically homogeneously, eventually forming two black holes, which we estimate typically merge 4-11 Gyr after formation. Like other proposed channels, this evolutionary pathway suffers from significant theoretical uncertainties, but could be constrained in the near future by data from advanced ground-based gravitational-wave detectors. We perform Monte Carlo simulations of the expected merger rate over cosmic time to explore the implications and uncertainties. Our default model for this channel yields a local binary black hole merger rate of about 10 Gpc-3 yr-1 at redshift z = 0, peaking at twice this rate at z = 0.5. This means that this channel is competitive, in terms of expected rates, with the conventional formation scenarios that involve a common-envelope phase during isolated binary evolution or dynamical interaction in a dense cluster. The events from this channel may be distinguished by the preference for nearly equal-mass components and high masses, with typical total masses between 50 and 110 M⊙. Unlike the conventional isolated binary evolution scenario that involves shrinkage of the orbit during a common-envelope phase, short time delays are unlikely for this channel, implying that we do not expect mergers at high redshift.

  20. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta

    2013-10-16

    We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this article are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements.

  1. Can low metallicity binaries avoid merging?

    CERN Document Server

    de Mink, S E; Pols, O R

    2007-01-01

    Rapid mass transfer in a binary system can drive the accreting star out of thermal equilibrium, causing it to expand. This can lead to a contact system, strong mass loss from the system and possibly merging of the two stars. In low metallicity stars the timescale for heat transport is shorter due to the lower opacity. The accreting star can therefore restore thermal equilibrium more quickly and possibly avoid contact. We investigate the effect of accretion onto main sequence stars with radiative envelopes with different metallicities. We find that a low metallicity (Z<0.001), 4 solar mass star can endure a 10 to 30 times higher accretion rate before it reaches a certain radius than a star at solar metallicity. This could imply that up to two times fewer systems come into contact during rapid mass transfer when we compare low metallicity. This factor is uncertain due to the unknown distribution of binary parameters and the dependence of the mass transfer timescale on metallicity. In a forthcoming paper we w...

  2. A Compact Supermassive Binary Black Hole System

    CERN Document Server

    Rodríguez, C; Zavala, R T; Peck, A B; Pollack, L K; Romani, R W

    2006-01-01

    We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black hole pair yet found by more than two orders of magnitude. These results are based upon recent multi-frequency observations using the Very Long Baseline Array (VLBA) which reveal two compact, variable, flat-spectrum, active nuclei within the elliptical host galaxy of 0402+379. Multi-epoch observations from the VLBA also provide constraints on the total mass and dynamics of the system. Low spectral resolution spectroscopy using the Hobby-Eberly Telescope indicates two velocity systems with a combined mass of the two black holes of ~1.5 x 10^8 solar masses. The two nuclei appear stationary while the jets emanating from the weaker of the two nuclei appear to move out and terminate in bright hot spots. The discovery of this system has implications for the number of close binary black holes that might be sources of gravi...

  3. Binary rf pulse compression experiment at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Lavine, T.L.; Spalek, G.; Farkas, Z.D.; Menegat, A.; Miller, R.H.; Nantista, C.; Wilson, P.B.

    1990-06-01

    Using rf pulse compression it will be possible to boost the 50- to 100-MW output expected from high-power microwave tubes operating in the 10- to 20-GHz frequency range, to the 300- to 1000-MW level required by the next generation of high-gradient linacs for linear for linear colliders. A high-power X-band three-stage binary rf pulse compressor has been implemented and operated at the Stanford Linear Accelerator Center (SLAC). In each of three successive stages, the rf pulse-length is compressed by half, and the peak power is approximately doubled. The experimental results presented here have been obtained at low-power (1-kW) and high-power (15-MW) input levels in initial testing with a TWT and a klystron. Rf pulses initially 770 nsec long have been compressed to 60 nsec. Peak power gains of 1.8 per stage, and 5.5 for three stages, have been measured. This corresponds to a peak power compression efficiency of about 90% per stage, or about 70% for three stages, consistent with the individual component losses. The principle of operation of a binary pulse compressor (BPC) is described in detail elsewhere. We recently have implemented and operated at SLAC a high-power (high-vacuum) three-stage X-band BPC. First results from the high-power three-stage BPC experiment are reported here.

  4. The binary-rich cluster Abell 2244

    International Nuclear Information System (INIS)

    A structural, luminosity, and velocity study of the cluster Abell 2244 is presented. A2244 was selected for study from the list of Struble and Rood because of its unusually binary-rich population in an evolved cD-type cluster environment, a contradiction in terms of cluster collapse scenarios versus the formation and survival of bound pairs. In comparison with the Coma cluster, A2244 is a slightly poorer version with a suspected deficiency in the number of cluster members in the core. This evidence, combined with the high-velocity dispersion of the cluster, suggests that a low-velocity population of galaxies has been consumed by the central cD galaxy. The central cD galaxy has a single low-velocity companion deep in its envelope and cross sections of its surface-brightness profile suggest that it is in transition from a depressed central surface-brightness object to a high central concentration system, a point of contention in merger models. All but two of the binary galaxies were found to be projections with other cluster members or stars and, thus, are not in conflict with the advanced dynamical age of the cluster. 35 refs

  5. The Electromagnetic Signals of Compact Binary Mergers

    CERN Document Server

    Piran, T; Rosswog, S

    2012-01-01

    Compact binary mergers are prime sources of gravitational waves (GWs), targeted by current and next generation detectors. The question "what is the observable electromagnetic (EM) signature of a compact binary merger?" is an intriguing one with crucial consequences to the quest for gravitational waves. We present a large set of numerical simulations that focus on the electromagnetic signals that emerge from the dynamically ejected sub-relativistic material. These outflows produce on a time scale of a day macronovae - short-lived optical/UV signals powered by radioactive decay. In addition, the outflow interaction with the surrounding matter inevitably leads to a long-lasting radio emission. We calculate the expected radio signals from these outflows on time scales longer than a year, when the sub-relativistic ejecta dominate the emission. We discuss their detectability in 1.4 GHz and 150 MHz and compare it with an updated estimate of the detectability of short GRBs' orphan afterglows. We find that mergers wit...

  6. Tertiary companions to close spectroscopic binaries

    CERN Document Server

    Tokovinin, A; Thomas, S; Udry, S

    2006-01-01

    We have surveyed a sample of 165 solar-type spectroscopic binaries (SB) with periods from 1 to 30 days for higher-order multiplicity. 62 targets have been observed with the NACO adaptive optics system and 13 new physical tertiary companions were detected. Another 12 new wide companions (5 still tentative) were retrieved from the 2MASS sky survey. Our binaries belong to 161 stellar systems; of these 64 are triple, 11 quadruple and 7 quintuple. After correction for incomplete detection, the fraction of SBs with additional companions is 63% +- 5%. We find that this fraction is a strong function of the SB period P, reaching 96% for P12d. Period distributions of SBs with and without tertiaries are significantly different, but their mass ratio distributions are identical. New statistical data on the multiplicity of close SBs indicate that their periods and mass ratios were established very early, but periods of SBs within triples were further shortened by angular momentum exchange with companions.

  7. ACOUSTIC EFFECTS ON BINARY AEROELASTICITY MODEL

    Directory of Open Access Journals (Sweden)

    Kok Hwa Yu

    2011-10-01

    Full Text Available Acoustics is the science concerned with the study of sound. The effects of sound on structures attract overwhelm interests and numerous studies were carried out in this particular area. Many of the preliminary investigations show that acoustic pressure produces significant influences on structures such as thin plate, membrane and also high-impedance medium like water (and other similar fluids. Thus, it is useful to investigate the structure response with the presence of acoustics on aircraft, especially on aircraft wings, tails and control surfaces which are vulnerable to flutter phenomena. The present paper describes the modeling of structural-acoustic interactions to simulate the external acoustic effect on binary flutter model. Here, the binary flutter model which illustrated as a rectangular wing is constructed using strip theory with simplified unsteady aerodynamics involving flap and pitch degree of freedom terms. The external acoustic excitation, on the other hand, is modeled using four-node quadrilateral isoparametric element via finite element approach. Both equations then carefully coupled and solved using eigenvalue solution. The mentioned approach is implemented in MATLAB and the outcome of the simulated result are later described, analyzed and illustrated in this paper.

  8. OJ 287 binary black hole system

    CERN Document Server

    Valtonen, Mauri

    2011-01-01

    The light curve of the quasar OJ 287 extends from 1891 up today without major gaps. Here we summarize the results of the 2005 - 2010 observing campaign. The main results are the following: (1) The 2005 October optical outburst came at the expected time, thus confirming the general relativistic precession in the binary black hole system. This result disproved the model of a single black hole system with accretion disk oscillations, as well as several toy models of binaries without relativistic precession. In the latter models the main outburst would have been a year later. (2) The nature of the radiation of the 2005 October outburst was expected to be bremsstrahlung from hot gas at the temperature of $3\\times 10^{5}$ $^{\\circ}$K. This was confirmed by combined ground based and ultraviolet observations using the XMM-Newton X-ray telescope. (3) A secondary outburst of the same nature was expected at 2007 September 13. Within the accuracy of observations (about 6 hours), it started at the correct time. Thus the p...

  9. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.;

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing......-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured...... masses of the brown dwarf companions are 0.02 ± 0.01 M⊙ and 0.019 ± 0.002 M⊙ for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low-mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events...

  10. Spectroscopic binaries with components of similar mass

    CERN Document Server

    Lucy, L B

    2006-01-01

    The assertion that there is an intrinsic excess of binaries with mass ratios q \\simeq 1 - the twin hypothesis - is investigated. A strong version of this hypothesis (H_s), due to Lucy & Ricco (1979) and Tokovinin (2000), refers to a narrow peak in the distribution function psi(q) for q \\ga 0.95. A weak version (H_w), due to Halbwachs et al. (2003), refers to a broad peak for q \\ga 0.8. Current data on SB2's is analysed and H_s is found to be statistically significant for a sample restricted to orbits of high precision. But claims that H_s is significant for binaries with special characteristics are not confirmed since the sample sizes are well below the minimum required for a reliable test. With regard to H_w, additional observational evidence is not presented, but evidence to the contrary in the form of Hogeveen's (1992b) model of biased sampling with psi \\propto q^{-2} is criticized. Specifically, his success in thus fitting catalogued data depends on implausible assumptions about the research methodolo...

  11. Thirty New Low-Mass Spectroscopic Binaries

    CERN Document Server

    Shkolnik, Evgenya L; Liu, Michael C; Reid, I Neill; Cameron, Andrew C

    2010-01-01

    As part of our search for young M dwarfs within 25 pc, we acquired high-resolution spectra of 185 low-mass stars compiled by the NStars project that have strong X-ray emission. By cross-correlating these spectra with radial velocity standard stars, we are sensitive to finding multi-lined spectroscopic binaries. We find a low-mass spectroscopic binary fraction of 16% consisting of 27 SB2s, 2 SB3s and 1 SB4, increasing the number of known low-mass SBs by 50% and proving that strong X-ray emission is an extremely efficient way to find M-dwarf SBs. WASP photometry of 23 of these systems revealed two low-mass EBs, bringing the count of known M dwarf EBs to 15. BD -22 5866, the SB4, is fully described in Shkolnik et al. 2008 and CCDM J04404+3127 B consists of a two mid-M stars orbiting each other every 2.048 days. WASP also provided rotation periods for 12 systems, and in the cases where the synchronization time scales are short, we used P_rot to determine the true orbital parameters. For those with no P_rot, we us...

  12. Speakers' choice of frame in binary choice

    Directory of Open Access Journals (Sweden)

    Marc van Buiten

    2009-02-01

    Full Text Available A distinction is proposed between extit{recommending for} preferred choice options and extit{recommending against} non-preferred choice options. In binary choice, both recommendation modes are logically, though not psychologically, equivalent. We report empirical evidence showing that speakers recommending for preferred options predominantly select positive frames, which are less common when speakers recommend against non-preferred options. In addition, option attractiveness is shown to affect speakers' choice of frame, and adoption of recommendation mode. The results are interpreted in terms of three compatibility effects, (i extit{recommendation mode---valence framing compatibility}: speakers' preference for positive framing is enhanced under extit{recommending for} and diminished under extit{recommending against} instructions, (ii extit{option attractiveness---valence framing compatibility}: speakers' preference for positive framing is more pronounced for attractive than for unattractive options, and (iii extit{recommendation mode---option attractiveness compatibility}: speakers are more likely to adopt a extit{recommending for} approach for attractive than for unattractive binary choice pairs.

  13. Modeling and analysis of advanced binary cycles

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, K.

    1997-12-31

    A computer model (Cycle Analysis Simulation Tool, CAST) and a methodology have been developed to perform value analysis for small, low- to moderate-temperature binary geothermal power plants. The value analysis method allows for incremental changes in the levelized electricity cost (LEC) to be determined between a baseline plant and a modified plant. Thermodynamic cycle analyses and component sizing are carried out in the model followed by economic analysis which provides LEC results. The emphasis of the present work is on evaluating the effect of mixed working fluids instead of pure fluids on the LEC of a geothermal binary plant that uses a simple Organic Rankine Cycle. Four resources were studied spanning the range of 265{degrees}F to 375{degrees}F. A variety of isobutane and propane based mixtures, in addition to pure fluids, were used as working fluids. This study shows that the use of propane mixtures at a 265{degrees}F resource can reduce the LEC by 24% when compared to a base case value that utilizes commercial isobutane as its working fluid. The cost savings drop to 6% for a 375{degrees}F resource, where an isobutane mixture is favored. Supercritical cycles were found to have the lowest cost at all resources.

  14. Ordering in binary transition metal alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rusakov, G. [Institute for Metal Physics UB RAS, 18 Kovalevskoj St., 620990 Ekaterinburg (Russian Federation); Ural State Technical University - UPI, 19 Mira St., 620002 Ekaterinburg (Russian Federation); Son, L., E-mail: ldson@yandex.ru [Ural State Pedagogical University, 26 Cosmonavtov Ave, 620017 Ekaterinburg (Russian Federation); Efimova, E. [Institute for Metal Physics UB RAS, 18 Kovalevskoj St., 620990 Ekaterinburg (Russian Federation); Ural State Technical University - UPI, 19 Mira St., 620002 Ekaterinburg (Russian Federation); Dubinin, N. [Institute for Metallurgy UB RAS, 101 Amundsen St., 620016 Ekaterinburg (Russian Federation); Ural State Technical University - UPI, 19 Mira St., 620002 Ekaterinburg (Russian Federation)

    2012-03-20

    We present the phenomenological thermodynamic modeling of binary alloys which demonstrate solubility of the components at high temperatures, and form intermediate phase near equiatomic composition at lower ones (the so-called sigma-phase). Besides, the regular solution miscibility gap takes place also. The nonequilibrium thermodynamic potential is written out as a sum of the free energy of regular solution and polynomial term of scalar order parameter {phi}, which describes the {sigma}-phase ordering. There are four parameters in the model: the energy of regular solution mixing, the energy of {sigma}-phase formation at zero temperature, and the widths of temperature and concentration intervals of {sigma}-phase existence in the alloy with frozen-in random distribution of components. Up to now, both phase transitions which take place in a number of transition metals binary alloys (the {sigma}-phase formation and miscibility in the regular solution) have been treated separately. In present work, the standard technique of phase diagram calculation allows us to analyze all possible phase diagrams which may arise in the alloy.

  15. Binary droplet collision at high Weber number

    Science.gov (United States)

    Pan, Kuo-Long; Chou, Ping-Chung; Tseng, Yu-Jen

    2009-09-01

    By using the techniques developed for generating high-speed droplets, we have systematically investigated binary droplet collision when the Weber number (We) was increased from the range usually tested in previous studies on the order of 10 to a much larger value of about 5100 for water (a droplet at 23 m/s with a diameter of 0.7 mm). Various liquids were also used to explore the effects of viscosity and surface tension. Specifically, beyond the well-known regimes at moderate We’s, which exhibited coalescence, separation, and separation followed by satellite droplets, we found different behaviors showing a fingering lamella, separation after fingering, breakup of outer fingers, and prompt splattering into multiple secondary droplets as We was increased. The critical Weber numbers that mark the boundaries between these impact regimes are identified. The specific impact behaviors, such as fingering and prompt splattering or splashing, share essential similarity with those also observed in droplet-surface impacts, whereas substantial variations in the transition boundaries may result from the disparity of the boundary conditions at impacts. To compare the outcomes of both types of collisions, a simple model based on energy conservation was carried out to predict the maximum diameter of an expanding liquid disk for a binary droplet collision. The results oppose the dominance of viscous drag, as proposed by previous studies, as the main deceleration force to effect a Rayleigh-Taylor instability and ensuing periphery fingers, which may further lead to the formations of satellite droplets.

  16. Convergence Speed of Binary Interval Consensus

    CERN Document Server

    Draief, Moez

    2012-01-01

    We consider the convergence time for solving the binary consensus problem using the interval consensus algorithm proposed by B\\' en\\' ezit, Thiran and Vetterli (2009). In the binary consensus problem, each node initially holds one of two states and the goal for each node is to correctly decide which one of these two states was initially held by a majority of nodes. We derive an upper bound on the expected convergence time that holds for arbitrary connected graphs, which is based on the location of eigenvalues of some contact rate matrices. We instantiate our bound for particular networks of interest, including complete graphs, paths, cycles, star-shaped networks, and Erd\\" os-R\\' enyi random graphs; for these graphs, we compare our bound with alternative computations. We find that for all these examples our bound is tight, yielding the exact order with respect to the number of nodes. We pinpoint the fact that the expected convergence time critically depends on the voting margin defined as the difference betwe...

  17. A Speeding Binary in the Galactic Halo

    Science.gov (United States)

    Kohler, Susanna

    2016-04-01

    The recent discovery of a hyper-velocity binary star system in the halo of the Milky Way poses a mystery: how was this system accelerated to its high speed?Accelerating StarsUnlike the uniform motion in the Galactic disk, stars in the Milky Ways halo exhibit a huge diversity of orbits that are usually tilted relative to the disk and have a variety of speeds. One type of halo star, so-called hyper-velocity stars, travel with speeds that can approach the escape velocity of the Galaxy.How do these hyper-velocity stars come about? Assuming they form in the Galactic disk, there are multiple proposed scenarios through which they could be accelerated and injected into the halo, such as:Ejection after a close encounter with the supermassive black hole at the Galactic centerEjection due to a nearby supernova explosionEjection as the result of a dynamical interaction in a dense stellar population.Further observations of hyper-velocity stars are necessary to identify the mechanism responsible for their acceleration.J1211s SurpriseModels of J1211s orbit show it did not originate from the Galactic center (black dot). The solar symbol shows the position of the Sun and the star shows the current position of J1211. The bottom two panels show two depictions(x-y plane and r-z plane) of estimated orbits of J1211 over the past 10 Gyr. [Nmeth et al. 2016]To this end, a team of scientists led by Pter Nmeth (Friedrich Alexander University, Erlangen-Nrnberg) recently studied the candidate halo hyper-velocity star SDSS J121150.27+143716.2. The scientists obtained spectroscopy of J1211 using spectrographs at the Keck Telescope in Hawaii and ESOs Very Large Telescope in Chile. To their surprise, they discovered the signature of a companion in the spectra: J1211 is actually a binary!Nmeth and collaborators found that J1211, located roughly 18,000 light-years away, is moving at a rapid ~570 km/s relative to the galactic rest frame. The binary system consists of a hot (30,600 K) subdwarf and a

  18. 含B量对激光熔覆FeCoCrNiBx(x=0.5,0.75,1.0,1.25)高熵合金涂层组织结构与耐磨性的影响%Effect of Boron Addition on the Microstructure and Wear Resistance of FeCoCrNiBx (x=0.5, 0.75, 1.0, 1.25) High-Entropy alloy Coating Prepared by Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    陈国进; 张冲; 唐群华; 戴品强

    2015-01-01

    采用激光熔覆技术制备FeCoCrNiBx高熵合金涂层,用X射线衍射(XRD)、扫描电镜(SEM)、硬度和耐磨测试等方法,研究了B含量对激光熔覆FeCoCrNiBx高熵合金涂层的组织结构、硬度和耐磨性能的影响.结果表明,随B含量的增加,合金相结构逐渐由fcc固溶体结构转变为fcc固溶体和M3B相共存,M3B相主要为Cr、Fe硼化物.随B含量的增加,枝晶组织中析出颗粒状和短棒状的M3B相,且M3B相逐渐长大成长条状.B的增加显著提高合金涂层的硬度,由4470 MPa增加到8480 MPa,且磨损量随着B的增加而减少.%The FeCoCrNiBx high-entropy alloy coatings were prepared by laser cladding.The effect of boron addition on microstructure,hardness and wear resistance of FeCoCrNiBx high-entropy alloy coating were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),hardness and wear testers.The results show that with the boron addition increasing,the structure of alloys change from fcc structure to fcc structure with M3B phase precipitation,and M3B phase are mainly borides of Cr and Fe.Meanwhile,the granular and short rod-like M3B phase is precipitated in the coatings.And a blocky M3B phase forms with boron addition.Microhardness and wear resistance are significantly enhanced by the formation M3B phase.The microhardness increases from 4470 to 8480 MPa,and the wear-loss of FeCoCrNiBx high-entropy alloy coating decrease with boron addition.

  19. Convergence of the solutions for the equation x(iv+ax ⃛+bx¨+g(x˙+h(x=p(t,x,x˙,x¨,x ⃛

    Directory of Open Access Journals (Sweden)

    Anthony Uyi Afuwape

    1988-01-01

    Full Text Available This paper is concerned with differential equations of the formx(iv+ax ⃛+bx¨+g(x˙+h(x=p(t,x,x˙,x¨,x ⃛where a, b are positive constants and the functions g, h and p are continuous in their respective arguments, with the function h not necessarily differentiable. By introducing a Lyapunov function, as well as restricting the incrementary ratio η−1{h(ζ+η−h(ζ}, (η≠0, of h to a closed sub-interval of the Routh-Hurwitz interval, we prove the convergence of solutions for this equation. This generalizes earlier results.

  20. ALIGNMENT OF SUPERMASSIVE BLACK HOLE BINARY ORBITS AND SPINS

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M. Coleman [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States); Krolik, Julian H., E-mail: miller@astro.umd.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2013-09-01

    Recent studies of accretion onto supermassive black hole binaries suggest that much, perhaps most, of the matter eventually accretes onto one hole or the other. If so, then for binaries whose inspiral from {approx}1 pc to {approx}10{sup -3}-10{sup -2} pc is driven by interaction with external gas, both the binary orbital axis and the individual black hole spins can be reoriented by angular momentum exchange with this gas. Here we show that, unless the binary mass ratio is far from unity, the spins of the individual holes align with the binary orbital axis in a time {approx}few-100 times shorter than the binary orbital axis aligns with the angular momentum direction of the incoming circumbinary gas; the spin of the secondary aligns more rapidly than that of the primary by a factor {approx}(m{sub 1}/m{sub 2}){sup 1/2} > 1. Thus the binary acts as a stabilizing agent, so that for gas-driven systems, the black hole spins are highly likely to be aligned (or counteraligned if retrograde accretion is common) with each other and with the binary orbital axis. This alignment can significantly reduce the recoil speed resulting from subsequent black hole merger.