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Sample records for post double common-envelope

  1. Testing Common Envelopes on Double White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Nandez, Jose L. A.; Ivanova, Natalia; Lombardi, James C., Jr.

    2015-06-01

    The formation of a double white dwarf binary likely involves a common envelope (CE) event between a red giant and a white dwarf (WD) during the most recent episode of Roche lobe overflow mass transfer. We study the role of recombination energy with hydrodynamic simulations of such stellar interactions. We find that the recombination energy helps to expel the common envelope entirely, while if recombination energy is not taken into account, a significant fraction of the common envelope remains bound. We apply our numerical methods to constrain the progenitor system for WD 1101+364 - a double WD binary that has well-measured mass ratio of q=0.87±0.03 and an orbital period of 0.145 days. Our best-fit progenitor for the pre-common envelope donor is a 1.5 ⊙ red giant.

  2. Orbital period variations in eclipsing post-common-envelope binaries

    NASA Astrophysics Data System (ADS)

    Parsons, S. G.; Marsh, T. R.; Copperwheat, C. M.; Dhillon, V. S.; Littlefair, S. P.; Hickman, R. D. G.; Maxted, P. F. L.; Gänsicke, B. T.; Unda-Sanzana, E.; Colque, J. P.; Barraza, N.; Sánchez, N.; Monard, L. A. G.

    2010-10-01

    We present high-speed ULTRACAM photometry of the eclipsing post-common-envelope binaries DE CVn, GK Vir, NN Ser, QS Vir, RR Cae, RX J2130.6+4710, SDSS 0110+1326 and SDSS 0303+0054 and use these data to measure precise mid-eclipse times in order to detect any period variations. We detect a large (~250 s) departure from linearity in the eclipse times of QS Vir which Applegate's mechanism fails to reproduce by an order of magnitude. The only mechanism able to drive this period change is a third body in a highly elliptical orbit. However, the planetary/sub-stellar companion previously suggested to exist in this system is ruled out by our data. Our eclipse times show that the period decrease detected in NN Ser is continuing, with magnetic braking or a third body the only mechanisms able to explain this change. The planetary/sub-stellar companion previously suggested to exist in NN Ser is also ruled out by our data. Our precise eclipse times also lead to improved ephemerides for DE CVn and GK Vir. The width of a primary eclipse is directly related to the size of the secondary star and variations in the size of this star could be an indication of Applegate's mechanism or Wilson (starspot) depressions which can cause jitter in the O-C curves. We measure the width of primary eclipses for the systems NN Ser and GK Vir over several years but find no definitive variations in the radii of the secondary stars. However, our data are precise enough (Δ Rsec/Rsec < 10-5) to show the effects of Applegate's mechanism in the future. We find no evidence of Wilson depressions in either system. We also find tentative indications that flaring rates of the secondary stars depend on their mass rather than rotation rates.

  3. Coronal Element Abundances of the Post-Common Envelope Binary V471 Tauri with ASCA

    NASA Technical Reports Server (NTRS)

    Still, Martin; Hussain, Gaitee; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We report on ASCA observations of the coronally active companion star in the post-common envelope binary V471 Tau. While it would be prudent to check the following results with grating spectroscopy, we find that a single-temperature plasma model does not fit the data. Two temperature models with variable abundances indicate that Fe is underabundant compared to the Hyades photospheric mean, whereas, the high first ionization potential element Ne is overabundant. This is indicative of the inverse first ionization effect, believed to result from the fractionation of ionized material by the magnetic field in the upper atmosphere of the star. Evolutionary calculations indicate that there should be no peculiar abundances on the companion star resulting from the common envelope epoch. Indeed, we find no evidence for peculiar abundances, although uncertainties are high.

  4. Hα Emission in Post-Common-Envelope Binaries: White Dwarf Illumination vs. Chromospheric Activity

    NASA Astrophysics Data System (ADS)

    Spiewak, Renée; Pomerantz, B.; Strelnitski, V.; Walker, G. E.; Krajci, T.

    2013-01-01

    We revisit and augment the narrow-band photometry of two post-common-envelope close binary systems, V471 Tau and DE CVn, composed of a white dwarf (WD) and a red dwarf (RD). The photometry was accomplished using the 24-inch telescope of the Maria Mitchell Observatory and the 0.35-m telescope of the Astrokolkhoz Observatory. The filters allowed us to separate the temporal behavior of the Hα emission and the adjacent continuum. The latter shows in both binaries the well-known double wave with maxima around phases 0.25 and 0.75 and with an amplitude of several percent, which has been ascribed to the ellipsoidal shape of the red dwarf. We confirm our previous, preliminary conclusion that the phase curves of Hα emission in these two stars are different: in DE CVn, it is similar to the two-peak curve of the continuum, whereas in V471 Tau it has only one maximum - at phase 0.5. We interpret this difference by the difference in the WD temperature, previously determined as 34,500 and 8,000 K, for V471 Tau and DE CVn respectively. We show that the sub-WD area of the RD in V471 Tau intercepts enough ionizing photons from the hot WD to produce the observed Hα luminosity, whereas the relatively cold WD in DE CVn lacks several orders of magnitude in UV luminosity to create the observed Hα luminosity, which therefore should be ascribed to the chromospheric activity of the RD. This project was supported by NSF/REU grant AST-0851892 and the Nantucket Maria Mitchell Association.

  5. The post-common envelope central stars of the planetary nebulae Henize 2-155 and Henize 2-161

    NASA Astrophysics Data System (ADS)

    Jones, D.; Boffin, H. M. J.; Rodríguez-Gil, P.; Wesson, R.; Corradi, R. L. M.; Miszalski, B.; Mohamed, S.

    2015-08-01

    We present a study of Hen 2-155 and Hen 2-161, two planetary nebulae which bear striking morphological similarities to other planetary nebulae known to host close-binary central stars. Both central stars are revealed to be photometric variables while spectroscopic observations confirm that Hen 2-155 is host to a double-eclipsing, post-common-envelope system with an orbital period of 3h33m making it one of the shortest period binary central stars known. The observations of Hen 2-161 are found to be consistent with a post-common-envelope binary of period ~1 day. A detailed model of the central star of Hen 2-155 is produced, showing the nebular progenitor to be a hot, post-AGB remnant of approximately 0.62 M⊙, consistent with the age of the nebula, and the secondary star to be an M dwarf whose radius is almost twice the expected zero age main sequence radius for its mass. In spite of the small numbers, all main-sequence companions, of planetary nebulae central stars, to have had their masses and radii constrained by both photometric and spectroscopic observations have also been found to display this "inflation". The cause of the "inflation" is uncertain but is probably related to rapid accretion, immediately before the recent common-envelope phase, to which the star has not yet thermally adjusted. The chemical composition of both nebulae is also analysed, showing both to display elevated abundance discrepancy factors. This strengthens the link between elevated abundance discrepancy factors and close binarity in the nebular progenitor. Full Tables 2-5, and 7 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/580/A19

  6. Origin of apparent period variations in eclipsing post-common-envelope binaries

    NASA Astrophysics Data System (ADS)

    Zorotovic, M.; Schreiber, M. R.

    2013-01-01

    Context. Apparent period variations detected in several eclipsing, close-compact binaries are frequently interpreted as being caused by circumbinary giant planets. This interpretation raises the question of the origin of the potential planets that must have either formed in the primordial circumbinary disk, together with the host binary star, and survived its evolution into a close-compact binary or formed in a post-common-envelope circumbinary disk that remained bound to the post-common-envelope binary (PCEB). Aims: Here we combine current knowledge of planet formation and the statistics of giant planets around primordial and evolved binary stars with the theory of close-compact binary star evolution aiming to derive new constraints on possible formation scenarios. Methods: We compiled a comprehensive list of observed eclipsing PCEBs, estimated the fraction of systems showing apparent period variations, reconstructed the evolutionary history of the PCEBs, and performed binary population models of PCEBs to characterize their main sequence binary progenitors. We reviewed the currently available constraints on the fraction of PCEB progenitors that host circumbinary giant planets. Results: We find that the progenitors of PCEBs are very unlikely to be frequent hosts of giant planets (≲10 per cent), while the frequency of PCEBs with observed apparent period variations is very high (~90 per cent). Conclusions: The variations in eclipse timings measured in eclipsing PCEBs are probably not caused by first-generation planets that survived common-envelope evolution. The remaining options for explaining the observed period variations are second-generation planet formation or perhaps variations in the shape of a magnetically active secondary star. We suggest observational tests for both options. Appendix A is available in electronic form at http://www.aanda.org

  7. DOUBLE COMPACT OBJECTS. I. THE SIGNIFICANCE OF THE COMMON ENVELOPE ON MERGER RATES

    SciTech Connect

    Dominik, Michal; Belczynski, Krzysztof; Bulik, Tomasz; Fryer, Christopher; Holz, Daniel E.; Berti, Emanuele; Mandel, Ilya; O'Shaughnessy, Richard

    2012-11-01

    The last decade of observational and theoretical developments in stellar and binary evolution provides an opportunity to incorporate major improvements to the predictions from population synthesis models. We compute the Galactic merger rates for NS-NS, BH-NS, and BH-BH mergers with the StarTrack code. The most important revisions include updated wind mass-loss rates (allowing for stellar-mass black holes up to 80 M {sub Sun }), a realistic treatment of the common envelope phase (a process that can affect merger rates by 2-3 orders of magnitude), and a qualitatively new neutron star/black hole mass distribution (consistent with the observed {sup m}ass gap{sup )}. Our findings include the following. (1) The binding energy of the envelope plays a pivotal role in determining whether a binary merges within a Hubble time. (2) Our description of natal kicks from supernovae plays an important role, especially for the formation of BH-BH systems. (3) The masses of BH-BH systems can be substantially increased in the case of low metallicities or weak winds. (4) Certain combinations of parameters underpredict the Galactic NS-NS merger rate and can be ruled out. (5) Models incorporating delayed supernovae do not agree with the observed NS/BH 'mass gap', in accordance with our previous work. This is the first in a series of three papers. The second paper will study the merger rates of double compact objects as a function of redshift, star formation rate, and metallicity. In the third paper, we will present the detection rates for gravitational-wave observatories, using up-to-date signal waveforms and sensitivity curves.

  8. CHARACTERIZING THE COOL KOIs. V. KOI-256: A MUTUALLY ECLIPSING POST-COMMON ENVELOPE BINARY

    SciTech Connect

    Muirhead, Philip S.; Shporer, Avi; Becker, Juliette; Swift, Jonathan J.; Hinkley, Sasha; Pineda, J. Sebastian; Bottom, Michael; Baranec, Christoph; Riddle, Reed; Tendulkar, Shriharsh P.; Bui, Khanh; Vanderburg, Andrew; Lloyd, James P.; Fuller, Jim; Zhao, Ming; Howard, Andrew W.; Von Braun, Kaspar; Boyajian, Tabetha S.; Law, Nicholas; Ramaprakash, A. N.; and others

    2013-04-20

    We report that Kepler Object of Interest 256 (KOI-256) is a mutually eclipsing post-common envelope binary (ePCEB), consisting of a cool white dwarf (M{sub *} = 0.592 {+-} 0.089 M{sub Sun }, R{sub *} = 0.01345 {+-} 0.00091 R{sub Sun }, T{sub eff} = 7100 {+-} 700 K) and an active M3 dwarf (M{sub *} = 0.51 {+-} 0.16 M{sub Sun }, R{sub *} = 0.540 {+-} 0.014 R{sub Sun }, T{sub eff} = 3450 {+-} 50 K) with an orbital period of 1.37865 {+-} 0.00001 days. KOI-256 is listed as hosting a transiting planet-candidate by Borucki et al. and Batalha et al.; here we report that the planet-candidate transit signal is in fact the occultation of a white dwarf as it passes behind the M dwarf. We combine publicly-available long- and short-cadence Kepler light curves with ground-based measurements to robustly determine the system parameters. The occultation events are readily apparent in the Kepler light curve, as is spin-orbit synchronization of the M dwarf, and we detect the transit of the white dwarf in front of the M dwarf halfway between the occultation events. The size of the white dwarf with respect to the Einstein ring during transit (R{sub Ein} = 0.00473 {+-} 0.00055 R{sub Sun }) causes the transit depth to be shallower than expected from pure geometry due to gravitational lensing. KOI-256 is an old, long-period ePCEB and serves as a benchmark object for studying the evolution of binary star systems as well as white dwarfs themselves, thanks largely to the availability of near-continuous, ultra-precise Kepler photometry.

  9. TWO POSSIBLE CIRCUMBINARY PLANETS IN THE ECLIPSING POST-COMMON ENVELOPE SYSTEM NSVS 14256825

    SciTech Connect

    Almeida, L. A.; Jablonski, F.; Rodrigues, C. V.

    2013-03-20

    We present an analysis of eclipse timings of the post-common envelope binary NSVS 14256825, which is composed of an sdOB star and a dM star in a close orbit (P{sub orb} = 0.110374 days). High-speed photometry of this system was performed between 2010 July and 2012 August. Ten new mid-eclipse times were analyzed together with all available eclipse times in the literature. We revisited the (O - C) diagram using a linear ephemeris and verified a clear orbital period variation. On the assumption that these orbital period variations are caused by light travel time effects, the (O - C) diagram can be explained by the presence of two circumbinary bodies, even though this explanation requires a longer baseline of observations to be fully tested. The orbital periods of the best solution would be P{sub c} {approx} 3.5 years and P{sub d} {approx} 6.9 years. The corresponding projected semi-major axes would be a{sub c} sin i{sub c} {approx} 1.9 AU and a{sub d} sin i{sub d} {approx} 2.9 AU. The masses of the external bodies would be M{sub c} {approx} 2.9 M{sub Jupiter} and M{sub d} {approx} 8.1 M{sub Jupiter}, if we assume their orbits are coplanar with the close binary. Therefore NSVS 14256825 might be composed of a close binary with two circumbinary planets, though the orbital period variations is still open to other interpretations.

  10. The crowded magnetosphere of the post-common-envelope binary QS Virginis

    NASA Astrophysics Data System (ADS)

    Parsons, S. G.; Hill, C. A.; Marsh, T. R.; Gänsicke, B. T.; Watson, C. A.; Steeghs, D.; Dhillon, V. S.; Littlefair, S. P.; Copperwheat, C. M.; Schreiber, M. R.; Zorotovic, M.

    2016-05-01

    We present high-speed photometry and high-resolution spectroscopy of the eclipsing post-common-envelope binary QS Virginis (QS Vir). Our Ultraviolet and Visual Echelle Spectrograph (UVES) spectra span multiple orbits over more than a year and reveal the presence of several large prominences passing in front of both the M star and its white dwarf companion, allowing us to triangulate their positions. Despite showing small variations on a time-scale of days, they persist for more than a year and may last decades. One large prominence extends almost three stellar radii from the M star. Roche tomography reveals that the M star is heavily spotted and that these spots are long-lived and in relatively fixed locations, preferentially found on the hemisphere facing the white dwarf. We also determine precise binary and physical parameters for the system. We find that the 14 220 ± 350 K white dwarf is relatively massive, 0.782 ± 0.013 M⊙, and has a radius of 0.010 68 ± 0.000 07 R⊙, consistent with evolutionary models. The tidally distorted M star has a mass of 0.382 ± 0.006 M⊙ and a radius of 0.381 ± 0.003 R⊙, also consistent with evolutionary models. We find that the magnesium absorption line from the white dwarf is broader than expected. This could be due to rotation (implying a spin period of only ˜700 s), or due to a weak (˜100 kG) magnetic field, we favour the latter interpretation. Since the M star's radius is still within its Roche lobe and there is no evidence that it is overinflated, we conclude that QS Vir is most likely a pre-cataclysmic binary just about to become semidetached.

  11. Structure and Evolution of a Common Envelope in Simulations of Mass Transfer in Double White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Motl, Patrick M.

    2009-01-01

    We present evolutions of mass transfer in double white dwarf binaries with several different initial mass ratios. The systems have all been evolved in two limiting cases. In the polytropic evolutions, we in essence assume that the irreversible gain in entropy at the accretion shock is radiated away. In the second regime, the fluid is treated as an ideal gas and retains all of the thermal energy gained at the accretion shock. The later case is obviously more favorable to forming a common envelope about both the donor and accretor. In reality, at least some of the energy can escape and thus the ideal gas case will probably over-emphasize the tendency to form a common envelope. The simulations evolve an ideal fluid with an Eulerian hydrodynamics code. We simultaneously solve Poisson's equation for the gravitational potential. In this poster, we report on the thermal structure of the accreted material and also on the potentially interesting loss of mass and angular momentum from the binary system.

  12. Post common envelope binaries from SDSS. XI. The white dwarf mass distributions of CVs and pre-CVs

    NASA Astrophysics Data System (ADS)

    Zorotovic, M.; Schreiber, M. R.; Gänsicke, B. T.

    2011-12-01

    Context. We have known for a long time that many of the measured white dwarf (WD) masses in cataclysmic variables (CVs) significantly exceed the mean mass of single WDs. This was thought to be related to observational biases, but recent high-precision measurements of WD masses in a great number of CVs are challenging this interpretation. A crucial question in this context is whether the high WD masses seen among CVs are already imprinted in the mass distribution of their progenitors, i.e. among detached post-common-envelope binaries (PCEBs) that consist of a WD and a main-sequence star. Aims: We review the measured WD masses of CVs, determine the WD-mass distribution of an extensive sample of PCEBs that are representative for the progenitors of the current CV population (pre-CVs) and compare both distributions. Methods: We calculate the CV formation time of the PCEBs in our sample by determining the post common-envelope (CE) and the main-sequence evolution of the binary systems and define a pre-CV to be a PCEB that evolves into a semi-detached configuration with stable mass transfer within less than the age of the Galaxy. Possible observational biases affecting the WD-mass distribution for the pre-CV and the CV samples are discussed. Results: The mean WD mass among CVs is ⟨ Mwd ⟩ = 0.83 ± 0.23 M⊙, much larger than that found for pre-CVs, ⟨ Mwd ⟩ = 0.67 ± 0.21 M⊙. Selection effects cannot explain the high WD masses observed in CVs. We also note that compared to the predictions of binary-population models, the observed fraction of He-core WDs is small both among CVs (≤10%) and pre-CVs (≤17 ± 8%). Conclusions: We suggest two possible explanations for the high WD masses among CVs, both of which imply substantial revisions to the standard model of CV evolution: either most CVs have formed above the orbital-period gap (which requires a high WD mass to initiate stable mass transfer or a previous phase of thermal-timescale mass transfer), or the mass of

  13. Monte Carlo Simulations of the Post-Common-Envelope White-Dwarf Main-Sequence Binary Population

    SciTech Connect

    Camacho, Judit; Torres, Santiago; Garcia-Berro, Enrique; Schreiber, Matthias R.

    2010-12-22

    We present a detailed Monte Carlo simulator of the population of binary systems within the solar neighborhood. We have used the most up-to-date stellar evolutionary models, a complete treatment of the Roche lobe overflow episode, as well as a full implementation of the orbital evolution of the binary system. Preliminary results are presented for the population of white-dwarf main-sequence binaries, resulting from a common envelope episode. We also study the role played by the binding energy parameter, {lambda}, and by the common envelope efficiency, {alpha}{sub CE}. Finally, results are compared with the population of identified white-dwarf main-sequence binaries.

  14. The structure of common-envelope remnants

    NASA Astrophysics Data System (ADS)

    Hall, Philip D.

    2015-05-01

    evolved stars. These formulae can be used to better compute the outcome of common-envelope evolution with rapid evolution codes. We find that the new formulae are necessary for accurate predictions of the properties of post-common envelope systems. Finally, we use detailed remnant models of massive stars to investigate whether hydrogen may be retained after a common-envelope phase to the point of core-collapse and so be observable in supernovae. We find that this is possible and thus common-envelope evolution may contribute to the formation of Type IIb supernovae.

  15. Monte Carlo Population Synthesis of Post-common-envelope White Dwarf Binaries and Type Ia supernova Rate

    NASA Astrophysics Data System (ADS)

    Ablimit, Iminhaji; Maeda, Keiichi; Li, Xiang-Dong

    2016-07-01

    Binary population synthesis (BPS) studies provide a comprehensive way to understand the evolution of binaries and their end products. Close white dwarf (WD) binaries have crucial characteristics for examining the influence of unresolved physical parameters on binary evolution. In this paper, we perform Monte Carlo BPS simulations, investigating the population of WD/main-sequence (WD/MS) binaries and double WD binaries using a publicly available binary star evolution code under 37 different assumptions for key physical processes and binary initial conditions. We considered different combinations of the binding energy parameter (λ g: considering gravitational energy only; λ b: considering both gravitational energy and internal energy; and λ e: considering gravitational energy, internal energy, and entropy of the envelope, with values derived from the MESA code), CE efficiency, critical mass ratio, initial primary mass function, and metallicity. We find that a larger number of post-CE WD/MS binaries in tight orbits are formed when the binding energy parameters are set by λ e than in those cases where other prescriptions are adopted. We also determine the effects of the other input parameters on the orbital periods and mass distributions of post-CE WD/MS binaries. As they contain at least one CO WD, double WD systems that evolved from WD/MS binaries may explode as type Ia supernovae (SNe Ia) via merging. In this work, we also investigate the frequency of two WD mergers and compare it to the SNe Ia rate. The calculated Galactic SNe Ia rate with λ = λ e is comparable to the observed SNe Ia rate, ˜8.2 × 10‑5 yr‑1 – ˜4 × 10‑3 yr‑1 depending on the other BPS parameters, if a DD system does not require a mass ratio higher than ˜0.8 to become an SNe Ia. On the other hand, a violent merger scenario, which requires the combined mass of two CO WDs ≥ 1.6M ⊙ and a mass ratio >0.8, results in a much lower SNe Ia rate than is observed.

  16. Monte Carlo Population Synthesis of Post-common-envelope White Dwarf Binaries and Type Ia supernova Rate

    NASA Astrophysics Data System (ADS)

    Ablimit, Iminhaji; Maeda, Keiichi; Li, Xiang-Dong

    2016-07-01

    Binary population synthesis (BPS) studies provide a comprehensive way to understand the evolution of binaries and their end products. Close white dwarf (WD) binaries have crucial characteristics for examining the influence of unresolved physical parameters on binary evolution. In this paper, we perform Monte Carlo BPS simulations, investigating the population of WD/main-sequence (WD/MS) binaries and double WD binaries using a publicly available binary star evolution code under 37 different assumptions for key physical processes and binary initial conditions. We considered different combinations of the binding energy parameter (λ g: considering gravitational energy only; λ b: considering both gravitational energy and internal energy; and λ e: considering gravitational energy, internal energy, and entropy of the envelope, with values derived from the MESA code), CE efficiency, critical mass ratio, initial primary mass function, and metallicity. We find that a larger number of post-CE WD/MS binaries in tight orbits are formed when the binding energy parameters are set by λ e than in those cases where other prescriptions are adopted. We also determine the effects of the other input parameters on the orbital periods and mass distributions of post-CE WD/MS binaries. As they contain at least one CO WD, double WD systems that evolved from WD/MS binaries may explode as type Ia supernovae (SNe Ia) via merging. In this work, we also investigate the frequency of two WD mergers and compare it to the SNe Ia rate. The calculated Galactic SNe Ia rate with λ = λ e is comparable to the observed SNe Ia rate, ∼8.2 × 10‑5 yr‑1 – ∼4 × 10‑3 yr‑1 depending on the other BPS parameters, if a DD system does not require a mass ratio higher than ∼0.8 to become an SNe Ia. On the other hand, a violent merger scenario, which requires the combined mass of two CO WDs ≥ 1.6M ⊙ and a mass ratio >0.8, results in a much lower SNe Ia rate than is observed.

  17. COMMON ENVELOPE: ENTHALPY CONSIDERATION

    SciTech Connect

    Ivanova, N.; Chaichenets, S.

    2011-04-20

    In this Letter, we discuss a modification to the criterion for the common envelope (CE) event to result in envelope dispersion. We emphasize that the current energy criterion for the CE phase is not sufficient for an instability of the CE, nor for an ejection. However, in some cases, stellar envelopes undergo stationary mass outflows, which are likely to occur during the slow spiral-in stage of the CE event. We propose the condition for such outflows, in a manner similar to the currently standard {alpha}{sub CE}{lambda}-prescription but with an addition of P/{rho} term in the energy balance equation, accounting therefore for the enthalpy of the envelope rather than merely the gas internal energy. This produces a significant correction, which might help to dispense with an unphysically high value of energy efficiency parameter during the CE phase, currently required in the binary population synthesis studies to make the production of low-mass X-ray binaries with a black hole companion to match the observations.

  18. A carbon dwarf wearing a Necklace: first proof of accretion in a post-common-envelope binary central star of a planetary nebula with jets

    NASA Astrophysics Data System (ADS)

    Miszalski, Brent; Boffin, Henri M. J.; Corradi, Romano L. M.

    2013-01-01

    The formation of collimated outflows or jets in planetary nebulae (PNe) is not well understood. There is no evidence for active accretion discs in PNe, making it difficult to decide which of the several proposed jet formation scenarios may be correct. A handful of wide binary central stars of PNe are known to have accreted carbon and slow neutron capture (s-process) enhanced material, the immediate progenitors of barium stars; however, no close binary analogues are known to have passed through a common-envelope (CE) phase. Here we present spectroscopy of the Necklace taken near light-curve minimum that for the first time reveals a carbon-rich (C/O > 1) companion, a carbon dwarf, in a post-CE central star. As unevolved stars do not produce carbon, the chemical enhancement of the secondary can only be explained by accretion from the primary. Accretion most likely happened prior to the CE phase via wind accretion as not enough material can be accreted during the short CE phase. The pair of jets in the Necklace, which are observed to be older than the PN, are therefore likely to have been launched from an accretion disc around the companion during this early accretion phase. This discovery adds significant weight to the emerging scenario that jets in post-CE PNe are primarily launched by an accretion disc around a main-sequence companion before the CE phase.

  19. THE WIRED SURVEY. III. AN INFRARED EXCESS AROUND THE ECLIPSING POST-COMMON ENVELOPE BINARY SDSS J030308.35+005443.7

    SciTech Connect

    Debes, John H.; Hoard, D. W.; Farihi, Jay; Wachter, Stefanie; Leisawitz, David T.; Cohen, Martin

    2012-11-01

    We present the discovery with WISE of a significant infrared excess associated with the eclipsing post-common envelope binary SDSS J030308.35+005443.7, the first excess discovered around a non-interacting white dwarf+main-sequence M dwarf binary. The spectral energy distribution of the white dwarf+M dwarf companion shows significant excess longward of 3 {mu}m. A T {sub eff} of 8940 K for the white dwarf is consistent with a cooling age >2 Gyr, implying that the excess may be due to a recently formed circumbinary dust disk of material that extends from the tidal truncation radius of the binary at 1.96 R {sub Sun} out to <0.8 AU, with a total mass of {approx}10{sup 20} g. We also construct WISE and follow-up ground-based near-infrared light curves of the system and find variability in the K band that appears to be in phase with ellipsoidal variations observed in the visible. The presence of dust might be due to (1) material being generated by the destruction of small rocky bodies that are being perturbed by an unseen planetary system or (2) dust condensing from the companion's wind. The high inclination of this system and the presence of dust make it an attractive target for M dwarf transit surveys and long-term photometric monitoring.

  20. The quest for companions to post-common envelope binaries. IV. The 2:1 mean-motion resonance of the planets orbiting NN Serpentis

    NASA Astrophysics Data System (ADS)

    Beuermann, K.; Dreizler, S.; Hessman, F. V.

    2013-07-01

    We present 69 new mid-eclipse times of the young post-common envelope binary (PCEB) NN Ser, which was previously suggested to possess two circumbinary planets. We have interpreted the observed eclipse-time variations in terms of the light-travel time effect caused by two planets, exhaustively covering the multi-dimensional parameter space by fits in the two binary and ten orbital parameters. We supplemented the fits by stability calculations for all models with an acceptable χ2. An island of secularly stable 2:1 resonant solutions exists, which coincides with the global χ2 minimum. Our best-fit stable solution yields current orbital periods Po = 15.47 yr and Pi = 7.65 yr and eccentricities eo = 0.14 and ei = 0.22 for the outer and inner planets, respectively. The companions qualify as giant planets, with masses of 7.0 MJup and 1.7 MJup for the case of orbits coplanar with that of the binary. The two-planet model that starts from the present system parameters has a lifetime greater than 108 yr, which significantly exceeds the age of NN Ser of 106 yr as a PCEB. The resonance is characterized by libration of the resonant variable Θ1 and circulation of , the difference between the arguments of periapse of the two planets. No stable nonresonant solutions were found, and the possibility of a 5:2 resonance suggested previously by us is now excluded at the 99.3% confidence level. Table 1 is available in electronic form at http://www.aanda.org

  1. Search with UVES and X-Shooter for signatures of the low-mass secondary in the post common-envelope binary AA Doradus

    NASA Astrophysics Data System (ADS)

    Hoyer, D.; Rauch, T.; Werner, K.; Hauschildt, P. H.; Kruk, J. W.

    2015-06-01

    Context. AA Dor is a close, totally eclipsing, post common-envelope binary with an sdOB-type primary star and an extremely low-mass secondary star, located close to the mass limit of stable central hydrogen burning. Within error limits, it may either be a brown dwarf or a late M-type dwarf. Aims: We aim to extract the secondary's contribution to the phase-dependent composite spectra. The spectrum and identified lines of the secondary decide on its nature. Methods: In January 2014, we measured the phase-dependent spectrum of AA Dor with X-Shooter over one complete orbital period. Since the secondary's rotation is presumable synchronized with the orbital period, its surface strictly divides into a day and night side. Therefore, we may obtain the spectrum of its cool side during its transit and of its hot, irradiated side close to its occultation. We developed the Virtual Observatory (VO) tool TLISA to search for weak lines of a faint companion in a binary system. We successfully applied it to the observations of AA Dor. Results: We identified 53 spectral lines of the secondary in the ultraviolet-blue, visual, and near-infrared X-Shooter spectra that are strongest close to its occultation. We identified 57 (20 additional) lines in available Ultraviolet and Visual Echelle Spectrograph (UVES) spectra from 2001. The lines are mostly from C ii-iii and O ii, typical for a low-mass star that is irradiated and heated by the primary. We verified the orbital period of P = 22 597.033201 ± 0.00007 s and determined the orbital velocity K_sec = 232.9+16.6-6.5 km s-1 of the secondary. The mass of the secondary is M_sec = 0.081+0.018-0.010 M_⊙ and, hence, it is not possible to reliably determine a brown dwarf or an M-type dwarf nature. Conclusions: Although we identified many emission lines of the secondary's irradiated surface, the resolution and signal-to-noise ratio of our UVES and X-Shooter spectra are not good enough to extract a good spectrum of the secondary

  2. Common Envelope and the Binding Energy Consideration

    NASA Astrophysics Data System (ADS)

    Irawati, P.; Mahasena, P.

    2014-08-01

    We report the results of our study on the common-envelope phase of the cataclysmic variables. We are investigating the role of additional energies, such as recombination energy and internal energy, in expelling the envelope of the primary star. In this work, we use the TWIN stellar evolution code which can evolve both stars in binary simultaneously. We analysed the energies involved by considering the binding energy of the core at the onset of the common envelope phase. The core of the primary is calculated using the hydrogen-exhausted layer with 10% hydrogen fraction. Our preliminary result shows that the internal energy plays a significant role while the recombination energy has only a small contribution to the energy budget of the cataclysmic variable evolution.

  3. Asymmetric Accretion Flows within a Common Envelope

    NASA Astrophysics Data System (ADS)

    MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2015-04-01

    This paper examines flows in the immediate vicinity of stars and compact objects dynamically inspiralling within a common envelope (CE). Flow in the vicinity of the embedded object is gravitationally focused, leading to drag and potentially to gas accretion. This process has been studied numerically and analytically in the context of Hoyle-Lyttleton accretion (HLA). Yet, within a CE, accretion structures may span a large fraction of the envelope radius, and in so doing sweep across a substantial radial gradient of density. We quantify these gradients using detailed stellar evolution models for a range of CE encounters. We provide estimates of typical scales in CE encounters that involve main sequence stars, white dwarfs, neutron stars, and black holes with giant-branch companions of a wide range of masses. We apply these typical scales to hydrodynamic simulations of three-dimensional HLA with an upstream density gradient. This density gradient breaks the symmetry that defines HLA flow, and imposes an angular momentum barrier to accretion. Material that is focused into the vicinity of the embedded object thus may not be able to accrete. As a result, accretion rates drop dramatically, by one to two orders of magnitude, while drag rates are only mildly affected. We provide fitting formulae to the numerically derived rates of drag and accretion as a function of the density gradient. The reduced ratio of accretion to drag suggests that objects that can efficiently gain mass during CE evolution, such as black holes and neutron stars, may grow less than implied by the HLA formalism.

  4. Common envelope events with low-mass giants: understanding the energy budget

    NASA Astrophysics Data System (ADS)

    Nandez, J. L. A.; Ivanova, N.

    2016-08-01

    Common envelope events are important interactions between two binary stars that lead to the formation of close binary systems. We present here a systematic three-dimensional study in which we model common envelope events with low-mass giant donors. The results allow us to revise the energy formalism that is usually used to determine common envelope event outcomes. We show that the energy budget for this type of system should include the recombination energy, and that it also must take into account that a significant fraction of the released orbital energy is taken away by the ejecta. We provide three ways in which our results can be used by binary population synthesis studies: a relation that links the observed post-common envelope binary with the initial binary parameters, a fitting formula for the $\\alpha_{\\rm ce}\\lambda$ parameter of the standard energy formalism, and a revised energy formalism that takes into account both the recombination energy and the energy that is taken away by the ejecta.

  5. Common envelope events with low-mass giants: understanding the energy budget

    NASA Astrophysics Data System (ADS)

    Nandez, J. L. A.; Ivanova, N.

    2016-08-01

    Common envelope events are important interactions between two binary stars that lead to the formation of close binary systems. We present here a systematic three-dimensional study in which we model common envelope events with low-mass giant donors. The results allow us to revise the energy formalism that is usually used to determine common envelope event outcomes. We show that the energy budget for this type of system should include the recombination energy, and that it also must take into account that a significant fraction of the released orbital energy is taken away by the ejecta. We provide three ways in which our results can be used by binary population synthesis studies: a relation that links the observed post-common envelope binary with the initial binary parameters, a fitting formula for the αceλ parameter of the standard energy formalism, and a revised energy formalism that takes into account both the recombination energy and the energy that is taken away by the ejecta.

  6. Common envelope events with low-mass giants: understanding the energy budget

    NASA Astrophysics Data System (ADS)

    Nandez, J. L. A.; Ivanova, N.

    2016-05-01

    Common envelope events are important interactions between two binary stars that lead to the formation of close binary systems. We present here a systematic three-dimensional study in which we model common envelope events with low-mass giant donors. The results allow us to revise the energy formalism that is usually used to determine common envelope event outcomes. We show that the energy budget for this type of system should include the recombination energy, and that it also must take into account that a significant fraction of the released orbital energy is taken away by the ejecta. We provide three ways in which our results can be used by binary population synthesis studies: a relation that links the observed post-common envelope binary with the initial binary parameters, a fitting formula for the αceλ parameter of the standard energy formalism, and a revised energy formalism that takes into account both the recombination energy and the energy that is taken away by the ejecta.

  7. Empirical Constraints on Common Envelope Evolution in Wide Binaries

    NASA Astrophysics Data System (ADS)

    Geller, Aaron M.; Hurley, J. R.; Mathieu, R. D.

    2012-01-01

    If a giant star in a binary overfills its Roche lobe, the giant's convective envelope may respond by expanding faster than its Roche lobe, transferring mass on a dynamical time scale, and creating a common envelope (CE) that engulfs both stars. Orbital energy may then be transferred from the binary to the envelope, which can shrink the orbit and drive away the material, leaving behind a detached system containing the white dwarf core of the giant. Such a CE event is thought to be critical for explaining certain populations of exotic stars (e.g., cataclysmic variables). Yet the application of CE evolution to binary population synthesis and N-body or Monte Carlo star cluster models requires many poorly constrained assumptions, which may lead to unphysical evolutionary paths. In fact, we find that such fictitious systems are created regularly within our N-body models of the old (7 Gyr) open cluster NGC 188. Most notably, the model predicts a population of post-CE long-period ( 1000 days) circular solar-type main sequence - white dwarf binaries, that are not present in our observations of the true binaries in NGC 188, or any other solar-type binary population in the literature (in star clusters or in the field). The absence of such post-CE systems in real binary populations places important limits on parameters used in most models of CE evolution, and may suggest that more binaries undergo stable mass transfer than has previously been assumed. We discuss how various solutions to this problem would impact other observable stellar populations, including cataclysmic variables, symbiotic stars and blue stragglers.

  8. ON THE BINDING ENERGY PARAMETER {lambda} OF COMMON ENVELOPE EVOLUTION

    SciTech Connect

    Xu Xiaojie; Li Xiangdong

    2010-06-10

    The binding energy parameter {lambda} plays an important role in common envelope evolution. Previous works have already pointed out that {lambda} varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter {lambda} for both Population I and Population II stars of masses 1-20 M {sub sun}, taking into account the contribution from the internal energy of stellar matter. We present fitting formulae for {lambda} that can be incorporated into future population synthesis investigations. We also briefly discuss the possible applications of the results in binary evolutions.

  9. On the Binding Energy Parameter λ of Common Envelope Evolution

    NASA Astrophysics Data System (ADS)

    Xu, Xiao-Jie; Li, Xiang-Dong

    2010-06-01

    The binding energy parameter λ plays an important role in common envelope evolution. Previous works have already pointed out that λ varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter λ for both Population I and Population II stars of masses 1-20 M sun, taking into account the contribution from the internal energy of stellar matter. We present fitting formulae for λ that can be incorporated into future population synthesis investigations. We also briefly discuss the possible applications of the results in binary evolutions.

  10. COMMON ENVELOPE EVOLUTION LEADING TO SUPERNOVAE WITH DENSE INTERACTION

    SciTech Connect

    Chevalier, Roger A.

    2012-06-10

    A variety of supernova events, including Type IIn supernovae and ultraluminous supernovae, appear to have lost up to solar masses of their envelopes in tens to hundreds of years leading up to the explosion. In order to explain the close timing of the mass loss and supernova events, we explore the possibility that the mass loss is driven by common envelope evolution of a compact object (neutron star or black hole) in the envelope of a massive star and the supernova is triggered by the inspiral of the compact object to the central core of the companion star. The expected rate of such events is smaller than the observed rate of Type IIn supernovae but the rates may agree within the uncertainties. The mass loss velocity is related to the escape velocity from the common envelope system and is comparable to the observed velocity of hundreds of kilometers per second in Type IIn events. The mass loss is expected to be denser near the equatorial plane of the binary system and there is good evidence that the circumstellar media in Type IIn supernovae are asymmetric. Some of these supernova types show evidence for energies in excess of the canonical 10{sup 51} erg, which might be the result of explosions from rapid accretion onto a compact object through a disk.

  11. The binding energy parameter for common envelope evolution

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Jia, Kun; Li, Xiang-Dong

    2016-08-01

    The binding energy parameter λ plays a vital role in common envelope evolution. Though it is well known that λ takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most population synthesis calculations. We have systematically calculated the values of λ for stars of masses 1 – 60 M ⊙ by use of an updated stellar evolution code, taking into account the contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by Ivanova. A new kind of λ with an enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of λ, which can be used in future population synthesis studies.

  12. DUST FORMATION IN THE EJECTA OF COMMON ENVELOPE SYSTEMS

    SciTech Connect

    Lue Guoliang; Zhu Chunhua; Podsiadlowski, Philipp

    2013-05-10

    The material that is ejected in a common-envelope (CE) phase in a close binary system provides an ideal environment for dust formation. By constructing a simple toy model to describe the evolution of the density and the temperature of CE ejecta and using the AGBDUST code to model dust formation, we show that dust can form efficiently in this environment. The actual dust masses produced in the CE ejecta depend strongly on their temperature and density evolution. We estimate the total dust masses produced by CE evolution by means of a population synthesis code and show that, compared to dust production in asymptotic giant branch stars, the dust produced in CE ejecta may be quite significant and could even dominate under certain circumstances.

  13. Considerations on the role of fall-back discs in the final stages of the common envelope binary interaction

    NASA Astrophysics Data System (ADS)

    Kuruwita, Rajika L.; Staff, Jan; De Marco, Orsola

    2016-09-01

    The common envelope interaction is thought to be the gateway to all evolved compact binaries and mergers. Hydrodynamic simulations of the common envelope interaction between giant stars and their companions are restricted to the dynamical, fast, in-spiral phase. They find that the giant envelope is lifted during this phase, but remains mostly bound to the system. At the same time, the orbital separation is greatly reduced, but in most simulations it levels off at values larger than measured from observations. We conjectured that during the post-in-spiral phase the bound envelope gas will return to the system. Using hydrodynamic simulations, we generate initial conditions for our simulation that result in a fall-back disc with total mass and angular momentum in line with quantities from the simulations of Passy et al. We find that the simulated fall-back event reduces the orbital separation efficiently, but fails to unbind the gas before the separation levels off once again. We also find that more massive fall-back discs reduce the orbital separation more efficiently, but the efficiency of unbinding remains invariably very low. From these results we deduce that unless a further energy source contributes to unbinding the envelope (such as was recently tested by Nandez et al.), all common envelope interactions would result in mergers. On the other hand, additional energy sources are unlikely to help, on their own, to reduce the orbital separation. We conclude by discussing our dynamical fall-back event in the context of a thermally regulated post-common envelope phase.

  14. Constraints on common envelope magnetic fields from observations of jets in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Tocknell, James; De Marco, Orsola; Wardle, Mark

    2014-04-01

    The common envelope (CE) interaction describes the swallowing of a nearby companion by a growing, evolving star. CEs that take place during the asymptotic giant branch phase of the primary may lead to the formation of a planetary nebula (PN) with a post-CE close binary in the middle. We have used published observations of masses and kinematics of jets in four post-CE PN to infer physical characteristics of the CE interaction. In three of the four systems studied, Abell 63, ETHOS 1 and the Necklace PN, the kinematics indicate that the jets were launched a few thousand years before the CE and we favour a scenario where this happened before Roche lobe overflow, although better models of wind accretion and wind Roche lobe overflow are needed. The magnetic fields inferred to launch pre-CE jets are of the order of a few gauss. In the fourth case, NGC 6778, the kinematics indicate that the jets were launched about 3000 yr after the CE interaction. Magnetic fields of the order of a few hundreds to a few thousands gauss are inferred in this case, approximately in line with predictions of post-CE magnetic fields. However, we remark that in the case of this system, we have not been able to find a reasonable scenario for the formation of the two jet pairs observed: the small orbital separation may preclude the formation of even one accretion disc able to supply the necessary accretion rate to cause the observed jets.

  15. ON THE ACCRETION-FED GROWTH OF NEUTRON STARS DURING COMMON ENVELOPE

    SciTech Connect

    MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2015-01-01

    This paper models the orbital inspiral of a neutron star (NS) through the envelope of its giant-branch companion during a common envelope (CE) episode. These CE episodes are necessary to produce close pairs of NSs that can inspiral and merge due to gravitational wave losses in less than a Hubble time. Because cooling by neutrinos can be very efficient, NSs have been predicted to accumulate significant mass during CE events, perhaps enough to lead them to collapse to black holes. We revisit this conclusion with the additional consideration of CE structure, particularly density gradients across the embedded NS's accretion radius. This work is informed by our recent numerical simulations that find that the presence of a density gradient strongly limits accretion by imposing a net angular momentum to the flow around the NS. Our calculations suggest that NSs should survive CE encounters. They accrete only modest amounts of envelope material, ≲ 0.1 M {sub ☉}, which is broadly consistent with mass determinations of double NS binaries. With less mass gain, NSs must spiral deeper to eject their CE, leading to a potential increase in mergers. The survival of NSs in CE events has implications for the formation mechanism of observed double NS binaries, as well as for predicted rates of NS binary gravitational wave inspirals and their electromagnetic counterparts.

  16. Formation of high-field magnetic white dwarfs from common envelopes.

    PubMed

    Nordhaus, Jason; Wellons, Sarah; Spiegel, David S; Metzger, Brian D; Blackman, Eric G

    2011-02-22

    The origin of highly magnetized white dwarfs has remained a mystery since their initial discovery. Recent observations indicate that the formation of high-field magnetic white dwarfs is intimately related to strong binary interactions during post-main-sequence phases of stellar evolution. If a low-mass companion, such as a planet, brown dwarf, or low-mass star, is engulfed by a post-main-sequence giant, gravitational torques in the envelope of the giant lead to a reduction of the companion's orbit. Sufficiently low-mass companions in-spiral until they are shredded by the strong gravitational tides near the white dwarf core. Subsequent formation of a super-Eddington accretion disk from the disrupted companion inside a common envelope can dramatically amplify magnetic fields via a dynamo. Here, we show that these disk-generated fields are sufficiently strong to explain the observed range of magnetic field strengths for isolated, high-field magnetic white dwarfs. A higher-mass binary analogue may also contribute to the origin of magnetar fields. PMID:21300910

  17. Formation of high-field magnetic white dwarfs from common envelopes

    PubMed Central

    Nordhaus, Jason; Wellons, Sarah; Spiegel, David S.; Metzger, Brian D.; Blackman, Eric G.

    2011-01-01

    The origin of highly magnetized white dwarfs has remained a mystery since their initial discovery. Recent observations indicate that the formation of high-field magnetic white dwarfs is intimately related to strong binary interactions during post-main-sequence phases of stellar evolution. If a low-mass companion, such as a planet, brown dwarf, or low-mass star, is engulfed by a post-main-sequence giant, gravitational torques in the envelope of the giant lead to a reduction of the companion’s orbit. Sufficiently low-mass companions in-spiral until they are shredded by the strong gravitational tides near the white dwarf core. Subsequent formation of a super-Eddington accretion disk from the disrupted companion inside a common envelope can dramatically amplify magnetic fields via a dynamo. Here, we show that these disk-generated fields are sufficiently strong to explain the observed range of magnetic field strengths for isolated, high-field magnetic white dwarfs. A higher-mass binary analogue may also contribute to the origin of magnetar fields. PMID:21300910

  18. Constraints on Common Envelope Magnetic Fields from Observations of Jets in Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    De Marco, Orsola; Tocknell, J.; Wardle, M.

    2014-01-01

    The common envelope (CE) interaction describes the swallowing of a nearby companion by a growing, evolving star. CEs that take place during the asymptotic giant branch phase of the primary and may lead to the formation of a planetary nebula (PN) with a post-CE close binary in the middle. We have used published observations of masses and kinematics of jets in four post-CE PN to infer physical characteristics of the CE interaction. In three of the four systems studied, Abell 63, ETHOS 1 and the Necklace PN, the kinematics indicate that the jets were launched a few thousand years before the CE and we favour a scenario where this happened before Roche lobe overflow, although better models of wind accretion and wind Roche lobe overflow are needed. The magnetic fields inferred to launch pre-CE jets are of the order of a few Gauss. In the fourth case, NGC 6778, the kinematics indicate that the jets were launched about 3000 years after the CE interaction. Magnetic fields of the order of a few hundreds to a few thousands Gauss are inferred in this case, approximately in line with predictions of post-CE magnetic fields. However, we remark that in the case of this system, we cannot find a reasonable scenario for the formation of the two jet pairs observed: the small orbital separation would preclude the formation of even one accretion disk able to supply the necessary accretion rate to cause the observed jets. Additional and improved observations of post-CE PN will provide a powerful tool to constrain the CE interaction.

  19. Use HMXB offsets to constrain the natal kicks and common envelope efficinecy

    NASA Astrophysics Data System (ADS)

    Zuo, Zhaoyu

    2015-08-01

    Using an up-to-date evolutionary population synthesis code, we have calculated the spatial offsets of high mass X-ray binaries and their correlation to the luminosities. Parameters affecting the orbit and system velocity of a binary are examined systematically. From the calculated results we find that the common envelope efficiency is possibly around ~0.8-1.0 and make several constraints on the natal kicks.

  20. Accretion and activity on the post-common-envelope binary RR Caeli

    NASA Astrophysics Data System (ADS)

    Ribeiro, T.; Baptista, R.; Kafka, S.; Dufour, P.; Gianninas, A.; Fontaine, G.

    2013-08-01

    Context. Current scenarios for the evolution of interacting close binaries - such as cataclysmic variables (CVs) - rely mainly on our understanding of low-mass star angular momentum loss (AML) mechanisms. The coupling of stellar wind with its magnetic field, i.e., magnetic braking, is the most promising mechanism believed to drive AML in these stars. There are basically two properties thought to drive magnetic braking: the stellar magnetic field and the stellar wind. Understanding the mechanisms that drive AML therefore requires a comprehensive understanding of these two properties as well. Aims. RR Cae is a well-known nearby (d = 20 pc) eclipsing DA+M binary with an orbital period of P = 7.29 h. The system harbors a metal-rich cool DA white dwarf (WD) and a highly active M-dwarf locked in synchronous rotation. The metallicity of the WD suggests that wind accretion is taking place, which provides a good opportunity to obtain the mass-loss rate of the M-dwarf component. We aim to reach a better understanding of the AML mechanisms in close binaries by characterizing the relevant properties of the M-dwarf component of this system. Methods. We analyzed multi-epoch time-resolved high-resolution spectra of RR Cae in search for traces of magnetic activity and accretion. We selected a number of well-known chromospheric activity indicators and studied their phase-dependence and long-term behavior. Indirect-imaging tomographic techniques were also applied to provide the surface brightness distribution of the magnetically active M-dwarf. The blue part of the spectrum was modeled using a state-of-the-art atmosphere model to constrain the WD properties and its metal enrichment. The latter was used to improve the determination of the mass-accretion rate from the M-dwarf wind. Results. Doppler imaging of the M-dwarf component of RR Cae reveals a polar feature similar to those observed in fast-rotating solar-type stars. Analysis of tomographic reconstruction of the Hα emission line reveals two components, one traces the motion of the M dwarf and is generated by chromospheric activity, while the other clearly follows the motion of the WD. The presence of metals in the WD spectrum suggests that this component arises from accretion of the M-dwarf wind. A model fit to the WD spectrum provides Teff = (7260 ± 250) K and log g = (7.8 ± 0.1) dex with a metallicity of (log [X/X⊙]) = (-2.8Â ± 0.1) dex. This maps into a mass-accretion rate of M⊙acc = (7 ± 2) × 10-16M⊙ yr-1 onto the surface of the WD. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 076.D-0142.

  1. The quest for companions to post-common envelope binaries. III. A reexamination of HW Virginis

    NASA Astrophysics Data System (ADS)

    Beuermann, K.; Dreizler, S.; Hessman, F. V.; Deller, J.

    2012-07-01

    We report new mid-eclipse times of the short-period sdB/dM binary HW Virginis, which differ substantially from the times predicted by a previous model. The proposed orbits of the two planets in that model are found to be unstable. We present a new secularly stable solution, which involves two companions orbiting HW Vir with periods of 12.7 yr and 55 ± 15 yr. For orbits coplanar with the binary, the inner companion is a giant planet with mass M3 sin i3 ≃ 14 MJup and the outer one a brown dwarf or low-mass star with a mass of M4 sin i4 = 30-120 MJup. Using the mercury6 code, we find that such a system would be stable over more than 107 yr, in spite of the sizeable interaction. Our model fits the observed eclipse-time variations by the light-travel time effect alone, without invoking any additional process, and provides support for the planetary hypothesis of the eclipse-time variations in close binaries. The signature of non-Keplerian orbits may be visible in the data.

  2. Photometry of the post-common-envelope binary PG 0308+096

    NASA Astrophysics Data System (ADS)

    Somers, M. W.; Lockley, J. J.; Naylor, T.; Wood, Janet H.

    1996-06-01

    We present R- and H-band photometry of PG 0308+096. We demonstrate that the orbital modulation is consistent with that of a dwarf M star heated by a DA white dwarf within the constraints given by the kinematic parameters. By fitting the photometry with an irradiation model we determine that the radius of the white dwarf is 0.019<=R_wd<=0.026 R_ (90 per cent confidence). In order to derive these limits, we have developed a fitting procedure that takes account of the external constraints derived from the spectroscopic analysis by Saffer et al. We determine that the period of the system is 0.286654+/-0.00000078d, which is one of the cycle count aliases considered by Saffer et al. We show that the Hα emission from the surface of the red star can be modelled as either optically thick or thin, but in the latter case the red dwarf must have intrinsic emission.

  3. Hydrodynamic Moving-mesh Simulations of the Common Envelope Phase in Binary Stellar Systems

    NASA Astrophysics Data System (ADS)

    Ohlmann, Sebastian T.; Röpke, Friedrich K.; Pakmor, Rüdiger; Springel, Volker

    2016-01-01

    The common envelope (CE) phase is an important stage in binary stellar evolution. It is needed to explain many close binary stellar systems, such as cataclysmic variables, SN Ia progenitors, or X-ray binaries. To form the resulting close binary, the initial orbit has to shrink, thereby transferring energy to the primary giant's envelope that is hence ejected. The details of this interaction, however, are still not understood. Here, we present new hydrodynamic simulations of the dynamical spiral-in forming a CE system. We apply the moving-mesh code arepo to follow the interaction of a 1{M}⊙ compact star with a 2{M}⊙ red giant possessing a 0.4{M}⊙ core. The nearly Lagrangian scheme combines advantages of smoothed particle hydrodynamics and traditional grid-based hydrodynamic codes and allows us to capture also small flow features at high spatial resolution. Our simulations reproduce the initial transfer of energy and angular momentum from the binary core to the envelope by spiral shocks seen in previous studies, but after about 20 orbits a new phenomenon is observed. Large-scale flow instabilities are triggered by shear flows between adjacent shock layers. These indicate the onset of turbulent convection in the CE, thus altering the transport of energy on longer timescales. At the end of our simulation, only 8% of the envelope mass is ejected. The failure to unbind the envelope completely may be caused by processes on thermal timescales or unresolved microphysics.

  4. Masses and Envelope Binding Energies of Primary Stars at the Onset of a Common Envelope

    NASA Astrophysics Data System (ADS)

    van der Sluys, Marc; Politano, Michael; Taam, Ronald E.

    2010-12-01

    We present basic properties of primary stars that initiate a common envelope (CE) in a binary, while on the giant branch. We use the population-synthesis code described in Politano et al. [1] and follow the evolution of a population of binary stars up to the point where the primary fills its Roche lobe and initiates a CE. We then collect the properties of each system, in particular the donor mass and the binding energy of the donor's envelope, which are important for the treatment of a CE. We find that for most CEs, the donor mass is sufficiently low to define the core-envelope boundary reasonably well. We compute the envelope-structure parameter λenv from the binding energy and compare its distribution to typical assumptions that are made in population-synthesis codes. We conclude that λenv varies appreciably and that the assumption of a constant value for this parameter results in typical errors of 20-50%. In addition, such an assumption may well result in the implicit assumption of unintended and/or unphysical values for the CE parameter αCE. Finally, we discuss accurate existing analytic fits for the envelope binding energy, which make these oversimplified assumptions for λenv, and the use of λenv in general, unnecessary.

  5. AN AMR STUDY OF THE COMMON-ENVELOPE PHASE OF BINARY EVOLUTION

    SciTech Connect

    Ricker, Paul M.; Taam, Ronald E. E-mail: r-taam@northwestern.edu

    2012-02-10

    The hydrodynamic evolution of the common-envelope (CE) phase of a low-mass binary composed of a 1.05 M{sub Sun} red giant and a 0.6 M{sub Sun} companion has been followed for five orbits of the system using a high-resolution method in three spatial dimensions. During the rapid inspiral phase, the interaction of the companion with the red giant's extended atmosphere causes about 25% of the CE to be ejected from the system, with mass continuing to be lost at the end of the simulation at a rate {approx}2 M{sub Sun} yr{sup -1}. In the process the resulting loss of angular momentum and energy reduces the orbital separation by a factor of seven. After this inspiral phase the eccentricity of the orbit rapidly decreases with time. The gravitational drag dominates hydrodynamic drag at all times in the evolution, and the commonly used Bondi-Hoyle-Lyttleton prescription for estimating the accretion rate onto the companion significantly overestimates the true rate. On scales comparable to the orbital separation, the gas flow in the orbital plane in the vicinity of the two cores is subsonic with the gas nearly corotating with the red giant core and circulating about the red giant companion. On larger scales, 90% of the outflow is contained within 30 Degree-Sign of the orbital plane, and the spiral shocks in this material leave an imprint on the density and velocity structure. Of the energy released by the inspiral of the cores, only about 25% goes toward ejection of the envelope.

  6. Comparisons Between SPH and Grid-Based Simulations of the Common Envelope Phase

    NASA Astrophysics Data System (ADS)

    Passy, Jean-Claude; Fryer, C. L.; Diehl, S.; De Marco, O.; Mac Low, M.; Herwig, F.; Oishi, J. S.

    2011-01-01

    The common envelope (CE) interaction between a giant star and a lower-mass companion provides a formation channel leading eventually to Type Ia supernovae, sdB stars and bipolar PNe. More broadly, it is an essential ingredient for any population synthesis study including binaries, e.g. cataclysmic variables. Occurring on a short time scale - typically between one and ten years, the CE interaction itself has so far never been observed with certainty but the existence of companions in close orbits around evolved stars, whose precursor's radius was larger than today's orbital separation, vouches for such interaction taking place frequently. Via a detailed study of the energetics and the use of stellar evolution models, we derived in our previous paper the efficiency α of the CE interaction from a carefully selected and statistically analyzed sample of systems thought to be outcomes of a CE interaction. We deduced the initial configuration of those systems using stellar models, and derived a possible inverse dependence of α with the companion to primary mass ratio. Here, we compare these predictions to numerical simulations with two different codes. Enzo is a 3D adaptive mesh refinement grid-based code. For our stellar problem we have modified the way gravity and boundary conditions are treated in this code. The SNSPH code is a 3D hydrodynamics SPH code using tree gravity. The results from both codes for different companion masses and different types of primary stars are consistent with each other. Those results include a resolution study of a 0.88 M⊙ red giant interacting with a 0.9, 0.6 and 0.3 M⊙ white dwarf, respectively. Those systems reach a final separation of 25, 18 and 10 R⊙, respectively. In this contribution, we present and discuss those results and compare them to our predictions. This research was funded by NSF grant 0607111.

  7. Merging in the common envelope and the origin of early R-type stars

    NASA Astrophysics Data System (ADS)

    Piersanti, L.; Cabezón, R. M.; Zamora, O.; Domínguez, I.; García-Senz, D.; Abia, C.; Straniero, O.

    2010-11-01

    Context. Binary systems experiencing one or two common envelope episodes during the red giant branch or the Hertzsprung gap phases can produce a single star, evolving along the Hayashi track, as a final outcome. Even if these objects are expected to be very common in nature, a proper description of their evolution and physical properties is still missing. Moreover, this scenario (red giant merging scenario) has been invoked as the progenitor systems of early-R stars, by assuming that the physical conditions developed as a consequence of the cores merging could produce the mixing into the convective envelope of fresh carbon that was synthesized during the He-flash. Aims: We analyze in detail the red giant merging scenario to verify if the resulting star develops the physical conditions suitable for a dredge-up of C-enriched material from the core to the envelope. Methods: We performed 3D simulations of the merging stars, to check whether He is burnt efficiently during the formation of a self-sustained disk. We therefore did 1D computations of the accretion phase occurring after the merging and of the following evolution up to the settling of quiescent He-burning in the center. We adopted different assumptions on the amount of angular momentum transferred from the disk to the core and on the angular momentum transport. Results: Efficient He-burning does not occur during the merging, because a very high temperature (T > 108 K) at the disk/He-core interface develops only for a few minutes. Our computations show that the accretion process is the leading parameter in determining the final properties of the merged object. In particular, the thermal energy delivered by the accreted matter determines the heating of the whole newborn core, thus preventing the developing of highly degenerate physical conditions. This occurrence determines the onset of the He-burning with an He-flash milder and closer to the center, as compared to standard RGB stars. Rotation and different

  8. Common envelope mechanisms: constraints from the X-ray luminosity function of high-mass X-ray binaries

    SciTech Connect

    Zuo, Zhao-Yu; Li, Xiang-Dong E-mail: lixd@nju.edu.cn

    2014-12-10

    We use the measured X-ray luminosity function (XLF) of high-mass X-ray binaries (HMXBs) in nearby star-forming galaxies to constrain the common envelope (CE) mechanisms, which play a key role in governing the binary evolution. We find that the XLF can be reproduced quite closely under both CE mechanisms usually adopted, i.e., the α{sub CE} formalism and the γ algorithm, with a reasonable range of parameters considered. Provided that the parameter combination is the same, the γ algorithm is likely to produce more HMXBs than the α{sub CE} formalism, by a factor of up to ∼10. In the framework of the α{sub CE} formalism, a high value of α{sub CE} is required to fit the observed XLF, though it does not significantly affect the global number of the HMXB populations. We present the detailed components of the HMXB populations under the γ algorithm and compare them with those in Zuo et al. and observations. We suggest the distinct observational properties, as well as period distributions of HMXBs, may provide further clues to discriminate between these two types of CE mechanisms.

  9. SIMULATING THE COMMON ENVELOPE PHASE OF A RED GIANT USING SMOOTHED-PARTICLE HYDRODYNAMICS AND UNIFORM-GRID CODES

    SciTech Connect

    Passy, Jean-Claude; Mac Low, Mordecai-Mark; De Marco, Orsola; Fryer, Chris L.; Diehl, Steven; Rockefeller, Gabriel; Herwig, Falk; Oishi, Jeffrey S.; Bryan, Greg L.

    2012-01-01

    We use three-dimensional hydrodynamical simulations to study the rapid infall phase of the common envelope (CE) interaction of a red giant branch star of mass equal to 0.88 M{sub Sun} and a companion star of mass ranging from 0.9 down to 0.1 M{sub Sun }. We first compare the results obtained using two different numerical techniques with different resolutions, and find very good agreement overall. We then compare the outcomes of those simulations with observed systems thought to have gone through a CE. The simulations fail to reproduce those systems in the sense that most of the envelope of the donor remains bound at the end of the simulations and the final orbital separations between the donor's remnant and the companion, ranging from 26.8 down to 5.9 R{sub Sun }, are larger than the ones observed. We suggest that this discrepancy vouches for recombination playing an essential role in the ejection of the envelope and/or significant shrinkage of the orbit happening in the subsequent phase.

  10. Binaries discovered by the SPY survey. VI. Discovery of a low mass companion to the hot subluminous planetary nebula central star EGB 5 - a recently ejected common envelope?

    NASA Astrophysics Data System (ADS)

    Geier, S.; Napiwotzki, R.; Heber, U.; Nelemans, G.

    2011-04-01

    Hot subdwarf B stars (sdBs) in close binary systems are assumed to be formed via common envelope ejection. According to theoretical models, the amount of energy and angular momentum deposited in the common envelope scales with the mass of the companion. That low mass companions near or below the core hydrogen-burning limit are able to trigger the ejection of this envelope is well known. The currently known systems have very short periods ≃0.1-0.3 d. Here we report the discovery of a low mass companion (M2 > 0.14 M⊙) orbiting the sdB star and central star of a planetary nebula EGB 5 with an orbital period of 16.5 d at a minimum separation of 23 R⊙. Its long period is only just consistent with the energy balance prescription of the common envelope. The marked difference between the short and long period systems will provide strong constraints on the common envelope phase, in particular if the masses of the sdB stars can be measured accurately. Due to selection effects, the fraction of sdBs with low mass companions and similar or longer periods may be quite high. Low mass stellar and substellar companions may therefore play a significant role for the still unclear formation of hot subdwarf stars. Furthermore, the nebula around EGB 5 may be the remnant of the ejected common envelope making this binary a unique system to study this short und poorly understood phase of binary evolution. Based on observations at the Paranal Observatory of the European Southern Observatory for programmes No. 167.H-0407(A) and 71.D-0383(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). Some of the data used in this work were obtained at the William Herschel Telescope (WHT) operated by the Isaac Newton Group of Telescopes (ING).

  11. Post-collision-interaction distortion of low-energy photoelectron spectra associated with double Auger decay

    SciTech Connect

    Gerchikov, L.; Sheinerman, S.

    2011-08-15

    Atomic inner-shell photoionization followed by double Auger decay is investigated. The focus of our study is the effect of post-collision interaction (PCI) on the photoelectron energy distribution. A semi-classical approach is employed to describe the PCI distortion of the photoelectron line shapes associated with both direct and cascade double Auger decays. This approach is shown to be valid at low photoelectron energies, whereas for large incident photon energies it reduces to the eikonal approximation. The theory is applied to the case of Ar 2p photoionization spectra and good agreement with available experimental data is achieved.

  12. On the inclusion of post-MP2 contributions to double-hybrid density functionals.

    PubMed

    Chan, Bun; Goerigk, Lars; Radom, Leo

    2016-01-15

    In this study, we explore the effect of supplementing the DuT spin-component-scaled double-hybrid density functional method with post-second-order Møller-Plesset-type theory (MP2) correlation terms. We find that the inclusion of additional MP3 correlation energies has almost no effect on the performance. Further addition of correlation effects from MP4 generally leads to a small improvement in the performance. However, we find that the inclusion of the higher-order perturbative correlation effects does not rectify some major shortcomings of DuT for more challenging systems, and the use of MP4, in fact, leads to a significant deterioration in the performance in some cases. We also find that the use of correlation energies from CCSD(T) instead of those from MP3 and MP4 does not lead to a substantial improvement over the MP4-based method, both in general and in some difficult cases that we have examined. An additional observation is that, for large systems that are dominated by noncovalent interactions, DuT and the two MPn-based post-MP2 double-hybrid density functional theory (DFT) procedures all benefit from the inclusion of dispersion corrections. Overall, our investigation suggests that the current generation of MP2-based double-hybrid DFT methods may already be providing close to the optimal performance that can be achieved with the double-hybrid methodology paired with spin-component-scaling. Development of even better double hybrids is an active research field, and we hope that our study provides valuable insights. We recommend the continuing use of existing MP2-based double-hybrid methods as a bridging level between hybrid density functional procedures and high-level wave-function-based procedures. PMID:26135403

  13. Double-concave deformity of the polyethylene tibial post in posterior stabilized total knee arthroplasty.

    PubMed

    Niki, Yasuo; Matsumoto, Hideo; Yoshimine, Fumihiro; Toyama, Yoshiaki; Suda, Yasunori; Banks, Scott A

    2010-04-01

    This report describes a unique case of bilateral total knee arthroplasty necessitating revision of the polyethylene insert, which showed prominent marks on the tibial post resulting from repeated seiza-style sitting. The patient presented 7 years postoperatively with knee pain and flexion disturbance due to continuous joint effusion persisting for more than 4 months. Proliferating synovia throughout the joint revealed reactive synovitis to polyethylene particles. The retrieved polyethylene inserts displayed double-concave deformity of the tibial post with burnishing and creep in tibiofemoral articulation. The damage pattern of retrieved polyethylene inserts reflected the data from tibiofemoral contact location obtained using a shape-matching technique in the early postoperative phase. This case provides an example of damage to the polyethylene tibial post caused by a floor-sitting lifestyle and the potential clinical sequelae. PMID:19261434

  14. Recombination energy in double white dwarf formation

    NASA Astrophysics Data System (ADS)

    Nandez, J. L. A.; Ivanova, N.; Lombardi, J. C.

    2015-06-01

    In this Letter, we investigate the role of recombination energy during a common envelope event. We confirm that taking this energy into account helps to avoid the formation of the circumbinary envelope commonly found in previous studies. For the first time, we can model a complete common envelope event, with a clean compact double white dwarf binary system formed at the end. The resulting binary orbit is almost perfectly circular. In addition to considering recombination energy, we also show that between 1/4 and 1/2 of the released orbital energy is taken away by the ejected material. We apply this new method to the case of the double white dwarf system WD 1101+364, and we find that the progenitor system at the start of the common envelope event consisted of an ˜1.5 M⊙ red giant star in an ˜30 d orbit with a white dwarf companion.

  15. A large, long-lived structure near the trojan L5 point in the post common-envelope binary SDSS J1021+1744

    NASA Astrophysics Data System (ADS)

    Irawati, P.; Richichi, A.; Bours, M. C. P.; Marsh, T. R.; Sanguansak, N.; Chanthorn, K.; Hermes, J. J.; Hardy, L. K.; Parsons, S. G.; Dhillon, V. S.; Littlefair, S. P.

    2016-03-01

    SDSS J1021+1744 is a detached, eclipsing white dwarf/M dwarf binary discovered in the Sloan Digital Sky Survey (SDSS). Outside the primary eclipse, the light curves of such systems are usually smooth and characterized by low-level variations caused by tidal distortion and heating of the M star component. Early data on SDSS J1021+1744 obtained in 2012 June were unusual in showing a dip in flux of uncertain origin shortly after the white dwarf's eclipse. Here we present high-time resolution, multiwavelength observations of 35 more eclipses over 1.3 yr, showing that the dip has a lifetime extending over many orbits. Moreover the `dip' is in fact a series of dips that vary in depth, number and position, although they are always placed in the phase interval 1.06-1.26 after the white dwarf's eclipse, near the L5 point in this system. Since SDSS J1021+1744 is a detached binary, it follows that the dips are caused by the transit of the white dwarf by material around the Lagrangian L5 point. A possible interpretation is that they are the signatures of prominences, a phenomenon already known from H α observations of rapidly rotating single stars as well as binaries. What makes SDSS J1021+1744 peculiar is that the material is dense enough to block continuum light. The dips appear to have finally faded out around 2015 May after the first detection by Parsons et al. in 2012, suggesting a lifetime of years.

  16. Post heat treatment effects on double layer metal structures for VLSI applications

    NASA Technical Reports Server (NTRS)

    Wade, T. E.; Trotter, J. D.

    1978-01-01

    The realization of high yield double layer metal systems using wet chemistry processes and the ability to extend yields beyond that attainable with wet chemistry by means of post sintering processes at temperatures below 500 C for potential applications in very large scale integration structures were studied. Yields in excess of 98% and average total contact resistance of less than 150 ohms and 200 ohms were realized for a series of 560 vias of 0.5 X 0.5 mils and 0.2 X 0.2 mils in size, respectively.

  17. Randomised double-blind comparative study of dexmedetomidine and tramadol for post-spinal anaesthesia shivering

    PubMed Central

    Mittal, Geeta; Gupta, Kanchan; Katyal, Sunil; Kaushal, Sandeep

    2014-01-01

    Background and Aims: Dexmedetomidine (α2 adrenergic agonist) has been used for prevention of post anaesthesia shivering. Its use for the treatment of post-spinal anaesthesia shivering has not been evaluated. The aim of this study was to evaluate and compare the efficacy, haemodynamic and adverse effects of dexmedetomidine with those of tramadol, when used for control of post-spinal anaesthesia shivering. Methods: A prospective, randomised, and double-blind study was conducted in 50 American Society of Anaesthesiologists Grade I and II patients of either gender, aged between 18 and 65 years, scheduled for various surgical procedures under spinal anaesthesia. The patients were randomised in two groups of 25 patients each to receive either dexmedetomidine 0.5 μg/kg or tramadol 0.5 mg/kg as a slow intravenous bolus. Grade of shivering, onset of shivering, time for cessation of shivering, recurrence, response rate, and adverse effects were observed at scheduled intervals. Unpaired t-test was used for analysing the data. Results: Time taken for cessation of shivering was significantly less with dexmedetomidine when compared to tramadol. Nausea and vomiting was observed only in tramadol group (28% and; 20% respectively). There was not much difference in the sedation profile of both the drugs. Conclusion: We conclude that although both drugs are effective, the time taken for cessation of shivering is less with dexmedetomidine when compared to tramadol. Moreover, dexmedetomidine has negligible adverse effects, whereas tramadol is associated with significant nausea and vomiting. PMID:25024466

  18. Syrup formulations for post-tonsillectomy analgesia: a double-blind study comparing ibuprofen, aspirin and placebo.

    PubMed

    Parker, D A; Gibbin, K P; Noyelle, R M

    1986-09-01

    Post-tonsillectomy analgesia from ibuprofen, aspirin and placebo is compared in a double-blind study. The results are reported showing ibuprofen to have greater therapeutic benefit than placebo whereas aspirin did not. Methods of providing pain relief after tonsillectomy and the relative clinical merits of ibuprofen and aspirin are discussed. PMID:3531373

  19. Post-treatment of anaerobic reactor effluent using coagulation/oxidation followed by double filtration.

    PubMed

    Cavallini, Grasiele Soares; de Sousa Vidal, Carlos Magno; de Souza, Jeanette Beber; de Campos, Sandro Xavier

    2016-04-01

    This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90% and close to 100% removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65% recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing. PMID:26611629

  20. Applying the Post-Modern Double ABC-X Model to Family Food Insecurity

    ERIC Educational Resources Information Center

    Hutson, Samantha; Anderson, Melinda; Swafford, Melinda

    2015-01-01

    This paper develops the argument that using the Double ABC-X model in family and consumer sciences (FCS) curricula is a way to educate nutrition and dietetics students regarding a family's perceptions of food insecurity. The Double ABC-X model incorporates ecological theory as a basis to explain family stress and the resulting adjustment and…

  1. "Hits" (Not "Discussion Posts") Predict Student Success in Online Courses: A Double Cross-Validation Study

    ERIC Educational Resources Information Center

    Ramos, Cheryl; Yudko, Errol

    2008-01-01

    The efficacy of individual components of an online course on positive course outcome was examined via stepwise multiple regression analysis. Outcome was measured as the student's total score on all exams given during the course. The predictors were page hits, discussion posts, and discussion reads. The vast majority of the variance of outcome was…

  2. Introduction of double amidoxime group by double post surface modification on poly(vinylbenzyl chloride) beads for higher amounts of organic dyes, As (V) and Cr (VI) removal.

    PubMed

    Ajmal, Muhammad; Demirci, Sahin; Uzun, Yusuf; Siddiq, Mohammad; Aktas, Nahit; Sahiner, Nurettin

    2016-05-15

    In this study, the synthesis of micron-sized poly(vinylbenzyl chloride) (p(VBC)) beads and subsequent conversion of the reactive chloromethyl groups to double amidoxime group containing moieties by post modification is reported. The prepared beads were characterized by SEM and FT-IR spectroscopy. The amidoximated p(VBC) beads were used as adsorbent for the removal of organic dyes, such as eosin y (EY) and methyl orange (MO), and heavy metals containing complex ions such as dichromate (Cr2O7(2-)) and arsenate (HAsO4(2)(-)) from aqueous media. The effect of the adsorbent dose on the percent removal, the effect of initial concentration of adsorbates on the adsorption rate and their amounts were also investigated. The Langmuir, Freundlich and Temkin adsorption isotherms were applied to the adsorption processes. The results indicated that the adsorption of both dichromate and arsenate ions obeyed the Langmuir adsorption model. Interestingly, it was found that the prepared beads were capable of removing significant amounts of arsenate and dichromate ions from tap and river (Sarıcay, Canakkale-Turkey) water. PMID:26930538

  3. High speed EUV using post processing and self-aligned double patterning as a speed enhancement technique

    NASA Astrophysics Data System (ADS)

    Wandell, Jerome; deVilliers, Anton; Huli, Lior; Biesemans, Serge; Nafus, Kathleen; Carcasi, Mike; Smith, Jeff; Hetzer, Dave; Higgins, Craig; Rastogi, Vinayak; Verduijn, Erik

    2014-04-01

    EUV is an ongoing industry challenge to adopt due to its current throughput limitations. The approach to improve throughput has primarily been through a significant focus on source power which has been a continuing challenge for the industry. The subject of this paper is to review and investigate the application of SADP (Self aligned double patterning) as a speed enhancing technique for EUV processing. A process with the potential of running a 16 nm self-aligned final etched pattern in less than 10mJ exposure range is proposed. Many of the current challenges with shot noise and resolution change significantly when SADP is used in conjunction with EUV. In particular, the resolution challenge for a 16nm HP final pattern type image changes to 32nm as an initial pattern requirement for the patterned CD. With this larger CD starting point, the burden of shot noise changes significantly and the ability for higher speed resist formulations to be used is enabled. Further resist candidates that may have not met the resolution requirements for EUV can also be evaluated. This implies a completely different operational set-point for EUV resist chemistry where the relaxation of both LER and CD together combined, give the resist formulation space a new target when EUV is used as a SADP tool. Post processing mitigation of LWR is needed to attain the performance of the final 16nm half pitch target pattern to align with the industry needs. If the original process flow at an 85W projected source power would run in the 50WPH range, then the flow proposed here would run in the <120WPH range. Although it is a double patterning technology, the proposed process still only requires a single pass through the EUV tool, This speed benefit can be used to offset the added costs associated with the double patterning process. This flow can then be shown to be an enabling approach for many EUV applications.

  4. Double White Dwarfs as Probes of Single and Binary Star Evolution

    NASA Astrophysics Data System (ADS)

    Andrews, Jeffrey John

    2016-01-01

    As the endpoints of stars less massive than roughly eight solar masses, the population of Galactic white dwarfs (WD) contain information about complex stellar evolution processes. Associated pairs of WDs add an extra degree of leverage; both WDs must have formed and evolved together. The work presented in this dissertation uses various populations of double WDs (DWD) to constrain evolution of both single and binary stars. One example is the set of low-mass WDs with unseen WD companions, which are formed through a dynamically-unstable mass loss process called the common envelope. To work toward a quantitative understanding of the common envelope, we develop and apply a Bayesian statistical technique to identify the masses of the unseen WD companions. We provide results which can be compared to evolutionary models and hence a deeper understanding of how binary stars evolve through a common envelope. The statistical technique we develop can be applied to any population of single-line spectroscopic binaries. Binaries widely separated enough that they avoid any significant interaction independently evolve into separate WDs that can be identified in photometric and astrometric surveys. We discuss techniques for finding these objects, known as wide DWDs. We present a catalog of 142 candidate wide DWDs, combining both previously detected systems and systems we identify in our searches in the Sloan Digital Sky Survey. Having been born at the same time, the masses and cooling ages of the WDs in wide DWDs, obtained with our spectroscopic follow-up campaign can be used to constrain the initial-final mass relation, which relates a main sequence star to the mass of the WD into which it will evolve. We develop a novel Bayesian technique to interpret our data and present our resulting constraints on this relation which are particularly strong for initial masses between two and four solar masses. During this process, we identified one wide DWD, HS 2220+2146, that was peculiar since

  5. Post unilateral lesion response biases modulate memory: crossed double dissociation of hemispheric specialisations.

    PubMed

    Braun, Claude M J; Delisle, Josée; Guimond, Anik; Daigneault, Rafaël

    2009-03-01

    We propose that what appears to be hemispheric specialisation in the memory domain, as indexed by effects of unilateral brain lesions, is to a great extent explainable as response bias: left hemisphere lesions result in an omissive response bias or error pattern whereas right hemisphere lesions result in a commissive response bias or error pattern. To test this prediction a group of 40 non-confabulatory cases with a verbal and non-verbal retention deficit (hypomnesia), subsequent to a unilateral lesion, was assembled from the literature. A group of non-amnesic cases with confabulation, paramnesia, false memories or memory-laden hallucination (dysfunctional hypermnesia), due to a unilateral lesion, was also assembled from the literature (N=72). Most of the hypomnesic patients had left hemisphere lesions (73%, p<.005, two tailed) while most of the hypermnesic patients had right hemisphere lesions (78%, p<.0005, two tailed). This crossed double dissociation held good despite statistical control of the lesion's locus within the hemisphere, its size or its aetiology, presence of aphasic symptoms, psychiatric comorbidity, the patient's age, gender, or hand preference, and several other potentially confounding variables. PMID:18991140

  6. Controlled DNA double-strand break induction in mice reveals post-damage transcriptome stability.

    PubMed

    Kim, Jeongkyu; Sturgill, David; Tran, Andy D; Sinclair, David A; Oberdoerffer, Philipp

    2016-04-20

    DNA double-strand breaks (DSBs) and their repair can cause extensive epigenetic changes. As a result, DSBs have been proposed to promote transcriptional and, ultimately, physiological dysfunction via both cell-intrinsic and cell-non-autonomous pathways. Studying the consequences of DSBs in higher organisms has, however, been hindered by a scarcity of tools for controlled DSB induction. Here, we describe a mouse model that allows for both tissue-specific and temporally controlled DSB formation at ∼140 defined genomic loci. Using this model, we show that DSBs promote a DNA damage signaling-dependent decrease in gene expression in primary cells specifically at break-bearing genes, which is reversed upon DSB repair. Importantly, we demonstrate that restoration of gene expression can occur independently of cell cycle progression, underlining its relevance for normal tissue maintenance. Consistent with this, we observe no evidence for persistent transcriptional repression in response to a multi-day course of continuous DSB formation and repair in mouse lymphocytesin vivo Together, our findings reveal an unexpected capacity of primary cells to maintain transcriptome integrity in response to DSBs, pointing to a limited role for DNA damage as a mediator of cell-autonomous epigenetic dysfunction. PMID:26687720

  7. Controlled DNA double-strand break induction in mice reveals post-damage transcriptome stability

    PubMed Central

    Kim, Jeongkyu; Sturgill, David; Tran, Andy D.; Sinclair, David A.; Oberdoerffer, Philipp

    2016-01-01

    DNA double-strand breaks (DSBs) and their repair can cause extensive epigenetic changes. As a result, DSBs have been proposed to promote transcriptional and, ultimately, physiological dysfunction via both cell-intrinsic and cell-non-autonomous pathways. Studying the consequences of DSBs in higher organisms has, however, been hindered by a scarcity of tools for controlled DSB induction. Here, we describe a mouse model that allows for both tissue-specific and temporally controlled DSB formation at ∼140 defined genomic loci. Using this model, we show that DSBs promote a DNA damage signaling-dependent decrease in gene expression in primary cells specifically at break-bearing genes, which is reversed upon DSB repair. Importantly, we demonstrate that restoration of gene expression can occur independently of cell cycle progression, underlining its relevance for normal tissue maintenance. Consistent with this, we observe no evidence for persistent transcriptional repression in response to a multi-day course of continuous DSB formation and repair in mouse lymphocytes in vivo. Together, our findings reveal an unexpected capacity of primary cells to maintain transcriptome integrity in response to DSBs, pointing to a limited role for DNA damage as a mediator of cell-autonomous epigenetic dysfunction. PMID:26687720

  8. Fully 3D Particle-in-Cell Simulation of Double Post-Hole Convolute on PTS Facility

    NASA Astrophysics Data System (ADS)

    Zhao, Hailong; Dong, Ye; Zhou, Haijing; Zou, Wenkang; Institute of Fluid Physics Collaboration; Institute of Applied Physics; Computational Mathematics Collaboration

    2015-11-01

    In order to get better understand of energy transforming and converging process during High Energy Density Physics (HEDP) experiments, fully 3D particle-in-cell (PIC) simulation code NEPTUNE3D was used to provide numerical approach towards parameters which could hardly be acquired through diagnostics. Cubic region (34cm × 34cm × 18cm) including the double post-hole convolute (DPHC) on the primary test stand (PTS) facility was chosen to perform a series of fully 3D PIC simulations, calculating ability of codes were tested and preliminary simulation results about DPHC on PTS facility were discussed. Taking advantages of 3D simulation codes and large-scale parallel computation, massive data (~ 250GB) could be acquired in less than 5 hours and clear process of current transforming and electron emission in DPHC were demonstrated with the help of visualization tools. Cold-chamber tests were performed during which only cathode electron emission was considered without temperature rise or ion emission, current loss efficiency was estimated to be 0.46% ~ 0.48% by comparisons between output magnetic field profiles with or without electron emission. Project supported by the National Natural Science Foundation of China (Grant No. 11205145, 11305015, 11475155).

  9. A novel mechanism for creating double pulsars

    NASA Technical Reports Server (NTRS)

    Sigurdsson, Steinn; Hernquist, Lars

    1992-01-01

    Simulations of encounters between pairs of hard binaries, each containing a neutron star and a main-sequence star, reveal a new formation mechanism for double pulsars in dense cores of globular clusters. In many cases, the two normal stars are disrupted to form a common envelope around the pair of neutron stars, both of which will be spun up to become millisecond pulsars. We predict that a new class of pulsars, double millisecond pulsars, will be discovered in the cores of dense globular clusters. The genesis proceeds through a short-lived double-core common envelope phase, with the envelope ejected in a fast wind. It is possible that the progenitor may also undergo a double X-ray binary phase. Any circular, short-period double pulsar found in the galaxy would necessarily come from disrupted disk clusters, unlike Hulse-Taylor class pulsars or low-mass X-ray binaries which may be ejected from clusters or formed in the galaxy.

  10. The Effect of Prophylactic Antibiotics on Post Laparoscopic Cholecystectomy Infectious Complications: A Double-Blinded Clinical Trial

    PubMed Central

    Darzi, Ali Asghar; Nikmanesh, Alieh; Bagherian, Farhad

    2016-01-01

    Background Laparoscopic cholecystectomy (LC) is one of the most common surgeries in laparoscopic surgery. Although, it is believed that LC has low-risk for post-operative infectious complications, the use of a prophylactic antibiotic is still controversial in elective LC. Objective To determine the impact of prophylactic antibiotics on postoperative infection complications in elective laparoscopic cholecystectomy. Methods In this double-blind, placebo-controlled, randomized, clinical trial, patients who were candidates for elective LC, from March 2012 to 2015, in four hospitals in Babol, Iran, were studied. Patients were allocated randomly to two groups, i.e., group C: Cefazolin (n = 182) and group P: placebo (n = 247). Group C received 1 g of Cefazolin 30 minutes before anesthesia and and then, six and 12 hours after anesthesia. Group P patients received 10 ml of isotonic sodium chloride solution. Age, gender, type of gallbladder diseases (stone, polyp, or hydrops), the length of post-operative hospitalization, frequency of gallbladder rupture, the duration of surgery, and the kinds of complications associated with infections were collected for each patient in the two groups. The data were analyzed by IBM-SPSS version 20, using the t-test and the chi-squared test, and a p-value < 0.05 was considered as significant. Results There were no significant differences between the two groups in terms of gender (C versus P: 18 (9.9%) male versus 22 (9%); p = 0.74), age (C versus P: 43.75 + 13.30 years versus 40.91 + 13.05; p = 0.20), and duration of surgery (C versus P: 34.97 ± 8.25 min versus 34.11 ± 8.39; p = 0.71). There were no significant differences between the two groups in the incidences of post-operative infection (C versus P: 3 (1.7%) versus 5 (2%); p = 0.99) and rupture of the gallbladder (C versus P: 14 (7.8%) versus 17 (6.8%); p = 0.85). No other post-operative systemic infectious complications (e.g., sepsis, pneumonia, or urinary tract infection) were found

  11. A double detached shell around a post-red supergiant: IRAS 17163-3907, the Fried Egg nebula

    NASA Astrophysics Data System (ADS)

    Lagadec, E.; Zijlstra, A. A.; Oudmaijer, R. D.; Verhoelst, T.; Cox, N. L. J.; Szczerba, R.; Mékarnia, D.; van Winckel, H.

    2011-10-01

    Context. We performed a mid-infrared imaging survey of evolved stars to study the dust distribution in circumstellar envelopes around these objects and to understand the mass-loss mechanism responsible for the formation of these envelopes better. During this survey, we resolved the circumstellar environment of IRAS 17163-3907 for the first time (hereafter IRAS 17163), which is one of the brightest objects in the mid-infrared sky, but is surprisingly not well studied. Aims: Our aim is to determine the evolutionary status of IRAS 17163 and study its circumstellar environment to understand its mass-loss history. Methods: We obtained diffraction-limited images of IRAS 17163 in the mid-infrared using VISIR on the VLT. Optical spectra of the object allowed us to determine its spectral type and estimate its distance through diffuse interstellar bands. Results: We show that IRAS 17163 is a post-red supergiant, possibly belonging to the rare class of yellow hypergiants, and is very similar to the well-studied object IRC +10420. Our mid-infrared images of IRAS 17163 are the first direct images of this bright mid-infrared source. These images clearly show a double dusty detached shell around the central star, caused by successive ejections of material on a timescale of the order of 400 years and a total circumstellar mass exceeding than 4 M⊙. This indicates that non-quiescent mass-loss occurs during this phase of stellar evolution. Based on observations made with the Very Large Telescope at Paranal Observatory under program 081.D-0130(A).Based on observations made with the Mercator Telescope, operated on the island of La Palma by the Flemish Community, at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofsica de Canarias.

  12. Double-core evolution. 5: Three-dimensional effects in the merger of a red giant with a dwarf companion

    NASA Technical Reports Server (NTRS)

    Terman, James L.; Taam, Ronald E.; Hernquist, Lars

    1994-01-01

    The evolution of the common envelope phase of a binary system consisting of a 4.67 solar mass red giant and a 0.94 solar mass dwarf is studied using smoothed particle hydrodynamics. We demonstrate that the three-dimensional effects associated with the gravitational tidal torques lead to a rapid decay of the orbit on timescales approximately less than 1 yr. The relative orbit of the two cores in the common envelope is initally eccentric and tends to circularize as the orbital separation of the two cores decreases. The angular momentum lost from the orbital motion is distributed throughout the common envelope, and the double core does not evolve to a state of co-rotation for the evolutionary time followed. The energy dissipated from the relative orbit and deposited in the common envelope results in the ejection of approximately 13% of the mass of the envelope. The mass is ejected in all directions, but there is a preference for mass ejection in the orbital plane of the binary system. For example, approximately 80% of the ejected mass lies within 30 deg of the binary orbital plane. Because gravitational forces are long range, most of the energy and angular momentum is imparted to a small fraction of the common envelope resulting in an efficiency of the mass ejection process of approximately 15%. The core of the red giant executes significant displacement with respect to the center of mass of the system and contributes nearly equally to the total energy dissipation rate during the latter phases of the evolution. The degree of departure from synchronism of the initial binary system can be an important property of the system which can affect the outcome of the common envelope phase.

  13. REPRODUCING THE OBSERVED ABUNDANCES IN RCB AND HdC STARS WITH POST-DOUBLE-DEGENERATE MERGER MODELS-CONSTRAINTS ON MERGER AND POST-MERGER SIMULATIONS AND PHYSICS PROCESSES

    SciTech Connect

    Menon, Athira; Herwig, Falk; Denissenkov, Pavel A.; Clayton, Geoffrey C.; Staff, Jan; Pignatari, Marco; Paxton, Bill

    2013-07-20

    The R Coronae Borealis (RCB) stars are hydrogen-deficient, variable stars that are most likely the result of He-CO WD mergers. They display extremely low oxygen isotopic ratios, {sup 16}O/{sup 18}O {approx_equal} 1-10, {sup 12}C/{sup 13}C {>=} 100, and enhancements up to 2.6 dex in F and in s-process elements from Zn to La, compared to solar. These abundances provide stringent constraints on the physical processes during and after the double-degenerate merger. As shown previously, O-isotopic ratios observed in RCB stars cannot result from the dynamic double-degenerate merger phase, and we now investigate the role of the long-term one-dimensional spherical post-merger evolution and nucleosynthesis based on realistic hydrodynamic merger progenitor models. We adopt a model for extra envelope mixing to represent processes driven by rotation originating in the dynamical merger. Comprehensive nucleosynthesis post-processing simulations for these stellar evolution models reproduce, for the first time, the full range of the observed abundances for almost all the elements measured in RCB stars: {sup 16}O/{sup 18}O ratios between 9 and 15, C-isotopic ratios above 100, and {approx}1.4-2.35 dex F enhancements, along with enrichments in s-process elements. The nucleosynthesis processes in our models constrain the length and temperature in the dynamic merger shell-of-fire feature as well as the envelope mixing in the post-merger phase. s-process elements originate either in the shell-of-fire merger feature or during the post-merger evolution, but the contribution from the asymptotic giant branch progenitors is negligible. The post-merger envelope mixing must eventually cease {approx}10{sup 6} yr after the dynamic merger phase before the star enters the RCB phase.

  14. Double-blind controlled trial to compare anti-inflammatory effects of tolmetin 2%, prednisolone 0.5%, and placebo in post-cataract extraction eyes.

    PubMed Central

    Smerdon, D L; Hung, S O; Akingbehin, T

    1986-01-01

    This paper compares the efficacy of tolmetin, prednisolone, and placebo (vehicle only) in controlling post-cataract extraction inflammation in a double-blind trial involving 120 patients. Seventeen patients were excluded from analysis. The results of the 103 patients analysed showed that 94% of the prednisolone treated group was judged to have been successfully treated as compared with 53% of the tolmetin treated group and 46% of the vehicle treated group. The differences between the prednisolone treated group and the other two groups were statistically significant (p less than 0.001). No statistical significance was found between the tolmetin and vehicle groups. PMID:3535872

  15. Granisetron versus ondansetron for post-operative nausea and vomiting prophylaxis in elective craniotomies for brain tumors: A randomized controlled double-blind study

    PubMed Central

    Gupta, Priyanka; Sabharwal, Nikki; Kale, Suniti; Gupta, Mayank; Gogia, Anoop R.

    2014-01-01

    Context: Post-operative nausea and vomiting (PONV) pose unique challenges in neurosurgical patients that warrant its study separate from other surgical groups. Setting and Design: This prospective, randomized, double-blind study was carried out to compare and to evaluate the efficacy and safety of three antiemetic combinations for PONV prophylaxis following craniotomy. Materials and Methods: A total of 75 anesthesiologist status I/II patients undergoing elective craniotomy for brain tumors were randomized into three groups, G, O and D, to receive single doses of dexamethasone 8 mg at induction with either granisetron 1 mg, ondansetron 4 mg or normal saline 2 ml at the time of dural closure respectively. Episodes of nausea, retching, vomiting and number of rescue antiemetic (RAE) were noted for 48 h post-operatively. Statistical Analysis: Analysis of variance with post-hoc significance and Chi-square test with fisher exact correction were used for statistical analysis. P <0.05 was considered to be significant and P < 0.001 as highly significant. Results: We found that the incidence and number of vomiting episodes and RAE required were significantly low in Group G and O compared with Group D; P < 0.05. However, incidence of nausea and retching were comparable among all groups. The anti-nausea and anti-retching efficacy of all the three groups was comparable. Conclusions: Single dose administration of granisetron 1 mg or ondansetron 4 mg at the time of dural closure with dexamethasone 8 mg provide an effective and superior prophylaxis against vomiting compared with dexamethasone alone without interfering with post-operative recovery and neurocognitive monitoring and hence important in post-operative neurosurgical care. PMID:25886108

  16. An ALMA View of the Complex Circumstellar Environment of the Post-AGB Object HD 101584

    NASA Astrophysics Data System (ADS)

    Olofsson, H.; Vlemmings, W.; Maercker, M.; Humphreys, E.; Lindqvist, M.; Nyman, L.; Ramstedt, S.

    2015-12-01

    We use 12CO, 13CO, and C18O J = 2-1 lines and 1.3 mm continuum ALMA observations to study the circumstellar evolution of the binary HD 101584, a post-AGB star and a low-mass companion, which is most likely a post-common-envelope-evolution system. It is inferred that the circumstellar medium has a bipolar hour-glass structure, seen almost pole-on, formed by an energetic, ≍ 150 km s-1, jet. Significant amount of material resides in an unresolved central region. It is proposed that the circumstellar morphology is related to an event which took place ≍ 500 yr ago, possibly a capture event where the companion spiraled in towards the AGB star. However, the kinetic energy of the accelerated gas exceeds the released orbital energy. Hence, the observed phenomenon does not match current common-envelope scenarios, and another process must augment, or even dominate, the ejection process.

  17. Post-irradiation chemical processing of DNA damage generates double-strand breaks in cells already engaged in repair

    PubMed Central

    Singh, Satyendra K.; Wang, Minli; Staudt, Christian; Iliakis, George

    2011-01-01

    In cells exposed to ionizing radiation (IR), double-strand breaks (DSBs) form within clustered-damage sites from lesions disrupting the DNA sugar–phosphate backbone. It is commonly assumed that these DSBs form promptly and are immediately detected and processed by the cellular DNA damage response (DDR) apparatus. This assumption is questioned by the observation that after irradiation of naked DNA, a fraction of DSBs forms minutes to hours after exposure as a result of temperature dependent, chemical processing of labile sugar lesions. Excess DSBs also form when IR-exposed cells are processed at 50°C, but have been hitherto considered method-related artifact. Thus, it remains unknown whether DSBs actually develop in cells after IR exposure from chemically labile damage. Here, we show that irradiation of ‘naked’ or chromatin-organized mammalian DNA produces lesions, which evolve to DSBs and add to those promptly induced, after 8–24 h in vitro incubation at 37°C or 50°C. The conversion is more efficient in chromatin-associated DNA, completed within 1 h in cells and delayed in a reducing environment. We conclude that IR generates sugar lesions within clustered-damage sites contributing to DSB formation only after chemical processing, which occurs efficiently at 37°C. This subset of delayed DSBs may challenge DDR, may affect the perceived repair kinetics and requires further characterization. PMID:21745815

  18. Japanese POEMS syndrome with Thalidomide (J-POST) Trial: study protocol for a phase II/III multicentre, randomised, double-blind, placebo-controlled trial

    PubMed Central

    Katayama, Kanako; Misawa, Sonoko; Sato, Yasunori; Sobue, Gen; Yabe, Ichiro; Watanabe, Osamu; Nishizawa, Masatoyo; Kusunoki, Susumu; Kikuchi, Seiji; Nakashima, Ichiro; Ikeda, Shu-ichi; Kohara, Nobuo; Kanda, Takashi; Kira, Jun-ichi; Hanaoka, Hideki; Kuwabara, Satoshi

    2015-01-01

    Introduction Polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS) syndrome is a fatal systemic disorder associated with plasma cell dyscrasia and the overproduction of the vascular endothelial growth factor (VEGF). Recently, the prognosis of POEMS was substantially improved by introduction of therapeutic intervention for myeloma. However, no randomised clinical trial has been performed because of the rarity and severity of the disease. Methods and analysis The Japanese POEMS syndrome with Thalidomide (J-POST) Trial is a phase II/III multicentre, double-blinded, randomised, controlled trial that aims to evaluate the efficacy and safety of a 24-week treatment with thalidomide in POEMS syndrome, with an additional 48-week open-label safety study. Adults with POEMS syndrome who have no indication for transplantation are assessed for eligibility at 12 tertiary neurology centres in Japan. Patients who satisfy the eligibility criteria are randomised (1:1) to receive thalidomide (100–300 mg daily) plus dexamethasone (12 mg/m2 on days 1–4 of a 28-day cycle) or placebo plus dexamethasone. Both treatments were administered for 24 weeks (six cycles; randomised comparative study period). Patients who complete the randomised study period or show subacute deterioration during the randomised period participate in the subsequent 48-week open-label safety study (long-term safety period). The primary end point of the study is the reduction rate of serum VEGF levels at 24 weeks. Ethics and dissemination The protocol was approved by the Institutional Review Board of each hospital. The trial was notified and registered at the Pharmaceutical and Medical Devices Agency, Japan (No. 22-1716). The J-POST Trial is currently ongoing and is due to finish in August 2015. The findings of this trial will be disseminated through peer-reviewed publications and conference presentations and will also be disseminated to participants. Trial registration number

  19. Comparison of Efficacy of Clonidine versus Ondansetron for Prevention of Nausea and Vomiting Post Thyroidectomy: A Double Blind Randomized Controlled Trial

    PubMed Central

    Shilpa, Setty Nagendra Gupta; Hilda, Selvaraj Shanthini

    2015-01-01

    Background and Aim Postoperative nausea vomiting (PONV) is the most common symptom in patients post thyroidectomy. Literature search shows conflicting results regarding use of clonidine in PONV prophylaxis. We undertook this randomized controlled double blind trial to compare the efficacy of clonidine with dexamethasone versus ondansetron with dexamethasone for PONV prophylaxis in these patients. Materials and Methods In this prospective study, 60 consecutive patients posted for thyroidectomy from August 2013 to July 2014, were randomly assigned to two groups, ondansetron (N= 30) (Group A) and clonidine (N= 30) (Group B). Patients received either oral ondansetron 8mg or oral clonidine 150μg as premedication. At the end of surgery, both groups received dexamethasone 8mg intravenously. They were monitored for occurrence of PONV and sore throat for next 24 h. Ramsay sedation scores and total time of analgesia was noted. The primary end point was incidence of PONV in post operative for 24 h. Pearson’s chi square test and Students t tests were performed using SPSS for windows version 20 (SPSS Inc., Chicago, IL). Results Baseline characteristics of patients were comparable. A higher proportion of patients in clonidine group developed PONV than ondansetron (36.7% vs 30%; p=0.03). Clonidine group patients experienced early nausea and vomiting (1-2hrs of postoperative period), compared to ondansetron group patients (6-12 h). Ramsay sedation scores at arrival were higher in clonidine group compared to ondansetron group (2.1 ± 0.3 versus 2.0; p=0.003). Total time of analgesia was higher with use of clonidine than ondansetron (919.5 ± 622 mins versus 642 ± 631 mins; p=0.09). Moderate sore throat was seen in 2 out of 30 patients in both groups. No major adverse events were observed in either group. Conclusion Ondansetron with dexamethasone group was more effective in controlling PONV after thyroidectomy compared to clonidine with dexamethasone group. However, ramsay

  20. Fluoroscopic Caudal Epidural Injections in Managing Post Lumbar Surgery Syndrome: Two-Year Results of a Randomized, Double-Blind, Active-Control Trial

    PubMed Central

    Manchikanti, Laxmaiah; Singh, Vijay; Cash, Kimberly A.; Pampati, Vidyasagar; Datta, Sukdeb

    2012-01-01

    Study Design: A randomized, active control, double-blind trial. Objective: To evaluate the effectiveness of fluoroscopically directed caudal epidural injections with or without steroids in managing chronic low back and lower extremity pain secondary to post lumbar surgery syndrome. Summary of Background Data: There is a paucity of evidence concerning caudal epidural injections for managing chronic persistent low back pain with or without lower extremity pain caused by post lumbar surgery syndrome. Methods: This active control randomized study included 140 patients with 70 patients in each group. Group I received 0.5% lidocaine, 10 mL; Group II received 9 mL of 0.5% lidocaine mixed with 1 mL of 6 mg of nonparticulate betamethasone. The multiple outcome measures included the numeric rating scale, the Oswestry Disability Index 2.0, employment status, and opioid intake with assessments at 3, 6, 12, 18, and 24 months posttreatment. Primary outcome was defined as at least 50% improvement in pain and Oswestry Disability Index scores. Patients with a positive response to the first 2 procedures with at least 3 weeks of relief were considered to be successful. All others were considered as failures. Results: Overall in Group I, 53% and 47% of the patients and in Group II, 59% and 58% of the patients, showed significant improvement with reduction in pain scores and disability index at 12 months and 24 months. In contrast, in the successful groups, significant pain relief and improvement in function were observed in 70% and 62% of Group I at one and 2 years; in 75% and 69% of Group II at one and 2 years. The results in the successful group showed that at the end of the first year patients experienced approximately 38 weeks of relief and at the end of 2 years Group I had 62 weeks and Group II had 68 weeks of relief. Overall total relief for 2 years was 48 weeks in Group I and 54 weeks in Group II. The average procedures in the successful groups were at 4 in one year and 6 at

  1. Veno-venous extracorporeal membrane oxygenation using a double-lumen bi-caval cannula for severe respiratory failure post total artificial heart implantation.

    PubMed

    Miessau, J; Yang, Q; Unai, S; Entwistle, J W C; Cavarocchi, N C; Hirose, H

    2015-07-01

    We report a unique utilization of a double-lumen, bi-caval Avalon cannula for veno-venous (VV) extracorporeal membrane oxygenation (ECMO) during placement of a total artificial heart (TAH, SynCardia, Tucson, AZ). A 22-year-old female with post-partum cardiomyopathy was rescued on veno-arterial (VA) ECMO because of cardiogenic shock. The inability to wean ECMO necessitated implantation of the TAH as a bridge to transplant. In addition, the patient continued to have respiratory failure and concomitant VV ECMO was planned with the implant. During TAH implantation, the Avalon cannula was placed percutaneously from the right internal jugular vein into the inferior vena cava (IVC) under direct vision while the right atrium was open. During VV ECMO support, adequate flows on both ECMO and TAH were maintained without adverse events. VV ECMO was discontinued, without reopening the chest, once the patient's respiratory failure improved. However, the patient subsequently developed a profound respiratory acidosis and required VV ECMO for CO2 removal. The Avalon cannula was placed in the femoral vein to avoid accessing the internal jugular vein and risking damage to the TAH. The patient's oxygenation eventually improved and the cannula was removed at the bedside. The patient was supported for 22 days on VV ECMO and successfully weaned from the ventilator prior to her orthotropic heart transplantation. PMID:25239275

  2. New Insights into the Post-Translational Regulation of DNA Damage Response and Double-Strand Break Repair in Caenorhabditis elegans

    PubMed Central

    Kim, Hyun-Min; Colaiácovo, Monica P.

    2015-01-01

    Although a growing number of studies have reported the importance of SUMOylation in genome maintenance and DNA double-strand break repair (DSBR), relevant target proteins and how this modification regulates their functions are yet to be clarified. Here, we analyzed SUMOylation of ZTF-8, the homolog of mammalian RHINO, to test the functional significance of this protein modification in the DSBR and DNA damage response (DDR) pathways in the Caenorhabditis elegans germline. We found that ZTF-8 is a direct target for SUMOylation in vivo and that its modification is required for DNA damage checkpoint induced apoptosis and DSBR. Non-SUMOylatable mutants of ZTF-8 mimic the phenotypes observed in ztf-8 null mutants, including reduced fertility, impaired DNA damage repair, and defective DNA damage checkpoint activation. However, while mutants for components acting in the SUMOylation pathway fail to properly localize ZTF-8, its localization is not altered in the ZTF-8 non-SUMOylatable mutants. Taken together, these data show that direct SUMOylation of ZTF-8 is required for its function in DSBR as well as DDR but not its localization. ZTF-8’s human ortholog is enriched in the germline, but its meiotic role as well as its post-translational modification has never been explored. Therefore, our discovery may assist in understanding the regulatory mechanism of this protein in DSBR and DDR in the germline. PMID:25819793

  3. A Randomised, Double-Blind, Placebo-Controlled Trial of Actovegin in Patients with Post-Stroke Cognitive Impairment: ARTEMIDA Study Design

    PubMed Central

    Guekht, Alla; Skoog, Ingmar; Korczyn, Amos D.; Zakharov, Vladimir; Eeg, Martin; Vigonius, Ulf

    2013-01-01

    Background No drug treatment to date has shown convincing clinical evidence of restoring cognitive function or preventing further decline after stroke. The ongoing ARTEMIDA study will evaluate the efficacy and safety of Actovegin for the symptomatic treatment of post-stroke cognitive impairment (PSCI) and will explore whether Actovegin has any disease-modifying effect by assessing whether any changes are sustained after treatment. Design ARTEMIDA is a 12-month, multicentre trial in patients (planned a total of 500, now recruited) with cognitive impairment following ischaemic stroke. The study consists of a baseline screening (≤7 days after stroke), after which eligible patients are randomised to Actovegin (2,000 mg/day for up to 20 intravenous infusions followed by 1,200 mg/day orally) or placebo for a 6-month double-blind treatment period. Patients will be followed up for a further 6 months, during which time they will be treated in accordance with standard clinical practice. The primary study endpoint is change from baseline in the Alzheimer's Disease Assessment Scale, cognitive subscale, extended version. Secondary outcomes include: Montreal Cognitive Assessment; dementia diagnosis (ICD-10); National Institutes of Health Stroke Scale; Barthel Index; EQ-5D; Beck Depression Inventory, version II, and safety. Conclusion There is a clear need for effective treatments for PSCI. ARTEMIDA should provide important insights into the use of a novel drug therapy for PSCI. PMID:24516413

  4. Effect of NR-Salacia on post-prandial hyperglycemia: A randomized double blind, placebo-controlled, crossover study in healthy volunteers

    PubMed Central

    Koteshwar, Pravina; Raveendra, Kadur Ramamurthy; Allan, Joseph Joshua; Goudar, Krishnagouda Shankargouda; Venkateshwarlu, Kudiganti; Agarwal, Amit

    2013-01-01

    Background: Salacia chinensis (S. chinensis) is widely distributed in India and Sri Lanka. Most of the species of genus Salacia are known to have effects on blood glucose levels; however, the effects of S. chinensis on glucose levels are seldom reported. Objective: To evaluate the oral hypoglycemic activity of NR- Salacia (1000 mg extract of S. chinensis) in healthy adults. Materials and Methods: Randomized, double-blind, placebo-controlled, cross-over study was conducted in healthy volunteers. Single dose of NR-Salacia (1000 mg extract of Salacia chinensis) and placebo were administered before carbohydrate-rich diet. A 6-point plasma glucose profile was performed at different time intervals up to 180 min. Results: NR-Salacia treatment significantly lowered plasma glucose level at 90 min, and the percentage reduction in glucose concentration was found to be 13.32 as compared to placebo group. A 33.85% decrease in the plasma glucose positive incremental area under curve (AUC) (0 to 180 min) was observed in comparison to placebo. No adverse events were recorded throughout the study period, except for some mild cases of abdominal discomforts like cramping and distention, vomiting, and headache in both placebo and NR-Salacia-treated groups. Conclusion: The study findings revealed that NR-Salacia lowered the post-prandial plasma glucose levels after a carbohydrate-rich meal and can be used as an oral hypoglycemic agent. PMID:24124287

  5. Suicidal Thoughts and Reasons for Living in Hospitalized Patients With Severe Depression: Post-Hoc Analyses of a Double-Blind Randomized Trial of Duloxetine

    PubMed Central

    Desaiah, Durisala; Raskin, Joel; Cairns, Victoria; Brecht, Stephan

    2014-01-01

    Objective: To evaluate suicidal thoughts in relationship to depressive symptom severity and reasons for living in patients hospitalized for major depressive disorder (MDD). Method: A post hoc analysis was conducted of a randomized, double-blind, parallel-group trial involving hospitalized patients with MDD (DSM-IV criteria) who received duloxetine 60 mg once daily or duloxetine 60 mg twice daily for 8 weeks. After 4 weeks, the dose for nonresponders receiving 60 mg once daily could be increased to 60 mg twice daily (double-blind). The study was conducted between February 9, 2007, and August 26, 2008 at 43 centers in 4 countries across Europe and South Africa. Suicidal thoughts were assessed with Montgomery-Asberg Depression Rating Scale (MADRS) item 10, depression severity was assessed with the 6-item Hamilton Depression Rating Scale and the Clinical Global Impressions–Severity of Illness scale, and protective factors were assessed with the patient-rated Reasons for Living Inventory (RFL) assessing 6 domains. Descriptive statistics, correlation, and linear regression analysis were performed. Results: At baseline, patients (N = 336) had varying severity of suicidal thoughts: 18% had a score ≥ 4. The proportion of patients with a score ≥ 4 decreased to 7% at week 1 and 1% at week 8 of treatment. The RFL scores at baseline were lower in patients with higher baseline suicidal thoughts and increased significantly during treatment (P < .0001). A regression model revealed that only 16% of variance in baseline total RFL score is explained by the different MADRS items. Eight patients had suicidal behavior or ideation recorded as an adverse event during the study; no consistent pattern was found in the different psychometric scores either at baseline or at the visit preceding the suicidal behavior/ideation. Conclusions: Suicidality rapidly decreased in hospitalized patients with severe depression treated with duloxetine. The RFL scores were low at baseline but

  6. Effect of lurasidone dose on cognition in patients with schizophrenia: post-hoc analysis of a long-term, double-blind continuation study.

    PubMed

    Harvey, Philip D; Siu, Cynthia O; Ogasa, Masaaki; Loebel, Antony

    2015-08-01

    We previously reported that treatment with 160mg/d of lurasidone improved cognitive performance in a manner superior to placebo, quetiapine XR 600mg/d, and lurasidone 80mg/d, based on a 6-week randomized trial of patients with an acute exacerbation of schizophrenia. The objective of this post-hoc analysis was to explore the cognitive and functional performance of patients whose final doses of lurasidone were 40/80mg/d, 120mg/d, and 160mg/d compared to quetiapine XR 200-800mg/d (QXR) during a 6-month, double-blind continuation study that followed a short-term trial. Subjects who received final doses of lurasidone 120mg/d (n=77) and 160mg/d (n=49) showed significantly greater improvement in overall cognitive performance compared to QXR (n=85) at week 32 (month 6 of the extension study), while those on last doses of 40/80mg/d (n=25) showed a trend towards significance at week 32. Mean changes in neurocognitive composite z-score from pre-treatment baseline were significant for the 3 lurasidone final dose groups at both weeks 19 and 32, with composite change scores of z=1.53, z=1.43, and z=1.34 for the lurasidone 40/80mg/d, 120mg/d, and 160mg/d, respectively, at week 32. In contrast, the composite change score was not statistically significant in the overall quetiapine group (z=0.46), with none of the individual quetiapine doses showing any significant improvement. Functional capacity scores improved in all treatment groups. Our findings indicate improved cognitive performance in patients treated with each of the flexible doses of lurasidone 40-160mg/d, compared to quetiapine XR 200-800mg/d. All doses of lurasidone were superior to all doses of quetiapine for cognitive performance. PMID:26117157

  7. The effect of herbal extract (EstroG-100) on pre-, peri- and post-menopausal women: a randomized double-blind, placebo-controlled study.

    PubMed

    Chang, Albert; Kwak, Bo-Yeon; Yi, Kwontaek; Kim, Jae Soo

    2012-04-01

    This clinical research study was designed to evaluate the efficacy of a new herbal product, EstroG-100, containing a mixture of standardized extracts of Cynanchum wilfordii, Phlomis umbrosa and Angelica gigas, on menopausal symptoms. This randomized double-blind, placebo-controlled trial was performed for 12 weeks with 64 pre-, peri- and postmenopausal White Hispanic, White non-Hispanic and African American women who were randomly allocated to either the EstroG-100 group (n = 31) or the placebo group (n =  33). Primary end-points were the mean change in scores of the Kupperman menopause index (KMI) that evaluates 11 symptoms, and the mean change in scores of vaginal dryness. The mean KMI score was significantly reduced in the EstroG-100 group from 29.5 ± 7.4 at baseline to 11.3 ± 5.8 (p < 0.01) compared with change of the placebo group (29.2 ± 6.6 at baseline vs 23.7 ± 7.7 at week 12). The constituting symptoms of vasomotor, paresthesia, insomnia, nervousness, melancholia, vertigo, fatigue and rheumatic pain were significantly improved in the EstroG-100 group in comparison with the placebo group (p < 0.05). Statistically significant improvement in vaginal dryness in the EstroG-100 group was also observed compared with that of the placebo group (p < 0.05). In conclusion, EstroG-100 significantly improved the menopausal symptoms of pre-, peri- and post-menopausal women without weight gain or any serious side effects. PMID:21887807

  8. Wrinkle reduction in post-menopausal women consuming a novel oral supplement: a double-blind placebo-controlled randomized study

    PubMed Central

    Jenkins, G; Wainwright, L J; Holland, R; Barrett, K E; Casey, J

    2014-01-01

    Synopsis Objective The maintenance of youthful skin appearance is strongly desired by a large proportion of the world's population. The aim of the present study was therefore to evaluate the effect on skin wrinkling, of a combination of ingredients reported to influence key factors involved in skin ageing, namely inflammation, collagen synthesis and oxidative/UV stress. A supplemented drink was developed containing soy isoflavones, lycopene, vitamin C and vitamin E and given to post-menopausal women with a capsule containing fish oil. Method We have performed a double-blind randomized controlled human clinical study to assess whether this cocktail of dietary ingredients can significantly improve the appearance of facial wrinkles. Results We have shown that this unique combination of micronutrients can significantly reduce the depth of facial wrinkles and that this improvement is associated with increased deposition of new collagen fibres in the dermis. Conclusion This study demonstrates that consumption of a mixture of soy isoflavones, lycopene, vitamin C, vitamin E and fish oil is able to induce a clinically measureable improvement in the depth of facial wrinkles following long-term use. We have also shown, for the first time with an oral product, that the improvement is associated with increased deposition of new collagen fibres in the dermis. Résumé Objectif Le maintien de l'apparence d'une peau jeune est vivement souhaité par une grande proportion de la population mondiale. L'objectif de la présente étude était donc d'évaluer l'effet sur les rides de la peau, d'une combinaison d'ingrédients rapportés à influer sur les facteurs clés impliqués dans le vieillissement de la peau, à savoir l'inflammation, la synthèse du collagène et le stress oxydatif / UV. Une boisson supplémentée a été élaborée contenant des isoflavones de soja, le lycopène, la vitamine C et la vitamine E et donnée aux femmes ménopausées avec une capsule contenant de l

  9. Effect of low-level laser therapy on the post-surgical inflammatory process after third molar removal: study protocol for a double-blind randomized controlled trial

    PubMed Central

    2013-01-01

    Background Low-level laser therapy (LLLT) has been shown to modulate the inflammatory process without adverse effects , by reducing pain and swelling and promoting the repair of damaged tissues. Because pain, swelling and muscle spasm are complications found in virtually all patients following oral surgery for the removal of impacted teeth, this model has been widely used to evaluate the effects of LLLT on the inflammatory process involving bone and, connective tissue and the muscles involved in mastication. Methods/Design After meeting the eligibility criteria, 60 patients treated at a Specialty Dental Center for the removal of impacted lower third molars will be randomly divided into five groups according to the type of laser therapy used at the end of surgery (intraoral irradiation with 660 nm laser; extraoral irradiation with 660 nm laser; intraoral irradiation with 808 nm laser; extraoral irradiation with 808 nm laser and no irradiation). To ensure that patients are blinded to the type of treatment they are receiving, the hand piece of the laser apparatus will be applied both intraorally and extraorally to all participants, but the device will be turned on only at the appropriate time, as determined by the randomization process. At 2 and 7 days after surgery, the patients will be evaluated by three blinded evaluators who will measure of swelling, mouth opening (muscle spasm evaluation) and pain (using two different pain scales). The 14-item Oral Health Impact Profile (OHIP-14) will be used to assess QOL. All data will be analyzed with respect to the normality of distribution using the Shapiro-Wilk test. Statistically significant differences between the experimental groups will be determined using analysis of variance, followed by a suitable post hoc test, when necessary. The significance level will be set at α = 0.05. Discussion The lack of standardization in studies with regard to the samples, methods and LLLT parameters complicates the

  10. Intravenous dexamethasone versus ketamine gargle versus intravenous dexamethasone combined with ketamine gargle for evaluation of post-operative sore throat and hoarseness: A randomized, placebo-controlled, double blind clinical trial

    PubMed Central

    Safavi, Mohammadreza; Honarmand, Azim; Fariborzifar, Arghavan; Attari, Mohammadali

    2014-01-01

    Background: Sore throat and hoarseness are the most frequent subjective complaints after tracheal intubation for general anesthesia. We conducted a prospective, randomized, double-blind, placebo controlled study to evaluate the efficacy of intravenous (IV) dexamethasone plus ketamine gargle for reducing the incidence and severity of post-operative sore throat (POST) and hoarseness. Materials and Methods: 140 patients (aged 16-65 year) scheduled for elective surgery were enrolled. Patients were randomly allocated into four groups of 35 subjects each: Group K, gargled 40 mg ketamine in 30 ml saline; Group D, were infused 0.2 mg/kg IV dexamethasone; Group KD, gargled 40 mg ketamine in 30 ml saline plus 0.2 mg/kg IV dexamethasone; Group P (placebo) that received saline (gargle and IV). POST was graded at 0, 2, 4, 8, 16 and 24 h after operation on a four-point scale (0-3). Results: The incidence and severity of POST were significantly lower in Group KD, compared with the other groups at all times after tracheal extubation for up to 24 h (P < 0.05). Also the incidence and severity of hoarseness were significantly lower in each Groups of KD and K and D compared with group placebo (P < 0.05). Conclusion: The prophylactic use of 0.2 mg/kg of IV dexamethasone plus ketamine gargle significantly reduced the incidence and severity of POST compared with using each of these drugs alone or using placebo. PMID:25371869

  11. Effect of ondansetron on prevention of post-induction hypotension in elderly patients undergoing general anesthesia: A randomized, double-blind placebo-controlled clinical trial

    PubMed Central

    Golparvar, Mohammad; Saghaei, Mahmoud; Saadati, Mohammad Ali; Farsaei, Shadi

    2015-01-01

    Background: Elderly patients are susceptible to post-induction hypotension. Volume loading and vasopressors for prevention of hypotension in elderly patients may increase perioperative cardiovascular risks. Ondansetron by blocking Bezold–Jarisch reflex (BJR) through inhibition of serotonin receptors has been effective in the prevention of post-spinal hypotension, and bradycardia. Bradycardia frequently accompanies post-induction hypotension in elderly patients, which signifies a possible preventing role for ondansetron. No previous study has evaluated the prophylactic effects of ondansetron for the prevention of post-induction hypotension. Materials and Methods: In this randomized placebo-controlled clinical trial, ondansetron 4 mg was given intravenously to 65 elderly patients, 20 min before induction of general anesthesia, and the rate of post-induction hypotension defined as 25% or more reduction in mean arterial blood pressure, compared with a placebo groups. Results: A total of 114 patients completed the study (58 in ondansetron and 56 in the placebo group). Proportions of post-induction hypotension were 9 (16%) and 25 (45%) in ondansetron and placebo groups, respectively, (P = 0.001). Forty-five patients (40%) developed bradycardia. Rates of bradycardia were not significantly different between two groups. Conclusions: The results of this study show the effectiveness of intravenous ondansetron for prevention of post-induction hypotension in elderly patients. The mechanism of this effect largely is unknown. Role of ondansetron for prevention of post-induction hypotension may not fully understandable by its interaction with BJR, as has been shown in post-spinal hypotension. PMID:26543450

  12. A double-blind, placebo-controlled intervention trial of 3 and 10 mg sublingual melatonin for post-concussion syndrome in youths (PLAYGAME): study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background By the age of sixteen, one in five children will sustain a mild traumatic brain injury also known as concussion. Our research found that one in seven school children with mild traumatic brain injury suffer post-concussion syndrome symptoms for three months or longer. Post-concussion syndrome is associated with significant disability in the child and his/her family and yet there are no evidence-based medical treatments available. Melatonin has several potential mechanisms of action that could be useful following mild traumatic brain injury, including neuroprotective effects. The aim of this study is to determine if treatment with melatonin improves post-concussion syndrome in youths following mild traumatic brain injury. Our hypothesis is that treatment of post-concussion syndrome following mild traumatic brain injury with 3 or 10 mg of sublingual melatonin for 28 days will result in a decrease in post-concussion syndrome symptoms compared with placebo. Methods/Design Ninety-nine youths with mild traumatic brain injury, aged between 13 and 18 years, who are symptomatic at 30 days post-injury will be recruited. This study will be conducted as a randomized, double blind, placebo-controlled superiority trial of melatonin. Three parallel treatment groups will be examined with a 1:1:1 allocation: sublingual melatonin 3 mg, sublingual melatonin 10 mg, and sublingual placebo. Participants will receive treatment for 28 days. The primary outcome is a change on the Post-Concussion Symptom Inventory (Parent and Youth). The secondary outcomes will include neurobehavioral function, health-related quality of life and sleep. Neurophysiological and structural markers of change, using magnetic resonance imaging techniques and transcranial magnetic stimulation, will also be investigated. Discussion Melatonin is a safe and well-tolerated agent that has many biological properties that may be useful following a traumatic brain injury. This study will determine whether it is a

  13. A Systems Biology Approach Investigating the Effect of Probiotics on the Vaginal Microbiome and Host Responses in a Double Blind, Placebo-Controlled Clinical Trial of Post-Menopausal Women

    PubMed Central

    Bisanz, Jordan E.; Seney, Shannon; McMillan, Amy; Vongsa, Rebecca; Koenig, David; Wong, LungFai; Dvoracek, Barbara; Gloor, Gregory B.; Sumarah, Mark; Ford, Brenda; Herman, Dorli; Burton, Jeremy P.; Reid, Gregor

    2014-01-01

    A lactobacilli dominated microbiota in most pre and post-menopausal women is an indicator of vaginal health. The objective of this double blinded, placebo-controlled crossover study was to evaluate in 14 post-menopausal women with an intermediate Nugent score, the effect of 3 days of vaginal administration of probiotic L. rhamnosus GR-1 and L. reuteri RC-14 (2.5×109 CFU each) on the microbiota and host response. The probiotic treatment did not result in an improved Nugent score when compared to when placebo. Analysis using 16S rRNA sequencing and metabolomics profiling revealed that the relative abundance of Lactobacillus was increased following probiotic administration as compared to placebo, which was weakly associated with an increase in lactate levels. A decrease in Atopobium was also observed. Analysis of host responses by microarray showed the probiotics had an immune-modulatory response including effects on pattern recognition receptors such as TLR2 while also affecting epithelial barrier function. This is the first study to use an interactomic approach for the study of vaginal probiotic administration in post-menopausal women. It shows that in some cases multifaceted approaches are required to detect the subtle molecular changes induced by the host to instillation of probiotic strains. Trial Registration ClinicalTrials.gov NCT02139839 PMID:25127240

  14. Pre- and Post-Head Processing for Single- and Double-Scrambled Sentences of a Head-Final Language as Measured by the Eye Tracking Method

    ERIC Educational Resources Information Center

    Tamaoka, Katsuo; Asano, Michiko; Miyaoka, Yayoi; Yokosawa, Kazuhiko

    2014-01-01

    Using the eye-tracking method, the present study depicted pre- and post-head processing for simple scrambled sentences of head-final languages. Three versions of simple Japanese active sentences with ditransitive verbs were used: namely, (1) SO[subscript 1]O[subscript 2]V canonical, (2) SO[subscript 2]O[subscript 1]V single-scrambled, and (3)…

  15. Preoperative evaluation of stage T3, central-type non-small cell lung cancer with double sleeve lobectomy under complete video-assisted thoracoscopic surgery using spiral computed tomography post-processing techniques

    PubMed Central

    Guan, Yubao; Huang, Jun; Xia, Tingting; You, Xiaoting; He, Jiaxi

    2016-01-01

    Background To investigate the estimated value of spiral computed tomography (CT) post-processing techniques in preoperative stage T3, central-type non-small cell lung cancer (NSCLC) with double sleeve lobectomy under complete video-assisted thoracoscopic surgery (c-VATS). Methods Preoperative clinical date and CT reconstructed data of 10 patients who underwent double sleeve lobectomy with upper lobe stage T3, central-type NSCLC were retrospectively analysed and compared to surgical pathological results and cross-sectional CT data. The diagnostic criterions of tumour invasion of pulmonary artery and bronchus were divided into five grades, which included estimation of upper lobe pulmonary arteries and bronchi (40 branches, respectively). Results The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of cross-sectional CT images of pulmonary artery tumour invasion were 78.57%, 58.33%, 81.48%, 53.85%, and 72.50%, respectively, while the respective values for CT reconstructed images were 93.55%, 87.50%, 96.67%, 70.00%, and 90.00%, showing statistical significance (χ2=4.021, P=0.045). Similarly, the evaluate, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of cross-sectional CT images of bronchial tumour invasion were 82.76%, 45.45%, 80.00%, 50.00%, and 72.50%, respectively, while the respective values for CT reconstructed images were 97.06%, 66.67%, 94.29%, 80.00%, 92.50%; these results were also statistically significant (χ2=5.541, P=0.019). Conclusions The sensitivity, specificity, and diagnostic accuracy of the spiral CT post-processing techniques were better than cross-sectional CT images in estimating the extent of tumour invasion in the pulmonary arteries and bronchi of central-type NSCLC. CT post-processing techniques are essential tools in preoperative examination and operative method selection of central-type lung cancer with double sleeve

  16. Total Iron Absorption by Young Women from Iron-Biofortified Pearl Millet Composite Meals Is Double That from Regular Millet Meals but Less Than That from Post-Harvest Iron-Fortified Millet Meals123

    PubMed Central

    Cercamondi, Colin I.; Egli, Ines M.; Mitchikpe, Evariste; Tossou, Felicien; Zeder, Christophe; Hounhouigan, Joseph D.; Hurrell, Richard F.

    2013-01-01

    Iron biofortification of pearl millet (Pennisetum glaucum) is a promising approach to combat iron deficiency (ID) in the millet-consuming communities of developing countries. To evaluate the potential of iron-biofortified millet to provide additional bioavailable iron compared with regular millet and post-harvest iron-fortified millet, an iron absorption study was conducted in 20 Beninese women with marginal iron status. Composite test meals consisting of millet paste based on regular-iron, iron-biofortified, or post-harvest iron-fortified pearl millet flour accompanied by a leafy vegetable sauce or an okra sauce were fed as multiple meals for 5 d. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes. Fractional iron absorption from test meals based on regular-iron millet (7.5%) did not differ from iron-biofortified millet meals (7.5%; P = 1.0), resulting in a higher quantity of total iron absorbed from the meals based on iron-biofortified millet (1125 vs. 527 μg; P < 0.0001). Fractional iron absorption from post-harvest iron-fortified millet meals (10.4%) was higher than from regular-iron and iron-biofortified millet meals (P < 0.05 and P < 0.01, respectively), resulting in a higher quantity of total iron absorbed from the post-harvest iron-fortified millet meals (1500 μg; P < 0.0001 and P < 0.05, respectively). Results indicate that consumption of iron-biofortified millet would double the amount of iron absorbed and, although fractional absorption of iron from biofortification is less than that from fortification, iron-biofortified millet should be highly effective in combatting ID in millet-consuming populations. PMID:23884388

  17. Design for Double Rainbow

    ERIC Educational Resources Information Center

    Thomas, Lisa Carlucci

    2011-01-01

    Rare is the inspirational, spontaneous, transformative moment shared among 20 million people. In the summer of 2010, people around the world were moved by the sighting of a double rainbow--almost a triple rainbow--"all the way across the sky" in Yosemite National Park. Caught on video and posted to by YouTube by Paul Vasquez in January 2010, the…

  18. Comparison of pre- vs. post-incisional caudal bupivacaine for postoperative analgesia in unilateral pediatric herniorrhaphy: A double-blind randomized clinical trial

    PubMed Central

    Sajedi, Parvin; Yaraghi, Ahmad; Zadeh, Mohammad Taher Dehdari

    2011-01-01

    Introduction: This study was designed to evaluate the pre- vs. post-incisional analgesic efficacy of bupivacaine administered caudally in children undergoing unilateral hernia repair. Methods: Fifty children aged 6 months to 6 years were included in the study. Children were divided blindly between the two groups to receive pre- vs. post-incisional caudal bupivacaine. The preincisional group received 1 ml/kg of 0.125% bupivacaine caudally after induction of anesthesia and the postincisional group received the same dose caudally at the end of surgery. Heart rate, SaO2, end tidal CO2, and noninvasive arterial blood pressure were recorded every 10 min. The duration of surgery, extubation time, and duration of recovery period were also recorded. The pain scores were measured with using an Oucher chart in the recovery room, 2, 4, 6, 12, and 24 h after surgery. Time to first analgesia, numbers of supplementary analgesics required by each child in a 24-h period and total analgesic consumptions were recorded. Any local and systemic complications were recorded. Quantitative data were compared using a two-tailed t-test. Sex distribution and frequency of acetaminophen consumption were measured using χ2 test. P < 0.05 was considered statistically significant. Results: The Oucher pain scale at 4, 6, 12, and 24 h after surgery, the total analgesic consumption and the numbers of demand for supplemental acetaminophen were lower statistically in preincisional group (P < 0.05). Extubation time and duration were higher in preincisional group (P < 0.05). Mean changes of heart rates were statistically lower during the anesthesia period and recovery time in preincisional group (P < 0.05). Conclusion: Preincisional caudal analgesia with a single injection of 0.125% bupivacaine is more effective than the postincisional one for postoperative pain relief and analgesic consumption in unilateral pediatric herniorrhaphy. PMID:21804795

  19. A NUMERICAL METHOD FOR STUDYING SUPER-EDDINGTON MASS TRANSFER IN DOUBLE WHITE DWARF BINARIES

    SciTech Connect

    Marcello, Dominic C.; Tohline, Joel E. E-mail: tohline@phys.lsu.edu

    2012-04-01

    We present a numerical method for the study of double white dwarf (DWD) binary systems at the onset of super-Eddington mass transfer. We incorporate the physics of ideal inviscid hydrodynamical flow, Newtonian self-gravity, and radiation transport on a three-dimensional uniformly rotating cylindrical Eulerian grid. Care has been taken to conserve the key physical quantities such as angular momentum and energy. Our new method conserves total energy to a higher degree of accuracy than other codes that are presently being used to model mass transfer in DWD systems. We present the results of verification tests and simulate the first 20 + orbits of a binary system of mass ratio q 0.7 at the onset of dynamically unstable direct impact mass transfer. The mass transfer rate quickly exceeds the critical Eddington limit by many orders of magnitude, and thus we are unable to model a trans-Eddington phase. It appears that radiation pressure does not significantly affect the accretion flow in the highly super-Eddington regime. An optically thick common envelope forms around the binary within a few orbits. Although this envelope quickly exceeds the spatial domain of the computational grid, the fraction of the common envelope that exceeds zero gravitational binding energy is extremely small, suggesting that radiation-driven mass loss is insignificant in this regime. It remains to be seen whether simulations that capture the trans-Eddington phase of such flows will lead to the same conclusion or show that substantial material gets expelled.

  20. A comparison between subpleural patient-controlled analgesia by bupivacaine and intermittent analgesia in post-operative thoracotomy: A double-blind randomized clinical trial*

    PubMed Central

    Goharian, Vahid; Tabatabaee, Sayyed Abbas; MozafarHashemi, Sayyed; Mohajery, Gholamreza; Ramezani, Mohammad Arash; Shabani, Fatemeh; MotevalliEmami, Zahra

    2011-01-01

    BACKGROUND: The efficacy of subpleural analgesia to reduce postoperative pain intensity in patients after lateral thoracotomy is controversial. In this study, we demonstrated the efficacy of two types of subpleural analgesia. METHODS: This prospective, controlled, randomized, double-blind trial was performed in Department of Thoracic Surgery of Alzahra Hospital associated with Isfahan University of Medical Sciences from June 2009 until August 2010. After posterolateral thoracotomy and admission to the ICU, patients were randomly assigned into two groups of subpleural patient-controlled analgesia (SPCA) (0.02 cc/kg/h of 0.5% bupivacaine) and subpleural intermittent analgesia (SIA) (0.1cc/kg/6h of 0.5% bupivacaine). The data regarding age, sex, visual analog scale (VAS) (at 8, 16 and 24 hours after initiation of analgesia), morphine consumption, systemic adverse effects, length of ICU and hospital stay, complications, public health service (PHS) criteria, and cost was recorded. Data was analyzed by Mann-Whitney U-test, repeated measured test, chi-square test and the Fisher's exact test. A p < 0.05 was considered significant. RESULTS: The study population consisted of 90 patients. There were no significant differences in sex, age, weight, intraoperative analgesics, duration of one-lung ventilation, and adverse effects between the SPCA and SIA groups. Although pain scores were significantly reduced at 16 hours after the first subpleural instillation of bupivacaine 0.5% with patient-controlled analgesia, comparison between mean pain scores in the two groups at 8 and 24 hours after the first subpleural instillation of bupivacaine 0.5% revealed no significant difference. In addition, no significant difference was found in VAS scores at the three evaluated times (p < 0.05). CONCLUSIONS: Optimal use of SPCA bupivacaine for postoperative pain treatment is more effective in pain reduction than SIA bupivacaine. The consumption rate of opioid and bupivacaine was also decreased

  1. Today a Duo, but Once a Trio? The Double White Dwarf HS 2220+2146 May Be a Post-blue Straggler Binary

    NASA Astrophysics Data System (ADS)

    Andrews, Jeff J.; Agüeros, Marcel; Brown, Warren R.; Gosnell, Natalie M.; Gianninas, A.; Kilic, Mukremin; Koester, Detlev

    2016-09-01

    For sufficiently wide orbital separations a, the two members of a stellar binary evolve independently. This implies that in a wide double white dwarf (DWD), the more massive WD should always be produced first, when its more massive progenitor ends its main sequence (MS) life, and should therefore be older and cooler than its companion. The bound, wide DWD HS 2220+2146 (a≈ 500 au) does not conform to this picture: the more massive WD is the younger and hotter of the pair. We show that this discrepancy is unlikely to be due to past mass-transfer phases or to the presence of an unresolved companion. Instead, we propose that HS 2220+2146 formed through a new wide DWD evolutionary channel involving the merger of the inner binary in a hierarchical triple system. The resulting blue straggler and its wide companion then evolved independently, forming the WD pair seen today. Although we cannot rule out other scenarios, the most likely formation channel has the inner binary merging while both stars are still on the MS. This provides us with the tantalizing possibility that Kozai–Lidov oscillations may have played a role in the inner binary’s merger. Gaia may uncover hundreds more wide DWDs, leading to the identification of other systems like HS 2220+2146. There are already indications that other WD systems may have been formed through different, but related, hierarchical triple evolutionary scenarios. Characterizing these populations may allow for thorough testing of the efficiency with which Kozai–Lidov oscillations induce stellar mergers.

  2. The long and the short of it: modelling double neutron star and collapsar Galactic dynamics

    NASA Astrophysics Data System (ADS)

    Kiel, Paul D.; Hurley, Jarrod R.; Bailes, Matthew

    2010-07-01

    Understanding the nature of galactic populations of double compact binaries (where both stars are a neutron star or black hole) has been a topic of interest for many years, particularly the coalescence rate of these binaries. The only observed systems thus far are double neutron star systems containing one or more radio pulsars. However, theorists have postulated that short-duration gamma-ray bursts may be evidence of coalescing double neutron star or neutron star-black hole binaries, while long-duration gamma-ray bursts are possibly formed by tidally enhanced rapidly rotating massive stars that collapse to form black holes (collapsars). The work presented here examines populations of double compact binary systems and tidally enhanced collapsars. We make use of BINPOP and BINKIN, two components of a recently developed population synthesis package. Results focus on correlations of both binary and spatial evolutionary population characteristics. Pulsar and long-duration gamma-ray burst observations are used in concert with our models to draw the conclusions that (i) double neutron star binaries can merge rapidly on time-scales of a few million years (much less than that found for the observed double neutron star population), (ii) common-envelope evolution within these models is a very important phase in double neutron star formation and (iii) observations of long gamma-ray burst projected distances are more centrally concentrated than our simulated coalescing double neutron star and collapsar Galactic populations. Better agreement is found with dwarf galaxy models although the outcome is strongly linked to the assumed birth radial distribution. The birth rate of the double neutron star population in our models ranges from 4 to 160 Myr-1 and the merger rate ranges from 3 to 150 Myr-1. The upper and lower limits of the rates result from including electron-capture supernova kicks to neutron stars and decreasing the common-envelope efficiency, respectively. Our double

  3. Double-helix stellarator

    SciTech Connect

    Moroz, P.E.

    1997-09-01

    A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.

  4. Patient Background Factors Affecting the Therapeutic Outcomes in Response to Eszopiclone in Adult Patients with Chronic Insomnia: A Post Hoc Analysis of a Double-Blind Phase III Study in Japan

    PubMed Central

    Inoue, Yuichi; Kamijo, Atsushi; Nagai, Reiko

    2015-01-01

    Study Objective: To identify whether baseline demographic factors or subjective sleep variables are associated with the outcomes following treatment with eszopiclone using data from a recent randomized controlled trial of 78 Japanese subjects with insomnia who were treated with 2 mg eszopiclone per day. Methods: We performed a post hoc analysis of factors including sleep latency (SL), wake time after sleep onset (WASO) (both assessed via sleep diaries), and several demographic variables. Subjects with a SL or WASO > 30 min at baseline and with evaluable SL/WASO data at Week 4 were included in SL and WASO remitter analyses, respectively; those with a SL or WASO ≤ 30 min at Week 4 were defined as SL or WASO remitters, respectively. Threshold baseline SL and WASO values for identification of remitters were determined. Results: No relationships between subjectively assessed therapeutic outcomes and demographic factors were identified. Patients with shorter SL and lower WASO values at baseline showed better outcomes following treatment with eszopiclone in terms of SL and WASO changes, respectively. Baseline SL of 75 min and baseline WASO of 80 min were selected as arbitrary cutoff values for determination of SL and WASO remitters/non-remitters, respectively. Conclusions: These findings may help clinicians to predict their patients' outcomes in response to standard doses of eszopiclone in clinical practice. Citation: Inoue Y, Kamijo A, Nagai R. Patient background factors affecting the therapeutic outcomes in response to eszopiclone in adult patients with chronic insomnia: a post hoc analysis of a double-blind phase III study in Japan. J Clin Sleep Med 2015;11(10):1171–1178. PMID:26094929

  5. Efficacy and acceptability of atypical antipsychotics for the treatment of post-traumatic stress disorder: a meta-analysis of randomized, double-blind, placebo-controlled clinical trials.

    PubMed

    Liu, Xiao-hui; Xie, Xin-hui; Wang, Ke-yong; Cui, Hong

    2014-11-30

    As some evidences demonstrated that atypical antipsychotics (AA) may be efficacious in treating post-traumatic stress disorder (PTSD), we preformed a meta-analysis of randomized, double-blind, placebo-controlled clinical trials (RCTs) of AAs for the treatment of PTSD. Two hundred and fifty one papers were searched and screened. Eight RCTs met the inclusion criteria. AAs may be superior to placebo in the treatment of PTSD, as indicated by the changes in Clinician Administered PTSD Scale (CAPS) total scores (weighted mean differences (WMD)=-5.89, 95% confidence interval (CI) [-9.21, -2.56], P=0.0005) and also in CAPS subscale intrusion (WMD=-2.58, 95% CI[-3.83, -1.33], P<0.0001 ) and subscale hyperarousal (WMD=-2.94, 95% CI[-5.45, -0.43], P=0.02). The acceptability measured by dropout rates between AAs and placebo showed no statistical difference (OR=1.24, 95%CI [0.78, 1.97], P=0.36). PTSD symptom cluster, especially in intrusion and hyperarousal. However, we should be careful to generalize the conclusion because of the small number of included trails. We expect more RCTs will be done in the future so as to clarify the specific value of AAs for PTSD. PMID:25015709

  6. An ALMA view of the post-AGB object HD 101584

    NASA Astrophysics Data System (ADS)

    Olofsson, H.; Vlemmings, W.; Maercker, M.; Humphreys, E.; Lindqvist, M.; Nyman, L.; Ramstedt, S.

    2016-07-01

    ALMA cycles 1 and 3 observations of CO isotopologues and 1.3mm continuum are used in a study of the circumstellar environment of the binary HD 101584, a post-AGB star and a low-mass companion that is most likely a post-common-envelope-evolution system. These data are supplemented with new information from OH maser emission. It is inferred that the large- scale circumstellar medium has a bipolar hour-glass structure, seen almost pole-on, formed by an energetic, ≥⃒ 150 km s-1, jet. Significant amount of material still resides in the central region. It is proposed that the circumstellar morphology is related to an event which took place ≤⃒ 500 yr ago, possibly a capture event where the companion spiralled in towards the AGB star. Several observed features remain to be explained, and may hint to a more complicated scenario.

  7. Repetitive H-Wave® device stimulation and program induces significant increases in the range of motion of post operative rotator cuff reconstruction in a double-blinded randomized placebo controlled human study

    PubMed Central

    Blum, Kenneth; Chen, Amanda LC; Chen, Thomas JH; Waite, Roger L; Downs, B William; Braverman, Eric R; Kerner, Mallory M; Savarimuthu, Stella M; DiNubile, Nicholas

    2009-01-01

    significant increase in range of motion in positive management of rotator cuff reconstruction, supporting other previous research on HWDS and improvement in function. Interpretation of this preliminary investigation while suggestive of significant increases in Range of Motion of Post -Operative Rotator Cuff Reconstruction, warrants further confirmation in a larger double-blinded sham controlled randomized study. PMID:19874593

  8. Angular Momentum Transport in Double White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Motl, Patrick M.; Tohline, Joel E.; Frank, Juhan

    2006-11-01

    We present simulations of dynamical mass transfer in a double white dwarf binary with an initial mass ratio of 0.4. The binary components are approximated as polytropes of index n = 3/2 and the synchronously rotating, semi-detached equilibrium binary is evolved hydrodynamically with the gravitational potential being computed through the solution of Poisson's equation. Upon initiating deep contact, the mass transfer rate grows by more than an order of magnitude over approximately ten orbits, as would be expected for dynamically unstable mass transfer. However, the mass transfer rate then reaches a peak value, the binary expands and the mass transfer event subsides over approximately 30 orbits. Despite the loss of orbital angular momentum into the spin of the accreting star, we find that the accretor's spin saturates and the binary responds as one would expect for a system with an accretion disk filling a substantial fraction of the accretor's Roche lobe. It appears that double white dwarf binaries may be more resilient against merger than previously anticipated though our simulations do not include radiation forces which may ultimately fill a common envelope which dooms the binary.

  9. What is the ideal dose and power output of low-level laser therapy (810 nm) on muscle performance and post-exercise recovery? Study protocol for a double-blind, randomized, placebo-controlled trial

    PubMed Central

    2014-01-01

    Background Recent studies involving phototherapy applied prior to exercise have demonstrated positive results regarding the attenuation of muscle fatigue and the expression of biochemical markers associated with recovery. However, a number of factors remain unknown, such as the ideal dose and application parameters, mechanisms of action and long-term effects on muscle recovery. The aims of the proposed project are to evaluate the long-term effects of low-level laser therapy on post-exercise musculoskeletal recovery and identify the best dose andapplication power/irradiation time. Design and methods A double-blind, randomized, placebo-controlled clinical trial with be conducted. After fulfilling the eligibility criteria, 28 high-performance athletes will be allocated to four groups of seven volunteers each. In phase 1, the laser power will be 200 mW and different doses will be tested: Group A (2 J), Group B (6 J), Group C (10 J) and Group D (0 J). In phase 2, the best dose obtained in phase 1 will be used with the same distribution of the volunteers, but with different powers: Group A (100 mW), Group B (200 mW), Group C (400 mW) and Group D (0 mW). The isokinetic test will be performed based on maximum voluntary contraction prior to the application of the laser and after the eccentric contraction protocol, which will also be performed using the isokinetic dynamometer. The following variables related to physical performance will be analyzed: peak torque/maximum voluntary contraction, delayed onset muscle soreness (algometer), biochemical markers of muscle damage, inflammation and oxidative stress. Discussion Our intention, is to determine optimal laser therapy application parameters capable of slowing down the physiological muscle fatigue process, reducing injuries or micro-injuries in skeletal muscle stemming from physical exertion and accelerating post-exercise muscle recovery. We believe that, unlike drug therapy, LLLT has a biphasic dose–response pattern. Trial

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

    SciTech Connect

    Ji Suoqing; Fisher, Robert T.; Garcia-Berro, Enrique; Loren-Aguilar, Pablo; Cremer, Pascal; Behrends, Jan

    2013-08-20

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

  11. The efficacy of extended-release levomilnacipran in moderate to severe major depressive disorder: secondary and post-hoc analyses from a randomized, double-blind, placebo-controlled study.

    PubMed

    Montgomery, Stuart A; Mansuy, Lucilla; Ruth, Adam C; Li, Dayong; Gommoll, Carl

    2014-01-01

    Levomilnacipran (1S, 2R-milnacipran) is a potent and selective serotonin and norepinephrine reuptake inhibitor that is Food and Drug Administration approved for once-daily treatment of major depressive disorder in adults. Secondary and post-hoc analyses were carried out on data from a positive 10-week, randomized, double-blind, placebo-controlled, parallel-group, multicenter, proof-of-concept trial (EudraCT Number: 2006-002404-34) on 75 or 100 mg/day levomilnacipran extended release (ER). Included outpatients (18-70 years) met the criteria for a major depressive episode. There was a statistically significant difference in favor of levomilnacipran ER versus placebo in change from baseline to week 10 on every Montgomery Åsberg Depression Rating Scale (MADRS) single item (mixed-effects model for repeated measures; P<0.05) and most Hamilton Depression Rating Scale (HAMD17) single items. Significantly more levomilnacipran ER versus placebo patients (P < 0.05) achieved 'complete' (MADRS ≤ 5; 24 vs. 10%) and 'sustained' (MADRS ≤ 10 in Weeks 4-10; 16 vs. 10%) remission, Sheehan Disability Scale (SDS) response (total score ≤ 12 and each item score ≤ 4; 52 vs. 35%) and remission (total score ≤ 6 and each item score ≤ 2; 26 vs. 17%), and combined symptomatic (MADRS) and functional (SDS) remission (19 vs. 8%). Treatment effects of similar magnitude were observed in the severe depression subgroup (MADRS ≥ 30). These results demonstrate the benefit of levomilnacipran ER over placebo for patients with symptomatic and functional impairment associated with major depressive disorder. PMID:24172160

  12. Randomized, double-blind, active-controlled study evaluating the safety and immunogenicity of three vaccination schedules and two dose levels of AV7909 vaccine for anthrax post-exposure prophylaxis in healthy adults.

    PubMed

    Hopkins, Robert J; Kalsi, Gurdyal; Montalvo-Lugo, Victor M; Sharma, Mona; Wu, Yukun; Muse, Derek D; Sheldon, Eric A; Hampel, Frank C; Lemiale, Laurence

    2016-04-19

    AV7909 vaccine being developed for post-exposure prophylaxis of anthrax disease may require fewer vaccinations and reduced amount of antigen to achieve an accelerated immune response over BioThrax(®) (Anthrax Vaccine Adsorbed). A phase 2, randomized, double-blind, BioThrax vacccine-controlled study was conducted to evaluate the safety and immunogenicity of three intramuscular vaccination schedules and two dose levels of AV7909 in 168 healthy adults. Subjects were randomized at a 4:3:2:4:2 ratio to 5 groups: (1) AV7909 on Days 0/14; (2) AV7909 on Days 0/28; (3) AV7909 on Days 0/14/28; (4) half dose AV7909 on Days 0/14/28; and (5) BioThrax vaccine on Days 0/14/28. Vaccinations in all groups were well tolerated. The incidences of adverse events (AEs) were 79% for AV7909 subjects and 65% for BioThrax subjects; 92% of AV7909 subjects and 87% of BioThrax subjects having AEs reported Grade 1-2 AEs. No serious AEs were assessed as potentially vaccine-related, and no AEs of potential autoimmune etiology were reported. There was no discernible pattern indicative of a safety concern across groups in the incidence or severity of reactogenicity events. Groups 2-4 achieved success for the primary endpoint, demonstrated by a lower 95% confidence limit of the percentage of subjects with protective toxin neutralizing antibody NF50 values (≥0.56) to be ≥40% at Day 63. Group 1 marginally missed the criterion (lower bound 95% confidence limit of 39.5%). Immune responses were above this threshold for Groups 1, 3 and 4 at Day 28 and all groups at Day 42. Further study of an AV7909 two-dose schedule given 2 weeks apart is warranted in light of the favorable tolerability profile and immunogenicity response relative to three doses of BioThrax vaccine, as well as preliminary data from nonclinical studies indicating similar immune responses correlate with higher survival for AV7909 than BioThrax vaccine. PMID:26979136

  13. The gravitational-wave signal generated by a galactic population of double neutron-star binaries

    NASA Astrophysics Data System (ADS)

    Yu, Shenghua; Jeffery, C. Simon

    2015-04-01

    We investigate the gravitational wave (GW) signal generated by a population of double neutron-star (DNS) binaries with eccentric orbits caused by kicks during supernova collapse and binary evolution. The DNS population of a standard Milky Way-type galaxy has been studied as a function of star formation history, initial mass function (IMF) and metallicity and of the binary-star common-envelope ejection process. The model provides birthrates, merger rates and total number of DNS as a function of time. The GW signal produced by this population has been computed and expressed in terms of a hypothetical space GW detector (eLISA) by calculating the number of discrete GW signals at different confidence levels, where `signal' refers to detectable GW strain in a given frequency-resolution element. In terms of the parameter space explored, the number of DNS-originating GW signals is greatest in regions of recent star formation, and is significantly increased if metallicity is reduced from 0.02 to 0.001, consistent with Belczynski et al. Increasing the IMF power-law index (from -2.5 to -1.5) increases the number of GW signals by a large factor. This number is also much higher for models where the common-envelope ejection is treated using the α-mechanism (energy conservation) than when using the γ-mechanism (angular-momentum conservation). We have estimated the total number of detectable DNS GW signals from the Galaxy by combining contributions from thin disc, thick disc, bulge and halo. The most probable numbers for an eLISA-type experiment are 0-1600 signals per year at S/N ≥ 1, 0-900 signals per year at S/N ≥ 3, and 0-570 at S/N ≥ 5, coming from about 0-65, 0-60 and 0-50 resolved DNS, respectively.

  14. Most Double Degenerate Low-mass White Dwarf Binaries Merge

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.; Kilic, Mukremin; Kenyon, Scott J.; Gianninas, A.

    2016-06-01

    We estimate the merger rate of double degenerate binaries containing extremely low mass (ELM; \\lt 0.3 M ⊙) white dwarfs (WDs) in the Galaxy. Such WDs are detectable for timescales of 0.1–1 Gyr in the ELM Survey; the binaries they reside in have gravitational wave merger times of 0.001–100 Gyr. To explain the observed distribution requires that most ELM WD binary progenitors detach from the common envelope phase with <1 hr orbital periods. We calculate the local space density of ELM WD binaries and estimate a merger rate of 3 × 10‑3 yr‑1 over the entire disk of the Milky Way; the merger rate in the halo is 10 times smaller. The ELM WD binary merger rate exceeds by a factor of 40 the formation rate of stable mass transfer AM CVn binaries, marginally exceeds the rate of underluminous supernovae, and is identical to the formation rate of R CrB stars. On this basis, we conclude that ELM WD binaries can be the progenitors of all observed AM CVn and possibly underluminous supernovae; however, the majority of He+CO WD binaries go through unstable mass transfer and merge, e.g., into single massive ∼1 M ⊙ WDs.

  15. DOUBLE COMPACT OBJECTS AS LOW-FREQUENCY GRAVITATIONAL WAVE SOURCES

    SciTech Connect

    Belczynski, Krzysztof; Bulik, Tomasz; Benacquista, Matthew

    2010-12-10

    We study the Galactic field population of double compact objects (DCOs; NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with the Laser Interferometer Space Antenna (LISA) at low gravitational wave frequencies. We calculate the Galactic numbers and physical properties of these binaries and show their relative contributions from the disk, bulge, and halo. Although the Galaxy hosts {approx}10{sup 5} DCO binaries emitting low-frequency gravitational waves, only a handful of these objects in the disk will be detectable with LISA, but none from the halo or bulge. This is because the bulk of these binaries are NS-NS systems with high eccentricities and long orbital periods (weeks/months) causing inefficient signal accumulation (a small number of signal bursts at periastron passage in one year of LISA observations) and rendering them undetectable in the majority of these cases. We adopt two evolutionary models that differ in their treatment of the common envelope (CE) phase that is a major (and still mostly unknown) process in the formation of close DCOs. Depending on the evolutionary model adopted, our calculations indicate the likely detection of about four NS-NS binaries and two BH-BH systems (model A; likely survival of progenitors through CE) or only a couple of NS-NS binaries (model B; suppression of the DCO formation due to CE mergers).

  16. Merging binary stars and the magnetic white dwarfs

    NASA Astrophysics Data System (ADS)

    Briggs, Gordon P.; Ferrario, Lilia; Tout, Christopher A.; Wickramasinghe, Dayal T.; Hurley, Jarrod R.

    2015-02-01

    A magnetic dynamo driven by differential rotation generated when stars merge can explain strong fields in certain classes of magnetic stars, including the high field magnetic white dwarfs (HFMWDs). In their case the site of the differential rotation has been variously proposed to be within a common envelope, the massive hot outer regions of a merged degenerate core or an accretion disc formed by a tidally disrupted companion that is subsequently incorporated into a degenerate core. We synthesize a population of binary systems to investigate the stellar merging hypothesis for observed single HFMWDs. Our calculations provide mass distribution and the fractions of white dwarfs that merge during a common envelope phase or as double degenerate systems in a post-common-envelope phase. We vary the common envelope efficiency parameter α and compare with observations. We find that this hypothesis can explain both the observed incidence of magnetism and the mass distribution of HFMWDs for a wide range of α. In this model, the majority of the HFMWDs are of the carbon-oxygen type and merge within a common envelope. Less than about a quarter of a per cent of HFMWDs originate from double degenerate stars that merge after common envelope evolution and these populate the high-mass tail of the HFMWD mass distribution.

  17. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  18. Post clamp

    NASA Technical Reports Server (NTRS)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  19. Double screening

    NASA Astrophysics Data System (ADS)

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-01

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  20. The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428.

    PubMed

    Santander-García, M; Rodríguez-Gil, P; Corradi, R L M; Jones, D; Miszalski, B; Boffin, H M J; Rubio-Díez, M M; Kotze, M M

    2015-03-01

    The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (M(⊙)). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche lobe as the star expands during the asymptotic giant branch phase. The excess gas eventually forms a common envelope surrounding both stars. Drag forces then result in the envelope being ejected into a bipolar planetary nebula whose equator is coincident with the orbital plane of the system. Systems in which both stars have ejected their envelopes and are evolving towards the white dwarf stage are said to be double degenerate. Here we report that Henize 2-428 has a double-degenerate core with a combined mass of ∼1.76M(⊙), which is above the Chandrasekhar limit (the maximum mass of a stable white dwarf) of 1.4M(⊙). This, together with its short orbital period (4.2 hours), suggests that the system should merge in 700 million years, triggering a type Ia supernova event. This supports the hypothesis of the double-degenerate, super-Chandrasekhar evolutionary pathway for the formation of type Ia supernovae. PMID:25686608

  1. Double White Dwarf Merger Rates

    NASA Astrophysics Data System (ADS)

    Toonen, Silvia; Nelemans, Gijs; Portegies Zwart, Simon

    2013-01-01

    Type Ia supernovae (SNe Ia) are very successfully used as standard candles on cosmological distance scales, but so far the nature of the progenitor(s) is unclear. A possible scenario for SNe Ia are merging carbon/oxygen white dwarfs with a combined mass exceeding the Chandrasekhar mass. We determine the theoretical rates and delay time distribution of these mergers for two different common envelope prescriptions and metallicities. The shape of the delay time distributions is rather insensitive to the assumptions. The normalization is a factor ~3-13 too low compared to observations.

  2. Double field theory inspired cosmology

    SciTech Connect

    Wu, Houwen; Yang, Haitang E-mail: hyanga@scu.edu.cn

    2014-07-01

    Double field theory proposes a generalized spacetime action possessing manifest T-duality on the level of component fields. We calculate the cosmological solutions of double field theory with vanishing Kalb-Ramond field. It turns out that double field theory provides a more consistent way to construct cosmological solutions than the standard string cosmology. We construct solutions for vanishing and non-vanishing symmetry preserving dilaton potentials. The solutions assemble the pre- and post-big bang evolutions in one single line element. Our results show a smooth evolution from an anisotropic early stage to an isotropic phase without any special initial conditions in contrast to previous models. In addition, we demonstrate that the contraction of the dual space automatically leads to both an inflation phase and a decelerated expansion of the ordinary space during different evolution stages.

  3. The yellow hypergiant HR 5171 A: Resolving a massive interacting binary in the common envelope phase

    NASA Astrophysics Data System (ADS)

    Chesneau, O.; Meilland, A.; Chapellier, E.; Millour, F.; van Genderen, A. M.; Nazé, Y.; Smith, N.; Spang, A.; Smoker, J. V.; Dessart, L.; Kanaan, S.; Bendjoya, Ph.; Feast, M. W.; Groh, J. H.; Lobel, A.; Nardetto, N.; Otero, S.; Oudmaijer, R. D.; Tekola, A. G.; Whitelock, P. A.; Arcos, C.; Curé, M.; Vanzi, L.

    2014-03-01

    Context. Only a few stars are caught in the very brief and often crucial stages when they quickly traverse the Hertzsprung-Russell diagram, and none has yet been spatially resolved in the mass transfer phase. Aims: We initiated long-term optical interferometry monitoring of the diameters of massive and unstable yellow hypergiants (YHG) with the goal of detecting both the long-term evolution of their radius and shorter term formation of a possible pseudo-photosphere related to proposed large mass-loss events. Methods: We observed HR 5171 A with AMBER/VLTI. We also examined archival photometric data in the visual and near-IR spanning more than 60 years, as well as sparse spectroscopic data. Results: HR 5171 A exhibits a complex appearance. Our AMBER data reveal a surprisingly large star for a YHG R∗ = 1315 ± 260R⊙ (or ~6.1 AU) at the distance of 3.6 ± 0.5 kpc. The source is surrounded by an extended nebulosity, and these data also show a large level of asymmetry in the brightness distribution of the system, which we attribute to a newly discovered companion star located in front of the primary star. The companion's signature is also detected in the visual photometry, which indicates an orbital period of Porb = 1304 ± 6 d. Modeling the light curve with the NIGHTFALL program provides clear evidence that the system is a contact or possibly over-contact eclipsing binary. A total current system mass of 39+40-22 M⊙ and a high mass ratio q ≥ 10 is inferred for the system. Conclusions: The low-mass companion of HR 5171 A is very close to the primary star that is embedded within its dense wind. Tight constraints on the inclination and vsini of the primary are lacking, which prevents us from determining its influence precisely on the mass-loss phenomenon, but the system is probably experiencing a wind Roche-Lobe overflow. Depending on the amount of angular momentum that can be transferred to the stellar envelope, HR 5171 A may become a fast-rotating B[e]/luminous blue variable/Wolf-Rayet star. In any case, HR 5171 A highlights the possible importance of binaries for interpreting the unstable YHGs and for massive star evolution in general. Based on observations made with ESO telescopes at the La Silla/ Paranal Observatory under program ID 088.D-0129 and from Gemini/South Observatory under program GS-2011A-C-4.Appendices are available in electronic form at http://www.aanda.org

  4. DISCOVERY OF A BRIGHT, EXTREMELY LOW MASS WHITE DWARF IN A CLOSE DOUBLE DEGENERATE SYSTEM

    SciTech Connect

    Vennes, S.; Kawka, A.; Nemeth, P.; Thorstensen, J. R.; Skinner, J. N.; Pigulski, A.; Steslicki, M.; Kolaczkowski, Z.; Srodka, P.

    2011-08-10

    We report the discovery of a bright (V {approx} 13.7), extremely low mass white dwarf in a close double degenerate system. We originally selected GALEX J171708.5+675712 for spectroscopic follow-up among a group of white dwarf candidates in an ultraviolet-optical reduced proper-motion diagram. The new white dwarf has a mass of 0.18 M{sub sun} and is the primary component of a close double degenerate system (P = 0.246137 days, K{sub 1} = 288 km s{sup -1}) comprising a fainter white dwarf secondary with M{sub 2} {approx} 0.9 M{sub sun}. Light curves phased with the orbital ephemeris show evidence of relativistic beaming and weaker ellipsoidal variations. The light curves also reveal secondary eclipses (depth {approx}8 mmag) while the primary eclipses appear partially compensated by the secondary gravitational deflection and are below detection limits. Photospheric abundance measurements show a nearly solar composition of Si, Ca, and Fe (0.1-1 sun), while the normal kinematics suggest a relatively recent formation history. Close binary evolutionary scenarios suggest that extremely low mass white dwarfs form via a common-envelope phase and possible Roche lobe overflow.

  5. Double pituitary adenomas.

    PubMed

    Iacovazzo, D; Bianchi, A; Lugli, F; Milardi, D; Giampietro, A; Lucci-Cordisco, E; Doglietto, F; Lauriola, L; De Marinis, L

    2013-04-01

    Double pituitary adenomas represent up to 2.6 % of pituitary adenomas in large surgical series and up to 3.3 % of patients with Cushing's disease have been found to have double or multiple pituitary adenomas. We report the case of a 60-year-old male patient whose medical history began in 2002 with erectile dysfunction; hyperprolactinemia was found and MRI showed a 6-mm area of delayed enhancement in the lateral portion of the right pituitary lobe. Treatment with cabergoline was started with normalization of prolactin levels; the following MRI, performed in 2005 and 2008, showed shrinkage of the pituitary lesion. In 2005, the patient began to manifest weight gain, hypertension, and facial plethora, but no further evaluations were done. In January 2010, the patient came to our attention and underwent multiple tests that suggested Cushing's disease. A new MRI was negative. Bilateral inferior petrosal sinus sampling showed significant pituitary-to-peripheral ratio and, in May 2010, the patient underwent exploratory pituitary surgery with evidence of a 1-2-mm white-coloured midline area compatible with pituitary adenoma that was surgically removed. Post-operatively, the patient's clinical conditions improved with onset of secondary hypoadrenalism. The histologic examination confirmed a pituitary adenoma (immunostaining was found to be positive for ACTH and negative for prolactin). We report the case of an ACTH-producing microadenoma metachronous to a prolactin secreting microadenoma although not confirmed histologically, shrunk by medical treatment. A review of data in the literature regarding double or multiple pituitary adenomas has also been done. PMID:23325364

  6. Rehabilitation of endodontically treated teeth using the radiopaque fiber post.

    PubMed

    Brown, Philip L; Hicks, Norman L

    2003-04-01

    Metallic posts fall short of satisfying contemporary guidelines for ideal post/core rehabilitation. Along with technological improvements in adhesive resins, cements, and composite restoratives, the evolution of fiber-reinforced posts allows the rehabilitation of endodontically treated teeth with greater esthetics and virtually no predisposition to root fracture. At least one fiber post system now complies with all of the ideal post characteristics described in the endodontic text. This article describes the potential for displacement of metal posts by low-modulus fiber posts, the differences between them, and the development and placement of a radiopaque, translucent, double-tapered fiber post. PMID:12769029

  7. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  8. Double inflation

    SciTech Connect

    Silk, J.; Turner, M.S.

    1986-04-01

    The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The ..cap omega..-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig.

  9. The effects of pre- and post-exercise consumption of multi-ingredient performance supplements on cardiovascular health and body fat in trained men after six weeks of resistance training: a stratified, randomized, double-blind study

    PubMed Central

    2013-01-01

    Background The cardiovascular (CV) and metabolic health benefits or risks associated with consumption of multi-ingredient performance supplements (MIPS) in conjunction with periodized resistance training (RT) in resistance-trained men are unknown. This population is a major target audience for performance supplements, and therefore, the purpose of this study was to investigate the combined effect of RT and commercially available pre- and post-exercise performance supplements on CV health and body fat in resistance-trained men. Methods Twenty-four resistance-trained men completed six weeks (three times/week) of periodized RT while either ingesting SHOT 15-min pre-exercise and SYN immediately post-exercise (multi-ingredient performance supplement group: MIPS) or an isocaloric maltodextrin placebo 15-min pre-exercise and immediately post-exercise (Placebo group). Before and after six weeks of RT and supplementation, resting heart rate (HR), blood pressure (BP), total body fat, android fat, gynoid fat, fat-free mass (FFM) and fasting blood measures of glucose, lipids, nitrate/nitrite (NOx), cortisol and high sensitivity C-reactive protein (hs-CRP) were measured. Statistical analysis was conducted using a one-way ANOVA for baseline differences and a 2 × 2 (group × time) repeated measures ANOVA and Tukey post-hoc tests where appropriate. Significance was set at p < 0.05. Results There was no group × time interaction for HR, BP, blood glucose, lipids, NOx, hs-CRP, cortisol concentrations or body fat. However, there was a time effect where significant decreases in body fat (mean ± SD; MIPS: -1.2 ± 1.2%; Placebo: -0.9 ± 1.1%), android fat (MIPS: -1.8 ± 2.1%; Placebo: -1.6 ± 2.0%), and gynoid fat (MIPS: -1.3 ± 1.6%; Placebo: -1.0 ± 1.4%) for both groups were observed. FFM increased in both groups, and a group × time interaction was observed with MIPS increasing significantly more than the Placebo group (4.2% vs. 1

  10. Double core evolution and X-ray binaries

    NASA Technical Reports Server (NTRS)

    Taam, R. E.

    1979-01-01

    The evolution of a 16-solar mass star and a 1-solar mass neutron star is followed through the common-envelope binary phase. It is found that the encounter of the neutron star with a yellow giant leads to coalescence of the two cores, while encounter with a red giant leads to hydrodynamic expansion and probable ejection of the common envelope. Within the context of the two rotation laws (1) uniform rotation (investigated in the present study), and (2) uniform specific angular momentum (considered in an earlier study), the results are independent of the choice for the angular-momentum distribution in the common envelope. Implications of the results for the binary pulsar phase are discussed.

  11. Crystal chemistry of a Ba-dominant analogue of hydrodelhayelite and natural ion-exchange transformations in double- and triple-layer phyllosilicates in post-volcanic systems of the Eifel region, Germany

    NASA Astrophysics Data System (ADS)

    Zubkova, N. V.; Chukanov, N. V.; Pekov, I. V.; Turchkova, A. G.; Lykova, I. S.; Schüller, W.; Ternes, B.; Pushcharovsky, D. Yu.

    2016-03-01

    A Ba-dominant (Ba > K) analogue of hydrodelhayelite (BDAH) from Löhley (Eifel Mts., Rhineland-Palatinate, Germany) and Ba-enriched varieties of related double- and triple-layer phyllosilicates from Eifel are studied. The crystal structure of BDAH was solved by direct methods and refined to R = 0.0698 [1483 unique reflections with I > 2σ(I)]. It is orthorhombic, Pmmn, a = 23.9532(9), b = 7.0522(3), c = 6.6064(3) Å, V = 1115.97(8) Å3, Z = 2. The structure is based upon delhayelite-type double-layer tetrahedral blocks [(Al,Si)4Si12O34(OH,O)4] connected by chains of (Ca,Fe)-centered octahedra. Ba2+ and subordinate K+ occur at partially vacant sites in zeolitic channels within the tetrahedral blocks. The crystal-chemical formula of BDAH is: (Ba0.42K0.34□0.24)(Ca0.88Fe0.12)2(□0.90Mg0.10)2[Si6(Al0.5Si0.5)2O17(OH0.71O0.29)2]ṡ6H2O. The formation of BDAH and Ba-rich varieties of altered delhayelite/fivegite, günterblassite and hillesheimite is considered as a result of leaching of Na, Cl, F and, partially, K and Ca accompanied with hydration and the capture of Ba as a result of natural ion exchange. These minerals are structurally a "bridge" between single-layer phyllosilicates and zeolites having the open three-dimensional tetrahedral Al-Si-O frameworks.

  12. Quark-novae Occurring in Massive Binaries : A Universal Energy Source in Superluminous Supernovae with Double-peaked Light Curves

    NASA Astrophysics Data System (ADS)

    Ouyed, Rachid; Leahy, Denis; Koning, Nico

    2016-02-01

    A quark-nova (QN; the sudden transition from a neutron star into a quark star), which occurs in the second common envelope (CE) phase of a massive binary, gives excellent fits to superluminous, hydrogen-poor, supernovae (SLSNe) with double-peaked light curves, including DES13S2cmm, SN 2006oz, and LSQ14bdq (http://www.quarknova.ca/LCGallery.html). In our model, the H envelope of the less massive companion is ejected during the first CE phase, while the QN occurs deep inside the second, He-rich, CE phase after the CE has expanded in size to a radius of a few tens to a few thousands of solar radii; this yields the first peak in our model. The ensuing merging of the quark star with the CO core leads to black hole formation and accretion, explaining the second long-lasting peak. We study a sample of eight SLSNe Ic with double-humped light curves. Our model provides good fits to all of these, with a universal explosive energy of 2 × 1052 erg (which is the kinetic energy of the QN ejecta) for the first hump. The late-time emissions seen in iPTF13ehe and LSQ14bdq are fit with a shock interaction between the outgoing He-rich (i.e., second) CE and the previously ejected H-rich (i.e., first) CE.

  13. A double-double/double-single computation package

    SciTech Connect

    Bailey, David H.

    2004-12-01

    The DDFUNIDSFUN software permits a new or existing Fortran-90 program to utilize double-double precision (approx. 31 digits) or double-single precision (approx. 14 digits) arithmetic. Double-double precision is required by a rapidly expandirtg body of scientific computations in physics and mathematics, for which the conventional 64-bit IEEE computer arithmetic (about 16 decimal digit accuracy) is not sufficient. Double-single precision permits users of systems that do not have hardware 64-bit IEEE arithmetic (such as some game systems) to perform arithmetic at a precision nearly as high as that of systems that do. Both packages run significantly faster Than using multiple precision or arbitrary precision software for this purpose. The package includes an extensive set of low-level routines to perform high-precision arithmetic, including routines to calculate various algebraic and transcendental functions, such as square roots, sin, ccc, exp, log and others. In addition, the package includes high-level translation facilities, so that Fortran programs can utilize these facilities by making only a few changes to conventional Fortran programs. In most cases, the only changes that are required are to change the type statements of variables that one wishes to be treated as multiple precision, plus a few other minor changes. The DDFUN package is similar in functionality to the double-double part of the GD package, which was previously written at LBNL. However, the DDFUN package is written exclusively in Fortran-90, thus avoidIng difficulties that some users experience when using GD, which includes both Fortran-90 and C++ code.

  14. A double-double/double-single computation package

    Energy Science and Technology Software Center (ESTSC)

    2004-12-01

    The DDFUNIDSFUN software permits a new or existing Fortran-90 program to utilize double-double precision (approx. 31 digits) or double-single precision (approx. 14 digits) arithmetic. Double-double precision is required by a rapidly expandirtg body of scientific computations in physics and mathematics, for which the conventional 64-bit IEEE computer arithmetic (about 16 decimal digit accuracy) is not sufficient. Double-single precision permits users of systems that do not have hardware 64-bit IEEE arithmetic (such as some game systems)more » to perform arithmetic at a precision nearly as high as that of systems that do. Both packages run significantly faster Than using multiple precision or arbitrary precision software for this purpose. The package includes an extensive set of low-level routines to perform high-precision arithmetic, including routines to calculate various algebraic and transcendental functions, such as square roots, sin, ccc, exp, log and others. In addition, the package includes high-level translation facilities, so that Fortran programs can utilize these facilities by making only a few changes to conventional Fortran programs. In most cases, the only changes that are required are to change the type statements of variables that one wishes to be treated as multiple precision, plus a few other minor changes. The DDFUN package is similar in functionality to the double-double part of the GD package, which was previously written at LBNL. However, the DDFUN package is written exclusively in Fortran-90, thus avoidIng difficulties that some users experience when using GD, which includes both Fortran-90 and C++ code.« less

  15. Biological post

    PubMed Central

    Kumar, B. Suresh; Kumar, Senthil; Mohan Kumar, N. S.; Karunakaran, J. V.

    2015-01-01

    Anterior tooth fracture as a result of traumatic injuries, is frequently encountered in endodontic practice. Proper reconstruction of extensively damaged teeth can be achieved through the fragment reattachment procedure known as “biological restoration.” This case report refers to the esthetics and functional recovery of extensively damaged maxillary central incisor through the preparation and adhesive cementation of “biological post” in a young patient. Biological post obtained through extracted teeth from another individual–represent a low-cost option and alternative technique for the morphofunctional recovery of extensively damaged anterior teeth. PMID:26538952

  16. The Cambridge Double Star Atlas

    NASA Astrophysics Data System (ADS)

    MacEvoy, Bruce; Tirion, Wil

    2015-12-01

    Preface; What are double stars?; The binary orbit; Double star dynamics; Stellar mass and the binary life cycle; The double star population; Detecting double stars; Double star catalogs; Telescope optics; Preparing to observe; Helpful accessories; Viewing challenges; Next steps; Appendices: target list; Useful formulas; Double star orbits; Double star catalogs; The Greek alphabet.

  17. Double outlet right ventricle

    MedlinePlus

    ... medlineplus.gov/ency/article/007328.htm Double outlet right ventricle To use the sharing features on this page, please enable JavaScript. Double outlet right ventricle (DORV) is a heart disease that is ...

  18. Study protocol for a pilot, randomised, double-blinded, placebo controlled trial of perineural local anaesthetics and steroids for chronic post-traumatic neuropathic pain in the ankle and foot: the PREPLANS study

    PubMed Central

    Bhatia, Anuj; Bril, Vera; Brull, Richard T; Perruccio, Anthony; Wijeysundera, Duminda; Alvi, Sabbeh; Lau, Johnny; Gandhi, Rajiv; Mahomed, Nizar; Davis, Aileen M

    2016-01-01

    Introduction Peripheral neuropathic pain (PNP) associated with trauma is often refractory to treatment. Administration of local anaesthetics (LA) and steroids around injured nerves has been proposed as an option for patients unresponsive to conventional treatments for refractory PNP following trauma. There is insufficient evidence to support a large, potentially expensive, full-scale randomised controlled trial (RCT) that involves comparison of effects of perineural steroids and LA against LA or saline injections on analgesia, physical and psychological functioning, and quality of life. There is also a lack of data that would allow estimation of analgesic efficacy or sample size for the full-scale RCT. The objective of this pilot RCT is to yield information to support planning of a full-scale RCT in this population. Methods and Analysis 30 participants with post-traumatic PNP in the ankle and foot of moderate-to-severe intensity and duration of more than 3 months will be enrolled in this pilot RCT. Participants will be randomised to receive three ultrasound-guided perineural injections of 0.9% saline, 0.25% bupivacaine (a long-acting LA) or a combination of 0.25% bupivacaine and a steroid (methylprednisolone 16 mg per nerve) at weekly intervals. The primary objectives are to determine the feasibility and sample size of a full-scale RCT in this population. The secondary objectives are to evaluate the effect of study interventions on analgesia, persistence of neuropathic pain, psychological and physical function, quality of life and participants' global impression of change at 1 and 3 months after the interventions. In addition, adverse effects associated with perineural injections and with systemic absorption of steroids will also be recorded. Ethics and Dissemination The protocol was approved by the University Health Network Research Ethics Board (UHN REB number 15-9584-A). The results will be disseminated in peer-reviewed journals and at scientific

  19. Chromosome doubling method

    DOEpatents

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  20. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  1. Post-Lyme disease syndrome

    PubMed Central

    Dąbek, Józefa; Cieślik, Paweł

    2015-01-01

    About 10% of patients with Lyme disease continue to experience musculoskeletal pain and cognitive dysfunction after recommended antibiotic treatment. This condition is called post-Lyme disease syndrome (PLDS) or post-treatment Lyme disease syndrome. These two terms are used interchangeably. The pathogenesis of PLDS has been controversial. The hypothesis that patients with PLDS may harbor hidden reservoirs of Borrelia burgdorferi after their initial antibiotic treatment is difficult to accept. The prospective, double-blind studies contradict this point of view. Also, recently published research applying xenodiagnosis to PLDS supports the opinion that PLDS most likely has an autoimmune background. Lengthy courses of antibiotics are not justified in patients with PLDS because of the lack of benefit, and they are fraught with hazards. Most patients with PLDS recover from persistent symptoms with time. However, it can take months before they feel completely well.

  2. Topological Quantum Double

    NASA Astrophysics Data System (ADS)

    Bonneau, Philippe

    Following a preceding paper showing how the introduction of a t.v.s. topology on quantum groups led to a remarkable unification and rigidification of the different definitions, we adapt here, in the same way, the definition of quantum double. This topological double is dualizable and reflexive (even for infinite dimensional algebras). In a simple case we show, considering the double as the "zero class" of an extension theory, the uniqueness of the double structure as a quasi-Hopf algebra. A la suite d'un précédent article montrant comment l'introduction d'une topologie d'e.v.t. sur les groupes quantiques permet une unification et une rigidification remarquables des différentes définitions, on adapte ici de la même manière la définition du double quantique. Ce double topologique est alors dualisable et reflexif (même pour des algèbres de dimension infinie). Dans un cas simple on montre, en considérant le double comme la "classe zéro" d'une théorie d'extensions, l'unicité de cette structure comme algèbre quasi-Hopf.

  3. Emerging double helical nanostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-07-01

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on `bottom-up' and `top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  4. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  5. Double aortic arch

    MedlinePlus

    ... double aortic arch may press on the windpipe (trachea) and esophagus, leading to trouble breathing and swallowing. ... to relieve pressure on the esophagus and windpipe (trachea). The surgeon ties off the smaller branch and ...

  6. PG 0308 + 096 and PG 1026 + 002 - Two new short period binary stars resulting from common-envelope evolution

    NASA Technical Reports Server (NTRS)

    Saffer, Rex A.; Wade, Richard A.; Liebert, James; Green, Richard F.; Sion, Edward M.; Bechtold, J.; Foss, Diana; Kidder, K.

    1993-01-01

    Ultraviolet spectroscopy, optical spectroscopy, and spectrophotometry have been used to study the excess UV stars PG 0308 + 096 and PG 1026 + 002. Both objects are short-period binary systems, each containing a DA white dwarf star and a dM star. Orbital periods of approximately 0.284 day for PG 0308 + 096, and aproximately 0.597 day for PG 1026, have been found by spectroscopic analysis of the H-alpha emission line. Ly-alpha and Balmer line profile fitting were used to estimate the mass of white dwarf stars; mass estimates for the dM stars are based on their spectral types. The orbital inclinations are derived from these masses, the periods, and amplitudes of the H-alpha radial velocity curves. The equivalent width of the H-alpha emission line, in each binary system, varies with the orbital phase in such a manner as to imply that it arises, in large part at least, from the hemisphere of the M star that faces the white dwarf star.

  7. A COMPREHENSIVE STUDY OF CLOSE DOUBLE WHITE DWARFS AS GRAVITATIONAL WAVE SOURCES: EVOLUTIONARY CHANNELS, BIRTH RATES, AND PHYSICAL PROPERTIES

    SciTech Connect

    Liu Jinzhong; Han Zhanwen; Zhang Fenghui; Zhang Yu

    2010-08-20

    Close double white dwarfs (CDWDs) are believed to dominate the Galactic gravitational wave (GW) radiation in the frequency range 10{sup -4} to 0.1 Hz, which will be detected by the Laser Interferometer Space Antenna (LISA) detector. The aim of this detector is to detect GW radiation from astrophysical sources in the universe and to help improve our understanding of the origin of the sources and their physical properties (masses and orbital periods). In this paper, we study the probable candidate sources in the Galaxy for the LISA detector: CDWDs. We use the binary population synthesis approach of CDWDs together with the latest findings of the synthesis models from Han, who proposed three evolutionary channels: (1) stable Roche lobe overflow plus common envelope (RLOF+CE), (2) CE+CE, and (3) exposed core plus CE. As a result, we systematically investigate the detailed physical properties (the distributions of masses, orbital periods, and chirp masses) of the CDWD sources for the LISA detector, examine the importance of the three evolutionary channels for the formation of CDWDs, and carry out Monte Carlo simulations. Our results show that RLOF+CE and CE+CE are the main evolutionary scenarios leading to the formation of CDWDs. For the LISA detectable sources, we also explore and discuss the importance of these three evolutionary channels. Using the calculated birth rate, we compare our results to the LISA sensitivity curve and the foreground noise floor of CDWDs. We find that our estimate for the number of CDWD sources that can be detected by the LISA detector is greater than 10,000. We also find that the detectable CDWDs are produced via the CE+CE channel and we analyze the fraction of the detectable CDWDs that are double helium (He+He), or carbon-oxygen plus helium (CO+He) WD binary systems.

  8. Dynamics of Double Stochastic Operators

    NASA Astrophysics Data System (ADS)

    Saburov, Mansoor

    2016-03-01

    A double stochastic operator is a generalization of a double stochastic matrix. In this paper, we study the dynamics of double stochastic operators. We give a criterion for a regularity of a double stochastic operator in terms of absences of its periodic points. We provide some examples to insure that, in general, a trajectory of a double stochastic operator may converge to any interior point of the simplex.

  9. Double Emulsion Templated Celloidosomes

    NASA Astrophysics Data System (ADS)

    Arriaga, Laura R.; Marquez, Samantha M.; Kim, Shin-Hyun; Chang, Connie; Wilking, Jim; Monroy, Francisco; Marquez, Manuel; Weitz, David A.

    2012-02-01

    We present a novel approach for fabricating celloidosomes, which represent a hollow and spherical three-dimensional self-assembly of living cells encapsulating an aqueous core. Glass- capillary microfluidics is used to generate monodisperse water-in-oil-in-water double emulsion templates using lipids as stabilizers. Such templates allow for obtaining single but also double concentric celloidosomes. In addition, after a solvent removal step the double emulsion templates turn into monodisperse lipid vesicles, whose membrane spontaneously phase separates when choosing the adequate lipid composition, providing the adequate scaffold for fabricating Janus-celloidosomes. These structures may find applications in the development of bioreactors in which the synergistic effects of two different types of cells selectively adsorbed on one of the vesicle hemispheres may be exploited.

  10. Tracking The Double Eagle

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Last summer a trio of aeronauts made aviation history. Ben Abruzzo, Maxie Anderson and Larry Newman, all of Albuquerque, New Mexico, piloted their balloon Double Eagle I1 from Presque Isle, Maine to Miserey, France, some 50 miles from Paris. They were the first to negotiate a successful Atlantic crossing in a freeflying balloon after a score of attempts over a span of more than a century. A year earlier, Abruzzo and Anderson had made an unsuccessful try in their predecessor balloon Double Eagle. On that occasion, a NASA-developed satellite beacon helped save their lives. Carried aboard the balloon, the simple, seven-pound beacon continuously transmitted signals to NASA's Nimbus-6 satellite. Nimbus relayed the signals to monitors at Goddard Space Flight Center, enabling Goddard to compute the balloon's position. Position reports were then telephoned regularly to Double Eagle's control center at Bedford, Massachusetts. This monitoring system proved invaluable when the balloon encountered trouble several days after liftoff.

  11. Double face sealing device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1991-01-01

    A double face sealing device for mounting between two surfaces to provide an airtight and fluid-tight seal between a closure member bearing one of the surfaces and a structure or housing bearing the other surface which extends around the opening or hatchway to be closed. The double face sealing device includes a plurality of sections or segments mounted to one of the surfaces, each having a main body portion, a pair of outwardly extending and diverging, cantilever, spring arms, and a pair of inwardly extending and diverging, cantilever, spring arms, an elastomeric cover on the distal, free, ends of the outwardly extending and diverging spring arms, and an elastomeric cover on the distal, free, ends of the inwardly extending and diverging spring arms. The double face sealing device has application or use in all environments requiring a seal, but is particularly useful to seal openings or hatchways between compartments of spacecraft or aircraft.

  12. Design friendly double patterning

    NASA Astrophysics Data System (ADS)

    Yesilada, Emek

    2012-03-01

    Double patterning using 193nm immersion has been adapted as the solution to enable 2x nm technology nodes until the arrival of EUV tools. As a result the past few years have seen a huge effort in creating double patterning friendly design flows. These flows have so far proposed a combination of decomposition rules at cell level and/or at placement level as well as sophisticated decomposition tools with varying density, design iteration and decomposition complexity penalties. What is more, designers have to familiarize themselves with double patterning challenges and decomposition tools. In this paper an alternative approach is presented that allows the development of dense standard cells with minimal impact on design flow due to double patterning. A real case study is done on 20nm node first metal layer where standard cells are designed without considering decomposition restrictions. The resulting layout is carefully studied in order to establish decomposition or color rules that can map the layout into two masks required for double patterning but without the need of complex coloring algorithms. Since the rules are derived from a decomposition unaware design they do not in return impose heavy restrictions on the design at the cell or placement level and show substantial density gains compared to previously proposed methods. Other key advantages are a simplified design flow without complex decomposition tools that can generate a faster time to market solution all at the same time keeping designers isolated from the challenges of the double patterning. The derived design rules highlight process development path required for design driven manufacturing.

  13. Double Bragg Interferometry.

    PubMed

    Ahlers, H; Müntinga, H; Wenzlawski, A; Krutzik, M; Tackmann, G; Abend, S; Gaaloul, N; Giese, E; Roura, A; Kuhl, R; Lämmerzahl, C; Peters, A; Windpassinger, P; Sengstock, K; Schleich, W P; Ertmer, W; Rasel, E M

    2016-04-29

    We employ light-induced double Bragg diffraction of delta-kick collimated Bose-Einstein condensates to create three symmetric Mach-Zehnder interferometers. They rely on (i) first-order, (ii) two successive first-order, and (iii) second-order processes which demonstrate the scalability of the corresponding momentum transfer. With respect to devices based on conventional Bragg scattering, these symmetric interferometers double the scale factor and feature a better suppression of noise and systematic uncertainties intrinsic to the diffraction process. Moreover, we utilize these interferometers as tiltmeters for monitoring their inclination with respect to gravity. PMID:27176520

  14. Double Bragg Interferometry

    NASA Astrophysics Data System (ADS)

    Ahlers, H.; Müntinga, H.; Wenzlawski, A.; Krutzik, M.; Tackmann, G.; Abend, S.; Gaaloul, N.; Giese, E.; Roura, A.; Kuhl, R.; Lämmerzahl, C.; Peters, A.; Windpassinger, P.; Sengstock, K.; Schleich, W. P.; Ertmer, W.; Rasel, E. M.

    2016-04-01

    We employ light-induced double Bragg diffraction of delta-kick collimated Bose-Einstein condensates to create three symmetric Mach-Zehnder interferometers. They rely on (i) first-order, (ii) two successive first-order, and (iii) second-order processes which demonstrate the scalability of the corresponding momentum transfer. With respect to devices based on conventional Bragg scattering, these symmetric interferometers double the scale factor and feature a better suppression of noise and systematic uncertainties intrinsic to the diffraction process. Moreover, we utilize these interferometers as tiltmeters for monitoring their inclination with respect to gravity.

  15. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  16. Post-Adolescent Issues

    MedlinePlus

    Search COPING & HEALING CARING FOR A CHILD: POST-ADOLESCENT ISSUES As your child reaches adulthood, there will ... intake. New issues that you and your post adolescent child may want to discus together with his/ ...

  17. Double-Glazing Interferometry

    ERIC Educational Resources Information Center

    Toal, Vincent; Mihaylova, Emilia M.

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for…

  18. Rosette (Double Blossom)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rosette, or double blossom, is a serious disease of erect blackberries that is limited to the genus Rubus. Rosette may occur on trailing blackberries and dewberries, but rarely on red and black raspberries. In the United States, rosette occurs from New Jersey to Illinois and southwest to Texas and i...

  19. Double layers without current

    SciTech Connect

    Perkins, F.W.; Sun, Y.C.

    1980-11-01

    The steady-state solution of the nonlinear Vlasov-Poisson equations is reduced to a nonlinear eigenvalue problem for the case of double-layer (potential drop) boundary conditions. Solutions with no relative electron-ion drifts are found. The kinetic stability is discussed. Suggestions for creating these states in experiments and computer simulations are offered.

  20. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, Dale R.

    1984-01-01

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  1. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, D.R.

    1982-09-23

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  2. Double Trouble (Abstract)

    NASA Astrophysics Data System (ADS)

    Simonsen, M.

    2015-12-01

    (Abstract only) Variable stars with close companions can be difficult to accurately measure and characterize. The companions can create misidentifications, which in turn can affect the perceived magnitudes, amplitudes, periods, and colors of the variable stars. We will show examples of these Double Trouble stars and the impact their close companions have had on our understanding of some of these variable stars.

  3. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the institution's…

  4. Sun Packs Double Punch

    NASA Video Gallery

    On August 3, the sun packed a double punch, emitting a M6.0-class flare at 9:43 am EDT. This video is of the second, slightly stronger M9.3-class flare at 11:41 pm EDT. Both flares had significant ...

  5. Double-Entry Bookkeeping.

    ERIC Educational Resources Information Center

    Snyder, Herbert

    1999-01-01

    Explains the principles and mechanics of double-entry bookkeeping as a part of the accounting cycle to produce a functioning set of accounting records. Suggests that libraries need to have accurate and timely information about their spending to gain financial control and protect against fraud and abuse. (LRW)

  6. A matterless double slit

    NASA Astrophysics Data System (ADS)

    King, Ben; di Piazza, Antonino; Keitel, Christoph H.

    2010-02-01

    Double slits provide incoming particles with a choice. Those that survive passage through the slits have chosen from two possible paths, which interfere to distribute them in a wave-like manner. Such wave-particle duality continues to be challenged and investigated in a broad range of disciplines with electrons, neutrons, helium atoms, C60 fullerenes, Bose-Einstein condensates and biological molecules. All variants have hitherto involved material constituents. We present a matterless double-slit scenario in which photons generated from virtual electron-positron pair annihilation in head-on collisions of a probe laser field with two ultra-intense laser beams form a double-slit interference pattern. Such electromagnetic fields are predicted to induce material-like behaviour in vacuum, supporting elastic scattering between photons. Our double-slit scenario presents, on the one hand, a realizable method with which to observe photon-photon scattering and, on the other hand, demonstrates the possibility of both controlling light with light and non-locally investigating features of the quantum vacuum structure.

  7. Double Marking Revisited

    ERIC Educational Resources Information Center

    Brooks, Val

    2004-01-01

    In 2002, the Qualifications and Curriculum Authority (QCA) published the report of an independent panel of experts into maintaining standards at Advanced Level (A-Level). One of its recommendations was for: limited experimental double marking of scripts in subjects such as English to determine whether the strategy would significantly reduce errors…

  8. [Double ricochet marks].

    PubMed

    Sellier, K

    1987-01-01

    When bullets are flying stably and ricochet on a surface, only one mark is produced. In contrast yawing bullets can produce a double mark if the angle of incidence is sufficiently small (less than or equal to 5 degrees). Distances up to 15 cm were seen between the two marks. PMID:3660953

  9. Teaching the Double Layer.

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1983-01-01

    Suggests various methods for teaching the double layer in electrochemistry courses. Topics addressed include measuring change in absolute potential difference (PD) at interphase, conventional electrode potential scale, analyzing absolute PD, metal-metal and overlap electron PDs, accumulation of material at interphase, thermodynamics of electrified…

  10. Double Degrees: Double the Trouble or Twice the Return?

    ERIC Educational Resources Information Center

    Russell, A. Wendy; Dolnicar, Sara; Ayoub, Marina

    2008-01-01

    Double degrees (also called joint or combined degrees)--programs of study combining two bachelor degrees--are increasingly popular in Australian universities, particularly among women. A case study using qualitative and quantitative surveys of current and past double degree students is presented. The study indicates that double degrees benefit…

  11. Tests on Double Layer Metalization

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1983-01-01

    28 page report describes experiments in fabrication of integrated circuits with double-layer metalization. Double-layer metalization requires much less silicon "real estate" and allows more flexibility in placement of circuit elements than does single-layer metalization.

  12. Measuring the Double Helix

    SciTech Connect

    Mathew-Fenn, R.S.; Das, R.; Harbury, P.A.B.

    2009-05-26

    DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.

  13. Double meningocele. Case report.

    PubMed

    Durmaz, R; Arslantaş, A; Ozön, Y H; Tel, E

    2000-01-01

    The coexistence of two distinct meningoceles of the spine is a very unusual event. We report a three-day-old boy with double meningoceles at the thoracic and lumbar levels. The connection between the stalk of the thoracic meningocele and the spinal cord, as seen on magnetic resonance imaging, showed a neurological involvement in this lesion. Our case is only the third without association of congenital anomalies or neurofibromatosis to be reported to date. PMID:11196754

  14. The double massa intermedia

    PubMed Central

    Baydin, Serhat; Gungor, Abuzer; Baran, Oguz; Tanriover, Necmettin; Rhoton, Albert L.

    2016-01-01

    Background: To describe the rare finding of a double massa intermedia (MI). Typically, the MI (interthalamic adhesion) is a single bridge of gray matter connecting the medial surfaces of the thalami. Methods: Twelve formalin- and alcohol-fixed human third ventricles were examined from superior to inferior by fiber dissection technique under ×6 to ×40 magnifications and with the endoscope. Results: In all hemispheres, the anterior and posterior commissure were defined. The MI, which bridges the medial surfaces of the thalami, was defined in all hemispheres. In one hemisphere, there was a second bridge between the thalami, located posteroinferior to the common MI. Endoscopic view confirmed that there was a second MI in this specimen. The MI usually traverses the third ventricle posterior to the foramen of Monro and connects the paired thalami. The MI is an important landmark during endoscopic and microscopic surgeries of the third ventricle. Although a double MI is very rare, surgeons should be aware of the possibility in their surgical planning. Conclusion: The surgeon should be aware of the possibility of a double MI to avoid confusion during third ventricle surgery. PMID:27127695

  15. Double face sealing device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1991-01-01

    A double face sealing device is disclosed for mounting between two surfaces to provide an air-tight and fluid-tight seal between a closure member bearing one of the surfaces and a structure or housing bearing the other surface which extends around the opening or hatchway to be closed. The double face sealing device includes a plurality of sections or segments mounted to one of the surfaces, each having a main body portion, a pair of outwardly extending and diverging, cantilever, spring arms, and a pair of inwardly extending and diverging, cantilever, spring arms, an elastomeric cover on the distal, free ends of the outwardly extending and diverging spring arms, and an elastomeric cover on the distal, free, ends of the outwardly extending and diverging spring arms, and an elastomeric cover on the distal, free ends of the inwardly extending and diverging spring arms. The double face sealing device has application or use in all environments requiring a seal, but is particularly useful to seal openings or hatchways between compartments of spacecraft or aircraft.

  16. Colloidal Double Quantum Dots

    PubMed Central

    2016-01-01

    Conspectus Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole–dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single

  17. Colloidal Double Quantum Dots.

    PubMed

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  18. English in Political Discourse of Post-Suharto Indonesia.

    ERIC Educational Resources Information Center

    Bernsten, Suzanne

    This paper illustrates increases in the use of English in political speeches in post-Suharto Indonesia by analyzing the phonological, morphological, and syntactic assimilation of loanwords (linguistic borrowing), as well as hybridization and code switching, and phenomena such as doubling and loan translations. The paper also examines the mixed…

  19. 6. CONNECTION OF END POST AND TOP CHORD (TWO CHANNELS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. CONNECTION OF END POST AND TOP CHORD (TWO CHANNELS CONNECTED WITH COVER PLATES AND LACING BARS) WITH DIAGONALS (LOOP WELDED DOUBLE RECTILINEAR EYE BARS). - Daphna Creek Pratt Truss Bridge, State Route 1414, Holly Hill Street, Spanning Dahna Creek, Broadway, Rockingham County, VA

  20. The Double Star mission

    NASA Astrophysics Data System (ADS)

    Liu, Z. X.; Escoubet, C. P.; Pu, Z.; Laakso, H.; Shi, J. K.; Shen, C.; Hapgood, M.

    2005-11-01

    The Double Star Programme (DSP) was first proposed by China in March, 1997 at the Fragrant Hill Workshop on Space Science, Beijing, organized by the Chinese Academy of Science. It is the first mission in collaboration between China and ESA. The mission is made of two spacecraft to investigate the magnetospheric global processes and their response to the interplanetary disturbances in conjunction with the Cluster mission. The first spacecraft, TC-1 (Tan Ce means "Explorer"), was launched on 29 December 2003, and the second one, TC-2, on 25 July 2004 on board two Chinese Long March 2C rockets. TC-1 was injected in an equatorial orbit of 570x79000 km altitude with a 28° inclination and TC-2 in a polar orbit of 560x38000 km altitude. The orbits have been designed to complement the Cluster mission by maximizing the time when both Cluster and Double Star are in the same scientific regions. The two missions allow simultaneous observations of the Earth magnetosphere from six points in space. To facilitate the comparison of data, half of the Double Star payload is made of spare or duplicates of the Cluster instruments; the other half is made of Chinese instruments. The science operations are coordinated by the Chinese DSP Scientific Operations Centre (DSOC) in Beijing and the European Payload Operations Service (EPOS) at RAL, UK. The spacecraft and ground segment operations are performed by the DSP Operations and Management Centre (DOMC) and DSOC in China, using three ground station, in Beijing, Shanghai and Villafranca.

  1. Quark-Novae in massive binaries: a model for double-humped, hydrogen-poor, superluminous Supernovae

    NASA Astrophysics Data System (ADS)

    Ouyed, Rachid; Leahy, Denis; Koning, Nico

    2015-12-01

    LSQ14bdq and SN 2006oz are superluminous, hydrogen-poor, SNe with double-humped light curves. We show that a Quark-Nova (QN; explosive transition of the Neutron Star - NS - to a quark star -QS) occurring in a massive binary, experiencing two Common Envelope (CE) phases, can quantitatively explain the light curves of LSQ14bdq and SN 2006oz. The more massive component (A) explodes first as a normal SN, yielding a NS which ejects the hydrogen envelope of the companion when the system enters its first CE phase. During the second CE phase, the NS spirals into and inflates the second He-rich CE. In the process it gains mass and triggers a QN, outside of the CO core, leaving behind a QS. The first hump in our model is the QN shock re-energizing the expanded He-rich CE. The QN occurs when the He-rich envelope is near maximum size (˜1000 R⊙) and imparts enough energy to unbind and eject the envelope. Subsequent merging of the QS with the CO core of component B, driven by gravitational radiation, turns the QS to a black hole. The ensuing black hole accretion provides sufficient power for the second brighter and long lasting hump. Our model suggests a possible connection between SLSNe-I and type Ic-BL SNe which occur when the QN is triggered inside the CO core. We estimate the rate of QNe in massive binaries during the second CE phase to be ˜5 × 10-5 of that of core-collapse SNe.

  2. The Double Chooz Experiment

    NASA Astrophysics Data System (ADS)

    Pfahler, Patrick; Double Chooz Collaboration

    2012-07-01

    Double Chooz is a reactor bar nue-disappearance experiment situated at the commercial nuclear power plant of Chooz in northern France. The experiment aims for the revelation of the last unknown mixing angle Θ13 as a part of the neutrino mixing matrix or the improvement of the upper limit for sin2(2Θ13), which is currently < 0.14 (90% CL). A newly developed gadolinium-loaded liquid scintillator as target allows the detection of electron-anti-neutrinos (bar nue) using the inverse beta decay and its distinct decay pattern (bar nue + p → e+ +n). Double Chooz uses two identical detectors at different distances in order to reduce systematic uncertainties. This will allow, after a data taking phase of 4 years, an improvement on sin2(2Θ13) down to < 0.03 (90% CL). The first (far) detector has successfully been installed and filled, and takes data since April of 2011. A preliminary analysis of first 120 days revealed about 4000 Neutrino-candidates and a stable detector-setup with low backgrounds. The commissioning of the second (near) detector is expected for the beginning of 2013 and will provide maximum sensitivity for the experiment.

  3. Double core evolution. 7: The infall of a neutron star through the envelope of its massive star companion

    NASA Technical Reports Server (NTRS)

    Terman, James L.; Taam, Ronald E.; Hernquist, Lars

    1995-01-01

    Binary systems with properties similar to those of high-mass X-ray binaries are evolved through the common envelope phase. Three-dimensional simulations show that the timescale of the infall phase of the neutron star depends upon the evolutionary state of its massive companion. We find that tidal torques more effectively accelerate common envelope evolution for companions in their late core helium-burning stage and that the infall phase is rapid (approximately several initial orbital periods). For less evolved companions the decay of the orbit is longer; however, once the neutron star is deeply embedded within the companion's envelope the timescale for orbital decay decreases rapidly. As the neutron star encounters the high-density region surrounding the helium core of its massive companion, the rate of energy loss from the orbit increases dramatically leading to either partial or nearly total envelope ejection. The outcome of the common envelope phase depends upon the structure of the evolved companion. In particular, it is found that the entire common envelope can be ejected by the interaction of the neutron star with a red supergiant companion in binaries with orbital periods similar to those of long-period Be X-ray binaries. For orbital periods greater than or approximately equal to 0.8-2 yr (for companions of mass 12-24 solar mass) it is likely that a binary will survive the common envelope phase. For these systems, the structure of the progenitor star is characterized by a steep density gradient above the helium core, and the common envelope phase ends with a spin up of the envelope to within 50%-60% of corotation and with a slow mass outflow. The efficiency of mass ejection is found to be approximately 30%-40%. For less evolved companions, there is insufficient energy in the orbit to unbind the common envelope and only a fraction of it is ejected. Since the timescale for orbital decay is always shorter than the mass-loss timescale from the common envelope

  4. Double layers and electrostatic shocks

    NASA Technical Reports Server (NTRS)

    Hershkowitz, N.

    1981-01-01

    It is shown that it is useful to define double layers and shocks so that the ion phase spaces of double layers are the mirror image (about zero ion velocity) of the ion phase spaces for laminar electrostatic shocks. The distinguishing feature is the direction of the free ion velocity. It is also shown that double layers can exist without the presence of trapped ions. The Bohm condition for double layers, that the ion drift velocity on the high potential side must be greater than the ion sound velocity, is shown to be related to a requirement of a lower limit on the Mach number of laminar electrostatic shocks

  5. Colored Flag by Double Refraction.

    ERIC Educational Resources Information Center

    Reid, Bill

    1994-01-01

    Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

  6. Apple Valley Double Star Workshop

    NASA Astrophysics Data System (ADS)

    Brewer, Mark

    2015-05-01

    The High Desert Astronomical Society hosts an annual double star workshop, where participants measure the position angles and separations of double stars. Following the New Generation Science Standards (NGSS), adopted by the California State Board of Education, participants are assigned to teams where they learn the process of telescope set-up and operation, the gathering of data, and the reduction of the data. Team results are compared to the latest epoch listed in the Washington Double Star Catalog (WDS) and papers are written for publication in the Journal of Double Star Observations (JDSO). Each team presents a PowerPoint presentation to their peers about actual hands-on astronomical research.

  7. Strain balanced quantum posts

    SciTech Connect

    Alonso-Alvarez, D.; Alen, B.; Ripalda, J. M.; Llorens, J. M.; Taboada, A. G.; Briones, F.; Roldan, M. A.; Hernandez-Saz, J.; Hernandez-Maldonado, D.; Herrera, M.; Molina, S. I.

    2011-04-25

    Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here, we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.

  8. Dual double field theory

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric A.; Hohm, Olaf; Penas, Victor A.; Riccioni, Fabio

    2016-06-01

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O( D, D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O( D, D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for "exotic" dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  9. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Cremonesi, Oliviero

    2016-05-01

    After more than 3/4 of century from its proposal, Neutrinoless Double Beta Decay (NLDBD) is still missing observation and continues to represent the only practical method for investigating the Dirac/Majorana nature of neutrinos. In case neutrinos would be Majorana particles, NLDBD would provide unique informations on their properties (absolute mass scale and Majorana phases). Boosted by the discovery of neutrino oscillations, a number of experiments with improved sensitivity have been proposed in the past decade. Some of them have recently started operation and others are ready to start. They will push the experimental sensitivity on the decay halflife beyond 1026 year, starting to analyze the region of the inverted mass hierarchy. The status and perspectives of the ongoing experimental effort are reviewed. Uncertainties coming from the calculation othe decay nuclear matrix elements (NME) as well as the recently suggested possibility of a relevant quenching of the axial coupling constant are also discussed.

  10. Double layer secure sketch

    NASA Astrophysics Data System (ADS)

    Li, Cai

    2012-09-01

    Secure sketch has been applied successfully in a wide variety of applications like cryptography, biometric authentication systems and so on. All of these secure sketches have properties in common namely error-tolerance and small entropy loss. The former ensures an input set w' can unlock the system if w' is substantially overlapped with a template set w while the latter means it is hard for an adversary to get the information of w even with the knowledge of s, which is produced by w and stored in the system publicly. In their constructions, they all consider w as a set of atomic elements. However, in the real word, it is very likely the elements in the template set are sets as well. In this paper, we propose a double layer secure sketch to address this issue.

  11. Doubled Color Codes

    NASA Astrophysics Data System (ADS)

    Bravyi, Sergey

    Combining protection from noise and computational universality is one of the biggest challenges in the fault-tolerant quantum computing. Topological stabilizer codes such as the 2D surface code can tolerate a high level of noise but implementing logical gates, especially non-Clifford ones, requires a prohibitively large overhead due to the need of state distillation. In this talk I will describe a new family of 2D quantum error correcting codes that enable a transversal implementation of all logical gates required for the universal quantum computing. Transversal logical gates (TLG) are encoded operations that can be realized by applying some single-qubit rotation to each physical qubit. TLG are highly desirable since they introduce no overhead and do not spread errors. It has been known before that a quantum code can have only a finite number of TLGs which rules out computational universality. Our scheme circumvents this no-go result by combining TLGs of two different quantum codes using the gauge-fixing method pioneered by Paetznick and Reichardt. The first code, closely related to the 2D color code, enables a transversal implementation of all single-qubit Clifford gates such as the Hadamard gate and the π / 2 phase shift. The second code that we call a doubled color code provides a transversal T-gate, where T is the π / 4 phase shift. The Clifford+T gate set is known to be computationally universal. The two codes can be laid out on the honeycomb lattice with two qubits per site such that the code conversion requires parity measurements for six-qubit Pauli operators supported on faces of the lattice. I will also describe numerical simulations of logical Clifford+T circuits encoded by the distance-3 doubled color code. Based on a joint work with Andrew Cross.

  12. 19. GROUND STORY, POST OFFICE LOBBY DETAIL OF POST OFFICE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. GROUND STORY, POST OFFICE LOBBY DETAIL OF POST OFFICE BOXES ALONG WEST WALL OF LEXINGTON AVENUE ARM - Grand Central Post Office Annex, Forty-fifth Street & Lexington Avenue, Southwest corner, New York County, NY

  13. 16. FLOOR 1; MASSIVE CENTER POST IS THE MAIN POST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. FLOOR 1; MASSIVE CENTER POST IS THE MAIN POST OF A 1736 POST MILL WHICH THIS MILL REPLACED; MORTISE FOR QUARTER BAR CAN BE SEEN - Hook Windmill, North Main Street at Pantigo Road, East Hampton, Suffolk County, NY

  14. Spatio-kinematic modelling of Abell 65, a double-shelled planetary nebula with a binary central star

    NASA Astrophysics Data System (ADS)

    Huckvale, L.; Prouse, B.; Jones, D.; Lloyd, M.; Pollacco, D.; López, J. A.; O'Brien, T. J.; Sabin, L.; Vaytet, N. M. H.

    2013-09-01

    We present the first detailed spatio-kinematical analysis and modelling of the planetary nebula Abell 65, which is known to host a post-common envelope, binary, central star system. As such, this object is of great interest in studying the link between nebular morphology and central star binarity. [O III]5007 Å and Hα+[N II]6584 Å longslit spectra and imagery of Abell 65 were obtained with the Manchester Échelle Spectrometer on the 2.1-m telescope at the San Pedro Martír Observatory (MES-SPM). Further [O III]5007 Å longslit spectra were obtained with the Ultraviolet and Visual Échelle Spectrograph on the Very Large Telescope (VLT-UVES). These data were used to develop a spatio-kinematical model for the [O III]5007 Å emission from Abell 65. A `best-fitting' model was found by comparing synthetic spectra and images rendered from the model to the data. The model comprises an outer shell and an inner shell, with kinematical ages of 15000 ± 5000 yr kpc-1 and 8000 ± 3000 yr kpc-1, respectively. Both shells have peanut-shaped bipolar structures with symmetry axes at inclinations of (55 ± 10)° (to the line of sight) for the outer shell and (68 ± 10)° for the inner shell. The near alignment between the nebular shells and the binary orbital inclination [of (68 ± 2)°] is strongly indicative that the binary is responsible for shaping the nebula. Abell 65 is one of a growing number of planetary nebulae (seven to date, including Abell 65 itself) for which observations and modelling support the shaping influence of a central binary.

  15. Post and Lintel Architecture

    ERIC Educational Resources Information Center

    Daniel, Robert A.

    1973-01-01

    Author finds that children understand architectural concepts more readily when he refers to familiar non-architectural examples of them such as goal posts, chairs, tables, and playground equipment. (GB)

  16. CRITICALITY SAFETY POSTING GUIDELINES

    SciTech Connect

    JENSEN, M.A.

    2001-11-01

    This document provides a set of guidelines in the preparation of criticality safety postings. Guidance is provided in word choice, word arrangement, common human factors considerations. and use of color to highlight limits, cautions, and permissives.

  17. Post-Polio Syndrome

    MedlinePlus

    ... Funding Information Research Programs Training & Career Awards Enhancing Diversity Find People About NINDS NINDS Post-Polio Syndrome ... News From NINDS | Find People | Training | Research | Enhancing Diversity Careers@NINDS | FOIA | Accessibility Policy | Contact Us | Privacy ...

  18. Cryogenic skirt support post

    NASA Astrophysics Data System (ADS)

    Niemann, R. C.; Buckles, W. E.

    The cold masses of cryostats having vertical axes, like vertical pressure vessels, can be effectively supported by means of a cylindrical skirt that wraps concentrically around the cold mass. The skirt is a cryogenic support post connected at its upper end to the cold mass and at its lower end to the cryostat vacuum vessel. A heat intercept connection to an intermediate temperature refrigeration source can be employed to control heat leak. The support post consists of a composite; e.g. epoxy fibreglass, or cylinder with bolted or thermal interference fit end connections. The support post, being a single element support, simplifies cryostat assembly and alignment. The composite cylinder, with a relatively large diameter, lends itself to structural soundness and stability under both static and dynamic loading conditions. Its relatively long length and intermediate temperature heat intercept allows low heat leak to the cold mass. The details of the design of a cryogenic skirt support post as applied to a superconducting magnetic energy storage cryostat are presented. Included are support post fabrication, cryostat assembly, and predicted structural and thermal performance. Fabrication of and operational experiences with a prototype support post assembly are discussed.

  19. The double-mode Cepheids

    NASA Astrophysics Data System (ADS)

    Balona, L. A.

    1985-06-01

    Recent observational and theoretical results on double-mode Cepheids are reviewed. The likelihood that recently proposed candidate Cepheids are indeed Cepheids is evaluated. Periods, period ratios, and semi-amplitudes of the light and radial velocity variations of double-mode Cepheids are given. The physical and pulsational properties of double-mode Cepheids are discussed, reviewing evidence that these stars are Population I objects of high mass and that they all have the same mean effective temperature. The discovery of strong H-alpha emission occurring at seemingly random phases is addressed. Attempts to resolve the mass discrepancy problem of double-mode Cepheids, which results from observations showing that these Cepheids are indistinguishable from normal Cepheids of similar period, are reviewed along with attempts to find the cause of double-mode pulsation.

  20. Latest Double Chooz results

    NASA Astrophysics Data System (ADS)

    Lasserre, Thierry; Double Chooz Collaboration

    2016-05-01

    I report the latest results from the Double Chooz experiment on the θ13 neutrino mixing angle. Two detectors are located at distances of 400 m and 1050 m from the reactor cores of the Chooz nuclear power station (France) to measure the disappearance of electron antineutrinos. The far detector has been taking data since 2011, accumulating a live time of 467.90 days (66.5 GW-ton-year). In this article we focus on the latest measurement using neutrino-induced neutron capture on hydrogen. A new analysis improved the signal efficiency and reduced the backgrounds and systematic uncertainties, leading to sin2 2θ 13 = 0.095+0.039 -0.038. When combined with the Gadolinium-based analysis this leads to sin2 2θ13 = 0.088+0.33 -0.033. The distortion from the prediction above a visible energy of 4 MeV is confirmed. The near detector started data taking in 2014 and first results shall be reported in 2016.

  1. Supported double membranes

    PubMed Central

    Murray, David H.; Tamm, Lukas K.; Kiessling, Volker

    2009-01-01

    Planar model membranes, like supported lipid bilayers and surface-tethered vesicles, have been proven to be useful tools for the investigation of complex biological functions in a significantly less complex membrane environment. In this study, we introduce a supported double membrane system that should be useful for studies that target biological processes in the proximity of two lipid bilayers such as the periplasm of bacteria and mitochondria or the small cleft between pre-and postsynaptic neuronal membranes. Large unilamellar vesicles (LUV) were tethered to a preformed supported bilayer by a biotin-streptavidin tether. We show from single particle tracking (SPT) experiments that these vesicle are mobile above the plane of the supported membrane. At higher concentrations, the tethered vesicles fuse to form a second continuous bilayer on top of the supported bilayer. The distance between the two bilayers was determined by fluorescence interference contrast (FLIC) microscopy to be between 16 and 24 nm. The lateral diffusion of labeled lipids in the second bilayer was very similar to that in supported membranes. SPT experiments with reconstituted syntaxin-1A show that the mobility of transmembrane proteins was not improved when compared with solid supported membranes. PMID:19236921

  2. Laser double Doppler flowmeter

    NASA Astrophysics Data System (ADS)

    Poffo, L.; Goujon, J.-M.; Le Page, R.; Lemaitre, J.; Guendouz, M.; Lorrain, N.; Bosc, D.

    2014-05-01

    The Laser Doppler flowmetry (LDF) is a non-invasive method for estimating the tissular blood flow and speed at a microscopic scale (microcirculation). It is used for medical research as well as for the diagnosis of diseases related to circulatory system tissues and organs including the issues of microvascular flow (perfusion). It is based on the Doppler effect, created by the interaction between the laser light and tissues. LDF measures the mean blood flow in a volume formed by the single laser beam, that penetrate into the skin. The size of this measurement volume is crucial and depends on skin absorption, and is not directly reachable. Therefore, current developments of the LDF are focused on the use of always more complex and sophisticated signal processing methods. On the other hand, laser Double Doppler Flowmeter (FL2D) proposes to use two laser beams to generate the measurement volume. This volume would be perfectly stable and localized at the intersection of the two laser beams. With FL2D we will be able to determine the absolute blood flow of a specific artery. One aimed application would be to help clinical physicians in health care units.

  3. Double acting bit holder

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1994-01-01

    A double acting bit holder that permits bits held in it to be resharpened during cutting action to increase energy efficiency by reducing the amount of small chips produced. The holder consist of: a stationary base portion capable of being fixed to a cutter head of an excavation machine and having an integral extension therefrom with a bore hole therethrough to accommodate a pin shaft; a movable portion coextensive with the base having a pin shaft integrally extending therefrom that is insertable in the bore hole of the base member to permit the moveable portion to rotate about the axis of the pin shaft; a recess in the movable portion of the holder to accommodate a shank of a bit; and a biased spring disposed in adjoining openings in the base and moveable portions of the holder to permit the moveable portion to pivot around the pin shaft during cutting action of a bit fixed in a turret to allow front, mid and back positions of the bit during cutting to lessen creation of small chip amounts and resharpen the bit during excavation use.

  4. Pion double charge exchange reactions leading to double pionic atoms

    SciTech Connect

    Nieves, J.; Oset, E.; Vincente-Vacas, M.J. ); Hirenzaki, S.; Toki, H. )

    1992-10-20

    In this paper, the authors study theoretically pion double charge exchange reactions leading to double pionic atoms. The reaction cross-sections with two pions in the deeper bound pionic orbits in [sup 208]Pb are calculated with realistic pionic atom wave functions and distortion effects. The cross-sections are found to be d[sup 2] [sigma]/dEd[Omega] [approx] 10[sup [minus] 3] [minus] 10[sup [minus] 4] [mu]b/srMeV, which are only a small fraction of the double charge exchange.

  5. Double Radio Sources: Two Approaches

    NASA Astrophysics Data System (ADS)

    Valtonen, M. J.; Heinämäki, P.

    2000-02-01

    The theory of double radio sources is considered from two different points of view: the so called unified models and the slingshot model. First, observations and theory are discussed in 11 areas: (1) the dependence or independence of small-scale and large-scale jets from each other; (2) stability and existence of large-scale jets; (3) radio hot spots inside the lobes of double radio sources; (4) the relation of double-lobed quasars to radio galaxies; (5) polarization and other asymmetries between the two lobes and correlations among them; (6) the speeds of advance of radio lobes; (7) giant radio sources; (8) one-sided double radio sources; (9) multiple-sided double radio sources; (10) the origin of the Fanaroff-Riley classes of radio morphology; and (11) the origin of distance asymmetries of the radio lobes. Then five steps in building up a double radio source theory are discussed: (1) theory of galaxy mergers; (2) theory of black hole mergers; (3) theory of black hole interactions and ejections; (4) theory of radio lobe formation and evolution; and (5) radio jet theory. Finally, recent X-ray observations by ROSAT are discussed from the point of view of double radio source theory.

  6. Post-ERCP pancreatitis.

    PubMed

    Arata, Shinju; Takada, Tadahiro; Hirata, Koichi; Yoshida, Masahiro; Mayumi, Toshihiko; Hirota, Morihisa; Yokoe, Masamichi; Hirota, Masahiko; Kiriyama, Seiki; Sekimoto, Miho; Amano, Hodaka; Wada, Keita; Kimura, Yasutoshi; Gabata, Toshifumi; Takeda, Kazunori; Kataoka, Keisho; Ito, Tetsuhide; Tanaka, Masao

    2010-01-01

    Pancreatitis remains the most common severe complication of endoscopic retrograde cholangiopancreatography (ERCP). Detailed information about the findings of previous studies concerning post-ERCP pancreatitis has not been utilized sufficiently. The purpose of the present article was to present guidelines for the diagnostic criteria of post-ERCP pancreatitis, and its incidence, risk factors, and prophylactic procedures that are supported by evidence. To achieve this purpose, a critical examination was made of the articles on post-ERCP pancreatitis, based on the data obtained by research studies published up to 2009. At present, there are no standardized diagnostic criteria for post-ERCP pancreatitis. It is appropriate that post-ERCP pancreatitis is defined as acute pancreatitis that has developed following ERCP, and its diagnosis and severity assessment should be made according to the diagnostic criteria and severity assessment of the Japanese Ministry of Health, Labour and Welfare. The incidence of acute pancreatitis associated with diagnostic and therapeutic ERCP is 0.4-1.5 and 1.6-5.4%, respectively. Endoscopic papillary balloon dilation is associated with a high risk of acute pancreatitis compared with endoscopic sphincterotomy. It was made clear that important risk factors include dysfunction of the Oddi sphincter, being of the female sex, past history of post-ERCP pancreatitis, and performance of pancreaticography. Temporary prophylactic placement of pancreatic stents in the high-risk group is useful for the prevention of post-ERCP pancreatitis [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.6-6.4, number needed to treat (NNT) 10]. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduction in the development of post-ERCP pancreatitis (OR 0.46, 95% CI 0.32-0.65). Single rectal administration of NSAIDs is useful for the prevention of post-ERCP pancreatitis [relative risk (RR) 0.36, 95% CI 0.22-0.60, NNT 15] and decreases the

  7. Advanced double layer capacitors

    NASA Technical Reports Server (NTRS)

    Sarangapani, S.; Lessner, P.; Forchione, J.; Laconti, A. B.

    1989-01-01

    There is a need for large amounts of power to be delivered rapidly in a number of airborne and space systems. Conventional, portable power sources, such as batteries, are not suited to delivering high peak power pulses. The charge stored at the electrode-electrolyte double layer is, however, much more assessible on a short time scale. Devices exploiting this concept were fabricated using carbon and metal oxides (Pinnacle Research) as the electrodes and sulfuric acid as the electrolyte. The approach reported, replaces the liquid sulfuric acid electrolyte with a solid ionomer electrolyte. The challenge is to form a solid electrode-solid ionomer electrolyte composite which has a high capacitance per geometric area. The approach to maximize contact between the electrode particles and the ionomer was to impregnate the electrode particles using a liquid ionomer solution and to bond the solvent-free structure to a solid ionomer membrane. Ruthenium dioxide is the electrode material used. Three strategies are being pursued to provide for a high area electrode-ionomer contact: mixing of the RuOx with a small volume of ionomer solution followed by filtration to remove the solvent, and impregnation of the ionomer into an already formed RuOx electrode. RuOx powder and electrodes were examined by non-electrochemical techniques. X-ray diffraction has shown that the material is almost pure RuO2. The electrode structure depends on the processing technique used to introduce the Nafion. Impregnated electrodes have Nafion concentrated near the surface. Electrodes prepared by the evaporation method show large aggregates of crystals surrounded by Nafion.

  8. [Post bariatric body contouring.

    PubMed

    Winge, Rikke; Henriksen, Trine Foged; Printzlau, Andreas; Hülmich, Lisbet

    2014-03-17

    Post bariatric body contouring in Denmark is currently a field under development. The scope of this article is to give an overview of existing plastic surgery techniques being used to treat patients with massive weight loss, as well as the current indications for patient referral. Furthermore, we describe how to optimise the preoperative evaluation of the patient and give a brief description of potential surgical adverse effects and their prevalence. Further research can provide this field with invaluable data regarding the post-operative effects on patient rehabilitation and quality of life. PMID:25096208

  9. Three step double layers in the laboratory

    NASA Astrophysics Data System (ADS)

    Bailey, Andrew, III; Hershkowitz, Noah

    1988-01-01

    A new class of stationary double layer structure, with three or more distinct steps, is demonstrated in the laboratory. A large monotonic potential increase results from a series of smaller double layers. In many respects, these double layer structures resemble those inferred from satellite measurements of auroral double layers. This new class of double layer appears to depend on turbulence for its existence and to be a hybrid structure, intermediate between anomalous resistivity and BGK double layers.

  10. Species doubling and effective Lagrangians

    SciTech Connect

    Creutz, M.; Tytgat, M.

    1996-09-01

    Coupling gauge fields to the chiral currents from an effective Lagrangian for pseudoscalar mesons naturally gives rise to a species doubling phenomenon similar to that seen with fermionic fields in lattice gauge theory. 17 refs.

  11. A Double Pendulum "Art Machine"

    ERIC Educational Resources Information Center

    Romer, R. H.

    1970-01-01

    Describes a double pendulum apparatus and its mode of operation to produce a great variety of figures similar to Lissajous figures. The author suggests that several advanced physics topics can be studied with the aid of this instrument. Bibliography. (LC)

  12. Entanglement purification with double selection

    SciTech Connect

    Fujii, Keisuke; Yamamoto, Katsuji

    2009-10-15

    We investigate an entanglement purification protocol with double-selection process, which works under imperfect local operations. Compared with the usual protocol with single selection, this double-selection method has higher noise thresholds for the local operations and quantum communication channels and achieves higher fidelity of purified states. It also provides a yield comparable to that of the usual protocol with single selection. We discuss on general grounds how some of the errors which are introduced by local operations are left as intrinsically undetectable. The undetectable errors place a general upper bound on the purification fidelity. The double selection is a simple method to remove all the detectable errors in the first order, so that the upper bound on the fidelity is achieved in the low-noise regime. The double selection is further applied to purification of multipartite entanglement such as two-colorable graph states.

  13. Simulation of auroral double layers

    NASA Technical Reports Server (NTRS)

    Hubbard, R. F.; Joyce, G.

    1979-01-01

    Some basic properties of plasma double layers are deduced from a particle-in-cell computer simulation and related to parallel electric-field structures above the auroral regions. The simulation results on the processes leading to double-layer formation are examined, particularly in relation to the transient stage and double-layer structure and stability. It is concluded that: (1) a large potential difference applied to a finite-length plasma will be concentrated in a shocklike localized region instead of occurring over the entire length of the system; (2) the initial stage in double-layer formation is dominated by a large-potential pulse propagating in the direction of the induced electrostatic drift; (3) the entire potential is dropped over a specific scale length once the double layer has formed; and (4) this scale length is expected to be of the order of 1 km for a double layer above a discrete auroral arc with a potential of 10 kV and the electric-field vector parallel to the magnetic-field vector.

  14. Effects of a single administration of prostaglandin F2alpha, or a combination of prostaglandin F2alpha and prostaglandin E2, or placebo on fertility variables in dairy cows 3–5 weeks post partum, a randomized, double-blind clinical trial

    PubMed Central

    Hirsbrunner, Gaby; Burkhardt, Heinz W; Steiner, Adrian

    2006-01-01

    Background Delayed uterine involution has negative effects on the fertility of cows; use of prostaglandin F2alpha alone as a single treatment has not been shown to consistently improve fertility. Combined administration of PGF2alpha and PGE2 increased uterine pressure in healthy cows. We hypothesized, that the combination of both prostaglandins would accelerate uterine involution and have, therefore, a positive effect on fertility variables. In commercial dairy farming, the benefit of a single post partum combined prostaglandin treatment should be demonstrated. Methods 383 cows from commercial dairy farms were included in this study. Uterine size and secretion were evaluated at treatment 21–35 days post partum and 14 days later. Cows were randomly allocated to one of three treatment groups: PGF2alpha and PGE2, PGF2alpha or placebo. For every animal participating in the study, the following reproduction variables were recorded: Interval from calving to first insemination, days open, number of artificial inseminations (AI) to conception; subsequent treatment of uterus, subsequent treatment of ovaries. Plasma progesterone level at time of treatment was used as a covariable. For continuous measurements, analysis of variance was performed. Fisher's exact test for categorical non-ordered data and exact Kruskal-Wallis test for ordered data were used; pairwise group comparisons with Bonferroni adjustment of significance level were performed. Results There was no significant difference among treatment groups in uterine size. Furthermore, there was no significant difference among treatments concerning days open, number of AI, and subsequent treatment of uterus and ovaries. Days from calving to first insemination tended to be shorter for cows with low progesterone level given PGF2alpha and PGE2 in combination than for the placebo-group (P = 0.024). Conclusion The results of this study indicate that the administration of PGF2alpha or a combination of PGF2alpha and PGE2 21 to

  15. The double burden.

    PubMed

    Faurholt-Jepsen, Daniel

    2013-07-01

    parameters. The population was followed up during treatment (2 and 5 months) to assess treatment outcome as well as after one year to assess their survival status. Based on data from 1,250 tuberculosis patients and 350 neighbourhood controls, we found that 38 and 21%, respectively, had impaired glycaemia, and that the prevalence of diabetes was 17 and 9% among tuberculosis patients and controls, respectively. This difference in prevalence between patients and controls was equivalent to an adjusted odds ratio of more than four, indicating a strong association between tuberculosis and diabetes. Furthermore, we found that diabetes was associated with tuberculosis among both participants with or without HIV co-infection. Despite the strong association, diabetes had only moderate clinical implications when the tuberculosis patients initiated the tuberculosis treatment; the patients with diabetes co-morbidity had a minor elevation in the immune response and more frequently reported to have fever. Furthermore, diabetes did not seem to delay time to sputum conversion during treatment. Nevertheless, diabetes co-morbidity led to impaired treatment outcome with slower recovery of weight and haemoglobin and a more than four times higher mortality rate within the initial phase of tuberculosis treatment. In conclusion, in the African region, the double burden of tuberculosis and diabetes is becoming a major health problem. Although the tuberculosis incidence has stabilized during the last decade, the increasing incidence of diabetes will possibly interfere with tuberculosis control and may, consequently, make the tuberculosis incidence increase again. Future research strategies should focus on enhanced diagnostic tools to identify tuberculosis patients with diabetes co-morbidity, and on the role of disease-disease, drug-disease and drug-drug interactions between tuberculosis and diabetes diseases and treatments. PMID:23809978

  16. Early (≤ 1-h) vs. late (>1-h) administration of frovatriptan plus dexketoprofen combination vs. frovatriptan monotherapy in the acute treatment of migraine attacks with or without aura: a post hoc analysis of a double-blind, randomized, parallel group study.

    PubMed

    Allais, Gianni; Bussone, Gennaro; Tullo, Vincenzo; Cortelli, Pietro; Valguarnera, Fabio; Barbanti, Piero; Sette, Giuliano; Frediani, Fabio; D'Arrigo, Giacomo; d'Onofrio, Florindo; Comi, Giancarlo; Curone, Marcella; Colombo, Bruno; Omboni, Stefano; Benedetto, Chiara

    2015-05-01

    The early use of triptan in combination with a nonsteroidal anti-inflammatory drug after headache onset may improve the efficacy of acute migraine treatment. In this retrospective analysis of a randomized, double-blind, parallel group study, we assessed the efficacy of early or late intake of frovatriptan 2.5 mg + dexketoprofen 25 or 37.5 mg (FroDex 25 and FroDex 37.5) vs. frovatriptan 2.5 mg alone (Frova) in the acute treatment of migraine attacks. In this double-blind, randomized parallel group study 314 subjects with acute migraine with or without aura were randomly assigned to Frova, FroDex 25, or FroDex 37.5. Pain free (PF) at 2-h (primary endpoint), PF at 4-h and pain relief (PR) at 2 and 4-h, speed of onset at 60, 90, 120 and 240-min, and sustained pain free (SPF) at 24-h were compared across study groups according to early (≤1-h; n = 220) or late (>1-h; n = 59) intake. PF rates at 2 and 4-h were significantly larger with FroDex 37.5 vs. Frova (early intake, n = 71 FroDex 37.5 and n = 75 Frova: 49 vs. 32 % and 68 vs. 52 %, p < 0.05; late intake, n = 20 Frodex 37.5, and n = 18 Frova: 55 vs. 17 %, p < 0.05 and 85 vs. 28 %, p < 0.01). Also with FroDex 25, in the early intake group (n = 74) PF episodes were significantly higher than Frova. PR at 2 and 4-h was significantly better under FroDex 37.5 than Frova (95 % vs. 50 %, p < 0.001, 100 % vs. 72 %, p < 0.05) in the late intake group (n = 21). SPF episodes at 24-h after early dosing were 25 % (Frova), 45 % (FroDex 25) and 41 % (FroDex 37.5, p < 0.05 combinations vs. monotherapy), whereas they were not significantly different with late intake. All treatments were equally well tolerated. FroDex was similarly effective regardless of intake timing from headache onset. PMID:26017535

  17. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  18. 1. Post card view of the bridge, c. 1910. Post ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Post card view of the bridge, c. 1910. Post card courtesy Carol Poh Miller. Photocopy by Berni Rich, Score Photographers Cleveland, OH - B & O Railroad Bridge Number 464, Spanning Old Ship Canal & Cuyahoga River, Cleveland, Cuyahoga County, OH

  19. 10. FLOOR 1; CENTER POST AND POSTS UNDER STONE BEAMS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. FLOOR 1; CENTER POST AND POSTS UNDER STONE BEAMS WHICH SUPPORT BRIDGE BEAMS FOR BRIDGE TREES; WEDGES FOR ADJUSTING HEIGHT OF BRIDGE TREE CAN BE SEEN - Shelter Island Windmill, Manwaring Road, Shelter Island, Suffolk County, NY

  20. 78 FR 2950 - Proposed Posting and Posting of Stockyards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-15

    ... posted the stockyards. On January 26, 2010, we published a notice in the Federal Register (75 FR 4039... posting AZ-117 Robertson Horse Sales, Benson, April 28, 2010. Arizona. CA-193 Westside Auction...

  1. Typical Newel Post, First Floor Newel Post, Typical Baluster, Typical ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Typical Newel Post, First Floor Newel Post, Typical Baluster, Typical Nosing, First Floor Stringer Profile, Second Floor Stringer Profile - National Home for Disabled Volunteer Soldiers - Battle Mountain Sanitarium, Treasurer's Quarters, 500 North Fifth Street, Hot Springs, Fall River County, SD

  2. Double metric, generalized metric, and α' -deformed double field theory

    NASA Astrophysics Data System (ADS)

    Hohm, Olaf; Zwiebach, Barton

    2016-03-01

    We relate the unconstrained "double metric" of the "α' -geometry" formulation of double field theory to the constrained generalized metric encoding the spacetime metric and b -field. This is achieved by integrating out auxiliary field components of the double metric in an iterative procedure that induces an infinite number of higher-derivative corrections. As an application, we prove that, to first order in α' and to all orders in fields, the deformed gauge transformations are Green-Schwarz-deformed diffeomorphisms. We also prove that to first order in α' the spacetime action encodes precisely the Green-Schwarz deformation with Chern-Simons forms based on the torsionless gravitational connection. This seems to be in tension with suggestions in the literature that T-duality requires a torsionful connection, but we explain that these assertions are ambiguous since actions that use different connections are related by field redefinitions.

  3. Hemiparesis post cerebral malaria

    PubMed Central

    Taiaa, Oumkaltoum; Amil, Touriya; Darbi, Abdelatif

    2015-01-01

    Cerebral malaria is one of the most serious complications in the Plasmodium falciparum infection. In endemic areas, the cerebral malaria interested mainly children. The occurrence in adults is very rare and most interested adult traveling in tropical zones. This case report describes a motor deficit post cerebral malaria in a young adult traveling in malaria endemic area. This complication has been reported especially in children and seems very rare in adults. PMID:25995798

  4. Post-transplant hyperlipidaemia.

    PubMed Central

    Jindal, R. M.

    1997-01-01

    The correction of post-transplant hyperlipidaemia warrants the judicious and timely use of pharmacological agents with dietary modification and exercise. Reduction in hyperlipidaemia may have some role in decreasing the incidence of chronic rejection of allografts. The awareness that the morbidity and mortality of atherosclerotic disease may be lowered by active intervention will result in a better quality of life for transplant recipients. PMID:9497947

  5. 32 CFR 199.8 - Double coverage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Double coverage. 199.8 Section 199.8 National... CIVILIAN HEALTH AND MEDICAL PROGRAM OF THE UNIFORMED SERVICES (CHAMPUS) § 199.8 Double coverage. (a... insurance plans do not exceed the total charges. (b) Double coverage plan. A double coverage plan is one...

  6. 32 CFR 199.8 - Double coverage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Double coverage. 199.8 Section 199.8 National... CIVILIAN HEALTH AND MEDICAL PROGRAM OF THE UNIFORMED SERVICES (CHAMPUS) § 199.8 Double coverage. (a... insurance plans do not exceed the total charges. (b) Double coverage plan. A double coverage plan is one...

  7. 32 CFR 199.8 - Double coverage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Double coverage. 199.8 Section 199.8 National... CIVILIAN HEALTH AND MEDICAL PROGRAM OF THE UNIFORMED SERVICES (CHAMPUS) § 199.8 Double coverage. Link to an... charges. (b) Double coverage plan. A double coverage plan is one of the following: (1) Insurance plan....

  8. Anti-spacer double patterning

    NASA Astrophysics Data System (ADS)

    Hyatt, Michael; Huang, Karen; DeVilliers, Anton; Slezak, Mark; Liu, Zhi

    2014-03-01

    With extreme UV not ready for HVM for the 20nm and 14nm nodes, double patterning options that extend the use of 193nm immersion lithography beyond the optical resolution limits, such as LELE (Litho-Etch-Litho-Etch) and SADP (Self Aligned Double Patterning), are being used for critical layers for these nodes. LELE requires very stringent overlay capability of the optical exposure tool. The spacer scheme of SADP starts with a conformal film of material around the mandrels and etched along the mandrel sidewalls to form patterns with doubled frequency. SADP, while having the advantage of being a self-aligned process, adds a number of process steps and strict control of the mandrel profile is required. In this paper, we will demonstrate a novel technique - ASDP (Anti-Spacer Double Patterning), which uses only spin-on materials to achieve self-aligned double patterning. After initial resist patterning, an Anti-Spacer Generator (ASG) material is coated on the resist pattern to create the developable spacer region. Another layer of material is then coated and processed to generate the second pattern in between the first resist pattern. We were able to define 37.5nm half pitch pattern features using this technique as well as sub-resolution features for an asymmetric pattern. In this paper we will review the capability of the process in terms of CD control and LWR (line width roughness) and discuss the limitations of the process.

  9. First results from the new double velocity-double energy spectrometer VERDI

    NASA Astrophysics Data System (ADS)

    Frégeau, M. O.; Oberstedt, S.; Gamboni, Th.; Geerts, W.; Hambsch, F.-J.; Vidali, M.

    2016-05-01

    The VERDI spectrometer (VElocity foR Direct mass Identification) is a two arm time-of-flight spectrometer built at the European Commission Joint Research Centre IRMM. It determines fragment masses and kinetic energy distributions produced in nuclear fission by means of the double velocity and double energy (2v-2E) method. The simultaneous measurement of pre- and post neutron fragment characteristics allows studying the share of excitation energy between the two fragments. In particular, the evolution of fission modes and neutron multiplicity may be studied as a function of the available excitation energy. Both topics are of great importance for the development of models used in the evaluation of nuclear data, and also have important implications for the fundamental understanding of the fission process. The development of VERDI focus on maximum geometrical efficiency while striving for highest possible mass resolution. An innovative transmission start detector, using electrons ejected from the target itself, was developed. Stop signal and kinetic energy of both fragments are provided by two arrays of silicon detectors. The present design provides about 200 times higher geometrical efficiency than that of the famous COSI FAN TUTTE spectrometer [Nuclear Instruments and Methods in Physics Research 219 (1984) 569]. We report about a commissioning experiment of the VERDI spectrometer, present first results from a 2v-2E measurement of 252Cf spontaneous fission and discuss the potential of this instrument to contribute to the investigation prompt fission neutron characteristics as a function of fission fragment properties.

  10. New double soft emission theorems

    NASA Astrophysics Data System (ADS)

    Cachazo, Freddy; He, Song; Yuan, Ellis Ye

    2015-09-01

    We study the behavior of the tree-level S-matrix of a variety of theories as two particles become soft. By analogy with the recently found subleading soft theorems for gravitons and gluons, we explore subleading terms in double soft emissions. We first consider double soft scalar emissions and find subleading terms that are controlled by the angular momentum operator acting on hard particles. The order of the subleading theorems depends on the presence or not of color structures. Next we obtain a compact formula for the leading term in a double soft photon emission. The theories studied are a special Galileon, Dirac-Born-Infeld, Einstein-Maxwell-Scalar, nonlinear sigma model and Yang-Mills-Scalar. We use the recently found Cachazo-He-Yuan representation of these theories in order to give a simple proof of the leading order part of all these theorems.

  11. Double patterning compliant logic design

    NASA Astrophysics Data System (ADS)

    Ma, Yuangsheng; Sweis, Jason; Bencher, Chris; Deng, Yunfei; Dai, Huixiong; Yoshida, Hidekazu; Gisuthan, Bimal; Kye, Jongwook; Levinson, Harry J.

    2011-04-01

    Double patterning technology (DPT) is the only solution to enable the scaling for advanced technology nodes before EUV or any other advanced patterning techniques become available. In general, there are two major double patterning techniques: one is Litho-Etch-Litho-Etch (LELE), and the other is sidewall spacer technology, a Self-Aligned Double Patterning technique (SADP). While numerous papers have previously demonstrated these techniques on wafer process capabilities and processing costs, more study needs to be done in the context of standard cell design flow to enable their applications in mass production. In this paper, we will present the impact of DPT on logic designs, and give a thorough discussion on how to make DPT-compliant constructs, placement and routing using examples with Cadence's Encounter Digital Implementation System (EDI System).

  12. Double ionization of atomic cadmium

    SciTech Connect

    Linusson, P.; Fritzsche, S.; Eland, J. H. D.; Hedin, L.; Karlsson, L.; Feifel, R.

    2011-02-15

    We have recorded the double photoionization spectrum of atomic Cd at four different photon energies in the range 40-200 eV. The main channel is single ionization and subsequent decay of excited Cd{sup +} states, some involving Coster-Kronig processes, whereas direct double ionization is found to be weak. The decay of the excited Cd{sup +} states shows a strong selectivity, related to the configuration of the final state. Double ionization leading to the Cd{sup 2+} ground state is investigated in some detail and is found to proceed mainly through ionization and decay of 4d correlation satellites. The most prominent autoionization peaks have been identified with the aid of quantum-mechanical calculations.

  13. Attosecond Double-Slit Experiment

    SciTech Connect

    Lindner, F.; Schaetzel, M.G.; Baltuska, A.; Goulielmakis, E.; Walther, H.; Krausz, F.; Milosevic, D.B.; Bauer, D.; Becker, W.; Paulus, G.G.

    2005-07-22

    A new scheme for a double-slit experiment in the time domain is presented. Phase-stabilized few-cycle laser pulses open one to two windows (slits) of attosecond duration for photoionization. Fringes in the angle-resolved energy spectrum of varying visibility depending on the degree of which-way information are measured. A situation in which one and the same electron encounters a single and a double slit at the same time is observed. The investigation of the fringes makes possible interferometry on the attosecond time scale. From the number of visible fringes, for example, one derives that the slits are extended over about 500 as.

  14. Double stranded nucleic acid biochips

    DOEpatents

    Chernov, Boris; Golova, Julia

    2006-05-23

    This invention describes a new method of constructing double-stranded DNA (dsDNA) microarrays based on the use of pre-synthesized or natural DNA duplexes without a stem-loop structure. The complementary oligonucleotide chains are bonded together by a novel connector that includes a linker for immobilization on a matrix. A non-enzymatic method for synthesizing double-stranded nucleic acids with this novel connector enables the construction of inexpensive and robust dsDNA/dsRNA microarrays. DNA-DNA and DNA-protein interactions are investigated using the microarrays.

  15. Double-Chooz Neutrino Experiment

    NASA Astrophysics Data System (ADS)

    Palomares, Carmen; Double Chooz Collaboration

    2011-12-01

    The Double Chooz experiment will use the electron anti-neutrinos produced by the Chooz nuclear power station to search for a non-vanishing value of the θ13 neutrino mixing angle. Double Chooz will be the first of a new generation of neutrino experiments using identical detectors at different distances from the neutrino source to reduce the systematic errors due to the uncertainties on the neutrino flux and to the detector acceptance. The far detector will be operative by the beginning of 2011. Installation of the near detector will occur in 2012.

  16. INC424 for Patients With Myelofibrosis, Post Polycythemia Myelofibrosis or Post-essential Thrombocythemia Myelofibrosis

    ClinicalTrials.gov

    2016-05-24

    Myelofibrosis (PMF); Post Polycythemia Myelofibrosis (PPV MF); Post-essential Thrombocythemia Myelofibrosis (PET-MF); Myelofibrosis; Post Polycythemia Myelofibrosis; Post-essential Thrombocythemia Myelofibrosis

  17. POST TRAUMATIC HYPERACTIVE DELIRIUM

    PubMed Central

    Sabhesan, S.; Natarajan, M.

    1990-01-01

    SUMMMARY Hyperactive delirium following head injury is a common problem during the early recovery phase. Twenty-nine patients who evinced hyperactive delirium were prospectively followed up during; their stay In the hospital. Compared with controls, alcohol dependence was significantly more among these patients. Occurrence of delirium was related to the generalized cerebral disturbances; due to diffuse damage in acceleration injuries and due to metabolic or post-seizure disturbances in contact injuries. Follow-up of these patients showed that psychiatric problems were more common among them. PMID:21927482

  18. Post traumatic hyperactive delirium.

    PubMed

    Sabhesan, S; Natarajan, M

    1990-10-01

    Hyperactive delirium following head injury is a common problem during the early recovery phase. Twenty-nine patients who evinced hyperactive delirium were prospectively followed up during; their stay In the hospital. Compared with controls, alcohol dependence was significantly more among these patients. Occurrence of delirium was related to the generalized cerebral disturbances; due to diffuse damage in acceleration injuries and due to metabolic or post-seizure disturbances in contact injuries. Follow-up of these patients showed that psychiatric problems were more common among them. PMID:21927482

  19. Biphoton double-slit experiment

    SciTech Connect

    Brida, G.; Cagliero, E.; Falzetta, G.; Genovese, M.; Gramegna, M.; Predazzi, E.

    2003-09-01

    In this paper we present a double-slit experiment where two indistinguishable photons produced by type-I parametric down-conversion are each sent to a well-defined slit. Data about the diffraction and interference patterns for coincidences are presented and discussed. An analysis of these data allows a test of standard quantum mechanics against the de Broglie-Bohm theory.

  20. A Double-Minded Fractal

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    This article presents a fun activity of generating a double-minded fractal image for a linear algebra class once the idea of rotation and scaling matrices are introduced. In particular the fractal flip-flops between two words, depending on the level at which the image is viewed. (Contains 5 figures.)

  1. The double well mass filter

    SciTech Connect

    Gueroult, Renaud; Fisch, Nathaniel J.; Rax, Jean-Marcel

    2014-02-15

    Various mass filter concepts based on rotating plasmas have been suggested with the specific purpose of nuclear waste remediation. We report on a new rotating mass filter combining radial separation with axial extraction. The radial separation of the masses is the result of a “double-well” in effective radial potential in rotating plasma with a sheared rotation profile.

  2. Double heterojunction bipolar phototransistor model

    NASA Astrophysics Data System (ADS)

    Horak, Michal

    2003-07-01

    An analytical mathematical model of the double heterojunction NpN bipolar phototransistor with abrupt heterojunctions in three terminal configuration is presented. The thermionic-filed emission and diffusion of injected carriers is considered and the Ebers-Moll type relations for the collector and emitter current are obtained. Several steady state characteristics of the phototransistor structure are calculated (optical gain, quantum efficiency, responsivity).

  3. The double well mass filter

    DOE PAGESBeta

    Gueroult, Renaud; Rax, Jean -Marcel; Fisch, Nathaniel J.

    2014-02-03

    Various mass filter concepts based on rotating plasmas have been suggested with the specific purpose of nuclear waste remediation. We report on a new rotating mass filter combining radial separation with axial extraction. Lastly, the radial separation of the masses is the result of a “double-well” in effective radial potential in rotating plasma with a sheared rotation profile.

  4. [Post Stroke Dementia].

    PubMed

    Ihara, Masafumi

    2016-07-01

    Post-stroke dementia (PSD) is a clinical entity that encompasses all types of dementia following an index stroke. Current evidence suggests that 25-30% of ischemic stroke survivors develop immediate or delayed vascular cognitive impairment or vascular dementia. The type of stroke can be either ischemic, hemorrhagic or hypoperfusive. There are multiple risk factors for PSD including older age, family history, genetic variants, low educational status, vascular comorbidities, prior transient ischemic attack or recurrent stroke and depressive illness. Pre-stroke dementia refers to the occurrence of cognitive impairment before the index stroke, which may be caused by a vascular burden as well as insidious neurodegenerative changes. Neuroimaging determinants of dementia after stroke include silent brain infarcts, white matter changes, lacunar infarcts and medial temporal lobe atrophy. Published clinical trials have not been promising and there is little information on whether PSD can be prevented using pharmacological agents. Control of vascular disease risk and prevention of recurrent strokes are key to reducing the burden of cognitive decline and post-stroke dementia. Modern imaging and analysis techniques will help to elucidate the mechanism of PSD and establish better treatment. PMID:27395459

  5. Keepers of the double stars

    NASA Astrophysics Data System (ADS)

    Tenn, Joseph S.

    2013-03-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Early catalogues by the Herschels, Struves, and others began with their own discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley Burnham published a massive double star catalogue containing data from many observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant Aitken produced a much larger catalogue in 1932 and coordinated with Robert Innes of Johannesburg, who catalogued the southern systems. Aitken maintained and expanded Burnham's records of observations on handwritten file cards, and eventually turned them over to the Lick Observatory, where astrometrist Hamilton Jeffers further expanded the collection and put all the observations on punched cards. With the aid of Frances M. "Rete" Greeby he made two catalogues: an Index Catalogue with basic data about each star, and a complete catalogue of observations, with one observation per punched card. He enlisted Willem van den Bos of Johannesburg to add southern stars, and together they published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers approached retirement he became greatly concerned about the disposition of the catalogues. He wanted to be replaced by another "double star man," but Lick Director Albert E. Whitford had the new 120-inch reflector, the world's second largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers was vociferously opposed to turning over the card files to another institution, and especially against their coming under the control of Kaj Strand of the United States Naval Observatory. In the end the USNO got the files and has maintained the records ever since, first under Charles Worley, and, since 1997, under Brian Mason. Now called the Washington Double Star Catalog (WDS), it is completely online and currently contains more than 1,200,000 measures of more than 125

  6. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable, and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable, and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam, and the beam plasma discharge is ignited.

  7. A laboratory investigation of potential double layers

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1987-01-01

    In a triple plasma device, the injection of electron current from the source chamber to the target chamber causes the formation of a potential double layer. At a low current density, the space charge of the injected current produces a virtual cathode-type potential double layer. This double layer is stable and various wave instabilities are observed to associate with this double layer. As the current density is increased, the double layer becomes unstable and a moving double layer results. As the current density is increased further, the enhanced ionization causes the neutralization of the space charge of the electron beam and the 'beam plasma discharge' is ignited.

  8. Double Photoionization into Double Core-Hole States in Xe

    SciTech Connect

    Hikosaka, Y.; Kaneyasu, T.; Shigemasa, E.; Lablanquie, P.; Penent, F.; Eland, J. H. D.; Aoto, T.; Ito, K.

    2007-05-04

    Double photoionization (DPI) leading to double core-hole states of Xe{sup 2+} 4d{sup -2} has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe{sup 2+} 4d{sup -2} states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe{sup 2+} 4d{sup -2} at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d{sup -2} continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe{sup 2+} 4d{sup -2} components.

  9. Double photoionization into double core-hole states in Xe.

    PubMed

    Hikosaka, Y; Lablanquie, P; Penent, F; Kaneyasu, T; Shigemasa, E; Eland, J H D; Aoto, T; Ito, K

    2007-05-01

    Double photoionization (DPI) leading to double core-hole states of Xe2+ 4d(-2) has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe2+ 4d(-2) states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe2+ 4d(-2) at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d(-2) continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe2+ 4d(-2) components. PMID:17501570

  10. Post retention and post/core shear bond strength of four post systems.

    PubMed

    Stockton, L W; Williams, P T; Clarke, C T

    2000-01-01

    As clinicians we continue to search for a post system which will give us maximum retention while maximizing resistance to root fracture. The introduction of several new post systems, with claims of high retentive and resistance to root fracture values, require that independent studies be performed to evaluate these claims. This study tested the tensile and shear dislodgment forces of four post designs that were luted into roots 10 mm apical of the CEJ. The Para Post Plus (P1) is a parallel-sided, passive design; the Para Post XT (P2) is a combination active/passive design; the Flexi-Post (F1) and the Flexi-Flange (F2) are active post designs. All systems tested were stainless steel. This study compared the test results of the four post designs for tensile and shear dislodgment. All mounted samples were loaded in tension until failure occurred. The tensile load was applied parallel to the long axis of the root, while the shear load was applied at 450 to the long axis of the root. The Flexi-Post (F1) was significantly different from the other three in the tensile test, however, the Para Post XT (P2) was significantly different to the other three in the shear test and had a better probability for survival in the Kaplan-Meier survival function test. Based on the results of this study, our recommendation is for the Para Post XT (P2). PMID:11203854

  11. Isolated post resonator mesogyroscope

    NASA Technical Reports Server (NTRS)

    Challoner, Dorian; Peay, Chris; Wellman, Joanne; Shcheglov, Kirill; Hayworth, Ken; Wiberg, Dean; Yee, Karl; Sipppola, Clayton

    2004-01-01

    A new symmetric vibratory gyroscope principle has been devised in which a central post proof mass is counter-rocked against an outer sensing plate such that the motion is isolated from the gyroscope case. Prototype gyroscopes have been designed and fabricated with micromachined silicon at mesoscale (20-cm resonator width), vs. microscale (e.g., 2-mm resonator width) to achieve higher sensitivity and machined precision. This novel mesogyro design arose out of an ongoing technical cooperation between JPL and Boeing begun in 1997 to advance the design of micro-inertial sensors for low-cost space applications. This paper describes the theory of operation of the mesogyro and relationships with other vibratory gyroscopes, the mechanical design, closed loop electronics design, bulk silicon fabrication and packaged gyroscope assembly and test methods. The initial packaged prototype test results are reported for what is believed to be the first silicon mesogyroscope.

  12. Post dengue neurological complication.

    PubMed

    Hasliza, A H; Tohid, H; Loh, K Y; Santhi, P

    2015-01-01

    Dengue infection is highly endemic in many tropical countries including Malaysia. However, neurological complications arising from dengue infection is not common; Gullain-Barre syndrome (GBS) is one of these infrequent complications. In this paper, we have reported a case in which a 39-year-old woman presented with a neurological complication of dengue infection without typical symptoms and signs of dengue fever. She had a history of acute gastroenteritis (AGE) followed by an upper respiratory tract infection (URTI) weeks prior to her presentation rendering GBS secondary to the post viral URTI and AGE as the most likely diagnosis. Presence of thrombocytopenia was the only clue for dengue in this case. PMID:27099661

  13. Post traumatic stress disorder.

    PubMed

    Tiller, J; Kyrios, M; Bennett, P

    1996-10-01

    Post traumatic stress disorder (PTSD) occurs after a person has been exposed to a traumatic event involving actual or threatened death, and has responded with intense fear or helplessness. The event is then persistently re-experienced. The person avoids stimuli associated with the trauma and experiences a numbing of general responsiveness. Symptoms of increased arousal can occur as well as depression and anxiety. PTSD causes clinically significant distress or impairment in social, occupational, or other important areas of functioning. The general practitioner is uniquely placed to identify PTSD and can have a key role in treatment. Cognitive behavioural treatment is a central therapeutic approach and can be carried out in general practice. The issues are to counteract the physiological components, expose the patient to the feared situation and help the patient to relearn that the stimuli are not necessarily associated with danger or threat. Repeated brief consultations over time can facilitate this process. PMID:8936738

  14. Post-stroke depression.

    PubMed

    Gaete, Jorge Moncayo; Bogousslavsky, Julien

    2008-01-01

    Post-stroke depression (PSD) is among the most common emotional disorders afflicting stroke sufferers. Approximately one third of stroke survivors experience an early or later onset of depression. PSD impedes the rehabilitation and recovery process, jeopardizes quality of life and increases mortality. Diagnosis of PSD is challenging in the acute and chronic aftermath. Therefore, it often remains unrecognized and/or undertreated. The interaction between depression and stroke is very complex and the pathophysiological mechanisms have not as yet been fully elucidated, although an interaction between anatomical and psychosocial factors may be important in PSD development. Neurochemical changes and clinical findings are similar to endogenous depression. PSD is potentially treatable, although no conclusive benefits of antidepressant agents and nonpharmacological interventions have been observed. The efficacy of preventive strategies in PSD remains essentially undetermined. PMID:18088202

  15. Double layers and double wells in arbitrary degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2016-06-01

    Using the generalized hydrodynamic model, the possibility of variety of large amplitude nonlinear excitations is examined in electron-ion plasma with arbitrary electron degeneracy considering also the ion temperature effect. A new energy-density relation is proposed for plasmas with arbitrary electron degeneracy which reduces to the classical Boltzmann and quantum Thomas-Fermi counterparts in the extreme limits. The pseudopotential method is employed to find the criteria for existence of nonlinear structures such as solitons, periodic nonlinear structures, and double-layers for different cases of adiabatic and isothermal ion fluids for a whole range of normalized electron chemical potential, η0, ranging from dilute classical to completely degenerate electron fluids. It is observed that there is a Mach-speed gap in which no large amplitude localized or periodic nonlinear excitations can propagate in the plasma under consideration. It is further revealed that the plasma under investigation supports propagation of double-wells and double-layers the chemical potential and Mach number ranges of which are studied in terms of other plasma parameters. The Mach number criteria for nonlinear waves are shown to significantly differ for cases of classical with η0 < 0 and quantum with η0 > 0 regimes. It is also shown that the localized structure propagation criteria possess significant dissimilarities for plasmas with adiabatic and isothermal ions. Current research may be generalized to study the nonlinear structures in plasma containing positrons, multiple ions with different charge states, and charged dust grains.

  16. Double Planet Meets Triple Star

    NASA Astrophysics Data System (ADS)

    2002-08-01

    High-Resolution VLT Image of Pluto Event on July 20, 2002 A rare celestial phenomenon involving the distant planet Pluto has occurred twice within the past month. Seen from the Earth, this planet moved in front of two different stars on July 20 and August 21, respectively, providing observers at various observatories in South America and in the Pacific area with a long awaited and most welcome opportunity to learn more about the tenuous atmosphere of that cold planet. On the first date, a series of very sharp images of a small sky field with Pluto and the star was obtained with the NAOS-CONICA (NACO) adaptive optics (AO) camera mounted on the ESO VLT 8.2-m YEPUN telescope at the Paranal Observatory. With a diameter of about 2300 km, Pluto is about six times smaller than the Earth. Like our own planet, it possesses a relatively large moon, Charon , measuring 1200 km across and circling Pluto at a distance of about 19,600 km once every 6.4 days. In fact, because of the similarity of the two bodies, the Pluto-Charon system is often referred to as a double planet . At the current distance of nearly 4,500 million km from the Earth, Pluto's disk subtends a very small angle in the sky, 0.107 arcsec. It is therefore very seldom that Pluto - during its orbital motion - passes exactly in front of a comparatively bright star. Such events are known as "occultations" , and it is difficult to predict exactly when and where on the Earth's surface they are visible. Stellar occultations When Pluto moves in front of a star, it casts a "shadow" on the Earth's surface within which an observer cannot see the star, much like the Earth's Moon hides the Sun during a total solar eclipse. During the occultation event, Pluto's "shadow" also moves across the Earth's surface. The width of this shadow is equal to Pluto's diameter, i.e. about 2300 km. One such occultation event was observed in 1988, and two others were expected to occur in 2002, according to predictions published in 2000 by

  17. Monocular Elevation Deficiency - Double Elevator Palsy

    MedlinePlus

    ... Eye Terms Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Monocular Elevation Deficiency/ Double Elevator Palsy En Español Read in Chinese What is monocular elevation deficiency (Double Elevator Palsy)? ...

  18. Monocular Elevation Deficiency - Double Elevator Palsy

    MedlinePlus

    ... Español Condiciones Chinese Conditions Monocular Elevation Deficiency/ Double Elevator Palsy En Español Read in Chinese What is monocular elevation deficiency (Double Elevator Palsy)? Monocular Elevation Deficiency, also known by the ...

  19. Bifurcation structure of successive torus doubling

    NASA Astrophysics Data System (ADS)

    Sekikawa, Munehisa; Inaba, Naohiko; Yoshinaga, Tetsuya; Tsubouchi, Takashi

    2006-01-01

    The authors discuss the “embryology” of successive torus doubling via the bifurcation theory, and assert that the coupled map of a logistic map and a circle map has a structure capable of generating infinite number of torus doublings.

  20. Five-photon double ionization of helium

    NASA Astrophysics Data System (ADS)

    Li, Y.; Pindzola, M. S.; Colgan, J.

    2016-03-01

    A time-dependent close-coupling method is used to calculate the five-photon double ionization of He. It is found that the generalized cross section used in the past for two-photon double ionization of He cannot be extended to five-photon double ionization of He. Therefore only five-photon double ionization probabilities that depend on specific radiation field pulses can be calculated.

  1. Minimal Doubling and Point Splitting

    SciTech Connect

    Creutz, M.

    2010-06-14

    Minimally-doubled chiral fermions have the unusual property of a single local field creating two fermionic species. Spreading the field over hypercubes allows construction of combinations that isolate specific modes. Combining these fields into bilinears produces meson fields of specific quantum numbers. Minimally-doubled fermion actions present the possibility of fast simulations while maintaining one exact chiral symmetry. They do, however, introduce some peculiar aspects. An explicit breaking of hyper-cubic symmetry allows additional counter-terms to appear in the renormalization. While a single field creates two different species, spreading this field over nearby sites allows isolation of specific states and the construction of physical meson operators. Finally, lattice artifacts break isospin and give two of the three pseudoscalar mesons an additional contribution to their mass. Depending on the sign of this mass splitting, one can either have a traditional Goldstone pseudoscalar meson or a parity breaking Aoki-like phase.

  2. Double Lambda and Xi hypernuclei

    NASA Astrophysics Data System (ADS)

    Nakazawa, Kazuma

    2014-09-01

    Nuclei with double strangeness (S = -2) provide the key information to understand Baryon-Baryon interaction under the SU(3)f symmetry. Therefore we have carried out the experiments at KEK for quarter a century. Recently, the interaction in S = -2 sector is noted to derive the information of the EOS of neutron star. The Lambda-Lambda interaction has been presented to be weak attractive by NAGARA event which showed the production and decay of 6He double-hypernucleus. The event also presented the lower mass limit of H dibaryon. In other five events, we obtained the knowledge about an excitation level of 10Be double-hypernucleus under the consistency with NAGARA event. Moreover, very recently, we have discovered a Xi-14N system which was deeply bound far from the atomic 3D level (0.17 MeV) for a captured Xi hyperon. Since a 8Li nucleus was associated with the decay of one of twin-hypernuclei, the event was uniquely identified as Xi- + 14N ==> 10BeL + 5HeL. The system was selected from 8 million pictures on the test running for development of ``Overall Scanning'' to be used in the coming experiment. This is the first evidence of Xi hypernucleus to be bound and it is impacting for the study of Xi-N interaction. At J-PARC facility, for the further study of hyperon-hyperon interaction, we plan to perform the E07 experiment at J-PARC. In the workshop, we will review the above knowledge obtained by the experiments at KEK-PS, and discuss developed technologies to detected 102 or more double-hypernuclei in the E07 experiment at J-PARC. Nuclei with double strangeness (S = -2) provide the key information to understand Baryon-Baryon interaction under the SU(3)f symmetry. Therefore we have carried out the experiments at KEK for quarter a century. Recently, the interaction in S = -2 sector is noted to derive the information of the EOS of neutron star. The Lambda-Lambda interaction has been presented to be weak attractive by NAGARA event which showed the production and decay of 6He

  3. Hierarchy in a double braneworld

    SciTech Connect

    Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra; Pantoja, Nelson

    2006-10-15

    We show that the hierarchy between the Planck and the weak scales can follow from the tendency of gravitons and fermions to localize at different edges of a thick double wall embedded in an AdS{sub 5} spacetime without reflection symmetry. This double wall is a stable BPS thick-wall solution with two subwalls located at its edges; fermions are coupled to the scalar field through Yukawa interactions, but the lack of reflection symmetry forces them to be localized in one of the subwalls. We show that the graviton zero-mode wave function is suppressed in the fermion edge by an exponential function of the distance between the subwalls, and that the massive modes decouple so that Newtonian gravity is recuperated.

  4. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-01-01

    Post-16 Initiative logo This is the first of a regular series of contributions from the Institute's Post-16 Initiative. The Initiative is taking a hard and searching look at the physics taught in schools and colleges from age 16 to age 19. To start with, it is responding to Government initiatives, but hopes to encourage and stimulate good practice in physics teaching on a longer time scale than can be afforded in making responses to current developments. Here Jon Ogborn writes about what AS courses need to be, while Peter Campbell gives his thoughts about teaching matter. Advanced Subsidiary physics: what should it be? From September 2000 all A-levels will be new. Students can take the first Advanced Subsidiary (AS) year and stop there - or decide to go on. In the Institute of Physics post-16 Initiative, we have been thinking how to provide a satisfying one-year experience of physics at the new AS level, and what it should achieve. The students will decide. So the AS course must give a decent picture of what physics is, what it offers for their futures, what interests it can satisfy. That all says breadth, with enough depth to see what is in store later. And this sounds like the right recipe for someone who is taking a single AS year of physics to broaden their A-level experience. It must also be attractive. A way forward is shown by the Salters - Horners course, attracting interest through leading from applications. Why does that work? It gives physics a story to tell, into which ideas fit and make sense. Our own new A-level, Advancing Physics, must also have interesting stories to tell, which must in addition build up an honest picture of physics. An example: teach electric circuits through modern sensing devices. Sensor instrumentation is a key activity of physicists, full of new ideas, but also simple. It makes essential use of circuits such as the potential divider. Practical work gets better things to do than checking the equation for resistors in parallel

  5. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-07-01

    (post16) Faces of Physics To study a physics course post-16 is take out an option on your future. But physics itself is very varied, and so is what you might do with it. It seems right that post-16 physics courses reflect important aspects of this variety. Physics varies with why people do it. As reliable knowledge, physics is often essential to making things happen. This is physics as feeding into technology, and quite often feeding off technology. The human urge here is the urge to create things that work. It drives individual inventors; it drives large teams in multinational companies. At the opposite end of this spectrum is physics driven by curiosity, by the urge to find out. The stock examples are the grand discoveries from the expansion of the universe to the discovery of the nucleus of atoms. But the physicist's curiosity is often on a more detailed, even finicky scale: how exactly do the molecules of this polymer respond to stress?; just how do ions implanted in this material modify its conductivity? It is clear to me that a decent post-16 physics course must respect and reflect both. This is by no means a matter of `basic laws and their applications'. It is a matter of recognizing two fundamental interests, in doing and in explaining, and of recognizing that they are at once closely interdependent and worlds apart. Ideas in physics are also not of one kind. One opposition is the idea of describing Nature in terms of deterministic physical laws, as against describing Nature as the predictable outcome of probabilistic behaviour `underneath'. The first has gripped the Western imagination since at least the time of Descartes. The second has increasingly come to the fore, especially in thermodynamics with the idea that we can only make processes work by fixing the circumstances so that uncaring atoms and molecules happen by chance to do what we want. Now in quantum theory both ideas - determinism and randomness - co-exist. Post-16 physics courses are not in

  6. Double Chooz and recent results

    NASA Astrophysics Data System (ADS)

    Meregaglia, A.; Double Chooz Collaboration

    2016-07-01

    The reactor bar{{ν}}e^{} disappearance experiment Double Chooz, located in France near the power plant of Chooz, has as main goal the measurement of the θ_{{13}}^{} mixing angle. For the first time, in 2011, the experimental results gave an indication for a non-zero value of such an oscillation parameter. The mixing angle was successively measured using only the far detector finding the best fit value of sin2(2 θ_{{13}}^{}) = 0.090+0.033-0.029 . The near detector started data taking in December 2014 and it will allow to reduce the systematic errors so far dominated by the reactor flux uncertainty. In this paper a review of the experiment is presented focusing on the so-called Gadolinium-III results (DOUBLE CHOOZ COLLABORATION (ABE Y. et al.), JHEP, 10 (2014) 086; 02 (2015) 074). Furthermore additional physics measurements are presented such as the capability of Double Chooz to identify the ortho-positronium state on event by event basis.

  7. Pair extended coupled cluster doubles

    SciTech Connect

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  8. Revisiting double Dirac delta potential

    NASA Astrophysics Data System (ADS)

    Ahmed, Zafar; Kumar, Sachin; Sharma, Mayank; Sharma, Vibhu

    2016-07-01

    We study a general double Dirac delta potential to show that this is the simplest yet still versatile solvable potential to introduce double wells, avoided crossings, resonances and perfect transmission (T = 1). Perfect transmission energies turn out to be the critical property of symmetric and anti-symmetric cases wherein these discrete energies are found to correspond to the eigenvalues of a Dirac delta potential placed symmetrically between two rigid walls. For well(s) or barrier(s), perfect transmission (or zero reflectivity, R(E)) at energy E=0 is non-intuitive. However, this has been found earlier and called the ‘threshold anomaly’. Here we show that it is a critical phenomenon and we can have 0≤slant R(0)\\lt 1 when the parameters of the double delta potential satisfy an interesting condition. We also invoke a zero-energy and zero curvature eigenstate (\\psi (x)={Ax}+B) of the delta well between two symmetric rigid walls for R(0)=0. We resolve that the resonant energies and the perfect transmission energies are different and they arise differently.

  9. 46 CFR 171.105 - Double bottoms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Double bottoms. 171.105 Section 171.105 Shipping COAST... VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.105 Double bottoms. (a) This section... over 165 feet (50 meters) and under 200 feet (61 meters) in LBP must have a double bottom that...

  10. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to... United States entered under this section, the Attorney General may recover double the value of the...

  11. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to... United States entered under this section, the Attorney General may recover double the value of the...

  12. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to... United States entered under this section, the Attorney General may recover double the value of the...

  13. 46 CFR 171.105 - Double bottoms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Double bottoms. 171.105 Section 171.105 Shipping COAST... VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.105 Double bottoms. (a) This section... over 165 feet (50 meters) and under 200 feet (61 meters) in LBP must have a double bottom that...

  14. 46 CFR 171.105 - Double bottoms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Double bottoms. 171.105 Section 171.105 Shipping COAST... VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.105 Double bottoms. (a) This section... over 165 feet (50 meters) and under 200 feet (61 meters) in LBP must have a double bottom that...

  15. 46 CFR 171.105 - Double bottoms.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Double bottoms. 171.105 Section 171.105 Shipping COAST... VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.105 Double bottoms. (a) This section... over 165 feet (50 meters) and under 200 feet (61 meters) in LBP must have a double bottom that...

  16. 46 CFR 171.105 - Double bottoms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Double bottoms. 171.105 Section 171.105 Shipping COAST... VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.105 Double bottoms. (a) This section... over 165 feet (50 meters) and under 200 feet (61 meters) in LBP must have a double bottom that...

  17. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to... United States entered under this section, the Attorney General may recover double the value of the...

  18. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to... United States entered under this section, the Attorney General may recover double the value of the...

  19. The Assessment of Post-Traumatic Stress Disorder among Minority Vietnam Veterans.

    ERIC Educational Resources Information Center

    LaDue, Robin A.

    Vietnam veterans from racial or ethnic minority groups have a "double minority" status; clinicians treating these veterans should distinguish between behaviors resulting from experiences in Vietnam and those due to experiences as members of minority groups. Post-Traumatic Stress Disorder (PTSD) affects an estimated 20% of all Vietnam veterans and…

  20. NEWS: Post-16 update

    NASA Astrophysics Data System (ADS)

    Campbell, Peter

    2000-07-01

    post16.gif As a teacher of physics it is very easy to become preoccupied with particulars of courses, or topics or even single concepts. Concerned with imminent student audiences and desired learning outcomes, the daily challenge is to summon satisfactory teaching approaches and resources for the job at hand. For the conscientious teacher, assessment outcomes may too often seem a judgment on our own efforts rather than those of our students. From time to time we may step back and think bigger, for example while planning a recruitment event, or while away from work on holiday. We may be successful locally. But why, at a time when books and television documentaries popularizing science have a large following, has physics education been facing declining numbers? Many recognize that physics has an essential contribution to make to the training of science or engineering specialists, but we know that it is also important for the skilled worker, the informed citizen and, in fact, for anyone trying to make sense of the world. So what are the best ways forward for post-16 physics? To make any impact on the bigger picture requires organization, thinking and meeting time among people in diverse roles: teachers and curriculum managers; university lecturers; employers and professional bodies; unitary awarding bodies; regulatory and funding agencies; and even Government. For the past few years, the Institute of Physics post-16 Initiative has created an unrivalled opportunity to address the wider issues. Its Shaping the Future booklets series was designed to stimulate informed discussion and debate, by providing background information and analysis. Taken together, the booklets should help all those concerned with physics education to understand where we are now, and why. Literally dozens of people have contributed to a review and analysis of physics education. Each booklet is a 48-page smorgasbord in A4 landscape format, containing many examples of good practice, basic but

  1. IVGEN Post Flight Analysis

    NASA Technical Reports Server (NTRS)

    Mcquillen, John; Brown, Dan; Hussey, Sam; Zoldak, John

    2014-01-01

    The Intravenous Fluid Generation (IVGEN) Experiment was a technology demonstration experiment that purified ISS potable water, mixed it with salt, and transferred it through a sterilizing filter. On-orbit performance was verified as appropriate and two 1.5 l bags of normal saline solution were returned to earth for post-flight testing by a FDA certified laboratory for compliance with United States Pharmacopiea (USP) standards. Salt concentration deviated from required values and an analysis identified probable causes. Current efforts are focused on Total Organic Content (TOC) testing, and shelf life.The Intravenous Fluid Generation (IVGEN) Experiment demonstrated the purification of ISS potable water, the mixing of the purified water with sodium chloride, and sterilization of the solution via membrane filtration. On-orbit performance was monitored where feasible and two 1.5-liter bags of normal saline solution were returned to earth for post-flight testing by a FDA-registered laboratory for compliance with United States Pharmacopeia (USP)standards [1]. Current efforts have been focused on challenge testing with identified [2] impurities (total organic-carbon), and shelf life testing. The challenge testing flowed known concentrations of contaminants through the IVGEN deionizing cartridge and membrane filters to test their effectiveness. One finding was that the filters and DI-resin themselves contribute to the contaminant load during initial startup, suggesting that the first 100 ml of fluid be discarded. Shelf life testing is ongoing and involves periodic testing of stored DI cartridges and membrane filters that are capped and sealed in hermetic packages. The testing is conducted at six month intervals measuring conductivity and endotoxins in the effluent. Currently, the packaging technique has been successfully demonstrated for one year of storage testing. The USP standards specifies that the TOC be conducted at point of generation as opposed to point of

  2. NEWS: Post-16 update

    NASA Astrophysics Data System (ADS)

    Campbell, Peter

    2000-07-01

    post16.gif As a teacher of physics it is very easy to become preoccupied with particulars of courses, or topics or even single concepts. Concerned with imminent student audiences and desired learning outcomes, the daily challenge is to summon satisfactory teaching approaches and resources for the job at hand. For the conscientious teacher, assessment outcomes may too often seem a judgment on our own efforts rather than those of our students. From time to time we may step back and think bigger, for example while planning a recruitment event, or while away from work on holiday. We may be successful locally. But why, at a time when books and television documentaries popularizing science have a large following, has physics education been facing declining numbers? Many recognize that physics has an essential contribution to make to the training of science or engineering specialists, but we know that it is also important for the skilled worker, the informed citizen and, in fact, for anyone trying to make sense of the world. So what are the best ways forward for post-16 physics? To make any impact on the bigger picture requires organization, thinking and meeting time among people in diverse roles: teachers and curriculum managers; university lecturers; employers and professional bodies; unitary awarding bodies; regulatory and funding agencies; and even Government. For the past few years, the Institute of Physics post-16 Initiative has created an unrivalled opportunity to address the wider issues. Its Shaping the Future booklets series was designed to stimulate informed discussion and debate, by providing background information and analysis. Taken together, the booklets should help all those concerned with physics education to understand where we are now, and why. Literally dozens of people have contributed to a review and analysis of physics education. Each booklet is a 48-page smorgasbord in A4 landscape format, containing many examples of good practice, basic but

  3. Nuclear Power - Post Fukushima

    NASA Astrophysics Data System (ADS)

    Reyes, Jose, Jr.

    2011-10-01

    The extreme events that led to the prolonged power outage at the Fukushima Daiicchi nuclear plant have highlighted the importance of assuring a means for stable long term cooling of the nuclear fuel and containment following a complete station blackout. Legislative bodies, regulatory agencies and industry are drawing lessons from those events and considering what changes, if any, are needed to nuclear power, post Fukushima. The enhanced safety of a new class of reactor designed by NuScale Power is drawing significant attention in light of the Fukushima events. During normal operation, each NuScale containment is fully immersed in a water-filled stainless steel lined concrete pool that resides underground. The pool, housed in a Seismic Category I building, is large enough to provided 30 days of core and containment cooling without adding water. After 30 days, the decay heat generations coupled with thermal radiation heat transfer is completely adequate to remove core decay heat for an unlimited period of time. These passive power systems can perform their function without requiring an external supply of water of power. An assessment of the NuScale passive systems is being performed through a comprehensive test program that includes the NuScale integral system test facility at Oregon State University

  4. Redefining Post-Secondary Education

    ERIC Educational Resources Information Center

    Turpin, David H.

    2005-01-01

    For at least a brief period of time, the release of Bob Rae's review of post-secondary education in Ontario served to focus public attention on the importance of post-secondary education not only in Ontario, but across Canada. This article elaborates further on Rae's review which stresses the crucial importance of the higher studies and recommends…

  5. Post-16 Science in England

    ERIC Educational Resources Information Center

    Swinscoe, David

    2012-01-01

    Science education at post-16 has had a high profile recently. Increasing the quality and quantity of STEM education is seen as a route to economic prosperity for both the individual and the nation. The post-16 sector is being encouraged to produce more STEM undergraduates and more STEM-skilled entrants to the industry with an emphasis on…

  6. Simulation of plasma double-layer structures

    NASA Technical Reports Server (NTRS)

    Borovsky, J. E.; Joyce, G.

    1982-01-01

    Electrostatic plasma double layers are numerically simulated by means of a magnetized 2 1/2 dimensional particle in cell method. The investigation of planar double layers indicates that these one dimensional potential structures are susceptible to periodic disruption by instabilities in the low potential plasmas. Only a slight increase in the double layer thickness with an increase in its obliqueness to the magnetic field is observed. Weak magnetization results in the double layer electric field alignment of accelerated particles and strong magnetization results in their magnetic field alignment. The numerical simulations of spatially periodic two dimensional double layers also exhibit cyclical instability. A morphological invariance in two dimensional double layers with respect to the degree of magnetization implies that the potential structures scale with Debye lengths rather than with gyroradii. Electron beam excited electrostatic electron cyclotron waves and (ion beam driven) solitary waves are present in the plasmas adjacent to the double layers.

  7. NEWS: Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-05-01

    (post16) Making physics connect Doesn't Melvyn Bragg do a wonderful job, engaging both scientists and artists in sensitive discussion on Radio 4 about their methods and their purposes? But every week teachers have the chance to show their students that physics is a way of seeing the world that is well-connected with other aspects of knowledge and culture. The stakes are high: students who fail to appreciate this generally choose not to study the subject beyond GCSE. Most students find our preoccupation with technical detail off-putting. Accepting that we have a syllabus to cover, it's still a question of balance. In our teaching we should aim for variety in order to find ways to connect with every student's interests. Also, we can show that we (the nearest embodiment of a physicist some students will experience) are multidimensional and so fully human. Most important, teachers need flexibility to both encourage and respond to student comment and questions. The first booklet in the discussion series Shaping the Future takes up these themes. Rich in ideas for both immediate use and the longer term, it aims to stimulate debate and improve teaching. Copies cost £5.50 including postage and are available from Ingrid Ebeyer, Post-16 Initiative, Institute of Physics, 76 Portland Place, London W1N 3DH. How far is it? This question is asked in many family cars and school minibuses at the start of a journey, and answered by most in terms of hours and minutes rather than miles. What a good idea for introducing a social and historical perspective to a lesson on distance, velocity and time. How far can you actually get in a day? What is the range of human activity? Walking for eight hours will get many people about 25 miles. A pack horse will progress at much the same rate, but fast riding or a coach and team of horses will get further. Motorway driving (when the cones are on holiday) would take you nearly 500 miles. The 05.15 am train from Penzance arrives in Inverness at 7

  8. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-11-01

    (Post-16 Initiative) Engineering Physics? Many A-level physics students do not go on to study physics. For them physics is a support subject, either just for fun or just for the grade. Where physics is a lead subject some students go on to study physics but many more go on to study engineering. So can we deliberately give some aspects of an A-level course an engineering flavour? Electromagnetism would seem a good place to start. There is a clear `physics' route into this topic, a microscopic forces and fields view of the situation. But do our students really need to look at it this way? All electromagnetic machines are linked magnetic and electric circuits. The design idea is to link these circuits as closely as possible. The electric circuits must be as good as possible, with a high conductivity. The magnetic circuits must be as good as possible, with high permeance. Conductivity depends on area/length. So does permeance. The goodness of an electromagnetic machine (how good it is at its job, which is linking electric and magnetic circuits) scales as the square of its linear dimensions. That means small electromagnetic machines are harder to make, and so the very smallest nanomotors are electrostatic. None of this is new, but many teachers are uncomfortable with it. We are thinking like physicists. Many of our students are not. They deserve us to take the trouble every now and again to encourage them to think a bit differently about a topic, to look at practical ways of discussing design and to give their course an engineering flavour. Philip Britton Coursework in A-level Physics The criteria for the new AS and A-levels have provided the teams developing the specifications with an opportunity to think creatively about how internal assessment is used within post-16 physics courses. Teachers may be concerned that allowing 30% of the marks to be internally assessed will create a burden for them. However, it is possible to look at this in a much more positive light

  9. Post-herpetic neuralgia

    PubMed Central

    Tontodonati, Monica; Ursini, Tamara; Polilli, Ennio; Vadini, Francesco; Di Masi, Francesco; Volpone, Damiano; Parruti, Giustino

    2012-01-01

    Background In spite of the large body of evidence available in the literature, definition and treatment of Post-Herpetic Neuralgia (PHN) are still lacking a consistent and universally recognized standardization. Furthermore, many issues concerning diagnosis, prediction and prevention of PHN need to be clarified in view of recent contributions. Objectives To assess whether PHN may be better defined, predicted, treated and prevented in light of recent data, and whether available alternative or adjunctive therapies may improve pain relief in treatment recalcitrant PHN. Methods Systematic reviews, meta-analyses, randomized controlled trials, cohort studies and protocols were searched; the search sources included PubMed, Cochrane Library, NICE, and DARE. More than 130 papers were selected and evaluated. Results Diagnosis of PHN is essentially clinical, but it can be improved by resorting to the many tools available, including some practical and accessible questionnaires. Prediction of PHN can be now much more accurate, taking into consideration a few well validated clinical and anamnestic variables. Treatment of PHN is presently based on a well characterized array of drugs and drug associations, including, among others, tricyclic antidepressants, gabapentinoids, opioids and many topical formulations. It is still unsatisfactory, however, in a substantial proportion of patients, especially those with many comorbidities and intense pain at herpes zoster (HZ) presentation, so that this frequent complication of HZ still strongly impacts on the quality of life of affected patients. Conclusion Further efforts are needed to improve the management of PHN. Potentially relevant interventions may include early antiviral therapy of acute HZ, prevention of HZ by adult vaccination, as well as new therapeutic approaches for patients experiencing PHN. PMID:23109810

  10. Booster double harmonic setup notes

    SciTech Connect

    Gardner, C. J.

    2015-02-17

    The motivation behind implementing a booster double harmonic include the reduced transverse space charge force from a reduced peak beam current and reduced momentum spread of the beam, both of which can be achieved from flattening the RF bucket. RF capture and acceleration of polarized protons (PP) is first set up in the single harmonic mode with RF harmonic h=1. Once capture and acceleration have been set up in the single harmonic mode, the second harmonic system is brought on and programmed to operate in concert with the single harmonic system.

  11. AGI doubles minority geoscience scholarships

    NASA Astrophysics Data System (ADS)

    The American Geological Institute, Alexandria, Va., has had a significant increase in funds available for minority geoscience scholarships for the 1990-1991 academic year. The number of scholarships awarded this year has more than doubled from a total of 36 in 1989-90 to 80 available for 1990-1991.The increase is due largely to a grant from the National Science Foundation. Total value of the awards, which will be given to undergraduate and graduate geoscience students, will be $221,000. For 1989--990 the total value was $36,750.

  12. Semiconductor double quantum dot micromaser.

    PubMed

    Liu, Y-Y; Stehlik, J; Eichler, C; Gullans, M J; Taylor, J M; Petta, J R

    2015-01-16

    The coherent generation of light, from masers to lasers, relies upon the specific structure of the individual emitters that lead to gain. Devices operating as lasers in the few-emitter limit provide opportunities for understanding quantum coherent phenomena, from terahertz sources to quantum communication. Here we demonstrate a maser that is driven by single-electron tunneling events. Semiconductor double quantum dots (DQDs) serve as a gain medium and are placed inside a high-quality factor microwave cavity. We verify maser action by comparing the statistics of the emitted microwave field above and below the maser threshold. PMID:25593187

  13. Double window viewing chamber assembly

    NASA Technical Reports Server (NTRS)

    Keller, V. W. (Inventor); Owen, R. B. (Inventor); Elkins, B. R. (Inventor); White, W. T. (Inventor)

    1986-01-01

    A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter.

  14. Nonsequential double ionization of molecules

    SciTech Connect

    Prauzner-Bechcicki, Jakub S.; Sacha, Krzysztof; Zakrzewski, Jakub; Eckhardt, Bruno

    2005-03-01

    Double ionization of diatomic molecules by short linearly polarized laser pulses is analyzed. We consider the final stage of the ionization process, that is the decay of a highly excited two electron molecule, which is formed after rescattering. The saddles of the effective adiabatic potential energy close to which simultaneous escape of electrons takes place are identified. Numerical simulations of the ionization of molecules show that the process can be dominated by either sequential or nonsequential events. In order to increase the ratio of nonsequential to sequential ionizations very short laser pulses should be applied.

  15. Reviewing Canadian Post-Secondary Education: Post-Secondary Education Policy in Post-Industrial Canada

    ERIC Educational Resources Information Center

    Kirby, Dale

    2007-01-01

    Since 2004, a number of Canadian provinces have initiated comprehensive reviews of their respective public post-secondary education systems. This paper examines the ways in which these provincial post-secondary education reviews are consistent with the pervasive influence of economic globalization on higher education and a more market-driven and…

  16. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-03-01

    Post-16 Initiative logo Physics in Mathematical Mood Later this year, as part of the post-16 initiative of the Institute of Physics, a booklet with the above title will be published. In draft form, the booklet was discussed at the ASE conference in January. Some of the issues raised are briefly set out here. If you have any views to contribute, please write to Simon Carson at the Institute of Physics or e-mail simon.carson@physics.org. A mathematical view of the world is intrinsically a part of physics and therefore physics should be studied in an appropriately mathematical way. However, we all know that, to some students at least, mathematics proves to be a stumbling block rather than a powerful aid to understanding. So how can we help? Realizing that as physics teachers we need to deliver the mathematics necessary to an understanding of our subject is a start. Its corollary is that we need to find the space within the physics core. We may wish to use supplementary courses such as AS mathematics or QCA's new free-standing mathematics units, but requiring additional courses as a prerequisite to a study of A-level physics may deter students. Teaching the mathematics in context may aid understanding but we also must ensure that techniques are seen in a variety of contexts and that at some point the tool is abstracted from the background. As teachers we need to be aware of the very basic mathematical difficulties that students bring with them: the use of calculators, standard form, simple algebraic manipulation, for example. Mathematical arguments need to be developed fully and carefully. Encouraging cooperation and discussion between students may help the less able to understand and the more able to appreciate and develop their own understanding through making explicit their reasoning by explaining it to others. And what of new technology? Software tools allow students to develop their understanding about graphs, for example, enabling them to investigate the

  17. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, Hannes

    1986-01-01

    As the rate of energy release in a double layer with voltage delta V is P approx I delta V, a double layer must be treated as a part of a circuit which delivers the current I. As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by means of double layers. They must be replaced by particle models and circuit theory. A simple circuit is suggested which is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object (one example is the double radio sources). It is tentatively suggested in X-ray and Gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). A study of how a number of the most used textbooks in astrophysics treat important concepts like double layers, critical velocity, pinch effects and circuits is made.

  18. 75 FR 4039 - Proposed Posting, Posting, and Deposting of Stockyards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... the Federal Register (74 FR 17945-17947) of our proposal to post these 20 stockyards. Since we... location CA-193 Westside Auction Yard, Newman, California. AZ-117 Robertson Horse Sales, Benson,...

  19. Double Chooz Slow Monitoring System

    NASA Astrophysics Data System (ADS)

    Chang, Pi-Jung; Horton-Smith, Glenn; McKee, David; Shrestha, Deepak; Winslow, Lindley; Conrad, Janet

    2010-02-01

    The Double Chooz experiment aims to measure neutrino flux from two nearly identical detectors with an uncertainty less than 0.6%. The Double Chooz slow monitoring system records conditions of the experiment's environment which can impact the experiment's goals. The slow monitoring system includes temperatures and voltages in electronics, experimental hall environmental conditions, line voltages, liquid temperatures, PMT's magnetic field, radon concentrations, and photo-tube high voltages. This system scans all channels automatically, stores data in a common database, and warns of changes in the two detectors' physical environments. Most functions in this system can be accomplished by 1-Wire products from Dallas Semiconductor. We can use a single master for several functions' controls and operations and the power is derived from a signal bus. Every device has a unique unalterable ID. The sensors monitoring the liquid system, such as liquid thermal meters, are covered by epoxy in order to isolate in the liquid. Their radioactivity can be ignored and will not affect the uncertainty in the system. )

  20. Infinite sets and double binds.

    PubMed

    Arden, M

    1984-01-01

    There have been many attempts to bring psychoanalytical theory up to date. This paper approaches the problem by discussing the work of Gregory Bateson and Ignacio Matte-Blanco, with particular reference to the use made by these authors of Russell's theory of logical types. Bateson's theory of the double bind and Matte-Blanco's bilogic are both based on concepts of logical typing. It is argued that the two theories can be linked by the idea that neurotic symptoms are based on category errors in thinking. Clinical material is presented from the analysis of a middle-aged woman. The intention is to demonstrate that the process of making interpretations can be thought of as revealing errors in thinking. Changes in the patient's inner world are then seen to be the result of clarifying childhood experiences based on category errors. Matte-Blanco's theory of bilogic and infinite experiences is a re-evaluation of the place of the primary process in mental life. It is suggested that a combination of bilogic and double bind theory provides a possibility of reformulating psychoanalytical theory. PMID:6544755

  1. Double-Front Detonation Waves

    NASA Astrophysics Data System (ADS)

    Gubin, S. A.; Sumskoi, S. I.; Victorov, S. B.

    According to the theory of detonation, in a detonation wave there is a sound plane, named Chapman-Jouguet (CJ) plane. There are certain stationary parameters for this plane. In this work the possibility of the second CJ plane is shown. This second CJ plane is stationary as well. The physical mechanism of non-equilibrium transition providing the existence of the second CJ plane is presented. There is a non-equilibrium state, when the heat is removed from the reaction zone and the heat capacity decreases sharply. As a result of this non-equilibrium state, the sound velocity increases, and the local supersonic zone with second sonic plane (second CJ plane) appears. So the new mode of detonation wave is predicted. Equations describing this mode of detonation are presented. The exact analytical solution for the second CJ plane parameters is obtained. The example of double-front detonation in high explosive (TNT) is presented. In this double-front structure "nanodiamond-nanographite" phase transition takes place in condensed particles of detonation products.

  2. Double distributions and evolution equations

    SciTech Connect

    A.V. Radyushkin

    1998-05-01

    Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements < p{prime} {vert_bar}O(0,z){vert_bar}p > of quark and gluon light-cone operators. In their previous papers the authors used two types of nonperturbative functions parameterizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F{sub {zeta}}(X;t). Here they discuss in more detail the double distributions (DD's) and evolution equations which they satisfy. They propose simple models for F(x,y;t=0) DD's with correct spectral and symmetry properties which also satisfy the reduction relations connecting them to the usual parton densities f(x). In this way, they obtain self-consistent models for the {zeta}-dependence of nonforward distributions. They show that, for small {zeta}, one can easily obtain nonforward distributions (in the X > {zeta} region) from the parton densities: F{sub {zeta}} (X;t=0) {approx} f(X{minus}{zeta}/2).

  3. Double-diffusive layer formation

    NASA Astrophysics Data System (ADS)

    Zaussinger, Florian; Kupka, Friedrich; Hücker, Sebastian; Egbers, Christoph

    2015-04-01

    Double-diffusive convection plays an important role in geo- and astrophysical applications. The special case, where a destabilising temperature gradient counteracts a stabilising solute gradient leads to layering phenomena under certain conditions. Convectively mixed layers sandwiched in diffusive interfaces form a so-called stack. Well-known double-diffusive systems are observed in rift lakes in Africa and even from the coffee drink Latte Macciatto. Stacks of layers are also predicted to occur inside massive stars and inside giant planets. Their dynamics depend on the thermal, the solute and the momentum diffusivities, as well on the ratio of the gradients of the opposing stratifications. Since the layering process cannot be derived from linear stability analysis, the full nonlinear set of equations has to be investigated. Numerical simulations have become feasible for this task, despite the physical processes operate on a vast range of length and time scales, which is challenging for numerical hydrodynamical modelling. The oceanographically relevant case of fresh and salty water is investigated here in further details. The heat and mass transfer is compared with theoretical results and experimental measurements. Additionally, the initial dynamic of layering, the transient behaviour of a stack and the long time evolution are presented using the example of Lake Kivu and the interior of a giant planet.

  4. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-03-01

    Post-16 Initiative logo Physics in Mathematical Mood Later this year, as part of the post-16 initiative of the Institute of Physics, a booklet with the above title will be published. In draft form, the booklet was discussed at the ASE conference in January. Some of the issues raised are briefly set out here. If you have any views to contribute, please write to Simon Carson at the Institute of Physics or e-mail simon.carson@physics.org. A mathematical view of the world is intrinsically a part of physics and therefore physics should be studied in an appropriately mathematical way. However, we all know that, to some students at least, mathematics proves to be a stumbling block rather than a powerful aid to understanding. So how can we help? Realizing that as physics teachers we need to deliver the mathematics necessary to an understanding of our subject is a start. Its corollary is that we need to find the space within the physics core. We may wish to use supplementary courses such as AS mathematics or QCA's new free-standing mathematics units, but requiring additional courses as a prerequisite to a study of A-level physics may deter students. Teaching the mathematics in context may aid understanding but we also must ensure that techniques are seen in a variety of contexts and that at some point the tool is abstracted from the background. As teachers we need to be aware of the very basic mathematical difficulties that students bring with them: the use of calculators, standard form, simple algebraic manipulation, for example. Mathematical arguments need to be developed fully and carefully. Encouraging cooperation and discussion between students may help the less able to understand and the more able to appreciate and develop their own understanding through making explicit their reasoning by explaining it to others. And what of new technology? Software tools allow students to develop their understanding about graphs, for example, enabling them to investigate the

  5. Simple Arm Tourniquet as an Adjunct to Double-Cuff Tourniquet in Intravenous Regional Anesthesia

    PubMed Central

    Jafarian, Ali Akbar; Imani, Farnad; Salehi, Reza; Najd Mazaher, Farid; Moini, Fatemeh

    2016-01-01

    Background: Intravenous Regional Anesthesia (IVRA) is a well-known technique for producing analgesia during surgical procedures in the extremities. However, the rapid onset of pain following the deflation of a double-cuff tourniquet during IVRA is a serious disadvantage, leading patient suffering. Objectives: The aim of this study was to evaluate the clinical effectiveness of a pneumatic arm tourniquet applied 2 cm above the double-cuff tourniquet in controlling the pain that occurs after its deflation. Patients and Methods: Twenty patients undergoing outpatient hand surgery were operated on under IVRA, using 40 - 50 mL of a solution containing 3 mg/kg of lignocaine. A simple pneumatic tourniquet was applied proximal to the double-cuff tourniquet, 3 min before its deflation, while the procedure was being conducted. The severity of pain on the basis of the Numerical Rating Scale (NRS) was assessed throughout the operation, and continued until an hour after the double-cuff tourniquet was removed. Results: The mean operation time after the deflation of the double-cuff tourniquet was 20.12 ± 6.1 minutes. Moreover, the mean NRS for the post-deflation time was insignificant (NRS = 2), and only one patient during first 20 minutes received opioids. Conclusions: This study showed that a pneumatic arm tourniquet as an adjunct to IVRA provides acceptable analgesia following the deflation of the double- cuff tourniquet for relieving surgical pain.

  6. How to control self-digestion: transcriptional, post-transcriptional, and post-translational regulation of autophagy.

    PubMed

    Feng, Yuchen; Yao, Zhiyuan; Klionsky, Daniel J

    2015-06-01

    Macroautophagy (hereafter autophagy), literally defined as a type of self-eating, is a dynamic cellular process in which cytoplasm is sequestered within a unique compartment termed the phagophore. Upon completion, the phagophore matures into a double-membrane autophagosome that fuses with the lysosome or vacuole, allowing degradation of the cargo. Nonselective autophagy is primarily a cytoprotective response to various types of stress; however, the process can also be highly selective. Autophagy is involved in various aspects of cell physiology, and its dysregulation is associated with a range of diseases. The regulation of autophagy is complex, and the process must be properly modulated to maintain cellular homeostasis. In this review, we focus on the current state of knowledge concerning transcriptional, post-transcriptional, and post-translational regulation of autophagy in yeast and mammals. PMID:25759175

  7. 32 CFR 643.120 - Post offices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been...

  8. 32 CFR 643.120 - Post offices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been...

  9. 32 CFR 643.120 - Post offices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been...

  10. 32 CFR 643.120 - Post offices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been...

  11. 32 CFR 643.120 - Post offices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been...

  12. Intravaginally applied oxytocin improves post-menopausal vaginal atrophy

    PubMed Central

    Uvnäs-Moberg, Kerstin; Jonasson, Aino F

    2015-01-01

    Objective To explore the efficacy of local oxytocin for the treatment of post-menopausal vaginal atrophy. Design Double-blinded randomised controlled trial. Setting Healthy post-menopausal women in Stockholm, Sweden. Participants Sixty four post-menopausal women between February and June 2012 at the Karolinska University Hospital Huddinge/Sweden. Main outcome measures The efficacy of oxytocin for treatment of vaginal atrophy after seven weeks and cytological evaluation. Results The percentage of superficial cells in the vaginal smears and the maturation values were significantly increased after seven weeks of treatment with vagitocin 400 IU (p = 0.0288 and p = 0.0002, respectively). The vaginal pH decreased significantly after seven weeks of treatment with vagitocin 100 IU (p = 0.02). The scores of vaginal atrophy, according to the histological evaluation, were significantly reduced after administration of vagitocin 100 IU (p = 0.03). The thickness of the endometrium did not differ between the treatment and placebo groups after seven weeks of treatment. The symptom experienced as the most bothersome was significantly reduced after seven weeks of treatment in the women receiving vagitocin 400 IU compared to women in the placebo group (p = 0.0089). Conclusions Treatment with intravaginally applied oxytocin could be an alternative to local estrogen treatment in women with post-menopausal vaginal atrophy. PMID:25995333

  13. The biomedicalisation of illegal abortion: the double life of misoprostol in Brazil.

    PubMed

    Zordo, Silvia De

    2016-01-01

    This paper examines the double life of misoprostol in Brazil, where it is illegally used by women as an abortifacient and legally used in obstetric hospital wards. Based on my doctoral and post-doctoral anthropological research on contraception and abortion in Salvador, Bahia, this paper initially traces the "conversion" of misoprostol from a drug to treat ulcers to a self-administered abortifacient in Latin America, and its later conversion to aneclectic global obstetric tool. It then shows how, while reducing maternal mortality, its use as an illegal abortifacient has reinforced the double reproductive citizenship regime existing in countries with restrictive abortion laws and poor post-abortion care services, where poor women using it illegally are stigmatised, discriminated against and exposed to potentially severe health risks. PMID:27008072

  14. Successful surgical repair of a triple cardiac rupture using modified cohesive double patch technique.

    PubMed

    Dorobantu, Lucian Florin; Stiru, Ovidiu; Iliescu, Vlad Anton

    2016-02-01

    Introduction The association between both left and right ventricular free wall ruptures (FWR) and post-infarction anterior ventricular septal defect (VSD) is an exceptional situation. Case report We present the case of a patient who developed a VSD and two FWRs (of the left and right ventricle, respectively) shortly after the onset of an anterior AMI. We surgically closed this complex rupture using the cohesive double patch technique with two Teflon patches combined with an infarct exclusion technique. The left and right ventricular patches were attached cohesively to the septal wall and the infarcted area was excluded without reducing the left ventricular cavity. Conclusion Association between post-infarction ventricular septal rupture and both left and right free wall ruptures are a very rare and dangerous situation. The modified cohesive double patch technique associated the modified Cooley technique seems to be the correct surgical solution. PMID:27385145

  15. Post-Traumatic Stress Disorder

    MedlinePlus

    ... PTSD include violent personal assaults, natural or human-caused disasters, accidents, or military combat. For Consumers General Information Post-Traumatic Stress Disorder ( NIMH ) Anxiety Information Stress Information Depression Information St. John's Wort Information See more Research ...

  16. Post-Traumatic Stress Disorder

    MedlinePlus

    ... Physician September 01, 2000, http://www.aafp.org/afp/20000901/1035.html) Post-traumatic Stress Reactions Following ... Physician August 01, 1999, http://www.aafp.org/afp/990800ap/524.html) Written by familydoctor.org editorial ...

  17. [Post-mortem microbiology analysis].

    PubMed

    Fernández-Rodríguez, Amparo; Alberola, Juan; Cohen, Marta Cecilia

    2013-12-01

    Post-mortem microbiology is useful in both clinical and forensic autopsies, and allows a suspected infection to be confirmed. Indeed, it is routinely applied to donor studies in the clinical setting, as well as in sudden and unexpected death in the forensic field. Implementation of specific sampling techniques in autopsy can minimize the possibility of contamination, making interpretation of the results easier. Specific interpretation criteria for post-mortem cultures, the use of molecular diagnosis, and its fusion with molecular biology and histopathology have led to post-mortem microbiology playing a major role in autopsy. Multidisciplinary work involving microbiologists, pathologists, and forensic physicians will help to improve the achievements of post-mortem microbiology, prevent infectious diseases, and contribute to a healthier population. PMID:23195835

  18. Post-traumatic stress disorder

    MedlinePlus

    Post-traumatic stress disorder (PTSD) is a type of anxiety disorder . It can occur after you have gone through an extreme ... Normally, after the event, the body recovers. The stress hormones and chemicals the body releases due to ...

  19. Double-Swivel Mechanism For Reliable Release

    NASA Technical Reports Server (NTRS)

    King, Guy L.; Schneider, William C.

    1990-01-01

    Double-swivel toggle mechanism releases large, heavy objects reliably. Double-swiveling action of mechanism ensures it clears restraining pins upon release. Pins retain toggle and its load. If pin fails to withdraw at designated time for releasing payload, toggle swivels about its upper ball, and ring swivels about lower ball so ring flange clears failed pin. Double-swivel action ensures disengagement even it two pins fail to withdraw.

  20. Double-patterning decomposition, design compliance, and verification algorithms at 32nm hp

    NASA Astrophysics Data System (ADS)

    Tritchkov, Alexander; Glotov, Petr; Komirenko, Sergiy; Sahouria, Emile; Torres, Andres; Seoud, Ahmed; Wiaux, Vincent

    2008-10-01

    Double patterning (DP) technology is one of the main candidates for RET of critical layers at 32nm hp. DP technology is a strong RET technique that must be considered throughout the IC design and post tapeout flows. We present a complete DP technology strategy including a DRC/DFM component, physical synthesis support and mask synthesis. In particular, the methodology contains: - A DRC-like layout DP compliance and design verification functions; - A parameterization scheme that codifies manufacturing knowledge and capability; - Judicious use of physical effect simulation to improve double-patterning quality; - An efficient, high capacity mask synthesis function for post-tapeout processing; - A verification function to determine the correctness and qualify of a DP solution; Double patterning technology requires decomposition of the design to relax the pitch and effectively allows processing with k1 factors smaller than the theoretical Rayleigh limit of 0.25. The traditional DP processes Litho-Etch-Litho- Etch (LELE) [1] requires an additional develop and etch step, which eliminates the resolution degradation which occurs in multiple exposure processed in the same resist layer. The theoretical k1 for a double-patterning technology applied to a 32nm half-pitch design using a 1.35NA 193nm imaging system is 0.44, whereas the k1 for a single-patterning of this same design would be 0.22 [2], which is sub-resolution. This paper demonstrates the methods developed at Mentor Graphics for double patterning design compliance and decomposition in an effort to minimize the impact of mask-to-mask registration and process variance. It also demonstrates verification solution implementation in the chip design flow and post-tapeout flow.

  1. Electroweak boson production in double parton scattering

    NASA Astrophysics Data System (ADS)

    Golec-Biernat, Krzysztof; Lewandowska, Emilia

    2014-11-01

    We study the W+W- and Z0Z0 electroweak boson production in double parton scattering using QCD evolution equations for double parton distributions. In particular, we analyze the impact of splitting terms in the evolution equations on the double parton scattering cross sections. Unlike the standard terms, the splitting terms are not suppressed for large values of the relative momentum of two partons in the double parton scattering. Thus, they play an important role which we discuss in detail for the single splitting contribution to the cross sections under the study.

  2. Choreographing the Double Strand Break Response: Ubiquitin and SUMO Control of Nuclear Architecture

    PubMed Central

    Harding, Shane M.; Greenberg, Roger A.

    2016-01-01

    The cellular response to DNA double strand breaks (DSBs) is a multifaceted signaling program that centers on post-translational modifications including phosphorylation, ubiquitylation and SUMOylation. In this review we discuss how ubiquitin and SUMO orchestrate the recognition of DSBs and explore how this influences chromatin organization. We discuss functional outcomes of this response including transcriptional silencing and how pre-existing chromatin states may control the DSB response and the maintenance of genomic stability. PMID:27375678

  3. Sensitivity enhancement of 29Si double-quantum dipolar recoupling spectroscopy by Carr-Purcell-Meiboom-Gill acquisition method

    NASA Astrophysics Data System (ADS)

    Goswami, M.; Madhu, P. K.; Dittmer, J.; Nielsen, N. C.; Ganapathy, S.

    2009-08-01

    An enhancement in the detection sensitivity of dipolar recoupled 29Si double-quantum magic-angle spinning experiment is shown with a Carr-Purcell-Meiboom-Gill (CPMG) train of π pulses during the acquisition period. Symmetry-adapted pulse schemes, such as POST-C7 and SR26411, are used for the double-quantum excitation. Application of POST-C7-CPMG method for framework characterisation is demonstrated in the disordered and catalytically important ZSM-5 molecular sieve. Based on the observed double-quantum dipole-dipole correlations and the known T-site Si connectivities, the assignment of all the signals is made for the orthorhombic phase of the as-synthesised (CN form) material.

  4. [Management of post partum haemorrhage].

    PubMed

    Csorba, Roland

    2012-04-29

    Primary post partum haemorrhage is the most common form of major obstetric haemorrhage. The traditional definition of primary post partum haemorrhage is the loss of 500 ml or more of blood from the genital tract within 24 hours of the birth of a baby. Post partum haemorrhage can be minor (500-1000 ml) or major (more than 1000 ml). Major could be divided to moderate (1000-2000 ml) or severe (more than 2000 ml). The recommendations in this article apply to women experiencing primary post partum haemorrhage of 500 ml or more. Secondary post partum haemorrhage is defined as abnormal or excessive bleeding from the birth canal between 24 hours and 12 weeks postnatally. The main causes of the secondary form are: inflammations (endometritis), placental tissue retention, inadequate involution of the uterus and malignancy. Because of its importance as a leading cause of maternal morbidity and mortality, obstetric haemorrhage must be considered as a priority topic. According to the tragic and dramatic outcomes of this morbidity, and to the fact that most cases of post partum haemorrhage have no identifiable risk factors, the practical obstetricians should be aware of the accurate diagnosis and management of this illness. PMID:22543219

  5. Double Semions in Arbitrary Dimension

    NASA Astrophysics Data System (ADS)

    Freedman, Michael H.; Hastings, Matthew B.

    2016-03-01

    We present a generalization of the double semion topological quantum field theory to higher dimensions, as a theory of {d-1} dimensional surfaces in a d dimensional ambient space. We construct a local Hamiltonian that is a sum of commuting projectors and analyze the excitations and the ground state degeneracy. Defining a consistent set of local rules requires the sign structure of the ground state wavefunction to depend not just on the number of disconnected surfaces, but also upon their higher Betti numbers through the semicharacteristic. For odd d the theory is related to the toric code by a local unitary transformation, but for even d the dimension of the space of zero energy ground states is in general different from the toric code and for even {d > 2} it is also in general different from that of the twisted {Z_2} Dijkgraaf-Witten model.

  6. Predicting neutrinoless double beta decay

    SciTech Connect

    Hirsch, M.; Villanova del Moral, A.; Valle, J.W.F.

    2005-11-01

    We give predictions for the neutrinoless double beta decay rate in a simple variant of the A{sub 4} family symmetry model. We show that there is a lower bound for the {beta}{beta}{sub 0{nu}} amplitude even in the case of normal hierarchical neutrino masses, corresponding to an effective mass parameter vertical bar m{sub ee} vertical bar {>=}0.17{radical}({delta}m{sub ATM}{sup 2}). This result holds both for the CP conserving and CP violating cases. In the latter case we show explicitly that the lower bound on vertical bar m{sub ee} vertical bar is sensitive to the value of the Majorana phase. We conclude therefore that in our scheme, {beta}{beta}{sub 0{nu}} may be accessible to the next generation of high sensitivity experiments.

  7. Comparing double string theory actions

    NASA Astrophysics Data System (ADS)

    De Angelis, L.; Gionti S. J, G.; Marotta, R.; Pezzella, F.

    2014-04-01

    Aimed to a deeper comprehension of a manifestly T-dual invariant formulation of string theory, in this paper a detailed comparison between the non-covariant action proposed by Tseytlin and the covariant one proposed by Hull is done. These are obtained by making both the string coordinates and their duals explicitly appear, on the same footing, in the world-sheet action, so "doubling" the string coordinates along the compact dimensions. After a discussion on the nature of the constraints in both the models and the relative quantization, it results that the string coordinates and their duals behave like "non-commuting" phase space coordinates but their expressions in terms of Fourier modes generate the oscillator algebra of the standard bosonic string. A proof of the equivalence of the two formulations is given. Furthermore, open-string solutions are also discussed.

  8. Double Potoionization of Molecular Hydrogen

    NASA Astrophysics Data System (ADS)

    Vanroose, Wim

    2006-05-01

    We report a complete numerical solution of the Schr"odinger equation for the double photoionization of H2, a process where a single photon emits two electrons. The results suggest that the distribution of photoelectrons emitted from aligned molecules reflects electron correlation effects that are purely molecular in origin. It confirms recent experimental results in experiments on oriented hydrogen molecules. These experiments observed that the ejection pattern of the electrons depends sensitively on the bond distance between the two nuclei as well as the orientation with respect to the polarization of the photon. We give an overview of the numerical methods we used to solve the exact Schrodinger equation for this problem. We also discuss the different molecular effect we observe in our calculations and compare with experimental observations

  9. Post-16 update

    NASA Astrophysics Data System (ADS)

    1999-09-01

    Institute of Physics post-16 initiative, shaping the future Physics education based in IT - sorry ICT! Which, of course, makes for a nifty headline, but as is so often the case with neat slogans, little else. Two formative questions: What, in another decade, will the government of the day call `What you lot should be doing with computers'? and What, of the many things that currently exercise our intellects, will there be anything special to say about in a decade, concerning the use of computers in the teaching of physics? Advancing Physics represents some attempts to come to grips with the second of the two questions above. The first is left to a higher wisdom. In thinking about learning, what can we do with the huge processing power, increasingly available in smaller and less obtrusive packages? What will we do that helps people learn physics, both tomorrow and in 2009? Here are a few suggestions based on development work so far. Wide, reliable and shared access to well ordered learning resources. We have created a CD-ROM, with versions for both student and teacher, that provides a wide range of resources. These do not teach, but do provide. A commitment to allowing a course to evolve and adapt. Electronic publication puts the costs into origination, and not into publication and distribution. A website allows for the community of users to contribute. E-mail networks support individuals and propagate good practice. You can create and explore your own microworlds. The interactive nature of models, and the crafted relationships between the models and the natural world give an insight into the creative imaginary worlds of the physicist. The unreasonable, but pleasurable, success of mathematics in describing the natural world can come to the fore. Measurements that were not possible before are now possible. What was previously indirect, and inaccessible, now becomes a direct measurement, making relationships transparent in new and fruitful ways. The dichotomy between

  10. Post-Heading Heat Stress in Rice of South China during 1981-2010

    PubMed Central

    Shi, Peihua; Tang, Liang; Wang, Lihuan; Sun, Ting; Liu, Leilei; Cao, Weixing; Zhu, Yan

    2015-01-01

    Frequent extreme heat events are the serious threat to rice production, but the historical trend of heat stress associated with phenology shift and its impact on rice yield over a long period are poorly known. Based on the analysis of observed climate and phenology data from 228 stations in South China during 1981-2010, the spatio-temporal variation of post-heading heat stress was investigated among two single-season rice sub-regions in the northern Middle and Lower Reaches of Yangtze River (S-NMLYtz) and Southwest Plateau (S-SWP), and two double-season early rice sub-regions in the southern Middle and Lower Reaches of Yangtze River (DE-SMLYtz) and Southern China (DE-SC). Post-heading heat stress was more severe in DE-SMLYtz, west S-NMLYtz and east S-SWP than elsewhere, because of rice exposure to the hot season during post-heading stage. The spatial variation of post-heading heat stress was greater in single-season rice region than in double-season early rice region due to the greater spatial variation of heading and maturity dates. Post-heading heat stress increased from 1981 to 2010 in most areas, with significant increases in the east of double-season early rice region and west S-SWP. Phenology shift during 1981-2010 mitigated the increasing trends of heat stress in most areas, but not in west S-SWP. Post-heading heat stress played a dominated role in the reduction of rice yield in South China. Grain yield was more sensitive to post-heading heat stress in double-season early rice region than that in single-season rice region. Rice yield decreased by 1.5%, 6.2%, 9.7% and 4.6% in S-NMLYtz, S-SWP, DE-SMLYtz and DE-SC, respectively, because of post-heading heat stress during 1981-2010, although there were some uncertainties. Given the current level and potential increase of post-heading heat stress in South China, the specific adaptation or mitigation strategies are necessary for different sub-regions to stabilize rice production under heat stress. PMID:26110263

  11. Double meanings will not save the principle of double effect.

    PubMed

    Douglas, Charles D; Kerridge, Ian H; Ankeny, Rachel A

    2014-06-01

    In an article somewhat ironically entitled "Disambiguating Clinical Intentions," Lynn Jansen promotes an idea that should be bewildering to anyone familiar with the literature on the intention/foresight distinction. According to Jansen, "intention" has two commonsense meanings, one of which is equivalent to "foresight." Consequently, questions about intention are "infected" with ambiguity-people cannot tell what they mean and do not know how to answer them. This hypothesis is unsupported by evidence, but Jansen states it as if it were accepted fact. In this reply, we make explicit the multiple misrepresentations she has employed to make her hypothesis seem plausible. We also point out the ways in which it defies common sense. In particular, Jansen applies her thesis only to recent empirical research on the intentions of doctors, totally ignoring the widespread confusion that her assertion would imply in everyday life, in law, and indeed in religious and philosophical writings concerning the intention/foresight distinction and the Principle of Double Effect. PMID:24737837

  12. The COBRA Double Beta Decay Search Experiment

    NASA Astrophysics Data System (ADS)

    Stewart, D. Y.

    2006-11-01

    The COBRA experiment aims to use a large quantity of CdZnTe semiconductor detectors to search for neutrinoless double beta decay. The current status of the experiment is discussed, and new limits on several double beta modes are presented. Future plans for a large scale experiment are also described.

  13. The COBRA double-beta decay experiment

    NASA Astrophysics Data System (ADS)

    Stewart, D. Y.; COBRA Collaboration

    2007-09-01

    The COBRA experiment aims to use a large quantity of Cadmium-Zinc-Telluride (CdZnTe) semiconductor detectors to search for neutrinoless double-beta decay (0 υββ). The current status of the experiment is discussed, and new limits on several double-beta modes are presented. Future plans for a large-scale experiment are also described.

  14. Photometry of Faint Wide Doubles in Hydra

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried; Thuemen, Chris; Gould, Ross

    2015-11-01

    Images of several double stars in Hydra published on the "Double Star Imaging Project" Yahoo Group page suggest magnitude issues compared with the corresponding WDS catalog data per end of 2014. Taking additional images with V and B filters enabled photometry for these pairs, suggesting significant corrections to the old data in WDS.

  15. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, William C.

    1988-01-01

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached.

  16. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, W.C.

    1988-10-11

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached. 8 figs.

  17. Improved double planar probe data analysis technique

    SciTech Connect

    Ghim, Young-chul; Hershkowitz, Noah

    2009-03-15

    Plasma electron number density and ion number density in a dc multidipole weakly collisional Ar plasma are measured with a single planar Langmuir probe and a double planar probe, respectively. A factor of two discrepancy between the two density measurements is resolved by applying Sheridan's empirical formula [T. E. Sheridan, Phys. Plasmas 7, 3084 (2000)] for sheath expansion to the double probe data.

  18. Perspective: Double Jeopardy--Another Look.

    ERIC Educational Resources Information Center

    Bolduan, Linda M.; Dailey, Dianne K.

    1997-01-01

    Explores how a defendant can face a civil action and criminal prosecution for the same act without violating the principle of double jeopardy. For instance, burning down a house can engender criminal prosecution charges and a civil suit from the insurance company. Double jeopardy only applies to criminal actions. (MJP)

  19. Electric fields and double layers in plasmas

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-01-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  20. The Doubling Moment: Resurrecting Edgar Allan Poe

    ERIC Educational Resources Information Center

    Minnick, J. Bradley; Mergil, Fernando

    2008-01-01

    This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

  1. Double Eye Brow: A Rare Case Report

    PubMed Central

    Kar, Sudipta; Ghosh, Chiranjit; Bazmi, Badruddin Ahamed; Sarkar, Subrata

    2013-01-01

    Eye brows are essential for esthetic and functional purposes. Various kinds of eye brows are found in human species. Protective function is one of the important functions of eye brows. Double eye brow is a very rare condition found in human. This case report describes one of the rare cases of double eye brow. PMID:24574697

  2. Intrateam Communication and Performance in Doubles Tennis

    ERIC Educational Resources Information Center

    Lausic, Domagoj; Tennebaum, Gershon; Eccles, David; Jeong, Allan; Johnson, Tristan

    2009-01-01

    Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured…

  3. Speeded Recognition of Ungrammaticality: Double Violations.

    ERIC Educational Resources Information Center

    Moore, Timothy E.; Biederman, Irving

    1979-01-01

    The speed at which sentences with various kinds of violations could be rejected was studied. Compatible with the sequential model was the finding that noun-verb and adjective-noun double violations did not result in shorter reaction times than noun-verb single violations, although double violations were judged less acceptable. (Author/RD)

  4. Electron temperature differences and double layers

    NASA Technical Reports Server (NTRS)

    Chan, C.; Hershkowitz, N.; Lonngren, K. E.

    1983-01-01

    Electron temperature differences across plasma double layers are studied experimentally. It is shown that the temperature differences across a double layer can be varied and are not a result of thermalization of the bump-on-tail distribution. The implications of these results for electron thermal energy transport in laser-pellet and tandem-mirror experiments are also discussed.

  5. The COBRA Double Beta Decay Search Experiment

    SciTech Connect

    Stewart, D. Y.

    2006-11-17

    The COBRA experiment aims to use a large quantity of CdZnTe semiconductor detectors to search for neutrinoless double beta decay. The current status of the experiment is discussed, and new limits on several double beta modes are presented. Future plans for a large scale experiment are also described.

  6. Post-mortem clinical pharmacology

    PubMed Central

    Ferner, R E

    2008-01-01

    Clinical pharmacology assumes that deductions can be made about the concentrations of drugs from a knowledge of the pharmacokinetic parameters in an individual; and that the effects are related to the measured concentration. Post-mortem changes render the assumptions of clinical pharmacology largely invalid, and make the interpretation of concentrations measured in post-mortem samples difficult or impossible. Qualitative tests can show the presence of substances that were not present in life, and can fail to detect substances that led to death. Quantitative analysis is subject to error in itself, and because post-mortem concentrations vary in largely unpredictable ways with the site and time of sampling, as a result of the phenomenon of post-mortem redistribution. Consequently, compilations of ‘lethal concentrations’ are misleading. There is a lack of adequate studies of the true relationship between fatal events and the concentrations that can be measured subsequently, but without such studies, clinical pharmacologists and others should be wary of interpreting post-mortem measurements. PMID:18637886

  7. Double layers and circuits in astrophysics

    NASA Technical Reports Server (NTRS)

    Alfven, H.

    1986-01-01

    A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

  8. Entropic Step Doubling on W(430).

    NASA Astrophysics Data System (ADS)

    Conrad, Edward H.; Dey, Srijata; West, James; Kiriukhin, Sergei

    1996-03-01

    We present high resolution low energy electron diffraction (LEED) results for the W(430) surface. Unlike every other system studied to date, single atomic height steps on this surface become energetically unfavorable at elevated temperatures. Above 940 K, a two phase mixture of single and double height steps forms. The transition to double height steps is predicted on the basis of a simple model provided that unconventional defect energetics are invoked. Specifically, double height steps cost more than twice as much energy as single height steps, while kinks on the double height steps cost less energy than kinks on single height steps. Recent theoretical calculations independently confirm this energetics hierarchy. (W. Xu, J.B. Adams and T.L. Einstein (to be published).) The existence of the doubling transition sheds new light on previous self diffusion coefficient measurements for other stepped tungsten surfaces. (Y.M. Gong and R. Gomer, J. Chem. Phys. 88), 1359 (1988); 88, 1370 (1988).

  9. Instability limits for spontaneous double layer formation

    SciTech Connect

    Carr, J. Jr.; Galante, M. E.; McCarren, D.; Scime, E. E.; Sears, S.; VanDervort, R. W.; Magee, R. M.; Reynolds, E.

    2013-11-15

    We present time-resolved measurements that demonstrate that large amplitude electrostatic instabilities appear in pulsed, expanding helicon plasmas at the same time as particularly strong double layers appear in the expansion region. A significant cross-correlation between the electrostatic fluctuations and fluctuations in the number of ions accelerated by the double layer electric field is observed. No correlation is observed between the electrostatic fluctuations and ions that have not passed through the double layer. These measurements confirm that the simultaneous appearance of the electrostatic fluctuations and the double layer is not simple coincidence. In fact, the accelerated ion population is responsible for the growth of the instability. The double layer strength, and therefore, the velocity of the accelerated ions, is limited by the appearance of the electrostatic instability.

  10. Applicability of a double-undulator configuration

    NASA Astrophysics Data System (ADS)

    Huang, Jui-Che; Kitamura, Hideo; Yang, Chin-Kang; Chiu, Mau-Sen; Chang, Cheng-Hsiang; Hwang, Ching-Shiang

    2016-02-01

    The applicability of the double-undulator concept for an electron storage ring of 3-GeV class is evaluated based on the parameters of Taiwan Photon Source. In the soft X-ray case, the fundamental harmonic is mainly used, the interference effect is preserved at some level, which means that the brilliance from a double-undulator is expected to be much greater than that of a single undulator. In the hard X-ray case, harmonics number greater than five are generally used, the interference effect cannot, however, be preserved, which means that a double undulator configuration can be assumed to comprise two independent and uncorrelated sources. The total coherent flux obtained from a double-undulator configuration is found to be much less than twice that of a single undulator. The double-undulator concept is hence inapplicable in the hard X-ray region from the viewpoint of high coherent flux performance.

  11. Reliability Estimation for Double Containment Piping

    SciTech Connect

    L. Cadwallader; T. Pinna

    2012-08-01

    Double walled or double containment piping is considered for use in the ITER international project and other next-generation fusion device designs to provide an extra barrier for tritium gas and other radioactive materials. The extra barrier improves confinement of these materials and enhances safety of the facility. This paper describes some of the design challenges in designing double containment piping systems. There is also a brief review of a few operating experiences of double walled piping used with hazardous chemicals in different industries. This paper recommends approaches for the reliability analyst to use to quantify leakage from a double containment piping system in conceptual and more advanced designs. The paper also cites quantitative data that can be used to support such reliability analyses.

  12. Tests of general relativity from timing the double pulsar.

    PubMed

    Kramer, M; Stairs, I H; Manchester, R N; McLaughlin, M A; Lyne, A G; Ferdman, R D; Burgay, M; Lorimer, D R; Possenti, A; D'Amico, N; Sarkissian, J M; Hobbs, G B; Reynolds, J E; Freire, P C C; Camilo, F

    2006-10-01

    The double pulsar system PSR J0737-3039A/B is unique in that both neutron stars are detectable as radio pulsars. They are also known to have much higher mean orbital velocities and accelerations than those of other binary pulsars. The system is therefore a good candidate for testing Einstein's theory of general relativity and alternative theories of gravity in the strong-field regime. We report on precision timing observations taken over the 2.5 years since its discovery and present four independent strong-field tests of general relativity. These tests use the theory-independent mass ratio of the two stars. By measuring relativistic corrections to the Keplerian description of the orbital motion, we find that the "post-Keplerian" parameter s agrees with the value predicted by general relativity within an uncertainty of 0.05%, the most precise test yet obtained. We also show that the transverse velocity of the system's center of mass is extremely small. Combined with the system's location near the Sun, this result suggests that future tests of gravitational theories with the double pulsar will supersede the best current solar system tests. It also implies that the second-born pulsar may not have formed through the core collapse of a helium star, as is usually assumed. PMID:16973838

  13. Post-Newtonian gravitational bremsstrahlung

    NASA Technical Reports Server (NTRS)

    Turner, M.; Will, C. M.

    1977-01-01

    Formulae and numerical results are presented for the gravitational radiation emitted during a low-deflection encounter between two massive bodies. Results are valid through post-Newtonian order within general relativity. The gravitational waveform, the total luminosity and total emitted energy, the angular distribution of emitted energy, and the frequency spectrum are discussed in detail. A method boosting the accuracy of these quantities to post Newtonian order is also presented. A numerical comparison of results with those of Peters, and of Kovacs and Thorne shows that the post Newtonian method is reliable to better than 0.1 percent at v = 0.1 c, to a few percent at v = 0.35 c, and to 10 to 20 percent at v = 0.5 c.

  14. Double-disc gate valve

    DOEpatents

    Wheatley, Seth J.

    1979-01-01

    This invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewtih, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separtion of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve.

  15. Directionality Effect in Double Conditionals.

    PubMed

    Espino, Orlando; Sánchez-Curbelo, Isana; Bolaños-Medina, Alicia

    2015-01-01

    Directionality effect in deductive reasoning is a very well-known phenomenon that shows that the percentage of forward or backward inferences that participants make depends on the conditional form used. A new extension of the semantic hypothesis (Oberauer & Wilhelm, 2000) is presented to explain the directionality effect in double conditionals with different directionality. This hypothesis claims that the directional effect depends on which term plays the role of relatum. It also makes several novel claims which have been confirmed in three experiments: Experiments 1 and 2 showed there were more forward than backward inferences when the end-term that played the role of relatum was in the first premise, experiment 1: t (45) = 2.73, p < .01, experiment 2: t (38) = 12.06, p < .05, but there were more backward than forward inferences when the end-term that played the role of relatum was in the second premise, experiment 1: t (45) = 2.84, p < .01, experiment 2: t (38) = 2.21, p < .04. Experiment 3 showed that there was no directional effect when both end-terms played the role of relatum, t (34) = 1.39, p = .17, or when both middle-terms (or neither of the end-terms) played the role of relatum, t (34) = .78, p = .44. These experiments confirmed the predictions of the new extension of the semantic hypothesis. PMID:26239471

  16. The double life of DNA

    PubMed Central

    McMurray, Cynthia T.; Vijg, Jan

    2015-01-01

    This issue of Current Opinions focuses on the dual role of DNA in life and death. In ancient Roman religion and myth, Janus is the god who looks both to the past and to the future. He guides the beginnings of life, its progression from one condition to another, and he foresees distant events. The analogy to DNA could not be stronger. Closely interacting with the environment, our basic genetics provides the origin of life, guides the quality of health with age, predicts disease, and ultimately foresees our end. A shared and deep interest in the origin of life has long prompted our desire to define aging, and, ultimately, to understand whether it can be reversed. In this special issue, the authors collectively review concepts of normative aging, DNA instability, DNA repair, the genetic contribution of age and diet to disease, and how the basic molecular transactions of DNA give it a double life that guides health and survival, as well as the transitions to death. PMID:25282314

  17. Double-sided Relativistic Magnetron

    NASA Astrophysics Data System (ADS)

    Agafonov, A. V.; Krastelev, E. G.

    1997-05-01

    A new scheme of a symmetricaly powered relativistic magnetron and several methods of localised electron flow forming in an interaction region are proposed to increase an efficiency of relativistic magnetrons. As will be shown, a very important reason is the effect of nonsymmetric feeding of power from one side of a magnetron, which is typical for experiments. One-sided powering leads to the axial drift of electrons, to the transformation of transverse velocities of electrons to longitudinal one and to the generation of a parasitic e-beam which does not take part in energy exchange between electrons and waves at all. A special driver was designed for double-sided powering of relativistic magnetrons. The proposed system is compact, rigid and capable of reliable operation at high repetition rates, which is advantageous for many applications. Several smooth-bore magnetrons were tested by means of computer simulations using PIC code KARAT. The results showed a dramatical difference between the dynamics of electron flow for one- and two-sided power feeding of a structure under test. Design of a driver and computer simulation results are presented.

  18. Doubling of world population unlikely.

    PubMed

    Lutz, W; Sanderson, W; Scherbov, S

    1997-06-19

    Most national and international agencies producing population projections avoid addressing explicitly the issue of uncertainty. Typically, they provide either a single projection or a set of low, medium and high variants, and only very rarely do they give these projections a probabilistic interpretation. Probabilistic population projections have been developed for specific industrialized countries, mostly the United States, and are based largely on time-series analysis. On a global level, time-series analysis is not applicable because there is a lack of appropriate data, and for conceptual reasons such as the structural discontinuity caused by the demographic transition. Here we report on a new probabilistic approach that makes use of expert opinion on trends in fertility, mortality and migration, and on the 90 per cent uncertainty range of those trends in different parts of the world. We have used simulation techniques to derive probability distributions of population sizes and age structures for 13 regions of the world up to the year 2100. Among other things, we find that there is a probability of two-thirds that the world's population will not double in the twenty-first century. PMID:9194559

  19. The Double Absorbing Boundary method

    NASA Astrophysics Data System (ADS)

    Hagstrom, Thomas; Givoli, Dan; Rabinovich, Daniel; Bielak, Jacobo

    2014-02-01

    A new approach is devised for solving wave problems in unbounded domains. It has common features to each of two types of existing techniques: local high-order Absorbing Boundary Conditions (ABC) and Perfectly Matched Layers (PML). However, it is different from both and enjoys relative advantages with respect to both. The new method, called the Double Absorbing Boundary (DAB) method, is based on truncating the unbounded domain to produce a finite computational domain Ω, and on applying a local high-order ABC on two parallel artificial boundaries, which are a small distance apart, and thus form a thin non-reflecting layer. Auxiliary variables are defined on the two boundaries and inside the layer bounded by them, and participate in the numerical scheme. The DAB method is first introduced in general terms, using the 2D scalar time-dependent wave equation as a model. Then it is applied to the 1D Klein-Gordon equation, using finite difference discretization in space and time, and to the 2D wave equation in a wave guide, using finite element discretization in space and dissipative time stepping. The computational aspects of the method are discussed, and numerical experiments demonstrate its performance.

  20. Double groups and projective representations

    NASA Astrophysics Data System (ADS)

    Altmann, S. L.; Herzig, P.

    Some problems are discussed in relation to the usual treatment of improper groups through their double groups, in particular the identification (rather than the mere isomorphism) of such groups as C3v and D3. The enhancement of SU(2) by the addition of the inversion is analysed for this purpose. This requires a careful discussion of the behaviour of spinors under inversion and two types of spinors are defined, Cartan and Pauli spinors, that behave differently with respect to inversion, although it is shown that this difference merely entails a choice of gauge in the language of projective representations. A distinction is proposed between the inversion operation and the parity operator: when the former is realized as a binary rotation in 4-space, the latter can be identified with its infinitesimal generator. The passage from SO(3) to O(3) (group of all proper and improper rotations) is studied and a hitherto unknown faithful projective representations of O(3) is given. It is shown how spinor representations can be constructed for improper point groups in either the Cartan or Pauli gauges. A choice of gauge is proposed to ensure agreement with current practice in angular momentum theory and with that in single point groups. As an example, Clebsch-Gordan coefficients are constructed for C3v.

  1. RCRA post-closure permits

    SciTech Connect

    Not Available

    1993-05-01

    The Resource Conservation and Recovery Act (RCRA) requires that hazardous waste management facilities operate in accordance with permits granted by the US Environmental Protection Agency (EPA) or a State authorized to carry out the RCRA Subtitle C program. Several categories of permits (including treatment, storage, and disposal permits; research, development, and demonstration permits; post-closure permits; emergency permits; permits-by-rule; and trial burn and land treatment demonstration permits) are issued under the RCRA Subtitle C program. This Information Brief focuses on post-closure permitting requirements under 40 CFR 270.1(c).

  2. Numerical Comparison of Active Acoustic and Structural Noise Control in a Stiffened Double Wall Cylinder

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.

    1996-01-01

    The active acoustic and structural noise control characteristics of a double wall cylinder with and without ring stiffeners were numerically evaluated. An exterior monopole was assumed to acoustically excite the outside of the double wall cylinder at an acoustic cavity resonance frequency. Structural modal vibration properties of the inner and outer shells were analyzed by post-processing the results from a finite element analysis. A boundary element approach was used to calculate the acoustic cavity response and the coupled structural-acoustic interaction. In the frequency region of interest, below 500 Hz, all structural resonant modes were found to be acoustically slow and the nonresonant modal response to be dominant. Active sound transmission control was achieved by control forces applied to the inner or outer shell, or acoustic control monopoles placed just outside the inner or outer shell. A least mean square technique was used to minimize the interior sound pressures at the nodes of a data recovery mesh. Results showed that single acoustic control monopoles placed just outside the inner or outer shells resulted in better sound transmission control than six distributed point forces applied to either one of the shells. Adding stiffeners to the double wall structure constrained the modal vibrations of the shells, making the double wall stiffer with associated higher modal frequencies. Active noise control obtained for the stiffened double wall configurations was less than for the unstiffened cylinder. In all cases, the acoustic control monopoles controlled the sound transmission into the interior better than the structural control forces.

  3. 39 CFR 241.1 - Post offices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Post offices. 241.1 Section 241.1 Postal Service... DISCONTINUANCE § 241.1 Post offices. Post Offices are established and maintained at locations deemed necessary to... geographic boundaries. A Post Office may be operated or staffed by a postmaster or by another type of...

  4. 39 CFR 241.1 - Post offices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Post offices. 241.1 Section 241.1 Postal Service... DISCONTINUANCE § 241.1 Post offices. (a) Establishment. Post Offices are established and maintained at locations... within specified geographic boundaries. A Post Office may be operated or staffed by a postmaster or...

  5. 39 CFR 241.1 - Post offices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Post offices. 241.1 Section 241.1 Postal Service... DISCONTINUANCE § 241.1 Post offices. Post Offices are established and maintained at locations deemed necessary to... geographic boundaries. A Post Office may be operated or staffed by a postmaster or by another type of...

  6. 77 FR 6606 - DoubleLine Capital LP and DoubleLine Funds Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... COMMISSION DoubleLine Capital LP and DoubleLine Funds Trust; Notice of Application February 2, 2012. AGENCY... relying on rule 12d1-2 under the Act to invest in certain financial instruments. APPLICANTS: DoubleLine Capital LP (``DoubleLine'') and DoubleLine Funds Trust (``Trust''). FILING DATE: The application was...

  7. Microswitch- and VOCA-Assisted Programs for Two Post-Coma Persons with Minimally Conscious State and Pervasive Motor Disabilities

    ERIC Educational Resources Information Center

    Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Buonocunto, Francesca; Sacco, Valentina; Colonna, Fabio; Navarro, Jorge; Oliva, Doretta; Signorino, Mario; Megna, Gianfranco

    2009-01-01

    Intervention programs, based on learning principles and assistive technology, were assessed in two studies with two post-coma men with minimally conscious state and pervasive motor disabilities. Study I assessed a program that included (a) an optic microswitch, activated via double blinking, which allowed a man direct access to brief music…

  8. Reconsidering Post-Traumatic Stress

    ERIC Educational Resources Information Center

    Berman, Dene S.; Davis-Berman, Jennifer

    2005-01-01

    This article serves to challenge the prevailing wisdom that suggests that most trauma is followed by post-traumatic stress disorder (PTSD), and is best treated with critical incident stress debriefing (CISD). Instead, recent evidence suggests that many individuals exposed to stress do not experience stress responses. Even those who do, however,…

  9. Chaos Theory and Post Modernism

    ERIC Educational Resources Information Center

    Snell, Joel

    2009-01-01

    Chaos theory is often associated with post modernism. However, one may make the point that both terms are misunderstood. The point of this article is to define both terms and indicate their relationship. Description: Chaos theory is associated with a definition of a theory dealing with variables (butterflies) that are not directly related to a…

  10. Post High School Plans Survey.

    ERIC Educational Resources Information Center

    Muskingum Area Technical Coll., Zanesville, OH.

    This survey investigated the immediate after-high school plans of high school juniors, with a special emphasis on post-secondary education intentions. The survey included the responses of 1,064 students from 12 high schools. Forty-nine percent of the respondents indicated that they planned to attend a four-year college or university, 18 percent…

  11. Job Posting: An Industry Survey

    ERIC Educational Resources Information Center

    Dahl, Dave R.; Pinto, Patrick R.

    1977-01-01

    Reports a survey to determine practices among metalworking firms in Minnesota covering such topics as whether or not the company had a formal or informal job posting system, the actual mechanics of the system, union influence on its design, feedback to unsuccessful job bidders, and current employee acceptance of the system. Recommendations are…

  12. Pair take top science posts

    NASA Astrophysics Data System (ADS)

    Pockley, Peter

    2008-11-01

    Australia's science minister Kim Carr has appointed physical scientists to key posts. Penny Sackett, an astronomer, takes over as the government's chief scientist this month, while in January geologist Megan Clark will become chief executive of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the county's largest research agency. Both five-year appointments have been welcomed by researchers.

  13. Issues in post-literacy

    NASA Astrophysics Data System (ADS)

    Dave, Ravindra H.; Ouane, Adama; Sutton, Peter

    1989-12-01

    While school enrolments have been rising, the absolute number of illiterates in the world has grown too. Eradication of adult illiteracy and universalization of primary education are hindered by high drop-out in schools and relapse into illiteracy among adults. Post-literacy programmes seek to stop this reversal by ensuring retention, application and continuation of literacy skills. The Unesco Institute for Education (UIE) has been researching and promoting post-literacy strategies since 1980, but finds that most projects do not include provision for post-literacy from the outset, despite the evident need. Those programmes which have been mounted use a variety of strategies, which UIE has analysed in 12 categories. The exact delimitation of the post-literacy stage in the lifelong education continuum differs from project to project, and the emphasis on individual or societal advance depends on local perceptions of the goals of development. Examples are given of successful programmes, and the challenges of increasing participation and motivation, securing adequate funding, and making efficient and flexible use of institutional facilities are discussed.

  14. Double-Disk Dark Matter

    NASA Astrophysics Data System (ADS)

    Fan, JiJi; Katz, Andrey; Randall, Lisa; Reece, Matthew

    2013-09-01

    Based on observational tests of large scale structure and constraints on halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant component’s interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar to those in the baryonic sector. We explore a simple model in which DDDM can cool efficiently and form a disk within galaxies, and we evaluate some of the possible observational signatures. The most prominent signal of such a scenario could be an enhanced indirect detection signature with a distinctive spatial distribution. Even though subdominant, the enhanced density at the center of the galaxy and possibly throughout the plane of the galaxy (depending on precise alignment) can lead to large boost factors, and could even explain a signature as large as the 130 GeV Fermi line. Such scenarios also predict additional dark radiation degrees of freedom that could soon be detectable and would influence the interpretation of future data, such as that from Planck and from the Gaia satellite. We consider this to be the first step toward exploring a rich array of new possibilities for dark matter dynamics.

  15. Comparison between Double J (DJ) Ureteral Stenting and Percutaneous Nephrostomy (PCN) in Obstructive Uropathy

    PubMed Central

    Ahmad, Iftikhar; Saeed Pansota, Mudassar; Tariq, Muhammad; Shahzad Saleem, Muhammad; Ali Tabassum, Shafqat; Hussain, Akbar

    2013-01-01

    Objective: To compare the complications rate of percutaneous nephrostomy and double J ureteral stenting in the management of obstructive uropathy. Methodology: Total number of 300 patients of age 20-80 years who underwent JJ stenting or percutaneous nephrostomy for obstructive uropathy were included in this study. Patients were divided in two groups i.e. A & B. In group A, 100 patients who underwent double J ureteral stenting while in group B, 200 patients who underwent percutaneous nephrostomy tube insertion were included. The stent was inserted retrograde by using cystoscope, under mild sedation or local anesthesia. While the percutaneous nephrostomy was done under ultrasound guidance by using local anesthetic agent. Complications were noted in immediate post-operative period and on follow up. Results: Majority of the patients were between 36 to 50 years of age with male to female ratio was 2.6:1. The most common cause of obstructive uropathy was stone disease i.e. renal, ureteric or both. Post DJ stent, complications like painful trigon irritation, septicemia, haematuria and stent encrustation were seen in 12.0%, 7.0%, 10.0% and 5.0% patients respectively. On the other hand, post-PCN septicemia, bleeding and tube dislodgment or blockage was seen in 3.5%, 4.5% and 4.5% respectively. In this study, overall success rate for double J stenting was up to 83.0% and for percutaneous nephrostomy (PCN) was 92.0% (p<0.0001). Conclusion: Percutaneous nephrostomy is a safe and better method of temporary urinary diversion than double J stenting for management of obstructive uropathy with lower incidence of complications. PMID:24353616

  16. Single and double photoionization of Li2

    NASA Astrophysics Data System (ADS)

    Pindzola, M. S.; Li, Ye; Colgan, J.

    2015-01-01

    Time-dependent close-coupling methods are used to study the single and double photoionization of Li2. Formulations for both one-active and two-active electron methods make use of Hartree with local exchange potentials for the core electrons. Both the single and double photoionization cross sections for Li2 are found to be larger for linear polarization than for circular polarization, in sharp contrast to that found before for H2. In particular the double photoionization cross sections for Li2 are found to be approximately five times larger than for H2 and thus more easily observed by future experiments.

  17. Double Dens Invaginatus: Report of Three Cases

    PubMed Central

    Zengin, A. Zeynep; Sumer, A. Pinar; Celenk, Peruze

    2009-01-01

    Dens invaginatus results from an infolding of the outer surface of a tooth. The clinical importance of dens invaginatus results from the risk of pulpal disease. So, all clinicians should be aware of this anomaly. The presence of double dens invaginatus is extremely rare. This article presents three cases of double dens invaginatus in permanent maxillary lateral incisors, one with preventive restoration on its palatal surface. They were classified as double dens invaginatus because of two enamel lined invaginations presented in the crowns of these teeth. PMID:19262734

  18. Negative Coulomb Drag in Double Bilayer Graphene.

    PubMed

    Li, J I A; Taniguchi, T; Watanabe, K; Hone, J; Levchenko, A; Dean, C R

    2016-07-22

    We report on an experimental measurement of Coulomb drag in a double quantum well structure consisting of bilayer-bilayer graphene, separated by few layer hexagonal boron nitride. At low temperatures and intermediate densities, a novel negative drag response with an inverse sign is observed, distinct from the momentum and energy drag mechanisms previously reported in double monolayer graphene. By varying the device aspect ratio, the negative drag component is suppressed and a response consistent with pure momentum drag is recovered. In the momentum drag dominated regime, excellent quantitative agreement with the density and temperature dependence predicted for double bilayer graphene is found. PMID:27494491

  19. Double-reed exhaust valve engine

    SciTech Connect

    Bennett, Charles L.

    2015-06-30

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

  20. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-01

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components. PMID:17794721

  1. Double emulsions in a microfluidic device

    NASA Astrophysics Data System (ADS)

    Pannacci, Nicolas; Lockhart, Thibaut; Willaime, Hervé; Tabeling, Patrick

    2007-11-01

    Double emulsions (emulsion of two liquids dispersed in a third liquid phase) are widely used in cosmetics, medicine or food industry. We are interested in producing very well controlled double emulsions in a microfluidic device and predicting the morphology (complete engulfing, non-engulfing or partial engulfing called ``janus'') from classical energetic considerations. We use a double flow focusing geometry with a 100 micrometers cross section for the PDMS microsystem. We compare theoretical and experimental morphologies flowing thirty triplets of immiscible fluids. We observe quite a good agreement and show that microfluidic technology may permit to get non standard objects.

  2. Three step double layers in the laboratory. [plasma physics

    NASA Technical Reports Server (NTRS)

    Bailey, Andrew, III; Hershkowitz, Noah

    1988-01-01

    A new class of stationary double layer structure, with three or more distinct steps, is demonstrated in the laboratory. A large monotonic potential increase results from a series of smaller double layers. In many respects, these double layer structures resemble those inferred from satellite measurements of auroral double layers. This new class of double layer appears to depend on turbulence for its existence and to be a hybrid structure, intermediate between anomalous resistivity and BGK double layers.

  3. Application of a Double Aza-Michael Reaction in a ‘Click, Click, Cy-Click’ Strategy: From Bench to Flow

    PubMed Central

    Zang, Qin; Javed, Salim; Ullah, Farman; Zhou, Aihua; Knudtson, Christopher A.; Bi, Danse; Basha, Fatima Z.; Organ, Michael G.; Hanson, Paul R.

    2011-01-01

    The development of a ‘click, click, cy-click’ process utilizing a double aza-Michael reaction to generate functionalized 1,2,5-thiadiazepane 1,1-dioxides is reported. Optimization in flow, followed by scale out of the inter-/intramolecular double aza-Michael addition has also been realized using a microwave-assisted, continuous flow organic synthesis platform (MACOS). In addition, a facile one-pot, sequential strategy employing in situ Huisgen cycloaddition post-double aza-Michael has been accomplished, and is applicable to library synthesis. PMID:21927510

  4. Relativistic astrophysics. [studies of gravitational radiation in asymptotic de sitter space and post Newtonian approximation

    NASA Technical Reports Server (NTRS)

    Smalley, L. L.

    1975-01-01

    The coordinate independence of gravitational radiation and the parameterized post-Newtonian approximation from which it is extended are described. The general consistency of the field equations with Bianchi identities, gauge conditions, and the Newtonian limit of the perfect fluid equations of hydrodynamics are studied. A technique of modification is indicated for application to vector-metric or double metric theories, as well as to scalar-tensor theories.

  5. Double Pomeron physics at the LHC

    SciTech Connect

    Albrow, Michael G.; /Fermilab

    2005-07-01

    The author discusses central exclusive production, also known as Double Pomeron Exchange DIPE, from the ISR through the Tevatron to the LHC. There the author emphasizes the interest of exclusive Higgs and W{sup +}W{sup -}/ZZ production.

  6. Double field theory: a pedagogical review

    NASA Astrophysics Data System (ADS)

    Aldazabal, Gerardo; Marqués, Diego; Núñez, Carmen

    2013-08-01

    Double field theory (DFT) is a proposal to incorporate T-duality, a distinctive symmetry of string theory, as a symmetry of a field theory defined on a double configuration space. The aim of this review is to provide a pedagogical presentation of DFT and its applications. We first introduce some basic ideas on T-duality and supergravity in order to proceed to the construction of generalized diffeomorphisms and an invariant action on the double space. Steps towards the construction of a geometry on the double space are discussed. We then address generalized Scherk-Schwarz compactifications of DFT and their connection to gauged supergravity and flux compactifications. We also discuss U-duality extensions and present a brief parcours on worldsheet approaches to DFT. Finally, we provide a summary of other developments and applications that are not discussed in detail in the review.

  7. A new hydrodynamic analysis of double layers

    NASA Technical Reports Server (NTRS)

    Hora, Heinrich

    1987-01-01

    A genuine two-fluid model of plasmas with collisions permits the calculation of dynamic (not necessarily static) electric fields and double layers inside of plasmas including oscillations and damping. For the first time a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser-produced plasmas showing very high dynamic electric fields in nonlinear force-produced cavitous and inverted double layers in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. Results are the rotation of plasmas in magnetic fields and a new second harmonic resonance, explanation of the measured inverted double layers, explanation of the observed density-independent, second harmonics emission from laser-produced plasmas, and a laser acceleration scheme by the very high fields of the double layers.

  8. Review of modern double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Barabash, A. S.

    2015-10-01

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T1/2(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino ( < 0.46 eV) and a coupling constant of Majoron to neutrino ( < 1.3 . 10-5) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to at the level of ˜ 0.01-0.1 eV are discussed.

  9. Double logarithmic asymptotic behavior in quantum chromodynamics

    SciTech Connect

    Kirschner, R.

    1981-08-01

    The double logarithmic contributions to the quark-(anti)quark scattering and annihilation amplitudes are summed to all orders in quantum chromodynamics. The results are a generalization of the calculations of Gorshkov et al. in the case of quantum electrodynamics.

  10. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Rob; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This slide presentation reviews the power frequencies for the doubled fiber laser. It includes information on the 780 nm laser, second harmonic generation in one crystal, cascading crystals, the tenability of laser systems, laser cooling, and directions for future work.

  11. Inverse solutions for tilting orthogonal double prisms.

    PubMed

    Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren

    2014-06-10

    An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields. PMID:24921137

  12. Frequency Doubling Broadband Light in Multiple Crystals

    SciTech Connect

    ALFORD,WILLIAM J.; SMITH,ARLEE V.

    2000-07-26

    The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.

  13. Over-under double-pass interferometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A. (Inventor)

    1977-01-01

    An over-under double pass interferometer in which the beamsplitter area and thickness can be reduced to conform only with optical flatness considerations was achieved by offsetting the optical center line of one cat's-eye retroreflector relative to the optical center line of the other in order that one split beam be folded into a plane distinct from the other folded split beam. The beamsplitter is made transparent in one area for a first folded beam to be passed to a mirror for doubling back and is made totally reflective in another area for the second folded beam to be reflected to a mirror for doubling back. The two beams thus doubled back are combined in the central, beamsplitting area of the beamsplitting and passed to a detector. This makes the beamsplitter insensitive to minimum thickness requirements and selection of material.

  14. Nonlinear dynamics of a double bilipid membrane.

    PubMed

    Sample, C; Golovin, A A

    2007-09-01

    The nonlinear dynamics of a biological double membrane that consists of two coupled lipid bilayers, typical of some intracellular organelles such as mitochondria or nuclei, is studied. A phenomenological free-energy functional is formulated in which the curvatures of the two parts of the double membrane and the distance between them are coupled to the lipid chemical composition. The derived nonlinear evolution equations for the double-membrane dynamics are studied analytically and numerically. A linear stability analysis is performed, and the domains of parameters are found in which the double membrane is stable. For the parameter values corresponding to an unstable membrane, numerical simulations are performed that reveal various types of complex dynamics, including the formation of stationary, spatially periodic patterns. PMID:17930289

  15. Rosalind Franklin and the Double Helix

    NASA Astrophysics Data System (ADS)

    Elkin, Lynne Osman

    2003-03-01

    Although she made essential contributions toward elucidating the structure of DNA, Rosalind Franklin is known to many only as seen through the distorting lens of James Watson's book, The Double Helix.

  16. Review of modern double beta decay experiments

    SciTech Connect

    Barabash, A. S.

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  17. Improved double beam, vacuum far infrared spectrophotometer.

    PubMed

    Iwahashi, I; Matsumoto, K; Matsudaira, S; Minami, S; Yoshinaga, H

    1969-03-01

    A double beam far ir spectrophotometer was improved in order to give more convenience and higher performance. The instrument is evacuable and the sample chamber alone can also be purged with dry air to remove water vapor. Three photometric systems, i.e., conventional double beam, double beam double chopping, and single beam systems can be selected for versatile measurements. The use of an efficient transmission filter system, not involving deliquescent crystals, results in many operational advantages. Accordingly, high resolution can be obtained through the entire spectral region from 400 cm(-1) to 30 cm(-1) Moreover, 30-min scan over the entire spectral region is achieved by completely automatic operation with a refined control system. PMID:20072263

  18. Nonlinear dynamics of a double bilipid membrane

    NASA Astrophysics Data System (ADS)

    Sample, C.; Golovin, A. A.

    2007-09-01

    The nonlinear dynamics of a biological double membrane that consists of two coupled lipid bilayers, typical of some intracellular organelles such as mitochondria or nuclei, is studied. A phenomenological free-energy functional is formulated in which the curvatures of the two parts of the double membrane and the distance between them are coupled to the lipid chemical composition. The derived nonlinear evolution equations for the double-membrane dynamics are studied analytically and numerically. A linear stability analysis is performed, and the domains of parameters are found in which the double membrane is stable. For the parameter values corresponding to an unstable membrane, numerical simulations are performed that reveal various types of complex dynamics, including the formation of stationary, spatially periodic patterns.

  19. Tuberculosis drug discovery in the post-post-genomic era

    PubMed Central

    Lechartier, Benoit; Rybniker, Jan; Zumla, Alimuddin; Cole, Stewart T

    2014-01-01

    The expectation that genomics would result in new therapeutic interventions for infectious diseases remains unfulfilled. In the post-genomic era, the decade immediately following the availability of the genome sequence of Mycobacterium tuberculosis, tuberculosis (TB) drug discovery relied heavily on the target-based approach but this proved unsuccessful leading to a return to whole cell screening. Genomics underpinned screening by providing knowledge and many enabling technologies, most importantly whole genome resequencing to find resistance mutations and targets, and this resulted in a selection of leads and new TB drug candidates that are reviewed here. Unexpectedly, many new targets were found to be ‘promiscuous’ as they were inhibited by a variety of different compounds. In the post-post-genomics era, more advanced technologies have been implemented and these include high-content screening, screening for inhibitors of latency, the use of conditional knock-down mutants for validated targets and siRNA screens. In addition, immunomodulation and pharmacological manipulation of host functions are being explored in an attempt to widen our therapeutic options. PMID:24401837

  20. Double shell tank waste analysis plan

    SciTech Connect

    Mulkey, C.H.; Jones, J.M.

    1994-12-15

    Waste analysis plan for the double shell tanks. SD-WM-EV-053 is Superseding SD-WM-EV-057.This document provides the plan for obtaining information needed for the safe waste handling and storage of waste in the Double Shell Tank Systems. In Particular it addresses analysis necessary to manage waste according to Washington Administrative Code 173-303 and Title 40, parts 264 and 265 of the Code of Federal Regulations.

  1. Concordance of Bing Doubles and Boundary Genus

    NASA Astrophysics Data System (ADS)

    Livingston, Charles; van Cott, Cornelia A.

    2011-11-01

    Cha and Kim proved that if a knot K is not algebraically slice, then no iterated Bing double of K is concordant to the unlink. We prove that if K has nontrivial signature $\\sigma$, then the n-iterated Bing double of K is not concordant to any boundary link with boundary surfaces of genus less than $2^{n-1}\\sigma$. The same result holds with $\\sigma$ replaced by $2\\tau$, twice the Ozsvath-Szabo knot concordance invariant.

  2. Searches for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Schwingenheuer, Bernhard

    2012-07-01

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of 136Xe. The sensitivities of the different proposals are reviewed.

  3. Decay properties of double heavy baryons

    SciTech Connect

    Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery; Ivanov, Mikhail A.; Koerner, Juergen G.

    2010-08-05

    We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy quark/baryon masses and in the heavy quark symmetry limit which is valid at and close to zero recoil. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit.

  4. Improved double planar probe data analysis technique.

    PubMed

    Ghim Kim, Young-Chul; Hershkowitz, Noah

    2009-03-01

    Plasma electron number density and ion number density in a dc multidipole weakly collisional Ar plasma are measured with a single planar Langmuir probe and a double planar probe, respectively. A factor of two discrepancy between the two density measurements is resolved by applying Sheridan's empirical formula [T. E. Sheridan, Phys. Plasmas 7, 3084 (2000)] for sheath expansion to the double probe data. PMID:19334917

  5. [Veterinary double-monsters historically viewed].

    PubMed

    Baljet, B; Heijke, G C

    1997-01-01

    A large number of duplication monstrosities have been observed in cattle, sheep, pigs, horses, goats, cats and dogs, ever since the publication of the famous woodcut of a swine double monster by J. S. Brant in Basel in 1496, better known as the "wunderbare Sau von Landser im Elsass". Albrecht Dürer also made a woodcut of this double monster in front of the village Landser in 1496. A picture of a deer double monster was published in 1603 by Heinrich Ulrich in Germany. In the monograph De monstrorum causis, natura et differentiis ..., published by the Italian Fortunius Licetus in 1616 pictures of double monsters being half man half dog are found. These fantasy figures have been popular for a long time and were supposed to be really in existence. Apart from these fantasy figures many pictures are known from real veterinary double monsters. U. Aldrovandus described in 1642 in his Monstrorum historia, besides many fantasy figures, also real human and veterinary double monsters and he gave also good pictures of them. In the 19th century examples of veterinary duplication monstrosities were published by I. Geoffroy Saint-Hilaire (1832-37), E. F. Gurlt (1832), W. Vrolik (1840) and C. Taruffi (1881); they proposed also concepts concerning the etiology. In the second volume of his famous handbook of teratology (1907), E. Schwalbe described many veterinary double monsters and discussed the theories of the genesis of congenital malformations. Various theories concerning the genesis of double monsters have been given since Aristotle (384-322 B.C.). ... PMID:11625170

  6. Mexican-American Child Bilingualism: Double Deficit?

    ERIC Educational Resources Information Center

    Dubois, Betty Lou; Fallis, Guadalupe Valdes

    This paper argues that Mexican-American bilinguals are in danger of becoming victims of a double-deficit theory, i.e., they are erroneously considered by some to be deficient in both their languages. An article by Joseph H. Matluck and Betty J. Mace that takes the double-deficit viewpoint is refuted as being damaging to Mexican-American children.…

  7. Conserved currents of double field theory

    NASA Astrophysics Data System (ADS)

    Blair, Chris D. A.

    2016-04-01

    We find the conserved current associated to invariance under generalised diffeomorphisms in double field theory. This can be used to define a generalised Komar integral. We comment on its applications to solutions, in particular to the fundamental string/pp-wave. We also discuss the current in the context of Scherk-Schwarz compactifications. We calculate the current for both the original double field theory action, corresponding to the NSNS sector alone, and for the RR sector.

  8. Wavelength-doubling optical parametric oscillator

    DOEpatents

    Armstrong, Darrell J.; Smith, Arlee V.

    2007-07-24

    A wavelength-doubling optical parametric oscillator (OPO) comprising a type II nonlinear optical medium for generating a pair of degenerate waves at twice a pump wavelength and a plurality of mirrors for rotating the polarization of one wave by 90 degrees to produce a wavelength-doubled beam with an increased output energy by coupling both of the degenerate waves out of the OPO cavity through the same output coupler following polarization rotation of one of the degenerate waves.

  9. The ISAC post-accelerator

    NASA Astrophysics Data System (ADS)

    Laxdal, R. E.; Marchetto, M.

    2014-01-01

    The acceleration chain of the ISAC facility boosts the energy of both radioactive and stable light and heavy ions for beam delivery to both a medium energy area in ISAC-I and a high energy area in ISAC-II. The post-accelerator comprises a 35.4 MHz RFQ to accelerate beams of A/q ≤ 30 from 2 keV/u to 150 keV/u and a post stripper, 106.1 MHz variable energy drift tube linac (DTL) to accelerate ions of A/q ≤ 6 to a final energy between 0.15 MeV/u to 1.5 MeV/u. A 40 MV superconducting linac further accelerates beam from 1.5 MeV/u to energies above the Coulomb barrier. All linacs operate cw to preserve beam intensity.

  10. Post-infectious disease syndrome.

    PubMed Central

    Bannister, B. A.

    1988-01-01

    Many post-infectious syndromes have been recognized in the last 50 years, some following viral infections and others closely related to bacterial disease. The occurrence of prolonged fatigue following an apparent viral illness of varying severity is also well documented. The lack of a recognizable precipitating cause and the tendency for epidemic fatigue to occur among hospital staff led many to believe that the illness may be psychogenic in origin. However, there is serological evidence that some cases may follow enterovirus infections or occasionally delayed convalescence from infectious mononucleosis. Much interesting work is currently in progress relating fatigue to persisting immunological abnormalities, and the development of molecular immunology makes this a most exciting field of research. This paper reviews the evidence for and against a definitive post-viral fatigue syndrome and examines the results of research carried out in the last 50 years. PMID:3074289

  11. The Design and its Verification of the Double Rotor Double Cage Induction Motor

    NASA Astrophysics Data System (ADS)

    Sinha, Sumita; Deb, Nirmal K.; Biswas, Sujit K.

    2016-06-01

    The concept of a double rotor motor presented earlier and its equivalent circuit has been developed, showing a non-linear parameter content. The two rotors (which are recommended to be double cage type for development of high starting torque) can run with equal or unequal speed independently, depending on their individual loading. This paper presents the elaborate design procedure, step-by-step, for the double rotor double cage motor and verifies the designed data with that obtained from three separate tests (compared to two for conventional motor) on a prototype, such that optimum performance can be obtained from the motor.

  12. Leg ischemia post-varicocelectomy

    PubMed Central

    Al-Wahbi, Abdullah M; Elmoukaied, Shaza

    2016-01-01

    Varicocelectomy is the most commonly performed operation for the treatment of male infertility. Many surgical approaches are used as each of them has advantages over the other and is preferred by surgeons. Vascular injury has never been reported as a complication of varicocelectomy apart from testicular artery injury. We present a 36-year-old male who developed leg ischemia post-varicocelectomy due to common femoral artery injury. He was successfully treated by using a vein graft. PMID:27022305

  13. [Post-marketing surveillance studies].

    PubMed

    Pigeot, I; Windeler, J

    2005-05-01

    Approval of a drug on the market is typically considered as the successful endpoint of a long development phase. This often leads to reduced interest in further research for the indication approved, while in contrast the patient's as well as physician's interest in further research increases. This paper discusses the main areas of effectiveness, safety and post-marketing practice regarding sensible study types for the specific area and the potential gain of knowledge. PMID:15887069

  14. Lyme arthritis and post-Lyme disease syndrome.

    PubMed

    Weinstein, Arthur; Britchkov, Michael

    2002-07-01

    In the United States, intermittent or chronic mono- or oligoarthritis, particularly affecting the knee, is the most common manifestation of late Lyme disease (LD). Lyme arthritis (LA) can usually be prevented by early treatment of acute LD. However, the erythema migrans rash may go undetected in children and in the dark skin of African Americans, leading to delayed treatment and a relatively increased incidence in LA. Virtually all untreated patients with LA have high levels of serum immunoglobulin G antibodies, and sometimes low levels of immunoglobulin M antibodies, to Borrelia burgdorferi (Bb) by ELISA and Western blot. These responses may persist for many years after antibiotic treatment, and therefore, serologic results do not accurately distinguish between active or past infection. Most patients with LA respond well to standard courses of antibiotic treatment, but a small percentage have persistent knee synovitis, in some cases possibly related to the triggering of intrasynovial autoimmunity. Other patients develop a syndrome of diffuse arthralgia, myalgia, fatigue, and subjective cognitive difficulty during or soon after LD, which persists despite antibiotic treatment. Patients with this post-treatment, post-LD syndrome were recently studied in a placebo-controlled double-blind antibiotic trial. There was no evidence of Borrelial infection in these patients by culture or detection of Bb DNA in blood or spinal fluid. Furthermore, there was no difference in responsiveness of these patients to a 3-month course of antibiotic compared with placebo treatment. Thus, LA caused by active Bb infection, post-treatment LA with persistent knee synovitis and post-LD syndrome are distinct and distinguishable clinical entities. PMID:12118171

  15. The SPOOKI post production system

    NASA Astrophysics Data System (ADS)

    Beauchemin, M.; Klasa, M.; Fortier, S.; Fortin, F.; Hardy, G.; Pelletier, L.; Edouard, S.; Archambault, B.; Yazidi, H.

    2010-09-01

    The Canadian Meteorological Centre (CMC) delivers a large number of numerical weather prediction products to the various weather offices and clients throughout Canada and abroad. The current post production system was built according to the needs and ideology of the 1980's and it is becoming obsolete with time. Its cumbersome architecture is difficult to maintain and requires a lot of human and computing resources. The "Weather Elements" section of CMC is aware of the problems associated with its maintenance in the long term and has therefore decided to review in depth the whole approach to the operational post production. The analysis of present and future needs have led to the development of an innovative concept in the operational production field inspired by the "Plug and Play" process. SPOOKI (Système de Production Orienté-Objet contennant une Kyrielle d'Informations - Object oriented production system containing a myriad of information) was created in its present form in 2007. It is based on a modular approach where each plug-in component is specialized, reusable and autonomous. These object oriented programming characteristics greatly simplify the maintenance of the system. Particular attention was also given to create a user-friendly system for novice users. An experimental version of SPOOKI is currently running in development mode and an operational one is planned to be implemented in the coming year. The poster presentation will describe SPOOKI, the future CMC operational post production system. Several examples of usage will be shown.

  16. Chen’s Double Eyelid Fold Ratio

    PubMed Central

    Chen, Chen-Chia; Tai, Hao-Chih

    2016-01-01

    Background: Double eyelidplasty can construct palpebral folds and enhance beauty perception for Asians with single eyelids. A new palpebral parameter for the quantitative interpretation of surgical outcomes is proposed on the basis of a photometric study of the altered proportions of Asian eyes after double eyelid operation. Methods: A total of 100 Asian adults with single upper eyelids who were satisfied with the enlarged eyes by operation were included in the study. A retrospective measurement of palpebral parameters in the frontal profile both preoperatively and 6 months postoperatively was performed. The proportions of various parameters in the eyebrow–eye aesthetic unit were calculated and analyzed. Results: Double eyelidplasty can augment the vertical dimension of palpebral fissure by 27.9% increase on average. The vertical ratio of palpebral fissure to the eyebrow–eye unit is augmented by 34.4% increase. The vertical ratio of the subunit below double eyelid fold peak to the unit is augmented by 82.6% increase. Conclusions: Double eyelidplasty can substantially enlarge the vertical dimensions of the eyes of Asians with single eyelids. The eyes are perceived to be larger because of the visually assimilated illusion of the superimposed eyelid fold and the relative proportions of the eyebrow–eye unit. The authors propose using a vertical ratio of the subunit below double eyelid fold peak in the eyebrow–eye unit to measure the visually perceived proportion of the eye in the unit. This ratio can be applied clinically for a quantitative evaluation of the surgical outcome after double eyelidplasty. PMID:27200243

  17. An overview of the progress on double umbilical cord blood transplantation

    PubMed Central

    Sideri, Anastasia; Neokleous, Nikolaos; De La Grange, Philippe Brunet; Guerton, Bernadette; Le Bousse Kerdilles, Marie-Caroline; Uzan, Georges; Peste-Tsilimidos, Corina; Gluckman, Eliane

    2011-01-01

    Umbilical cord blood transplantation has been increasingly used over the past years for both malignant and non-malignant hematologic and other diseases as an alternative to mismatched-related or matched-unrelated bone marrow or peripheral blood hematopoietic stem cell transplantation. A disadvantage of cord blood is its low cell content which limits cord blood transplantation to generally low weight recipients, such as children. Various alternatives have been used to overcome this limitation, including co-infusion of two partially HLA-matched cord blood units. According to Eurocord Registry data, this strategy has been applied in approximately 993 adult patients with hematologic diseases since the first double umbilical cord blood transplantation in 1999. In fact, since 2005, the number of adult patients receiving double umbilical cord blood transplantation has surpassed the number of adults transplanted with single cord blood units. The engraftment rate is comparable for both single and double umbilical cord blood transplantation, although the latter is accompanied by a higher incidence of grade II acute graft-versus-host disease and lower leukemia relapse for patients in first complete remission. In the majority of patients undergoing double umbilical cord blood transplantation, transient chimerism, due to the presence of cells from both donor units early post transplant, is replaced by sustained dominance of one unit from which long-term hematopoiesis is derived. Although the biology and the factors that determine unit dominance have not been clarified, the implication of immune-mediated mechanisms has been reported. Preliminary data have demonstrated the safety of double umbilical cord blood transplantation. Ongoing clinical trials and prolonged follow up of the patients will clarify the immunology and determine the efficacy of this approach. We present here a brief overview of the clinical experience on double umbilical cord blood transplantation and its

  18. Lactoferrin for the Prevention of Post-antibiotic Diarrhoea

    PubMed Central

    McKenzie, Robin; Forti, Jennifer; Conklin, Dawn; Marcinko, Richard; Shrestha, Ruchee; Bellantoni, Michele; Greenough, William B.

    2011-01-01

    Antibiotic-associated diarrhoea (AAD) is a common cause of morbidity and mortality. Older individuals in long-term care facilities are particularly vulnerable due to multisystem illnesses and the prevailing conditions for nosocomial infections. Lactoferrin, an antimicrobial protein in human breastmilk, was tested to determine whether it would prevent or reduce AAD, including Clostridium difficile in tube-fed long-term care patients. Thirty patients were enrolled in a randomized double-blind study, testing eight weeks of human recombinant lactoferrin compared to placebo for the prevention of antibiotic-associated diarrhoea in long-term care patients. Fewer patients in the lactoferrin group experienced diarrhoea compared to controls (p=0.023). Based on the findings, it is concluded that human lactoferrin may reduce post-antibiotic diarrhoea. PMID:22283027

  19. Quality of Movement for Athletes Six Months Post ACL Reconstruction

    PubMed Central

    deMille, Polly; Nguyen, Joseph; Brown, Allison; Do, Huong; Selvaggio, Elizabeth; Chiaia, Theresa

    2016-01-01

    Objectives: Anterior cruciate ligament (ACL) injury prevention programs evaluate quality of movement (QM) to identify and correct high-risk movement patterns. However, return to play (RTP) decisions post-ACL reconstruction (ACLR) are often based on non-sport relatedquantitative measures such as isokinetic tests and/or time from surgery, with six months post-ACLR being a common expectation for RTP. The purpose of this study was to evaluate whether athletes are ready to RTP 6 months post ACLR using a QM assessment (QMA). Methods: A QMA including nine dynamic tasks (squat, single leg [SL] stance, step down, SL squat, jump in place, side to side jump, broad jump, hop to opposite, SL hop) progressing from double- to single-limb vertical and horizontal movements was administered to 136 athletes at five to seven months post-ACLR. Tasks were viewed from the frontal and sagittal planes by a physical therapist and performance specialist. Movements were evaluated live for risk factors associated with ACL injury (strategy, depth, control, symmetry, and alignment). The proportion of patients exhibiting risky movement patterns for each task was calculated. Fisher’s Exact test was used to determine if there were differences in movement patterns between males and females. Results: The proportion of patients demonstrating risky movement patterns for a task ranged from 48% to 100%. All 136 patients exhibited risky movement patterns for at least one task and 60% of patients displayed risky movement patterns in five or more of the nine tasks. Rates of risky movement patterns were not different between males and females for all tasks (P>0.1 for all tasks). Conclusion: Six months has been cited as a probable time for RTP post-ACLR; thus this is the expectation of the athlete. Our data show that athletes demonstrate multiple QM patterns associated with initial ACL injury, as well as 2nd injury at five to seven months post-operatively. Altered movement patterns evident in tasks as

  20. 75 FR 78778 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... informs the public that an appeal of the closing of the Holmes Mill (Kentucky) Post Office has been filed... of the closing of the Holmes Mill Post Office in Holmes Mill, Kentucky. The petition, which was...

  1. 42 CFR 124.604 - Posted notice.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... facility shall post notices, which the Secretary supplies in English and Spanish, in appropriate areas of... other than English or Spanish, the facility shall translate the notice into that language and post...

  2. 76 FR 44385 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... informs the public that an appeal of the closing of the Peach Orchard, Arkansas post office has been filed... review of the closing of the Peach Orchard, Arkansas post office. The petition, which was filed...

  3. 76 FR 9056 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ... informs the public that an appeal of the closing of the Lincoln Branch Post Office in Mansfield, Ohio, has... for review of the closing of the Lincoln Branch Post Office in Mansfield, Ohio. The petition,...

  4. Post-Traumatic Stress Disorder (PDQ)

    MedlinePlus

    ... with post-traumatic stress need early treatment with methods that are used to treat other trauma victims. ... symptoms of post-traumatic stress. The crisis intervention method aims to relieve distress and help the patient ...

  5. Schooling in a Post-Industrial Society

    ERIC Educational Resources Information Center

    Doll, William, E. Jr.

    1978-01-01

    Explores the coming post-industrial society for its possible effects on the education-schooling syndrome we now have. Emphasizes the sociological writings of the "father" of post-industrialism, Daniel Bell. (Author/RK)

  6. 77 FR 3806 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document... Station post office in Yerington, Nevada. The first petition for review received December 28, 2011,...

  7. 76 FR 53984 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... informs the public that an appeal of the closing of the Prairie Hill, Texas post office has been filed. It... for review of the Postal Service's determination to close the Prairie Hill post office in Prairie...

  8. 46 CFR 171.109 - Watertight floors in double bottoms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Watertight floors in double bottoms. 171.109 Section 171... Watertight floors in double bottoms. If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near...

  9. 46 CFR 171.109 - Watertight floors in double bottoms.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Watertight floors in double bottoms. 171.109 Section 171... Watertight floors in double bottoms. If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near...

  10. 46 CFR 171.109 - Watertight floors in double bottoms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Watertight floors in double bottoms. 171.109 Section 171... Watertight floors in double bottoms. If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near...

  11. 46 CFR 171.109 - Watertight floors in double bottoms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Watertight floors in double bottoms. 171.109 Section 171... Watertight floors in double bottoms. If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near...

  12. 46 CFR 171.109 - Watertight floors in double bottoms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Watertight floors in double bottoms. 171.109 Section 171... Watertight floors in double bottoms. If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near...

  13. The First SLR Double-Difference Baseline

    NASA Astrophysics Data System (ADS)

    Svehla, Drazen; Haagmans, Roger; Floberghagen, Rune; Cacciapuoti, Luigi; Sierk, Bernd; Kirchner, Georg; Rodriguez, Jose; Wilkinson, Matthew; Sherwood, Rob; Appleby, Graham

    2013-04-01

    We introduce the SLR double-difference approach of space geodesy. With real and simulated SLR measurements it is shown how common SLR biases are removed by forming SLR double-differences, i.e. station range biases, common retro-reflector effects and orbit errors (GNSS) for baselines up to e.g. 5000 km. In this way we obtain SLR observables of utmost precision and accuracy. We show how remaining noise in the SLR measurements nicely averages out, leading to orbit-free and bias-free estimation of station coordinates, local ties between different space geodesy techniques and precise comparison of optical/microwave tropospheric effects. It shall be noted that SLR scale is preserved by double-differencing. When ETALON and LAGEOS satellites are observed by SLR, any orbit error propagates directly into estimated station coordinates. However, by forming differences between two satellites and two ground stations this orbit error can be eliminated. Both satellites need to be observed quasi-simultaneously in the same tracking sessions in order that station range bias and common retro-reflector effects are removed by differencing. When SLR measurements from GRZL and HERL SLR stations are taken to GLONASS and LAGEOS satellites and processed in double-difference mode, clear common orbit errors are visible in the SLR residuals from both stations. The same stands for small range biases that are visible between the consecutive observing sessions and are removed by forming SLR baselines. Longer SLR passes reveal other interesting systematic effects common to both stations at mm-level. An error in the order of 4-6 cm RMS was introduced to GNSS orbits, however the effect on station coordinates in negligible over such a short SLR baseline. We show how with just one-two SLR double-difference passes one can estimate station coordinates at mm-level. When in parallel, both GNSS satellites are observed with microwave measurements, one can estimate very accurate local ties by comparing (or

  14. Double-difference adjoint seismic tomography

    NASA Astrophysics Data System (ADS)

    Yuan, Yanhua O.; Simons, Frederik J.; Tromp, Jeroen

    2016-06-01

    We introduce a `double-difference' method for the inversion for seismic wavespeed structure based on adjoint tomography. Differences between seismic observations and model predictions at individual stations may arise from factors other than structural heterogeneity, such as errors in the assumed source-time function, inaccurate timings, and systematic uncertainties. To alleviate the corresponding nonuniqueness in the inverse problem, we construct differential measurements between stations, thereby reducing the influence of the source signature and systematic errors. We minimize the discrepancy between observations and simulations in terms of the differential measurements made on station pairs. We show how to implement the double-difference concept in adjoint tomography, both theoretically and in practice. We compare the sensitivities of absolute and differential measurements. The former provide absolute information on structure along the ray paths between stations and sources, whereas the latter explain relative (and thus higher-resolution) structural variations in areas close to the stations. Whereas in conventional tomography a measurement made on a single earthquake-station pair provides very limited structural information, in double-difference tomography one earthquake can actually resolve significant details of the structure. The double-difference methodology can be incorporated into the usual adjoint tomography workflow by simply pairing up all conventional measurements; the computational cost of the necessary adjoint simulations is largely unaffected. Rather than adding to the computational burden, the inversion of double-difference measurements merely modifies the construction of the adjoint sources for data assimilation.

  15. On models of double porosity poroelastic media

    NASA Astrophysics Data System (ADS)

    Boutin, Claude; Royer, Pascale

    2015-12-01

    This paper focuses on the modelling of fluid-filled poroelastic double porosity media under quasi-static and dynamic regimes. The double porosity model is derived from a two-scale homogenization procedure, by considering a medium locally characterized by blocks of poroelastic Biot microporous matrix and a surrounding system of fluid-filled macropores or fractures. The derived double porosity description is a two-pressure field poroelastic model with memory and viscoelastic effects. These effects result from the `time-dependent' interaction between the pressure fields in the two pore networks. It is shown that this homogenized double porosity behaviour arises when the characteristic time of consolidation in the microporous domain is of the same order of magnitude as the macroscopic characteristic time of transient regime. Conversely, single porosity behaviours occur when both timescales are clearly distinct. Moreover, it is established that the phenomenological approaches that postulate the coexistence of two pressure fields in `instantaneous' interaction only describe media with two pore networks separated by an interface flow barrier. Hence, they fail at predicting and reproducing the behaviour of usual double porosity media. Finally, the results are illustrated for the case of stratified media.

  16. Plans for Double Shell Experiments on NIF

    NASA Astrophysics Data System (ADS)

    Montgomery, D. S.; Daughton, W. S.; Gunderson, M. A.; Simakov, A. N.; Wilson, D. C.; Watt, R. G.; Kline, J. L.; Hayes, A. C.; Herrmann, H. W.; Boswell, M.; Danly, C. R.; Merrill, F. E.; Batha, S. H.; Amendt, P. A.; Milovich, J. L.; Robey, H. F.

    2015-11-01

    Double-shells are an alternative approach to achieving indirect drive ignition. These targets consist of a low-Z ablatively-driven outer shell that impacts a high-Z inner shell filled with DT fuel. In contrast to single-shell designs, double-shell targets burn the fuel via volume ignition, albeit with a lower gain. While double-shell capsules are complicated to fabricate, their design includes several beneficial metrics such as a low convergence pusher (C.R. < 10), low implosion speed (~ 250 km/s), a simple few-ns laser drive in a vacuum hohlraum, less sensitivity to hohlraum asymmetries, and low expected laser-plasma instabilities. We present preliminary double-shell capsule designs for NIF using a cryogenic gas DT fill which are optimized for yield and minimized for fall-line mix. Challenges will be discussed, as well as uncertainties and trade-offs in the physics issues compared to single-shells. A development path for double-shell experiments on NIF will be presented. Work performed under the auspices of DOE by LANL under contract DE-AC52-06NA25396.

  17. Re-naming D Double Prime

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    1999-01-01

    "Knowledge about the dynamics of the D double prime region is a key to unlock some fundamental mysteries of the Earth heat engine which governs a wide range of global geophysical processes from tectonics to geodynamo." This benign sentence makes complete sense to many geophysicists. But for many others, it makes sense all except the odd nomenclature "D double prime". One knows about the crust, upper and lower mantle, outer and inner core, but where is the D double prime region? What meaning does it try to convey? Where is D prime region, or D, or A, B, C regions for that matter, and are there higher-order primes? How does such an odd name come about anyway? D double prime, or more "simply" D", is a generic designation given to the thin shell, about 200 km thick, of the lowermost mantle just above the core-mantle boundary inside the Earth. Incidentally, whether D" is "simpler" than "D double prime" depends on whether you are pronouncing it or writing/typing it; and D" can be confusing to readers in distinguishing quotation marks (such as in the above sentences) and second derivatives, and to word processors in spelling check and indexing.

  18. The doubling of stellar black hole nuclei

    NASA Astrophysics Data System (ADS)

    Kazandjian, Mher V.; Touma, J. R.

    2013-04-01

    It is strongly believed that Andromeda's double nucleus signals a disc of stars revolving around its central supermassive black hole on eccentric Keplerian orbits with nearly aligned apsides. A self-consistent stellar dynamical origin for such apparently long-lived alignment has so far been lacking, with indications that cluster self-gravity is capable of sustaining such lopsided configurations if and when stimulated by external perturbations. Here, we present results of N-body simulations which show unstable counter-rotating stellar clusters around supermassive black holes saturating into uniformly precessing lopsided nuclei. The double nucleus in our featured experiment decomposes naturally into a thick eccentric disc of apo-apse aligned stars which is embedded in a lighter triaxial cluster. The eccentric disc reproduces key features of Keplerian disc models of Andromeda's double nucleus; the triaxial cluster has a distinctive kinematic signature which is evident in Hubble Space Telescope observations of Andromeda's double nucleus, and has been difficult to reproduce with Keplerian discs alone. Our simulations demonstrate how the combination of an eccentric disc and a triaxial cluster arises naturally when a star cluster accreted over a preexisting and counter-rotating disc of stars drives disc and cluster into a mutually destabilizing dance. Such accretion events are inherent to standard galaxy formation scenarios. They are here shown to double stellar black hole nuclei as they feed them.

  19. Double Engine for a Nebula

    NASA Astrophysics Data System (ADS)

    2009-08-01

    ESO has just released a stunning new image of a field of stars towards the constellation of Carina (the Keel). This striking view is ablaze with a flurry of stars of all colours and brightnesses, some of which are seen against a backdrop of clouds of dust and gas. One unusual star in the middle, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fuelling the star's remarkable nebula. The new image, showing a very rich field of stars towards the Carina arm of the Milky Way, is centred on the star HD 87643, a member of the exotic class of B[e] stars [1]. It is part of a set of observations that provide astronomers with the best ever picture of a B[e] star. The image was obtained with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the 2400-metre-high La Silla Observatory in Chile. The image shows beautifully the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. A team of astronomers, led by Florentin Millour, has studied the star HD 87643 in great detail, using several of ESO's telescopes. Apart from the WFI, the team also used ESO's Very Large Telescope (VLT) at Paranal. At the VLT, the astronomers used the NACO adaptive optics instrument, allowing them to obtain an image of the star free from the blurring effect of the atmosphere. To probe the object further, the team then obtained an image with the Very Large Telescope Interferometer (VLTI). The sheer range of this set of observations

  20. 76 FR 59451 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... informs the public that an appeal of the closing of the Coyote, New Mexico post office has been filed. It... Postal Service's determination to close the Coyote post office in Coyote, New Mexico. The petition was filed by Manuelita Trujillo on behalf of the Concerned Citizens of the Coyote Post Office...

  1. 49 CFR 238.213 - Corner posts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or its supporting car body structure. (3) Prior to or during structural deformation, each corner post... supporting car body structure. (4) Prior to or during structural deformation, the two posts in combination... deformation of either the post or its supporting car body structure. (2) For purposes of this paragraph...

  2. 49 CFR 238.213 - Corner posts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... or its supporting car body structure. (3) Prior to or during structural deformation, each corner post... supporting car body structure. (4) Prior to or during structural deformation, the two posts in combination... deformation of either the post or its supporting car body structure. (2) For purposes of this paragraph...

  3. 49 CFR 238.213 - Corner posts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... or its supporting car body structure. (3) Prior to or during structural deformation, each corner post... supporting car body structure. (4) Prior to or during structural deformation, the two posts in combination... deformation of either the post or its supporting car body structure. (2) For purposes of this paragraph...

  4. 49 CFR 238.213 - Corner posts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or its supporting car body structure. (3) Prior to or during structural deformation, each corner post... supporting car body structure. (4) Prior to or during structural deformation, the two posts in combination... deformation of either the post or its supporting car body structure. (2) For purposes of this paragraph...

  5. 49 CFR 238.213 - Corner posts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... or its supporting car body structure. (3) Prior to or during structural deformation, each corner post... supporting car body structure. (4) Prior to or during structural deformation, the two posts in combination... deformation of either the post or its supporting car body structure. (2) For purposes of this paragraph...

  6. Post-Colonial Theory and Action Research

    ERIC Educational Resources Information Center

    Parsons, Jim B.; Harding, Kelly J.

    2011-01-01

    This essay explores connections between post-colonial theory and action research. Post-colonial theory is committed to addressing the plague of colonialism. Action research, at its core, promises to problematize uncontested "colonial" hegemonies of any form. Both post-colonial theory and action research engage dialogic, critically reflective and…

  7. 76 FR 72454 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Elmo, Missouri post office has been filed. It... received a petition for review of the Postal Service's determination to close the Elmo post office in...

  8. 76 FR 76443 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... COMMISSION Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Greeley, Iowa post office has been filed. It... received a petition for review of the Postal Service's determination to close the Greeley post office...

  9. 76 FR 68232 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Ogden, Arkansas post office has been filed. It... received a petition for review of the Postal Service's determination to close the Ogden post office...

  10. 76 FR 76444 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Holland, Iowa post office has been filed. It... received a petition for review of the Postal Service's determination to close the Holland post office...

  11. 75 FR 4429 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Sundance, CO, post office has been filed. It... closing of the Sundance post office located in Steamboat Springs, Colorado 80487. The appeal was...

  12. 76 FR 72456 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Scottville, Illinois post office has been filed... received a petition for review of the Postal Service's determination to close the Scottville post office...

  13. 76 FR 76447 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Miller, Nebraska post office has been filed. It... received a petition for review of the Postal Service's determination to close the Miller post office...

  14. 76 FR 54511 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Lake Creek, Texas post office has been filed. It... Service's determination to close the Lake Creek post office in Lake Creek, Texas. The petitions were...

  15. 75 FR 70956 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Lancaster, Tennessee post office has been filed... for review of the closing of the Lancaster Post Office located in Lancaster, Tennessee. The...

  16. 76 FR 54264 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Enloe, Texas post office has been filed. It... Postal Service's determination to close the Enloe post office in Enloe, Texas. The petitions were...

  17. 76 FR 76451 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Nixon, Nevada post office has been filed. It... received a petition for review of the Postal Service's determination to close the Nixon post office...

  18. 76 FR 78954 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-20

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Milan, Kansas post office has been filed. It... close the Milan post office in Milan, Kansas. The petition for review was filed by Michele...

  19. 76 FR 72457 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Morgan City, Mississippi post office has been... two petitions for review of the Postal Service's determination to close the Morgan City post office...

  20. 76 FR 76445 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Mountain City, Nevada post office has been filed... for review of the Postal Service's determination to close the Mountain City post office in...

  1. 76 FR 63332 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Evansdale, Iowa post office has been filed. It... received a petition for review of the Postal Service's determination to close the Evansdale post office...

  2. 76 FR 72453 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Waverly, Washington post office has been filed. It... received a petition for review of the Postal Service's determination to close the Waverly post office...

  3. 76 FR 58058 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Meridian, New York post office has been filed. It... Postal Service's determination to close the Meridian post office in Meridian, New York. The petition...

  4. 76 FR 76446 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Home, Kansas post office has been filed. It... for review of the Postal Service's determination to close the Home post office in Home, Kansas....

  5. 77 FR 5582 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Balm, Florida post office has been filed. It... Commission received a petition for review of the Postal Service's determination to close the Balm post...

  6. 76 FR 76449 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Spring Dale, West Virginia post office has been... four petitions for review of the Postal Service's determination to close the Spring Dale post office...

  7. 76 FR 76448 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Viola, Idaho post office has been filed. It... for review of the Postal Service's determination to close the Viola post office in Viola, Idaho....

  8. 76 FR 80986 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the McCallsburg, Iowa post office has been filed. It... close the McCallsburg post office in McCallsburg, Iowa. The petition for review was filed by...

  9. 76 FR 55426 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Ottosen, Iowa post office has been filed. It... for review of the Postal Service's determination to close the Ottosen post office in Ottosen,...

  10. 76 FR 54265 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the West Elkton, Ohio post office has been filed. It... Postal Service's determination to close the West Elkton post office in West Elkton, Ohio. The...

  11. 76 FR 68231 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Ferguson, Iowa post office has been filed. It... received a petition for review of the Postal Service's determination to close the Ferguson post office...

  12. 76 FR 72458 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Pace, Mississippi post office has been filed. It... for review of the Postal Service's determination to close the Pace post office in Pace,...

  13. 76 FR 55425 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Watson, Alabama post office has been filed. It... for review of the Postal Service's determination to close the Watson post office in Watson,...

  14. 76 FR 78702 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-19

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Sherwood, Michigan post office has been filed. It... close the Sherwood post office in Sherwood, Michigan. The petition for review was filed by...

  15. 75 FR 15753 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Crescent Lake (Oregon)Post Office ZIP Code 97425... of the closing of the Crescent Lake Post Office, Crescent Lake, Oregon 97425. The appeal was...

  16. 76 FR 66337 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Ruth, Mississippi, post office has been filed. It... received a petition for review of the Postal Service's determination to close the Ruth post office in...

  17. 36 CFR 261.51 - Posting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of the order imposing each prohibition in...

  18. 10 CFR 20.1902 - Posting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... HIGH RADIATION AREA.” (d) Posting of airborne radioactivity areas. The licensee shall post each airborne radioactivity area with a conspicuous sign or signs bearing the radiation symbol and the words “CAUTION, AIRBORNE RADIOACTIVITY AREA” or “DANGER, AIRBORNE RADIOACTIVITY AREA.” (e) Posting of areas...

  19. 10 CFR 20.1902 - Posting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... HIGH RADIATION AREA.” (d) Posting of airborne radioactivity areas. The licensee shall post each airborne radioactivity area with a conspicuous sign or signs bearing the radiation symbol and the words “CAUTION, AIRBORNE RADIOACTIVITY AREA” or “DANGER, AIRBORNE RADIOACTIVITY AREA.” (e) Posting of areas...

  20. 10 CFR 20.1902 - Posting requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... HIGH RADIATION AREA.” (d) Posting of airborne radioactivity areas. The licensee shall post each airborne radioactivity area with a conspicuous sign or signs bearing the radiation symbol and the words “CAUTION, AIRBORNE RADIOACTIVITY AREA” or “DANGER, AIRBORNE RADIOACTIVITY AREA.” (e) Posting of areas...

  1. 10 CFR 20.1902 - Posting requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... HIGH RADIATION AREA.” (d) Posting of airborne radioactivity areas. The licensee shall post each airborne radioactivity area with a conspicuous sign or signs bearing the radiation symbol and the words “CAUTION, AIRBORNE RADIOACTIVITY AREA” or “DANGER, AIRBORNE RADIOACTIVITY AREA.” (e) Posting of areas...

  2. 10 CFR 20.1902 - Posting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... HIGH RADIATION AREA.” (d) Posting of airborne radioactivity areas. The licensee shall post each airborne radioactivity area with a conspicuous sign or signs bearing the radiation symbol and the words “CAUTION, AIRBORNE RADIOACTIVITY AREA” or “DANGER, AIRBORNE RADIOACTIVITY AREA.” (e) Posting of areas...

  3. Programs Handle PostScript Files

    NASA Technical Reports Server (NTRS)

    Choi, Diana; Yip, David

    1992-01-01

    PSTOOLS is package of four programs to interpret and format files in PostScript language. PSIRIS, PSMATRIX, and PSTEK interpret PostScript language and send graphical results to device. PSPRETTY formats PostScript files by appropriately indenting procedures and code delimited by "saves" and "restores". Written in C.

  4. 36 CFR 261.51 - Posting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy...

  5. Post-Process "Pedagogy": A Philosophical Exercise.

    ERIC Educational Resources Information Center

    Breuch, Lee-Ann M. Kastman

    2002-01-01

    Notes post-process theories of composition instruction suggest that process is no longer an adequate explanation of the writing act. Explains how post-process theory can contribute to composition pedagogy. Argues that post-process theory encourages educators to reexamine the definition of writing as an activity rather than a body of knowledge,…

  6. 76 FR 60947 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Jordanville, New York post office has been filed... petition for review of the Postal Service's determination to close the Jordanville post office...

  7. 76 FR 65545 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Agate, Colorado post office has been filed. It... received a petition for review of the Postal Service's determination to close the Agate post office...

  8. 77 FR 1754 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the St. Anthony, Iowa post office has been filed. It... determination to close the St. Anthony post office in St. Anthony, Iowa. The petition for review was filed...

  9. 76 FR 71084 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Orchard, Iowa post office has been filed. It... received two petitions for review of the Postal Service's determination to close the Orchard post office...

  10. 76 FR 47614 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Pilot Grove, Iowa post office has been filed. It... of the Postal Service's determination to close the post office in Pilot Grove, Iowa. The...

  11. 76 FR 28103 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Gywnedd, Pennsylvania post office has been filed... of the Gwynedd, Pennsylvania post office. The petition, which was filed by Christina...

  12. 37 CFR 2.81 - Post publication.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Post publication. 2.81 Section 2.81 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Publication and Post Publication § 2.81 Post publication....

  13. 76 FR 67498 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Venice, California post office has been filed. It... close the Venice post office in Venice, California. The petition for review was filed online on...

  14. 77 FR 4380 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Ponce de Leon, Missouri post office has been filed... de Leon Post Office in Ponce de Leon, Missouri. The petition for review received January 6, 2012,...

  15. 76 FR 75918 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Lanagan, Missouri post office has been filed. It... received a petition for review of the Postal Service's determination to close the Lanagan post office...

  16. 76 FR 70174 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-10

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Amoret, Missouri post office has been filed. It... received a petition for review of the Postal Service's determination to close the Amoret post office...

  17. 37 CFR 2.81 - Post publication.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Post publication. 2.81 Section 2.81 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Publication and Post Publication § 2.81 Post publication....

  18. 76 FR 60946 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the North Canton, Connecticut post office has been... petition for review of the Postal Service's determination to close the North Canton post office in...

  19. 48 CFR 752.7029 - Post privileges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Post privileges. 752.7029... FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of USAID Contract Clauses 752.7029 Post privileges. For use in all USAID non-commercial contracts involving performance overseas. Post...

  20. 48 CFR 752.7029 - Post privileges.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Post privileges. 752.7029... FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of USAID Contract Clauses 752.7029 Post privileges. For use in all USAID non-commercial contracts involving performance overseas. Post...