Now showing items 324-343 of 579

  • Observation of backflow in the switch-on dynamics of a hybrid aligned nematic 

    Jewell, Sharon A.; Sambles, J. Roy (American Institute of Physics, 2004)
    The optical convergent-beam technique is used to measure, in 0.3 ms steps, the response of the director in a 4.6-µm-thick ZLI-2293 filled hybrid aligned nematic cell when a 10 kHz, 7 Vrms ac voltage is applied to the cell. ...
  • Observation of ferromagnetic resonance in the time domain 

    Hicken, R.J.; Wu, J. (American Institute of Physics, 1999)
    Optical pump–probe spectroscopy has been used to observe damped ferromagnetic resonance (FMR) oscillations in thin film Fe samples. The FMR was pumped by magnetic field pulses generated by an optically triggered photoconductive ...
  • Observation of negative-frequency waves in a water tank: A classical analogue to the Hawking effect? 

    Rousseaux, Germain; Mathis, Christian; Maissa, Philippe; Philbin, Thomas G.; Leonhardt, Ulf (Institute of Physics, 2008)
    The conversion of positive-frequency waves into negative-frequency waves at the event horizon is the mechanism at the heart of the Hawking radiation of black holes. In black-hole analogues, horizons are formed for waves ...
  • Observation of T2-like coherent optical phonons in epitaxial Ge2Sb2Te5/GaSb(001) films 

    Shalini, Ashawaraya; Liu, Y.; Al-Jarah, Uday Ali Sabeeh; Srivastava, G.P.; Wright, C. David; Katmis, F.; Braun, W.; Hicken, R.J. (Nature Publishing Group, 2013)
    The phonon spectrum of Ge2Sb2Te5 is a signature of its crystallographic structure and underlies the phase transition process used in memory applications. Epitaxial materials allow coherent optical phonons to be studied in ...
  • Observation of the full 12-hour-long transit of the exoplanet HD80606b: Warm-Spitzer photometry and SOPHIE spectroscopy 

    Hebrard, G.; Desert, J.-M.; Diaz, R.F.; Boisse, I.; Bouchy, F.; Lecavelier des Etangs, A.; Moutou, C.; Ehrenreich, D.; Arnold, L.; Bonfils, X.; Delfosse, X.; Desort, M.; Eggenberger, A.; Forveille, T.; Gregorio, J.; Lagrange, A.-M.; Lovis, C.; Pepe, F.; Perrier, C.; Pont, F.; Queloz, D.; Santerne, A.; Santos, N.C.; Segransan, D.; Sing, David K.; Udry, S.; Vidal-Madjar, A. (EDP Sciences for European Southern Observatory (ESO), 2010)
    We present new observations of a transit of the 111.4-day-period exoplanet HD 80606b. Due to this long orbital period and to the orientation of the eccentric orbit (e = 0.9), HD 80606b's transits last for about 12 hours. ...
  • Observation of thickness dependence of magnetic surface anisotropy in ultrathin amorphous films. 

    Hicken, R.J.; Rado, G.T.; Xiao, G.; Chien, C.L. (American Physical Society, 1990)
    Ferromagnetic resonance (FMR) and SQUID magnetometry measurements have been made on multilayers of amorphous Fe70B30/Ag. The dependence of the magnetic surface anisotropy constant Ks on the magnetic layer thickness 2L has ...
  • An Observational Perspective of Transitional Disks 

    Espaillat, C; Muzerolle, J; Najita, J; Andrews, S; Zhu, Z; Calvet, Nuria; Kraus, Stefan; Hashimoto, J; Kraus, Adam; D Alessio, P (arXiv.org, 2014-02-27)
    Transitional disks are objects whose inner disk regions have undergone substantial clearing. The Spitzer Space Telescope produced detailed spectral energy distributions (SEDs) of transitional disks that allowed us to infer ...
  • Observed luminosity spread in young clusters and Fu Ori stars: a unified picture 

    Baraffe, I.; Vorobyov, Eduard I.; Chabrier, G. (American Astronomical Society, 2012)
    The idea that non-steady accretion during the embedded phase of protostar evolution can produce the observed luminosity spread in the Herzsprung–Russell diagram (HRD) of young clusters has recently been called into question. ...
  • On close-in magnetized star-planet interactions 

    Strugarek, Antoine; Brun, Allan Sacha; Matt, Sean P. (French Society of Astronomy and Astrophysics, 2012)
    We present 2D magnetohydrodynamic simulations performed with the PLUTO code to model magnetized star-planet interactions. We study two simple scenarios of magnetized star-planet interactions: the unipolar and dipolar ...
  • On the creation of future probabilistic design weather years from UKCP09 

    Eames, Matthew E.; Kershaw, Tristan; Coley, David (SAGE Publications, 2011)
    Weather data are used extensively by building scientists and engineers to study the performance of their designs, help compare design alternatives and ensure compliance with building regulations. Given a changing climate, ...
  • On the effects of clouds and hazes in the atmospheres of hot Jupiters: semi-analytical temperature-pressure profiles 

    Heng, Kevin; Hayek, W.; Pont, F.; Sing, David K. (Oxford University Press on behalf of the Royal Astronomical Society, 2011)
    Motivated by the work of Guillot, we present a semi-analytical formalism for calculating the temperature–pressure profiles in hot Jovian atmospheres which includes the effects of clouds/hazes and collision-induced absorption. ...
  • On the mechanism of charge transport in pentacene 

    van Laarhoven, Hendrik A.; Flipse, Cees F. J.; Koeberg, Mattijs; Bonn, Mischa; Hendry, Euan; Orlandi, G.; Jurchescu, O. D.; Palstra, T. T. M.; Troisi, A. (American Institute of Physics, 2008)
    Terahertz transient conductivity measurements are performed on pentacene single crystals, which directly demonstrate a strong coupling of charge carriers to low frequency molecular motions with energies centered around 1.1 ...
  • On the Nature of the Herbig B[e] Star Binary System V921 Scorpii: Discovery of a Close Companion and Relation to the Large-scale Bipolar Nebula 

    Kraus, Stefan; Calvet, Nuria; Hartmann, Lee; Hofmann, Karl-Heinz; Kreplin, Alexander; Monnier, John D.; Weigelt, Gerd (IOP Publishing for American Astronomical Society, 2012)
    Belonging to the group of B[e] stars, V921 Scorpii is associated with a strong infrared excess and permitted and forbidden line emission, indicating the presence of low- and high-density circumstellar gas and dust. Many ...
  • On the Nature of the Herbig B[e] Star Binary System V921 Scorpii: Geometry and Kinematics of the Circumprimary Disk on Sub-AU Scales 

    Kraus, Stefan; Calvet, Nuria; Hartmann, Lee; Hofmann, Karl-Heinz; Kreplin, Alexander; Monnier, John D.; Weigelt, Gerd (IOP Publishing for American Astronomical Society, 2012)
    V921 Scorpii is a close binary system (separation 0farcs025) showing the B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which might have been shaped by episodic mass-loss events, possibly triggered ...
  • On the relative importance of different microphysics on the D-type expansion of galactic H ii regions 

    Haworth, Thomas; Harries, Tim J.; Acreman, David M.; Bisbas, TG (Oxford University Press for Royal Astronomical Society, 2015-11-01)
    Radiation hydrodynamics (RHD) simulations are used to study many astrophysical phenomena; however, they require the use of simplified radiation transport and thermal prescriptions to reduce computational cost. In this ...
  • One dimensional electromagnetic waves on flat surfaces 

    Horsley, S.A.R.; Hooper, Ian R. (Institute of Physics Publishing, 2014-10-29)
    We show that one-dimensional electromagnetic waves can be constrained to propagate along a join between two thin sheets when one surface supports transverse magnetic polarized surface waves and the other supports transverse ...
  • One-dimensional Coulomb problem in Dirac materials 

    Downing, C.A.; Portnoi, M.E. (American Physical Society, 2014)
    We investigate the one-dimensional Coulomb potential with application to a class of quasirelativistic systems, so-called Dirac-Weyl materials, described by matrix Hamiltonians. We obtain the exact solution of the shifted ...
  • One-dimensional Van Hove polaritons 

    Arnardottir, K.B.; Kyriienko, O.; Portnoi, M.E.; Shelykh, I.A. (American Physical Society, 2013)
    We study the light-matter coupling of microcavity photons and an interband transition in a one-dimensional (1D) nanowire. Due to the Van Hove singularity in the density of states, resulting in a resonant character of the ...
  • One-way diffraction grating 

    Lockyear, Matthew J.; Hibbins, Alastair P.; White, Kevin R.; Sambles, J. Roy (American Physical Society, 2006)
    Diffraction gratings are elementary tools for much of optics and spectroscopy. Here, at microwave frequencies, we provide a new perspective on these fundamental structures. A transmission diffraction grating is presented ...
  • Operating characteristics of a semiconducting polymer laser pumped by a microchip laser 

    Turnbull, G. A.; Andrew, P.; Barnes, William L.; Samuel, I. D. W. (American Institute of Physics, 2003)
    We report the demonstration of a compact, all-solid-state polymer laser system featuring a microchip laser as the pump source. The laser was configured as a surface-emitting, two-dimensional distributed feedback laser, ...