Now showing items 144-163 of 729

  • Direct observation of negative-index microwave surface waves. 

    Dockrey, JA; Horsley, SA; Hooper, Ian R.; Sambles, JR; Hibbins, Alastair P. (Nature Publishing Group: Open Access Journals - Option C, 2016-02-23)
    Waves propagating in a negative-index material have wave-front propagation (wavevector, k) opposite in direction to that of energy flow (Poynting vector, S). Here we present an experimental realisation at microwave frequencies ...
  • Direct Optical Quantification of Backflow in a 90° Twisted Nematic Cell 

    Smith, N. J.; Tillin, M. D.; Sambles, J. Roy (American Physical Society, 2002)
    Optical guided mode observations of the transient director profile (optical tensor distribution) during the relaxation of a 90° twisted nematic cell directly reveals backflow. In the first 6 ms of the relaxation process, ...
  • Directly observing continuum emission from self-gravitating spiral waves 

    Hall, C; Forgan, D; Rice, K; Harries, TJ; Klaassen, PD; Biller, B (Oxford University Press (OUP) / Royal Astronomical Society, 2016)
    We use a simple, self-consistent, self-gravitating semi-analytic disc model to conduct an examination of the parameter space in which self-gravitating discs may exist. We then use Monte-Carlo radiative transfer to generate ...
  • Discovery of a bright eclipsing cataclysmic variable 

    Sing, David K.; Green, E.M.; Howell, S.B.; Holberg, J.B.; Lopez-Morales, M.; Shaw, J.S.; Schmidt, G.D. (EDP Sciences for European Southern Observatory (ESO), 2007)
    Aims.We report on the discovery of J0644+3344 , a bright, deeply-eclipsing cataclysmic variable (CV) binary. Methods.Optical photometric and spectroscopic observations were obtained to determine the nature and characteristics ...
  • Discovery of Seven Companions to Intermediate Mass Stars with Extreme Mass Ratios in the Scorpius-Centaurus Association 

    Hinkley, Sasha; Kraus, Adam L.; Ireland, Michael J.; Cheetham, Anthony; Carpenter, John M.; Tuthill, Peter; Lacour, Sylvestre; Evans, T.M.; Haubois, Xavier (American Astronomical Society / IoP Publishing, 2015-06-04)
    We report the detection of seven low-mass companions to intermediate-mass stars (SpT B/A/F; M ∼ 1.5–4.5Me) in the Scorpius–Centaurus (Sco–Cen) Association using nonredundant aperture masking interferometry. Ournewly detected ...
  • Dispersion of collective magnonic modes in stacks of nanoscale magnetic elements 

    Dvornik, Mykola; Kruglyak, V.V. (American Physical Society, 2011)
    We report a numerical study of the dispersion of collective magnonic modes in magnonic crystals formed by stacks of magnetostatically coupled magnetic nanoelements. The calculations reveal that the sign of the magnonic ...
  • Dispersion of surface plasmon polaritons on short-pitch metal gratings 

    Hooper, Ian R.; Sambles, J. Roy (American Physical Society, 2002)
    The dispersion of surface plasmon polaritons (SPPs) has been calculated for short-pitch metal gratings for various depths. For gratings with depths greater than their pitch very flat SPP bands are formed in the zero-order ...
  • Distribution and mass of diffuse and dense CO gas in the Milky Way 

    Roman-Duval, J; Heyer, M; Brunt, C; Clark, P; Klessen, R; Shetty, R (American Astronomical Society, 2016-02-17)
    Emission from carbon monoxide (CO) is ubiquitously used as a tracer of dense star-forming molecular clouds. There is, however, growing evidence that a significant fraction of CO emission originates from diffuse molecular ...
  • Divergence of Casimir stress in inhomogeneous media 

    Simpson, William M.R.; Horsley, S.A.R.; Leonhardt, Ulf (American Physical Society, 2013)
    We examine the local behavior of the regularized stress tensor commonly used in calculations of the Casimir force for a dielectric medium inhomogeneous in one direction. It is shown that the usual expression for the stress ...
  • Domain-wall pinning, nonadiabatic spin-transfer torque, and spin-current polarization in permalloy wires doped with vanadium 

    Lepadatu, S.; Claydon, J.S.; Kinane, C.J.; Charlton, T.R.; Langridge, Sean; Potenza, A.; Dhesi, Sarnjeet S.; Keatley, Paul Steven; Hicken, R.J.; Hickey, B.J.; Marrows, C.H. (American Physical Society, 2010)
    Using pulsed-current measurements we investigate the domain-wall depinning via spin-transfer torque from pinning potentials in V-doped Ni80Fe20 wires. The domain-wall depinning boundary, showing the variation of threshold ...
  • Dominance of interface chemistry over the bulk properties in determining the electronic structure of epitaxial metal/perovskite oxide heterojunctions 

    Chambers, SA; Du, Y; Gu, M; Droubay, TC; Hepplestone, SP; Sushko, PV (American Chemical Society, 2015-05-13)
    We show that despite very similar crystallographic properties and work function values in bulk Fe and Cr, epitaxial films of these metals on Nb:SrTiO3(001) exhibit completely different heterojunction electronic properties. ...
  • Double-period zero-order metal gratings as effective selective absorbers 

    Tan, W.-C.; Sambles, J. Roy; Preist, T. W. (American Physical Society, 2000)
    The electromagnetic response of a zero-order metal grating having a primary deep short-period component and a shallow long-period component is modeled. It is found that such a metal grating has an unusual surface-plasmon-polariton ...
  • Drug delivery into microneedle-porated nails from nanoparticle reservoirs. 

    Chiu, Wing Sin; Belsey, Natalie A.; Garrett, Natalie; Moger, Julian; Price, GJ; Begoña Delgado-Charro, M; Guy, Richard H. (Elsevier, 2015-10-15)
    This study demonstrates the potential of polymeric nanoparticles as drug reservoirs for sustained topical drug delivery into microneedle-treated human nail. Laser scanning confocal microscopy was used to image the delivery ...
  • Dynamic configurational anisotropy in nanomagnets 

    Kruglyak, V.V.; Keatley, Paul Steven; Hicken, R.J.; Childress, J.R.; Katine, J.A. (American Physical Society, 2007)
    The angular dependence of ultrafast magnetization dynamics in nanomagnets of square shape was studied by magneto-optical pump-probe measurements. In agreement with micromagnetic simulations, both the number of precessional ...
  • Dynamic control of visible radiation by a liquid crystal filled Fabry-Pérot etalon 

    Jewell, Sharon A.; Cornford, Stephen Leslie; Sambles, J. Roy (American Institute of Physics, 2007)
    A liquid crystal filled Fabry-Pérot etalon has been constructed to control the resonant transmission of electromagnetic radiation over the visible range of the spectrum. This has been achieved through the use of a 1.5 µm ...
  • Dynamical process of switch-off in a supertwisted nematic cell 

    Yang, Fuzi; Dong, Youmei; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2004)
    The switch-off dynamics of a 180° supertwisted nematic (STN) are explored in detail by using a convergent beam system and the fully leaky guided-mode technique. From the dynamical guided-mode data and using the Ericksen–Leslie ...
  • Early Results from VLT-SPHERE: Long-Slit Spectroscopy of 2MASS 0122-2439B, a Young Companion Near the Deuterium Burning Limit 

    Hinkley, Sasha; Bowler, Brendan P.; Vigan, Arthur; Aller, Kimberley M.; Liu, M.C.; Mawet, Dimitri; Matthews, Elisabeth; Wahhaj, Zahed; Kraus, Stefan; Baraffe, I.; Chabrier, G. (American Astronomical Society, 2015-05-19)
    We present 0.95–1.80 µm spectroscopy of the ∼12–27 MJup companion orbiting the faint (R∼13.6), young (∼120Myr) M-dwarf 2MASS J01225093–2439505 (“2M0122–2439B”) at 1.′′5 separation (50 AU). Our coronagraphic long-slit ...
  • The Earth as an extrasolar transiting planet: Earth's atmospheric composition and thickness revealed by Lunar eclipse observations 

    Vidal-Madjar, A.; Arnold, L.; Ehrenreich, D.; Ferlet, R.; Lecavelier des Etangs, A.; Bouchy, F.; Segransan, D.; Boisse, I.; Hebrard, G.; Moutou, C.; Desert, J.-M.; Sing, David K.; Cabanac, R.; Nitschelm, C.; Bonfils, X.; Delfosse, X.; Desort, M.; Diaz, R.F.; Eggenberger, A.; Forveille, T.; Lagrange, A.-M.; Lovis, C.; Pepe, F.; Perrier, C.; Pont, F.; Santos, N.C.; Udry, S. (EDP Sciences for European Southern Observatory (ESO), 2010)
    Context. An important goal within the quest for detecting an Earth-like extrasolar planet, will be to identify atmospheric gaseous bio-signatures. Aims. Observations of the light transmitted through the Earth’s atmosphere, ...
  • The effect of episodic accretion on the phase transition of CO and CO2 in low-mass star formation 

    Vorobyov, Eduard I.; Baraffe, I.; Harries, Tim J.; Chabrier, G. (EDP Sciences for European Southern Observatory (ESO), 2013)
    We study the evaporation and condensation of CO and CO_2 during the embedded stages of low-mass star formation by using numerical simulations. We focus on the effect of luminosity bursts, similar in magnitude to FUors and ...
  • Effect of episodic accretion on the structure and the lithium depletion of low-mass stars and planet-hosting stars 

    Baraffe, I.; Chabrier, G. (EDP Sciences, 2010)
    Following up our recent analysis devoted to the impact of non steady accretion on the location of young low-mass stars or brown dwarfs in the Herzsprung-Russell diagram, we perform a detailed analysis devoted to the effect ...