9,107 research outputs found

    Ferromagnetic resonance imaging of Co films using magnetic resonance force microscopy

    Get PDF
    Lateral one-dimensional imaging of cobalt (Co) films by means of microscopic ferromagnetic resonance (FMR) detected using the magnetic resonance force microscope (MRFM) is demonstrated. A novel approach involving scanning a localized magnetic probe is shown to enable FMR imaging in spite of the broad resonance linewidth. We introduce a spatially selective local field by means of a small, magnetically polarized spherical crystallite of yttrium iron garnet (YIG). Using MRFM-detected FMR signals from a sample consisting of two Co films, we can resolve the ∼20 μm lateral separation between the films. The results can be qualitatively understood by consideration of the calculated spatial profiles of the magnetic field generated by the YIG sphere

    Fracture toughness and crack-resistance curve behavior in metallic glass-matrix composites

    Get PDF
    Nonlinear-elastic fracture mechanics methods are used to assess the fracture toughness of bulk metallic glass (BMG) composites; results are compared with similar measurements for other monolithic and composite BMG alloys. Mechanistically, plastic shielding gives rise to characteristic resistance-curve behavior where the fracture resistance increases with crack extension. Specifically, confinement of damage by second-phase dendrites is shown to result in enhancement of the toughness by nearly an order of magnitude relative to unreinforced glass

    Inhomogeneous Low Frequency Spin Dynamics in La_{1.65}Eu_{0.2}Sr_{0.15}CuO_4

    Full text link
    We report Cu and La nuclear magnetic resonance (NMR) measurements in the title compound that reveal an inhomogeneous glassy behavior of the spin dynamics. A low temperature peak in the La spin lattice relaxation rate and the ``wipeout'' of Cu intensity both arise from these slow electronic spin fluctuations that reveal a distribution of activation energies. Inhomogeneous slowing of spin fluctuations appears to be a general feature of doped lanthanum cuprate.Comment: 4 pages, 2 figures. Very slight modifications to figure

    Gust-Load Alleviation of a Flexible Aircraft using a Disturbance Observer

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143016/1/6.2017-1718.pd

    A Calculation of Baryon Diffusion Constant in Hot and Dense Hadronic Matter Based on an Event Generator URASiMA

    Get PDF
    We evaluate thermodynamical quantities and transport coefficients of a dense and hot hadronic matter based on an event generator URASiMA (Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm). The statistical ensembles in equilibrium with fixed temperature and chemical potential are generated by imposing periodic boundary condition to the simulation of URASiMA, where energy density and baryon number density is conserved. Achievement of the thermal equilibrium and the chemical equilibrium are confirmed by the common value of slope parameter in the energy distributions and the saturation of the numbers of contained particles, respectively. By using the generated ensembles, we investigate the temperature dependence and the chemical potential dependence of the baryon diffusion constant of a dense and hot hadronic matter.Comment: 15 pages, 5 figures, LaTeX2

    From product dispensing to patient care: The role of the pharmacist in providing pharmaceutical care as part of an integrated disease management approach

    Get PDF
    During the past decade, the profession of pharmacy has changed dramatically. The Doctor of Pharmacy degree has replaced the Bachelor of Science degree as the first professional degree offered at most accredited U.S. pharmacy schools. Advanced clinical training is now a mainstay of pharmacy training, and this has enabled pharmacists to contribute to disease management efforts. In addition, technological improvements in prescription processing have afforded pharmacists more time to participate in disease management activities. This paper describes how the role of the pharmacist has changed and reviews the results of programs involving pharmacists as disease management providers in the areas of asthma, hypertension, diabetes, and hyperlipidemia. Pharmacists\u27 contributions in various practice settings are also discussed

    An extreme [OIII] emitter at z=3.2z=3.2: a low metallicity Lyman continuum source

    Get PDF
    [Abridged] We investigate the physical properties of a Lyman continuum emitter candidate at z=3.212z=3.212 with photometric coverage from UU to MIPS 24μ\mum band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with S/N>5S/N>5. Non-zero Lyα\alpha flux at the systemic redshift and high Lyman-α\alpha escape fraction suggest a low HI column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The [OIII]λλ4959,5007+Hβ\lambda\lambda4959,5007+\mathrm{H}\beta equivalent width is one of the largest reported for a galaxy at z>3z>3 (EW([OIII]λλ4959,5007+Hβ)1600A˚\mathrm{EW}([\mathrm{OIII}]\lambda\lambda4959,5007+\mathrm{H}\beta) \simeq 1600\AA, rest-frame) and the NIR spectrum shows that this is mainly due to an extremely strong [OIII] emission. The large observed [OIII]/[OII] ratio (>10>10) and high ionization parameter are consistent with prediction from photoionization models in case of a density-bounded nebula scenario. Furthermore, the EW([OIII]λλ4959,5007+Hβ)\mathrm{EW}([\mathrm{OIII}]\lambda\lambda4959,5007+\mathrm{H}\beta) is comparable to recent measurements reported at z79z\sim7-9, in the reionization epoch. We also investigate the possibility of an AGN contribution to explain the ionizing emission but most of the AGN identification diagnostics suggest that stellar emission dominates instead. This source is currently the first high-zz example of a Lyman continuum emitter exhibiting indirect and direct evidences of a Lyman continuum leakage and having physical properties consistent with theoretical expectation from Lyman continuum emission from a density-bounded nebula.Comment: 14 pages, 11 figures, accepted for publication in A&A. Minor modifications, Figure 2 updated, Figure 9 adde

    Hubble imaging of the ionizing radiation from a star-forming galaxy at z=3.2 with fesc>50%

    Get PDF
    Star-forming galaxies are considered to be the leading candidate sources that dominate the cosmic reionization at z>7, and the search for analogs at moderate redshift showing Lyman continuum (LyC) leakage is currently a active line of research. We have observed a star-forming galaxy at z=3.2 with Hubble/WFC3 in the F336W filter, corresponding to the 730-890A rest-frame, and detect LyC emission. This galaxy is very compact and also has large Oxygen ratio [OIII]5007/[OII]3727 (>=10). No nuclear activity is revealed from optical/near-infrared spectroscopy and deep multi-band photometry (including the 6Ms X-ray, Chandra). The measured escape fraction of ionizing radiation spans the range 50-100\%, depending on the IGM attenuation. The LyC emission is detected at S/N=10 with m(F336W)=27.57+/-0.11 and it is spatially unresolved, with effective radius R_e<200pc. Predictions from photoionization and radiative transfer models are in line with the properties reported here, indicating that stellar winds and supernova explosions in a nucleated star-forming region can blow cavities generating density-bounded conditions compatible with optically thin media. Irrespective to the nature of the ionizing radiation, spectral signatures of these sources over the entire electromagnetic spectrum are of central importance for their identification during the epoch of reionization, when the LyC is unobservable. Intriguingly, the Spitzer/IRAC photometric signature of intense rest-frame optical emissions ([OIII]+Hbeta) observed recently at z~7.5-8.5 is similar to what is observed in this galaxy. Only the James Webb Space Telescope will measure optical line ratios at z>7 allowing a direct comparison with lower redshift LyC emitters, as reported here.Comment: 6 pages, 5 figures, ApJ submitted (comments welcome

    A New Scintillator Tile/Fiber Preshower Detector for the CDF Central Calorimeter

    Full text link
    A detector designed to measure early particle showers has been installed in front of the central CDF calorimeter at the Tevatron. This new preshower detector is based on scintillator tiles coupled to wavelength-shifting fibers read out by multi-anode photomultipliers and has a total of 3,072 readout channels. The replacement of the old gas detector was required due to an expected increase in instantaneous luminosity of the Tevatron collider in the next few years. Calorimeter coverage, jet energy resolution, and electron and photon identification are among the expected improvements. The final detector design, together with the R&D studies that led to the choice of scintillator and fiber, mechanical assembly, and quality control are presented. The detector was installed in the fall 2004 Tevatron shutdown and started collecting colliding beam data by the end of the same year. First measurements indicate a light yield of 12 photoelectrons/MIP, a more than two-fold increase over the design goals.Comment: 5 pages, 10 figures (changes are minor; this is the final version published in IEEE-Trans.Nucl.Sci.
    corecore