27,898 research outputs found

    Improved relay chatter detector

    Get PDF
    Detector provides go/no-go sensing of momentary relay or contact opening during vibration testing. Device compares duration of unwanted openings to calibrated standard and lights indicator if standard is exceeded. Stability and reliability are higher than in any other comparable device

    New Models for X-Ray Synchrotron Radiation from the Remnant of Supernova 1006 AD

    Get PDF
    Galactic cosmic rays up to energies of around 10^15 eV are assumed to originate in supernova remnants (SNRs). The shock wave of a young SNR like SN 1006 AD can accelerate electrons to energies greater than 1 TeV, where they can produce synchrotron radiation in the X-ray band. A new model (SRESC) designed to model synchrotron X-rays from Type Ia supernovae can constrain values for the magnetic-field strength and electron scattering properties, with implications for the acceleration of the unseen ions which dominate the cosmic-ray energetics. New observations by ASCA, ROSAT, and RXTE have provided enormously improved data, which now extend to higher X-ray energies. These data allow much firmer constraints. We will describe model fits to these new data on SN 1006 AD, emphasizing the physical constraints that can be placed on SNRs and on the cosmic-ray acceleration process.Comment: 10 pages, 2 figures. to appear in "Cosmic Explosions", proceeding of the 10th Annual October Astrophysics Conference (ed. S.S. Holt and W. W. Zhang) LaTex aipproc.st

    Hydrogen-fueled engine

    Get PDF
    A hydrogen-oxygen fueled internal combustion engine is described, which utilizes an inert gas, such as argon, as a working fluid to increase the efficiency of the engine, eliminate pollution, and facilitate operation of a closed cycle energy system. In a system where sunlight or other intermittent energy source is available to separate hydrogen and oxygen from water, the oxygen and inert gas are taken into a diesel engine into which hydrogen is injected and ignited. The exhaust is cooled so that it contains only water and the inert gas. The inert gas in the exhaust is returned to the engine for use with fresh oxygen, while the water in the exhaust is returned to the intermittent energy source for reconversion to hydrogen and oxygen

    Implicit theories of firesetters

    Get PDF
    Firesetting has significant social and financial consequences. Firesetters are deemed a dangerous group with a poor prognosis. The existing literature has focused on describing the characteristics of firesetters and developing typologies. The psychological understanding of firesetting is limited. Implicit theories are underlying causal theories. Positioned within a social cognitive framework they are thought to be the intervening process between observable stimuli and responses which enable individuals to make sense of their social world and make predictions within it. The identification of implicit theories has contributed to the understanding of the way information processing is carried out by other offender groups. This study aimed to explore the implicit theories held by male firesetters in secure forensic psychiatric services. Using grounded theory methodology, interviews were conducted with nine men with a history of firesetting. Six implicit theories were generated: malevolent world, uncontrollable world, violence is normal, accountability, fire is controllable and fire is a powerful tool. These implicit theories have the potential to be utilised as treatment targets by challenging and restructuring them. Future research should focus on exploring the specific implicit theories at different points in the offense process, those held by subtypes of firesetters, and those held by female firesetters

    Angle-resolved photoemission spectroscopy of band tails in lightly doped cuprates

    Get PDF
    We amend ab initio strongly-correlated band structures by taking into account the band-tailing phenomenon in doped charge-transfer Mott-Hubbard insulators. We show that the photoemission from band tails accounts for sharp "quasi-particle" peaks, rapid loss of their intensities in some directions of the Brillouin zone ("Fermi-arcs") and high-energy "waterfall" anomalies as a consequence of matrix-element effects of disorder-localised states in the charge-transfer gap of doped cuprates.Comment: 4 pages, 4 figure

    Estimating monthly-averaged air-sea transfers of heat and momentum using the bulk aerodynamic method

    Get PDF
    Air-sea transfers of sensible heat, latent heat, and momentum are computed from twenty-five years of middle-latitude and subtropical ocean weather ship data in the North Atlantic and North Pacific using the bulk aerodynamic method. The results show that monthly-averaged wind speeds, temperatures, and humidities can be used to estimate the monthly-averaged sensible and latent heat fluxes computed from the bulk aerodynamic equations to within a relative error of approximately 10%. The estimate of monthly-averaged wind stress under the assumption of neutral stability are shown to be within approximately 5% of the monthly-averaged non-neutral values

    Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?

    Full text link
    We show from modeling the Fe Kalpha line in the ASCA spectra of four X-ray bright narrow emission line galaxies (Seyfert types 1.9 and 2) that two equally viable physical models can describe the observed line profile. The first is discussed by Turner et al. (1998) and consists of emission from a nearly pole-on accretion disk. The second, which is statistically preferred, is a superposition of emission from an accretion disk viewed at an intermediate inclination of about 48 degrees and a distinct, unresolved feature that presumably originates some distance from the galaxy nucleus. The intermediate inclination is entirely consistent with unified schemes and our findings challenge recent assertions that Seyfert 2 galaxies are preferentially viewed with their inner regions face-on. We derive mean equivalent widths for the narrow and disk lines of =60 eV and = 213 eV, respectively. The X-ray data are well described by a geometry in which our view of the active nucleus intersects and is blocked by the outer edges of the obscuring torus, and therefore do not require severe misalignments between the accretion disk and the torus.Comment: 19 pages, 3 postscript figures. Accepted for publication in ApJ
    corecore