2,948 research outputs found
EFFECT OF LARGE-SCALE TURBULENT STRUCTURES ON THE LIFT-OFF BEHAVIOR OF TURBULENT-JET DIFFUSION FLAMES
No full textThis paper describes an experimental investigation into the time-dependent lift-off behaviour of flames stabilised in an axisymmetric turbulent jet. Reactive MIE scattering techniques and high-speed CCD photography were employed to investigate the behaviour of lifted flames and the flow field in the near-nozzle region of isothermal jets, attached flames and lifted flames. With the flow-visualisation techniques it was observed that the lowest point of the base of the lifted flame rotates around the periphery of the jet, and this rotary behaviour was confirmed by temperature fluctuations at the base of the lifted flame. From visualisation of various entrainment patterns of the ambient air into the jet fluid, the rotary behaviour is seen to give rise to azimuthal variations in the instant lift-off height. The rotary behaviour of the lifted flame base sets up large-scale helical vortices in the isothermal region of the lifted flame, in the near field of the nozzle. In this study it is also suggested that both the lobe size and the local jet diameter should be considered for determining the large-scale mixing time in connection with the large-scale structural mixing model of the lifted flame. Obviously, the physical mechanism of the lifted flame is not yet sufficiently well understood; the present investigation was therefore performed in order to provide more detailed understanding of the lift-off behaviour in relation to large-scale turbulent structures
A variable step-size diffusion affine projection algorithm
No full textThis paper presents a new variable step-size diffusion affine projection algorithm (VSS-DAPA) to advance the filter performance of the diffusion affine projection algorithm (DAPA). The proposed VSS strategy is developed for the DAPA, which can solve the distributed estimation problem over diffusion networks well. To obtain the optimal step size reasonably, we seek the update recursion of mean-square deviation (MSD) that is suitable for the DAPA. The step size is optimally given through the minimization for the MSD of the DAPA at each iteration. The derived step size through the MSD minimization improves the filter performance with respect to the convergence and the estimation error in steady state. The results based on simulations demonstrate that the proposed VSS-DAPA performs better than the existing algorithms with a system-identification scenario in diffusion network. Copyright (C) 2015 John Wiley & Sons, Ltd.1110sciescopu
Design, Fabrication and Implementation of a Novel Microfluidic Platform for Investigation of Bacterial Cancer Targeting
No full textDIFFRACTION BY AN ARBITRARY-ANGLED DIELECTRIC WEDGE .2. CORRECTION TO PHYSICAL OPTICS SOLUTION
No full textIn Part I of these two companion papers, the physical optics solution for the diffraction by an arbitrary-angled dielectric wedge was derived from the formulation of the dual integral equation. In this paper, the error of the physical optics solution for the E-polarized planewave incidence is corrected by calculating the nonuniform current distributed along the dielectric interfaces. Two kinds of series expansions to the nonuniform current are employed here. One is an asymptotic expansion as the multipole line source located at the edge of the dielectric wedge since the correction field seems to be a cylindrical wave emanating from the edge in far-field region. The other is arbitrary electric and magnetic surface currents expanded by infinite series of the Bessel functions, i.e., the Neumann's expansion, of which fractional order is chosen to satisfy the edge condition near the edge of the dielectric wedge in the static limit. Both of the two different expansion coefficients for wedge angle 45-degrees, relative dielectric constant 2, 10, and 100, and the E-polarized incident angle 150-degrees are evaluated by solving the dual series equation numerically after finite truncation. The far-field patterns are calculated and the validity of the two different expansions is also discussed
Hematological effects of Blastocystis hominis infection in male foreign workers in Taiwan.
No full textMagnetization switching of CoPd alloy film on piezoelectric substrate via inverse piezoelectric effect
No full textThe magnetization switching Of Co0.25Pd0.75 alloy film on Pb(Zr-0.52 Ti-0.48)O-3 substrate was studied, by measuring the polar Kerr rotation hysteresis loops and their electric field dependencies. It was found that the direction of spontaneous magnetization in CoPd alloy film was easily controllable via the inverse piezoelectric effect of the lead zirconate titanate layer, judging from the change of the Kerr rotation hysteresis loops with respect to an applied voltage. Since the magnetization direction maintains its initial state even when the applied voltage is turned off, this system is applicable to a future nonvolatile memory device
Spin engineering of CoPd alloy films via the inverse piezoelectric effect
No full textThe spin engineering of CoxPd1-x alloy films on Pb(Zr0.52Ti0.48)O-3 substrates was studied by measuring the polar Kerr rotation hysteresis loops and their electric field dependencies. The electric field dependence of polar Kerr rotation strongly depends on the composition of the CoPd alloys. This is especially so in the case of Co0.25Pd0.75 alloy film where the hysteresis loop of magnetic remanence with respect to voltage applied is nearly squared, i.e., the direction of magnetization maintains its initial state even when the voltage applied is turned off. This spin engineering in a ferromagnetic/piezoelectric hybrid system is possible mainly due to a combination of the magnetostrictive effect and the inverse piezoelectric effect. The results are applicable to future nonvolatile memory devices. (C) 2003 American Institute of Physics.This work was supported by the Korean Ministry of Science
and Technology through the Creative Research Initiative
Project
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