5,022 research outputs found
RDLS-SS-DWT v. 0.9
No full textThis fileset contains the implementation of RDLS-DWT and SS-DWT in JPEG 2000 (RDLS-SS-DWT v. 0.9), which was used in a research described in: R. Starosolski, “Application of reversible denoising and lifting steps to DWT in lossless JPEG 2000 for improved bitrates,” Signal Processing: Image Communication, Vol. 39, Part A, pp. 249-63, DOI: 10.1016/j.image.2015.09.013, 2015 and R. Starosolski, “Skipping selected steps of DWT computation in lossless JPEG 2000 for improved bitrates,” submitted. This software is intended for research purposes only; it is provided "as is"; author makes no warranty of any kind, either express or implied, with respect to this software. <br
Charged particle dynamics in multiple colliding electromagnetic waves. Survey of random walk, Levy flights, limit circles, attractors and structurally determinate patterns
No full textThe multiple colliding laser pulse concept formulated by Bulanov et al. (Phys. Rev. Lett., vol. 104, 2010b, 220404) is beneficial for achieving an extremely high amplitude of coherent electromagnetic field. Since the topology of electric and magnetic fields of multiple colliding laser pulses oscillating in time is far from trivial and the radiation friction effects are significant in the high field limit, the dynamics of charged particles interacting with the multiple colliding laser pulses demonstrates remarkable features corresponding to random walk trajectories, limit circles, attractors, regular patterns and Levy flights. Under extremely high intensity conditions the nonlinear dissipation mechanism stabilizes the particle motion resulting in the charged particle trajectory being located within narrow regions and in the occurrence of a new class of regular patterns made by the particle ensembles.Office of Science of the US DOE [DE-AC02-05CH11231]; National Basic Research Program of China [2013CBA01502]; NSFC [11535001]; National Grand Instrument Project [2012YQ030142]SCI(E)ARTICLE8
Ion Acceleration by the Radiation Pressure of a Slow Electromagnetic Wave Interacting with Thin Foil and Extended Plasma Targets and Ion-Ion Beam Instability
No full textWhen ions are accelerated by the radiation pressure of a laser pulse, their velocity cannot exceed the pulse group velocity which can be considerably smaller than the speed of light in vacuum. This is demonstrated in two cases corresponding to a thin foil target irradiated by high intensity laser light and to the hole boring produced in an extended plasma by the laser pulse. It is found that the beams of accelerated ions are unstable against Buneman-like and Weibel-like instabilities which results in the broadening of the ion energy spectrum
Nonlinear generation of ultra-short electromagnetic pulses in plasmas
No full textWhen a low-frequency relativistic soliton interacts with the electron density modulations of a wake plasma wave, part of the soliton electromagnetic energy is reflected in the form of an extremely short and ultraintense electromagnetic pulse. By computing analytically the spectra of the reflected and of the transmitted electromagnetic pulses, we show that the reflected wave has the form of a single cycle attosecond pulse. (c) 2005 Elsevier B.V. All rights reserved
Single-cycle high-intensity electromagnetic pulse generation in the interaction of a plasma wakefield with regular nonlinear structures (vol 73, art no 036408, 2006)
No full textSingle-cycle high-intensity electromagnetic pulse generation in the interaction of a plasma wakefield with regular nonlinear structures
No full textThe interaction of regular nonlinear structures (such as subcycle solitons, electron vortices, and wake Langmuir waves) with a strong wake wave in a collisionless plasma can be exploited in order to produce ultrashort electromagnetic pulses. The electromagnetic field of the nonlinear structure is partially reflected by the electron density modulations of the incident wake wave and a single-cycle high-intensity electromagnetic pulse is formed. Due to the Doppler effect the length of this pulse is much shorter than that of the nonlinear structure. This process is illustrated with two-dimensional particle-in-cell simulations. The considered laser-plasma interaction regimes can be achieved in present day experiments and can be used for plasma diagnostics
SS Northland Echo
No full textPhotograph - A view of the steamboat, SS Northland Echo on the Athabasca River. Athabasca, Albert
SS Athabasca River - 02
No full textPhotograph - A view of the SS Athabasca River paddle steamer on the river, Athabasca, Albert
RIC-HSCT for MF/SS
No full textAdvanced-stage mycosis fungoides and Sezary syndrome (MF/SS) have a poor prognosis. Allogeneic hematopoietic stem cell transplantation (HSCT), particularly using a reduced-intensity conditioning (RIC) regimen, is a promising treatment for advanced-stage MF/SS. We performed RIC-HSCT in nine patients with advanced MF/SS. With a median follow-up period of 954days after HSCT, the estimated 3-year overall survival was 85.7% (95% confidence interval, 33.4-97.9%) with no non-relapse mortality. Five patients relapsed after RIC-HSCT; however, in four patients whose relapse was detected only from the skin, persistent complete response was achieved in one patient, and the disease was manageable in other three patients by the tapering of immunosuppressants and donor lymphocyte infusion, suggesting that graft-versus-lymphoma effect and "down-staging" effect from advanced stage to early stage by HSCT improve the prognosis of advanced-stage MF/SS. These results suggest that RIC-HSCT is an effective treatment for advanced MF/SS
Radiation pressure acceleration: The factors limiting maximum attainable ion energy
No full textRadiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy
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