29,336 research outputs found
Design and Implementation of an RNS-based 2D DWT Processor
No abstract availabl
Relaxation of a Single Knotted Ring Polymer
The relaxation of a single knotted ring polymer is studied by Brownian
dynamics simulations. The relaxation rate lambda_q for the wave number q is
estimated by the least square fit of the equilibrium time-displaced correlation
function to a double exponential decay at long times. The relaxation rate
distribution of a single ring polymer with the trefoil knot appears to behave
as lambda_q=A(1/N^)x for q=1 and lambda_q=A'(q/N)^x' for q=2 and 3, where
x=2.61, x'=2.02 and A>A'. The wave number q of the slowest relaxation rate for
each N is given by q=2 for small values of N, while it is given by q=1 for
large values of N. This crossover corresponds to the change of the structure of
the ring polymer caused by the localization of the knotted part to a part of
the ring polymer.Comment: 13 pages, 5 figures, uses jpsj2.cl
Tidal Interaction between a Fluid Star and a Kerr Black Hole in Circular Orbit
We present a semi-analytic study of the equilibrium models of close binary
systems containing a fluid star (mass and radius ) and a Kerr black
hole (mass ) in circular orbit. We consider the limit where
spacetime is described by the Kerr metric. The tidally deformed star is
approximated by an ellipsoid, and satisfies the polytropic equation of state.
The models also include fluid motion in the stellar interior, allowing binary
models with nonsynchronized stellar spin (as expected for coalescing neutron
star-black hole binaries) to be constructed. Tidal disruption occurs at orbital
radius , but the dimensionless ratio depends on the spin parameter of
the black hole as well as on the equation of state and the internal rotation of
the star. We find that the general relativistic tidal field disrupts the star
at a larger than the Newtonian tide; the difference is
particularly prominent if the disruption occurs in the vicinity of the black
hole's horizon. In general, is smaller for a (prograde
rotating) Kerr black hole than for a Schwarzschild black hole. We apply our
results to coalescing black hole-neutron star and black hole-white dwarf
binaries. The tidal disruption limit is important for characterizing the
expected gravitational wave signals and is relevant for determining the
energetics of gamma ray bursts which may result from such disruption.Comment: 29 pages including 8 figures. Minor changes and update. To appear in
ApJ, March 20, 2000 (Vol.532, #1
Microwave imaging of mesoscopic percolating network in a manganite thin film
Many unusual behaviors in complex oxides are deeply associated with the
spontaneous emergence of microscopic phase separation. Depending on the
underlying mechanism, the competing phases can form ordered or random patterns
at vastly different length scales. Using a microwave impedance microscope, we
observed an orientation-ordered percolating network in strained Nd0.5Sr0.5MnO3
thin films with a large period of 100 nm. The filamentary metallic domains
align preferentially along certain crystal axes of the substrate, suggesting
the anisotropic elastic strain as the key interaction in this system. The local
impedance maps provide microscopic electrical information of the hysteretic
behavior in strained thin film manganites, suggesting close connection between
the glassy order and the colossal magnetoresistance effects at low
temperatures.Comment: 4 pages,4 figure
Absence of a Role for Phosphorylation in the Tau Pathology of Alzheimer's Disease
Acknowledgments: Depolymerised bovine tubulin was kindly donated by J. Kilmartin (MRC Laboratory of Molecular Biology, Cambridge). This work was supported by the Medical Research Council (UK), a Wellcome Trust Studentship to RL, the Leopold Muller Estate, and the Newton Trust (Trinity College, Cambridge). We gratefully acknowledge Academic Books for permission to use Table 2 and Figures 2–4 which correspond to Table 1 and Figures 20–22 from Wischik C.M., Lai, R.Y.K. and Harrington, C.R. Modelling prion-like processing of tau protein in Alzheimer’s disease for pharmaceutical development, in Brain Microtubule Associated Proteins: Modifications in Disease, Avila, J.; Brandt, R.; Kosik, K.S., Eds. Harwood Academic Publishers: Amsterdam, The Netherlands, 1997. Erratum published on 12 August 2016, see Biomolecules 2016, 6(3), 35. http://www.mdpi.com/2218-273X/6/3/35Peer reviewedPublisher PD
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