3,657 research outputs found
Off-fault tensile cracks: A link between geological fault observations, lab experiments, and dynamic rupture models
We examine the local nature of the dynamic stress field in the vicinity of the tip of a semi-infinite sub-Rayleigh (slower than the Rayleigh wave speed, c_R) mode II crack with a velocity-weakening cohesive zone. We constrain the model using results from dynamic photoelastic experiments, in which shear ruptures were nucleated spontaneously in Homalite-100 plates along a bonded, precut, and inclined interface subject to a far-field uniaxial prestress. During the experiments, tensile cracks grew periodically along one side of the shear rupture interface at a roughly constant angle relative to the shear rupture interface. The occurrence and inclination of the tensile cracks are explained by our analytical model. With slight modifications, the model can be scaled to natural faults, providing diagnostic criteria for interpreting velocity, directivity, and static prestress state associated with past earthquakes on exhumed faults. Indirectly, this method also allows one to constrain the velocity-weakening nature of natural ruptures, providing an important link between field geology, laboratory experiments, and seismology
Interaction Quench in Nonequilibrium Luttinger Liquids
We study the relaxation dynamics of a nonequilibrium Luttinger liquid after a
sudden interaction switch-on ("quench"), focussing on a double-step initial
momentum distribution function. In the framework of the non-equilibrium
bosonization, the results are obtained in terms of singular Fredholm
determinants that are evaluated numerically and whose asymptotics are found
analytically. While the quasi-particle weights decay exponentially with time
after the quench, this is not a relaxation into a thermal state, in view of the
integrability of the model. The steady-state distribution emerging at infinite
times retains two edges which support Luttinger-liquid-like power-law
singularities smeared by dephasing. The obtained critical exponents and the
dephasing length are found to depend on the initial nonequilibrium state.Comment: 11 pages, 5 figure
Simple Combined Model for Nonlinear Excitations in DNA
We propose a new simple model for DNA denaturation bases on the pendulum
model of Englander\cite{A1} and the microscopic model of Peyrard {\it et
al.},\cite{A3} so called "combined model". The main parameters of our model
are: the coupling constant along each strand, the mean stretching
of the hydrogen bonds, the ratio of the damping constant and driven force
. We show that both the length of unpaired bases and the velocity
of kinks depend on not only the coupling constant but also the
temperature . Our results are in good agreement with previous works.Comment: 6 pages, 10 figures, submitted to Phys. Rev.
Interplay between oxidative stress and inflammation in cardiometabolic syndrome
EditorialAbstract not availableAaron L. Sverdlov, Gemma A. Figtree, John D. Horowitz and Doan T. M. Ng
Problems with Re-Os isochron determinations
We have developed closed-system techniques for the equilibration of Os isotopes and for the calibration of Re and Os tracers using high-purity metals [1]. The results show reproducibility of ±0.5% for calibrations for Os using different chunks of the same high-purity Os metal produced by vacuum arc melting
A deep level set method for image segmentation
This paper proposes a novel image segmentation approachthat integrates fully
convolutional networks (FCNs) with a level setmodel. Compared with a FCN, the
integrated method can incorporatesmoothing and prior information to achieve an
accurate segmentation.Furthermore, different than using the level set model as
a post-processingtool, we integrate it into the training phase to fine-tune the
FCN. Thisallows the use of unlabeled data during training in a
semi-supervisedsetting. Using two types of medical imaging data (liver CT and
left ven-tricle MRI data), we show that the integrated method achieves
goodperformance even when little training data is available, outperformingthe
FCN or the level set model alone
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