Numerical Method for Shock Front Hugoniot States

We describe a Continuous Hugoniot Method for the efficient simulation of shock wave fronts. This approach achieves significantly improved efficiency when the generation of a tightly spaced collection of individual steady-state shock front states is desired, and allows for the study of shocks as a function of a continuous shock strength parameter, $v_p$. This is, to our knowledge, the first attempt to map the Hugoniot continuously. We apply the method to shock waves in Lennard-Jonesium along the $$ direction. We obtain very good agreement with prior simulations, as well as our own benchmark comparison runs.Comment: 4 pages, 3 figures, from Shock Compression of Condensed Matter 200

Cracks in rubber under tension exceed the shear wave speed

The shear wave speed is an upper limit for the speed of cracks loaded in tension in linear elastic solids. We have discovered that in a non-linear material, cracks in tension (Mode I) exceed this sound speed, and travel in an intersonic range between shear and longitudinal wave speeds. The experiments are conducted in highly stretched sheets of rubber; intersonic cracks can be produced simply by popping a balloon.Comment: 4 pages, 5 eps figure

Influence of Fields on Grain Boundary Mobility in Alumina

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Berry phase effect in anomalous thermoelectric transport

We develop a theory of Berry phase effect in anomalous transport in ferromagnets driven by statistical forces such as the gradient of temperature or chemical potential. Here a charge Hall current arises from the Berry phase correction to the orbital magnetization rather than from the anomalous velocity which does not exist in the absence of a mechanical force. A finite-temperature formula for the orbital magnetization is derived, which enables us to provide an explicit expression for the off-diagonal thermoelectric conductivity, to establish the Mott relation between the anomalous Nernst and Hall effects, and to reaffirm the Onsager relations between reciprocal thermoelectric conductivities. A first-principles evaluation of our expression is carried out for the material CuCr$_2$Se$_{4-x}$Br$_x$, obtaining quantitative agreement with a recent experiment.Comment: Published version in PR

Theo Gavrielides, Waves of healing: using restorative justice for street group violence

Abstract included in tex

Transillumination imaging through scattering media by use of photorefractive polymers

We demonstrate the use of a near-infrared-sensitive photorefractive polymer with high efficiency for imaging through scattering media, using an all-optical holographic time gate. Imaging through nine scattering mean free paths is performed at 800 nm with a mode-locked continuous-wave Ti:sapphire laser

Berry Curvature on the Fermi Surface: Anomalous Hall Effect as a Topological Fermi-Liquid Property

The intrinsic anomalous Hall effect in metallic ferromagnets is shown to be controlled by Berry phases accumulated by adiabatic motion of quasiparticles on the Fermi surface, and is purely a Fermi-liquid property, not a ``bulk'' Fermi sea property like Landau diamagnetism, as has been previously supposed. Berry phases are a new topological ingredient that must be added to Landau Fermi-liquid theory in the presence of broken inversion or time-reversal symmetry.Comment: 4 pages, 0 figures; to appear in Physical Review Letters; cleaner form of main formula+note added confirming continued validity of result in interacting Fermi liquids: + improved summary paragraph stating result; final published version (minor changes

Dynamical stability of the crack front line

Dynamical stability of the crack front line that propagates between two plates is studied numerically using the simple two-dimensional mass-spring model. It is demonstrated that the straight front line is unstable for low speed while it becomes stable for high speed. For the uniform model, the roughness exponent in the slower speed region is fairly constant around 0.4 and there seems to be a rough-smooth transition at a certain speed. For the inhomogeneous case with quenched randomness, the transition is gradual.Comment: 14 pages, 7 figure

Nudge the judge? Theorizing the interaction between heuristics, sentencing guidelines and sentence clustering

Although it has long been acknowledged that heuristics influence judicial decision making, researchers have yet to explore how sentencing guidelines might interact with heuristics to shape sentencing decisions. This article contributes to addressing this gap in the literature in three ways: first, by considering how heuristics might help produce the phenomenon of sentence clustering, in which a significant proportion of sentences are concentrated around a small number of outcomes; second, by reflecting on the role of sentencing guidelines as a feature of the environment within which sentencing decisions are made; and third, by analysing the guidelines from Minnesota and from England and Wales, theorizing how their content might interact with heuristics to make clustering more or less likely. Ultimately, we argue that sentencing guidelines likely affect the role played by heuristics in shaping sentencing decisions and, consequently, that their design should be informed by research evidence from the decision sciences