Demonstration of dispersive rarefaction shocks in hollow elliptical cylinder chains

We report an experimental and numerical demonstration of dispersive rarefaction shocks (DRS) in a 3D-printed soft chain of hollow elliptical cylinders. We find that, in contrast to conventional nonlinear waves, these DRS have their lower amplitude components travel faster, while the higher amplitude ones propagate slower. This results in the backward-tilted shape of the front of the wave (the rarefaction segment) and the breakage of wave tails into a modulated waveform (the dispersive shock segment). Examining the DRS under various impact conditions, we find the counter-intuitive feature that the higher striker velocity causes the slower propagation of the DRS. These unique features can be useful for mitigating impact controllably and efficiently without relying on material damping or plasticity effects

In situ transmission electron microscopy studies of shear bands in a bulk metallic glass based composite

In situ straining transmission electron microscopy (TEM) experiments were performed to study the propagation of the shear bands in the Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 bulk metallic glass based composite. Contrast in TEM images produced by shear bands in metallic glass and quantitative parameters of the shear bands were analyzed. It was determined that, at a large amount of shear in the glass, the localization of deformation occurs in the crystalline phase, where formation of dislocations within the narrow bands are observed

Idiopathic CD4+ T-lymphocytopenia with cryptococcal meningitis: first case report from Cambodia.

We report on a patient with cryptococcal meningitis with CD4+ T-lymphocytopenia and no evidence of HIV infection

Fluid Coexistence close to Criticality: Scaling Algorithms for Precise Simulation

A novel algorithm is presented that yields precise estimates of coexisting liquid and gas densities, $\rho^{\pm}(T)$, from grand canonical Monte Carlo simulations of model fluids near criticality. The algorithm utilizes data for the isothermal minima of the moment ratio $Q_{L}(T;_{L})$ $\equiv< m^{2}>_{L}^{2}/_{L}$ in $L$$\times$$...$$\times$$L$ boxes, where $m=\rho-_{L}$. When $L$$\to$$\infty$ the minima, $Q_{\scriptsize m}^{\pm}(T;L)$, tend to zero while their locations, $\rho_{\scriptsize m}^{\pm}(T;L)$, approach $\rho^{+}(T)$ and $\rho^{-}(T)$. Finite-size scaling relates the ratio {\boldmath $\mathcal Y$}$=$$(\rho_{\scriptsize m}^{+}-\rho_{\scriptsize m}^{-})/\Delta\rho_{\infty}(T)$ {\em universally} to ${1/2}(Q_{\scriptsize m}^{+}+Q_{\scriptsize m}^{-})$, where $\Delta\rho_{\infty}$$=$$\rho^{+}(T)-\rho^{-}(T)$ is the desired width of the coexistence curve. Utilizing the exact limiting $(L$$\to$$\infty)$ form, the corresponding scaling function can be generated in recursive steps by fitting overlapping data for three or more box sizes, $L_{1}$, $L_{2}$, $...$, $L_{n}$. Starting at a $T_{0}$ sufficiently far below $T_{\scriptsize c}$ and suitably choosing intervals $\Delta T_{j}$$=$$T_{j+1}-T_{j}$$>$0 yields $\Delta\rho_{\infty}(T_{j})$ and precisely locates $T_{\scriptsize c}$