Weak shock compaction on granular salt.

This study conducted integrated experiments and computational modeling to investigate the speeds of a developing shock within granular salt and analyzed the effect of various impact velocities up to 245 m/s. Experiments were conducted on table salt utilizing a novel setup with a considerable bore length for the sample, enabling visualization of a moving shock wave. Experimental analysis using particle image velocimetry enabled the characterization of shock velocity and particle velocity histories.

Analytic dynamics of the Morse oscillator derived by semiclassical closures.

The quantized Hamilton dynamics methodology [O. V. Prezhdo and Y.

Canonical averaging in the second order quantized Hamilton dynamics by extension of the coherent state thermodynamics of the harmonic oscillator.

A conceptually simple approximation to quantum mechanics, quantized Hamilton dynamics (QHD) includes zero-point energy, tunneling, dephasing, and other important quantum effects in a classical-like description. The hierarchy of coupled differential equations describing the time evolution of observables in QHD can be mapped in the second order onto a classical system with double the dimensionality of the original system. While QHD excels at dynamics with a single initial condition, the correct method for generating thermal initial conditions in QHD remains an open question.

Second-order quantized Hamilton dynamics coupled to classical heat bath.

Starting with a quantum Langevin equation describing in the Heisenberg representation a quantum system coupled to a quantum bath, the Markov approximation and, further, the closure approximation are applied to derive a semiclassical Langevin equation for the second-order quantized Hamilton dynamics (QHD) coupled to a classical bath. The expectation values of the system operators are decomposed into products of the first and second moments of the position and momentum operators that incorporate zero-point energy and moderate tunneling effects. The random force and friction as well as the system-bath coupling are decomposed to the lowest classical level.

A canonical averaging in the second-order quantized Hamilton dynamics.

Quantized Hamilton dynamics (QHD) is a simple and elegant extension of classical Hamilton dynamics that accurately includes zero-point energy, tunneling, dephasing, and other quantum effects. Formulated as a hierarchy of approximations to exact quantum dynamics in the Heisenberg formulation, QHD has been used to study evolution of observables subject to a single initial condition. In present, we develop a practical solution for generating canonical ensembles in the second-order QHD for position and momentum operators, which can be mapped onto classical phase space in doubled dimensionality and which in certain limits is equivalent to thawed Gaussian.

Percutaneous vertebroplasty in the treatment of vertebral body compression fracture secondary to osteogenesis imperfecta.

Percutaneous vertebroplasty, a minimally invasive interventional radiological procedure, has recently been used effectively for the treatment of symptomatic vertebral body compression fractures. Primary indications for vertebroplasty include osteoporotic compression fracture, osteolytic vertebral metastasis and myeloma, and vertebral hemangioma. We present a case and extend the indication of percutaneous vertebroplasty in a patient with a vertebral body compression fracture secondary to osteogenesis imperfecta.

Predictive value of intraosseous venography before percutaneous vertebroplasty.

Purpose: Percutaneous vertebroplasty is a novel approach for treating patients with painful vertebral body compression fractures. The use of intraosseous venography before the percutaneous injection of polymethylmethacrylate (PMMA) is not universally accepted. The purpose of this study was to determine if intraosseous venography predicts PMMA flow characteristics when injected into a vertebral body.