Diffusion in supersonic, turbulent, compressible flows

We investigate diffusion in supersonic, turbulent, compressible flows. Supersonic turbulence can be characterized as network of interacting shocks. We consider flows with different rms Mach numbers and where energy necessary to maintain dynamical equilibrium is inserted at different spatial scales. We find that turbulent transport exhibits super-diffusive behavior due to induced bulk motions. In a comoving reference frame, however, diffusion behaves normal and can be described by mixing length theory extended into the supersonic regime.Comment: 11 pages, incl. 5 figures, accepted for publication in Physical Review E (a high-resolution version is available at http://www.aip.de./~ralf/Publications/p21.abstract.html

Inverse cascade in decaying 3D magnetohydrodynamic turbulence

We perform direct numerical simulations of three-dimensional freely decaying magnetohydrodynamic (MHD) turbulence. For helical magnetic fields an inverse cascade effect is observed in which power is transfered from smaller scales to larger scales. The magnetic field reaches a scaling regime with self-similar evolution, and power law behavior at high wavenumbers. We also find power law decay in the magnetic and kinematic energies, and power law growth in the characteristic length scale of the magnetic field.Comment: 6 pages, 5 figures, minor changes to match published versio

The Structure of Jupiter, Saturn, and Exoplanets: Key Questions for High-Pressure Experiments

We give an overview of our current understanding of the structure of gas giant planets, from Jupiter and Saturn to extrasolar giant planets. We focus on addressing what high-pressure laboratory experiments on hydrogen and helium can help to elucidate about the structure of these planets.Comment: Invited contribution to proceedings of High Energy Density Laboratory Astrophysics, 6. Accepted to Astrophysics & Space Science. 12 page

Stress testing and non-invasive coronary angiography in patients with suspected coronary artery disease: time for a new paradigm

Diagnosis and management of coronary artery disease represents major challenges to our health care system, affecting millions of patients each year. Until recently, the diagnosis of coronary artery disease was possible only through cardiac catheterization and invasive coronary angiography. To avoid the risks of an invasive procedure, stress testing is often employed for an initial assessment of patients with suspected coronary artery disease, serving as a gatekeeper for cardiac catheterization. With the emergence of non-invasive coronary angiography, the question arises if such a strategy is still sensible, particularly, in view of only a modest agreement between stress testing results and the presence of coronary artery disease established by cardiac catheterization. Much data in support of the diagnostic accuracy and prognostic value of non-invasive coronary angiography by computed tomography have emerged within the last few years. These data challenge the role of stress testing as the initial imaging modality in patients with suspected coronary artery disease. This article reviews the clinical utility, limitations, as well as the hazards of stress testing compared with non-invasive coronary artery imaging by computed tomography. Finally, the implications of this review are discussed in relation to clinical practice

Characteristics of SBR, Neoprene and EPDM compounds in a single-pass pendulum scratch

In this study, the effect of carbon black on the scratch and deformation characteristics of styrene-butadiene rubber (SBR), polychloroprene (Neoprene) and ethylene propylene diene monomer rubber (EPDM) were evaluated using single-pass pendulum scratch technique. The introduction of carbon black as a reinforcing agent tends to impart better scratch resistance characteristics to all rubber compounds except EPDM. The scratch mode was observed to change from brittle to ductile. The energy lost, average frictional force, scratch resistance and scratch damage response were found to be greatly influenced by scratch load and release angle of the pendulum. (C) 2012 Elsevier Ltd. All rights reserved

Pharmacokinetics of once daily intraperitoneal cefazolin in continuous ambulatory peritoneal dialysis patients

Journal of the American Society of Nephrology1161117-1121JASN

The contact resistance at the interface between a disc electrode and an infinite slab: Mixed-boundary-value solutions

Solid State Electronics295535-543SSEL

Mnemonic effect of iconic gesture and beat gesture in adults and children: Is meaning in gesture important for memory recall?

10.1080/01690965.2011.573220Language and Cognitive Processes275665-681LCPR