Acoustic Spectroscopy of Superfluid 3He in Aerogel

We have designed an experiment to study the role of global anisotropic quasiparticle scattering on the dirty aerogel superfluid 3He system. We observe significant regions of two stable phases at temperatures below the superfluid transition at a pressure of 25 bar for a 98% aerogel.Comment: 2 pages, 2 figures, accepted for publication in proceedings of Low Temperature Conference 2

Charge metastability and hysteresis in the quantum Hall regime

We report simultaneous quasi-dc magnetotransport and high frequency surface acoustic wave measurements on bilayer two-dimensional electron systems in GaAs. Near strong integer quantized Hall states a strong magnetic field sweep hysteresis in the velocity of the acoustic waves is observed at low temperatures. This hysteresis indicates the presence of a metastable state with anomalously high conductivity in the interior of the sample. This non-equilibrium state is not revealed by conventional low frequency transport measurements which are dominated by dissipationless transport at the edge of the 2D system. We find that a field-cooling technique allows the equilibrium charge configuration within the interior of the sample to be established. A simple model for this behavior is discussed.Comment: 8 pages, 4 postscript figure

Specific Heat of Disordered 3^{3}He

Porous aerogel is a source of elastic scattering in superfluid 3He and modifies the properties of the superfluid, suppressing the transition temperature and order parameter. The specific heat jumps for the B-phase of superfluid 3He in aerogel have been measured as a function of pressure and interpreted using the homogeneous and inhomogeneous isotropic scattering models. The specific heat jumps for other p-wave states are estimated for comparison.Comment: Manuscript prepared for LT 2

Sudden death due to hemoperitoneum following rupture of cirrhosis-related mesenteric varices

AbstractVarices are caused by increased hemodynamic stress on venous channels due to portal hypertension complicating cirrhosis. Although esophageal varices are the most common site of variceal rupture in cirrhosis, mesenteric variceal rupture causing hemoperitoneum is a rare but fatal complication. There are three similar previously reported cases in the literature. We report a fatal case of hemoperitoneum in a woman caused by spontaneous rupture of mesenteric varices as a result of cirrhosis due to chronic alcoholism. The original site of hemorrhage may remain obscure if the lesion is subtle and overlooked. Therefore a diligent search for mesenteric varices is indicated in all cases with unexplained hemoperitoneum

Anisotropic Aerogels for Studying Superfluid 3^3He

It may be possible to stabilize new superfluid phases of $^{3}$He with anisotropic silica aerogels. We discuss two methods that introduce anisotropy in the aerogel on length scales relevant to superfluid $^{3}$He. First, anisotropy can be induced with uniaxial strain. A second method generates anisotropy during the growth and drying stages. We have grown cylindrical $\sim$98% aerogels with anisotropy indicated by preferential radial shrinkage after supercritical drying and find that this shrinkage correlates with small angle x-ray scattering (SAXS). The growth-induced anisotropy was found to be $\sim90^\circ$ out of phase relative to that induced by strain. This has implications for the possible stabilization of superfluid phases with specific symmetry.Comment: 6 pages, 4 figures, submitted to Quantum Fluids and Solids (QFS) conference 200

Contrasting Information Systems and Financial Executive Perspective on Implementing Regulatory Controls

New corporate compliance regulations such as the Sarbanes Oxley (SOX) Act of 2002 contain requirements for the chief executive and financial officers to certify the effectiveness of internal controls and processes leading to financial reporting. An inevitable result of implementing compliance with these regulations is an increased focus on improving systems and greater interdependence between the financial and IS functions. In this paper, we analyse the data collected on implementation of regulatory compliance and present some new empirical insights on the regulatory control implementation process and consequential changes in the institutional properties of IS and the accounting functions within the organization