Electric discharge for treatment of trace contaminants

A radio frequency glow discharge reactor is described for removing trace oxidizable contaminants from an oxygen bearing atmosphere. The reaction chamber is defined by an inner metal electrode facing a dielectric backed by an outer conductive electrode. In one embodiment, a conductive liquid forms the conductor of an outer electrode and cools the dielectric. A resonator coupled to a variable radio frequency source generates the high voltages for creating a glow discharge in the chamber at a predetermined pressure whereby the trace contaminants are oxidized into a few simple non-toxic products that may be easily recovered. The corresponding process for removal of trace contaminants from an oxygen-bearing atmosphere with high efficiency independent of the concentration level is also disclosed

Drag measurements of an axisymmetric nacelle mounted on a flat plate at supersonic speeds

An experimental investigation was conducted to determine the effect of diverter wedge half-angle and nacelle lip height on the drag characteristics of an assembly consisting of a nacelle fore cowl from a typical high-speed civil transport (HSCT) and a diverter mounted on a flat plate. Data were obtained for diverter wedge half-angles of 4.0 deg, 6.0 deg, and 8.0 deg and ratios of the nacelle lip height above a flat plate to the boundary-layer thickness (h(sub n)/delta) of approximately 0.87 to 2.45. Limited drag data were also obtained on a complete nacelle/diverter configuration that included fore and aft cowls. Although the nacelle/diverter drag data were not corrected for base pressures or internal flow drag, the data are useful for comparing the relative drag of the configuration tested. The tests were conducted in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.50, 1.80, 2.10, and 2.40 and Reynolds numbers ranging from 2.00 x 10(exp 6) to 5.00 x 10(exp 6) per foot. The results of this investigation showed that the nacelle/diverter drag essentially increased linearly with increasing h(sub n)/delta except near 1.0 where the data showed a nonlinear behavior. This nonlinear behavior was probably caused by the interaction of the shock waves from the nacelle/diverter configuration with the flat-plate boundary layer. At the lowest h(sub n)/delta tested, the diverter wedge half-angle had virtually no effect on the nacelle/diverter drag. However, as h(sub n)/delta increased, the nacelle/diverter drag increased as diverter wedge half-angle increased

Rifaximin has the potential to prevent complications of cirrhosis

Background: Cirrhosis-related complications are associated with poor prognosis. With our analyses, we examined the potential benefit of rifaximin in reducing the risk of developing cirrhosis-related complications. Methods: Adults with cirrhosis and hepatic encephalopathy (HE) in remission were randomly assigned to receive rifaximin 550 mg twice daily or placebo for 6 months with concomitant lactulose permitted. Post hoc analyses examined time to cirrhosis-related complications (HE, spontaneous bacterial peritonitis (SBP), variceal bleeding, acute kidney injury/hepatorenal syndrome). Subgroup analyses evaluated efficacy for select baseline disease characteristics. Results: Of patients receiving rifaximin (n = 140) and placebo (n = 159), 53.6% and 49.1%, respectively, had baseline Model for End-Stage Liver Disease (MELD) score ⩾ 12 and international normalized ratio (INR) ⩾ 1.2. Baseline ascites was observed in 36.4% (rifaximin) and 34.6% (placebo) of patients. In patients with MELD score ⩾ 12 and INR ⩾ 1.2, rifaximin reduced the relative risk (RR) of any first complication experienced during trial by 59% [hazard ratio (HR) = 0.41, 95% confidence interval (CI): 0.25–0.67; p \u3c 0.001] versus placebo. For patients with baseline ascites, rifaximin reduced the RR of any first complication experienced during trial by 42% versus placebo (HR = 0.58, 95% CI: 0.34–1.0; p = 0.045). For some subgroups, there was a decrease in RR of complications of SBP, variceal bleeding, and acute kidney injury/hepatorenal syndrome with rifaximin versus placebo, although there were few events reported in the study. Conclusion: Rifaximin may reduce the incidence of cirrhosis-related complications and the recurrence of overt HE. [ClinicalTrials.gov identifier: NCT00298038.

Gravitational memory of natural wormholes

A traversable wormhole solution of general scalar-tensor field equations is presented. We have shown, after a numerical analysis for the behavior of the scalar field of Brans-Dicke theory, that the solution is completely singularity--free. Furthermore, the analysis of more general scalar field dependent coupling constants indicates that the gravitational memory phenomenon may play an important role in the fate of natural wormholes.Comment: 14 pages revtex, 1 ps figur

Standardized cardiovascular magnetic resonance imaging (CMR) protocols, society for cardiovascular magnetic resonance: board of trustees task force on standardized protocols

<p/> <p>Index</p> <p><b>1. General techniques</b></p> <p>1.1. Stress and safety equipment</p> <p>1.2. Left ventricular (LV) structure and function module</p> <p>1.3. Right ventricular (RV) structure and function module</p> <p>1.4. Gadolinium dosing module.</p> <p>1.5. First pass perfusion</p> <p>1.6. Late gadolinium enhancement (LGE)</p> <p><b>2. Disease specific protocols</b></p> <p><b>2.1. Ischemic heart disease</b></p> <p>2.1.1. Acute myocardial infarction (MI)</p> <p>2.1.2. Chronic ischemic heart disease and viability</p> <p>2.1.3. Dobutamine stress</p> <p>2.1.4. Adenosine stress perfusion</p> <p><b>2.2. Angiography:</b></p> <p>2.2.1. Peripheral magnetic resonance angiography (MRA)</p> <p>2.2.2. Thoracic MRA</p> <p>2.2.3. Anomalous coronary arteries</p> <p>2.2.4. Pulmonary vein evaluation</p> <p><b>2.3. Other</b></p> <p>2.3.1. Non-ischemic cardiomyopathy</p> <p>2.3.2. Arrhythmogenic right ventricular cardiomyopathy (ARVC)</p> <p>2.3.3. Congenital heart disease</p> <p>2.3.4. Valvular heart disease</p> <p>2.3.5. Pericardial disease</p> <p>2.3.6. Masses</p

The analytic structure of heavy quark propagators

The renormalised quark Dyson-Schwinger equation is studied in the limit of the renormalised current heavy quark mass m_R --> infinity. We are particularly interested in the analytic pole structure of the heavy quark propagator in the complex momentum plane. Approximations in which the quark-gluon vertex is modelled by either the bare vertex or the Ball-Chiu Ansatz, and the Landau gauge gluon propagator takes either a gaussian form or a gaussian form with an ultraviolet asymptotic tail are used.Comment: 21 pages Latex and 5 postscript figures. The original version of this paper has been considerably extended to include a formalism dealing with the renormalised heavy quark Dyson-Schwinger equation and uses a more realistic Ansatz for the gluon propagator

Meson Mass Splittings in the Nonrelativistic Model

Mass splittings between isodoublet meson pairs and between $0^{-}$ and $1^{-}$ mesons of the same valence quark content are computed in a detailed nonrelativistic model. The field theoretic expressions for such splittings are shown to reduce to kinematic and Breit-Fermi terms in the nonrelativistic limit. Algebraic results thus obtained are applied to the specific case of the linear-plus-Coulomb potential, with resultant numbers compared to experiment.Comment: 29 pages with 2 tables and 4 figures, LBL-32872 and UCB-PTH-92/3

Phase transition and landscape statistics of the number partitioning problem

The phase transition in the number partitioning problem (NPP), i.e., the transition from a region in the space of control parameters in which almost all instances have many solutions to a region in which almost all instances have no solution, is investigated by examining the energy landscape of this classic optimization problem. This is achieved by coding the information about the minimum energy paths connecting pairs of minima into a tree structure, termed a barrier tree, the leaves and internal nodes of which represent, respectively, the minima and the lowest energy saddles connecting those minima. Here we apply several measures of shape (balance and symmetry) as well as of branch lengths (barrier heights) to the barrier trees that result from the landscape of the NPP, aiming at identifying traces of the easy/hard transition. We find that it is not possible to tell the easy regime from the hard one by visual inspection of the trees or by measuring the barrier heights. Only the {\it difficulty} measure, given by the maximum value of the ratio between the barrier height and the energy surplus of local minima, succeeded in detecting traces of the phase transition in the tree. In adddition, we show that the barrier trees associated with the NPP are very similar to random trees, contrasting dramatically with trees associated with the $p$ spin-glass and random energy models. We also examine critically a recent conjecture on the equivalence between the NPP and a truncated random energy model