Encapsulation process sterilizes and preserves surgical instruments

Ethylene oxide is blended with an organic polymer to form a sterile material for encapsulating surgical instruments. The material does not bond to metal and can be easily removed when the instruments are needed

Process for preparing sterile solid propellants Patent

Using ethylene oxide in preparation of sterilized solid rocket propellants and encapsulating material

Plasma physics abstracts, 1 January 1966 through 31 December 1967

Bibliography containing 26 references with abstracts on plasma physics research, 1966-196

Apparent suppression of turbulent magnetic dynamo action by a dc magnetic field

Numerical studies of the effect of a dc magnetic field on dynamo action (development of magnetic fields with large spatial scales), due to helically-driven magnetohydrodynamic turbulence, are reported. The apparent effect of the dc magnetic field is to suppress the dynamo action, above a relatively low threshold. However, the possibility that the suppression results from an improper combination of rectangular triply spatially-periodic boundary conditions and a uniform dc magnetic field is addressed: heretofore a common and convenient computational convention in turbulence investigations. Physical reasons for the observed suppression are suggested. Other geometries and boundary conditions are offered for which the dynamo action is expected not to be suppressed by the presence of a dc magnetic field component.Comment: To appear in Physics of Plasma

Velocity field distributions due to ideal line vortices

We evaluate numerically the velocity field distributions produced by a bounded, two-dimensional fluid model consisting of a collection of parallel ideal line vortices. We sample at many spatial points inside a rigid circular boundary. We focus on ``nearest neighbor'' contributions that result from vortices that fall (randomly) very close to the spatial points where the velocity is being sampled. We confirm that these events lead to a non-Gaussian high-velocity ``tail'' on an otherwise Gaussian distribution function for the Eulerian velocity field. We also investigate the behavior of distributions that do not have equilibrium mean-field probability distributions that are uniform inside the circle, but instead correspond to both higher and lower mean-field energies than those associated with the uniform vorticity distribution. We find substantial differences between these and the uniform case.Comment: 21 pages, 9 figures. To be published in Physical Review E (http://pre.aps.org/) in May 200

A Self-Consistent Marginally Stable State for Parallel Ion Cyclotron Waves

We derive an equation whose solutions describe self-consistent states of marginal stability for a proton-electron plasma interacting with parallel-propagating ion cyclotron waves. Ion cyclotron waves propagating through this marginally stable plasma will neither grow nor damp. The dispersion relation of these waves, {\omega} (k), smoothly rises from the usual MHD behavior at small |k| to reach {\omega} = {\Omega}p as k \rightarrow \pm\infty. The proton distribution function has constant phase-space density along the characteristic resonant surfaces defined by this dispersion relation. Our equation contains a free function describing the variation of the proton phase-space density across these surfaces. Taking this free function to be a simple "box function", we obtain specific solutions of the marginally stable state for a range of proton parallel betas. The phase speeds of these waves are larger than those given by the cold plasma dispersion relation, and the characteristic surfaces are more sharply peaked in the v\bot direction. The threshold anisotropy for generation of ion cyclotron waves is also larger than that given by estimates which assume bi-Maxwellian proton distributions.Comment: in press in Physics of Plasma

Maternal smoking during pregnancy and appetite control in offspring

Aims: Intrauterine exposure to tobacco smoke products has been associated with long-term neurobehavioral effects. Modified appetite control might explain the recently observed association between maternal smoking during pregnancy and obesity in offspring. Methods: Some 10,557 British adults aged 42 years born between 3-9 March 1958 were followed up in a birth cohort study (NCDS). The main outcome measure was self-reported poor appetite at age 42 years and main exposure was maternal smoking during pregnancy. Results: The proportion of offspring with poor appetite increased with maternal smoking during pregnancy: nonsmoking 4.5%; (4.0% - 5.0%), medium smoking 5.6%; (4.5 % - 6.8 %), variable smoking 6.8 %; (4.9 % - 9.1 %) and heavy smoking 7.7 %; (6.3 % - 9.4 %). The unadjusted odds ratios for maternal smoking during pregnancy (ever/never) and poor appetite is 1.49 (1.25 - 1.77) and after adjustment for BMI at 42 years and other potential confounding factors it is 1.22 (1.07 - 1.48). Conclusions: Offspring of mothers who smoked during pregnancy were more likely to report a poor appetite independent of a number of potential confounding factors. Although not in the expected direction, the results suggest maternal smoking during pregnancy may influence appetite perception through a developmental influence or through confounding by social factors

Low magnetic Prandtl number dynamos with helical forcing

We present direct numerical simulations of dynamo action in a forced Roberts flow. The behavior of the dynamo is followed as the mechanical Reynolds number is increased, starting from the laminar case until a turbulent regime is reached. The critical magnetic Reynolds for dynamo action is found, and in the turbulent flow it is observed to be nearly independent on the magnetic Prandtl number in the range from 0.3 to 0.1. Also the dependence of this threshold with the amount of mechanical helicity in the flow is studied. For the different regimes found, the configuration of the magnetic and velocity fields in the saturated steady state are discussed.Comment: 9 pages, 14 figure

Asymptotic defectiveness of manufacturing plants: an estimate based on process learning curves

The paper describes a method for a preliminary estimation of asymptotic defectiveness of a manufacturing plant based on the prediction of its learning curve estimated during a p-chart setting up. The proposed approach provides process managers with the possibility of estimating the asymptotic variability of the process and the period of revision of p-chart control limits. An application of the method is also provided

Small scale structures in three-dimensional magnetohydrodynamic turbulence

We investigate using direct numerical simulations with grids up to 1536^3 points, the rate at which small scales develop in a decaying three-dimensional MHD flow both for deterministic and random initial conditions. Parallel current and vorticity sheets form at the same spatial locations, and further destabilize and fold or roll-up after an initial exponential phase. At high Reynolds numbers, a self-similar evolution of the current and vorticity maxima is found, in which they grow as a cubic power of time; the flow then reaches a finite dissipation rate independent of Reynolds number.Comment: 4 pages, 3 figure