Polygaussian Approximation and Adaptive Processing of an Electrocardiographic Signal Against Interference Background

We present the results of a study and substantiation of the method of polygaussian approximation of an electrocardiographic (ECG) signal against interference background during computer analysis of that signal. It is proposed to use adaptive processing of ECG signals, which allows one to increase the signal-to-interference ratio by over 7 dB.     

Atroposelective Synthesis of Axially Chiral N‐Arylpyrroles by Chiral‐at‐Rhodium Catalysis

A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral‐at‐metal rhodium Lewis acid. Specifically, N‐arylpyrroles were alkylated with N‐acryloyl‐1H‐pyrazole electrophiles in up to 93 % yield and with up to >99.5 % ee, and follow‐up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.     

Highly resolved fluid flows: "liquid plasmas" at the kinetic level

Fluid flow around an obstacle was observed at the kinetic (individual particle) level using "complex (dusty) plasmas" in their liquid state. These "liquid plasmas" have bulk properties similar to water (e.g., viscosity), and a comparison in terms of similarity parameters suggests that they can provide a unique tool to model classical fluids. This allows us to study "nanofluidics" at the most elementary-the particle-level, including the transition from fluid behavior to purely kinetic transport. In this (first) experimental investigation we describe the kinetic flow topology, discuss our observations in terms of fluid theories, and follow this up with numerical simulations.     

Concentration dependence of the viscosity of <Emphasis Type="Italic">tert</Emphasis>-butanol-water mixtures: Physical experiment and computer simulation

The concentration dependence of the viscosity of tert-butanol-water mixtures in the range of tert-butanol mole fractions from 0 to 0.02 was studied experimentally and by computer simulation. The methods of potentials of mean force and statistical geometry were successfully applied to analysis of physical factors responsible for the extrema in the composition-property dependences. The maximum in the concentration dependence of the viscosity is due to association of solvent molecules.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1250–1256.Original Russian Text Copyright © 2004 by Lukyanchikova, Ivlev, Kiselev, Alper.This revised version was published online in April 2005 with a corrected cover date.     

Scattering in the attractive Yukawa potential in the limit of strong interaction

Scattering in the attractive screened Coulomb (Yukawa) potential in the limit of strong interaction is investigated. It is shown that the scattering occurs mostly with large angles. The corresponding momentum-transfer cross section is calculated. The results are applied to estimate the ion drag force acting on an isolated micron-sized grain in low-pressure bulk plasmas.