Defect parameters for strontium fluoride

The ionic conductivity of dilute Sr₁?xYb_xF₂+x solid solutions has been studied as a function of temperature. For the migration enthalpy of fluoride interstitials the value 0.946 eV is obtained, and the value 0.56 eV for the dissociation enthalpy of neutral associates (Yb_SrF_i)^x. The latter value is concordant with the theoretical binding energy for this type of associate. A re-analysis of the conductivity data for SrF₂ leads to the value 2.70 eV for intrinsic defect formation, contrary to reported values which range from 2.2 to 2.3 eV.     

Observation of velocity-independent electron transport in the reversed field pinch

Confinement of runaway electrons has been observed for the first time in a reversed field pinch during improved-confinement plasmas in the Madison Symmetric Torus. Energy-resolved hard-x-ray flux measurements have been used to determine the velocity dependence of the electron diffusion coefficient, utilizing computational solutions of the Fokker-Planck transport equation. With improved-confinement, the fast electron diffusivity drops by 2 orders of magnitude and is independent of velocity. This suggests a change in the transport mechanism away from stochastic magnetic field diffusion.     

A novel synthesis of N-(piperidin-4-yl)-1,3-dihydroindol-2-one via an intramolecular Pd-catalyzed amination

A novel efficient synthetic route to the pharmaceutical key intermediate N-(piperidin-4-yl)-1,3-dihydroindol-2-one is described. The key step involves a high-yielding intramolecular palladium-catalyzed amination reaction using Buchwald’s X-Phos ligand under mild reaction conditions.     

Spectroscopic observation of fluctuation-induced dynamo in the edge of the reversed-field pinch

The fluctuation-induced dynamo has been investigated by direct measurement of v and b in the edge of a reversed-field pinch and is found to be significant in balancing Ohm's law. The velocity fluctuations producing the dynamo emf have poloidal mode number m = 0, consistent with MHD calculations and in contrast with the core m = 1 dynamo. The velocity fluctuations exhibit the parity relative to their resonant surface predicted by linear MHD theory.     

Good practice in the use of noise mapping software

After over 20 years of development, noise mapping software is, today, a professional tool that is widely used by many people with different backgrounds and experience in the applications, the data and the software used. The user has the possibility to influence the quality of the result of the noise mapping process. The major factors affecting good practice include:

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  the user’s knowledge of the standard,

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  the user’s knowledge of the software,

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  documentation of software functions and its implementation of the standard,

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  quality assurance of software implementation,

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  documentation of software settings in calculation results,

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  the user’s analysis of the quality and impact of the input data.

Several methods are available to ensure good practice and improve the quality of output through such methods as standardization and documentation, training and user certification. For example, in 2006, the European Commission Working Group Assessment of Exposure to Noise produced the “Good Practice Guide for Strategic Noise Mapping and the Production of Associated Data on Noise Exposure” Version 2.This article will describe the major factors where user influences the quality of the results and the methods to ensure good practice and improving the quality of output.     

An efficient synthesis of 4-bromo-N-substituted oxindoles by an intramolecular copper-catalyzed amidation reaction

A highly efficient synthetic approach to novel 4-bromo-N-substituted oxindoles is described. The method involves a mild intramolecular copper-catalyzed amidation reaction of N-substituted 2,6-dibromophenylacetamides. In contrast to our recently published palladium-catalyzed amidation reaction, no concomitant dimerization on the 3-position of the formed oxindole occurs.