Study of "racemic compound-like" behavior of diastereomeric mixture of pinanyl sulfoxides by x-ray diffraction, ir spectroscopy, and DFT calculations

The oxidation of a β-hydroxysulfide in the pinane series by use of mchloroperbenzoic acid resulted in the formation of the corresponding β-hydroxysulfoxide as a mixture of two diastereomers in 4:5 ratio. According to single-crystal X-ray diffraction (XRD) results, it is established that the diastereomeric mixture of sulfoxides crystallizes in the "racemic compound-like" manner under formation of asymmetric dimers through S=O··H-O interactions. This asymmetric dimer formed from diastereomeric molecules is a structural unit in both crystal modifications, the triclinic and the monoclinic one. The behavior of the diastereomeric mixture of pinane derived sulfoxides in crystals, melts and in tetrachloromethane solutions was studied by IR spectroscopy. The density functional theory (DFT) method with 6-31G (d, p) basis set was used to calculate the optimized geometrical parameters and vibrational frequencies of different associates in solution. The calculated vibrational frequencies are compared with experimental IR spectra. Copyright © 2014 Taylor & Francis Group, LLC

Совершенствование научно-методических подходов в области метрологического обеспечения технологий контроля герметичности на опасных производственных объектах

In this article the analysis of metrological assurance of control technologies integrity subject to the rules of safety at hazardous production facilities. Deals with the scientific and methodological aspects of the evaluation of threshold sensitivity of control systems integrity using controlled leaks, containing in its composition of standard samples for reproduction of units of volumetric and mass flow of gas, which expands the scope of their applicability.В настоящей статье проводится анализ метрологического обеспечения технологий контроля герметичности с учетом правил безопасности на опасных производственных объектах. Рассматриваются научные и методические аспекты оценки пороговой чувствительности систем контроля герметичности с использованием контрольных течей, содержащих в своем составе стандартные образцы воспроизведения единиц объемного и массового расходов газа, что расширяет сферу их применимости

Design, construction, quality control and performance study with cosmic rays of modules for the LHCb electromagnetic calorimeter

Abstract This article addresses the design and construction of modules for the LHCb electromagnetic calorimeter. Quality control and preinstallation tests, including cells pre-calibration, are described and the results of light yield measurements are given

Experimentally investigating efficiency of using the catalytic blocks in a small N2O gas-generators with resonant initiation system

The object of research work are small gasifiers (SGF ) to nitrous oxide(N2O) gas-dynamic resonance system (GRS) initiate the workflow. Subject of research - methods to improve the efficiency of the SGF . Relevance of the work is determined by what is currently on the SGF as nitrous oxidemonopropellant are widely used in aerospace engineering, in particular in various power plant and increasing the efficiency of decomposition of N2O is an important scientific and technical challenge .Duty cycle begins after the SGF through the nozzle GRS gas N2O. At a certain ratio geometrical and operational parameters of the SGF in the area of the nozzle is formed GRS unstable region gasdynamic flow consisting of "holes" and the Mach disk . In the case where the Mach disk is localized in the leading edge cavity , mounted coaxially with the nozzle GRS longitudinal oscillations occur supported kinetic energy of the feed gas . In this case, stagnant zone of the resonator is carried out intensive heating nitrous oxidegas . The heat release is due to the high frequency of the cyclic process of transmission and reflection from the end wall of the cavity shock waves (SW) . The high temperature level in the resonant cavity causes the thermal decomposition of N2O with the evolution of heat and the spread of this upstream process and then run the SGF .The aim is to improve the methods of experimental study of the effectiveness of the SGF with the GRS , including the use of catalytic converters and original heating nitrous oxide. The objectives of the study is to determine the characteristics , comparative analysis and synthesis of the results obtained for the three variants of the GRS (without catalytic converters , with the end surface of the cavity of the catalytic material , the end surface of the cavity of the catalytic material and the catalyst unit IDI ) when the initial temperature of N2O in the range of initial temperature 300 ... 600 K.The paper presents a diagram of the experimental facility and stand for research, as well as the method of determining the completeness of the decomposition of nitrous oxideand time- SGF nominal mode . The proposed technique is to identify performance indicators based on spectrogram analysis of pressure fluctuations , which can be obtained by Fourier transformation . Application spectrograms to analyze the characteristics of the workflow is advisable in cases where high levels of temperatures do not allow direct measurements or these measurements associated with certain technical difficulties caused by small dimensions and operating conditions of the SGF .In accordance with the results obtained , we can draw the following conclusions . Use of the catalyst of the end wall of the cavity is an effective method of intensifying the decomposition N2O, which reduces the time for the output mode is more than 35 %. Installing the pre- catalyst unit can further accelerate out SGF mode and increase by 5 ... 7% completeness decomposition N2O. Increasing the initial temperature of nitrous oxidehas a positive effect on the efficiency of the SGF , helping to reduce time-to- nominal conditions , as well as increase the completeness of decomposition N2O. These methods of intensifying the process of decomposition of nitrous oxidetechnological, functional and can be used for various purposes in the SGF . In particular they can be used in industrial plants for gas-dynamic spraying , cutting and blasting abrasive cleaning materials, as well as devices to start propulsion energy and high power.This work was supported by RFBR under grant 14-08-01118.</p