Plasma probe characteristics in low density hydrogen pulsed plasmas

Probe theories are only applicable in the regime where the probe's perturbation of the plasma can be neglected. However, it is not always possible to know, a priori, that a particular probe theory can be successfully applied, especially in low density plasmas. This is especially difficult in the case of transient, low density plasmas. Here, we applied probe diagnostics in combination with a 2D particle-in-cell model, to an experiment with a pulsed low density hydrogen plasma. The calculations took into account the full chamber geometry, including the plasma probe as an electrode in the chamber. It was found that the simulations reproduce the time evolution of the probe IV characteristics with good accuracy. The disagreement between the simulated and probe measured plasma density is attributed to the limited applicability of probe theory to measurements of low density pulsed plasmas. Indeed, in the case studied here, probe measurements would lead to a large overestimate of the plasma density. In contrast, the simulations of the plasma evolution and the probe characteristics do not suffer from such strict applicability limits. These studies show that probe theory cannot be justified through probe measurements

Geometric phase and o-mode blue shift in a chiral anisotropic medium inside a Fabry-P\'erot cavity

Anomalous spectral shift of transmission peaks is observed in a Fabry--P\'erot cavity filled with a chiral anisotropic medium. The effective refractive index value resides out of the interval between the ordinary and the extraordinary refractive indices. The spectral shift is explained by contribution of a geometric phase. The problem is solved analytically using the approximate Jones matrix method, numerically using the accurate Berreman method and geometrically using the generalized Mauguin--Poincar\'e rolling cone method. The $o$-mode blue shift is measured for a 4-methoxybenzylidene-4'-$n$-butylaniline twisted--nematic layer inside the Fabry--P\'erot cavity. The twist is electrically induced due to the homeoplanar--twisted configuration transition in an ionic-surfactant-doped liquid crystal layer. Experimental evidence confirms the validity of the theoretical model.Comment: the text is available both in English (Timofeev2015en.tex) and in Russian (download: other formats - source - Timofeev2015ru.tex, Timofeev2015rus.pdf

Experimental observation of spontaneous spin polarization of electrons in hybridized states of transition element impurities in semiconductors

Experimental evidence of the possible existence of spontaneous spin polarization of the electron system in hybridized states formed by transition element impurity atoms in the conduction band of semiconducting crystals is examined. The details of a quantitative interpretation of experiments on the temperature dependence of the specific heat and elastic moduli of mercury selenide crystals with iron impurities confirm the feasibility of establishing the presence of electron spin polarization in this type of experiment, as well as the possible existence of polarization in the crystals studied here. Theoretical arguments support the observation of a thermodynamic anomalous Hall effect owing to spontaneously polarized donor electrons from low-concentration impurities. © 2013 AIP Publishing LLC

Investigation of contamination caused by rubber compactor in arsine purified in gas centrifuge

In the process of studying the application of gas centrifuges for deep purification of arsine from impurities sulphur was found. Estimation of quantitative content of sulphur in pure arsine showed the value -10-4 wt. %. The sources of sulphur was stated to be rubber compactors forming gas centrifuge complex and made from rubber on the basis of butadiene_nitrile caoutchouc using sulfur cure. Using rubber compactors made from rubber produced from fluoroelastomers, not undergoing to sulfur cure one can provide sulphur content in pure product less than 10-5 wt. %

Methodological Approaches to Studying Fatal Adverse Drug Reactions

Serious adverse drug reactions (ADRs) to medicinal products can cause death. It is an immediate challenge for modern medicine to prevent the possibility of this outcome and to improve the safety of pharmacotherapy. The aim of this study was to identify and analyse the main methodological approaches to studying the prevalence, patterns, and risk factors of fatal ADRs. The authors identified three main methods for studying such reactions: analysis of death certificates, monitoring of spontaneous reports, and review of clinical trials with a particular focus on safety. Each of these methods has its advantages and limitations. Clinical trials provide the most accurate information on the prevalence of fatal ADRs. For inpatients, this value ranged from 0.05 to 0.95% of the total number of hospital admissions. Data from death certificates may be particularly useful for identifying the groups of medicinal products posing a high risk of death and for making longitudinal comparisons. Monitoring of spontaneous reports is very effective in rapidly identifying fatal adverse reactions to new medicinal products. According to the authors, not only the choice of a data collection method, but also its application can affect the results of an ADR study. It was noted that the data varied across clinical trials conducted in different countries. Such variations indicate the importance of studying the problem of fatal ADRs at the national level, as well as the need for initiating such studies in the Russian Federation

Synthesis of Pah-Containing Copolymers on the Basis of Acrylic Acid

This work was funded by Russian Science Foundation (Ref no. 18-73-00301)

Perylene-3-carbaldehyde and Perylen-3-Ylmethanol: Syntheses and Spectral-Fluorescent Studies of the Liposome Loading

The authors acknowledge the Russian Science Foundation (Ref. № 18-73-00301) for funding

Benzyne-mediated rearrangement of 3-(2-pyridyl)-1,2,4-triazines into 10-(1H-1,2,3-triazol-1-yl)pyrido[1,2-a]indoles

The reaction between 5-R-6-R1-3-(2-pyridyl)-1,2,4-triazines and benzyne generated in situ in toluene under reflux results in the formation of 10-(1H-1,2,3-triazol-1-yl)pyrido[1,2-a]indoles 3 in up to 60% yields instead of the expected 3-R-4-R1-1-(2-pyridyl)isoquinolines 2. The crystal structure of product 3c and the proposed mechanism for the formation of 3 are reported. © 2013 Elsevier Ltd. All rights reserved

A rational protocol for the synthesis of 1-(2-pyridyl)isoquinolines

Aza-Diels-Alder reaction between 3-(2-pyridyl)-1,2,4-triazines and 1-morpholinocyclohexene followed by aromatization of the cyclohexene moiety affords 1-(2-pyridyl)isoquinolines. Crystal structures of two tetrahydroisoquinolines were confirmed by X-ray diffraction analysis. © 2013 Mendeleev Communications. All rights reserved

Effect of Fermi-liquid interactions on the low-temperature de Haas - van Alphen oscillations in quasi-two-dimensional conductors

In this work we present the results of theoretical analysis of the de Haas-van Alphen oscillations in quasi-two-dimensional conductors. We have been studying the effect of the Fermi-liquid correlations of charge carriers on the above oscillations. It was shown that at reasonably low temperatures and weak electron scattering the Fermi-liquid interactions may cause noticeable changes in both amplitude and shape of the oscillations even at realistically small values of the Fermi-liquid parameters. Also, we show that the Fermi-liquid interactions in the system of the charge carriers may cause magnetic instability of a quasi-two-dimensional conductor near the peaks of quantum oscillations in the electron density of states at the Fermi surface, indicating the possibility for the diamagnetic phase transition within the relevant ranges of the applied magnetic fields.Comment: 10 pages, 4 figure