Renormalized theory of the ion cyclotron turbulence in magnetic field--aligned plasma shear flow

The analytical treatment of nonlinear evolution of the shear-flow-modified current driven ion cyclotron instability and shear-flow-driven ion cyclotron kinetic instabilities of magnetic field--aligned plasma shear flow is presented. Analysis is performed on the base of the nonlinear dispersion equation, which accounts for a new combined effect of plasma turbulence and shear flow. It consists in turbulent scattering of ions across the shear flow with their convection by shear flow and results in enhanced nonlinear broadening of ion cyclotron resonances. This effect is found to lead to the saturation of ion cyclotron instabilities as well as to the development of nonlinear shear flow driven ion cyclotron instability. 52.35.RaComment: 21 page

Phenomenological coefficients in solid-state diffusion: an Introduction

In this review, which is intended as an introduction to the subject, we introduce the phenomenological transport coefficients in solid-state diffusion and discuss their structure and physical meaning. Next, we discuss the Darken, the Manning, the Moleko, Allnatt and Allnatt and the Heumann expressions which relate the phenomenological coefficients to the (measurable) tracer diffusion coefficients. Finally, we discuss the relationships (sum-rules) among the phenomenological coefficients themselves in randomly mixed systems and note their applicability for simplifying collective diffusion problems

Carbon Interstitial Diffusion in gamma-Fe

n this paper, we employ a four-frequency model for carbon diffusion in austenite where interstitials can diffuse either as isolated species or pairs. We make use of the Okamura and Allnatt formalism that has recently been shown to be near exact. The general finding of a previous analysis of McKee is confirmed: the increase of both tracer and chemical carbon diffusion coefficients with carbon composition at 1000°C is largely a result of a much higher rate of rotation of an interstitial pair compared with isolated interstitials. However, we find that the carbon atoms move almost two times faster as a rotating pair than found originally by McKee

On decay of large amplitude bubble of disoriented chiral condensate

The time evolution of initially formed large amplitude bubble of disoriented chiral condensate (DCC) is studied. It is found that the evolution of this object may have a relatively long pre-decay stage. Simple explanation of such delay of the DCC bubble decay is given. This delay is related to the existence of the approximate solutions of multi-soliton type of the corresponding radial sine-Gordon equation in (3+1) dimensions at large bubble radius.Comment: 6 pages, LaTeX, 5 PostScript figure

Recent progress in the simulation of diffusion associated with hollow and Bi-metallic nanoparticles

In this paper, we review the recent understanding gained by kinetic Monte Carlo and molecular dynamics simulation and related theory of the diffusion processes involved in 1) the formation and later shrinkage of hollow nanoparticles and 2) the formation of segregated bi-metallic nanoparticles

Three-Dimensional Magnetohydrodynamics Simulations Of Counter-Helicity Spheromak Merging In The Swarthmore Spheromak Experiment

Recent counter-helicity spheromak merging experiments in the Swarthmore Spheromak Experiment (SSX) have produced a novel compact torus (CT) with unusual features. These include a persistent antisymmetric toroidal magnetic field profile and a slow, nonlinear emergence of the n = 1 tilt mode. Experimental measurements are inconclusive as to whether this unique CT is a fully merged field-reversed configuration (FRC) with strong toroidal field or a partially merged doublet CT configuration with both spheromak- and FRC-like characteristics. In this paper, the SSX merging process is studied in detail using three-dimensional resistive MHD simulations from the Hybrid Magnetohydrodynamics (HYM) code. These simulations show that merging plasmas in the SSX parameter regime only partially reconnect, leaving behind a doublet CT rather than an FRC. Through direct comparisons, we show that the magnetic structure in the simulations is highly consistent with the SSX experimental observations. We also find that the n = 1 tilt mode begins as a fast growing linear mode that evolves into a slower-growing nonlinear mode before being detected experimentally. A simulation parameter scan over resistivity, viscosity, and line-tying shows that these parameters can strongly affect the behavior of both the merging process and the tilt mode. In fact, merging in certain parameter regimes is found to produce a toroidal-field-free FRC rather than a doublet CT. (C) 2011 American Institute of Physics. [doi:10.1063/1.3660533

The Problem of Creative Organizational Leadership in Modern Russian Politics

This article is devoted to the one of the burning problems of politology: political leadership. The urgency of the problem is due to the fact that the country’s leadership has determined (including in the President’s Address to the Federal Assembly in 2018) the strategic course of Russia’s development as a long-term prosperity of the Russian society in the face of a tougher fight in the international arena. The implementation of this course largely depends on the ruling elite. In this connection, there is a need to develop a system for “cultivating” talented political leaders. In 2017, the presidential project “Leaders of Russia” started in our country. Considering that this project is at the initial stage of implementation, and also realizing the large-scale consequences of this project for the future of Russia, there is a need for a thorough iterative conceptual study of this project.A critical analysis of existing leadership concepts has been carried out and their limitations have been revealed to understand the specifics of this type of political leadership, which is characteristic for the long stable prosperity of large organized communities of people. The necessity of developing a new concept allowing to reveal the content of a modern form of effective political leadership is grounded.On the basis of system analysis, the author’s concept of political leadership in Russia is proposed. The starting point of the study is the theoretical proposition that in each period of the development of society there is an effective type of political leadership. It can be assumed that at the present stage of the development of Russian society, this type is creative organizational leadership. At the same time, the more there are organizational creative leaders in the ruling elite, the greater the likelihood of a sustained and sustained successful development of our society. The author’s descriptive dynamic model of creative organizational political leadership is presented

ОПРЕДЕЛЕНИЕ СУММАРНОГО СОДЕРЖАНИЯ ФЕНОЛЬНЫХ АН-ТИОКСИДАНТОВ В МОДЕЛЬНЫХ СМЕСЯХ ПО МЕТОДУ ФОЛИНА-ЧОКАЛЬТЕУ И ПО МЕТОДУ FRAP

The total content of phenolic antioxidants (PhA) in tea, wine and other foodstuffs is usually determined without their separation. Active oxidizing agents, mainly Folin-Ciocalteu reagent (FC), are used as group reagents. The results obtained with the FC assay and later recalculated to the standard substance vary significantly from the results obtained with the other spectrophotometric assays such as the FRAP assay. In order to elucidate the real reason of the above-mentioned discrepancies, the authors have analyzed the water solutions with the known PhA total content (10-5–10-4 mol/dm3). The correct results were obtained only for one-component solutions. For the model mixtures containing 2 or 3 components, the results of cΣ  measurement with the standard FC procedure were distorted with significant systematic errors. When the universally used standard (gallic acid) has been applied, the error values (δс) were positive to the point of 50 % rel.; for the other standards the corresponding errors were much greater (by modulo). The main source of systematic errors during the PhA total content estimation was an intragroup selectivity of the signals. This effect could be related to the reaction stoichiometry features when FC reacts with the individual polyphenols. The subsidiary source of the systematic errors was the non-additivity of the light absorbance by the reaction products (reduced forms of the FC-reagent). For some mixtures, the deviations from the additivity were near 20% rel., this effect was detected for the first time. The substitution of the FC reagent with a less active oxidizing agent (FRAP reagent: Fe3+ + 2,2'-dipyridil) during cΣdetermination depressed the intragroup selectivity of the signals and totally prevented the non-additivity of the light absorbance. These effects assured more correct estimates of the total PhA content (δс 25 %).  In addition, the FPAP assay was more sensitive and more specific method to determine the total polyphenols than the widely used FC assay. Therefore, authors recommend replacing the FC assay with the FRAP assay in the food industry to improve the quality control performance of tea, wines and other foodstuffs.Keywords: phenolic antioxidants, total content of polyphenols, spectrophotometry, model mixtures, Folin-Ciocalteu assay, FRAP assay, systematic errorsDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.008(Russian)V.I. Vershinin, E.V. Belova Dostoevsky Omsk State University, Mira str., 55a, Omsk, 644077, Russian FederationСуммарное содержание фенольных антиоксидантов (ФА) в пищевых продуктах обычно определяют без разделения смесей ФА, используя реактив Фолина-Чокальтеу (ФЧ) в качестве группового реагента. Как правило, результаты анализа, полученные методом ФЧ и выраженные в пересчете на стандартное вещество (Хст), намного выше результатов анализа тех же продуктов другими спектрофотометрическими методами, в частности методом FRAP (ferric reducing antioxidant power). Чтобы выяснить причины наблюдаемых расхождений, провели сопоставительный анализ водных растворов с известным содержанием ФА (10-5–10-4 моль/л). Методом ФЧ правильные результаты удается получить только в ходе анализа однокомпонентных растворов. Суммарное содержание ФА в модельных смесях методом ФЧ определяется с большими систематическими погрешностями (δс). При использовании галловой кислоты в качестве Хст значения δс доходят до 50 % отн., результаты анализа обычно завышены. Применение других Хст ведет к еще большим (по модулю) погрешностям. Установлено, что главным источником этих погрешностей является внутригрупповая селективность сигналов, вероятно обусловленная разной стехиометрией окисления индивидуальных ФА. Дополнительным источником погрешностей является неаддитивность светопоглощения продуктов восстановления реактива ФЧ смесями ФА; этот эффект выявлен впервые. Для некоторых смесей отклонения от аддитивности (ОА) доходят до 20 %. Таким образом, независимо от природы выбранного стандарта метод ФЧ не позволяет правильно оценить суммарное содержания ФА в неразделенных смесях. Переход к методу FRAP (система Fe3+ + 2,2'-дипиридил) обеспечил снижение внутригрупповой селективности и аддитивность сигналов. Анализ модельных смесей ФА по методу FRAP дает более правильные результаты (δс 25%). Кроме того, метод FRAP более чувствителен и более специфичен для данной группы аналитов. Поэтому замена метода ФЧ методом FRAP должна повысить надежность контроля качества чая, вин и других пищевых продуктов по показателю «суммарное содержание полифенолов».   Ключевые слова: фенольные антиоксиданты, суммарное содержание полифенолов, модельные смеси, спектрофотометрия, метод Фолина-Чокальтеу, метод FRAP, систематические погрешности.DOI: http://dx.doi.org/10.15826/analitika.2019.23.3.00