5,362 research outputs found

    Helicity of convective flows from localized heat source in a rotating layer

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    Experimental and numerical study of the steady-state cyclonic vortex from isolated heat source in a rotating fluid layer is described. The structure of laboratory cyclonic vortex is similar to the typical structure of tropical cyclones from observational data and numerical modelling including secondary flows in the boundary layer. Differential characteristics of the flow were studied by numerical simulation using CFD software FlowVision. Helicity distribution in rotating fluid layer with localized heat source was analysed. Two mechanisms which play role in helicity generation are found. The first one is the strong correlation of cyclonic vortex and intensive upward motion in the central part of the vessel. The second one is due to large gradients of velocity on the periphery. The integral helicity in the considered case is substantial and its relative level is high

    Effects of picrotoxin on light adapted frog electroretinogram are not due entirely to its action in proximal retina

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    AbstractIn order to evaluate the site of action of picrotoxin (antagonist of ionotropic GABA receptors) on the electroretinographic (ERG) b- and d-waves, in this study we compared its effects on the intensity–response function of the ERG waves in intact light adapted frog eyecup preparations with its effects in eyecups, where the activity of proximal neurons was blocked by 1mMN-methyl-d-aspartate (MNDA). Picrotoxin markedly enhanced the b- and d-wave amplitude and slowed the time course of the responses at all stimulus intensities in the intact eyecups. Perfusion with NMDA alone caused significant enhancement of the b-wave amplitude and diminution of the d-wave amplitude without altering their time course in the entire intensity range. When picrotoxin was applied in combination with NMDA, an enhancement of the b-wave amplitude and slowing of its time course were observed at all stimulus intensities. The increase of the b-wave amplitude was significantly higher than that seen in NMDA group. Combined application of picrotoxin and NMDA caused an enhancement of the d-wave amplitude at the lower stimulus intensities and its diminution at the higher ones, while the d-wave time course was delayed over the entire intensity range. The results obtained indicate that a part of picrotoxin effects on the amplitude and time course of the photopic ERG b- and d-waves are due to its action in the distal frog retina

    Quality of the Solution Sets of Parameter-Dependent Interval Linear Systems

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    Introduction By R , R denote the set of real vectors with n components, resp. the set of real n matrices. The set of all real compact intervals [a] := [a, a] := {a # a} is denoted by IR. We assume the reader is familiar with interval arithmetic [1]. By IR , IR denote the sets of interval n-vectors, resp. n matrices. Consider the linear system x = b(p), (1) where A(p) and b(p) depend a#ne-linearly on a parameter vector p . When p varies within a range [p] , the set of solutions to all A(p) x = b(p), p [p], called parametric solution set, is := # (A(p), b(p), [p]) := x = b(p) for some p [p]} . Denote by [A] = [A, A] := A([p]) , resp. [b] = [b, b] := b([p]) the interval matrix, resp. the interval vector, obtained from A(p), resp. b(p), substituting p by [p] and performing the corresponding interval operations. Hence the interval linear system x = [b], that is A([p]) x = b([p]) is a general non-parametric interval l

    New programs for determining the main parameters of open clusters

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    A set of computer programs for the determination of the main parameters of open clusters, such as color excess, distance, and age, is developed. The set consists of two units. The first unit is designed to search for open clusters in wide fields using JHKs-photometry from various catalogs (2MASS, UKIDSS, VISTA) by identifying areas of high stellar density. The second unit determines the parameters of open clusters by fitting photometric diagrams. This is the unit described in the paper. Probable cluster members are identified by the proximity to the basic sequences on the J-(J - H) and Q-(J - H) diagrams. The color excess is determined by minimizing the deviations of Q values on the Q-(J - H) diagram. Ages and distance moduli are determined by comparing the color-magnitude diagrams with theoretical isochrones. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    Peculiarity of stellar kinematics in the solar vicinity

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    The peculiar velocities of nearby stars are studied. We determine the solar velocity components from the radial velocities and proper motions of stars and open clusters. We show that nearby stars are not very suitable for the determination of the solar motion components because of peculiarities in their velocity distribution. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    The formation of subjectivity and norms in the process of adaptation of young employees at the enterprise

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    The aim of the publication is to determine the interrelation of the formation of subjective qualities and norms process of adaptation of young employees at the enterprise.Methods. The research methodology involves a comprehensive combination of the theoretical analysis and the results of applied research at the enterprises of the Sverdlovsk region. The dialectical method and comparative analysis are used.Results and theoretical novelty. The questions of adaptation of young employees at the enterprise are considered. The concepts of «subjectivity» and «norms» in philosophy are analyzed. Subjectivity is presented as a personal basis of social activity of the young worker at the entity; regulations – as a method of adaptation of the personality, individual to that community in which it emerged to be. The characteristics of the youth working at the industrial enterprise are disclosed on the basis of socio-philosophical analysis; youth policy at the industrial enterprises is described; the formation of values and norms of young workers in the process of adapting the enterprise is observed. The personal subjectivity as the basis of social activity of the young worker in the enterprise is demonstrated. It is shown that relevance of subject qualities forming and regulations at youth is caused not only by the need of development of the identity of young workers, but also by economic safety of industrial enterprises wellbeing where their working career begins.Practical significance consists in the social-philosophical substantiation of interrelation of formation of subjective qualities and norms in the process of adaptation of young employees in the company, of the main provisions for the development of programs of adaptation of young employees at the enterprise; in providing the teaching social and humanitarian disciplines for bachelors and masters majoring in «Organization of Work with Youth». Цель изложенного в статье исследования – определить взаимосвязь формирования субъектных качеств и освоения индивидом корпоративных норм в процессе адаптации молодых работников на предприятии. Методология и методы. Методология работы состояла в комплексном сочетании теоретического анализа и результатов прикладных исследований на предприятиях Свердловской области. Использовались диалектический метод и сравнительный анализ данных. Результаты и теоретическая новизна. Рассмотрены аспекты адаптации молодых работников на предприятии. Раскрыта сущность философских понятий «субъектность» и «нормы». Субъектность представлена как личностная основа социальной активности молодого работника на предприятии; нормы – как способ адаптации личности, индивида к той общности, в которой он находится. На основе социально-философского анализа вскрыты особенности молодежи, работающей на промышленном предприятии; описана молодежная политика данных предприятий; прослежено становление ценностей молодых работников и присвоение ими в процессе адаптации норм, принятых на производстве. Продемонстрирована личностно развивающая природа соревнования, его роль в формировании субъектных качеств. Показано, что актуальность формирования субъектных качеств и норм у молодежи обусловлена не только необходимостью развития личности молодых работников, но и экономической безопасностью и благополучием промышленных предприятий, на которых начинается их трудовая биография. Практическая значимость исследования заключается в предложениях решения проблем реализации молодежной политики в промышленном секторе экономики. Материалы статьи могут служить базой для разработки программ адаптации молодых работников на предприятии и использоваться при преподавании социально-гуманитарных дисциплин для бакалавров и магистров по специальности «Организация работы с молодежью»

    Optical spectra, crystal-field parameters, and magnetic susceptibility of the new multiferroic NdFe3(BO3)4

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    We report high-resolution optical absorption spectra for NdFe3(BO3)4 trigonal single crystal which is known to exhibit a giant magnetoelectric effect below the temperature of magnetic ordering TN = 33 K. The analysis of the temperature-dependent polarized spectra reveals the energies and, in some cases, symmetries and exchange splittings of Nd3+ 84 Kramers doublets. We perform crystal-field calculations starting from the exchange-charge model, obtain a set of six real crystal-field parameters, and calculate wave functions and magnetic g-factors. In particular, the values g(perpendicular) = 2.385, g(parallel) = 1.376 were found for the Nd3+ ground-state doublet. We obtain Bloc=7.88 T and |JFN|= 0.48 K for the values of the local effective magnetic field at liquid helium temperatures at the Nd3+ site and the Nd - Fe exchange integral, respectively, using the experimentally measured Nd3+ ground-state splitting of 8.8 cm-1. To check reliability of our set of crystal field parameters we model the magnetic susceptibility data from literature. A dimer containing two nearest-neighbor iron ions in the spiral chain is considered to partly account for quasi-one-dimensional properties of iron borates, and then the mean-field approximation is used. The results of calculations with the exchange parameters for Fe3+ ions Jnn = -6.25 K (intra-chain interactions) and Jnnn = -1.92 K (inter-chain interactions) obtained from fitting agree well with the experimental data.Comment: 13 pages, 8 figures, 2 table
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