Виртуальное сообщество: формирование каналов виртуального общения институциональной корпорации в сфере высшего образования

Results of philosophical research devoted to studying of virtual communities are considered in article. The author gives an example effective cooperation in virtual communities these are virtual communications in scientifically-educational sphere - higher education web-sites, professional forums, teleconferences. Studying a phenomenon of virtual communities (phylosophical position) has allowed to reveal increasing value of this work and open participation of people in modern virtual communications.Рассмотрены результаты философского исследования, посвященного изучению виртуальных сообществ. Автор приводит примеры эффективного сотрудничества в виртуальных сообществах – это виртуальная коммуникация в научно-образовательной сфере: веб-сайты, профессиональные форумы, телеконференции. Изучение феномена виртуальных сообществ (с философской точки зрения) позволило выявить увеличивающуюся ценность данной работы и открытого участия людей в современном виртуальном общении

Selective recovery of tropane alkaloids applying liquid membrane technique

A tropine recovery from its solutions applying a liquid membrane technique was studied. Among several studied organic solvents, chloroform showed best extraction ability towards atropine. Pertraction studies were carried out in a laboratory bulk liquid membrane contactor with agitation of all three phases. Both, aqueous solutions of pure atropine and extract of Atropa Belladonna L. roots were used as feed solutions, as well as chloroform and diluted sulphuric acid as a liquid membrane and a stripping liquor, respectively. The effect of phase agitation on alkaloid pertraction was studied for the cases when pure atropine solutions were used as feed phase. A pertraction process carried out with native liquid extracts from A. Belladonna provided selective alkaloid recovery and its concentration in the acceptor solutio

Analytical solution to the equations of a two-phase layer with allowance for the convective heat and mass transfer in a binary liquid

The model equations describing directional crystallization of a binary system with a two-phase layer and taking into account the convective heat and mass transfer mechanism in the liquid phase are formulated. The system of formulated nonlinear heat and mass transfer equations is solved analytically in the case of steady-state crystallization scenario. The temperature and concentration distributions, the solid phase fraction, the two-phase layer thickness and its boundaries, solid phase - mushy layer and mushy layer - liquid phase, are found. The steady-state crystallization velocity is determined as a function of fixed model parameters. The developed model and its analytical solutions describe the case of intensive motions of a binary liquid (the case of turbulent flows in the ocean, for example). © 2019 Author(s)

Analytical solutions of mushy layer equations describing directional solidification in the presence of nucleation

The processes of particle nucleation and their evolution in a moving metastable layer of phase transition (supercooled liquid or supersaturated solution) are studied analytically. The transient integro-differential model for the density distribution function and metastability level is solved for the kinetic and diffusionally controlled regimes of crystal growth. The Weber–Volmer–Frenkel–Zel’dovich and Meirs mechanisms for nucleation kinetics are used. We demonstrate that the phase transition boundary lying between the mushy and pure liquid layers evolves with time according to the following power dynamic law: at + eZ1(t), where Z1(t) = ßt7/2 and Z1(t) = ßt2 in cases of kinetic and diffusionally controlled scenarios. The growth rate parameters a, ß and e are determined analytically. We show that the phase transition interface in the presence of crystal nucleation and evolution propagates slower than in the absence of their nucleation. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’. © 2018 The Author(s) Published by the Royal Society. All rights reserved.Российский Фонд Фундаментальных Исследований (РФФИ), RFBRData accessibility. This article has no additional data. Authors’ contributions. All authors contributed equally to the present research article. Competing interests. The authors declare that they have no competing interests. Funding. This work was supported by project no. 16-08-00932 from the Russian Foundation for Basic Research

On the theory of the unsteady-state growth of spherical crystals in metastable liquids

Motivated by a large number of applications, we consider the process of non-stationary growth of spherical crystals in a supercooled binary melt. The moving-boundary problem describing the unsteadystate distributions of temperature and impurity concentration around the growing crystal as well as the dynamics of its radius and growth rate is solved by means of the methods of small-parameter expansion and Laplace-Carson integral transform. We show that the growth rate of crystals contains the main contribution (which is proportional to the supercooling degree) and the first correction (which is proportional to 2t, where t is time). The second correction is also found. The non-stationary temperature and concentration fields are determined as power functions of and t. We demonstrate that the first corrections to the dynamics of crystal radius R(t) and its growth rate V(t) play an important role. It is shown that R(t) andV(t) can change more than twice in comparison with the previously known steady-state solution with the course of time. Such a behaviour will significantly modify the dynamics of a polydisperse ensemble of crystals evolving in a metastable liquid. This article is part of the theme issue 'Heterogeneous materials: Metastable and non-ergodic internal structures'. ©2019 The Author(s) Published by the Royal Society

The Role of Technology in the Development of the Russian Poster: from Photomontage to Digital Printing

В статье рассматривается роль технологий в развитии русского плаката и их влияние на инструментарий графического дизайнера от конструктивизма до современности.The article examines the role of technologies in the development of the Russian poster and their impact on the tools of the graphic designer from constructivism to modernity

From nucleation and coarsening to coalescence in metastable liquids

The transition of a metastable liquid (supersaturated solution or supercooled melt) occurring from the intermediate stage (where the crystals nucleate and grow) to the concluding stage (where the larger particles evolve at the expense of the dissolution of smaller particles) is theoretically described, with allowance for various mass transfer mechanisms (reaction on the interface surface, volume diffusion, grain-boundary diffusion, diffusion along the dislocations) arising at the stage of Ostwald ripening (coalescence). The initial distribution function (its 'tail') for the concluding stage (forming as a result of the evolution of a particulate assemblage during the intermediate stage) is taken into account to determine the particle-size distribution function at the stage of Ostwald ripening. This modified distribution function essentially differs from the universal Lifshitz-Slyozov (LS) solutions for several mass transfer mechanisms. Namely, its maximum lies below and is shifted to the left in comparison with the LS asymptotic distribution function. In addition, the right branch of the particle-size distribution lies above and is shifted to the right of the LS blocking point. It is shown that the initial 'tail' of the particle-size distribution function completely determines its behaviour at the concluding stage of Ostwald ripening. The present theory agrees well with experimental data. © 2020 The Author(s) Published by the Royal Society. All rights reserved.Russian Science Foundation, RSF: 18-19-00008Data accessibility. This article has no additional data. Authors’ contributions. All authors contributed equally to the present research article. Competing interests. The authors declare that they have no competing interests. Funding. This work was supported by the Russian Science Foundation (grant no. 18-19-00008)

Examination of evidence for collinear cluster tri-partition

In a series of the experiments at different time-of-flight spectrometers of heavy ions we have observed manifestations of a new at least ternary decay channel of low excited heavy nuclei. Due to specific features of the effect, it was called collinear cluster tri-partition (CCT). The experimental results obtained initiated a number of theoretical articles dedicated to different aspects of the CCT. We compare theoretical predictions with our experimental data, only partially published so far. The model of one of the most populated CCT modes that gives rise to the so called "Ni-bump" is discussed. Detection of the 68-72Ni fission fragments with a kinetic energy E<25 MeV at the mass-separator Lohengrin is proposed for an independent experimental verification of the CCT.Comment: 16 pages, 14 figure