Mathematical modelling of process of salt transfer under filtration and moisture transfer in saturated and non-saturated soil mass with available mobile free surface

Здійснено математичне моделювання процесу солепереносу при сумісній фільтрації підземних вод та вологопереносі в насичено-ненасиченому ґрунтовому середовищі. Розглянуто задачу безнапірної стаціонарної фільтрації сольових розчинів за наявності рухомої вільної поверхні ґрунтових вод, яка задана на межі областей повного та неповного насичення. Вважається, що сольові розчини находять у ґрунтове середовище з поверхні області неповного насичення і вимиваються через дрену (осушувальний режим). На основі побудованої математичної моделі даної крайової задачі проведено дослідження процесу солепереносу до дрени в області повного насичення та процесу вологопереносу з урахуванням солепереносу в області неповного насичення ґрунту; досліджено протікання даних процесів сумісно для обох областей водонасичення. Чисельні розв’язки відповідних крайових задач знайдено методом скінченних різниць із використанням чисельних конформних відображень. На основі програмної реалізації задачі проведено чисельні експерименти та здійснено їх аналіз.The mathematical modelling of the process of salt transfer under joint filtration of ground waters and moisture transfer in saturated-non-saturated soil medium has been carried out. The problem of the free flow stationary filtration of salt solutions under the available mobile free surface of ground waters which is set at the boundary of areas of complete and incomplete saturation has been considered. It is believed that salt solutions enter soil medium from the surface of incomplete saturation and are washed out via drain, i.e. the problem of salt transfer is considered in the case of drainage regime. On the basis of the built mathematical model of this boundary problem the research of the process of salt transfer to the drain in the area of complete saturation and of the process of moisture transfer taking into account salt transfer in the area of incomplete soil saturation has been conducted. The comprehensive study of the process of salt transfer in areas of complete and incomplete saturation is carried out. For this purpose these areas of water saturation are considered as one entity with common unknown boundary which is in the process of problem solution. It makes possible to find the interconnection between investigated processes and to carry out their prediction in the area of saturated-non-saturated soil medium. On the basis of the comprehensive solution of the problem the change of free surface under the influence of processes studied has been established. Numerical solutions of relevant boundary problems are determined by the method of finite differences using numerical conformal mapping. On the basis of programmed implementation of the problem the construction of the conformal mapping in areas of filtration flow, moisture flow and conformal differential network of the area of saturated-non-saturated soil medium has been done; there have been received numerical results and graphical representation of the distribution of the field of piezometric pressure heads, of moisture pressure heads and of concentration of salts in areas of complete and incomplete saturation and also of the distribution of the field of salt solutions concentration in saturated-non-saturated soil mass. A number of numerical experiments has been conducted which gave the possibility to carry out the analysis of results obtained with different initial data of the problem and to research in detail the nature of the action of the process of salt transfer under filtration and of moisture transfer in saturated-non-saturated soil medium

Magnetic field structure in single late-type giants: Beta Ceti in 2010 - 2012

The data were obtained using two spectropolarimeters - Narval at the Bernard Lyot Telescope, Pic du Midi, France, and ESPaDOnS at CFHT, Hawaii. Thirty-eight circularly-polarized spectra have been collected in the period June 2010 - January 2012. The Least Square Deconvolution method was applied for extracting high signal-to-noise ratio line profiles, from which we measure the surface-averaged longitudinal magnetic field Bl. Chromospheric activity indicators CaII K, H_alpha, CaII IR (854.2 nm) and radial velocity were simultaneously measured and their variability was analysed together with the behavior of Bl. The Zeeman Doppler Imaging (ZDI) inversion technique was employed for reconstruction of the large-scale magnetic field and two magnetic maps of Beta Ceti are presented for two periods (June 2010 - December 2010 and June 2011 - January 2012). Bl remains of positive polarity for the whole observational period. The behavior of the line activity indicators is in good agreement with the Bl variations. The two ZDI maps show a mainly axisymmetric and poloidal magnetic topology and a simple surface magnetic field configuration dominated by a dipole. Little evolution is observed between the two maps, in spite of a 1 yr interval between both subsets. We also use state-of-the-art stellar evolution models to constrain the evolutionary status of Beta Ceti. We derive a mass of 3.5 M_sun and propose that this star is already in the central-helium burning phase. Taking into account all our results and the evolutionary status of the star, we suggest that dynamo action alone may not be eficient enough to account for the high magnetic activity of Beta Ceti. As an alternate option, we propose that it may be an Ap star descendant presently undergoing central helium-burning and still exhibiting a remnant of the Ap star magnetic field.Comment: 10 pages; 5 figures; 3 table

The second Konus-Wind catalog of short gamma-ray bursts

In this catalog, we present the results of a systematic study of 295 short gamma-ray bursts (GRBs) detected by Konus-Wind (KW) from 1994 to 2010. From the temporal and spectral analyses of the sample, we provide the burst durations, the spectral lags, the results of spectral fits with three model functions, the total energy fluences and the peak energy fluxes of the bursts. We discuss evidence found for an additional power-law spectral component and the presence of extended emission in a fraction of the KW short GRBs. Finally, we consider the results obtained in the context of the Type I (merger-origin) / Type II (collapsar-origin) classifications.Comment: Accepted to the Astrophysical Journal Supplement Series (7 Figures, 8 Tables

The Magnetic Fields at the Surface of Active Single G-K Giants

We investigate the magnetic field at the surface of 48 red giants selected as promising for detection of Stokes V Zeeman signatures in their spectral lines. We use the spectropolarimeters Narval and ESPaDOnS to detect circular polarization within the photospheric absorption lines of our targets and use the least-squares deconvolution (LSD) method. We also measure the classical S-index activity indicator, and the stellar radial velocity. To infer the evolutionary status of our giants and to interpret our results, we use state-of-the-art stellar evolutionary models with predictions of convective turnover times. We unambiguously detect magnetic fields via Zeeman signatures in 29 of the 48 red giants in our sample. Zeeman signatures are found in all but one of the 24 red giants exhibiting signs of activity, as well as 6 out of 17 bright giant stars.The majority of the magnetically detected giants are either in the first dredge up phase or at the beginning of core He burning, i.e. phases when the convective turnover time is at a maximum: this corresponds to a 'magnetic strip' for red giants in the Hertzsprung-Russell diagram. A close study of the 16 giants with known rotational periods shows that the measured magnetic field strength is tightly correlated with the rotational properties, namely to the rotational period and to the Rossby number Ro. Our results show that the magnetic fields of these giants are produced by a dynamo. Four stars for which the magnetic field is measured to be outstandingly strong with respect to that expected from the rotational period/magnetic field relation or their evolutionary status are interpreted as being probable descendants of magnetic Ap stars. In addition to the weak-field giant Pollux, 4 bright giants (Aldebaran, Alphard, Arcturus, eta Psc) are detected with magnetic field strength at the sub-gauss level.Comment: 34 pages, 22 Figures, accepted for publication in Astronomy & Astrophysic

Human-machine networks: Towards a typology and profiling framework

© Springer International Publishing Switzerland 2016. In this paper we outline an initial typology and framework for the purpose of profiling human-machine networks, that is, collective structures where humans and machines interact to produce synergistic effects. Profiling a humanmachine network along the dimensions of the typology is intended to facilitate access to relevant design knowledge and experience. In this way the profiling of an envisioned or existing human-machine network will both facilitate relevant design discussions and, more importantly, serve to identify the network type. We present experiences and results from two case trials: a crisis management system and a peerto- peer reselling network. Based on the lessons learnt from the case trials we suggest potential benefits and challenges, and point out needed future work

The Main Directions in the Work of the Psychological Service at the University

Работа посвящена обобщению опыт работы психологической службы МПГУ. На основе анализа более 2500 индивидуальных консультаций, проведенных экспертами психологической службы в период с 2018 года по настоящее время, выделен спектр наиболее частых запросов, обозначены наиболее важные направления деятельности. Обоснована необходимость многопрофильности деятельности психологической службы вуза; в качестве основных направлений должны выступать консультативная помощь обучающимся и просветительская деятельность.The work is devoted to summarizing the experience of the Psychological Service of the Moscow State Pedagogical University. Based on the analysis of more than 2,500 individual consultations conducted by experts of the psychological service in the period from 2018 to the present, a range of the most frequent requests has been identified, and the most important areas of activity have been identified. The necessity of multidisciplinary activity of the psychological service of the university is substantiated; advisory assistance to students and educational activities should be the main directions