Microsecond long atomistic simulation of supercooled water

Supercooled water is a metastable phase of liquid water below the melting temperature. An interesting discussion recently developed on the relationship between crystallization rate and the time scales of equilibration within the liquid phase. Calculations using a coarse grained monatomic model of water, the mW model, suggested that equilibration of the liquid below the temperature of homogeneous nucleation $T_H\approx225$ K is slower than ice nucleation. Here, a 3 $\mu$s long molecular dynamics simulation of the TIP4P-Ew water model is presented to investigate the relaxation properties of an atomistic model in the supercooled region below $T_H$. Evidence is provided that the liquid phase of the TIP4P-Ew model is at equilibrium in the supercooled regime before ice nucleation.Comment: 2 pages, 2 figure

Pasting of two one-dimensional diffusion processes

By the method of classical potential theory we obtain an integral representation of the two-parameter semigroup of operators that describes an inhomogeneous Feller process on a line that is a result of pasting together two diffusion processes with the nonlocal boundary condition of non-transversal type

Geomagnetic Survey Interpolation with the Machine Learning Approach

This paper portrays the method of UAV magnetometry survey data interpolation. The method accommodates the fact that this kind of data has a spatial distribution of the samples along a series of straight lines (similar to maritime tacks), which is a prominent characteristic of many kinds of UAV surveys. The interpolation relies on the very basic Nearest Neighbours algorithm, although augmented with a Machine Learning approach. Such an approach enables the error of less than 5 percent by intelligently adjusting the Nearest Neighbour algorithm parameters. The method was pilot tested on geomagnetic data with Borok Geomagnetic Observatory UAV aeromagnetic survey data

MODELLING THE HORIZONTAL VELOCITY FIELD OF THE NIZHNE-KANSK MASSIF ACCORDING TO GNSS OBSERVATIONS

Within the boundaries of the Nizhne-Kansk granite-gneiss massif, which directly borders on the Atamanovskiy branch of the Yenisei Ridge, the building of an underground research laboratory for validating the safety of disposal of high-level radioactive waste began in 2019. In 2010, researchers of the Mining and Chemical Combine at Zheleznogorsk and the Geophysical Center, Russian Academy of Sciences, organized a satellite geodetic network within the boundaries of the Nizhne-Kansk massif; this network included 30 GNSS stations intended for observations of modern crustal movements.The purpose of this study is to determine vectors and simulate the field of horizontal modern crustal movements from measurements made in 2010 - 2019. The tasks included: creating a catalogue of displacement data; calculating and estimating horizontal velocities of modern crustal movements, modelling the horizontal velocity field using artificial neural networks, developing a kinematic model of the area and comparing it with geological survey data.As a result, the resulting model was found to be in good agreement with the results of structural-geological and geodynamic studies in the area. The rate of convergence between the Siberian Platform and the West Siberian Plate in the interaction zone of the southern part of the Yenisei Ridge can be estimated as 2-4 mm/year. The movements of the selected area are due to sublatitudinal compression along an azimuth of 100-110 degrees. Within the selected tectonic blocks relatively low rates of modern horizontal movements of the earth's crust were obtained, which confirms the stable geodynamic regime of the structural block hosting the underground research laboratory. Thus, the results of the work demonstrate the possibility of disposal of high-level radioactive waste in the selected structural block.

Towards a microscopic description of the free-energy landscape of water

Free-energy landscape theory is often used to describe complex molecular systems. Here, a microscopic description of water structure and dynamics based on configuration-space-networks and molecular dynamics simulations of the TIP4P/2005 model is applied to investigate the free-energy landscape of water. The latter is built on top of a large set of water microstates describing the kinetic stability of local hydrogen-bond arrangements up to the second solvation shell. In temperature space, the landscape displays three regions with an overall different organization. At ambient conditions, the free-energy surface is characterized by structural inhomogeneities with multiple, structurally well defined, short-lived basins of attraction. Below around ambient temperature, the liquid rapidly becomes homogeneous. In this regime, the landscape is funneled-like, with fully-coordinated water arrangements at the bottom of the funnel. Finally, a third region develops below the temperature of maximal compressibility (Widom line) where the funnel becomes steeper with few interconversions between microstates other than the fully coordinated ones. Our results present a viable a way to manage the complexity of water structure and dynamics, connecting microscopic properties to its ensemble behavior

Месенджер Telegram для забезпечення навчального процесу в умовах карантинних обмежень

The article is devoted to the problem of using Telegram messenger in the educational process in supporting the higher school under the conditions of forced quarantine restrictions due to the Covid-19 pandemic. Modern messengers (Telegram, Viber, Facebook Messenger, WhatsApp) are analyzed via pre-defined criteria (commerciality, functionality, architecture, security) and the range of indicators, the benefits of using Telegram messenger to support the educational process are outlined. The essence, benefits, and possibilities of using Telegram ChatBot are characterized. The main steps for creating Telegram ChatBot are described. Recommendations are provided to improve the pedagogical effect of using Telegram ChatBots. The analysis of results of educational interaction via Telegram messenger is presented (112 students’ survey, evaluation of learning outcomes in experiment (112 students) and control (110 students) groups). The empirical research has shown that Telegram messenger allowed supporting the educational process in the conditions of unexpected and forced quarantine restrictions, with no loss of qualitative indicators, achieving the pedagogical goals.Стаття присвячена проблемі використання месенджера Telegram як засобу підтримки навчального процесі в умовах вимушених карантинних обмежень, зумовлених пандемією Covid-19. Проаналізовано сучасні месенджери(Telegram, Viber, Facebook Messenger, WhatsApp) за визначеними критеріями (комерційність, функціональність, архітектура, безпека) та показниками, означено переваги використання Telegram для підтримки навчального процесу. Характеризовано сутність, переваги та можливості використання Telegram Chatbot. Описано основні кроки для створення Telegram Chatbot. Надано рекомендації для покращення педагогічного ефекту використання Telegram Chatbot. Представлено аналіз результатів освітньої взаємодії з використанням месенджера Telegram (опитування студентів, оцінка результатів навчання експериментальної (112 студентів) та контрольної (110 студентів) груп. Емпіричне дослідження показало, що месенджер Telegram дозволив здійснити підтримку навчального процесу в умовах несподіваних та вимушених карантинних обмежень, без втрати якісних показників, із досягненням педагогічних цілей