A search for hyperluminous X-ray sources in the XMM-Newton source catalog

We present a new method to identify luminous off-nuclear X-ray sources in the outskirts of galaxies from large public redshift surveys, distinguishing them from foreground and background interlopers. Using the 3XMM-DR5 catalog of X-ray sources and the SDSS DR12 spectroscopic sample of galaxies, with the help of this off-nuclear cross-matching technique, we selected 98 sources with inferred X-ray luminosities in the range $10^{41} < L_{\rm X} < 10^{44}\,{\rm erg\,s}^{-1}$, compatible with hyperluminous X-ray objects (HLX). To validate the method, we verify that it allowed us to recover known HLX candidates such as ESO 243$-$49 HLX$-$1 and M82 X$-$1. From a statistical study, we conservatively estimate that up to $71 \pm 11$ of these sources may be fore- or background sources, statistically leaving at least 16 that are likely to be HLXs, thus providing support for the existence of the HLX population. We identify two good HLX candidates and using other publicly available datasets, in particular the VLA FIRST in radio, UKIDSS in the near-infrared, GALEX in the ultra-violet and CFHT Megacam archive in the optical, we present evidence that these objects are unlikely to be foreground or background X-ray objects of conventional types, e.g. active galactic nuclei, BL Lac objects, Galactic X-ray binaries or nearby stars. However, additional dedicated X-ray and optical observations are needed to confirm their association with the assumed host galaxies and thus secure their HLX classification.Comment: 20 pages, 6 figures, accepted to Ap

Machine learning in reservoir permeability prediction and modelling of fluid flow in porous media

Reliable data on the properties of the porous medium are necessary for the correct description of the process of displacing hydrocarbons from the reservoirs and forecasting reservoir performance. The true permeability of the reservoir is one of the most important parameters which determination is time-consuming, costly and require skilled labor. The paper describes the methodology for determining the permeability of a porous medium, based on machine learning. The results of laboratory experiments, available in the database (terrigenous reservoirs with permeability in the range from 12 to 1132 md), are used to train the neural network, and then to predict the reservoir permeability. Comparison of the predicted and calculated permeability values showed a fairly good match between them with the determination coefficient of 0.92. The last task considered in this paper is to obtain an analytical expression describing a fluid flow in a porous medium using machine learning. This procedure enabled to obtain a resultant equation of fluid flow in a wide range of reservoir parameters and pressure gradients, which can be used in reservoir simulators.publishedVersio

Feed-Forward and Feed-Back Circuits of the NRF2/AP-1 Composite Pathway

Being the central regulator of oxidative status of the cell, NRF2 must be regulated so that its activity can be rapidly and strongly induced when needed and quickly suppressed when not. Moreover, for the cell, NRF2 means much more than just antioxidant defense. Numerous general functions rely on NRF2 and related factors. All this implies that the NRF2 pathway has peculiar and powerful mechanisms of control of its activity. To a great extent, these mechanisms are based on feed-forward and feed-back circuits. These circuits, more than a dozen, are in the focus of this chapter

Optical Camera with high temporal resolution to search for transients in the wide field

The wide field optical camera with high temporal resolution for the continuous monitoring of the sky in order to catch the initial stages of GRBs is described.Comment: 4 pages, 4 figures. To be published in "Il Nuovo Cimento", Proceedings of the 4th Rome Workshop on Gamma-Ray Bursts in the Afterglow Era, eds. L. Piro, L. Amati, S. Covino, B. Gendr

Public Media as SMM and Community Playground

The article explores the types of public media in social networks and strategy of publications, gives an idea about the public media as SMM and community site and conclusions about the prospects for the use of the public media.В статье исследуются типы пабликов медиа в социальных сетях, стратегии пабликостроительства. Дается представление о паблике как об SMM и комьюнити-площадке, делаются выводы о перспективах использования пабликов

A description of a system of programs for mathematically processing on unified series (YeS) computers photographic images of the Earth taken from spacecraft

A description of a batch of programs for the YeS-1040 computer combined into an automated system for processing photo (and video) images of the Earth's surface, taken from spacecraft, is presented. Individual programs with the detailed discussion of the algorithmic and programmatic facilities needed by the user are presented. The basic principles for assembling the system, and the control programs are included. The exchange format within whose framework the cataloging of any programs recommended for the system of processing will be activated in the future is displayed

An Analysis of the Chemical Composition of the Atmosphere of Venus on an AMS of the Venera-12 Using a Gas Chromatograph

Eight analyses of the atmosphere of Venus were made beginning at an altitude of 42 km right down to the surface of the planet. The following were detected in the atmosphere of Venus: nitrogen in concentrations of 2.5 plus or minus 0.5 volumetric %, argon ir concentrations (4 plus or minus 2) x 10 to the minus 3 power volumetric %, CO--(2.8 plus or minus 1.4) x 10 to the minus 3 power volumetric % and SO2 in concentrations (1.3 plus or minus 0.6) x 10 to the minus 2 power volumetric %. The upper limits were estimated for the content of oxygen and water equal to 2 x 10 to the minus 3 power and 10 to the minus 2 power volumetric %, respectively

Application of laser interferometry to analyze cutting tool state during machining

The efficiency of a cutting tool can be enhanced through stress-strain and temperature studies. Existing mathematical methods implement simplified boundary conditions, and experimental methods that are either inapplicable to real working conditions or lack the necessary accuracy. This study aims to develop novel experimental methods for stress-strain and temperature field analyses. The approaches entail recording the side deformation fields of the cutting tool by laser interferometry during its operation, separating the deformation fields caused by the cutting forces and heating, as well as calculating the stress-strain and temperature fields using the Young's modulus, Poisson's ratio, and coefficient of linear thermal expansion of the tool material. The advantages of these methods include their applicability under real cutting conditions and the possibility to study the stress-strain and temperature fields of a tool during non-stationary operation by high-speed video recording. The study proves the efficiency of the proposed methods by the orthogonal machining of difficult-to-cut steel disc using a cemented carbide tool with positive rake angle. As a result, the temperature and principal stress fields in the tool were determined. Developed methods can help in the study of cutting tool efficiency. © Published under licence by IOP Publishing Ltd

Features of Industrial and Environmental Risk Management in Order to Ensure Sustainable Development of the Enterprise

В настоящее время число предприятий по добычи и переработки нефти и газа целью которых является не только достижение высоких производственных показателей, но и разработка подходов к уменьшению степени тяжести экологических и промышленных рисков, неуклонно растет. Эти задачи решаются путем создания корпоративных стандартов и регламентов. Оценка степени рисков служит важнейшим инструментом таких стандартов. Промышленные и экологические риски имеют высокую степень влияния на деятельность компании, и зачастую отечественные предприятия нефтегазовой отрасли делают акцент именно на эти риски.At present, the number of oil and gas production and processing enterprises whose goal is not only to achieve high production indicators, but also to develop approaches to reducing the severity of environmental and industrial risks is steadily growing. These tasks are solved by creating corporate standards and regulations. Risk assessment is an essential tool for such standards. Industrial and environmental risks have a high degree of influence on the company’s activities, and often domestic oil and gas companies focus on these risks