bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of superficial gas velocity on heat transfer in a two-phase system with additive heater surfaces
Authors: Eloyan K S , Ronshin F V , Litvintceva A A , Cheverda V V 
Published: December 2020

Abstract
The problem of removing high heat fluxes from a powerful microelectronic element (chip, microprocessor) is one of the most difficult tasks. One of the promising methods for cooling is the use of two-phase systems in a minichannel with a stratified flow regime. Additive technologies allowing the creation of structured surfaces are of increasing interest. The study of heat transfer using structures on the surface in the form of cylindrical protrusions in comparison with a smooth surface with characteristic size (diameter and height) equal to 300 μm is presented in this work.
Kinetic and thermophysical phenomena in the synthesis of porous composites from (Ti+Si) and (Ti+Al+Si) powder mixtures in the reaction sintering mode
Authors: Knyazeva A G , Korosteleva E N 
Published: December 2020

Abstract
Theoretical and experimental study of the synthesis of porous composites from powder mixtures for Ti-Si and Ti-Al-Si systems in the reaction sintering mode is carried out in the present work. The thermokinetic model of reaction sintering is formulated taking into account competing physicochemical stages. The model includes the heat balance equation, the kinetic equations for the components involved in the reactions, the kinetic equation for porosity changing during heating, reaction sintering, and cooling. The melting is assumed to occur within the temperature range of liquidity and solidus. These processes lead to the appearance of local stresses and volumetric changes. The results of experimental studies show good agreement with the numerical calculations.
Numerical simulation of heat transfer in a large room with a working gas infrared emitter
Authors: Borisov B V , Kuznetsov G V , Maksimov V I , Nagornova T A , Gutareva N Y 
Published: December 2020

Abstract
The article presents a new approach to determining the main characteristics of the thermal regime in the buildings and structures heated by the gas infrared emitters, based on the analysis of convective heat transfer in the air and thermal conductivity in the enclosing structures. The authors have considered a mathematical model of turbulent heat transfer in the framework of the standard k-e model under radiant heating conditions. The simulation was carried out for a large room with an approximation to the real operating conditions of an industrial facility. The options for heating an empty room and the room with an object were considered.
Experience in DNS of turbulent free convection in air along an isothermal vertical plate
Authors: Smirnov E M , Levchenya A M , Ivanov N G , Smirnovsky A A , Smirnov P E 
Published: December 2020

Abstract
The paper presents results of direct numerical simulation of the turbulent free convection boundary layer developing along a vertical heated plate up to the local Grashof numbers, Grx, of 8.1010 (Pr=0.7). A span-distributed macro-roughness of a selected form is used for enhancing transition to turbulence, so that the Grx–value corresponding to the end point of transition would be close to that reported for the case of natural transition. The results obtained for the first-and the second-order turbulent flow and heat transfer statistics in the developed turbulent regime are in a good accordance with the experimental data reported by Tsuji and Nagano (1988).
Cylinder diameter measurement with displacement and rotation error correction for non-telecentric optics
Authors: Rakhmanov V V , Dvoynishnikov S V , Semenov D O , Glavny V G 
Published: December 2020

Abstract
The paper presents the implementation of a method for measuring the diameter of cylinders in traffic along a transport line using machine vision systems with correction of the error of displacement and rotation of the product for the case of using non-telecentric optics. Diameters were measured for a set of displacements and rotations of the cylinder, and estimates of the achievable errors of this implementation of the layout of the measuring installation were made.
Hydrogen diffusion in AB5 type metal hydride anodes by potentiostatic intermittent titration technique
Authors: Kazakov A N , Bodikov V.Yu. , Blinov D.V. , Volodin A.A. 
Published: December 2020

Abstract
Metal hydrides are widely used for hydrogen-related energy storage applications due to their high volumetric capacity, safety, and selectivity to absorb hydrogen. One of the main applications of metal hydrides is their use as electrode material in Ni-MH batteries. Metal hydride electrodes provide high energy density, high rate capability, tolerance to overcharge and over-discharge, and no electrolyte consumption during the charge/discharge cycle. One of the key factors of metal hydride electrode performance is a hydrogen diffusion from the electrolyte to the bulk of metal hydride material. In the present study, effective hydrogen diffusion coefficients in AB5 type metal hydride electrodes during the charging process are investigated employing potentiostatic intermitent titration technique.
Heating of a carbon nanotubes array with few-cycle optical pulses
Authors: Konobeeva N N , Belonenko M B 
Published: December 2020

Abstract
In this paper, we investigate the heating of carbon nanotubes under the action of few-cycle optical pulses. Within the framework of the hot electron model, an array of carbon nanotubes which is irradiated by an electromagnetic wave with a high emission intensity is considered. The time-dependence of the generated heat is analyzed for various system parameters (duration of the few-cycle laser pulse and relaxation time of the electrons in carbon nanotubes).
Studying dielectric properties of oil shale
Authors: Zinnatullin R R , Sultanguzhin R F 
Published: December 2020

Abstract
The paper describes the methodology, equipment and results of studying the features of dielectric properties of oil shale in the frequency range for values from values 0.05 to 300 MHz and temperatures for values from 20 to 200°C. It is shown that the dielectric parameters for the studied shale samples are an order of magnitude higher than for terrigenous rocks, and along the layers they are about 1.5 - 4 times higher than across the layers. The dielectric properties of the studied shale are found to undergo dispersion in the range for values from 50 to 125 MHz and have nonlinear temperature dependence.
Simulations of partial discharges in a chain of gas cavities at AC voltage
Authors: Kupershtokh A L , Lazebnyi D B 
Published: December 2020

Abstract
The stochastic model of partial discharges (PDs) in chains of gas caverns in condensed dielectrics is improved. The equations for electric field potential are solved in a region filled by dielectric containing gas caverns. The opportunity of a “relay-race” propagation of PDs in a linear chain of gas caverns under constant and ramp voltage was shown in previous studies. This mechanism is possible if the interval between caverns is relatively small. In this case, the wave of PDs can travel along the chain. This paper is devoted to modelling “relay-race” waves in a zigzag chain of gas-filled caverns under AC voltage.
Formation of periodic surface structures in multilayer amorphous Ge2Sb2Te5 thin films irradiated by femtosecond laser pulses
Authors: Kolchin A V , Shuleiko D V , Zabotnov S V , Golovan L A , Presnov D E , Kaminskaya T P , Lazarenko P I , Kozyukhin S A , Kashkarov P K 
Published: December 2020

Abstract
Phase transitions and periodic surface modification in amorphous Ge2Sb2Te5 thin films on multilayer substrate were revealed as a result of the samples irradiation by femtosecond laser pulses with the wavelength of 1250 nm. Raman spectroscopy revealed partial crystallization in the treated samples. Calculations and analysis of scanning electron and atomic-force microscopy data showed that formation of the periodic surface structures is related to photoinduced surface plasmon-polariton excitation and depends on laser radiation fluence. The obtained results are useful for design and fabrication of new promising data-storage and polarization optics devices.
Numerical simulation of adiabatic shear bands formation processes on two-dimensional eulerian meshes
Authors: Muratov R V , Kudryashov N A , Ryabov P N 
Published: December 2020

AbstractIn this work we suggest a mathematical model of motion of the elasto-plastic materials with nonlinear plasticity constitutive law; we also propose an effective numerical method for numerical simulations of such tasks on two-dimensional eulerian meshes. Based on the method, we research formation of multiple adiabatic shear bands (ASB) at high-speed shear deformations. We test our approach on two-dimensional problem where the initial heterogeneity of temperature leads to formation of adiabatic shear band.
REQUIREMENTS FOR THE DUAL Fe + H/He BEAM AT THE ACCELERATOR HIPR FOR SIMULATION OF NEUTRON INFLUENCE ON NUCLEAR REACTOR MATERIALS
Authors: Fedin P A , Ziiatdinova A V , Pryanishnikov K E , Kuibeda R P , Kulevoy T V , Nikitin A A , Rogozhkin S V 
Published: December 2020

Abstract
Ion accelerator facility is a powerful tool that can be used to simulate neutron irradiation effects in reactor materials. At the NRC “Kurchatov Institute” - ITEP the heavy-ion accelerator HIPr is used for the ion-beam simulation of radiation damage in steels and alloys. Irradiation is provided with the wide range of metal ions (mainly Fe2+). It is essential to include helium and hydrogen beams for the proper simulation of transmutation driven mechanisms of swelling and void formation. Energies, beam line angle and intensity are determined for design of the second beam line for He/H implantation at HIPr.
Simulation of the isothermal and Hugoniot characteristics of organic compounds via the reactive molecular dynamics
Authors: Kozlova S A , Gubin S A , Maklashova I V 
Published: December 2020

Abstract
This article provides the results of reactive molecular dynamics simulation of shock loading of cyclic hydrocarbon C6H6 and isotherm curve of energy-intensive nitramine C4H8N8O8. To describe the interatomic interaction, as well as to analyze the kinetics of decomposition, we used two parameterizations of the reactive force field ReaxFF. In this paper, we compared the capabilities of ReaxFF force fields to describe the kinetics of the decomposition of benzene behind the front of a shock wave and the ability to reproduce phase transformations of carbon under conditions of high pressures and temperatures. The results obtained are in good agreement with the experiment.
Characteristic for long GRBs with high energy component presence, which not required cosmological corrections
Authors: Arkhangelskaja I V 
Published: December 2020

Abstract
Several thousands of gamma-ray bursts were observed by various experiments. During several GRBs very high-energy photons were detected both in space and ground-based experiments (up to some tens of GeV and up to some TeV, respectively). Usually 2 classes of bursts are considered: short and long GRBs separated by t90~2s. Because of several hundreds of GRBs located at high redshift, its sources’ origins nature concluding as cosmological. Therefore correction to cosmological dilation of GRBs t90 should be considered during any analysis of bursts duration. Firstly very high-energy component was observed during GRB 970417a: 18 photons with energy ~650 GeV were registered by Milagrito within t90 interval of this burst. Now several tens of GRBs reveal activity in energy bands up to some tens of GeV and up to some TeV accordingly data of space and ground-based experiments correspondingly. Unfortunately redshift is unknown approximately for half of GRBs with high energy component presence. Here we introduce new parameter Rt is ratio of maximum energy photon arrival time to burst duration and it not required cosmological correction. At least 2 groups of long GRBs could be separated using parameter Rt: for 25% events highest energy gammas detected within t
90 interval, but for other 75% of bursts it registered more than 10 sec. later than one. Moreover, preliminary results of analysis allow concluding 2 subtypes of second group GRBs. For one μ-quantum with maximum energy arrived within t90. For other such photon was registered later than t90. Therefore, the results of preliminary analyses allow conclude long GRBs population inhomogeneity.
The results of analysis of Rich Galaxy Clusters from CfA2 Redshift Survey spatial distribution
Authors: Arkhangelskaja I V , Khanh L N , Galper A M , Dorosheva D N 
Published: December 2020

Abstract
Preliminary results of the investigation of the properties of 7 galaxy cluster from CfA2 redshift survey are discussed in the presented article. Clusters 933, 142, 1046, and 1652 have several peculiarities of the spatial distributions of galaxies. The distributions on absolute magnitude and luminosity represent two areas for clusters 933, 88, 142, 1046, 1101. The investigation of the spatial distribution and other characteristics of 88, 1101, 1046, 142, 933, 1242 and 1652 galaxy clusters allow concluding gravitational lensing effect. Galaxies from these areas are paired accordingly its spectral characteristics and position. Redshifts of these clusters are in the region 0.002 – 0.022. Preliminary results of analysis allow us concluding compact objects or dark matter blobs as lenses. Moreover, groups #933, #142, #1046 and #1652 reveals high-energy γ-associations on Fermi/LAT 10-Year Point Source Catalog 4FGL-DR2 (4FGL J1144.9 + 1937, 4FGL J0152.2 + 3714, 4FGL J1230.8 + 1223 and 4FGL J1653.8 + 3945); and sources 4FGL J0123.1+3421, 4FGL J1259.5+2332, 4FGL J1353.2+3740 are located inside sizes of clusters #88, #1101 and #1242. Also several anomalies of spatial dynamic of galaxies in these clusters were separated. Joint observations of such clusters by orbital gamma-ray observatories with high angular resolution and ground-based Cherenkov air-shower experiments could possibly clarify the type of gravitational lensing and processes of particle acceleration in these objects especially highest energy of emitted gammas. Thus we propose including these and similar clusters in the programs of observations of the planned experiment GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) with angular resolution ~0.01° at Eγ = 100 GeV. Also now it is discussed coordination of multiwavelength observations program of Cherenkov Telescope Array (CTA) and GAMMA-400 objects list for observations. Moreover, common observations of such clusters by orbital gamma-ray telescopes with high angular resolution and ground-based Cherenkov air-shower experiments could possibly clarify the type of gravitational lenses.
Analysis of the 28Si(α,α)28Si elastic scattering at energies from 12.7 to 50.5 MeV
Authors: Amer Ahmed Hammad , Penionzhkevich Yu. E. , Yergaliuly G. 
Published: December 2020

Abstract
The available experimental elastic scattering angular distributions data of α-particles on 28Si nucleus have been reanalyzed in the energy range from 12.7 to 50.5 MeV. The analysis performed within the context of optical model (OM) potential. In the framework of double-folding model (DFM), we created the real part of optical potential using a density dependent version BDM3Y1-Paris interaction model.
Improving the Precision of Calibrating a Large Low-background Proportional Counter
Authors: Petrenko O D , Gangapshev A M , Gavrilyuk Yu M , Kazalov V V , Kuzminov V V , Panasenko S I , Ratkevich S S , Tekueva D A 
Published: December 2020

Abstract
The study of low-yield effects requires not only good quality of the original data but also puts high requirements for their processing procedures to increase the efficiency of the selection of useful events. The exploiting of the large cylindrical proportional counter’s electrostatic topology allows improving the extrapolation of information about the primary ionization of a multipoint event. Long-term calibration measurements with an external 109Cd-source allowed the development of a new method for analyzing the pulse shape from a sizeable proportional counter. Optimized analysis of the current’s pulse shape from the electron cloud of primary ionization in the counter improved the resolution and energy calibration. As a result, the efficiency of selecting useful events was increased by 25%.
Review of two-phase emission detectors R&D (Dedicated to the memory of Prof. Boris A. Dolgoshein)
Authors: Bolozdynya A I 
Published: December 2020

Abstract
This review is dedicated to the 90th anniversary of the outstanding experimental physicist Boris Anatolyevich Dolgoshein, in whose laboratory exactly 50 years ago the first two-phase emission detector has been created. Today two-phase emission detectors found the best application in the most sensitive at the moment experiments searching for cold dark matter in the form of weakly interacting massive particles (WIMPs). Multi-ton active mass WIMP detectors of the upcoming G3 generation shall become sensitive to solar neutrinos interactions, to double-beta decay of isotopes containing in the working media with naturally occurring isotope abundances. The RED-100 detector constructed at NRNU MEPhI will be used for investigation of the reactor neutrino elastic coherent scattering off xenon nuclei at the Kalinin NPP in 2021. ProtoDUNE-DP prototype emission detector (6x6x6 m3 300 tons LAr) is currently being assembled at the CERN Neutrino Platform in support of the DUNE project focused on investigation of high energy neutrino oscillations. Thus the detector technology invented at MEPhI 50 years has demonstrated a great potential to be used in a variety of fundamental research programs.
Separation of signals from neutrons and gamma quanta by the method of normalized signals
Authors: Kirsanov M A , Klimanov S G , Nazarov I V , Chepurnov A S , Kubankin A S 
Published: December 2020

Abstract
The solution of the problem how to register fast neutrons in the presence of intense gamma radiation is required when solving such fundamental and applied problems as registration of the neutron and gamma background in underground low-background experiments (the low background detectors of the neutrino and dark matter); beam diagnostic at particle accelerators; radiation monitoring at nuclear facilities, nuclear medicine; environmental monitoring. To separate signals from neutrons and gamma quanta, scintillation detectors with organic scintillators are used. The best scintillators are organic crystals of stilbene and p-terphenyl. The efficiency of separating signals from neutrons and gamma quanta can be increased using various methods of digital signal processing of the pulse shapes of the registered signals. A parameter traditionally called the Figure of Merit (FOM) is used to compare these methods. The experimental setup consisted of a Pu-Be neutron source, a scintillation detector with organic crystal p-terphenyl, a Hamamatsu R6094 photomultiplier, a CAEN DT5730 Digitizer (500 MHz, 14bit), which store the shape of each pulse for the following digital processing. A new “method of normalized signals” was developed. Three variants of the new method of normalized signals are described, which give the following FOM values: 1.6, 1.7, and 2.1. The traditional method of signals separation on the same array of experimental data showed the efficiency FOM = 1.6. The new method of signal separation is used to register fast neutrons in the installation dedicated for the development of a compact neutron generator, which is necessary for the calibration of low-background detectors of neutrinos and dark matter particles.
Quality control of MPD electromagnetic calorimeter modules
Authors: Durum A , Britvich G , Denisov A , Chernichenko S , Kostin M , Sukhikh A , Yanovich A , Krechetov Yu , Semenov A Yu , Vlasov N 
Published: December 2020

Abstract
The Multi-Purpose Detector (MPD) is constructing to study the properties of the hot and dense matter created in heavy-ion collisions in the energy range of 4-11 A*GeV where the maximum baryonic density is expected. The crucial detector in the new experimental setup is a large-sized barrel electromagnetic calorimeter (ECal), designed for precise spatial and energy measurements for photons and electrons. Taking into account the requirements of high energy resolution, dense active medium with the small Moliere radius, and high segmentation of ECal, the Shashlyk-type electromagnetic calorimeter with projective geometry has been selected. The mass production of ECal modules has been started. In this talk, we report about methods and technologies for the quality control of ECal modules and their components.
Feasibility studies for the measurement of single-spin asymmetry in inclusive K0
s production at pion beam at U-70
Authors: Kalugin N K , Mochalov V V , Moiseev V V , Morozov D A , Nurusheva M B , Rykov V L , Semenov P A , Vasiliev A N 
Published: December 2020

Abstract
In the Spring 2018, the first physics data was accumulated in the new SPASCHARM experiment at U-70 accelerator of IHEP, Protvino. The first stage of SPASCHARM’s physics programs prursues the goal of studying spin effects in the beam fragmentation region at an unpolarized negative 28 GeV beam, interacting with a frozen polarized proton target. In this resport, the feasibility of measuring the single spin asymmetry AN
in the reaction: π
− + p↑→K
0

S
+ X is evaluated by Monte-Carlo simulations. We present estimates of the detection efficiency as well as for expected event statistics. It is shown that, in the process of interest above, the attainable statistical errors for AN
would be at the scale of a few percents.
Kaons and Antikaons in Multi-Phase Transport Model
Authors: Chahal Nisha , Dutt Suneel , Kumar Arvind 
Published: December 2020

Abstract
We investigate the impact of medium modifications of kaons and antikaons on there rapidity distribution and production ratio using A Multi-Phase transport (AMPT) model. The medium modified masses of kaons and antikaons, which are used as input in AMPT model, are calculated using the chiral SU(3) mean field model. Usually in chiral SU(3) models along with the Weinberg Tomozawa term, the contribution of explicit symmetry breaking term and three range terms are considered to evaluate in-medium masses of kaons and antikaons. In the present work, we have considerd Weinberg Tomozawa term and two range terms to study their impact on the above listed experimental observables. The repulsive contribution to the mass of K
+ meson from the Weinberg term dominates over the attractive contribution from two range terms. For the K
− meson Weinberg term as well as two range terms give attractive contribution. Considering all these features from chiral effective model on properties of K
+ and K
− mesons, we explore the rapidity distributions of kaons and antikaons.
Energy levels of three particle muonic ions (μeLi), (μeBe), (μeB)
Authors: Eskin A V , Korobov V I , Martynenko A P , Sorokin V V 
Published: December 2020

Abstract
We calculate the electron Lamb shift (2P-2S) and the electron energy interval (2S-1S) in muonic Coulomb three particle systems (μeLi), (μeBe), (μeB) on the basis of variational method. Basic relativistic corrections, corrections to the vacuum polarization and nuclear structure are taken into account by the perturbation theory. The obtained numerical results can be used for a comparison with future experimental data.