bluuebunny/crossref_metadata_2025_split huggingface dataset:
Imprints of the Jittering Jets Explosion Mechanism in the Morphology of the Supernova Remnant SNR 0540-69.3
Authors: Soker Noam 
Published: January 2022

Abstract
I identify a point-symmetric structure in recently published VLT/MUSE velocity maps of different elements in a plane along the line of sight at the center of the supernova remnant SNR 0540-69.3, and argue that jittering jets that exploded this core collapse supernova shaped this point-symmetric structure. The four pairs of two opposite clumps that compose this point symmetric structure suggest that two to four pairs of jittering jets shaped the inner ejecta in this plane. In addition, intensity images of several spectral lines reveal a faint strip (the main jet-axis) that is part of this plane of jittering jets and its similarity to morphological features in a few other SNRs and in some planetary nebulae further suggests shaping by jets. My interpretation implies that in addition to instabilities, jets also mix elements in the ejecta of core collapse supernovae. Based on the point-symmetric structure and under the assumption that jittering jets exploded this supernova, I estimate the component of the neutron star natal kick velocity on the plane of the sky to be ≃ 235 km s−1, and at an angle of ≃47° to the direction of the main jet-axis. I analyze this natal kick direction together with 12 other SNRs in the frame of the jittering jets explosion mechanism.
Visual field inhomogeneous in brain–computer interfaces based on rapid serial visual presentation
Authors: Zhang Shangen , Chen Xiaogang , Wang Yijun , Liu Baolin , Gao Xiaorong 
Published: January 2022

Abstract

Objective. Visual attention is not homogeneous across the visual field, while how to mine the effective electroencephalogram (EEG) characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain–computer interface (BCI) are still distressing explorative scientists. Approach. Images were encoded into a rapid serial visual presentation (RSVP) paradigm, and were presented in three visuospatial patterns (central, left/right, upper/lower) at the stimulation frequencies of 10, 15 and 20 Hz. The comparisons among different visual fields were conducted in the dimensions of subjective behavioral and EEG characteristics. Furthermore, the effective features (e.g. steady-state visual evoked potential (SSVEP), N2-posterior-contralateral (N2pc) and P300) that sensitive to visual-field asymmetry were also explored. Main results. The visual fields had significant influences on the performance of RSVP target detection, in which the performance of central was better than that of peripheral visual field, the performance of horizontal meridian was better than that of vertical meridian, the performance of left visual field was better than that of right visual field, and the performance of upper visual field was better than that of lower visual field. Furthermore, stimuli of different visual fields had significant effects on the spatial distributions of EEG, in which N2pc and P300 showed left–right asymmetry in occipital and frontal regions, respectively. In addition, the evidences of SSVEP characteristics indicated that there was obvious overlap of visual fields on the horizontal meridian, but not on the vertical meridian. Significance. The conclusions of this study provide insights into the relationship between visual field inhomogeneous and EEG characteristics. In addition, this study has the potential to achieve precise positioning of the target’s spatial orientation in RSVP-BCIs.
Comparative analysis of air and water flows in simplified hydraulic turbine models
Authors: Skripkin S G , Suslov D A , Litvinov I V , Gorelikov E U , Tsoy M A , Shtork S I 
Published: January 2022

Abstract
This article presents a comparative analysis of flow characteristics behind a hydraulic turbine runner in air and water. Swirling flow with a precessing vortex core (PVC) was investigated using a laser Doppler anemometer and pressure pulsation sensors. The experiments were conducted on aerodynamic and hydrodynamic test rigs over a wide range of hydraulic turbine operating conditions. Part-load modes of hydraulic turbine operation were investigated using the Fourier transform of pressure pulsations obtained from acoustic sensors. The features of the swirling flow were shown for the range of operating conditions from deep partl-load to overload.
Practical application of natural convective heat exchange of electrical equipment with air
Authors: Gubanov S M 
Published: January 2022

Abstract
This paper provides the physical and mathematical model of the air flow in a volume, containing electrical equipment with the heat-generating and heat-absorbing surfaces. The model predicts the temperature fields and air flow velocities across the volume. Using the developed model, we calculate the values of heat fluxes in the vicinity of the thermostated electrical equipment for three different cases: natural convective, forced and mixed modes of the airflow. The possibility of beneficial use of natural convective air flows for the transfer of thermal energy is analyzed. The results are applied in an industrial enterprise. Energy consumption for ventilation is significantly reduced.
The percolation model of relative conductivities and phase permeabilities
Authors: Kolesnikov B P , Arushanyan R R 
Published: January 2022

Abstract
The universal mathematical model of relative conductivities of percolation clusters and phase permeabilities of oil-water-saturated rocks is presented. It is obtained on the basis of percolation theory, porous body physics and statistics. The model takes into account the influence of change in pore space surface properties and the nature of fluid flow on the studied characteristics and may be applied for comprehensive analysis and modeling of technological processes of oil production.
On thermal problems of the solar thermal multigeneration: new nanomaterials and working fluids
Authors: Dmitriev A S , Klimenko A V 
Published: January 2022

Abstract
The study considers various thermophysical problems, including the processes of heating new nanomaterials and nanofluids, as applied to solar thermal multigeneration (steam generation and turbine and turbineless conversion into electrical energy), as well as thermoelectric generation (solar thermoelectric generation) using new nanomaterials, including graphene and its composites. The main unsolved problems of thermohydrodynamics and heat transfer in such systems are noted.
Active thermal interface graphene nanocomposites for thermal control of electronic and power devices
Authors: Babenko D D , Dmitriev A S , Mikhailova I A 
Published: January 2022

Abstract
New experimental and calculated data are presented for active thermal interface materials, in which heat is removed not only due to high thermal conductivity, but also due to the evaporation of liquids, for example, water, inside a nanoporous graphene structure. It is shown that such active thermal interfaces may be new systems of active thermal control.
Problem of maintaining a normal condensate dissolved oxygen concentration
Authors: Vodeniktov A D , Chichirova N D 
Published: January 2022

Abstract
Study presents the results of the steam surface KCS-200-2 reconstruction. In order to maintain the dissolved oxygen concentration, according to the Code of Operation for Power Plants, the steam sparger was installed in condenser hotwell. Despite the abnormal air leakage level, reducing of dissolved oxygen concentration was reached. The dissolved oxygen concentration reduced, on average, by 2 times. As it was expected, in the cases of low inlet cooling water temperature, the final oxygen concentration did not reach the normal level. In last 3 tests the dissolved oxygen concentration was reduced to 19 mg /l. The results show a possibility of described reconstruction experience.
Multicomponent mixing on the “diffusion – convection” transition boundary at elevated pressures
Authors: Kossov V N , Fedorenko O V , Zhaneli M , Mukhatova K 
Published: January 2022

Abstract
An experimental and theoretical study of three-component mixing at the “diffusion – convection” boundary at elevated pressures is carried out. It is shown that the pressure dependence of the dimensionless parameter α, defined as the ratio of the experimental values of the component concentrations to those calculated by the Stefan-Maxwell equations, has characteristic regions due to the interaction of structural formations moving towards each other, in which a transition from one critical motion to another occurs. Within the framework of a linear analysis of the stability of a ternary gas mixture for a vertical circular cylinder channel, it is shown that scale perturbations determining the transition from one type of flow to another correspond to a certain value of the perturbation mode n and the critical Rayleigh numbers.
Experimental study of an internal combustion engine fueled by a low-calorific value producer gas
Authors: Nikitina G I , Kozlov A N , Penzik M V 
Published: January 2022

Abstract
This paper describes an experimental study of the operation of an internal combustion engine of fueled by a low-calorific value gas. The main operating parameters of low-power ICE were determined. Efficiency was also evaluated when the ICE was converted to operate on producer gas. In the experiment, it was shown that the engine reached a stable operating mode under load and data on the temperature and exhaust gases composition were obtained. According to our estimates, in the steady-state operation of the internal combustion engine with a load, the efficiency factor was about 22 %. When using the model gas, the from generator output power, was about 30-40 % of the nominal value, under variable load conditions. However, it was found that in steady-state operation, the power of the internal combustion engine was 40-55% of the nominal value.
Control of ship tank heating systems to increase their energy efficiency
Authors: Syraleva M N , Kudinovich I V 
Published: January 2022

Abstract
An important problem in the operation of icebreakers and Arctic ships is to prevent excessive icing of ballast tanks above the waterline. Uncontrolled ice formation can damage ballast systems and lead to malfunctions of ballast systems during cargo operations. This paper presents an analysis of the dynamics of water temperature in a ballast tank when the heating system is turned on and off. Recommendations on the control algorithm for the heating system that provides maximum energy efficiency are proposed.
Problems of acoustic safety in power engineering
Authors: Tupov V B , Taratorin A A , Skvortsov V S , Mukhametov A B 
Published: January 2022

Abstract
Environmental safety issues are becoming increasingly important in the life of society. Among environmental safety issues in power engineering, acoustic safety occupies a special place. The problem of acoustic safety is associated with the fact that the regular operation of power equipment leads to an increased noise level, and power facilities are located in close proximity to residential areas. In this work, acoustic calculations were performed to determine the sanitary protection zone for gas turbines units (GTU) and combined cycle gas turbine units (CCGT) of various capacities. A formula was obtained for calculating the width of the sanitary protection zone depending on the capacity of gas turbine units and combined cycle plants and their number. It is shown that the sanitary protection zone (SPZ) of a power unit of high capacity is smaller than the sanitary protection zone of several power units of the same capacity. It is found that the noise levels from individual groups of equipment can determine the noise level at the entire border of the sanitary protection zone or in its individual sections. At the same time, noise suppression measures should be taken for all sources that generate noise levels in excess of standards. It is necessary to start noise suppression measures from those sources that generate excess noise in a larger section of the sanitary protection zone.
Properties of anhydrous hydrogen fluoride in the temperature range from 140 K to 190 K
Authors: Gubanov S M 
Published: January 2022

Abstract
This paper presents the analysis of the known empirical formulas on the pressure of the saturated vapors of hydrogen fluoride depending on the temperature. The possibility of using the formulas to determine the vapor pressure under the low temperatures is assessed. The calculation error of the pressure value depending on temperature outside the interval are determined.
The investigation of the average diameter of the SiO2 nanoparticles effect on the oil displacing efficiency from the pore in the rock formation using nanosuspension as a displacing agent
Authors: Lobasov A S , Minakov A V 
Published: January 2022

Abstract
The numerical investigation of the nanofluid flow, which displaced the oil, in a microchannel was carried out. The effect of the average diameter of the SiO2 nanoparticles on the oil displacing efficiency by nanofluids for different sizes of microchannel at various Reynolds numbers was studied. A T-shaped microchannel with a vertical channel, called a pore channel, which imitated the pore in the rock formation was considered as a computational domain. The main flow channel width and height were 200 µm. The width and height of the pore channel were varied in the range from 100 µm to 800 µm. The Reynolds number varied from 0.1 to 100. The oil recovery coefficient, which is defined as the ratio of the displacing volume of oil from the pore to the volume of the pore was considered as the main studied characteristic. The nanofluid is considered a single-phase fluid with experimentally obtained properties. The mass concentration of SiO2 nanoparticles was 0.5%. The average diameters of nanoparticles were 5 nm, 18 nm, and 50 nm. It was found, that the oil recovery coefficient increased with a decrease in the average diameter of nanoparticles. It was obtained that the nanofluid can enhance the oil recovery several times compared to pure water.
Mathematical modelling of thermal microexplosion in a catalyst granule with point sources of heat release
Authors: Derevich I V , Fokina A Yu 
Published: January 2022

Abstract
A mathematical model of heat and mass transfer in a spherical catalyst granule is proposed. Exothermic synthesis reactions are carried out on point active centres located inside a porous ceramic granule. From the surface of the granule the heat of catalytic reactions is removed into liquid synthesis products. The rate of a chemical reaction is modelled by a modified Arrhenius law. In contrast to the homogeneous model of a catalytic granule methods for calculating heat transfer processes in a system of point, active centres do not develop. An iterative procedure is suggested to calculate the unknown temperature and concentration of the reagent at the active centre. It is shown that the temperature of the active centres is significantly higher than in the volume of the granule. The results of modelling a thermal explosion with increasing granule size and reactor temperature are presented.
Investigating the characteristics of the development of the boundary layer motion of locally nonequilibrium systems
Authors: Popov V I , Kuznetsov A V 
Published: January 2022

Abstract
The method of integral momentum transfer relations has been extended to polymer systems with a locally nonequilibrium relaxation microstructure. The influence of the locally non-equilibrium transfer of the impulse flux on the characteristics of the development of their boundary-layer motion is analyzed.
Experimental studies of the formation of zones resulted from air flow around a system of model buildings
Authors: Meshkova V D , Dekterev A A , Dekterev D A , Lobasov A S 
Published: January 2022

Abstract
This paper presents the results of working out the methodology for conducting experimental studies of the flow around the objects modeling the urban environmental conditions. The experiments were conducted in the wind tunnel of the Siberian Federal University. Two objects of different heights imitating buildings were considered the models. Special attention was paid to the study of the flow pattern at the tandem arrangement of model buildings. Visualizing the flow, the low-velocity and high-velocity zones, as well as recirculation areas were identified. At that, these zones had their peculiarities in terms of the direction of flow twisting behind each object. The study allowed revealing that the vortices separating from the edges of the studied objects play a special role in the flow formation.
Features of the educational program «Nanotechnologies and nanomaterials in energy»: machine learning
Authors: Babenko D. D. , Dmitriev A. S. , Makarov P.G. , Mikhailova I.A. 
Published: January 2022

Abstract
The results of the development of new educational programs in the field of nanotechnology and nanomaterials in the energy sector, which have been developed and are actively used by the National Research University “MPEI”, are presented. Modern nanomaterials and nanotechnological processes in traditional and alternative (“green”) energy require new approaches, including statistical methods for the analysis and synthesis of experimental data and design options. For this reason, without the active use of machine learning methods, it is impossible to train qualified specialists in the field of promising energy problems and their solutions. Through teaching, research, and innovation, «MPEI» exceptional community pursues its mission of service to the nation and the world.
Long-term Variation of Absorption and Total Aerosol Optical Properties over Typical Provinces of China from Satellite Observations
Authors: Li Heng 
Published: January 2022

AbstractIncrease of atmospheric aerosols has a profound impact on the Earth’s climate. It’s also one of the crucial factors that cuasesd more fequent air pollution events in China. Monthly average Aerosol Optical Depth (AOD) from MODIS and UltraViolet Absorbing aerosol Index (UVAI) from OMI during 2011 to 2019 are used to analyse the trend of absorption and total aerosol optical properties over three typical provinces of China, namely Shandong, Gansu and Guangdong provinces. The results show the average annual AOD of the three provinces are all decreasing while UVAI rises during this period. In addition, the monthly variation of AOD and UVAI are also obviously different over these provinces. In particular, the peak value of AOD appeared in July and the trough appeared in December over Shandong Province. And the peak appeared in April over Gansu Province, but AOD decrease slower then over Shandong Province. And there were two peaks in April and August over Guangdong Province. For UVAI, the peaks over Shandong and Gansu provinces both occur in January, while that over Guangdong Province appears in March. Above mentioned differences in the long-term trend and monthly variation of AOD and UVAI might be closely related to the meteorological conditions and aerosol emission of these three provinces.
Preparation and the Catalytic Properties of Attapulgite / TiO2 Nanocomposites
Authors: Shang Jianping , Li Tao , Qin Xiaoping , Zhao Bin , Li Xuefei 
Published: January 2022

Abstract
With the rapid development of industry, the discharge of textile printing and dyeing wastewater will cause serious pollution to other pure water bodies. It is imperative to deal with textile printing and dyeing wastewater. In this paper, with titanium tetrachloride as a precursor, attapulgite (ATP) / TiO2 nanocomposites were prepared by a neutralizing hydrolysis method and their catalytic activities were investigated by the oxidative degradation of methylene blue dye using ozone as oxidant. The test results showed that there were significant interactions between TiO2 and ATP support. The effects were also studied of ozone concentration, catalyst amount, reaction temperature, and initial concentration of methylene blue on the degradation rate of methylene blue catalyzed by the prepared attapulgite / TiO2 nanocomposites, and under the optimal conditions, the methylene blue could be degraded more than 90% in 30 minutes. Compared with that of pure ATP, the catalytic activities of ATP / TiO2 nanocomposites were enhenced remarkably. The degradation mechanism of methylene blue was also discussed.
Wastewater Treatment by Enhanced H2O2 – Based Advanced Oxidation Process (AOP) Methods: A Review
Authors: Wu Qitong 
Published: January 2022

Abstract
The development of industries leads to large amount of organic wastewater that contains phenol and dyes. For the treatment of these pollutants, the applications of H2O2 based – AOP have advantages in less pollution, low costs and high efficiency. In order to promote the degradation effect of H2O2, researchers used several methods to strengthen the effect of H2O2 based – AOP. This article mainly reviews the development of catalysts of the strengthened Catalytic Wet Hydrogen Peroxide Oxidation (CWPO), Fenton-like and other assistant-H2O2 systems in the degradation of phenol and dyes recent years. Challenges and development directions concerning catalysts in the future are discussed.
Verification Analysis of the Relationship Between Soil Pressure and Displacement of Retaining Structure
Authors: Chen Jinyong , Li Zhongchao , Liang Rongzhu , Jiang Guosheng , Wu Wenbing 
Published: January 2022

Abstract
Variation laws of earth pressure accounting for the displacement of are taining wall can be well described by mathmatical fitting in the study of the relationship between earth pressure and retaining wall displacement. The common mathematical function expressions of earth pressure displacement of retaining wall can be divided into sinusoidal function model, exponential like function model, hyperbolic function model, fitting function and semi-numerical and semi-analytical model function, etc. The characteristics and shortcomings of the current expression of earth pressure displacement function are summarized. Then combined with the field test and model test, the applicability and characteristics of various mathematical functions in predicting the displacement of earth pressure with retaining structures are analyzed. The results show that when the displacement is small, the sinusoidal function model and the quasi-exponential function model are close to the measured results. When the displacement of retaining structure is large, the fitting results of hyperbolic model and semi-numerical and semi-analytical model are better. For the prediction of earth pressure displacement relationship in passive area, the buried depth has a great influence. And the error between the theoretical value and the actual value has a great influence on the fitting result of the model.