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Consideration of the influence of supports in modeling the electromagnetic fields of 25 kV traction networks under emergency conditions

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Global Energy Interconnection 2024年第4期7卷 528-540页

作者： Konstantin Suslov andrey Kryukov Ekaterina Voronina Pavel Ilyushin Department of Hydropower and Renewable Energy National Research UniversityMoscow Power Engineering InstituteMoscow 11250Russia Department of Power Supply and Electrical Engineering Irkutsk National Research Technical UniversityIrkutsk 664074Russia Department of Transport Electric Power Irkutsk State Transport UniversityIrkutsk 664074Russia Department of Research on the Relationship between Energy and the Economy Energy Research Institute of the Russian Academy of SciencesMoscow 117186Russia

Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of *** most intense magnetic fields occur when short circuits exist between the contact wire and rails or *** the short duration of exposure,they can adversely affect electronic devices and induce significant voltages in adjacent power lines,which is dangerous for operating *** numerous investigations have focused on modeling the EMF of traction networks and power lines,the challenge of determining the three-dimensional electromagnetic fields near metal supports during the flow of a short-circuit current through them is yet to be *** this case,the field has a complex spatial structure that significantly complicates the calculations of *** study proposes a methodology,algorithms,software,and digital models for determining the EMF in the described emergency *** the modeling process,the objects being studied were represented by segments of thin wires to analyze the distribution of the electric charge and calculate the intensities of the electric and magnetic *** approach was implemented in the Fazonord software,and the modeling results show a substantial increase in EMF levels close to the support,with a noticeable decrease in the levels as the distance from it *** procedure implemented in the commercial software Fazonord is universal and can be used to determine electromagnetic fields at any electrical power facility that includes live parts of limited *** on the proposed procedure,the EMF near the supports of overhead power lines and traction networks of various designs could be determined,the EMF levels at substations can be calculated,and the influence of metal structures located near traction networks,such as pedestrian crossings at railway stations,can be considered.

关键词： Power supply systems AC railways Emergency conditions Electromagnetic fields near supports Modeling Electromagnetic safety

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Features of the long-term transformation of the Krasnodar reservoir,near the mouth of the Kuban River,Russia

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Journal of Geographical Sciences 2021年第12期31卷 1895-1904页

作者： POGORELOV Anatoly LAGUTA andrey KISELEV Evgeny LIPILIN Dmitry Kuban State University Krasnodar 350040Russia Aerogematica LLC Krasnodar 350063Russia Kuban State Agrarian University Named after I.T.Trubilin Krasnodar 350044Russia Tuapse Branch of the Russian State Hydrometeorological University Krasnodar RegionTuapse 352800Russia

The article considers the long-term(1941-2018)transformation of the Krasnodar valley reservoir,the largest in the North *** main functions of the Krasnodar reservoir are irrigation of rice systems and flood protection of land in the Krasnodar reservoir region and the Republic of *** to topographic maps,Landsat satellite images(1974-2018)and field observations(2016-2018),four stages of transformation of the floodplain reservoir are *** selected stages are characterized by both natural causes(the transformation of the filling deltas into the extended deltas,etc.)and man-made causes(runoff diversions in the delta areas,etc.).The key factor of transformation is the formation of deltas of rivers flowing into the *** of the selected stages,against the background of a gradual reduction in the area and volume of the reservoir,is characterized by the peculiarities of the formation of river deltas with the formation of genetically homogeneous sections of delta *** the period of operation of the reservoir,the delta of the main Kuban River moved up to 32.4 km and took away an area of 35.4 km^(2) of the *** the formation of the deltas of the Kuban and Belaya rivers,a bridge was formed on the Krasnodar *** evolution of the delta regions led to the division of the reservoir into two autonomous *** total area of the delta regions was 85.9 km^(2) by 2018,i.e.,21% of the initial area of the *** transformation of the Krasnodar reservoir leads to a decrease in its regulated volume and gradual degradation.

关键词： Krasnodar reservoir sedimentation siltation transformation delta formation Landsat

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Machine learning-based method to adjust electron anomalous conductivity profile to experimentally measured operating parameters of Hall thruster

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Plasma Science and Technology 2022年第6期24卷 148-156页

作者： andrey SHASHKOV Mikhail TYUSHEV Alexander LOVTSOV Dmitry TOMILIN Dmitrii KRAVCHENKO JSC'Keldysh Research Center' 8 Onezhskaya St.Moscow 125438Russia

The problem of determining the electron anomalous conductivity profile in a Hall thruster,when its operating parameters are known from the experiment,is *** solve the problem,we propose varying the parametrically set anomalous conductivity profile until the calculated operating parameters match the experimentally measured ones in the best *** axial 1D3V hybrid model was used to calculate the operating parameters with parametrically set *** of the conductivity profile was performed using Bayesian optimization with a Gaussian process(machine learning method),which can resolve all local minima,even for noisy *** calculated solution corresponding to the measured operating parameters of a Hall thruster in the best way proved to be unique for the studied operating modes of *** local plasma parameters were calculated and compared to the measured ones for four different operating *** results show the qualitative *** agreement between calculated and measured local parameters can be improved with a more accurate model of plasma-wall interaction.

关键词： Hall thruster anomalous conductivity machine learning Bayesian optimization Gaussian process electric propulsion

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Autonomous UAV 3D trajectory optimization and transmission scheduling for sensor data collection on uneven terrains

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Defence Technology（防务技术） 2023年第12期30卷 154-160页

作者： andrey V.Savkin Satish C.Verma Wei Ni School of Electrical Engineering and Telecommunications University of New South WalesSydneyAustralia Data61 CSIROCanberraACT2601Australia

This paper considers a time-constrained data collection problem from a network of ground sensors located on uneven terrain by an Unmanned Aerial Vehicle(UAV),a typical Unmanned Aerial System(UAS).The ground sensors harvest renewable energy and are equipped with batteries and data *** ground sensor model takes into account sensor data buffer and battery *** asymptotically globally optimal method of joint UAV 3D trajectory optimization and data transmission schedule is *** developed method maximizes the amount of data transmitted to the UAV without losses and too long delays and minimizes the propulsion energy of the *** developed algorithm of optimal trajectory optimization and transmission scheduling is based on dynamic *** simulations demonstrate the effectiveness of the proposed algorithm.

关键词： Unmanned aerial system UAS Unmanned aerial vehicle UAV Wireless sensor networks UAS-Assisted data collection 3D trajectory optimization Data transmission scheduling

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Energy-efficient joint UAV secure communication and 3D trajectory optimization assisted by reconfigurable intelligent surfaces in the presence of eavesdroppers

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Defence Technology（防务技术） 2024年第1期31卷 537-543页

作者： Huang Hailong Mohsen Eskandari andrey V.Savkin Wei Ni The Department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Electrical Engineering and Telecommunications University of New South WalesSydney2052Australia Data61 CSIROAustralia

We consider a scenario where an unmanned aerial vehicle(UAV),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple *** friendly reconfigurable intelligent surfaces(RISs) help to secure the UAV-target communication and improve the energy efficiency of the *** formulate an optimization problem to minimize the energy consumption of the UAV,subject to the mobility constraint of the UAV and that the achievable secrecy rate at the target is over a given *** present an online planning method following the framework of model predictive control(MPC) to jointly optimize the motion of the UAV and the configurations of the *** effectiveness of the proposed method is validated via computer simulations.

关键词： Unmanned aerial systems(UASs) Unmanned aerial vehicle(UAV) Communication security Eaves-dropping Reconfigurable intelligent surfaces(RIS) Autonomous navigation and placement Path planning Model predictive control

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Influence of Al-5Ti-1B master alloy addition on the grain size of AZ91 alloy

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Journal of Magnesium and Alloys 2017年第3期5卷 313-319页

作者： andrey Koltygin Viacheslav Bazhenov Uralboy Mahmadiyorov National University of Science and Technology“MISiS” Leninskiy pr.4Moscow 119049Russia

The mechanical properties of castings depend on the grain *** is evidence that titanium and boron(Al-5Ti-1B master alloy)affect the grain size of magnesium ***,the influence of the addition of 0-1 wt.%of Al-5Ti-1B master alloy on the grain size of AZ91 magnesium alloy was *** of the alloy was performed in steel and corundum *** study the effect of cooling rate on grain size,cylindrical samples were cast in steel and fireclay *** Al-5Ti-1B master alloy addition did not change the phase composition of the AZ91 *** study demonstrates that the addition of Al-5Ti-1B did not contribute to the grain refinement of the AZ91 alloy,but rather led to its coarsening for samples cast in both the steel and fireclay *** the holding time after the addition of the Al-5Ti-1B master alloy from 15 to 110 minutes also did not lead to significant grain *** mechanical properties of the AZ91 alloy samples slightly improved after Al-5Ti-1B addition.

关键词： AZ91 magnesium alloy Grain refinement Al–5Ti–1B master alloy Ti addition Growth restriction factor

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Influence of Rayleigh-Taylor Instability on Impurity Dynamics during Column Back-Flushing Filtration

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Fluid Dynamics & Materials Processing 2024年第12期20卷 2709-2720页

作者： Yanina N.Parshakova andrey Ivantsov Institute of Continuous Media Mechanics Ural Branch of the Russian Academy of SciencesPerm614013Russia

During the manufacturing or processing of materials,large volumes of water of the required quality are often *** water treatment and water purification is the process of removing impurities and pollution from the considered *** obtain liquid with specified quality parameters,complex systems of filters and treatment facilities are generally *** this work,the cleaning process for a filtration column is ***-dimensional numerical simulations of flow in a columnar array consisting of a porous medium are *** particular,a model case corresponding to laboratory conditions is examined,with potassium salt being considered as a *** is assumed that the vertical column is a desalination system,as a result of which saturation and clogging of the pores of the medium occur;at the end of the operating cycle of such a filter,washing is *** modeling is implemented through the Brinkman approach taking into account density *** is found that owing to density stratification and related effects,clean water moves in the central part of the filter,while contaminants near the side walls remain motionless for a long time.A solution to this problem is presented by changing the flow rate of supplied water.

关键词： Filtration column binary mixture Rayleigh-Taylor instability Brinkman model

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Preface to the Special Issue on Modeling and Data Analysis Methods for the SMILE mission

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Earth and Planetary Physics 2024年第1期8卷 1-4页

作者： TianRan Sun Hyunju Connor andrey Samsonov National Space Science Center Chinese Academy of SciencesBeijing 100190China NASA Goddard Space Flight Center US Mullard Space Science Laboratory University College LondonUK

The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)project(http://***/smile/,https://***/web/smile/mission)is a joint spacecraft mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)with an expected launch in *** aims to study the global interactions of solar wind–magnetosphere–ionosphere innovatively by imaging the Earth’s magnetosheath and cusps in soft X-rays and the northern auroral region in ultraviolet(UV)while simultaneously measuring plasma and magnetic field parameters in the solar wind and magnetosheath along a highly-elliptical and highly-inclined *** special issue is composed of 22 articles,presenting recent progress in modeling and data analysis techniques developed for the SMILE *** this preface,we categorize the articles into the following seven topics and provide brief summaries:(1)instrument descriptions of the Soft X-ray Imager(SXI),(2)numerical modeling of the X-ray signals,(3)data processing of the X-ray images,(4)boundary tracing methods from the simulated images,(5)physical phenomena and a mission concept related to the scientific goals of SMILE-SXI,(6)studies of the aurora,and(7)ground-based support for SMILE.

关键词： SMILE X-ray imaging magnetosphere auroral ionosphere

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The Behavior of a Gas Bubble in a Square Cavity Filled with a Viscous LiquidUndergoing Vibrations

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Fluid Dynamics & Materials Processing 2024年第11期20卷 2417-2429页

作者： Tatyana Lyubimova Yulia Garicheva andrey Ivantsov Computational Fluid Dynamics Lab Institute of Continuous Media MechanicsUral Branch of the Russian Academy of SciencesPerm614013Russia Theoretical Physics Department Perm State UniversityPerm614990Russia

External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. Thecomputational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of squarecross-section, which undergoes linearly polarized translational oscillations in weightless conditions, has been carried out. Under vibrations, the bubble moves towards the wall of the vessel with acceleration determined by theamplitudes and frequency of vibrations. Near the wall, at a distance of the order of the thickness of the viscousStokes boundary layer, the effects of viscosity become more important and, as a result, the bubble is repelled fromthe wall. After some oscillations, equilibrium conditions are attained where the attractive force balances the repulsive force;accordingly, the average position of the bubble ceases to change. The numerical modelling shows thatthe average behaviors of a deformable bubble near a wall under normal and tangential vibration are similar.

关键词： Bubble vibrations viscosity average force

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Dynamics of magnetic flux tubes and IR-variability of young stellar objects

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Research in Astronomy and Astrophysics 2018年第8期18卷 13-20页

作者： Sergey Khaibrakhmanov Alexander Dudorov andrey Sobolev Kourovka Astronomical Observatory Ural Federal University Theoretical Physics Department Chelyabinsk State University

We simulate the dynamics of slender magnetic flux tubes （MFTs） in the accretion disks of T Tauri stars. The dynamical equations of our model take into account aerodynamic and turbulent drag forces, and the radiative heat exchange between the MFT and ambient gas. The structure of the disk is calculated with the help of our MHD model of the accretion disks. We consider the MFTs formed at distances of 0.027 - 0.8 au from the star with various initial radii and plasma betas β0. The simulations show that MFTs with a weak magnetic field （β0 = 10） rise slowly with speeds less than the speed of sound. MFTs withβ0 = 1 form an outflowing magnetized corona above the disk. Strongly magnetized MFTs （β0 = 0.1） can cause outflows with velocities 20 - 50 km s-1. The tubes rise periodically over times from several days to several months according to our simulations. We propose that periodically rising MFTs can absorb stellar radiation and contribute to the IR-variability of young stellar objects.

关键词： accretion disks- instabilities- magnetohydrodynamics (MHD) - protoplanetary disks

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