441 research outputs found

    The topography of the field and flux inside and above the surfaces of ferromagnetic plates during their contact and contactless magnetization

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    Modeling and experimental studies of the spatial distributions of the field and flux inside and above the surface of ferromagnetic plates of different dimension types, which were locally magnetized by U-shaped electromagnets, were performed. It was established that the location of a magnetic inhomogeneity in the interpole zone of an electromagnet substantially affects the results of a local measurement of the coercive force using a demagnetization current. It is shown that the presence of a gap in the magnetic circuit impairs the magnetization of the interpole zone of an object to a higher degree than the magnetization of the near-pole zone. Recommendations on the concentration of the magnetic flux in the interpole zone via a decrease in the interpole distance of the electromagnet are given. Possible locations of internal-field probes that provide local measurements of the magnetic properties of a substance are determined. © 2013 Pleiades Publishing, Ltd

    Magnetic and acoustic characteristics of steel 30CrMnSiA after rolling and pressing

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    A group of magnetic and acoustic parameters of the cold-deformed 30CrMnSiA steel is determined. It has been revealed that the coercive force of this steel starts to decrease steadily at degrees of plastic deformation higher than 6%. A hypothesis is put forward on the relaxation of stresses of the first kind as a result of flat pressing after rolling of steel plates. To test the possibility of determining the degree of deformation of the 30CrMnSiA steel by ultrasound measurements, the propagation velocities of longitudinal, transverse, and Rayleigh waves are determined. The change in the velocity of longitudinal ultrasonic waves is 0.8% at deformation degrees ranging from 10 to 20%. The velocity of transverse and Rayleigh ultrasonic waves increases monotonically over the entire range of deformations, with a change in their velocity of 2.5% and 2.2% respectively. Thus, the most suitable parameter for determining the degree of deformation is the propagation velocity of transversal ultrasonic waves. © 2018 Author(s)

    Three-dimensional distribution of the magnetic field and the flux in locally magnetized two-layer ferromagnetic objects

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    Numerical simulation of the spatial distribution of the magnetic field and the flux in two-layer objects is executed. The possibility of measuring the depth of a highly coercive layer on a soft magnetic core by the magnetic field measured on the surface of the object in the interpolar space of a U-shaped electromagnet is theoretically and experimentally shown. © 2016 Author(s)

    Cole-Hopf Like Transformation for Schr\"odinger Equations Containing Complex Nonlinearities

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    We consider systems, which conserve the particle number and are described by Schr\"odinger equations containing complex nonlinearities. In the case of canonical systems, we study their main symmetries and conservation laws. We introduce a Cole-Hopf like transformation both for canonical and noncanonical systems, which changes the evolution equation into another one containing purely real nonlinearities, and reduces the continuity equation to the standard form of the linear theory. This approach allows us to treat, in a unifying scheme, a wide variety of canonical and noncanonical nonlinear systems, some of them already known in the literature. pacs{PACS number(s): 02.30.Jr, 03.50.-z, 03.65.-w, 05.45.-a, 11.30.Na, 11.40.DwComment: 26 pages, no figures, to be appear in J. Phys. A: Math. Gen. (2002

    Complex application of magnetic and magnetoacoustic parameters in the structuroscopy of ferromagnetic materials

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    The set of magnetic parameters and amplitude-frequency spectral characteristics of magnetoacoustic emission (MAE) of a large group of metal ferromagnetic materials differing in their physical properties and size are investigated. It is shown that the change in critical fields determined by the shape of the magnetization curve and the hysteresis loop of bulk samples with an increase in the annealing temperature of cold-deformed steel 20G is 1.5-3 times greater than the change in such well-known parameters for estimating the stress-strain state, such as coercive force and residual magnetic induction. It has been established that the amplitude of magnetoacoustic emission correlates with the residual magnetic induction, which makes it possible to recommend the complex application of these testing parameters in scanning systems of structuroscopy of ferromagnetic materials. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 18-38-00253The research was carried out within the state assignment of Minobrnauki of Russia (theme “Diagnostics” No. АААА-А18-118020690196-3), supported in part by RFBR (project No. 18-38-00253)

    АНАЛИЗ ЭНЕРГОЭФФЕКТИВНОСТИ РЕЖИМОВ РАБОТЫ ЭЛЕКТРИЧЕСКИХ СИСТЕМ С ТЯГОВЫМИ НАГРУЗКАМИ

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    Innovative scenarios of reliable energy supply of transportation process aimed at reducing the specific energy consumption and increase energy efficiency of the systems of electric traction. The paper suggests innovative energy saving directions in traction networks of railways and new circuit solutions accessing traction substations in energy systems networks, ensure energy security of the transportation process. To ensure the energy security of rail transport special schemes were developed to propose the concept of external power traction substations, which would increase the number of connections to the networks of 220 – 330 kV, as well as the creation of transport and energy corridors, development of its own supply of electric networks of 110 kV substations and mobile RP-110 kV of next generation. Therefore, the investment program of the structures owned by the Ukrainian Railways (Ukrzaliznytsia) need to be synchronized in their technological characteristics, as well as the criteria of reliability and quality of power supply with the same external energy investment programs. It is found that without any load on left or right supplying arm one of two less loaded phases of traction transformer begins generating specific modes in the supplying three-phase line. Thus, modes of mobile substation cause leakage in one of the phases of the supply line of traction transformers of active-capacitive current, and as a result generating energy in the main power line of 154 kV, which is fixed and calculated by electricity meters. For these three phase mode supply network is necessary to use 1st algorithm, i.e. taking into account the amount of electricity as the energy in all phases. For effective application of reactive power compensation devices in the AC traction power supply systems it is proposed to develop regulatory documentation on necessity of application and the order of choice of parameters and placement of compensation systems taking into account operation mode of power systems and the use of software systems with imitation of instantaneous interrelated schemes of transport loads.В статье предложены инновационные направления энергосбережения в тяговых сетях железных дорог и новые схемотехнические решения присоединения тяговых подстанций к сетям энергосистем, обеспечивающие энергобезопасность перевозочного процесса. Дано обоснование необходимости расчета тяговых подстанций по векторному методу трехфазного потребления энергии от подстанций НЭК «Укрэнерго».В статье предложены инновационные направления энергосбережения в тяговых сетях железных дорог и новые схемотехнические решения присоединения тяговых подстанций к сетям энергосистем, обеспечивающие энергобезопасность перевозочного процесса. Дано обоснование необходимости расчета тяговых подстанций по векторному методу трехфазного потребления энергии от подстанций НЭК «Укрэнерго»

    Comment on ``the Klein-Gordon Oscillator''

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    The different ways of description of the S=0S=0 particle with oscillator-like interaction are considered. The results are in conformity with the previous paper of S. Bruce and P. Minning.Comment: LaTeX file, 5p
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