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Search results for: ferromagnetic
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Localization and identyfication of ferromagnetic objects
PublicationA compact ferromagnetic object placed in the earthly magnetic field causes disturbance of this field. This disturbance is associated with magnetization of the object. Ferromagnetic objects have induced and can also have permanent magnetization. In methods of locating and identifying ferromagnetic objects usually is using the model of the dipol moment. Determination of the position and values of the extremes of the magnetic field...
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Magnetic properties of ferromagnetic Pu2Pt3Si5
PublicationThe structural, magnetic, and thermodynamic properties of a new plutonium based compound, Pu2Pt3Si5, are reported. Single crystals produced by a Sn-flux technique have been analyzed showing a ferromagnetic behavior at 58 K. Pu2Pt3Si5 crystallizes in the U2Co3Si5-type orthorhombic Iabm structure (s.g. 72) with atomic parameters a = 9.9226(2) Å, b = 11.4436(2) Å and c = 6.0148(1) Å. The effective (leff 0.74 lB/Pu) and saturated (rsat...
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Locating and Identifying Ferromagnetic Objects
PublicationThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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Locating and Identifying Ferromagnetic Objects
PublicationThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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Analysis of degaussing process of ferromagnetic objects
PublicationResults of the analytical and numerical analysis of the degaussing process phenomena of ferromagnetic objects were presented in this paper. The screening effectiveness of the electromagnetic field of magnetic screens in most cases depends on thickness, conductivity, magnetic permeability of the screen and angular frequency of degaussing currents. The magnetic field inside thin-layer ferromagnetic object was presented in this paper....
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MAKING OF FERROMAGNETIC ELLIPTICAL SHELL IN TRANSVERSE MAGNETIC
PublicationA ferromagnetic object, located in the Earth’s magnetic field, changes its distribution. Through measuring such disturbances, one can locate the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, and its task is to eliminate the disturbances in the distribution of the Earth’s magnetic field.
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Measurements of the mechanical Barkhausen noise in ferromagnetic steels
PublicationArtykuł ten przedstawia wpływ zmian w mikrostrukturze stali P91, powstałych w skutek obróbki cieplnej, na właściwości mechanicznego efektu Barkhausena (MeBN). Parametry takie jak amplituda obwiedni napięcia skutecznego (RMS) MeBN oraz położenie maksimum tejże obwiedni porównywane są, pod kątem czułości na obróbkę cieplną materiału, z klasycznymi parametrami takimi jak pole koercji magnetycznej czy też twardość mechaniczna HV. Największą...
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Scalar gradiometer system of detection of ferromagnetic objects
PublicationW pracy opisano metody detekcji ukrytych obiektów. Omówiono pole magnetyczne związane z obiektem ferromagnetycznym umiszczonym w ziemskim polu magnetycznym. Przedstawiono gradiometryczny system detekcji obiektów ferromagnetcyznych z prezentacją wyników badań eksperymentalnych.
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Analysis of magnetic field of Hemholtz's coils and ferromagnetic objects
PublicationThe 3-axis fluxgate magnetometer requires conducting a precise calibration in the magnetic field whose value is determined and which is characterized by the high uniformity of the distribution of the field, especially along the axis of the sensors. The generation of the magnetostatic field characterized by the high uniformity, can be achieved by using the Helmholtz's coils. The requirements of the uniformity of distribution of...
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Ferromagnetic nanocrystallites in the SiO2 - PbO - Fe2O3 glass system
PublicationThe structure of 50% SiO2 - 35% PbO - 15% Fe2O3, 50% SiO2 - 30% PbO - 20% Fe2O3 and 50% SiO2 - 25% PbO - 25% Fe2O3 (in mol%) glass was investigated by the means of AFM microscopy and X-ray diffraction. Observation by the atomic force microscopy shows that each of prepared iron oxide glass doesn't have homogeneous structure and some nanocrystallites were detected. Next, test with neodymium magnet found out strong magnetic properties...
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The influence of the filler on the magnetic field distribution in ferromagnetic objects.
PublicationDuże obiekty ferromagnetyczne umieszczone w zewnętrznym polu magnetycznym (np. ziemskim polu magnetycznym) ulegają namagnesowaniu. W pewnych przypadkach konieczna jest demagnetyzacja obiektu ferromagnetycznego. Demagnetyzacja polega na umieszczeniu obiektu w wytworzonym w układzie zewnętrznym polu magnetycznym o określonych właściwościach. Jeżeli obiekt ferromagnetyczny posiada duże rozmiary, wówczas jego demagnetyzacja jest problemem...
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Implementation of localization and identification of ferromagnetic objects algorithm in labview enviroment
PublicationThe problem with detecting dangerous objects is still a matter of concern today. One of the methods of detecting dangerous objects is the magnetic method. While measuring a magnetic field in the surrounding of objects with ferromagnetic properties, it is possible to detect, localize and identify such object.
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Analysis of ship's magnetic field with consideration of inner ferromagnetic devices
PublicationThis paper presents computer simulations of ship’s magnetic signatures. The influence of ship’s inner ferromagnetic devices on the signature was presented. The magnetic fields of the ship’s model were calculated in Opera 3D 18R2. The model was built from thin plates. The new, thin plate boundary condition was introduced on all ship’s surfaces.
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Analysis of magnetic field inside thin-layer ferromagnetic objects
PublicationResults of the numerical analysis of the magnetic field inside an infinitely long, thin-layer ferromagnetic pipe with and without a barrier were presented in this paper. Two wires with current symmetrically placed on two sides of the pipe are the sources of magnetic field. Numerical calculations for the quasi-steady state for chosen frequency band were carried out in the Flux 2D.
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Localization of ferromagnetic objects via magnetometric method near equator
PublicationIstnieje wiele metod wykrywania ukrytych w ziemi obiektów. Metody te można podzielić na pasywne i aktywne. Do metod pasywnych należy metoda magnetometryczna. Obiekt ferromagnetyczny zaburza w swoim otoczeniu równomierność pola magnetycznego. Korzystając z metody magnetometrycznej można to zaburzenie zmierzyć i wykryć obiekt. W pracy przedstawiono nową metodę lokalizacji obiektów ferromagnetycznych metodą magnetometryczną znajdujących...
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Detection of ferromagnetic objects in local magnetic anomaly of the Baltic Sea
PublicationIn geological researches several kinds of methods are applied to discovering the natural resources. Planes, helicopters and UAVs (UnmAnned Vehicle) are used in researches in large areas. The gravity, electromagnetic and magnetic methods, which are used in geological researches, are presented in this paper. The special attention was paid to magnetic systems installed on mobile platforms. The magnetic field of the Earth obtained...
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System of wireless magnetic sensors for detection and identification of ferromagnetic vehicles
PublicationThe paper presents the results of deformation of the Earth's magnetic field by land vehicles. Basing on the analysis of the shape of the magnetic field deformation, it is possible to detect and identify a vehicle. In order to eliminate the interference of the Earth's magnetic field by the environment, the measurements were performed in a differential configuration. Under a development project a wireless system of magnetic sensors...
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Carbon Nanotubes Grown with Non-Ferromagnetic Catalysts in Alcohol CVD
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Effect of rotating magnetic field on ferromagnetic structures used in hyperthermia
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Tuning the ferromagnetic phase in the CDW compound SmNiC2 via chemical alloying
PublicationWe report a study on tuning the charge density wave (CDW) ferromagnet SmNiC2 to a weakly coupled superconductor by substituting La for Sm. X-ray diffraction measurements show that the doped compounds obey Vegard’s law, where La (Lu) alloying expands (shrinks) the lattice due to its larger (smaller) atomic size than Sm. In the series Sm1−xLaxNiC2, CDW transition (TCDW =148K) for SmNiC2 is gradually suppressed, while the ferromagnetic...
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Iron filled single-wall carbon nanotubes – A novel ferromagnetic medium
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Analysis of the influence of ferromagnetic contaminations in plastics on the measurements of disturbances of magnetic field of the Earth
PublicationPlastics can be contaminated with small particles or filings with ferromagnetic properties. These contaminations cause significant disturbances in the magnetic field in the case of taking measurements of very low magnetic fields. The analysis of the influence of contaminated plastics on magnetic measurements is presented in this paper.
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Shape Memory Polyurethane Materials Containing Ferromagnetic Iron Oxide and Graphene Nanoplatelets
PublicationIntelligent materials, such as memory shape polymers, have attracted considerable attention due to wide range of possible applications. Currently, intensive research is underway, in matters of obtaining memory shape materials that can be actuated via inductive methods, for example with help of magnetic field. In this work, an attempt was made to develop a new polymer composite—polyurethane modified with graphene nanoplates and...
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Half-order analytical modelling of ferromagnetic sheet. Validation with finite elements simulation
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Analysis of magnetic field distribution inside ferromagnetic thin shells during degaussing process
PublicationAnalysis of the demagnetization of a large ferromagnetic object like a ship, was conducted. The approximate mathematical model in the form of a long cylindrical shell of constant magnetic permeability was applied. The discrete degaussing winding was assumed and the current density and magnetic flux density distribution in the ferromagnetic shell wall were determined. Based on the frequential and temporal analysis the recommended...
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Microscopic impact of creep damage incipience and development on the magnetic properties of ferromagnetic Cr-Mo steel
PublicationPokazano wyniki badań emisji magneto-akustycznej (EMA0 oraz magnetostrykcji dla stali P22 w stanie dostawy i po ekploatacji. Wyniki te pokazują, że maksimum EMA jest skorelowane z maksimum pochodnej magnetostrykcji. Badania morfologii wydzieleń w granicach ziarn i w ich wnętrzu potwierdzają tezę, iż te pierwsze są główną przyczyną zmniejszania natężenia EMA. Zaproponowano prosty model tłumaczący ilościowo funkcję zmian natężenia...
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Ferromagnetic nanoparticles imaging by means of Magnetic Force Microscopy
Open Research DataFerromagnetic nanoparticles can be used as building blocks for advanced thin film magnets, and can also be used in data storage and biomedical technologies. Nano-crystalline ferrites with the chemical formula NixZn (1 - x) Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0 show anti-corrosion properties and suppress electromagnetic interference, in the case...
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation...
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation threshold...
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Disturbances of magnetic field in surrounding of mobile, metallic plate. Detection of ferromagnetic objects in strong local magnetic anomaly
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Magnetic signature reproduction of ferromagnetic ships at arbitrary geographical position, direction and depth using a multi-dipole model
PublicationThe reproduction of magnetic signatures is an important issue concerning the safety of ship traffic, as well as the identification and classification of vessels. Moreover, military applications of magnetic signatures and their reproduction refer to the activation or protection against activation of magnetic naval mines. Previous works on this subject focused on recording and replicating the signatures under the same conditions...
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Wpływ kształtu otwartego obiektu ferromagnetycznego na pole magnetyczne.Influence of shape of open ferromagnetic object on magnetic field.
PublicationObiekt o właściwościach ferromagnetycznych znajdujący się w ziemskim polu magnetycznym zaburza równomierność tego pola. Przestrzenny rozkład zaburzenia pola zależy od wielu czynników, w tym między innymi od rozmiarów i kształtu obiektu, od jego właściwości ferro-magnetycznych i od położenia względem wektora ziemskiego pola magnetycznego. Na podstawie pomiaru rozkładu pola magnetycznego wokół obiektu można dokonać lokalizacji i...
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Lokalizacja obiektu ferromagnetycznego metodą magnetometryczną na równiku = Localization of ferromagnetic objects via magnetometric method near equator
PublicationIstnieje wiele metod wykrywania ukrytych w ziemi obiektów. Metody te można podzielić na pasywne i aktywne. Do metod pasywnych należy metoda magnetometryczna. Obiekt ferromagnetyczny zaburza w swoim otoczeniu równomierność pola magnetycznego. Korzystając z metody magnetometrycznej można to zburzenie zmierzyć i wykryć obiekt. W pracy przedstawiono nową metodę lokalizacji obiektów ferromagnetycznych metodą magnetometryczną znajdujących...
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Otrzymywanie makroskopowego kompozytu nadprzewodząco-ferromagnetycznego na bazie YBa2Cu3O7-x = Obtaining the macroscopic superconductive ferromagnetic composite based on YBa2Cu3O7-x
PublicationPublikacja przedstawia technologię otrzymywania kompozytów nadprzewodząco-ferromagnetycznych na bazie porowatego ceramicznego nadprzewodnika wysokotemperaturowego YBCO o porach otwartych.
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Evaluation by means of magneto-acoustic emission and Barkhausen effect of time and space distribution of magnetic flux density in ferromagnetic plate magnetized by a C-core
PublicationPokazano wyniki badań emisji magnetoakustycznej (EMA) i efektu Barkhausena (HEB) dla dwóch płyt stalowych o różnych wymiarach. Wyniki te są porównane z wynikami modelowania zjawiska EMA z wykorzystaniem metody elementów skończonych z uwzględniem efektu prądów wirowych. Uzyskano zadawalające dopasowanie modelu, który odtwarzał poszerzenie maksimum EMA oraz przesunięcie fazowe i zmianę amplitudy HEB.
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Zastosowanie metody równań całkowych w analizie pola ekranującego obiektów ferromagnetycznych.Application of integral equations method to shield field analysis of ferromagnetic object.
PublicationDuże obiekty ferromagnetyczne, jakimi są okręty, powodują zaburzenia w rozkładzie ziemskiego pola ma-gnetycznego. Dla zredukowania tego zaburzenia na okrętach umieszcza się specjalne uzwojenia, których ce-lem jest wytworzenie pola magnetycznego usuwającego zmiany wywołane obecnością ferromagnetyka w zewnętrznym polu ziemskim. Obliczania rozkładu tych uzwojeń wiąże się z koniecznością znalezienia rozkładu pola magnetycznego.Zastosowanie...
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Analiza pola magnetycznego wewnątrz i na zewnątrz cienkościennego obiektu ferromagnetycznego = An analisis of magnetic field inside and outside thin-walled ferromagnetic object
PublicationAnomalia wnoszona przez obiekt ferromagnetyczny znajdujący się w ziemskim polu magnetycznym związana jest z jego namagnesowaniem stałym i indukowanym.W pracy przedstawiono wyniki badań symulacyjnych dotyczące rozkładu indukowanego pola magnetycznego wewnątrz i na zewnątrz obiektu ferromagnetycznego odpowiadającemu kadłubowi okrętu. Analizę numeryczną przeprowadzono w pakiecie OPERA 3d.
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Magnetic signature reproduction of ferromagnetic ships at arbitrary geographical position, direction and depth using a multi-dipole model – source and verification dataset with description
Open Research DataThe dataset include source synthetic magnetic data concerning the corvette-type ship numeric model. The data are for 6 locations around the World with different V1 ÷ V6 Earth magnetic field values. The attached data is in Matlab. MAT format, but the data can also be used in Octave software.
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Mirosław Wołoszyn dr hab. inż.
PeopleMirosław Wołoszyn born in 1963 in Gdynia. He received the M.Sc. degree in 1987, the Ph.D. degree in 1997, and the D.Sc. (‘habilitation’) degree in 2013, all from the Gdańsk University of Technology. Since 1987 he has been with the above university, where he is currently Associate Professor of Electrical Engineering. His research interests include localization and identification of ferromagnetic objects by means of the magnetometric...
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Mobilny system do detekcji obiektów ferromagnetycznych z magnetometrami pompowanymi optycznie
PublicationW pracy przedstawiono mobilny system do detekcji obiektów ferromagnetycznych. Każdy obiekt ferromagnetyczny zaburza w swoim otoczeniu równomierność pola magnetycznego Ziemi. Zaburzenie to może być zmierzone za pomocą precyzyjnych magnetometrów. W prezentowanym mobilnym systemie zastosowano magnetometry pompowane optycznie pracujące w układzie różnicowym. W pracy opisano magnetometryczny system do detekcji obiektów ferromagnetycznych,...
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The influence of compensate coils on own ship magnetic field
PublicationA ferromagnetic object placed in the earth magnetic field causes a local disturbance in this field distribution. The field distribution disturbance is a function of many arguments like the dimensoins and shape of the object, its ferromagnetic properties ande its positon in relation to the earth magnetic field. in order to minimize the influence of this disturbance one places compensate coils on the ship. Some chosen results of...
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Analysis of magnetic disturbances of air platform caused by induced magnetisation
PublicationMagnetometric systems installed on air platforms like airplanes or helicopters are equipped in compensators of magnetic disturbances. Time changes of the platform's position caused generation of magnetic disturbances. The permanent and induced magnetization of ferromagnetic elements and eddy currents induced in conducting parts of the platform are sources of these disturbances. The linear model of magnetic disturbances of platforms...
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Ferro- and antiferro-magnetism in (Np, Pu)BC
PublicationTwo new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of {Np,Pu} BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below T-N = 44 K, whereas ferromagnetic ordering was found for NpBC below T-C = 61 K. Heat capacity measurements prove the bulk character...
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Enhanced Mobility and Large Linear Nonsaturating Magnetoresistance in the Magnetically Ordered States of TmNiC2
PublicationWe have studied the magnetic, magnetotransport, and galvanomagnetic properties of TmNiC2. We find that the antiferromagnetic and field induced metamagnetic and ferromagnetic orderings do not suppress the charge density wave. The persistence of Fermi surface pockets, open as a result of imperfect nesting accompanying the Peierls transition, results in an electronic carriers mobility of the order of 4 × 103 cm2 V−1 s−1 in ferromagnetic...
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Magnetic signatures of land vehicles
PublicationThe results of numerical simulations of the magnetic field surrounding of land vehicles' models have been presented in this paper. Vehicle containing of ferromagnetic elements distorts the Earth's magnetic field. This distortion can be measured by magnetometers. It is possible to detect and identify an object on the basis of its magnetic signature.
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Half-Order Modeling of Saturated Synchronous Machine
PublicationNoninteger order systems are used to model diffusion in conductive parts of electrical machines as they lead to more compact and knowledge models but also to improve their precision. In this paper a linear half-order impedance model of a ferromagnetic sheet deduced from the diffusion of magnetic field is briefly introduced. Then, from physical considerations and finite elements simulation, the nonlinear half-order impedance model...
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Model of ship's magnetic signature
PublicationShips made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine...
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Multidipoles model of ship's magnetic field
PublicationShips made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine...
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Multidipoles model of ship's magnetic field
PublicationShips made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine...
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ANALIZA ROZKŁADU POLA MAGNETYCZNEGO WEWNĄTRZ OBIEKTU FERROMAGNETYCZNEGO
PublicationW artykule przedstawione zostały wyniki analizy rozkładu natężenia pola magnetycznego wewnątrz obiektu ferromagnetycznego. Obiekt ferromagnetyczny znajdujący się w zewnętrznym polu magnetycznym wywołuje jego zaburzenie, które może być podstawą do wykrycia tego obiektu. Pożądanym zatem jest, aby kompensować to zaburzenie przez zastosowanie cewek kompensujących umieszczonych wewnątrz obiektu. Analiza rozkładu natężenia pola magnetycznego...