Academic literature on the topic 'Magnetization vector'
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Journal articles on the topic "Magnetization vector"
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Shi, Xiaoqing, Hua Geng, and Shuang Liu. "Magnetization Vector Inversion Based on Amplitude and Gradient Constraints." Remote Sensing 14, no. 21 (2022): 5497. http://dx.doi.org/10.3390/rs14215497.
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Magnetization vector inversion has been developed since it can increase inversion accuracy due to the unknown magnetization direction caused by remanence. However, the three components of total magnetizations vector are simultaneously inverted and then synthesized into the magnetization magnitude and direction, which increases the inherent non-uniqueness of the inversion. The positions of the three components of the magnetization vector are originally consistent. If there is a lack of constraints between them during the inversion process, they may be misaligned, resulting in a large deviation between the synthesized vector model and the ground truth. To address this issue and at the same time increase the accuracy of the edges of the inversion models, this paper proposes a magnetization vector inversion scheme with model and its gradients’ constraints by sparse Lp norm functions based on the amplitude of the three components of the magnetization vector instead of a single component to improve the accuracy of the inversion result. To evaluate the inversion accuracy performance, an improved evaluation index is also proposed in this paper, which can better evaluate the accuracy of the shape, position and magnetization amplitude of the inversion model. The proposed inversion method can recover the models with higher accuracy compared with traditional methods, indicated by the inverted model and the evaluation indexes. Simulation results based on the open-source SimPEG software and inversion on actual measured Galinge iron ore deposit (China) data verified the effectiveness and advantages of the proposed method.
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Li, Xiangdong, Shuang Liu, Yunxiang Liu, Fufeng Ding, Xiange Jian, and Xiangyun Hu. "High-precision magnetization vector inversion: application to magnetic data in the presence of significant remanent magnetization." Journal of Geophysics and Engineering 19, no. 6 (2022): 1308–19. http://dx.doi.org/10.1093/jge/gxac085.
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Abstract Magnetization vector inversion is essential for obtaining magnetization vector information from subsurface rocks. To obtain focused inversion results that better match the true magnetization distributions, sparse constraints are considered to constrain the objective function. A compact magnetization vector inversion method is proposed that can provide accurate inversion results for magnetic data with significant remanent magnetization. Considering the sparse constraint and the correlation between the three magnetization components with different directions, the L1-norm is modified and introduced into the inversion algorithm to obtain compact results. Furthermore, to reduce the computational cost, a randomized singular value decomposition is used to replace the traditional singular value decomposition and iteratively minimize the proposed objective function. Two synthetic models with different magnetization directions are developed to verify the performance of the proposed method. The results of magnetization vectors obtained by the proposed method are focused and accurate. Finally, the proposed method is applied to igneous rocks with strong remanent magnetization in the Haba River area of northwestern China. The distributions, directions of total magnetization and remanent magnetization of the medium-base igneous rocks are revealed by the sparse magnetization vector inversion method, which provides a wealth of information about the concealed deposits in the area.
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Ghalehnoee, Mohammad Hossein, and Abdolhamid Ansari. "Compact magnetization vector inversion." Geophysical Journal International 228, no. 1 (2021): 1–16. http://dx.doi.org/10.1093/gji/ggab330.
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SUMMARY Magnetization vector inversion (MVI) has attracted considerable attention in recent years since by this inversion both distribution of the magnitude and direction of the magnetization are obtained; therefore, it is easy to distinguish between the magnetic causative bodies especially when magnetic data are affected by different remanent magnetization. In this research, the compact magnetization vector inversion is presented: a 3-D magnetic modelling is proposed from surface data measurements to obtain compact magnetization distribution. The equations are solved in data-space least squares and the algorithm includes a combination of two weights as depth weighting and compactness weighting in the Cartesian system. The re-weighted compactness weighting matrix handles sparsity constraints imposed on the magnitude of magnetization for varying Lp-norms ($0 \le p \le 2$). The low value of the norm leads to more focused or compact inversion, and using a large value of p obtains a smooth model. The method is validated with two synthetic examples, the first is a cube that has significant remanent magnetization and the second consists of two causative cube bodies with significant different magnetization directions at different depths. The case study is the magnetic data of Galinge iron ore deposit (China) that the apparent susceptibility and magnetization directions are reconstructed. The compact model reveals that the results agree with drilling and geological information.
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Pedersen, Laust B., and Mehrdad Bastani. "Estimating rock-vector magnetization from coincident measurements of magnetic field and gravity gradient tensor." GEOPHYSICS 81, no. 3 (2016): B55—B64. http://dx.doi.org/10.1190/geo2015-0100.1.
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Poisson’s theorem relating components of the magnetic field to components of the gradient of the gravity vector assuming a common source has been cast into a general form. A given magnetization distribution in the terrain or in the underlying crust is propagated into the corresponding magnetic field through the gravity gradient tensor. Conversely, measured magnetic field anomalies and measured gravity gradient tensor anomalies can be used to estimate the unknown magnetization vectors without knowledge of the geometry of the sources. We have tested the method on recently acquired data over a greenstone belt in Northern Sweden. The topographic relief was sufficiently variable to dominate the measured gravity gradient tensor. In practice, we have concentrated on areas where the norm of the gravity gradient tensor reached a maximum so that there was a better chance of identifying isolated sources with well-defined density and magnetization. We have surrounded the selected points by a small window and used all the data lying within that window to estimate the magnetization vectors. We have compared the estimated amplitudes and directions of magnetization with those measured from selected rock samples in the area and found a relatively modest agreement. We have interpreted this as a result of two effects: (1) Measured magnetizations are generally lower than those estimated by this method, and we believe that this is related to the fact that the collection of samples in the field is biased because of a small number of outcrops in most parts of the area. (2) This analysis is biased toward high-amplitude magnetic anomalies; i.e., the estimation procedure works best for high-amplitude magnetic anomalies, in which case, the influence of neighboring anomalies is reduced. The estimated magnetization directions show a strong dominance of remanent magnetization over induced magnetization in agreement with laboratory measurements on rock samples from the area.
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MacLeod, Ian N., and Robert G. Ellis. "Quantitative Magnetization Vector Inversion." ASEG Extended Abstracts 2016, no. 1 (2016): 1–6. http://dx.doi.org/10.1071/aseg2016ab115.
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Ou, Yang, Qingtian Lü, Jie Zhang, et al. "Sparse Magnetization Vector Inversion Based on Modulus Constraints." Remote Sensing 17, no. 4 (2025): 597. https://doi.org/10.3390/rs17040597.
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Magnetization vector inversion (MVI) is an effective method for simultaneously determining the distribution of magnetization intensity and direction without knowing the direction of magnetization beforehand. Nevertheless, the presence of serious non-uniqueness in MVI imposes challenges in achieving accurate and reliable results. To improve the accuracy of MVI, we propose a method that incorporates a modulus constraint, informed by an analysis of the model constraints in two different frameworks. We employ a sparse operator on the magnetization magnitude and obtain an explicit expression for the magnetization components, establishing correlation constraints among them. Synthetic test results show that this method can achieve models with clear boundaries and consistent magnetization directions. Furthermore, the application of a sparse operator to the gradient’s modulus of the magnetization magnitude helps recover inclined structures. However, the dispersed magnetization directions suggest that we should also constrain the magnetization direction, simultaneously. The inversion of magnetic data measured over the Zaohuohexi iron-polymetallic deposit in Qinghai Province, northwest China, verified the proposed approach’s effectiveness.
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Kushnirenko, A., V. Pryadko, and O. Sinyavsky. "The bioenergetic resonance model at pre-sowing seed crops treatment." Energy and automation, no. 2(54) (June 22, 2021): 97–106. http://dx.doi.org/10.31548/energiya2021.02.097.
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The research is devoted to the study of the behavior of the generalizing magnetization vector in the seeds of agricultural crops under the action of longitudinal constant and transverse alternating magnetic fields by the method of nuclear magnetic resonance. Based on the theoretical studies, the value of the average magnetic susceptibility per unit volume of seed χ and the value of the magnetization vector were determined. For the system of microparticles of cells of plant origin, the average magnetic susceptibility per unit volume of seed is χ = 2.1 · 10-5, and the magnetization vector M=13.125 mA/m at a longitudinal constant magnetic field strength H = 625 A/m. When a weak transverse alternating magnetic field is superimposed on the frequency, the oscillation frequencies of the magnetization vectors M coincide with the field frequency, which is a condition for the occurrence of magnetic resonance. The longitudinal magnetization vector during the transition from the ground state to the excited state (resonant) describes a trajectory in the form of a spiral on the surface of the sphere. A mathematical model for a biological system taking into account the Earth's magnetic field is built. It is established that for the technology of pre-sowing treatment of seeds of agricultural crops, the inductor, which creates a constant magnetic field, must be located so that the vector of the constant magnetic field of the inductor coincides with the vector of the Earth's magnetic field. Keywords: bioenergetic resonance, pre-sowing treatment of crop seeds, direct magnetic field, alternating magnetic field, longitudinal and transverse relaxation
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SPELIOTIS, Dennis, David BONO, and Patrick JUDGE. "VECTOR MAGNETIZATION OF RECORDING MEDIA." Journal of the Magnetics Society of Japan 13, S_1_PMRC_89 (1989): S1_887–892. http://dx.doi.org/10.3379/jmsjmag.13.s1_887.
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Rysak, A., and S. Z. Korczak. "Vector description of nonlinear magnetization." Journal of Magnetism and Magnetic Materials 231, no. 2-3 (2001): 323–30. http://dx.doi.org/10.1016/s0304-8853(01)00199-8.
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Xiao, Xiao, Fabian Müller, Martin Marco Nell, and Kay Hameyer. "Modeling anisotropic magnetic hysteresis properties with vector stop model by using finite element method." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 41, no. 2 (2021): 752–63. http://dx.doi.org/10.1108/compel-06-2021-0213.
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Purpose This paper aims to use a history-dependent vector stop hysteresis model incorporated into a two dimensional finite elements (FE) simulation environment to solve the magnetic field problems in electrical machines. The vector stop hysteresis model is valid for representing the anisotropic magnetization characteristics of electrical steel sheets. Comparisons of the simulated results with measurements show that the model is well appropriate for the simulation of electrical machines with alternating, rotating and harmonic magnetic flux densities. Design/methodology/approach The anisotropy of the permeability of an electrical steel sheet can be represented by integrating anhysteretic surfaces into the elastic element of a vector hysteresis stop model. The parameters of the vector stop hysteresis model were identified by minimizing the errors between the simulated results and measurements. In this paper, a damped Newton method is applied to solve the nonlinear problem, which ensures a robust convergence of the finite elements simulation with vector stop hysteresis model. Findings Analyzing the measurements of the electrical steel sheets sample obtained from a rotational single sheet tester shows the importance to consider the anisotropic and saturation behavior of the material. Comparing the calculated and measured data corroborates the hypothesis that the presented energy-based vector stop hysteresis model is able to represent these magnetic properties appropriately. To ensure a unique way of hysteresis loops during finite elements simulation, the memory of the vector stop hysteresis model from last time step is kept unchanged during the Newton iterations. Originality/value The results of this work demonstrates that the presented vector hysteresis stop model allows simulation of vector hysteresis effects of electrical steel sheets in electrical machines with a limited amount of measurements. The essential properties of the electrical steel sheets, such as phase shifts, the anisotropy of magnetizations and the magnetization characteristics by alternating, rotating, harmonic magnetization types, can be accurately represented.
Dissertations / Theses on the topic "Magnetization vector"
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Richmond, N. C., and L. L. Hood. "A preliminary global map of the vector lunar crustal magnetic field based on Lunar Prospector magnetometer data." AMER GEOPHYSICAL UNION, 2008. http://hdl.handle.net/10150/623323.
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Previous processing of the Lunar Prospector magnetometer (LP-MAG) data has yielded ∼40% coverage of the Moon. Here, new mapping of the low-altitude LP-MAG data is reported with the goal of producing the first global vector map of the lunar crustal magnetic field. By considering all data regardless of the external plasma environment and using less restrictive editing criteria, 2360 partial and complete passes have been identified that can be used to investigate the lunar crustal magnetic anomalies. The cleanest global coverage is provided using 329 low-altitude nightside and terminator passes. An inverse power method has been used to continue the final mapping data to constant altitude. Using the 329 optimal passes, global maps of the lunar crustal magnetic field are constructed at 30 and 40 km. Consistent with previous studies: (1) the largest concentrations of anomalies are mapped antipodal to the Crisium, Serenitatis, Imbrium, and Orientale basins and (2) isolated anomalies at Reiner Gamma, Rima Sirsalis, Descartes, and Airy are mapped. Anomalies previously unmapped by the LP-MAG experiment include (1) isolated anomalies near the craters Abel and Hartwig, (2) weak magnetization within the Nectarian-aged Crisium and Moscoviense basins, and (3) a relatively weak anomaly in an area dominated by crater chains associated with the formation of Nectaris. Future work with the new low-altitude data set is discussed and will include determining whether the lunar anomalies are capable of deflecting the solar wind and investigating directions of magnetization to evaluate a possible former core dynamo.
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Johansson, Tomas. "Active rectification and control of magnetization currents in synchronous generators with rotating exciters : Implementation of the SVPWM algorithm using MOSFET technology." Thesis, Uppsala universitet, Elektricitetslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-257433.
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This thesis aims to design and build a power electronics system for the rectification and control of magnetization currents in synchronous generators with rotating exciters.The rotating exciter provides three-phase AC while the generator rotor needs DC with a high degree of control. The system needs to be able to rectify the three-phase AC to a stable DC without unwanted harmonic content, neither on the DC or the AC side. For control purposes it is also important that the current in the rotor can be changed very swiftly, preferably by several amperes during a single revolution ofthe machine.The system of choice is a synchronous rectifier bridge consisting of six MOSFET switches operated using the Space vector pulse width modulation (SVPWM) algorithm. This method gives a stable and controllable DC voltage while it keeps the harmonic content of the input currents at a minimum. However the DC voltage will always be higher than the peak line-to-line voltage from the exciter. To be able to lower the voltage below this value a Buck-converter is placed after the rectifier bridge.To gain a higher degree of control of the current density in the rotor windings the windings have been subdivided into three parts. To provide individual control of the current in the three rotor parts each part have been outfitted with a Push and Pull H-bridge.The proposed system has been both simulated using MATLAB Simulink and built and tested in the laboratory with satisfactory results.<br>I detta examensarbete presenteras ett kraftelektroniksystem för förbättrad kontroll av magnetiseringsstömmar i vattenkraftsgeneratorer som är utrustade med roterande matare.Generatorer används för att konvertera energi från rörelseenergi till elektrisk energi. Detta görs genom att man utsätter spolar för varierande magnetfält; då induceras spänning i spolarna. I vattenkraftsgeneratorer används oftast stora elektromagneter placerade i en rotor för att skapa dessa magnetfält. För att magnetisera elektromagneterna behövs ström som på något sätt måste överföras mellan den statiska och den roterande sidan i generatorn. Traditionellt görs detta med hjälp av släpringar och kolborstar som genom mekanisk kontakt överför elektriciteten. En roterande matare kan beskrivas som en liten generator som har sina elektriska utgångar på den roterande sidan istället för på den statiska sidan. Genom att placera en roterande matare på samma axel som den stora generatorn kan man istället alstra den elektricitet som behövs för att magnetisera generatorn direkt på den roterande sidan. Däregenom undviks många problem som är associerade med lösningen med släpringar.Den roterande mataren ger dock växelström medan magnetiseringsströmmen måste vara likström. Det är här kraftelektroniken kommer in i bilden. Det finns flera sätt att åstadkomma likriktning av ström. I det här projektet har ett fullständigt aktivt system byggts. Systemet är uppbyggt av transistorer av MOSFET typ och kan kontrolleras trådlöst med hjälp av Bluetoothteknik. Systemet ger full kontroll över strömmar och spänningar både på växelströmssidan och på likströmssidan och ska användas till en testgenerator på avdelningen för ellära vid Uppsala Universitet. Där ska den utökade kontroll som systemet ger förutsättningar till användas för att undersöka hur den här typen av system kan optimera de magnetiska krafterna inuti generatorn. En sådan optimering kan minska vibrationerna i generatorn och därigenom minska slitaget på lager och andra delar i maskinen.
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Markó, Daniel. "Magnetostatics and Dynamics of Ion Irradiated NiFe/Ta Multilayer Films Studied by Vector Network Analyzer Ferromagnetic Resonance." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-64289.
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In the present work, the implications of ion irradiation on the magnetostatic and dynamic properties of soft magnetic Py/Ta (Py = Permalloy: Ni80Fe20) single and multilayer films have been investigated with the main objective of finding a way to determine their saturation magnetization. Both polar magneto-optical Kerr effect (MOKE) and vector network analyzer ferromagnetic resonance (VNA-FMR) measurements have proven to be suitable methods to determine µ0MS, circumventing the problem of the unknown effective magnetic volume that causes conventional techniques such as SQUID or VSM to fail. Provided there is no perpendicular anisotropy contribution in the samples, the saturation magnetization can be determined even in the case of strong interfacial mixing due to an inherently high number of Py/Ta interfaces and/or ion irradiation with high fluences. Another integral part of this work has been to construct a VNA-FMR spectrometer capable of performing both azimuthal and polar angle-dependent measurements using a magnet strong enough to saturate samples containing iron. Starting from scratch, this comprised numerous steps such as developing a suitable coplanar waveguide design, and writing the control, evaluation, and fitting software. With both increasing ion fluence and number of Py/Ta interfaces, a decrease of saturation magnetization has been observed. In the case of the 10×Py samples, an immediate decrease of µ0MS already sets in at small ion fluences. However, for the 1×Py and 5×Py samples, the saturation magnetization remains constant up to a certain ion fluence, but then starts to rapidly decrease. Ne ion irradiation causes a mixing and broadening of the interfaces. Thus, the Py/Ta stacks undergo a transition from being polycrystalline to amorphous at a critical fluence depending on the number of interfaces. The saturation magnetization is found to vanish at a Ta concentration of about 10–15 at.% in the Py layers. The samples possess a small uniaxial anisotropy, which remains virtually unaffected by the ion fluence, but slightly reduces with an increasing number of Py/Ta interfaces. In addition to magnetostatics, the dynamic properties of the samples have been investigated as well. The Gilbert damping parameter α increases with both increasing number of Py/Ta interfaces and higher ion fluences, with the former having a stronger influence. The inhomogeneous linewidth broadening ΔB0 increases as well with increasing number of Py/Ta interfaces, but slightly decreases for higher ion fluences<br>In dieser Dissertation ist der Einfluss von Ionenbestrahlung auf die magnetostatischen und dynamischen Eigenschaften von weichmagnetischen Py/Ta-Einzel- und Multilagen (Py = Permalloy: Ni80Fe20) untersucht worden, wobei das Hauptziel gewesen ist, eine Methode zur Bestimmung der Sättigungsmagnetisierung zu finden. Sowohl polare magneto-optische Kerr-Effektmessungen (MOKE) als auch ferromagnetische Resonanzmessungen mittels eines Vektornetzwerkanalysators (VNA-FMR) haben sich als geeignet erwiesen, um µ0MS zu bestimmen, wobei das Problem des unbekannten effektiven magnetischen Volumens umgangen wird, welches bei der Verwendung von Techniken wie SQUID oder VSM auftreten würde. Unter der Voraussetzung, dass die Proben keinen senkrechten magnetischen Anisotropiebeitrag besitzen, kann die Sättigungsmagnetisierung selbst im Fall starker Grenzflächendurchmischung infolge einer großen Anzahl an Py/Ta-Grenzflächen und/oder Ionenbestrahlung mit hohen Fluenzen bestimmt werden. Ein weiterer wesentlicher Bestandteil dieser Arbeit ist die Konstruktion eines VNA-FMR-Spektrometers gewesen, welches vollautomatisiert ist, polare und azimutale Winkelabhängigkeiten messen kann und einen Magneten besitzt, der Proben, die Eisen beinhalten, sättigen kann. Von Grund auf beginnend umfasste dies zahlreiche Schritte wie z. B. die Entwicklung eines geeigneten koplanaren Wellenleiterdesigns sowie das Schreiben von Steuerungs-, Auswertungs- und Fitprogrammen. Mit steigender Fluenz und Zahl an Py/Ta-Grenzflächen ist eine Abnahme der Sättigungsmagnetisierung beobachtet worden. Im Fall der 10×Py-Proben findet diese bereits bei kleinen Fluenzen statt. Im Gegensatz dazu bleibt µ0MS der 1×Py- und 5×Py-Proben bis zu einer bestimmten Fluenz konstant, bevor sie sich dann umso schneller verringert. Die Bestrahlung mit Ne-Ionen verursacht eine Durchmischung und Verbreiterung der Grenzflächen. Infolgedessen erfahren die Py/Ta-Proben bei einer kritischen Fluenz, die von der Zahl der Grenzflächen abhängig ist, einen Phasenübergang von polykristallin zu amorph. Die Sättigungsmagnetisierung verschwindet ab einer Ta-Konzentration von etwa 10–15 Atom-% in den Py-Schichten. Die Proben besitzen eine kleine uniaxiale Anisotropie, die praktisch unbeeinflusst von der Fluenz ist, sich jedoch mit steigender Zahl an Py/Ta-Grenzflächen leicht verringert. Neben den statischen sind auch die dynamischen magnetischen Eigenschaften der Proben untersucht worden. Der Gilbert-Dämpfungsparameter α erhöht sich sowohl mit steigender Zahl an Py/Ta-Grenzflächen als auch mit höheren Fluenzen, wobei Erstere einen größeren Einfluss hat. Die inhomogene Linienverbreiterung ΔB0 nimmt ebenfalls mit steigender Zahl an Py/Ta-Grenzflächen zu, verringert sich jedoch bei größeren Fluenzen leicht
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Безкоровайный, Владимир Сергеевич. "Повышение помехоустойчивости феррозондовых дефектоскопов к магнитным полям помех". Thesis, Восточноукраинский национальный университет им. В. Даля, 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/18964.
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Диссертация на соискание ученой степени кандидата технических наук по специальности 05.11.13 – Приборы и методы контроля и определение состава веществ. – Национальный технический университет "Харьковский политехнический институт", Харьков, 2015.
В диссертационной работе решается проблема повышения помехоустойчивости феррозондовых дефектоскопов к магнитным полям помех, вызванных конечными размерами контролируемых деталей, их ступенчатыми и галтельными переходами, магнитной неоднородностью ферромагнитного материала. Анализ существующих методов подавления помехи, вызванной сторонним магнитным полем, показал, что основным способом устранения помехи в настоящее время является включение обмоток феррозондов по градиентометрической схеме. Однако этот метод не свободен от недостатков, так его эффективность низка при высоком уровне градиента поля помехи и коэффициент преобразования феррозонда в большей степени зависит от геометрических параметров магнитной системы и расположения полуэлементов феррозонда относительно дефекта. Не свободен от недостатков метод экранирования феррозонда, так как экран значительно увеличивает размеры преобразователя, что затрудняет его использование на ступенчатой поверхности детали. Обзор методов и способов подавления помехи показал, что наиболее эффективным является метод, основанный на использовании двух феррозондов, один из которых является измерительным, а второй – компенсационным. При этом необходимо, чтобы измерительный феррозонд имел достаточную чувствительность, как к магнитному полю дефекта, так и к полю помехи, а компенсационный феррозонд имел высокую чувствительность только к полю помехи и практически не реагировал на поле дефекта. Для теоретического обоснования эффективности предлагаемого метода была разработана математическая модель поля вектора намагниченности, как в области всей детали, так и в локальной области расположения дефекта. Напряженность магнитного поля в сердечниках феррозонда, индуцированного намагниченностью детали и дефекта, рассчитывается путем применения модифицированной теоремы о взаимности К. М. Поливанова. Сердечники измерительного и компенсационного феррозонда являлись полузамкнутыми U-образной формы. Компенсационный феррозонд имеет перемычку непосредственно над дефектом и шунтирует его магнитное поле. Предложен метод расчета магнитного поля помехи индуцированного намагниченной деталью, основанный на решении интегрального уравнения с использованием линейной аппроксимации функции намагничивания, что сокращает порядок системы алгебраических уравнений. Предложен метод расчета коэффициента передачи мостовой электрической схемы феррозонда, при которой уменьшается вдвое число обмоток и создается возможность получения увеличенного его коэффициента передачи за счет явления параметрического резонанса, упрощается балансировка обмоток феррозонда.<br>Thesis for granting the Degree of Candidate of Technical sciences in speciality 05.11.13 – Devices and methods of testing and materials structure determination. – National technical university "Kharkiv Politechnical Institute", Kharkiv, 2015. In the thesis the problem of improving the noise immunity of fluxgate flaw detector to interference’s magnetic fields caused by the finite size of controlled items, their step and fillet connections, the magnetic inhomogeneity of ferromagnetic material has been solved. The method of calculating the magnetic field interference induced by the magnetized part, based on the solution of the integral equation using a linear approximation of the function of the magnetization, which reduces the order of the system of algebraic equations has been proposed. As a transmitter error-correcting ferroprobe flaw is proposed to use a block of the magnetic system consisting of two identical ferroprobes with a U-shaped core. The results of numerical and field experiments have shown that the magnetic flux in the core flux gate with a U-shaped core, with a jumper directly above a defect is 8-12 times smaller than the flow of measurement (main) ferroprobe.
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Безкоровайний, Володимир Сергійович. "Підвищення перешкодостійкості ферозондових дефектоскопів до магнітних полів перешкод". Thesis, Друкарня "Фінвей", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/18960.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 – Прилади і методи контролю та визначення складу речовин. – Національний технічний університет "Харківський політехнічний інститут" Харків, 2015.
У дисертаційній роботі вирішується проблема підвищення перешкодостійкості ферозондових дефектоскопів до магнітних полів перешкод, викликаних кінцевими розмірами контрольованих деталей, їх ступінчастими ї галтельними переходами, магнітною неоднорідністю феромагнітного матеріалу. Запропоновано метод розрахунку магнітного поля перешкоди, індукованого намагніченою деталлю, заснований на вирішенні інтегрального рівняння з використанням лінійної апроксимації функції намагнічування, що скорочує порядок системи алгебраїчних рівнянь. У якості вимірювального перетворювача перешкодостійкого ферозондового дефектоскопа пропонується використовувати блок магнітної системи, що складається з двох ідентичних ферозондів з U-подібними осердям. Результати численних і натурних експериментів показали, що магнітний потік в осерді ферозонду з U-подібним осердям, з перемичкою, розташованою безпосередньо над дефектом, в 8-12 разів менше потоку вимірювального (основного) ферозонду.<br>Thesis for granting the Degree of Candidate of Technical sciences in speciality 05.11.13 – Devices and methods of testing and materials structure determination. – National technical university "Kharkiv Politechnical Institute", Kharkiv, 2015.
In the thesis the problem of improving the noise immunity of fluxgate flaw detector to interference’s magnetic fields caused by the finite size of controlled items, their step and fillet connections, the magnetic inhomogeneity of ferromagnetic material has been solved. The method of calculating the magnetic field interference induced by the magnetized part, based on the solution of the integral equation using a linear approximation of the function of the magnetization, which reduces the order of the system of algebraic equations has been proposed. As a transmitter error-correcting ferroprobe flaw is proposed to use a block of the magnetic system consisting of two identical ferroprobes with a U-shaped core. The results of numerical and field experiments have shown that the magnetic flux in the core flux gate with a U-shaped core, with a jumper directly above a defect is 8-12 times smaller than the flow of measurement (main) ferroprobe.
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Biswas, Saurav. "Non-uniqueness of the modeled magnetization vectors used in determining paleopoles on Mars /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1095426501&sid=26&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Мохсен, Аббасиан. "Коаксиально-линейный двигатель с постоянными магнитами в вибрационной системе погружателя строительных элементов". Thesis, Киевский национальный университет строительства и архитектуры, 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/21242.
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Диссертация на соискание учёной степени кандидата технических наук по специальности 05.09.01 – электрические машины и аппараты. – Национальный технический университет Украины "Харьковский политехнический институт" Харьков, 2016.
Диссертация посвящена вопросам разработки и исследованию особенностей электромагнитных и электромеханических процессов коаксиально-линейных двигателей с аксиальным и радиальным вектором намагничивания постоянных магнитов для привода рабочего органа погружателя. Рассмотрены конструкции коаксиально-линейных двигателей с постоянными магнитами для привода рабочего органа погружателя строительных элементов и разработана математическая модель, а также методы расчета магнитной индукции, электромеханических и частотных характеристик при статическом и динамическом режимах работы вибрационного оборудования на основе коаксиально-линейных двигателей с аксиальным и радиальным вектором намагничивания постоянных магнитов. Предложена модель коаксиально-линейного двигателя с постоянными магнитами с аксиальным и радиальным вектором намагничивания постоянных магнитов в виде электрической схемы замещения и проведён сравнительный анализ векторных диаграмм напряжений и токов, позволяющий характеризовать энергетические параметры и рабочие характеристики при различных частотах напряжения. Разработан и изготовлен экспериментальный стенд для исследования статических и динамических характеристик коаксиально-линейных двигателей с постоянными магнитами. Проведённый анализ электромеханических характеристик коаксиально-линейных двигателей с постоянными магнитами показал, что при одинаковых параметрах жёсткости тяговых и ход-амперных характеристик более эффективным является двигатель с радиальным вектором намагничивания постоянных магнитов. На основе проведенных исследований коаксиально-линейных двигателей с аксиальным и радиальным вектором намагничивания постоянных магнитов с одинаковыми конструктивными параметрами статора и равными по массе магнитами и сравнение их электромагнитных, электромеханических и частотных характеристик, полученных при статическом и динамическом режимах работы двигателей, установлена целесообразность использования коаксиально-линейных двигателей с радиальным вектором намагничивания постоянных магнитов для привода рабочего органа погружателя строительных элементов.<br>The thesis for competition of the academic degree of candidate of technical sciences on the speciality 05.09.01 - electrical machines and apparatus. - The National Technical University "Kharkiv Polytechnic Institute" (NTU "KhPI"), Kharkiv, 2016.
The thesis is devoted to the issues of development and study of the characteristics of magnetic and electromechanical processes in the coaxial linear motors with axial and radial magnetization vector of permanent magnets for drive of the working body of immertor. The construction of coaxial linear motors with permanent magnets for drive of the working body of the immertor of building, models and methods of calculating the values of the parameters of electromagnetic induction, electromechanical and frequency characteristics under static and dynamic modes of vibration equipment with axial and radial magnetization vector of permanent magnets are researched. The experimental stand for removal of static and dynamic characteristics of coaxial linear motors with permanent magnets is developed and manufactured. The analysis of the effectiveness of using the coaxial linear motors with axial and radial magnetization vector of permanent magnets for drive of the working body of the immertor of building elements with the same design parameters of stator and magnets equal in weight during the process of creating drives of vibrators based on comparison, obtained by static and dynamic modes.
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Мохсен, Аббасіан. "Коаксіально-лінійний двигун з постійними магнітами у вібраційній системі занурювача будівельних елементів". Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/21228.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.01 – електричні машини й апарати. – Національний технічний університет України "Харківський політехнічний інститут", Харків, 2016.
Дисертаційна робота присвячена питанням розробки та дослідження особливостей електромагнітних та електромеханічних процесів коаксіально-лінійних двигунів з аксіальним та радіальним вектором намагнічування постійних магнітів для привода робочого органу занурювача. Запропоновані конструкції коаксіально-лінійних двигунів з постійними магнітами для привода робочого органу занурювача будівельних елементів, а також методи розрахунку магнітної індукції, електромеханічних та частотних характеристик при статичному та динамічному режимах роботи вібраційного обладнання на основі коаксіально-лінійних двигунів з постійними магнітами. Розроблені та виготовлені експериментальні стенди для дослідження статичних та динамічних характеристик коаксіально-лінійних двигунів з постійними магнітами. На основі проведеного дослідження коаксіально-лінійних двигунів з аксіальним та радіальним вектором намагнічування постійних магнітів з однаковими конструктивними параметрами статора та рівними за масою магнітами та порівняння їх характеристик, отриманих при статичному та динамічному режимах роботи двигунів, встановлено доцільність використання коаксіально-лінійних двигунів з радіальним вектором намагнічування постійних магнітів для привода робочого органу занурювача будівельних елементів.<br>The thesis for competition of the academic degree of candidate of technical
sciences on the speciality 05.09.01 - electrical machines and apparatus. - The National Technical University "Kharkiv Polytechnic Institute" (NTU "KhPI"), Kharkiv, 2016.
The thesis is devoted to the issues of development and study of the characteristics of magnetic and electromechanical processes in the coaxial linear motors with axial and radial magnetization vector of permanent magnets for drive of the working body of immertor. The construction of coaxial linear motors with permanent magnets for drive of the working body of the immertor of building, models and methods of calculating the values of the parameters of electromagnetic induction, electromechanical and frequency characteristics under static and dynamic modes of vibration equipment with axial and radial magnetization vector of permanent magnets are researched. The experimental stand for removal of static and dynamic characteristics of coaxial linear motors with permanent magnets is developed and manufactured. The analysis of the effectiveness of using the coaxial linear motors with axial and radial magnetization vector of permanent magnets for drive of the working body of the immertor of building elements with the same design parameters of stator and magnets equal in weight during the process of creating drives of vibrators based on comparison, obtained by static and dynamic modes.
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PESCETTO, PAOLO. "Sensorless Commissioning and Control of High Anisotropy Synchronous Motor Drives." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2730183.
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Pugnat, Pierre. "Etude de l'irréversibilité et de l'anisotropie du vecteur aimantation des supraconducteurs à haute température critique." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10049.
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Ce travail propose une etude des proprietes magnetiques anisotropes reversibles et irreversibles de monocristaux supraconducteurs a haute t#c (sht#c), yba#2cu#3o#7 (t#c de 91 k) et la#1#. #8#5sr#0#. #1#5cuo#4 (t#c de 35 k). Les differentes aimantations associees aux variables temperature t, champ magnetique applique h et orientation de ce dernier par rapport au cristal, ont ete etudiees. Une des particularite de ce travail repose sur la mesure simultanee des deux composantes du vecteur aimantation a savoir celles parallele m#l et perpendiculaire m#t au champ applique. Lors de ce type de mesures, la vitesse de rotation de l'echantillon n'est en general pas suffisamment faible pour qu'a chaque instant l'etat d'equilibre thermostatique du reseau de vortex puisse s'etablir. Il en resulte l'apparition sur chacune des composantes d'une contribution hors equilibre a l'aimantation qui developpe une hysteresis rotationnelle. La validite de la decomposition du vecteur aimantation en une contribution reversible et une autre irreversible a ete demontree experimentalement. L'aimantation reversible du cristal yba#2cu#3o#7 a pu etre interpretee avec la theorie de ginzburg-landau anisotrope (gla) pour les temperatures proches de t#c. L'ensemble des parametres phenomenologiques de ce compose (facteur d'anisotropie, champ critique superieur et parametre de ginzburg-landau) a ainsi pu etre obtenu de facon auto-consistante. Des mesures a plus basse temperature semblent mettre en evidence une dependance en champ de l'anisotropie. Pour le cristal la#1#. #8#5sr#0#. #1#5cuo#4, la theorie de gla ne convient pas et l'anisotropie depend, dans cette description, de h et t. Quant a l'etude de la contribution irreversible de l'aimantation transverse des deux cristaux etudies, elle revele l'impact de la structure lamellaire des sht#c sur le piegeage des vortex: la largeur angulaire du pic irreversible de m#t peut etre interpretee en termes d'effet precurseur a la transition de lock-in
Book chapters on the topic "Magnetization vector"
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Ma, Guang, Chengxu He, Ling Cheng, Mengxue Lu, and Nana Duan. "Proposal and Validation of Vector Hysteresis Operator Based on Microscopic Magnetization Mechanism." In Lecture Notes in Electrical Engineering. Springer Nature Singapore, 2024. https://doi.org/10.1007/978-981-97-8812-5_15.
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Kuroda, Jumpei, Kaito Kimura, Ryutaro Ono, et al. "Study on Linear Actuators for Intake and Exhaust Systems of Internal Combustion Engines (Analytical Consideration of Thrust Characteristics by Permanent Magnet Array)." In Lecture Notes in Mechanical Engineering. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-70392-8_3.
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AbstractTo enhance internal combustion engine performance, this study focuses on developing an electric valve drive system utilizing linear actuators for intake and exhaust valve control. The linear actuator, comprising a movable coil and a fixed permanent magnet, operates based on the principle of the Lorentz force. Unlike traditional magnetic circuits, this actuator employs five permanent magnets with different magnetization directions to concentrate the flux on the coil. In this study, multiple models with varying ratios of these permanent magnets were created and analyzed using finite element analysis conducted with the JMAG software to investigate the thrust characteristics during the reciprocating motion of the actuator. The vector plot of the magnetic flux density shows that the magnetic circuit is predominantly composed of permanent magnets. The average thrust at a 10 mm displacement was approximately 107 N in the largest model. Future studies will aim to design actuators with increased thrust capabilities.
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Schweiger, Arthur, and Gunnar Jeschke. "Classical description." In Principles of Pulse Electron Paramagnetic Resonance. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198506348.003.0002.
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Abstract In this chapter we introduce the magnetization vector picture for the description of pulse EPR experiments. The motion of magnetization vectors under the influence of static and oscillatory magnetic fields is described by the classical Bloch equations, which also consider relaxation in a phenomenological way. The behaviour of the macroscopic electron spin magnetization during and after resonant and off-resonant m.w. pulses is examined. This provides the basis for a discussion of the free induction decay FID after a single m.w. pulse.
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Dove, Martin T. "Physical Properties." In Structure and Dynamics: An Atomic View of Materials. Oxford University PressOxford, 2003. http://dx.doi.org/10.1093/oso/9780198506775.003.0007.
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Abstract We are used to thinking about the physical properties of materials in terms of scalar quantities, such as volume and energy.These will vary as the external conditions are changed. Simple examples are the coefficient of volumeexpansion,or the compressibility, We also understand that some properties can have a vector form. For example,the magnetization of a ferromagnetic material is a vector quantity. Moreover,some external stimuli have the nature as vectors and give a response that can be described as a vector.
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Coey, J. M. D. "Introduction." In Rare-earth Iron Permanent Magnets. Oxford University PressOxford, 1996. http://dx.doi.org/10.1093/oso/9780198517924.003.0001.
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Abstract The magnetization of a piece of ferromagnetic material has its origin in the spin and orbital magnetic moments of the atomic electrons. These moments arise from the angular momentum of the electrons. Nuclear magnetism is negligible by comparison. Summing the elementary contributions in a volume that is large on the atomic scale, one defines a local magnetization vector, M, that represents the magnetic moment per unit volume. In general, M is not uniform throughout a sample of macroscopic dimensions, but when the sum is carried out within a domain, the magnitude of M, known as the spontaneous magnetization Ms, is uniform; the direction of magnetization varies from domain to domain and typically lies along a crystallographic axis.
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Iggo, Jonathan A., and Konstantin V. Luzyanin. "Experimental methods: pulses, the vector model, and relaxation." In NMR Spectroscopy in Inorganic Chemistry. Oxford University Press, 2020. http://dx.doi.org/10.1093/hesc/9780198794851.003.0004.
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This chapter examines how an NMR spectrum is recorded and how we can tailor the spectroscopic experiment to maximize the information we are interested in. It begins by looking at how the NMR signal is created, and NMR spectra acquired. Traditionally, this was done using the continuous wave method; modern spectrometers use the pulse Fourier transform method. Meanwhile, the vector model provides a simple means to visualize the effect of an excitation pulse on the NMR magnetization and the evolution of the magnetization vector in the rotating frame and can be used to understand simple pulse sequences. Relaxation is an important consideration when using excitation pulses and sample averaging, since we must allow the system to return to equilibrium before starting the excitation sequence again. Relaxation can also provide valuable structural information and dynamic information about a sample that is not accessible through analysis of the chemical shifts and couplings.
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Atkins, Peter, Julio de Paula, and Ronald Friedman. "Pulse techniques in NMR." In Physical Chemistry: Quanta, Matter, and Change. Oxford University Press, 2013. http://dx.doi.org/10.1093/hesc/9780199609819.003.0065.
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Contents The magnetization vector 476 The effect of the radiofrequency field 477 Brief illustration 49.1: Radiofrequency pulses 478 Time- and frequency-domain signals 478 Brief illustration 49.2: Fourier analysis 479 Spin relaxation 479 Brief illustration 49.3: Inhomogeneous broadening 481 The nuclear...
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Aharoni, Amikam. "Introduction." In Introduction to the Theory of Ferromagnetism. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198508083.003.0001.
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Abstract It is known from experiment that every material which is put in a magnetic field, H, acquires a magnetic moment. The dipole moment per unit volume is defined as the magnetization, and will be denoted here by the vector M.
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Schweiger, Arthur, and Gunnar Jeschke. "Desity operators and their evolution." In Principles of Pulse Electron Paramagnetic Resonance. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198506348.003.0004.
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Abstract In this chapter we introduce the quantum mechanical description of the state of spin ensembles and of their time evolution The relation between the density operator and the magnetization vector of ensembles of isolated spins S = 1/2 is explained. We derive the equation of motion of the density operator from the Schrodinger equation and discuss how the evolution of spin systems during pulse EPR experiments can be mathematically described.
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Psuj Grzegorz. "Fusion of Multiple Parameters of Magnetic Testing Results for Damage Assessment of Loaded Steel Structures." In Studies in Applied Electromagnetics and Mechanics. IOS Press, 2015. https://doi.org/10.3233/978-1-61499-509-8-192.
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In this paper, in order to increase the reliability of damage assessment in steel elements, a multiple parameters data fusion approach was performed. Results of examination of stress loaded steel samples obtained by Barkhausen noise and AC magnetization method was utilized. Several parameters of measured signals were considered in order to define feature vector corresponding to the damage state of the material. Finally, the collected parameters sets were supplied to the data processing and fusion procedures allowing damage state assessment.
Conference papers on the topic "Magnetization vector"
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Aisengart, T., J. G. Pereira, M. Rech, R. D. Barbosa, C. Porto, and J. L. Ando. "Self-Organizing Maps applied to Magnetization Vector Inversion." In 15th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 31 July-3 August 2017. Brazilian Geophysical Society, 2017. http://dx.doi.org/10.1190/sbgf2017-106.
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Kanda, N., T. Higchi, H. Shimizu, K. Konishi, K. Yoshioka, and M. Kuwata-Gonokami. "Optical manipulation of magnetization vector in multidimensional space." In Nonlinear Optics: Materials, Fundamentals and Applications. OSA, 2011. http://dx.doi.org/10.1364/nlo.2011.nmd7.
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Queitsch, M., M. Schiffler, R. Stolz, and N. Kukowski. "A Staggered Approach to Extract Remanent Magnetization from Magnetization Vector Inversions Using an Active Source." In 80th EAGE Conference and Exhibition 2018. EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201800952.
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Patrakov, V., and S. Rukin. "Computer simulation of multi-gigawatt magnetic compression lines." In 8th International Congress on Energy Fluxes and Radiation Effects. Crossref, 2022. http://dx.doi.org/10.56761/efre2022.s6-p-017001.
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Magnetic compression lines (MCL) are novel solid-state devices for multi-gigawatt sub-nanosecond and picosecond pulse amplification. Their operation is based on the interaction of magnetic field created by a powerful nanosecond or sub-nanosecond pulse with the magnetization vector in a ferrite medium. In this study a numerical model of an MCL was created, based on Maxwell’s equations and Landau-Lifshitz-Gilbert equation for magnetization dynamics. The equation system is solved using COMSOL Multiphysics simulation software. The model shows good agreement with the experimental data. Using the created model, the process of power amplification in MCL was analyzed in terms of magnetic field and magnetization vectors. Based on this analysis, the mechanism of unipolar pulse amplification has been proposed.
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Li, Z., C. Yao, and Y. Zheng. "2D Sparse Magnetization Vector Inversion Based On L1-Minimization." In 79th EAGE Conference and Exhibition 2017. EAGE Publications BV, 2017. http://dx.doi.org/10.3997/2214-4609.201701083.
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Couto, Marco Antonio, Telma Aisengart, Diego Barbosa, et al. "Magnetization Vector Inversion Application in Quadrilatero Ferrifero Region, MG, Brazil." In 15th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 31 July-3 August 2017. Brazilian Geophysical Society, 2017. http://dx.doi.org/10.1190/sbgf2017-103.
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Li*, Yaoguo, and Jiajia Sun. "Total magnetization vector inversion using guided fuzzy c-means clustering." In SEG Technical Program Expanded Abstracts 2014. Society of Exploration Geophysicists, 2014. http://dx.doi.org/10.1190/segam2014-1041.1.
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Xiao, Xiao, Fabian Muller, Gregor Bavendiek, and Kay Hameyer. "Vector hysteresis models in comparison to the anhysteretic magnetization model." In 2019 19th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering (ISEF). IEEE, 2019. http://dx.doi.org/10.1109/isef45929.2019.9096924.
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Ou, Yang, and Jie Feng. "Joint magnetization vector inversion of surface and borehole magnetic data." In International Workshop and Gravity, Electrical & Magnetic Methods and their Applications, Chenghu, China, 19-22 April 2015. Society of Exploration Geophysicists and and Chinese Geophysical Society, 2015. http://dx.doi.org/10.1190/gem2015-019.
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Aisengart, Telma. "Qualitative and Quantitative Magnetization Vector Inversion applied to the Pirapora Anomaly." In 14th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 3-6 August 2015. Brazilian Geophysical Society, 2015. http://dx.doi.org/10.1190/sbgf2015-094.
Full textReports on the topic "Magnetization vector"
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Kaski, K., J. Smith, V. L. Tschirhart, and G. Heggie. 3D magnetic-susceptibility and magnetization-vector inversions of remanently magnetized conduit-type Ni deposits: a case study from the Thunder Bay North intrusive complex, Ontario. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/pkwpmf1tju.
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Les données aéromagnétiques constituent un outil important et instructif pour la délimitation des gisements magmatiques de sulfures Ni-Cu-ÉGP, car elles fournissent des informations essentielles pour l'estimation de la taille et de la profondeur d'une cible. Les roches magmatiques mafiques conservent généralement une importante magnétisation rémanente, ce qui constitue un élément important à prendre en compte lors de l'interprétation et de la modélisation d'une cible. Des inversions de susceptibilité magnétique sans contrainte, dérivées des données TMI de Clean Air Metals, sont présentées pour le complexe intrusif de Thunder Bay North, en Ontario, afin d'étudier la géométrie 3D et l'extension des intrusions mafiques-ultramafiques minéralisées en Ni-Cu-ÉGP. Des inversions de vecteurs d'aimantation sont également présentées, fournissant des informations complémentaires sur l'étendue et l'ampleur de l'aimantation rémanente. Dans le complexe intrusif de Thunder Bay North, les intrusions Escape et Current sont modélisées comme des intrusions de type conduit étroit dont la morphologie devient tabulaire en plongée. Bien que la modélisation soit cohérente avec le forage de l'intrusion Current, les résultats indiquent la présence d'un corps à susceptibilité magnétique plus faible en aval-pendage de l'étendue connue de l'intrusion Escape. La susceptibilité magnétique des deux intrusions est notablement plus faible lorsqu'elles sont recoupées par la faille bordière de la sous-province de Quetico, d'orientation W-E. La magnétisation rémanente semble être plus importante que celle de l'intrusion de Current. L'aimantation rémanente semble être maintenue localement immédiatement au sud de la faille Quetico, ce qui correspond aux fortes anomalies négatives de surface des deux intrusions. Dans ces régions, l'aimantation est fortement anti-corrélée avec le champ inducteur.