Academic literature on the topic 'Magnetization vector field'
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Journal articles on the topic "Magnetization vector field"
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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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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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IVEZIĆ, TOMISLAV. "THE CONSTITUTIVE RELATIONS AND THE MAGNETOELECTRIC EFFECT FOR MOVING MEDIA." International Journal of Modern Physics B 26, no. 08 (2012): 1250040. http://dx.doi.org/10.1142/s0217979212500403.
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In this paper the constitutive relations for moving media with homogeneous and isotropic electric and magnetic properties are presented as the connections between the generalized magnetization–polarization bivector [Formula: see text] and the electromagnetic field F. Using the decompositions of F and [Formula: see text], it is shown how the polarization vector P(x) and the magnetization vector M(x) depend on E, B and two different velocity vectors, u — the bulk velocity vector of the medium, and v — the velocity vector of the observers who measure E and B fields. These constitutive relations with four-dimensional geometric quantities, which correctly transform under the Lorentz transformations (LT), are compared with Minkowski's constitutive relations with the 3-vectors and several essential differences are pointed out. They are caused by the fact that, contrary to the general opinion, the usual transformations of the 3-vectors E, B, P, M, etc. are not the LT. The physical explanation is presented for the existence of the magnetoelectric effect in moving media that essentially differs from the traditional one.
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Baratchart, Laurent, Cristóbal Villalobos Guillén, and Douglas P. Hardin. "Inverse potential problems in divergence form for measures in the plane." ESAIM: Control, Optimisation and Calculus of Variations 27 (2021): 87. http://dx.doi.org/10.1051/cocv/2021082.
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We study inverse potential problems with source term the divergence of some unknown (ℝ3-valued) measure supported in a plane; e.g., inverse magnetization problems for thin plates. We investigate methods for recovering a magnetization μ by penalizing the measure-theoretic total variation norm ∥μ∥TV , and appealing to the decomposition of divergence-free measures in the plane as superpositions of unit tangent vector fields on rectifiable Jordan curves. In particular, we prove for magnetizations supported in a plane that TV -regularization schemes always have a unique minimizer, even in the presence of noise. It is further shown that TV -norm minimization (among magnetizations generating the same field) uniquely recovers planar magnetizations in the following two cases: (i) when the magnetization is carried by a collection of sufficiently separated line segments and a set that is purely 1-unrectifiable; (ii) when a superset of the support is tree-like. We note that such magnetizations can be recovered via TV -regularization schemes in the zero noise limit by taking the regularization parameter to zero. This suggests definitions of sparsity in the present infinite dimensional context, that generate results akin to compressed sensing.
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Antonov, L. I., A. S. Zhukarev, P. A. Polyakov, and D. G. Skachkov. "Magnetization vector field in a uniaxial ferromagnetic film." Technical Physics 49, no. 3 (2004): 363–64. http://dx.doi.org/10.1134/1.1688427.
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Rivkin, Kirill, and Michael Montemorra. "Spin wave computing using pre-recorded magnetization patterns." Journal of Applied Physics 132, no. 15 (2022): 153902. http://dx.doi.org/10.1063/5.0096192.
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We propose a novel type of spin wave computing device, based on a bilayer structure that includes a “bias layer” made from a hard magnetic material and a “propagation layer” made from a magnetic material with low damping, for example, yttrium garnet or permalloy. The bias layer maintains a stable pre-recorded magnetization pattern, which generates a bias field with a desired spatial dependence, which in turn sets the equilibrium magnetization inside the propagation layer. When an external source applies an RF field to the propagation layer, excited spin waves scatter on the magnetization's inhomogeneities resulting in complex interference behavior. This scattering interference can be utilized to perform a variety of mathematical operations including Vector-Matrix multiplication. The spatial dependence of such magnetization patterns can be estimated via perturbation theory.
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Gouda, Kaiki, and Takashi Nishioka. "Angular-field magnetic phase diagram of b-plane at 4 K of YAlGe-type TbAlGe with zigzag-chain." Journal of Physics: Conference Series 2164, no. 1 (2022): 012072. http://dx.doi.org/10.1088/1742-6596/2164/1/012072.
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Abstract Orthorhombic YAlGe-type TbAlGe is expected to have an interesting magnetic anisotropy due to zigzag chains of the Tb ions. We have grown the single crystal for the first time and measured the AC magnetic susceptibility and specific heat from 1.3 K to 60 K, and the vector magnetization for the b-plane up to 7 T at 4 K. The specific heat and AC magnetic susceptibility indicate that there are two antiferromagnetic transitions at T N1 = 38 K and TN2 = 7.6 K, where the transition at T N2 is first-order like. The magnetization curve at 4 K for the a-axis shows a large hysteresis, and metamagnetic transition appears at H 1 = 1.6 T in the field increasing process, and another metamagnetic transition at H2 = 3.5 T in addition to H 1 in the decreasing field process. The magnetization curves of the b- and c-axis are linear up to 7 T. The measurement of vector magnetization at 4 K reflects the hysteresis of the magnetization curve, and there is a large hysteresis. From this vector magnetization measurement, we have made the angular magnetic field phase diagram at 4 K for the b-plane. In this phase diagram, there are phase lines that cannot be obtained by ordinary magnetization measurement.
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Khalilov, V. R., Choon-Lin Ho, and Chi Yang. "Condensation and Magnetization of Charged Vector Boson Gas." Modern Physics Letters A 12, no. 27 (1997): 1973–81. http://dx.doi.org/10.1142/s0217732397002028.
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The magnetic properties of charged vector boson gas are studied in the very weak, and very strong (near critical value) external magnetic field limits. When the density of the vector boson gas is low, or when the external field is strong, no true Bose–Einstein condensation occurs, though significant amount of bosons will accumulate in the ground state. The gas is ferromagnetic in nature at low temperature. However, Bose–Einstein condensation of vector bosons (scalar bosons as well) is likely to occur in the presence of a uniform weak magnetic field when the gas density is sufficiently high. A transitional density depending on the magnetic field seems to exist below which the vector boson gas changes its property with respect to the Bose–Einstein condensation in a uniform magnetic field.
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ROJAS, H. PÉREZ, and E. RODRÍGUEZ QUERTS. "MAGNETIC FIELDS IN QUANTUM DEGENERATE SYSTEMS AND IN VACUUM." International Journal of Modern Physics D 16, no. 02n03 (2007): 165–73. http://dx.doi.org/10.1142/s0218271807009917.
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We consider self-magnetization of charged and neutral vector bosons bearing a magnetic moment in a gas and in vacuum. For charged vector bosons (W bosons) a divergence of the magnetization in both the medium and the electroweak vacuum occurs for the critical field [Formula: see text]. For B > Bwc the system is unstable. This behavior suggests the occurrence of a phase transition at B = Bc, where the field is self-consistently maintained. This mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the ground state behavior for [Formula: see text] have a similar behavior. The magnetization in the medium is associated to a Bose–Einstein condensate and we conjecture a similar condensate occurs also in the case of vacuum. The model is applied to virtual electron-positron pairs bosonization in a magnetic field [Formula: see text], where me is the electron mass. This would lead also to vacuum self-magnetization in QED, where in both cases the symmetry breaking is due to a condensate of quasi-massless particles.
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Angulo, Gretel Quintero, Aurora Pérez Martínez, and Hugo Pérez Rojas. "Condensation of Neutral Vector Bosons with Magnetic Moment." International Journal of Modern Physics: Conference Series 45 (January 2017): 1760047. http://dx.doi.org/10.1142/s2010194517600473.
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We study the equation of motion of neutral vector bosons bearing a magnetic moment (MM). The effective rest mass of vector bosons is a decreasing function of the magnetic field intensity. Consequently a diffuse condensation of the bosons appears below a critical value of the field. For typical values of densities and magnetic fields the magnetization is positive and the neutral boson system can maintain a magnetic field self-consistently. A discussion of the relevance in astrophysics is presented.
Dissertations / Theses on the topic "Magnetization vector field"
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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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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.
Book chapters on the topic "Magnetization vector field"
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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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Maggiore, Michele. "Electromagnetic fields in material media." In A Modern Introduction to Classical Electrodynamics. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/oso/9780192867421.003.0013.
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Abstract In this chapter we begin our study of electromagnetic fields in materials. We first show how the fundamental Maxwell equations give rise to ‘smoothed’ Maxwell equations valid at macroscopic scales. To use these equations, however, we must have a model for the macroscopic charge and current densities. We introduce the polarization vector field P and the electric displacement vector field D for a dielectric and the magnetization M and the H field for magnetic material, and we write the Maxwell equations in terms of these quantities. The complexity of the materials is then described phenomenologically by ‘constitutive relations’ involving these macroscopic quantities. We introduce the permittivity and the dielectric constant of the dielectric, and the magnetic susceptibility and magnetic permeability of magnetic matter, that allows us to distinguish between paramagnetic and diamagnetic materials. We study energy conservation and the Poynting theorem in material bodies.
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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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Freeman, R. "Spin choreography." In Pulsed Magnetic Resonance: NMR, ESR, and Optics. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780198539629.003.0010.
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Abstract Very soon after the initial discovery of nuclear magnetic resonance, E. L. Hahn performed an experiment that, in conceptual originality and elegance, transcended all that had preceded it-the spin echo experiment [1]. Here was an idea to inspire the young scientists reading about NMR for the first time. Not only could oneworkwith these strange new entities called spins, but alsomanipulatethem like a conjuror with a pack of cards. In its original form, experiment was conceptually easier to follow, resembling the opening and closing of a ‘fan’ of vectors confined to the transverse(x-y)plane of the rotating frame. Note that the description of the conventional continuous wave NMR experiments of the time scarcely required this level of sophistication, relying on the steady state solutions of the Bloch equations. To understand spin echoes, one was forced to come to grips with homogeneous and inhomogeneous line broadening, transformation into the rotating frame of reference, and the concept of ‘spin isochromats’. This was a term coined by Abragam [3]. The sample is considered to be made up of a mosaic of volume elements, each small enough that the variation of the applied field intensity across that element could be neglected, but with neighbouring elements in slightly different applied fields due to the spatial inhomogeneity. Each element has a nuclear magnetization with a characteristic precession frequency; this is an isochromat. The total sample magnetization is the resultant of all these isochromatic magnetization vectors. Because the isochromats have different intrinsic frequencies this resultant can change as individual isochromats fan out or come back into alignment. This has proved a valuable idea for describing spin echo experiments.
Conference papers on the topic "Magnetization vector field"
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Matsuo, Tetsuji, Yasuhito Takahashi, and Koji Fujiwara. "An Anisotropic Vector Play Model and Its Application to Magnetization Analysis." In 2022 IEEE 20th Biennial Conference on Electromagnetic Field Computation (CEFC). IEEE, 2022. http://dx.doi.org/10.1109/cefc55061.2022.9940751.
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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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LaMaster, Doug, Heidi Feigenbaum, Isaac Nelson, and Constantin Ciocanel. "A Memory Variable Approach to Modeling the Magneto-Mechanical Behavior of Magnetic Shape Memory Alloys." In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3036.
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Magnetic shape memory alloys (MSMAs) have attracted interest because of their considerable recoverable strain (up to 10%) and fast response time (1 kilohertz or higher). MSMAs are comprised of martensitic variants that have tetragonal unit cells and a magnetization vector that is innately aligned with the short side of the unit cell. These variants rotate either to align the magnetization vector with an applied magnetic field or to align the short side of the unit cell with an applied compressive stress. This reorientation leads to a mechanical strain and an overall change in the material’s magnetization, allowing MSMAs to be used as actuators, sensors, and power harvesters. This paper builds upon the work of Kiefer and Lagoudas [4,5] as well as improvements proposed by LaMaster et al. [1] to present a thermodynamic based model to predict the response of an MSMA to axial mechanical loading and transverse magnetic loading. This work is unique, however, in its use of a memory variable, which references the last stable configuration. This is similar to the approach used by Saint-Sulpice [2] in modeling SMA wires. The resulting model has zero driving force for reorientation of variants at the beginning of any load and again when the load is removed. Thus the model predicts what is seen physically, that the material is stable when no magneto-mechanical load is present. Furthermore, this model is more physical and less empirical than others in the literature, having only 2 material parameters associated with the stress-strain or stress-field response. In addition, this model includes evolution rules for the magnetic domain volume fractions and the angle of rotation of the magnetization vectors based on thermodynamic requirements. The resulting model is calibrated and predictions are compared with both the more established Keifer and Lagoudas model as well as experimental data. Results show decent correlation with experiments. The model can be further improved by calibrating the demagnetization factor to experimentally measured changes in magnetic field.
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Harutyunyan, S., D. J. Hasanyan, and R. B. Davis. "Magnetoelastic Interactions at the Planar Interface of Two Ferromagnetic Solids: A Theoretical Study." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39444.
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A model for the phenomena in which magnetic waves excite elastic waves and vice versa, is formulated and used to explore magnetic and anti-plane elastic interactions in piecewise homogeneous ferromagnetic media. The magnetization vectors in each medium are perpendicular to the wave propagation direction. The space is in an external homogeneous magnetic field, the direction of which coincides with direction of the initial magnetization vector. A joint contact on the interface of two ferromagnetic semi-spaces is considered. The existence of new type of waves is shown. These waves are localized on the interface of two ferromagnetic media and accompany to the reflection and transmission waves. These types of waves named as an accompanying surface magnetoelastic (ASM) waves. An analytical expression for the coefficients of reflection, transmission, and accompanying surface magnetoelastic waves is derived. Coefficients of mentioned waves are strongly dependent on applied magnetic field, material properties of each medium as well as the frequency and the angle of an incident elastic wave. Conclusions and directions for the design of magnetoelastic devises are outlined.
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Anand, Nadish, and Richard Gould. "Study of Enhanced Self Mixing in Ferrofluid Flow in an Elbow Channel Under the Influence of Non-Uniform Magnetic Field." In ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ajkfluids2019-5546.
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Abstract This paper investigates numerically the various parameters dictating the vortical (self)-mixing induced by a non-uniform magnetic field in a ferrofluid flow in an elbow channel. The elbow bend region of the channel has two current carrying conductors placed symmetrically and parametrically from the channel and are used to generate a non-uniform magnetic field. The ferrofluid is assumed to be pre-magnetized, isothermal and electrically non-conductive as it enters the channel and has a prescribed inlet magnetization and temperature. The mixing efficiency is characterized by introducing different mixing scalars based on velocity of the fluid and are compared in order to determine the overall suitability of each scalar to quantify the flow vortical (self)-mixing. Parametric studies were performed by varying parameters influencing the magnetic field and the initial flow field. This resulted in variations in non-dimensional groups which control different aspects of the flow and helped establish their relationship with mixing efficiency. It was found that at higher Reynolds numbers the flow mixing induced by the lateral gradient in the Kelvin Body Force (KBF) dissipates and higher electrical inputs are required to sustain mixing in the flow. The effects of mixing enhancement on the pressure gradient across the channel was also established, along with the introduction of an enhanced viscosity term which is due to the non-collinearity of the magnetization vector and the magnetic field vector.
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Vervaeke, K. "P5.1 - Inspection of Magnetization Vector and Magnetic Field Distribution of Uniaxial and Multipole Sensor Magnets Using Fast High Resolution MagCam Magnetic Field Mapping and Analysis." In SENSOR+TEST Conferences 2011. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2011. http://dx.doi.org/10.5162/sensor11/sp5.1.
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Mitrović, Nebojša, Jelena Orelj, Borivoje Nedeljković, Radoslav Surla, and Vladimir Pavlović. "Structural and magnetic properties of CoFeSiB amorphous wire GMI element." In 11th International Scientific Conference on Defensive Technologies - OTEX 2024. Military Technical Institute, Belgrade, 2024. http://dx.doi.org/10.5937/oteh24111m.
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In this study, the amorphous soft magnetic Co68.15Fe4.35Si12.5B15 wires prepared by the conventional inrotating water melt-spinning technique were investigated. The XRD pattern of the as-cast wire sample exhibits a very weak diffusive peak that reveals the amorphous structure. The DTA thermogram shows one exothermic process, which results from crystallization with a peak temperature of 566 °C. The XRD pattern of the sample annealed at 700 °C shows the presence of two diffraction peaks: the first could be ascribed to the crystal phase e-CoSi (structure of P2 order), and the second could belong to crystal phases Co2B and e-CoSi (P2 order). The giant magnetoimpedance (GMI) frequency behavior (ranging from 50 Hz to 5 MHz) was monitored as a function of an external dc magnetic field applied parallel to the wire sample. The critical frequency of about 5 kHz - 7 kHz was observed with the initial increase of MI. In the medium frequency range (which usually starts at about 1 MHz) the skin effect and the magnetization vector rotation mechanism are dominant in the process of circular magnetization (the movement of the magnetic domain walls is blocked). Therefore, the shape of dependence of the MI-ratio on the external DC magnetic field changes significantly and the appearance of a peak is recorded. The attained peak value of the impedance modulus of about 35 Ω was registered at the highest frequency of 5 MHz. The maximum GMI ratio of 334% was recorded at a frequency of 0.95 MHz (@ 7.72 kA/m).
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Harutyunyan, Satenik, and Robert B. Davis. "Magnon-Phonon Interactions in a Ferromagnetic Media: Reflection and Refraction of Magneto-Elastic Waves." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11879.
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Reflection and refraction of magneto-elastic waves at the interface of two ferromagnetic half-spaces is considered. The space is in an external homogeneous magnetic field, the direction of which coincides with direction of the initial magnetization vector. A slipping contact on the interface of two ferromagnetic semi-spaces is considered. The existence of new type of waves is shown. These waves are localized on the interface of two ferromagnetic media and accompany the reflection and transmission waves and exist because of incident waves on the interface of two magneto-elastic media, and magneto-elastic properties of the media. These types of waves named as an accompanying surface magnetoelastic (ASM) waves. An analytical expression for the magnitudes of reflection, refraction, and ASM waves are derived. Coefficients of mentioned waves are strongly dependent on the applied magnetic field, material properties of each medium, as well as on frequency and the angle of an incident elastic wave. It has been shown that an applied magnetic field can totally eliminate or strengthen transmission and reflection waves and can be a control parameter for exchanging energies between these waves. Also, by eliminating transmission and reflection waves the magnetic field is able to control the ASM wave magnitudes. A new wave filtration mechanism can be drawn from these effects.
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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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Nelson, Isaac, Constantin Ciocanel, Doug LaMaster, and Heidi Feigenbaum. "The Impact of Boundary Conditions on the Response of NiMnGa Samples in Actuation and Power Harvesting Applications." In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3234.
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Magnetic shape memory alloys (MSMAs) are materials that can display up to 10% recoverable strain in response to the application of a magnetic field or compressive mechanical stress. The magnetomechanical response of the material makes MSMAs suitable for applications such as actuation, sensing, and power harvesting. While the magnetomechanical response of the material has been extensively investigated to date, there is no report in the literature on the effect of the boundary conditions (BCs) on its response. The response of MSMAs is primarily driven by the reorientation of internal martensite variants, in conjunction with rotation of magnetization vectors, and domain wall motion. During the reorientation process a change in material’s magnetization occurs. For sensing and power harvesting applications, a pick-up coil may be used to convert this change in magnetization into an electric potential/voltage. To date, it has been confirmed experimentally that, according to Faraday’s law of induction, the magnitude of the output voltage depends on the number of turns of the pick-up coil, the amplitude of the reorientation strain, the magnitude and direction of the biased magnetic field, and the frequency at which the reorientation occurs. However, to our knowledge, no study has been carried out to investigate the effect of the BCs on the voltage output. This paper examines the effect of the BCs on the material’s magnetomechanical response, as well as on the corresponding voltage output. Three BCs are considered in the performed experiments: i) simply supported, ii) clamped, and iii) mixed (i.e. one end clamped and one end guided). The difference observed in the magnetomechanical response of the material, between the tested BCs, is attributed to the local effects caused by the grips (particularly the clamped and mixed conditions) and by the rotation of the specimen within the grips (in the simply supported condition). The latter is facilitated by the difference between the cross section of the specimen and the cross section of the cavity receiving the sample and by the larger effective length of the specimen in this case.