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Dissertations / Theses on the topic 'Constant magnet'

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Published: 30 May 2022
Last updated: 31 July 2025

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1

Alsawalhi, Jamal Yousuf. "An asymmetric salient permanent magnet synchronous machine for wide constant power speed range applications." Thesis, Purdue University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3686817.

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<p>This work introduces a novel permanent-magnet synchronous machine (PMSM) architecture that employs rotational asymmetry to increase the torque density output in constant power variable speed applications. A population based multi-objective design optimization algorithm is used to design and analyze the new machine topology. A number of design studies are presented to show that the proposed machine structure outperforms a conventional PMSM machine. Validation of the analytical machine design model using a three dimensional finite element analyses is performed and the results are presented. F
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2

De, Kock Hugo Werner. "Dynamic control of the permanent magnet assisted reluctance synchronous machine with constant current angle." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/2062.

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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006.<br>This thesis is about the dynamic control of a permanent magnet assisted reluctance synchronous machine (PMA RSM). The PMA RSM in this thesis is a 110 kW traction machine and is ideal for the use in electrical rail vehicles. An application of the dynamic control of the PMA RSM in electrical rail vehicles is to reduce wheel slip. The mathematical model of the PMA RSM is derived and explained in physical terms. Two methods of current control for the PMA RSM are investigated, namely constant field cu
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3

Rim, Geun-hie. "Variable speed constant frequency power conversion with permanent magnet synchronous and switched reluctance generators." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/40015.

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4

Chin, Yung-Kang. "A permanent magnet synchronous motor for an electric vehicle - design analysis." Licentiate thesis, KTH, Electrical Systems, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1763.

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<p>This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3.</p><p>A design approach based on the CPSR contour plot in aninterior permane
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5

Rim, Geun-hie. "Modeling, analysis and experimental verification of variable-speed constant-frequency power conversion scheme with a permanent magnet synchronous generator." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-06062008-163303/.

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6

Miao, Dongmin. "Voltage Stabilization Control of Wide-Speed-Range Permanent-Magnet Synchronous Generator Systems." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/246410.

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DC power systems have a constant DC-link voltage, as well as the advantages such as high stability, high efficiency, small size and light weight; therefore, they are widely used in stand-alone power systems, e.g. the power systems in aircrafts and automobiles, isolated wind power generation systems, etc. Permanent-Magnet Synchronous Generators (PMSGs) possess the advantages including high power density, high efficiency, and high control precision, and have obtained great attention and have been widely used in military, inductry, and daily life. Pulse Width Modulation (PWM) rectifier has been o
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7

Любарський, Борис Григорович. "Моделювання та розробка комбінованого збудження зварювальних генераторів постійного струму з метою поліпшення їх техніко-економічних показників". Thesis, НТУ "ХПІ", 2001. http://repository.kpi.kharkov.ua/handle/KhPI-Press/5320.

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Дисертація присвячена питанням підвищення ККД зварювальних генераторів постійного струму. З метою підвищення ККД запропонована нова комбінована електромагнітна та магнітоелектрична система збудження зварювального генератора. Розроблена методика розрахунку електромагнітних характеристик генератора за результатами розрахунку магнітного поля методом скінчених елементів. Проведено аналіз впливу торцевих полів розсіювання на адекватність моделі постійного магніту прийнятої при розрахунку магнітного поля. Розроблена математична модель залежності усталеності горіння дуги від довжини повітряного зазор
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8

Santos, Michelly Christine dos. "Nanopartículas magnéticas funcionalizadas com bicamada de ácido láurico: caracterização, associação de moléculas bioativas e estudo de interação com BSA." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tede/8867.

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Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-09-10T18:22:00Z No. of bitstreams: 2 Dissertação- Michelly Christine dos Santos - 2012.pdf: 1834625 bytes, checksum: af88a6d02e2b5362de31315d2c4ff78c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-09-11T11:11:24Z (GMT) No. of bitstreams: 2 Dissertação- Michelly Christine dos Santos - 2012.pdf: 1834625 bytes, checksum: af88a6d02e2b5362de31315d2c4ff78c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf842
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Pennanen, T. (Teemu). "Computational studies of NMR and magneto-optical rotation parameters in water." Doctoral thesis, University of Oulu, 2012. http://urn.fi/urn:isbn:9789514297311.

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Abstract In this thesis nuclear magnetic resonance (NMR) and magneto-optical rotation (MOR) parameters are investigated for water, paying special attention to the effect of solvation from gaseous to liquid phase. Nuclear magnetic shielding and quadrupole coupling tensors of NMR spectroscopy are studied for gaseous and liquid water. Liquid state is modelled by a 32-molecule Car-Parrinello molecular dynamics simulation, followed by property calculations for the central molecules in clusters cut out from the simulation trajectory. Gaseous state is similarly represented by a one-molecule simulatio
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10

Austrin, Lars. "On magnetic amplifiers in aircraft applications." Licentiate thesis, Stockholm : Elektrotekniska system, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4439.

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11

Santos, Francisco Paulo dos. "Determinação e analise das constantes de acoplamento nJch (n=2,3,4) em derivados do norbornano." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250095.

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Orientador: Claudio Francisco Tormena<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica<br>Made available in DSpace on 2018-08-14T14:30:02Z (GMT). No. of bitstreams: 1 Santos_FranciscoPaulodos_D.pdf: 15350887 bytes, checksum: 67e192401b6f5d14d6d2568ea89baff1 (MD5) Previous issue date: 2009<br>Resumo: A tese está estruturada da seguinte forma. Primeiro uma parte introdutória relatando o efeito das interações hiperconjugativas na constante de acoplamento JXY e uma discussao sobre a as principais metodologias para a determinação de constantes de acoplamento a JXY a l
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12

Kato, T., 剛志 加藤, K. Nakazawa, et al. "Compositional Dependence of g-Factor and Damping Constant of GdFeCo Amorphous Alloy Films." IEEE, 2008. http://hdl.handle.net/2237/11190.

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13

Cui, Han. "Constant-Flux Inductor with Enclosed-Winding Geometry for Improved Energy Density." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/34722.

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The passive components such as inductors and capacitors are bulky parts on circuit boards. Researchers in academia, government, and industry have been searching for ways to improve the magnetic energy density and reduce the package size of magnetic parts. The â constant-fluxâ concept discussed herein is leveraged to achieve high magnetic-energy density by distributing the magnetic flux uniformly, leading to inductor geometries with a volume significantly lower than that of conventional products. A relatively constant flux distribution is advantageous not only from the density standpoint, bu
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14

Favaro, Denize Cristina 1987. "Determinação e análise da influência angular e eletrônica nas constantes de acoplamento nJCH em 2-X-4-t-butilcicloexanonas e 2-X-4-t-butilcicloexanóis (X=H, Me, F, Cl, Br)." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250091.

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Orientador: Claudio Francisco Tormena<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química<br>Made available in DSpace on 2018-08-17T19:41:15Z (GMT). No. of bitstreams: 1 Favaro_DenizeCristina_M.pdf: 2968237 bytes, checksum: 07a91d8f375b71e3ddc4d4c9b7818162 (MD5) Previous issue date: 2011<br>Resumo: A dissertação consiste de uma parte introdutória que versa sobre constantes de acoplamento JXH que seguem ou não uma relação de estrita dependência com o ângulo diedro, proposta por Karplus para JHH e por Aydin e Günther para JCH; apresentando como as interações hip
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15

Silva, Caio Ricardo Faiad da 1987. "Estudo experimental de teórico das constantes de acoplamento n ANTPOT. ('J IND. ch') (n= 1,2,3) em adamantanos substituídos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249182.

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Orientador: Roberto Rittner Neto<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química<br>Made available in DSpace on 2018-08-20T02:42:28Z (GMT). No. of bitstreams: 1 Silva_CaioRicardoFaiadda_M.pdf: 3324014 bytes, checksum: 2a09da96b3179c4cc07eb8d6923bcdd1 (MD5) Previous issue date: 2011<br>Resumo: A introdução da dissertação consiste na breve descrição da racionalização de acoplamentos JCH (n = 1, 2 e 3), das etapas de cálculos teóricos e das duas técnicas recentemente implementadas no IQ-Unicamp: HSQC-TOCSY-IPAP e IPAP-HSQMBC. A primeira parte da seção Result
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16

Sun, P., J. R. Jokipii, and J. Giacalone. "PITCH-ANGLE SCATTERING OF ENERGETIC CHARGED PARTICLES IN NEARLY CONSTANT MAGNITUDE MAGNETIC TURBULENCE." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621389.

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We use a method developed by Roberts. that optimizes the phase angles of an ensemble of plane waves with amplitudes determined from a Kolmogorov-like power spectrum, to construct magnetic field vector fluctuations having nearly constant magnitude and large variances in its components. This is a representation of the turbulent magnetic field consistent with that observed in the solar wind. Charged-particle pitch-angle diffusion coefficients are determined by integrating the equations of motion for a large number of charged particles moving under the influence of forces from our predefined magne
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17

Wang, Guisheng. "The Effect of Long Range Order on Elastic Properties of Alloys." Licentiate thesis, KTH, Tillämpad materialfysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-152529.

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Ab initio alloy theory, formulated within the exact muffin-tin orbitals method in combination with the coherent-potential approximation, is used to determine the effect of long range order on the elastic properties. The lattice parameters and single-crystal elastic constants of Cu3Au are calculated for different partially ordered structures ranging from the fully ordered L12 to the random face centered cubic lattice. Special attention is put on the chemical and magnetic effects and on the interplay between these two degrees of freedom. For non-magnetic Cu3Au, it was found that the lattice para
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18

Adam, Ahmad Yahia. "Theoretical Prediction of Nuclear Magnetic Shielding Constants of Acetonitrile." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/76769.

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Gauge invariant shielding constants calculations of ?H, ?C, and ??N were calculated for acetonitrile in the gas and liquid phases. Dierent basis sets as well as dierent ab initio and DFT methods were tested to select a time-ecient level of theory with reasonable accuracy. The eect of nuclear motion on the shielding constants was also explored. To investigate solvent eects on the shielding constants of acetonitrile, dierent clusters were extracted from molecular dynamics simulations. Convergence to the experimental values varied for the dierent clusters. The geometry of the central molecule in
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19

Delczeg-Czirjak, Erna-Krisztina. "Energy Relevant Materials: Investigations Based on First Principles." Licentiate thesis, KTH, Materialvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-25050.

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Energy production, storage and efficient usage are all crucial factors for environmentally sound and sustainable future technologies. One important question concerns the refrigeration industry, where the energy efficiency of the presently used technologies is at best 40% of the theoretical Carnot limit. Magnetic refrigerators offer a modern low-energy demand and environmentally friendly alternative. Iron phosphide based materials have been proposed to be amongst the most promising candidates for working body of magnetic refrigerators. Hydrogen is one of the central elements on the most promisi
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20

Favaro, Denize Cristina 1987. "Estudo dos mecanismos de transmissão dos acoplamentos escalares via ligação e/ou via nuvem eletrônica próxima no espaço e estudos de difusão (DOSY) de 19F." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250094.

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Orientador: Claudio Francisco Tormena<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química<br>Made available in DSpace on 2018-08-26T02:29:08Z (GMT). No. of bitstreams: 1 Favaro_DenizeCristina_D.pdf: 6372818 bytes, checksum: c89cc5eb491bd0129e563fc2dd200aac (MD5) Previous issue date: 2014<br>Resumo: A tese "Estudo dos mecanismos de transmissão dos acoplamentos escalares via ligações e/ou via nuvem eletrônica próxima no espaço e estudos de difusão (DOSY) de 19F" é composta de 5 capítulos. O primeiro capítulo é uma visão geral sobre Ressonância Magnética Nuclear (RMN),
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21

Castro, Aguilera Abril Carolina. "Computational study of nuclear magnetic shielding constants." Doctoral thesis, Universitat de Girona, 2017. http://hdl.handle.net/10803/565597.

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Nuclear Magnetic Resonance (NMR) spectroscopy is an indispensable structural tool in the modern analytical arsenal of chemists and structural biologists. The present thesis is a computational study of the NMR shift constants in a number of chemical systems of interest, using both static and dynamic approaches via Density Functional Theory, to predict, confirm the presence of transient species, and/or explain ambiguous signals in the NMR spectra. Special attention was put on cases where there are strong interactions between the solvent and the molecule studied. In addition, this thesis addresse
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22

Randewijk, Peter-Jan. "Analysis of a radial flux-air-cored permanent magnet machine with a double-sided rotor and non overlapping windings." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20246.

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Thesis (PhD)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: In this dissertation a new type of electrical machine, a Radial Flux Air-Cored Permanent Magnet machine with a Double-sided Rotor and utilising concentrated, non-overlapping windings, is proposed. The concept of the Double-sided Rotor Radial Flux Air-Cored Permanent Magnet machine, or RFAPM machine for short, was derived from the Double-sided Rotor Axial Flux Air-Cored Permanent Magnet (AFAPM) machine. One of the problems that AFAPM machines experience, is the deflection of the rotor discs due to the strong magnetic pull o
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23

Saldanha, Carlos M. "An algebraic constraint system for computer-aided design in magnetics /." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=64003.

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24

Richardson, Julia Margaret. "The measurement of coupling constants and the use of heteronuclear cross-polarisation in NMR experiments for the study of proteins." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281970.

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25

Russ, Jennifer Lynn. "Studies of Solution Paramagnetic-Substrate Nuclear and Electron Intermolecular Interactions." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/27050.

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Advanced nuclear and electron magnetic resonance techniques (i.e. nuclear magnetic resonance (NMR), dynamic nuclear polarization (DNP), and magnetic resonance imaging (MRI)) were used to study the attitude and dynamics of TEMPO (2,2,6,6-tetramethylpiperidinyloxy)-substrate systems and the relaxivity properties of water-soluble trimetallic nitride template functionalized endohedral metallofullerenes (TNT-fMF). The attitude and average distance of interaction for each TEMPO-substrate system was determined from comparing density functional theory (DFT) calculation results with experimental hyper
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26

Negodaev, Igor. "The calculation of the thermal dependency of the magnetic susceptibility in extended systems with ab initio electronic structure parameters." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/31934.

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La tesi estudia l'acoblament magnètic en sistemes de diferent dimensionalitat amb mètodes multireferencials. L’objectiu principal del treball és calcular propietats macroscòpiques, com la dependència de la susceptibilitat magnètica amb la temperatura, a partir de la constant d'intercanvi magnètic calculada, J. Aquest paràmetre microscòpic quantifica la interacció magnètica entre dos centres i es pot extreure per ajust de la corba de susceptibilitat experimental en sistemes finits però això no és possible en sistemes magnètics infinits com cadenes o capes 2D. L’estratègia del treball és cal
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27

Chater, Rabah. "Etude des antimonites MeSb 2 O 4 à basse température : évolution structurale, thermodynamique, propriétés élastiques et magnétiques anisotropes ; modélisation." Paris 6, 1986. http://www.theses.fr/1986PA066219.

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Etude par diffraction des RX et de neutrons, spectroscopie Raman et IR, chaleur massique, susceptibilité magnétique des antimonites (MNNifezn)sb2o4. Interprétation quantitative des anomalies de dilatation liées à Tltn dans le cas des composés de Ma et Fe. Définition d'un champ de force cohérent avec un potentiel de paires simplifié.
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28

Leach, Jacob H. "Tuning of electrical properties in InAlN/GaN HFETs and Ba0.5Sr0.5TiO3/YIG Phase Shifters." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2035.

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Engineers know well from an early point in their training the trials and tribulations of having to make design tradeoffs in order to optimize one performance parameter for another. Discovering tradeoff conditions that result in the elimination of a loss associated with the enhancement of some other parameter (an improvement over a typical tradeoff), therefore, ushers in a new paradigm of design in which the constraints which are typical of the task at hand are alleviated. We call such a design paradigm “tuning” as opposed to “trading off”, and this is the central theme of this work. We investi
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Sá, Franciéli Lima de. "Estudo do acionamento do motor síncrono de ímãs permanentes: abordagem baseada no controle vetorial com ângulo de torque constante." Universidade do Estado de Santa Catarina, 2010. http://tede.udesc.br/handle/handle/1904.

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Made available in DSpace on 2016-12-12T17:38:37Z (GMT). No. of bitstreams: 1 FRANCIELI LIMA DE SA.pdf: 957791 bytes, checksum: 54a198d079685e3726016b54e682ffdc (MD5) Previous issue date: 2010-07-30<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>In this work is introduced a study of Permanent Magnet Synchronous Motor (PMSM), involving issues about constructive characteristics, modeling, control and simulation. Initially, are studied the constructive characteristics, principally in that refers of the magnets disposition in the rotor. Then, are shown some applications for the
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30

Huang, Lunmei. "Computational Material Design : Diluted Magnetic Semiconductors for Spintronics." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7800.

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Sbai, Youssef. "Analyse semi-classique des opérateurs périodiques perturbés." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0270/document.

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Cette thèse traite de certaines propriétés spectrales de deux classes spécifiques des opérateurs périodiques. Nous nous intéressons tout d’abord à un modèle périodique perturbée par un opérateur dépendant d’un petit paramètre semi-classique. Nous obtenons alors le comportement asymptotique de la fonction du comptage des valeurs propres dans les gaps spectrales avec une estimation optimale du reste. Le second modèle étudié dans cette thèse est un modèle elliptique périodique d’ordre deux perturbée par un opérateur dépendant d’une grande constante de couplage. Nous donnons également la descripti
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32

Chen, Fu-Tseng Andy. "Molecular Dynamics in the Liquid Phase by FT-NMR, FT-IR and Laser Raman Lineshape Analysis." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc330608/.

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Nuclear magnetic resonance (NMR) provides a convenient probe for the study of molecular reorientation in liquids because nuclear spin-lattice relaxation times are dependent upon the details of molecular motion. The combined application of Raman and Infrared (IR) lineshape analysis can furnish more complete information to characterize the anisotropic rotation of molecules. Presented here are the studies of NMR relaxation times, together with Raman/IR Mneshape analysis of the solvent and temperature dependence of rotational diffusion in 1,3,5-tribromobenzene and 1,3,5-trifluorobenzene. In these
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33

Vérot, Martin. "Phénomènes de transport : contribution de l'approche ab initio et applications." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2013. http://tel.archives-ouvertes.fr/tel-00866347.

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Dans une première partie, nous avons étudié quelques propriétés de molécules magnétiques impliquant des radicaux organiques (seuls ou conjointement avec des terres rares). Nous avons ainsi pu interpréter l'évolution de la susceptibilité magnétique et de l'aimantation en fonction de la température en évaluant par des approches ab initio fonctions d'onde les constantes d'échange ou le tenseur g au sein de ces matériaux. De plus, nous avons chercher à définir les conditions pour que des matériaux à base de radicaux organiques présentent simultanément des propriétés magnétiques et conductrices. No
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Hoogerheide, Shannon Michelle Fogwell. "Trapped positrons for high-precision magnetic moment measurements." Thesis, Harvard University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3566927.

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<p> A single electron in a quantum cyclotron provides the most precise measurement of the electron magnetic moment, given in units of the Bohr magneton by <i> g</i>/2 = 1.001 159 652 180 73 (28) [0.28 ppt]. The most precise determination of the fine structure constant comes from combining this measurement with Standard Model theory, yielding &alpha;<sup>-1</sup> = 137.035 999 173 (34) [0.25 ppb], limited by the experimental uncertainty of the electron <i> g</i>-value. The most stringent test of CPT symmetry in leptons comes from comparing the electron and positron magnetic moments, limited by
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35

Majumdar, Madhabi. "Elastic Constants, Viscosities and Fluctuation Modes of Certain Bent-Core Nematic Liquid Crystals Studied by Dynamic Light Scattering and Magnetic Field Induced Orientational Distortion." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1321991835.

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36

Bracikowski, Nicolas. "Modélisation multi-physique par modèles à constantes localisées ; application à une machine synchrone à aimants permanents en vue de son dimensionnement." Phd thesis, Ecole Centrale de Lille, 2012. http://tel.archives-ouvertes.fr/tel-00905641.

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Afin de définir une conception optimale d'un système électromécanique, celui-ci doit intégrer des contraintes toujours plus drastiques et de nombreux phénomènes physiques issus de : l'électromagnétique, l'aérothermique, l'électronique, la mécanique et l'acoustique. L'originalité de cette thèse est de proposer une modélisation multi-physique pour la conception reposant sur des modèles à constantes localisées : solution intermédiaire entre la modélisation analytique et numérique. Ces différents modèles permettront l'étude et la conception sous contraintes d'une machine synchrone à aimants perman
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Ennassiri, Hamza. "Analyse magnéto-vibroacoustique des machines synchrones discoides à commutation de flux dédiées aux véhiculex électriques hybrides." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMLH36/document.

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Ce mémoire de thèse traite la problématique des émissions vibroacoustiques dès les premières phases de conception de machines électriques dans le but de mettre en œuvre des machines robustes, fiables et surtout efficientes répondant aux contraintes dans un large domaine d’applications et spécialement pour le véhicule électrique et hybride. Ce manuscrit ne s’intéresse pas seulement à l’identification et la mise en exergue de la problématique vibroacoustique mais surtout a apporté des solutions et des éléments de réponse à certaines contraintes. La problématique vibroacoustique étant trop vaste
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38

McKinnon, Douglas John Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Novel efficiency evaluation methods and analysis for three-phase induction machines." Awarded by:University of New South Wales. Electrical Engineering and Telecommunications, 2005. http://handle.unsw.edu.au/1959.4/21869.

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This thesis describes new methods of evaluating the efficiency of three-phase induction machines using synthetic loading. Synthetic loading causes the induction machine to draw full-load current without the need to connect a mechanical load to the machine's drive shaft. The synthetic loading methods cause the machine to periodically accelerate and decelerate, producing an alternating motor-generator action. This action causes the machine, on average over each synthetic loading cycle, to operate at rated rms current, rated rms voltage and full-load speed, thereby producing rated copper losses,
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39

Parzefall, Ulrich. "A measurement of trilinear gauge couplings using the DELPHI detector." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366942.

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40

Fronk, Michael. "Charakterisierung von dia-, para- und ferromagnetischen dünnen Schichten mittels magnetooptischer Kerr-Effekt-Spektroskopie." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-61755.

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Die polare magnetooptische Kerr-Effekt-Spektroskopie (MOKE) wird in dieser Arbeit zum ersten Mal zur Charakterisierung paramagnetischer Schichten eingesetzt. Die Schichten bestehen aus Phthalocyanin-Molekülen (H2Pc, VOPc, MnPc, CoPc und CuPc), die sich als Modellsystem zur Untersuchung des Einflusses des Molekülzentrums auf die elektronischen Zustände eignen. Die optischen Konstanten und die Dicken der Schichten werden mittels Ellipsometrie bestimmt. Mithilfe eines optischen Schichtmodells wird aus den Ellipsometrie- und MOKE-Daten die Voigt-Konstante, ein magnetooptischer Materialparameter, b
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41

Teixeira, Julio Carlos. "Étude des machines synchrones à aimants permanents fonctionnant en réduction de flux." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0074.

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Dans ce travail, une machine synchrone à aimants permanents a été étudiée pour fonctionner lorsque les limitations de la source d'alimentation (en tension et en courant) imposent une réduction de flux résultant. Nous avons tout d'abord décrit les équations nécessaires à l'étude de la machine contrôlée par les courants afin de comprendre globalement les rapports nécessaires entre les paramètres caractéristiques de la machine. Nous nous sommes particulièrement intéressés au régime saturé. Nous avons ensuite étudié les contraintes imposées par le fonctionnement en réduction de flux dans quelques
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42

Benhamida, Mohammed Ali. "Investigation de nouvelles technologies de générateurs pour les éoliennes offshore." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMLH11/document.

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Ce mémoire de thèse constitue une contribution à l'investigation des génératrices destinées à une application éolienne en mer. Le but est de rechercher les solutions optimales dans un domaine de recherche vaste contenant entre huit et onze variables d'optimisation, tout en respectant un cahier de charge bien précis. Afin d'y parvenir, un modèle multi-physique a été développé permettant la détermination des distributions du champ électromagnétique et de température dans les topologies de génératrices choisies avec prise en considération des non-linéarités des matériaux. La méthode des constante
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43

Aveiro, Susana Seabra. "The p22HBP heme binding protein: an NMR study of the dynamics and heme-protein interactions." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/14278.

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Doutoramento em Bioquímica<br>The work presented in this Thesis investigates the dynamics and molecular interactions of p22HBP and the p22HBP-tetrapyrrole complex. Specifically, the key residues involved when a tetrapyrrole binds to p22HBP were sought. Previous molecular modelling studies identified three possible charged residues R56, K64 and K177 as possibly being important in tetrapyrrole binding via electrostatic interactions with the propionate groups of the tetrapyrrole. A number of variants of murine p22HBP were therefore prepared and fluorescence quenching and NMR used to verify the in
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44

Najib, Abdelkrim. "Etude de quelques composés de cérium du type fermions lourds : corrélations, cohérence, diagrammes de phases sous pression." Grenoble 1, 1988. http://www.theses.fr/1988GRE10064.

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Etude des composes ce in cu::(2), ce mg et ce cu::(6). Les etudes de susceptibilite magnetique, resistivite electrique et chaleur specifique sur les solutions solides(ce-y)incu::(2) et (ce-la)incu::(2) mettent en evidence des correlations antiferromagnetiques dans le compose ceincu::(2). Influnce des impuretes sur la coherence du reseau. Determination pour ce compose du coefficient de grueneisen a partir des proprietes de transport sous pression hydrostatique. Etude pour les autres composes des diagrammes de phase sous pression hydrostatique jusqu'a 130 kbar
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45

Pientka, Grit. "Hadronic corrections to electroweak observables from twisted mass lattice QCD." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17312.

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Für verschiedene Richtgrößen, die untersucht werden, um Hinweise auf Neue Physik jenseits des Standardmodells der Teilchenphysik zu finden, stellt die Gitter-QCD stellt derzeit den einzigen Ab-initio-Zugang für die Berechnung von nichtperturbativen hadronischen Beiträgen dar. Zu diesen Observablen gehören die anomalen magnetischen Momenten der Leptonen und das Laufen der elektroschwachen Kopplungskonstanten. Wir bestimmen den führenden QCD-Beitrag zum anomalen magnetischen Moment des Myons mit Hilfe einer Gitter-QCD-Rechnung auf Ensemblen, die Nf=2+1+1 dynamische Twisted-Mass-Fermionen berüc
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46

Fouassier, Patrick. "Modélisation électrique des composants magnétiques haute fréquence : prise en compte de la température et caractérisation des ferrites." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0108.

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L'augmentation des fréquences de fonctionnement des convertisseurs statiques de l'Electronique de Puissance a rendu obligatoire une modélisation plus réaliste des composants magnétiques. Déduit uniquement de mesures extérieures au composant, le circuit électrique équivalent qui leur est associé comporte une vingtaine d'éléments discrets. Déterminé de façon systématique, grâce à une approche théorique et expérimentale rigoureuse, et rapide, grâce à l'utilisation de moyens informatiques adaptés, il permet de représenter l'ensemble des phénomènes physiques qui interviennent du continu jusqu'à une
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47

Berthier, Serge. "Théories de la fonction diélectrique optique des milieux inhomogènes : application aux propriétés électromagnétiques des cermets." Paris 6, 1986. http://www.theses.fr/1986PA066283.

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Analyse comparative des différentes théories de la fonction diélectrique optique des milieux inhomogènes aléatoires macroscopiques (MIAM). Résultats expérimentaux sur le comportement diélectrique de 5 échantillons au-MGO dont la concentration volumique en métal n'excède pas 0,41; apparition de la résonnance de plasmon de surface sur tous les échantillons entre 550 et 600 nm. Nouvelles approches: théorie de Bruggeman modifiée, méthode des groupes de renormalisation. Applications dans les capteurs solaires
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48

Specht, Michael. "Etude expérimentale de systèmes désordonnés dans le régime de la localisation d'Anderson." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10067.

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Ce travail est consacre a l'etude de la phase isolante de systemes desordonnes dans le regime de la localisation d'anderson. Les etats electroniques sont localises sur une echelle characteristique, la longueur de localisation, suite a des interferences destructives induites par le desordre. L'effet d'un champ magnetique sur la longueur de localisation a suscite plusieurs travaux theoriques recents. D'un cote la theorie de matrices aleatoires propose une dependance universelle de la longueur de localisation en fonction de la symmetrie du systeme. Un champ magnetique brise la symmetrie par rappo
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49

Nasri, Ridha. "Conception et réalisation d'un adaptateur haute impédance programmable : epplication à la caractérisation de liquides magnétiques." Saint-Etienne, 1994. http://www.theses.fr/1994STET4014.

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Ce travail s'inscrit dans le cadre de la recherche sur les ferrofluides ou liquides magnétiques. Les évolutions, qui peuvent être rapides, des propriétés diélectriques de ces matériaux telles que les changements de phase du liquide porteur, la perte d'homogénéité par formation d'agrégats ou de multicouches nécessitent l'automatisation complète de l'acquisition des mesures. Pour cela, nous avons développé autour d'un analyseur vectoriel, un adaptateur haute impédance programmable en mode shunt fonctionnant dans la gamme 1mhz-10khz. Cette réalisation fait appel à l'électronique haute impédance :
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50

Loppinet, Benoit. "Etude de la structure de solutions d'ionomères en solvants polaires par diffusion aux petits angles." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10208.

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Ce travail presente l'etude, principalement par diffusion aux petits angles (dpa) de neutrons et de rayons-x, de solutions d'ionomeres. Les differentes analyses de l'intensite dpa (variation de contraste, analyse du comportement asymptotique, positions du pic d'interferences), appliquees aux solutions d'ionomeres perfluores (ipf), menent a la conclusion de la presence de particules colloidales de symetrie cylindrique. Cette geometrie est obtenue pour des solutions de trois ipf dans des solvants varies couvrant une gamme importante de constante dielectrique. La valeur du rayon depend de l'ipf e
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