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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"Magnetic permeability."”.
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Chemical Correlation of Magnetic Permeability and Microwave Absorption in Spinel Ferrite Nanoparticles
… (MFe₂O₄, where M = Mn²⁺, Co²⁺, Zn²⁺, etc.) are magnetic nanomaterials with tunable properties that are valuable for wireless communication, memory storage, and electronics. Their complex permeabilities that are governed by composition, particle size, and spin-orbit interactions play a critical …
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Rotational speed dependent motor properties
… drops motor efficiency steeply. By reducing the magnetic flux surrounding the coil of the stator, back EMF can be reduced and motor efficiency can be maintained at any rotational speed. Several prototypes that take advantage of centrifugal force and moving motor components are created; the …
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Computer-Aided Formulation of Magnetic Pastes for Magnetic Components in Power Electronics
Magnetic components are necessary for switch-mode power electronics converters, but they are often the bulkiest and heaviest in the system. Novel magnetic designs with intricate structures lead to the size reduction of power electronics converters but pose challenges to the fabrication process and …
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Composite Nanoparticle Materials for Electromagnetics
… as a viable replacement for conventionally used magnetic core materials in various electromagnetic applications. Conventional linear and rotary electric motors, generators and actuators are too bulky to be used in lightweight applications. The major component of weight in electromagnetic devices …
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Design and Processing of Ferrite Paste Feedstock for Additive Manufacturing of Power Magnetic Components
Reducing the size of bulky magnetic components (inductors and transformers) in power converters can be achieved by increasing switching frequency and applying innovative designs of magnetic components. Ferrite is the most suitable bulk magnetic material for working at high frequencies but it is …
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Analysis of Mueller matrices of metamaterials and multiferroics
The optical spectra of complex materials such as magnetic-dielectric media, magnetoelectric and multiferroic crystals, materials with intrinsic chirality, and metamaterials are studied. These media are important both for: (i) their interesting optical effects, such as Negative Index of Refraction …
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The Effect of Phase Transformation on The Fatigue Crack Growth Rate of Austenitic Stainless Steels Tested in Argon and Hydrogen Atmospheres
… of martensite was determined by measuring the magnetic permeability and by using quantitative metallography. The phase present along the path of the fatigue crack was determined by using glancing incidence electron diffraction.
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Non-Destructive Testing of metallic structures based on electromagnetic computational methods
… between 2018 to 2021 and focuses on electromagnetic (EM) computational methods in the field of non-destructive testing (NDT).<br/><br/>Conductive samples affect the electromagnetic field generated by coils with alternating induced currents. Referring to eddy current effects, materials with …
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Finite Element Analysis Of Left-handed Waveguides
… negative dielectric permittivity and magnetic permeability, otherwise known as left-handed waveguides, are investigated. An approach of formulating and solving an eigenvalue problem with finite element method resulting in the dispersion relation of the waveguides is adopted in the …
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Electrically insulating phosphate coatings for iron powder based electromagnetic core applications
… as iron, are a common building block for electromagnetic cores. An iron powder was reacted with phosphoric acid to create a layer of iron phosphate on each particle. This electrically insulating phosphate layer could lead to significant reductions in eddy current losses in alternating current …
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Multiferroic Bismuth Ferrite-Lead Titanate and Iron-Gallium Crystalline Solutions: Structure-Property Investigations
… two of the ferroelectric, ferroelastic and ferromagnetic effects-have attracted enormous research activities. In this thesis, the structure and properties of multiferrioic BiFeO3-x%PbTiO3 and Fe-x%Ga crystalline solutions were investigated. First, the results show that modified BiFeO3-PbTiO3 …
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Modeling effects of adding a flux channel to a planar magnet-coil actuator
… force depends on the current vector and the magnetic field vector. In this thesis the Lorentz force is altered by changing the direction and concentration of the magnetic field. Magnetic fields may be modeled as flux lines traveling from the north face of the magnet to the south face along …
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Improvement to hydrocyclone used in separating particles from produced water in the oil and gas industry.
… oil and induced magnetism is referred to as magnetic hydrocyclone. Computational fluid dynamics (CFD) were employed for analysis of the fluid flow in the hydrocyclone; a review of the turbulence model shows that the Reynold stress model (RSM) and Large eddy simulation (LES) are the best …
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Magnetic Manipulation and Assembly of Multi-component Particle Suspensions
… investigate previously unexplored concepts in magnetic manipulation including controlling the assembly of magnetic and nonmagnetic particles either in bulk fluid or near a substrate. Both uniform glass interfaces and substrates with magnetic microstructures are considered. The main goal of this …
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Effect of Heat Treatment on Magnetic and Mechanical Properties of an Iron-Cobalt-Vanadium-Niobium Alloy
… alloys can be processed to have excellent soft magnetic properties for use in high performance power generation applications such as the rotors and stators of aircraft integrated power units. These soft magnetic properties are, however, developed at the expense of mechanical strength and …
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Modeling and fabrication of self-assembling micron-scale rollup structures
… properties lead to, a negative effective magnetic permeability for a narrow frequency band, potentially in the far infrared region. These structures thus can contribute a vital component ([mu]eff < 0) necessary for developing a LHM (left-handed material). Many successful materials …
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Thermal-magnetic finite element model of a high frequency transformer
In high-frequency power transformers, magnetic material properties cannot be assumed to be constant. These properties vary with frequency, temperature, and magnetic flux density. Heat generation is, in turn, a function of the magnetic permeability, magnetic flux density, and frequency. Current …
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Thermo-Capillary Driven Flow Under the Influence of Rotation and Magnetic Fields
… driven flow is sought using (1) rotation and (2) magnetic field, and the effects of these are computationally studied in two separate parts. In the first part, the main parameters are the solutal Marangoni number Mc, representing the surface tension gradient force and the Taylor number Ta …
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Magnetic fields and ultracold neutron production: studies towards the neutron electric dipole moment experiment at TRIUMF
… measured in the presence of aligned Electric and Magnetic fields orientations. Such precision measurements require high UCN statistics and very stable and homogeneous magnetic fields. The work presented in this thesis is focused on the magnetic field and UCN studies for the future nEDM measurement …
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Ferrofluid flow phenomena
… size range, saturation magnetization, low-field magnetic permeability, and magnetic volume fraction. The experimental results are well described by the Langevin theory of paramagnetism. A detailed discussion of the demagnetization factor within the ferrofluid sample is also included. Ferrofluid …
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