Global ETD Search
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 57 for “"Hysteresis Loops"”.
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Computer simulation studies of magnetic nanostructures
… more strongly the shape anisotropy affects the hysteresis loop.<br/><br/>We investigate the micromagnetic behaviour of ferromagnetic samples of various geometries using numerical methods. Finite differences and finite elements are used to solve the Landau-Lifshitz-Gilbert and Brown's equations …
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Suspended-sediment characteristics in four humid tropical watersheds of contrasting land use, Puerto Rico
… the main source of sediment and clockwise hysteresis loops are more common. Small rainfall events that occur between large flow events in forested basins flush some of this deposited sediment and reduce the sediment load of the next large runoff event. Quebrada Blanca a basin with small …
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Empirical Estimation of a Macroscopic Fundamental Diagram (MFD) for the City of Cape Town Freeway Network
… state, critical state and the formation of hysteresis loops past the critical density corresponding with the network observed maximum flow. Further analysis of the MFDs showed that a single hysteresis loop always forms past the critical density during the evening peak in a weekday MFD. …
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Friction and degradation of rubber coatings under fretting conditions
… investigated using friction forcedisplacement hysteresis loops and friction force variation with test frequency, fretting amplitude and fIlm thickness. Lastly, coating life variation with these three parameters was studied and explained through a simplified fatigue mechanics approach.
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Synthesis and Characterization of Nanostructures in Porous Anodic Aluminum Oxide Templates
… showed distinct differences in the squareness of hysteresis loops and coercivity both as a function of pore structure and magnetic component. Iron oxide nanotubes with a unique inner-surface were also fabricated by an electrodeposition method. β-FeOOH nanotubes were grown in alumina templates and …
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New perspectives of pure and lanthanum modified lead zirconate titanate crystalline solutions
… lattice, resulting in normal square dielectric hysteresis loops.
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Identification of an Unsteady Aerodynamic Model up to High Angle of Attack Regime
… mechanisms are discussed. Since no significant hysteresis loops are observed for the lift and the drag coefficients for the current angle of attack range and the tested reduced frequencies, the dynamic lags of separated and vortex flow effects are small in the current oscillatory tests. However, …
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An introduction to the study of magnetic amplifiers
… is developed from the standpoint of rectangular hysteresis loops that are simplified in such a manner as to eliminate the problems of nonlinearity. The saturable reactor may be connected in either series or parallel combinations and their operation analyzed on the basis of voltage, current, and …
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Optimizing hysteretic power loss of magnetic ferrite nanoparticles
… by physical models. By employing integration of hysteresis loops simulated from physical models for single-domain ferromagnets, we have identified ferrite materials optimal for remote heating. Several organometallic thermal decomposition methods were adapted to synthesize nanoparticles with …
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Fabrication, characterization, and micromagnetic analysis of lithographically defined particle arrays for applications in data storage
… field spread on the squareness and the shape of hysteresis loops is studied with the help of an Ising-like interaction model. Based on these observations, a stability condition for patterned media is found and used for determining the optimum spacing between nanomagnets.
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Three-dimensional modelling of metal evaporated tape
… resisted large negative fields and square hysteresis loops with a high coercivity were produced. Reversal of the moments was observed to be initiated at the ends of a column and then propagated throughout the column. This was attributed to large demagnetising fields and was particularly …
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Analysis of Memristor Hysteretic Systems: A Hybrid Coupled Model with emphasis on Pinching/Degrading Behavior
… of memristive devices exhibiting self-crossing hysteresis loops. The proposed model combines the Bouc-Wen Baber-Noori model with other non-linear elements in the resistive switching process. Existing models for memristive behavior, including physical-based memristive models, …
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Kraftmikroskopische Untersuchungen dünner ferroelektrischer Filme
… quantitative measurements of the ferroelectric hysteresis loops, and investigations at the interface between film and platinum-electrode in the PZT/Pt-System. Lamellar domain structures were visualized with high lateral resolution of 5nm on the surface of the PTO-samples, whereas the PZT- and …
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Structural control strategies for earthquake response reduction of buildings
… The relationship between force-displacement hysteresis loops produced by the linear quadratic regulator (LQR) and the linear quadratic Gaussian (LQG) algorithms is explored. Then, new simple algorithms are proposed, which can produce versatile hysteresis loops. Moreover, the proposed …
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Micromagnetic modelling and magneto-optical characterization of Ni/V2O3 hybrid structures
… done in the MOKE measurements. The result are hysteresis loops as a function of azimuthal angle yielding the normalized magnetic remanence and coercive field. This was done for two sample sizes with number of cells in x-, yand z- direction 128x128x2 and 256x256x2 both having cell size 4x4x10nm. …
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DETECTION OF MAGNETIZATION REVERSAL IN A NEODYMIUM-IRON-BORON MAGNET USING A HALL-EFFECT MICROPROBE
… samples which were cycled through minor hysteresis loops (maximum applied field of approximately 2 T): (1) virgin magnetization traces did not contain measurable Barkhausen steps, however all other forward and reverse magnetization traces did; (2) the initial reverse magnetization trace …
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Deposition and characterisation of bismuth layer-structured ferroelectric films
… be used in nanoscale device fabrication. Clear hysteresis loops were measured by PFM, which was an important proof of ferroelectricity. Large spatial variations of piezoelectric hysteresis loops of a CSD-derived BSmT film were observed across the film surface. Effective electrostriction …
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Analysis of Hysteretic Systems: Preisach Formalism and Bouc-Wen Modeling
The inherently nonlinear phenomenon of hysteresis is notoriously difficult to model. Of notable interest are the inverse models of hysteresis which identify the parameters of a particular model to closely match experimental data. Two major models of hysteresis are the Preisach and Bouc-Wen models. …
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Characterization of Novel Pyroelectrics
… method and the measurement of ferroelectric hysteresis loops is described. It was used to characterize and discuss the behavior of p with respect to the temperature of the doped bulk III-V compound semiconductors gallium nitride and aluminum nitride and thin films of doped hafnium oxide, as …
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Magnetic properties of block-copolymer fabricated cobalt nanodots and nanowires at elevated temperatures
… the reliability of the nanodots, magnetic hysteresis loops of three samples, Co5 Co7 and Co9, were taken at elevated temperatures up to 350°C Comparing room temperature magnetization to the ideal magnetization, percent of surface covered in nanodots was calculated to be 88%, 50%, and 60% …
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