Mostrando recursos 1 - 20 de 38

  1. Perturbation Finite Element Method for Refining Magnetic Circuit Models

    Dular, Patrick; Sabariego, Ruth,; Ferreira Da Luz, Mauricio,; Kuo-Peng, Patrick; Krähenbühl, Laurent

  2. Perturbation Finite Element Method for Refining Magnetic Circuit Models

    Dular, Patrick; Sabariego, Ruth,; Ferreira Da Luz, Mauricio,; Kuo-Peng, Patrick; Krähenbühl, Laurent

  3. Caracterización de circuitos no lineales : análisis de modelos algebraico-diferenciales mediante la teoría de grafos

    García de la Vega Chamorro, Ignacio
    La presente Tesis Doctoral tiene por objeto el estudio de ciertas propiedades de las ecuaciones algebraico-diferenciales que aparecen en el modelado de circuitos eléctricos y electrónicos no lineales. Se sitúa en la denominada aproximación estructural a la teoría de circuitos no lineales, que pretende caracterizar sistemáticamente diferentes propiedades analíticas de estos en términos de la topología del digrafo subyacente y de las propiedades eléctricas de los dispositivos que conforman el circuito. Diversos trabajos previos han abordado el estudio de propiedades tanto analíticas como, específicamente, cualitativas en el contexto de los circuitos no lineales y desde esa perspectiva estructural. Desde un...

  4. Complex dynamical networks constructed with fully controllable nonlinear nanomechanical oscillators

    Fon, Warren; Matheny, Matthew H.; Li, Jarvis; Krayzman, Lev; Cross, Michael C.; D'Souza, Raissa M.; Crutchfield, James P.; Roukes, Michael L.
    Control of the global parameters of complex networks has been explored experimentally in a variety of contexts. Yet, the more difficult prospect of realizing arbitrary network architectures, especially analog physical networks that provide dynamical control of individual nodes and edges, has remained elusive. Given the vast hierarchy of time scales involved, it also proves challenging to measure a complex network’s full internal dynamics. These span from the fastest nodal dynamics to very slow epochs over which emergent global phenomena, including network synchronization and the manifestation of exotic steady states, eventually emerge. Here, we demonstrate an experimental system that satisfies these...

  5. Diseño y desarrollo de un sistema Vehicle To Home (V2H) para vehículos eléctricos

    Campo Ávila, Jorge
    Actualmente, se habla del beneficio que conlleva en la reducción de emisiones CO2 el uso del vehículo eléctrico (VE). Sin embargo, no se tiene en cuenta el gran potencial que supone como almacenamiento eléctrico. En el capítulo del estado del arte se hablará de cómo los coches eléctricos serán claves en el sistema eléctrico. En concreto en este trabajo fin de grado se diseñará un sistema V2H (Vehicle To Home), sistema por el cual el VE es capaz de alimentar las necesidades de una vivienda en caso de un corte de luz. Para ello se desarrollará un prototipo de vehículo eléctrico...

  6. Generation of Equivalent Circuit From Finite-Element Model Using Model Order Reduction

    Sato, Yuki; Igarashi, Hajime
    This paper proposes an equivalent-circuit generation from the finite-element (FE) model of electromagnetic devices using a model order reduction (MOR). In this method, an equivalent circuit is directly generated from the reduced transfer function obtained using MOR based on Pade approximation via the Lanczos process. It is shown that the generated circuit yields sufficiently accurate results in both frequency and time domains. Moreover, the computational time of the present method is much shorter than that of the circuit generation based on frequency sweep using the conventional FE analysis.

  7. Experiment and Simulation of Impregnated No-Insulation REBCO Pancake Coil

    Noguchi, So; Monma, Katsutoshi; Iwai, Sadanori; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Ueda, Hiroshi; Ishiyama, Atsushi; Urayama, Shinichi; Fukuyama, Hidenao
    It is important to investigate the stability and behavior of an epoxy-resin-impregnated no-insulation (NI) REBCO pancake coil to implement high-field applications, such as ultra-high-field magnetic resonance imaging. We have performed sudden discharging and overcurrent tests for the impregnated NI REBCO pancake coil. From the discharging test, the contact resistivity is estimated, and it changes depending on the initial current. From the overcurrent test, the high thermal stability of the impregnated NI REBCO pancake coil is confirmed. The REBCO pancake coil is charged up to 67 A though the critical current is only 46 A, and no degradation has been found....

  8. Basic deposited integrated magnetic circuit element for fast computer circuitry

    Reardon, B. C.; Humphrey, F. B.
    A deposited configuration, consisting of a magnetic thin film and coupling loop, was studied with a view to the future development of integrated magnetic circuitry. A line charge model, predicting flux linkages of coupling loops to an accuracy of about one percent was established. The almost complete linkage of the film flux with a deposited loop, due to the very close coupling, was verified. A decrease of about 20 percent in film flux at both ends of the easy axis was noted for the experimental assemblies used. Circulating loop currents were shown to be the chief parasitic factor which modified...

  9. Piezoelectric micro-machined ultrasonic transducers for medical imaging

    Smyth, Katherine Marie
    Next generation medical imaging technology hinges on the development of cost effective and array compatible transducers making piezoelectric micro-machined ultrasonic transducers (pMUTs) an attractive alternative to the current bulk piezoelectric technology. This thesis aims to realize pMUT potential starting with the development of an effective single cell model that is further scaled to optimize multi-cell elements in a 1D array. In the first half of this work, a transverse mode, lead zirconate titanate (PZT) pMUT plate cell is fabricated using common micro-fabrication techniques and a PZT sol-gel deposition process. Through derivation using a novel Greens function solution technique, an equivalent...

  10. Optical Frequency Mixing Through Nanoantenna Enhanced Difference Frequency Generation: Metatronic Mixer

    Chettiar, Uday K; Engheta, Nader
    A design for a subwavelength all-optical frequency mixer is proposed. The method relies on enhanced difference-frequency generation, which is achieved in two steps with the help of plasmonic nanoantennas. The interaction of the two input signals with the nonlinear material is increased through the use of input nanoantennas, which focus the incident energy of two different frequencies onto the nanoparticle formed by a nonlinear material. Next, the difference-frequency emission is enhanced through the Purcell effect by the use of a separate output nanoantenna that is resonant at the difference frequency. The application of this twofold approach allows for a significant...

  11. Generation and tuning of learned sensorimotor behavior by multiple neural circuit architectures

    Lynn, Michael (Michael Benjamin)
    Organisms have a remarkable ability to respond to complex sensory inputs with intricate, tuned motor patterns. How does the brain organize and tune these motor responses, and are certain circuit architectures, or connectivity patterns, optimally suited for certain sensorimotor applications? This thesis presents progress towards this particular problem in three subprojects. The first section re-analyzes a large data set of single-unit recordings in zebra finch area HVC during singing. While HVC is known to be essential for proper expression of adult vocalization, its circuit architecture is contentious. Evidence is presented against the recently postulated gesture-trajectory extrema hypothesis for the organization...

  12. A Superconducting-Nanowire 3-Terminal Electronic Device

    McCaughan, Adam N.; Berggren, Karl K.
    Superconducting electronics based on Josephson junctions are used to sense and process electronic signals with minimal loss; however, they are ultrasensitive to magnetic fields, limited in their amplification capabilities, and difficult to manufacture. We have developed a 3-terminal, nanowire-based superconducting electrothermal device which has no Josephson junctions. This device, which we call the nanocryotron, can be patterned from a single thin film of superconducting material with conventional electron-beam lithography. The nanocryotron has a demonstrated gain of >20, can drive impedances of 100 kΩ, and operates in typical ambient magnetic fields. We have additionally applied it both as a digital logic...

  13. Espacio deportivo urbano : parkour park en Vigo

    Lago Costas, Alfredo Alberto
    En la Península Ibérica se está viviendo un fenómeno emergente en el panorama deportivo: el auge del Parkour, deporte urbano que se sirve de la morfología de la ciudad aprovechando elementos del mobiliario, escaleras, desniveles y rampas para realizar circuitos y piruetas. Al tratarse de un deporte relativamente nuevo existe una falta de estudio de la relación del deporte con el entorno urbano. Es por ello que tampoco existen muchas construcciones a día de hoy que conjuguen las necesidades del parkour con la morfología y circuitos urbanos. La ciudad de Vigo tiene un papel destacable dentro de la comunidad gallega, debido...

  14. GATA Factor-G-Protein-Coupled Receptor Circuit Suppresses Hematopoiesis

    Gao, Xin; Wu, Tongyu; Johnson, Kirby D.; Lahvic, Jamie L.; Ranheim, Erik A.; Zon, Leonard I.; Bresnick, Emery H.
    Summary Hematopoietic stem cells (HSCs) originate from hemogenic endothelium within the aorta-gonad-mesonephros (AGM) region of the mammalian embryo. The relationship between genetic circuits controlling stem cell genesis and multi-potency is not understood. A Gata2 cis element (+9.5) enhances Gata2 expression in the AGM and induces the endothelial to HSC transition. We demonstrated that GATA-2 rescued hematopoiesis in +9.5−/− AGMs. As G-protein-coupled receptors (GPCRs) are the most common targets for FDA-approved drugs, we analyzed the GPCR gene ensemble to identify GATA-2-regulated GPCRs. Of the 20 GATA-2-activated GPCR genes, four were GATA-1-activated, and only Gpr65 expression resembled Gata2. Contrasting with the paradigm...

  15. A compact design for the Josephson mixer: The lumped element circuit

    Pillet, J.-D.; Flurin, E.; Mallet, F.; Huard, B.
    International audience

  16. A compact design for the Josephson mixer: The lumped element circuit

    Pillet, J.-D.; Flurin, E.; Mallet, F.; Huard, B.
    International audience

  17. Fabricación y Caracterización de dispositivos basados en Silicio Poroso sobre c-Si. Aplicaciones eléctricas, Ópticas y Térmicas.

    Fonthal Rico, Faruk
    Debido a las propiedades eléctricas y ópticas del Silicio Poroso (PS), este es un material ampliamente utilizado para el desarrollo de los dispositivos electrónicos. Por su compatibilidad con la tecnología de fabricación del Silicio, el Silicio Poroso es estudiado hoy en día en diferentes aplicaciones como: elementos activos en circuitos integrados, estructuras electro luminiscentes, dispositivos fotodetectores, dispositivos térmicos y muchas más.

    El trabajo que se ha desarrollado como tesis doctoral consiste en estudiar, fabricar y caracterizar estructuras basadas en PS en diferentes medios como el luminoso y el térmico, para 1) establecer sus diferentes comportamientos y 2) desarrollo de dispositivos basados...

  18. Fabricación y Caracterización de dispositivos basados en Silicio Poroso sobre c-Si. Aplicaciones eléctricas, Ópticas y Térmicas.

    Fonthal Rico, Faruk
    Debido a las propiedades eléctricas y ópticas del Silicio Poroso (PS), este es un material ampliamente utilizado para el desarrollo de los dispositivos electrónicos. Por su compatibilidad con la tecnología de fabricación del Silicio, el Silicio Poroso es estudiado hoy en día en diferentes aplicaciones como: elementos activos en circuitos integrados, estructuras electro luminiscentes, dispositivos fotodetectores, dispositivos térmicos y muchas más.

    El trabajo que se ha desarrollado como tesis doctoral consiste en estudiar, fabricar y caracterizar estructuras basadas en PS en diferentes medios como el luminoso y el térmico, para 1) establecer sus diferentes comportamientos y 2) desarrollo de dispositivos basados...

  19. A Column-Row-Parallel ASIC architecture for 3D wearable / portable medical ultrasonic imaging

    Chen, Kailiang
    This work presents a scalable Column-Row-Parallel ASIC architecture for 3D wearable / portable medical ultrasound. It leverages programmable electronic addressing to achieve linear scaling for both hardware interconnection and software data acquisition. A 16x16 transceiver ASIC is fabricated and flip-chip bonded to a 16x16 capacitive micromachined ultrasonic transducer (CMUT) to demonstrate the compact, low-power front-end assembly. A 3D plane-wave coherent compounding algorithm is designed for fast volume rate (62.5 volume/s), high quality 3D ultrasonic imaging. An interleaved checker board pattern with I&Q excitations is also proposed for ultrasonic harmonic imaging, reducing transmitted second harmonic distortion by over 20dB, applicable to...

  20. Estudio de modelos multifísicos para la simulación holística y concurrente de circuitos impresos

    Luna Rodríguez, J.J.
    La tesis titulada Estudio de Modelos Multifísicos para la Simulación Holística y Concurrente de Circuitos Impresos ha consistido en un análisis teórico y práctico sobre la viabilidad del modelado térmico y electromagnético, compatible con estructuras holísticas, para la simulación multifísica de circuitos impresos, que permita reproducir lo más fielmente posible su comportamiento térmico y electromagnético de forma concurrente. En este trabajo se han cubierto las siguientes etapas: 1. Estudio de diferentes modelos para la conducción, convección y radiación térmica en cuerpos simples de composición material homogénea, aplicables a la transmisión de calor unidireccional, así como su implementación en MATLAB/SIMULINK. 2. Estudio de...

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