Mostrando recursos 1 - 20 de 700

  1. Aplicación del método de los elementos finitos en 3D al diseño del circuito magnético de un transformador de potencia y comparación con el diseño basado en herramientas en 2D

    [ES] El objetivo de este trabajo es aplicar el método de los elementos finitos en 3D al proceso de diseño de un transformador para evaluar la viabilidad práctica de la utilización del análisis 3D así como las ventajas e inconvenientes respecto del análisis basado en herramientas 2D, utilizado actualmente por la mayoría de los fabricantes. Los estudios propuestos se basarán en la simulación numérica, utilizando softwares específicos para el análisis de campos magnéticos. Se partirá de prototipos de transformadores trifásicos disponibles en el laboratorio. Estos transformadores serán analizados utilizando las herramientas 2D y 3D, y los resultados se compararán...

  2. Acoustic impact of the glottal chink on the production of fricatives: A numerical study

    Elie, Benjamin; Laprie, Yves
    The paper presents a numerical study about the acoustic impact of the glottal chink opening on the production of fricatives. Sustained fricatives are simulated by using classic lumped circuit element methods to compute the propagation of the acoustic wave along the vocal tract. A recent glottis model is connected to the wave solver to simulate a partial abduction of the vocal folds during their self-oscillating cycles. Area functions of fricatives at the three places of articulation of French (palato-alveolar, alveolar, and labiodental) have been extracted from static MRI acquisitions. Simulations highlight the existence of three distinct regimes, named A, B,...

  3. Análisis de circuitos con Matlab

    Lobo Sánchez, Belén
    En la actualidad y desde hace algunos años, muchas carreras y módulos de grado superior se basan en la electrónica. En algunos institutos hay asignaturas que hacen una breve introducción a este mundo como es el caso de Tecnología u optativas como Electrotecnia, pero no llegan a profundizar mucho, sólo dan una breve introducción de conceptos básicos. Muchas veces resulta tedioso el resolver los circuitos y más cuando no se sabe si el resultado está bien o no ya que se plantean muchas ecuaciones con muchas incógnitas y es relativamente fácil equivocarse en un número. Esto hace que el análisis no haya...

  4. Dimensionado de un pequeño aerogenerador para uso domestico en el término municipal de Aielo de Malferit (Valencia)

    [ES] Este trabajo recoge el diseño de un pequeño aerogenerador para uso doméstico en una vivienda unifamiliar situada en el Término Municipal de Aielo de Malferit (Valencia). Se desarrolla el proceso de diseño y dimensionado del aerogenerador, así como una valoración estimada de fabricación del mismo determinando la energía estimada que producirá durante un año. Para desarrollar el diseño, es necesario conocer en primer lugar, la distribución de los vientos a lo largo del año. De ahí, que se haya adquirido e instalado una pequeña estación meteorológica que registra la velocidad del viento en el lugar de estudio. Resaltar la limitación...

  5. Simulación de operación de una central nuclear con el simulador gráfico interactivo: LOCA en rama fría en BOL, MOL y EOL

    Penche Alonso, Marta
    La energía nuclear convencional se basa en reacciones de fisión producidas cuando los átomos de uranio absorben neutrones. Se tratan de reacciones autosostenidas en el combustible del reactor nuclear. Este trabajo se enmarca dentro del campo de la seguridad nuclear, estudiando, mediante simulaciones, el desarrollo del accidente base de diseño LOCA. En la seguridad de una central nuclear hay varios niveles: - Primer nivel: la prevención de accidentes. - Segundo nivel: el control de la operación anormal y la detección de fallos. Protección contra accidentes. - Tercer nivel: La contención múltiple de la radiactividad mediante barreras pasivas. Mitigación de accidentes. Este trabajo se realiza en el...

  6. Hybrid Simulation Approach on MEMS Piezoresistive Microcantilever Sensor for Biosensing Applications ROSMINAZUIN AB. RAHIM1,a, BADARIAH BAIS2,b and BURHANUDDIN

    Abstract. This paper uses a hybrid simulation approach in CoventorWare design environment which combines finite element analysis and circuit simulation modeling to obtain the optimal performance of piezoresistive microcantilever sensor. A 250 µm x 100 µm x 1 µm SiO2 cantilever integrated with 0.2 µm thick Si piezoresistor were used in this study. A finite element analysis on piezoresistive microcantilever sensor was conducted in CoventorWare Analyzer environment which incorporates MemMech and MemPZR modules. The sensor sensitivity was obtained by measuring resistivity changes in piezoresistive material in response to surface stress changes of microcantilever. The simulation results were later integrated with...

  7. Towards the Complete Relational Graph of Fundamental Circuit Elements*

    Abstract: A complete and harmonized fundamental circuit relational graph with four linear and four memory elements is constructed based on newly defined elements, which provides a guide to developing novel circuit functionalities in the future. In addition to resistor, capacitor and inductor which are defined in terms of a linear relationship between the charge q, the current i, the voltage v, and the magnetic flux , Chua proposed in 1971 the fourth linear circuit element to directly relate and q. A non-linear resistive device defined in memory i-v relation and dubbed memristor, was later attributed to such an element and...


    Johannes A Russer; Technische Universität München; Sidina Wane; D. Bajon; Peter Russer; Technische Universität München
    Abstract—In this paper we propose the usage of bond wires as antennas for chip-to-chip communications. A wireless bond-wire communication link is designed and investigated experimentally. A lumped element two-port equivalent circuit model is estab-lished using a system-identification-based combined Bartlett-Brune approach. I.

  9. 1 Purely Mechanical Memristors and the Missing Memristor

    Sascha Vongehra
    This work is suppressed since 2010 and led to established scientists to be banned on the arXiv. We thank VIXRA for making critical work like this still available to relatively uncorrupted parts of the scientific community. We define a mechanical analog to the electrical basic circuit element M = dφ/dQ, the ideal mechanical memristance M = dp/dx, p being momentum. A never before described mechanical memory resistor M(x) is independent of velocity v and has a pinched hysteretic loop that collapses at high frequency in the v versus p plot: a perfect memristor. However, its memristance does not crucially involve...

  10. Chairperson Date Approved

    Lakshmi Anusha Kosuru
    Ultra High Frequency Radio Frequency Identification (UHF RFID) technology has gained prominence in recent years. It is being deployed extensively in supply chain and asset tracking by retailers to better control their inventory. The main drawback of UHF RFID tag antenna is that it is sensitive to the environment in which it operates. The performance of the tag degrades when placed on conductive or dielectric objects. While RFID tags near metal have been extensively evaluated in the literature, tags on and in dielectric media have received less scrutiny and rigorous evaluation. In this thesis, we develop a rigorous theoretical model...

  11. Tailoring piezoresistive sensitivity of multilayer carbon nanotube composite strain sensors

    K. J. Loh; J. P. Lynch; B. S. Shim; N. A. Kotov
    ABSTRACT: In recent years, carbon nanotubes have been utilized for a variety of applications, including nanoelectronics and various types of sensors. In particular, researchers have sought to take advantage of the superior electrical properties of carbon nanotubes for fabricating novel strain sensors. This article presents a single-walled carbon nanotube (SWNT)-polyelectrolyte (PE) composite thin film strain sensor fabricated with a layer-by-layer (LbL) process. Optimization of bulk SWNT-PE strain sensor properties is achieved by varying various LbL fabrication parameters, followed by characterization of strain-sensing electromechanical responses. A resistor and capacitor (RC)-circuit model is proposed and validated with electrical impedance spectroscopy to fit...

  12. G.K.: Sinoatrial reciprocation in the isolated rabbit heart. Circ Res

    Jaok Han; Ph. D; Anna Mae Malozzi; Gordon K. Moe; Ph. D
    Reciprocal beats between sinus node and atrium were studied in isolated rabbit heart tissue by microelectrode techniques. Early premature atrial responses which entered the sinus node frequently emerged to re-excite the atrium as "echoes. " When the premature atrial beats discharged some but not all nodal areas, the atrial echoes, in turn, appeared to re-enter the sinus node. Repetitive reciprocation involving the sino-atrial circuit was occasionally observed. Anatomic and temporal patterns of excitation at multiple recording sites suggest that "entrance " block and slow conduction of premature impulses within the sinus node may explain the observed reciprocation. The results support...

  13. Fig

    Downloadequency. The circuit element known as constant-phase elemenS0013-4651(98)08-014-8 CCC: $7. In the case of oxide-semiconductor-based chemical gas sensors, the dc measurements do not give information on the mechanism of processes. However, the ac method offers a powerful tool to exam-ine the nature of the conduction processes and the mechanism of the gas/solid interactions. b-Ga2O3 single-crystal1 and polycrystalline2,3 samples were examined in the medium-frequency range. Authors could distinguish the electronic and ionic conduction as a function of temperature. In this work it is shown that starting from low frequencies (10 mHz), impedance spectroscopy is suitable for distinguishing the effect of gas...

  14. 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...

  15. Proposal for Memristors

    Blaise Mouttet; Memristor Reductio Ad; Hplabs “found The
    The memristor is the “4th fundamental circuit element”

  16. An Adaptive Impedance Matching System for Mobile Communication Antennas

    Ichirou Ida; Jun-ichi Takada; Takeshi Toda; Yasuyuki Oishi
    An adaptive impedance matching system is proposed. This system employs only a simple algorithm for convergence, therefore does not need any complicated mathematical formulation for modeling of the system itself as well as its nonlinear control elements. Also the proposed system utilizes only simple digital circuits for timing generation and basic analog circuits. Even with a small range of capacitance for control element in a matching circuit, the improvement in the mismatch is observed by 2-3dB over an impedance matching circuit with fixed capacitances. 1.


    S. H. Zainud-deen; S. I. El-doda; K. H. Awadalla; H. A. Sharshar
    Abstract—Finite-Difference Time Domain (FDTD) is used to calculate the input impedance of the cylindrical dielectric resonator (DRA) antenna with different dimensions. A lumped- element circuit model for the input impedance calculation is proposed. The genetic algorithm is used to calculate the elements of the equivalent circuit. The Model-Based Parameter Estimation (MBPE) technique is used to find the variation of each element in the equivalent circuit with varying the physical dimensions of the antenna. The use of this method reduces the time required for calculating the input impedance of the cylindrical DRA in each variation of the antenna dimension. 1.

  18. Contributions and reflections to the study of stability and oscillation of active antennas

    Parra Cerrada, Ángel
    This thesis was carried out in the DIEMAG Group and TSC department of ETSI y Sistemas de Telecomunicación from Universidad Politécnica de Madrid. Its title is “Contributions and Reflections to the Study of Stability and Oscillation of Active Antennas” and it has been developed by Angel Parra Cerrada, Electrical Engineer MSc, under the supervision of Prof. Vicente Gonzalez Posadas, PhD and Prof. Jose Luis Jimenez Martin, PhD. The current interest on active antennas is very important, mainly on small antennas and integrated antennas. The patch antennas are maybe the type of integrated antennas more used at present designs. The design...

  19. Simplified Modeling for Impedance-based Health Monitoring

    Daniel M. Peairs; Gyuhae Park; Daniel J. Inman
    Abstract. A new model of impedance-based structural health monitoring (SHM) using the spectral element method (SEM) and electric circuit analysis has been developed. This model provides additional information for more accurately identifying and locating damage and in designing the SHM system. Complex functions of the SHM system such as estimation of remaining life are also made possible with the use of the model. The circuit analysis can be applied to any type of structural model. However, since impedance-based SHM relies on high frequency excitation of the structure using piezoelectric patches, finite element modeling may not be applicable and instead the...

  20. B4 ECS Electrochemistry Letters, 4 (7) B4-B7 (2015) 2162-8726/2015/4(7)/B4/4/$33.00 © The Electrochemical Society Impedance Biosensor Utilizing a Si Substrate Deposited by Wet Methods

    Bamidele D. Falola; Rajeswaran Radhakrishnan; Ian I. Sunia
    formic acid, followed by antibody immobilization. The impedance response of the sensor electrode to increasing concentrations of peanut protein Ara h 1, a common food allergen, can be fit to an equivalent circuit containing three RC loops. The circuit element most sensitive to antigen binding is the charge transfer resistance, yielding a detection limit of 4 ng/ml.

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