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Nomenclatura Unesco > (22) Física > (2203) Electrónica > (2203.02) Elementos de circuitos

Categorías relacionadas:
(3307.03) Diseño de circuitos

Mostrando recursos 1 - 20 de 550

1. Broadband Macromodels for Retarded Partial Element Equivalent Circuit (rPEEC) Method - Giulio Antonini; Dirk Deschrijver; Tom Dhaene; Senior Member
Abstract—The partial element equivalent circuit (PEEC) method is, nowadays, widely used in electromagnetic compatibility and signal integrity problems in both the time and frequency domains. Similar to other integral-equation-based techniques, its time domain implementation may suffer from late time instabilities, especially when considering delays [(Lp,P,R,τ)PEEC] (rPEEC). The cause of the instabilities may be either the numerical technique used for the time integration or problems created by the discrete representation of the electromagnetic continuous problem. In this paper, we concentrate on the latter and show that frequency dispersion plays an important role and must be taken into account in order to...

2. Dinámica y Optimización de los Sistemas de Puesta a Tierra - Jiménez Lozano, Guillermo
Con la presente Tesis de Doctorado se desarrolló una metodología para el análisis de sistemas de puesta a tierra (SPT) utilizando técnicas de Optimización. El objetivo anterior se trabajó teniendo en cuenta un método de evaluación de SPT, el empleo de métodos de Optimización y su aplicación a la norma de la IEEE–80 (2013) y la realización de un experimento comparativo del método elaborado. Todo este trabajo fue posible con la elaboración de diferentes configuraciones de red caracterizadas por distintas distancias entre conductores, a través de diversas geometrías y también por varias profundidades de excavación. Además, considerando la corriente de falla...

3. Manutenção de instrumentos laboratoriais na pesquisa agropecuária. - BISCEGLI, C. I.; RABELLO, L. M.; CRUVINEL, P. E.; HERRMANN JUNIOR, P. S. P.; FERREIRA, W. S.
Elementos de circuitos passivos: dispositivos basicos. Fontes de alimentacao. Principais equipamentos eletronicos para a manutencao de instrumentos laboratoriais da pesquisa agropecuaria. Elementos de circuitos ativos: dispositivos semicondutores. Amplificadores operacionais, microprocessadores e arquitetura de computadores em instrumentacao. Instrumentos opticos. Como realizar a manutencao em microscopios, balancas analogicas, estufas, B.O.D, pH-metros, colorimetros, balancas eletronicas, fotometros de chama e porometros. Termos tecnicos em instrumentacao.

4. Design and Construction of a Brain-Like Computer: A New Class of Frequency-Fractal Computing Using Wireless Communication in a Supramolecular Organic, Inorganic System - Subrata Ghosh; Krishna Aswani; Surabhi Singh; Satyajit Sahu; Daisuke Fujita; Anirban Bandyopadhyay
Here, we introduce a new class of computer which does not use any circuit or logic gate. In fact, no program needs to be written: it learns by itself and writes its own program to solve a problem. Gödel’s incompleteness argument is explored here to devise an engine where an astronomically large number of “if-then” arguments are allowed to grow by self-assembly, based on the basic set of arguments written in the system, thus, we explore the beyond Turing path of computing but following a fundamentally different route adopted in the last half-a-century old non-Turing adventures. Our hardware is a...

5. The Bandwidths of a Matrix. A Survey of Algorithms - Mafteiu-Scai Liviu Octavian
The bandwidth, average bandwidth, envelope, profile and antibandwidth of the matrices have been the subjects of study for at least 45 years. These problems have generated considerable interest over the years because of them practical relevance in areas like: solving the system of equations, finite element methods, circuit design, hypertext layout, chemical kinetics, numerical geophysics etc. In this paper a brief description of these problems are made in terms of their definitions, followed by a comparative study of them, using both approaches: matrix geometry and graph theory. Time evolution of the corresponding algorithms as well as a short description of...

6. A Linear CMOS Transconductance Element - Bhaskar Gopalan
A novel circuit technique for realizing a linear CMOS transconductance element is proposed. The present circuit is an alternative to that of conventional source-coupled differential pair (SCDP) and the circuit discussed has superior linearity than the SCDP for a wide range of input differential voltage. The SPICE results using BSIM3v3.1 model are used to verify theoretical predictions. The results show close agreement between predicted behavior and simulated performance. The simulated results on Total Harmonic Distortion (THD) show that the proposed circuit is better than the SCDP for a wide range of input differential voltage. An example circuit, a second order...

7. Electronically Tunable Multi-Terminal Floating Nullor and Its Applications - W. Tangsrirat
A realization scheme of an electronically tun- able multi-terminal floating nullor (ET-MTFN) is de- scribed in this paper. The proposed circuit mainly employs a transconductance amplifier, an improved translinear cell, two complementary current mirrors with variable current gain and improved Wilson current mirrors, which provide an electronic tuning of the current gain. The va- lidity of the performance of the scheme is verified through PSPICE simulation results. Example applications employing the proposed ET-MTFN as an active element demonstrate that the circuit properties can be varied by electronic means.

8. Automatização de um destilador d'água - Neves Carlos A.; Gutz Ivano G. R.; Lago Claudimir L. do
A simple and inexpensive device to automate a water distilling apparatus is shown. It is composed by a magnetic floater placed in the water reservoir and a level control unit, which acts over the heating element circuit. In order to provide water saving, an electromagnetic valve is inserted in the water supply inlet. Some suggestions for the adaptation to other types of equipment are also offered.

9. Performance Analysis and Simulation of a Novel Brushless Double Rotor Machine for Power-Split HEV Applications - Jingang Bai; Quanbin Zhao; Jing Zhao; Chengde Tong; Qian Wu; Ping Zheng
A new type of brushless double rotor machine (BDRM) is proposed in this paper. The BDRM is an important component in compound-structure permanent-magnet synchronous machine (CS-PMSM) systems, which are promising for power-split hybrid electric vehicle (HEV) applications. The BDRM can realize the speed adjustment between claw-pole rotor and permanent-magnet rotor without brushes and slip rings. The structural characteristics of the BDRM are described and its magnetic circuit model is built. Reactance parameters of the BDRM are deduced by an analytical method. It is found that the size characteristics of the BDRM are different from those of conventional machines. The new...

In this paper the authors shows the research made for improving high-power audio speaker devices performance using permanent NdFeB magnets special technology. Magnetic losses inside these audio devices are due to mechanical system frictions and to thermal effect of Joules eddy currents. In this regard, by special technology, were made conical surfaces at top plate and center pin. Analysing results obtained by modelling the magnetic circuit finite element method using electronic software package,was measured increase efficiency by over 10 %, from 1,136T to13T.

11. Tendencias y situación actual de las bibliotecas y unidades de información en América Latina
Trends and present situation of the Libraries and Information Units
- Gloria Ponjuán Dante

Síntese do panorama geral das bibliotecas nacionais, públicas, escolares, universitárias e unidades de informação nos 18 países componentes da América Latina. Analisa o contexto profissional dos bibliotecários atuantes nessas instituições, bem como os elementos integrantes do circuito da informação eletrônica: edição, copyright, conservação. Conclui que o profissional da informação tem que aplicar métodos e ferramentas de gestão para uma atuação eficaz.

12. Estudio mediante EIS de la respuesta electroquímica de la aleación AA5083 frente a señales DC anódicas - Aballe, A.; Bethencourt, M.; Botana, F. J.; Marcos, M.; Pérez-Mariscal, J.; Rodríguez-Chacón, M. A.
Electrochemical Impedance Spectroscopy (EIS) has been applied to characterise the behaviour of AA5083 alloy samples under anodic polarisation in a 3.5 % NaCl solution. EIS spectra were obtained at different DC potentials falling within the passivity range characteristic of the anodic polarisation branch of this alloy in the cited corrosive environment. Three different types of electrochemical response, with specific features in the corresponding Nyquist diagrams, were observed within the potential range covered in this study. The different type of spectra have been fitted with equivalent circuits. The evolution of the values of the different elements in the circuits as a...

13. Utilizing Symbolic Programming in Analog Circuit Synthesis of Arbitrary Rational Transfer Functions - Amjad Fuad Hajjar
The employment of symbolic programming in analog circuit design for system interfaces is proposed. Given a rational transfer function with a set of specifications and constraints, one may autonomously synthesize it into an analog circuit. First, a classification of the target transfer function polynomials into 14 classes is performed. The classes include both stable and unstable functions as required. A symbolic exhaustive search algorithm based on a circuit configuration under investigation is then conducted where a polynomial in hand is to be identified. For illustration purposes, a set of complete design equations for the primary rational transfer functions is obtained targeting all classes of second order...

14. Steady-state solution of the PTC thermistor problem using a quadratic spline finite element method - Bahadir A. R.

The problem of heat transfer in a Positive Temperature Coefficient (PTC) thermistor, which may form one element of an electric circuit, is solved numerically by a finite element method. The approach used is based on Galerkin finite element using quadratic splines as shape functions. The resulting system of ordinary differential equations is solved by the finite difference method. Comparison is made with numerical and analytical solutions and the accuracy of the computed solutions indicates that the method is well suited for the solution of the PTC thermistor problem.

15. The application conditions of the compact modified method of curve fitting for parametric synthesis of switched-capacitor networks - M. E. Artemenko; A. I. Rybin; M. S. Kumsiya

The topological and algebraic conditions for formation of ARC-prototype state equation were obtained to diagnose the possibility of application the compact modified method of curve fitting for parametric synthesis of SC-filter directly on its circuit or element’s connection matrix. The formal mathematical apparatus of forming the ARC-prototype’s compact equation of electric equilibrium on the element’s connection matrix was developed, which allows to reduce the dimension of the synthesized filter to the number of prototype’s capacitors. The relations to account nonideal parameters of operational amplifiers for the prototype’s compact equation of electric equilibrium were obtained, which improve the accuracy of parametric synthesis of switched-capacitor...

No ramo de papel e celulose os efluentes são um dos principais problemas e o consumo de água é crítico. Os circuitos internos estão sendo fechados e as fontes de contaminação precisam ser conhecidas. Uma das fontes de contaminação destes efluentes são os minerais da madeira, matéria-prima neste tipo de indústria. Neste trabalho foi avaliada a quantidade de alumínio, cálcio, cobre, ferro, potássio, magnésio, manganês, sódio, níquel e silício em madeiras de cinco espécies florestais, plantadas na região de Guaíba, RS, compreendendo Acacia mearnsii, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus saligna. As amostras de madeira foram tratadas com digestão...

17. Automated parametrical antenna modelling for ambient assisted living applications - R. Kazemzadeh; W. John; W. Mathis
In this paper a parametric modeling technique for a fast polynomial extraction of the physically relevant parameters of inductively coupled RFID/NFC (radio frequency identification/near field communication) antennas is presented. The polynomial model equations are obtained by means of a three-step procedure: first, full Partial Element Equivalent Circuit (PEEC) antenna models are determined by means of a number of parametric simulations within the input parameter range of a certain antenna class. Based on these models, the RLC antenna parameters are extracted in a subsequent model reduction step. Employing these parameters, polynomial equations describing the antenna parameter with respect to (w.r.t.) the overall antenna input parameter range are extracted by means of...

18. Design of Universal Shift Register Using Reversible Logic - Md. Hasanuzzaman; Indrani Manda; Md. Selim Al Mamun
Reversible sequential circuits are considered the significant memory block for their ultra-low power consumption. Universal shift register is an important memory element of the sequential circuit family. In this paper we proposed efficient design of reversible universal shift register that is optimized in terms of quantum cost, delay and garbage outputs. Appropriate theorems and lemmas are presented to clarify the proposed designs and establish its efficiency.

19. Hirator na osnovi helikonovoho rezonatora [Hirator based on helicon resonator] - Vol. S. Vuntesmeri
The possibility of implementing hiratora a circuit element in the meter and decameter wavelengths using passive device - nevzayemnoho transformer based helikonovoho resonator.

20. Network modelling with Brune's synthesis - F. Mukhtar; Y. Kuznetsov; P. Russer
Network modelling of general, lossy or lossless, one-port and symmetric two-port passive electromagnetic structures in systematic manner is presented. Rational function representation of the numerical data of Z- or Y-parameters is obtained with the use of Vector Fitting procedure. A systematic strategy for obtaining equivalent lumped element circuit from the rational function, applying Brune's circuit synthesis, is also presented.

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