Global ETD Search

11	Development of a multipoint temperature measurement system based on resistance network and its application to solid oxide fuel cells / 抵抗ネットワークに基づく多点温度計測システムの開発とその固体酸化物形燃料電池への応用 Mao, Runze 26 September 2022 (has links) 京都大学 / 新制・課程博士 / 博士(工学) / 甲第24227号 / 工博第5055号 / 新制\|\|工\|\|1789(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授岩井裕, 教授中部主敬, 教授黒瀬良一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM Multipoint temperature measurement Resistance temperature detectors Grid-shape electrical circuit Solid oxide fuel cells Artificial neural network 500
12	Corrosão de aços inoxidáveis empregando mapas de impedância / Corrosion of stainless steels employing impedance maps Glauber de Souza Melengate 31 March 2014 (has links) Os aços inoxidáveis correspondem a aços com diferenças de composição e microestrutura. Desta forma, o comportamento em corrosão é consequentemente diferente. Para avaliar este aspecto, aços com PREN variando de aproximadamente 11 a 35% foram analisados por curvas de polarização. A motivação principal desse trabalho foi avaliar o comportamento de cada aço inoxidável com uso de diferentes técnicas (impedância eletroquímica e circuitos elétricos equivalentes) e também na nova técnica de mapas de impedância, da influência do PREN na corrosão em meio de 3,5% NaCl a 25C. A partir dessas curvas, os potenciais de pites e de densidade de corrente de corrosão foram obtidos. Além disto, foram empregados mapas de diagrama de impedância eletroquímica para visualizar o efeito do potencial aplicado, desde o potencial catódico até além do potencial de pite desses aços. Pôde-se observar que o módulo de impedância se reduz abruptamente quando surge o pite. Ademais, há uma alteração do ângulo característico para frequências da ordem de 1 kHz. Para dois aços inoxidáveis, UNS S30400 e UNS S31600, foram utilizados os diagramas de impedância obtidos dos mapas e estimados a evolução dos parâmetros relacionados a um circuito elétrico equivalente para potenciais aplicados. / Stainless steels account for steels with different in composition and microstructure. Thus, the corrosion behavior is consequently different. To assess this, steels with PREN ranging from 11% to 35% were analyzed by polarization curves. The main motivation of this work was the evaluation the behavior of each stainless steel via different techniques (electrochemical impedance spectroscopy and equivalent electrical circuit), as well as the use of the new technique of impedance maps, on the influence of PREN on the corrosion in 3.5% NaCl at 25C. From these curves, the pitting potential and corrosion current density were obtained. In addition, maps were used diagram electrochemical impedance to view the effect of the applied potential, from the cathodic potential up to the pitting potential of these steels. It can be observed that the modulus of impedance decays abruptly when pitting take place. Moreover, there is a change in the angle characteristic for frequencies in the order of 1 kHz. For two stainless steels, i.e,. UNS S30400 and UNS S31600, the diagrams of maps were used to monitoring the evolution parameters related to an electrical equivalent circuit for the applied potentials. Curvas de polarização Mapas de impedância Circuito elétrico equivalente Aço inoxidável Corrosão Corrosão e anticorrosivos Stainless steels Polarization curves Impedance maps Equivalent electrical circuit FISICA ATOMICA E MOLECULAR
13	Smart Case for Remote Radio Kit Östlund, Emil January 2019 (has links) The thesis aims to develop a prototype for a Smart Case for Remote Radio Kits at the department of Demo & Event at Ericsson in Kista.The smart case consists of a mechanical structure (the case itself with ) and an electronic system that includes a temperature sensor, a LCD display showing the temperature, a GPS (global positioning system) module for positioning the case, a GSM (Global System for Mobile Communications) module and a microcontroller Arduino UNO. The Case is modelled in 3D with the help of CAD software and then printed with a 3D printer. A down-scaled prototype is built with the help of the 3D printer and the 2D drawing will be used when the full scaled model is produced. The Arduino UNO handles temperature sensor and GPS measurements, LCD display, and the transmission of measurement data using GSM module via text message (SMS) to a cell phone or to a server over the Internet. The projected ended up with all the drawings and models finished for the Case as well as the implementation of down-scaled prototypes. The electrical system was tested and finished individually. But the complete system cannot be assembled inside the Case due to the time limitation. This means that the project can be further extended, where a full scale model can be developed and the electrical control system can be assembled together and mounted inside the Case. CAD LTE IoT Signal processing Data communication Data transmission 3D printing Soldering Electrical circuit schematics simulations Arduino Software Hardware Elektroteknik och elektronik
14	Corrosão de aços inoxidáveis empregando mapas de impedância / Corrosion of stainless steels employing impedance maps Glauber de Souza Melengate 31 March 2014 (has links) Os aços inoxidáveis correspondem a aços com diferenças de composição e microestrutura. Desta forma, o comportamento em corrosão é consequentemente diferente. Para avaliar este aspecto, aços com PREN variando de aproximadamente 11 a 35% foram analisados por curvas de polarização. A motivação principal desse trabalho foi avaliar o comportamento de cada aço inoxidável com uso de diferentes técnicas (impedância eletroquímica e circuitos elétricos equivalentes) e também na nova técnica de mapas de impedância, da influência do PREN na corrosão em meio de 3,5% NaCl a 25C. A partir dessas curvas, os potenciais de pites e de densidade de corrente de corrosão foram obtidos. Além disto, foram empregados mapas de diagrama de impedância eletroquímica para visualizar o efeito do potencial aplicado, desde o potencial catódico até além do potencial de pite desses aços. Pôde-se observar que o módulo de impedância se reduz abruptamente quando surge o pite. Ademais, há uma alteração do ângulo característico para frequências da ordem de 1 kHz. Para dois aços inoxidáveis, UNS S30400 e UNS S31600, foram utilizados os diagramas de impedância obtidos dos mapas e estimados a evolução dos parâmetros relacionados a um circuito elétrico equivalente para potenciais aplicados. / Stainless steels account for steels with different in composition and microstructure. Thus, the corrosion behavior is consequently different. To assess this, steels with PREN ranging from 11% to 35% were analyzed by polarization curves. The main motivation of this work was the evaluation the behavior of each stainless steel via different techniques (electrochemical impedance spectroscopy and equivalent electrical circuit), as well as the use of the new technique of impedance maps, on the influence of PREN on the corrosion in 3.5% NaCl at 25C. From these curves, the pitting potential and corrosion current density were obtained. In addition, maps were used diagram electrochemical impedance to view the effect of the applied potential, from the cathodic potential up to the pitting potential of these steels. It can be observed that the modulus of impedance decays abruptly when pitting take place. Moreover, there is a change in the angle characteristic for frequencies in the order of 1 kHz. For two stainless steels, i.e,. UNS S30400 and UNS S31600, the diagrams of maps were used to monitoring the evolution parameters related to an electrical equivalent circuit for the applied potentials. Curvas de polarização Mapas de impedância Circuito elétrico equivalente Aço inoxidável Corrosão Corrosão e anticorrosivos Stainless steels Polarization curves Impedance maps Equivalent electrical circuit FISICA ATOMICA E MOLECULAR
15	Terminál pro testování datových přenosů vozidel MHD / Terminal for testing of data communication of public transport vehicles Fiala, Michal January 2014 (has links) This term paper deals with subject of wireless communication of city rail transport cars. In this paper are described individual modules for transmission and receiving of data containing communication between city rail transport cars and measures of siding switches. Then there are discussed possibilities of design of system for testing functionality of transmitting and receiving modules and the system is consequently designed. There are also described communication principles and protocol used for wireless communication and MODBUS protocol used for communication over RS-485 serial line. In the end was the system manufactured, completed and equipped with necessary software.
16	Teplotní profil výkonového spínacího přístroje nízkého napětí pro různé provozní stavy / The temperature profile of the power switching device of low voltage for different operating conditions Mejzlík, Tomáš January 2015 (has links) The heat generated in a circuit breaker can be transmitted in two ways: Either through metal parts of current path to conductors outside of device or through plastic parts or air of chassis. The accuracy of the simulation depends on the accuracy of the 3D model and all his parts and it also depends on precise definition of materials with precise definition of electrical and thermal parameters. Electrical circuit breaker has various source of the heat which results in raising temperature of the device above the level of environment. Heat sources are: 1) Joule’s loss of the circuit breaker current path. 2) Heat loss in a bimetal, which is used for thermal release. 3) Resistivity of contacts. This thesis deals with static state of thermal analysis so the sources do not include transient heat source for switching OFF and switching ON. Electrical circuit breakers are made in smaller and smaller forms however their electrical parameters are not decreasing with size. There is logical conclusion that there is more heat on the same unit size which makes thermal analysis of circuit breaker one of the most important part of development.
17	Frekvenční charakteristiky / Frequency Responses Urbánek, Radim January 2007 (has links) The aim of this MSc Thesis is to create a system for automatic generation of frequency characteristics of electrical circuits. These circuits are described by differential equations. A special simulator of RLC circuit has been created and frequence response, vector diagram can be generated. This system has been mainly suggested for application in education. The process of solving differential equations is based on the Taylor method. Systems in general is the theoretical part of this project. Different definitions of systems their divission ,basic phenomenons and mathematical devices are described there. Next chapter deals with the mathematical devices for solving differential equations which makes the basis for description of phenomenons in these systems. There are also systems TKSL and TKSL/C. In the next chapter I was investigaty the analyze of vector diagrams for simple and more difficult circuits. I have found a solution for actual circuit by this technique. The last chapter is devoted to the frequency characteristics and descriptions of simulation program for generation the frequency characteristics.
18	Nanolithography on thin films using heated atomic force microscope cantilevers Saxena, Shubham 01 November 2006 (has links) Nanotechnology is expected to play a major role in many technology areas including electronics, materials, and defense. One of the most popular tools for nanoscale surface analysis is the atomic force microscope (AFM). AFM can be used for surface manipulation along with surface imaging. The primary motivation for this research is to demonstrate AFM-based lithography on thin films using cantilevers with integrated heaters. These thermal cantilevers can control the temperature at the end of the tip, and hence they can be used for local in-situ thermal analysis. This research directly addresses applications like nanoscale electrical circuit fabrication/repair and thermal analysis of thin-films. In this study, an investigation was performed on two thin-film materials. One of them is co-polycarbonate, a variant of a polymer named polycarbonate, and the other is an energetic material called pentaerythritol tetranitrate (PETN). Experimental methods involved in the lithography process are discussed, and the results of lithographic experiments performed on co-polycarbonate and PETN are reported. Effects of dominant parameters during lithography experiments like time, temperature, and force are investigated. Results of simulation of the interface temperature between thermal cantilever tip and thin film surface, at the beginning of the lithography process, are also reported. Characterization Deflection Setpoint Grain rearrangement Array Precise positioning Metrology Explosion Explosives Data storage Material Image processing Slow scan disabled Temperature Tip Local In-situ Nanoscale Electrical circuit fabrication Repair Co-polycarbonate Polymers Polycarbonates Energetic materials PETN Simulation Interface Nano-manufacturing Experiment Calibration Raman Frequency Deflagration Decomposition Detonation Build up Pile-up End capped End capping Cross linked Cross-linked Conductivity Microscale MEMS Microcantilever NEMS DPN tDPN Silicon Glass Peak InVOLS Manipulation AFM Atomic force microscope Defense Nanoscale Surface Stiffness Force Scan size Thermal cantilevers Imaging Lithography Nanolithography Thin films Cantilevers Heaters Technology Nanotechnology Scan velocity Scan rate Bake Anneal Pentaerythritol tetranitrate Thin films Thermal properties Atomic force microscopy Microlithography Nanotechnology Surfaces (Technology) Analysis
19	Měření parametrů piezoelektrických materiálů / Piezoceramics Measurements Fialka, Jiří January 2009 (has links) The master’s thesis deals with the piezoelectric coefficients, the resonance frequency and especially the piezoelectric constants verification. With the assistance of several devices, for instance LCR-meter HIOKI 3532, impedance analyzer Agilent 4294A and LCR-meter Agilent E4980A, the resonance and the anti-resonance frequencies as well as impedance and capacitance of samples are measured. The paper opens with the theory of the piezoelectric phenomenon and the difference between direct and indirect piezoelectric phenomenon, it also describes the basic behaviour of a piezoelectric ceramic element during mechanical straining or applied voltage. Further, the paper concerns the description of various piezoelectric constants and their calculations. Subsequent part of the paper is devoted to the temperature dependence of the main piezoelectric parameters of PZT ceramics. The materials coefficients are delineated as a function of temperature of the piezoelectric charge coefficients dij, relative permittivity r, electromechanical coupling factor kij and frequency constants Ni. One of the chapters also determines the piezoelectric charge constant d33 of PZT ceramics by laser interferometer and compares it with the value measured by resonance methods. The surface displacement was measured by a single-beam interferometer Polytec OFV-5000. The results of measurements of piezoelectric charge coefficients d33 acquired by the first and the second method are identical. The last section of the paper is focused on different methods of experimental studies on the characteristics of heat transfer by diffusing heat through conduction between the silver-plated surface of cylinder made of PZT ceramics. The effect on the resonance and the anti-resonance frequencies is monitored. There after, the real heat, determined by thermo camera and the physical model of heat transfer created in program COMSOL Multiphysics, is analysed.

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