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Development of laboratory samples for wireless transmission of electric power based on the magnetic induction
Kopečný, David ; Štěpánek, Jaroslav (referee) ; Krbal, Michal (advisor)
The aim of the thesis is to collect the information about wireless transmission by using magnetic induction and about the current solutions of wireless applications in practice. The thesis includes theoretical basis and information about the current state of wireless power applications. This thesis is also focused on physical principle and draft of possible technical solution. On top of that, it also contains the information from some legislative and hygienic regulations. The second aim is draft of laboratory equipment on the base of gained information and its implementation for purpose of teaching and measuring. For this part was chosen topology of circuit and the specifications of resonance circuits. It resulted in producing a preparation, which consists of the exciter, primary circuit, secondary circuit and a module for measuring. The third aim is to take a measurement on this product and evaluation of characteristic from point of view of efficiency. Measured data were integrated into characteristics. The efficiency of transfer was measured depending on distance and used load. At the same time was also observed work frequency of product. Furthemore, another laboratory product was measured, in which was reached the efficiency more than 51%. The thesis is divided into four main chapters, which can be thematically named as follows: the information, the theory, the draft and the measurement. The first two chapters deal with the theory and characterization of technologies of already applied systems mainly from transport. The following two chapters contain the description of proposal of the product and the very measuring of the efficiency.
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Non-Linear Electro-Ultrasonic Spectroscopy of Resistive Materials
Tofel, Pavel ; Koktavý, Bohumil (referee) ; Smulko, Janusz (referee) ; Šikula, Josef (advisor)
Elektro-ultrazvuková spektroskopie je založena na interakci dvou signálů, elektrického střídavého signálu s frekvencí fE a ultrazvukového signálu s frekvencí fU. Ultrazvukový signál mění vzdálenost mezi vodivými zrny ve vzorku a tím mění jeho celkový elektrický odpor R. Změna odporu R je proměnná s frekvencí ultrazvukového signálu fU. Vzorek, který obsahuje mnoho defektů ve své struktuře, vykazuje vysokou změnu odporu R v porovnání se vzorkem bez defektů při stejné hodnotě ultrazvukového a elektrického signálu. V disertační práci je popsána elektro-ultrazvuková metoda na tlustovrstvých rezistorech, hořčíkových slitinách, monokrystalech Si a CdTe, varistorech a také jeden z prvních pokusů aplikace elektro-ultrazvukové spektroskopie na horninové vzorky a tak diagnostikovat jejich stav poškození. V našem případě byl proměřen vzorek žuly. Jelikož se jedná o nedestruktivní metodu testování, tak má tato metoda velmi perspektivní budoucnost. Tato metoda je citlivá na všechny defekty ve vzorku. Její výhodou je, že se měří velikost signálu ne frekvenci danou rozdílem nebo součtem budících frekvencí fE a fU a tím se dá dosáhnout vysoké citlivosti. V mém případě byl vždy měřen signál na rozdílové frekvenci fi = fE-fU.
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Piezoelectric MEMS resonators for sensing applications
Klempa, Jaroslav ; Svatoš, Vojtěch (referee) ; Gablech, Imrich (advisor)
Basic principles and processes used during fabrication of microelectromechanical systems are presented in this work. This thesis is focused on material properties, deposition, lithographic and micromachining processes. Fundamental principles and applications of piezoelectric resonant structures are described as well. Final part of this work is devoted to simulation of resonant beams using FEM method in ANSYS® Workbench, practical fabrication and characterization of piezoelectric MEMS resonators.
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Cause of mechanical vibrations of Palašer synchronous motors and its removal
Pavelka, J. ; Šimek, J. ; Kobrle, P. ; Kokeš, Petr
The paper describes the procedure and the result of analysis of mechanical vibrations of mining machines at the Palašer mine in the Russian Federation. The cause of these vibrations was the change in the magnitude of the magnetic flux in the air gap. The simulations showed the possibility of eliminating these changes in\nmagnetic flux by injecting suitable voltages into the stator windings. The implementation of this injection is further described by torque variable component feed-direct compensation. Finally, oscillography records are presented before and after injection.
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Development of laboratory samples for wireless transmission of electric power based on the magnetic induction
Kopečný, David ; Štěpánek, Jaroslav (referee) ; Krbal, Michal (advisor)
The aim of the thesis is to collect the information about wireless transmission by using magnetic induction and about the current solutions of wireless applications in practice. The thesis includes theoretical basis and information about the current state of wireless power applications. This thesis is also focused on physical principle and draft of possible technical solution. On top of that, it also contains the information from some legislative and hygienic regulations. The second aim is draft of laboratory equipment on the base of gained information and its implementation for purpose of teaching and measuring. For this part was chosen topology of circuit and the specifications of resonance circuits. It resulted in producing a preparation, which consists of the exciter, primary circuit, secondary circuit and a module for measuring. The third aim is to take a measurement on this product and evaluation of characteristic from point of view of efficiency. Measured data were integrated into characteristics. The efficiency of transfer was measured depending on distance and used load. At the same time was also observed work frequency of product. Furthemore, another laboratory product was measured, in which was reached the efficiency more than 51%. The thesis is divided into four main chapters, which can be thematically named as follows: the information, the theory, the draft and the measurement. The first two chapters deal with the theory and characterization of technologies of already applied systems mainly from transport. The following two chapters contain the description of proposal of the product and the very measuring of the efficiency.
|
|
|
Piezoelectric MEMS resonators for sensing applications
Klempa, Jaroslav ; Svatoš, Vojtěch (referee) ; Gablech, Imrich (advisor)
Basic principles and processes used during fabrication of microelectromechanical systems are presented in this work. This thesis is focused on material properties, deposition, lithographic and micromachining processes. Fundamental principles and applications of piezoelectric resonant structures are described as well. Final part of this work is devoted to simulation of resonant beams using FEM method in ANSYS® Workbench, practical fabrication and characterization of piezoelectric MEMS resonators.
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Non-Linear Electro-Ultrasonic Spectroscopy of Resistive Materials
Tofel, Pavel ; Koktavý, Bohumil (referee) ; Smulko, Janusz (referee) ; Šikula, Josef (advisor)
Elektro-ultrazvuková spektroskopie je založena na interakci dvou signálů, elektrického střídavého signálu s frekvencí fE a ultrazvukového signálu s frekvencí fU. Ultrazvukový signál mění vzdálenost mezi vodivými zrny ve vzorku a tím mění jeho celkový elektrický odpor R. Změna odporu R je proměnná s frekvencí ultrazvukového signálu fU. Vzorek, který obsahuje mnoho defektů ve své struktuře, vykazuje vysokou změnu odporu R v porovnání se vzorkem bez defektů při stejné hodnotě ultrazvukového a elektrického signálu. V disertační práci je popsána elektro-ultrazvuková metoda na tlustovrstvých rezistorech, hořčíkových slitinách, monokrystalech Si a CdTe, varistorech a také jeden z prvních pokusů aplikace elektro-ultrazvukové spektroskopie na horninové vzorky a tak diagnostikovat jejich stav poškození. V našem případě byl proměřen vzorek žuly. Jelikož se jedná o nedestruktivní metodu testování, tak má tato metoda velmi perspektivní budoucnost. Tato metoda je citlivá na všechny defekty ve vzorku. Její výhodou je, že se měří velikost signálu ne frekvenci danou rozdílem nebo součtem budících frekvencí fE a fU a tím se dá dosáhnout vysoké citlivosti. V mém případě byl vždy měřen signál na rozdílové frekvenci fi = fE-fU.
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Response of quail eggs to non-destruktive impact during their storage
Strnková, J. ; Nedomová, Š. ; Trnka, Jan
During storage there are a number of changes in the egg affecting its quality and technological properties. The egg quality is mostly characterized by albumen quality during the storage. Changes during storage lead to changes in albumen´s consistency, increasing pH and changes in Haugh units. Japanese quail eggs were used for the experiment. These eggs were stored at 6 degrees C for 16 weeks. The submitted paper deals with the influence of the storage duration on the response of quail egg to non destructive impact. The response is measured using of the eggshell surface displacement using of the laser vibrometer. The change in the albumen quality significantly affects the time history of the eggshell surface and namely its representation in the frequency domain. The used method can be used for the non destructive evaluation of the egg quality during its storage.
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