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Low-noise amplifier for 145 MHz band
Pivoňka, Rostislav ; Vágner, Petr (referee) ; Baran, Ondřej (advisor)
This work contains a description of low noise amplifier (LNA) working on 145 MHz. This amplifier consists of three parts. They are input circuit, active device and output circuit. The amplifier is designed with transistor BF 998 on substrate FR4. The design and simulations are performed by means of software Ansoft Serenade. The design was completed with the help of design equations and Smith chart methods. The input of amplifier is noisy matched and output of amplifier is matched on impedance 50 ohms. The noise factor in frequency band 144 – 146 MHz is about 0,85 dB. The amplifier gain is in this band circa 16dB.
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Selective Circuits - Laboratory Experiment
Košťál, Stanislav ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
The aim of this thesis is to describe the distribution and behavior of selective circuits and methods for their implementation. There are formulas provided for the calculation of the frequency components of selected second-order RLC filters. It further describes the choice of filter frequency components and computing relationships needed for the construction of coils. The work also includes a description and complete information needed for making measurements of the measurement of the RLC band-pass. The annex to this work includes all the materials needed for implementation of laboratory tasks designed to measure using the product.
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Magnetic Loop Antenna with Electronic Tuning for Frequencies below 30MHz
Svoboda, Luděk ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
The aim of this bachelor's project was realization of a tuning system with complete software and testing of the system's functionality and parameters of antenna. The system is divided into two parts, tuner and controller. The tuner implements change of circuit capacity by switching capacitor series. For switching is used transistor with small transitional capacity but small maximal collector current, too. This parameter restricts the use of system. The second part, controller, uses microcontroller AT89C2051. The microcontroller switches capacitors (and thus sets frequency) according to requests sent from PC with control software. The functionality was checked by tests with network analyzer.
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Defected ground planar filters
Tomíček, Martin ; Vágner, Petr (referee) ; Raida, Zbyněk (advisor)
In the bachelor´s thesis, the microstrip low-pass filter with the defected ground is described. The project deals with the design and the simulation of the filter in Ansoft Designer, confrontation of results between simulation and realized low-pass filter and the discussion of obtained results.
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Thermoregulator of piezoelectric crystal unit
Roubal, Zdeněk ; Vágner, Petr (referee) ; Kasal, Miroslav (advisor)
This thesis deals with thermal stabilization of crystal oscillators. A simple thermostat of piezoelectric crystal unit is designed in first part. Main emphasis is set to low input power. The second part deals with crystal oscillators with 102,5MHz and 10MHz frequency. They are simulated with Ansoft Designer software. Both of these oscilators are measured for short term and midterm frequency stability.
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Diagnostic of viral hepatitis B in the laboratory of serologic and molecular biology
Vagner, Petr ; Voxová, Barbora (advisor) ; Žáčková, Marta (referee)
Author: Petr Vagner Title: Diagnosis of viral hepatitis B in the serologic and molecular biology laboratory Field of study: Medical laboratory technician, combined type of study The aim of the study: The insight to the diagnosis of viral hepatitis B, with a focus on the examination of antibodies and antigens of Hepatitis B virus. Material and Methods: From 1st January 2011 to 31st December 2013 the serological laboratory of the Institute of Medical Biochemistry and Laboratory Medicine (ÚLBLD) in General University Hospital in Prague (VFN) 77,900 examinations were carried out by chemiluminescent immunoassay system ARCHITECT and system enzyme immunoassay AxSYM, which is used for detection of antibodies and antigens of the virus hepatitis B or detection of molecular biological methods for the detection of hepatitis B virus DNA, the determination of its genotype, drug resistance and pre-core mutations. Results: In total 92.90% of mentioned examinations were serological examinations and 7.10% molecular biological examinations. The examinations of serological markers of HBV were with the highest frequency of HBsAg testing (24, 033 tests) and 16 588 anti-HBs tests, the majority of requests was sent by The Center of Preventive Care (VFN), on the whole 4665 examinations of anti-HBs, from which 3,254 were...
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Thermodynamic analysis of solid oxide cells
Vágner, Petr ; Maršík, František (advisor) ; Grmela, Miroslav (referee) ; Pekař, Miloslav (referee)
Thermodynamic analysis of solid oxide cells Petr Vágner The thesis deals with continuum thermodynamic modeling and analysis of phe- nomena in solid oxide electrochemical cells. A general description of the evo- lution of charged mixtures using partial mass densities, momentum density, entropy density, electric induction, magnetic field, polarization, and magnetiza- tion based on the GENERIC framework is formulated. The formulation is used to recover the Landau-Lifshitz magnetization relaxation model, the Single Re- laxation Time model for dielectrics, and the generalized Poisson-Nernst-Planck model. The latter model is consequently linked to the second part, where a novel double layer model of an yttria-stabilized zirconia interface is formulated within non-equilibrium thermodynamics. The model is solved for numerically in the time domain, and cyclic voltammetry of the system is analyzed. The last part of the thesis demonstrates the limits of Exergy Analysis on a simple solid oxide hydrogen fuel cell model with non-isothermal boundary. It is demon- strated that the minimization of entropy production does not necessarily lead to the maximization of the electric power for certain optimization scenarios. The thesis consists of a compilation of published and unpublished results of the author.
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Magnetic loop antenna with electronic tuning for frequencies below 30MHz
Burda, Miroslav ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
This project deals with electronic tuning and automated adjustment of magnetic loop antennas, working in the High Frequencys. The whole work is divided into three parts tuning, adjustment and control). The tuning part is realized by changing the capacity of the array capacitors and adjustment is done by different changes of power points. The whole system is controlled by a microprocessor ATmega16. According to utility switches the microprocessor capacity, which tunes the antenna to the required frequency, processes information about power adjustment and autimatically fine-tuning the antenna by changing the position of charging.
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Physical analysis of the main processes in the solid oxide fuel cells and their mathematical description
Vágner, Petr ; Maršík, František (advisor) ; Souček, Ondřej (referee)
Solid oxide fuel cells (SOFC) are mainly used as large stationary elec- tricity sources, therefore an every little improvement in their performance leads to considerable savings. In order to understand the fundamentals of the SOFC operation, we have developed a new model describing the main physical processes. The thermodynamical model of SOFC, developed in this thesis, concerns the gas transport, the transport of the charged particles in- cluding the thermoelectric effect and the electrochemical reactions. Linear irreversible thermodynamics is the key modelling framework, in which the dusty gas model and the Butler-Volmer equations are used. A new relation between the electrochemical affinity and the overpotential is introduced into the Butler-Volmer equation. A weakly formulated statinonary system en- dowed with boundary conditions is solved with the finite element method in one dimensional approximation. 1
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Diagnostic of viral hepatitis B in the laboratory of serologic and molecular biology
Vagner, Petr ; Voxová, Barbora (advisor) ; Žáčková, Marta (referee)
Author: Petr Vagner Title: Diagnosis of viral hepatitis B in the serologic and molecular biology laboratory Field of study: Medical laboratory technician, combined type of study The aim of the study: The insight to the diagnosis of viral hepatitis B, with a focus on the examination of antibodies and antigens of Hepatitis B virus. Material and Methods: From 1st January 2011 to 31st December 2013 the serological laboratory of the Institute of Medical Biochemistry and Laboratory Medicine (ÚLBLD) in General University Hospital in Prague (VFN) 77,900 examinations were carried out by chemiluminescent immunoassay system ARCHITECT and system enzyme immunoassay AxSYM, which is used for detection of antibodies and antigens of the virus hepatitis B or detection of molecular biological methods for the detection of hepatitis B virus DNA, the determination of its genotype, drug resistance and pre-core mutations. Results: In total 92.90% of mentioned examinations were serological examinations and 7.10% molecular biological examinations. The examinations of serological markers of HBV were with the highest frequency of HBsAg testing (24, 033 tests) and 16 588 anti-HBs tests, the majority of requests was sent by The Center of Preventive Care (VFN), on the whole 4665 examinations of anti-HBs, from which 3,254 were...
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