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Numerical Modeling of Periodical Structures
Nešpor, Dušan ; Bartušek, Karel (referee) ; Brančík, Lubomír (referee) ; Fiala, Pavel (advisor)
The thesis discusses the dynamic electromagnetic field on periodic structures. The author focuses on three principal types of resonant structures, considering their application possibilities. In general, these types can be individually defined as follows: materials exhibiting a negative refractive index of the incident electromagnetic wave; structures with gradual changes in impedance, characterised by their usability as reflectionless surfaces; and periodic structures able to conveniently shape the magnetic field distribution. Materials of the third group within the above-shown short list facilitate the fabrication of magnetoinductive lenses for nuclear magnetic resonance. The presented analysis of the properties of periodic resonant structures is mainly based on numerical models utilising the finite element method, and this approach is combined with both the derivation of the corresponding analytical relations and an experimental measurement of the non-radiating component of the electromagnetic field. The thesis includes a physical description of the basic elements of periodic resonant structures. Physical properties of the elements were examined in detail via numerical analysis. In the course of the research, the data acquired through this analysis and the related experimental measurement enabled the author to propose a method for optimising the most widely used resonant structures. Moreover, several new versions of resonant elements, structures, and fabrication techniques were also designed. The results obtained from the numerical analyses carried out to examine the central physical properties of the fabricated structure samples were all verified via the designed method for measuring the non-radiating component of the magnetic field.
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Stone columns - importance of arch effect
Vanko, Peter ; Zdražil, Karel (referee) ; Miča, Lumír (advisor)
The aim of the the thesis is to study the development of arch effect depending on the change of the various parameters such as grid of columns, height of embankments, material of embankment fill and material of columns. The first phase of work summarizes theoretical knowledges of stone columns and arch effect. The next phase deals with analysis of the effect of arch using numerical modeling. In the next part of the second phase circular tank based on stone columns will be modeled, where deformations and stress on columns will be monitored in changing constitutive model and applying substitute characteristics. Obtained results will be evaluated in conclusion.
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Static load test and the assessment ceiling of reinforced concrete structure built in the 1st half of 20th century
Málek, Jaroslav ; Láník, Jaromír (referee) ; Žítt, Petr (advisor)
This master thesis deals with static load test and static assessment of selected segments of reinforced concrete ceiling construction of the Hennebique system at the Faculty of Arts at Masaryk University in Brno. This thesis contains: the execution of the static load test, the data evaluation of the static load test and the data evaluation of the complementary laboratory testing, geometric orientation of bearing elements, the checking of the ceiling placement in the peripheral position, and the diagnosis of the reinforcing of the construction. This thesis also includes the static assessment according to various standard norm rules and the numerical analysis in ATENA software program.
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Equivalent circuit realizations of the simple chaotic oscillators
Kobza, Jaromír ; Dostál, Tomáš (referee) ; Petržela, Jiří (advisor)
The aim of this paper is to introduce with basic theory the problems encountered when considering the circuit implementation of autonomous RC chaotic oscillator with nonlinearity. All oscillator prototypes are based on one type of universal oscillator circuit. This circuit is able to generate a lot of attractors on condition of different entrance parameters. The design is based on a mathematical simulation, which includes the generation of electronic circuit values. The work is focused the transformation of these values to operational circuit configuration and simulation in a circuit simulator. The final task is to acquire chaotic attractors. Oscilloscope and spectrum analyser photos will verify the operation.
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Driven chaotic oscillators
Pšeno, Daniel ; Guzan,, Milan (referee) ; Petržela, Jiří (advisor)
The theme of this masters thesis are driven chaotic oscillators. The aim of this project is show the various types of driven chaotic oscillator and propose mathematical model solutions using numerical methods. In the first part of this thesis are shown theory of chaos, history of chaos theory, chaotic systems and chaos quantifiers. Next is numerical analysis of differential equations second order by Runge-Kutta fourth order method. Next part contains circuit blocks and synthesis of oscillators. In next part are defined all types of oscillators. Parameters of analysis, equations, circuits and simulations are defined for each type of driven chaotic oscillators. In each subchapter is design electrical circuit. This circuit is simulated and some of them realized.
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Thermal conductive plate with controlled thermal field
Masár, Pavol ; Král, Bohumil (referee) ; Steinbauer, Miloslav (advisor)
This work deals with design of thermal source of panel shape for scientific biological application. Panel has adjustable surface temperature and thermal gradient. The first part of this work concern with design and numerical modeling of the thermal system, application of materials and arrangement of thermal and cooling devices – Peltier elements. Second part of this work is about construction of the panel and experimental measurement.
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SMV-2014-17: Metrology and Optimization of Parameters in Electronic Systems
Bartušek, Karel
The presented contract research comprised development and experimental investigation aimed at devising methods for the metrology and optimization of parameters in electronic systems designed at the Faculty of Electrical Engineering and Communication, Brno University of Technology (BUT). Within the first partial task, we proposed a metrology technique to measure the concentration of air ions within the range of between 50 and 100,000 ions/cm2; furthermore, a Gerdien tube prototype was fabricated, and the electronics of a ionmeter developed by BUT were calibrated in various environments. The result of the second partial task consisted in the actual design and fabrication of a high-frequency coil system exhibiting a maximum homogeneity; this system was then experimentally verified on a 4.7 T MR tomograph and compared with probes equipped with saddle and slotted-tube coils. Probe tuning mechanisms were also included in the design.
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Hard-coupled model of local direct resistance heating of thin sheets
Karban, P. ; Mach, F. ; Doležel, Ivo
A monolithic model of local direct resistance heating of thin sheets is presented. The model respects all nonlinearities of the system such as the temperature dependencies of physical properties of individual parts of the system. Numerical computations are performed by a finite element method of higher order of accuracy and realized by our own codes Hermes2D and Agros2D. The methodology is illustrated by a typical example whose results are discussed.
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SNA ´09 - Seminář numerické analýzy
Blaheta, Radim ; Starý, Jiří
Seminar on Numerical Analysis 2009 (SNA’09) is the sixth meeting of a series of events started in Ostrava 2003 and devoted to numerical methods necessary for mathematical modelling of problems in sciences and engineering. In this respect, it was natural that in period 2005 - 2008 the SNA conferences became a part of the project MSTEP (http://www2.cs.cas.cz/mweb/) Modelling and simulation of complex engineering problems: effective numerical algorithms and parallel implementation using new information technologies within the program Information society administrated by the Academy of Sciences of the Czech Republic. We hope that the tradition of SNA conferences will be preserved even after finishing the MSTEP project in 2008.
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