 

Geometry of PoissonLie Tduality
Svoboda, Josef ; Jurčo, Branislav (advisor) ; Deser, Andreas (referee)
In this thesis we study geometry of PoissonLie Tduality. We develop the language of Lie and Courant algebroids and study generalized metrics on them. Then we use Dirac structures and generalized isometries to formulate a general version of PoissonLie Tduality, a nonabelian version of Tduality, known from string theory.

 

Fabrication and calibration of thermocouples
Balák, Martin ; Svoboda, Josef (referee) ; Foral, Štěpán (advisor)
This thesis is focused on the creation of laboratory task. The first part describes the operating principle of the thermocouple and according to which the physical laws are working. The thesis also shows the main categories of the division of thermocouple. Next chapter explains the composition of thermocouple welder, its main components and how the process of welding thermocouple wire is under way. The last chapter of the theoretical part is focused on the calibration of thermocouples. This chapter explains what the calibration is and it also shows the examples of calibration on real devices. The first part of the practical section describes the construction of the laboratory product and what materials were used for the given construction. The following part deals with the electrical interior of the thermocouple welder. Electrical diagram is described and there is also the description of how to direct and regulate the supply voltage and how it reaches the clamps of the capacitor. Its charging is observed by measuring instrument (voltmeter). The thesis works with the proper welding procedure, its potential problems, and the correct method of welding because the weld must be in sufficient quality in order to pass the calibration. This work also shows how the welds should not look and what to do in case they do not look well. The second part of the practical section deals with the comparison of welded thermocouples tested on produced product and on SR80 UWO. The three pieces of thermocouples were welded on each of them. Their following comparison is the proof of the quality of the welding preparation. The last part of the second practical part is focused on the calibration of the thermocouple prepared thanks to the product.


Universal quadratic forms over number fields
Svoboda, Josef ; Kala, Vítězslav (advisor) ; Hejda, Tomáš (referee)
The aim of this work is to study universal quadratic forms over biquadratic fields. In the thesis we define biquadratic fields and describe their structure. In particular, we study some distinguished (totally positive and aditively indecomposable) elements, their norms and traces. Then we describe the theory of universal quadratic forms and use special elements to find a lower bound for the number of variables of a universal quadratic form over some biquadratic fields.


The temperature field analysis of the subcritical acceleratordriven reactors
Majer, Šimon ; Šťastný, Ondřej (referee) ; Svoboda, Josef (advisor)
The aim of the bachelor thesis is to discuss the problems of accelerator driven system, to describe the possibilities of temperature measurement, to create model of the spallation target QUINTA target in the program Inventor and to perform the simulation by using the Ansys software. The theoretical part is focused on nuclear energy and its potential for the future and continues smoothly to the issue of accelerator driven system (ADS), where it discusses the possibilities of using mentioned system. The thesis is processed from the point of view of electrical energy, focusing on generation issues and the possibility of heat monitoring. The possibilities of temperature measurement are discussed here for calculation and simulation of heat transfer. The practical part of the bachelor’s thesis is processed with the help of the Joint Institute for Nuclear Research in Dubna, where the ADS research is in process. The input data and the size of the geometry were provided by the JINR research team and were used to simulate heat transfer by using the Ansys program. The results of the simulation are processed graphically in the last chapter of the bachelor thesis.


Numerical simulation of crack propagation in ceramic composites in 3D
Svoboda, Josef ; Horníková, Jana (referee) ; Majer, Zdeněk (advisor)
The strength of materials such as glass and ceramics can be influenced by the environment (stress corrosion). Under applied stress defects (cracks) can grow subcritically below fracture toughness K_Ic. The aim of this work was to develop a threedimensional finiteelement model to analyze the subcritical crack growth behavior of ceramicbased particulate composites. The maximum tangential stress criterion (MTS) was used to predict the direction of the crack propagation in the framework of linear elastic fracture mechanics. The modeled material was a Low Temperature Cofired Ceramics (LTCC), containing alumina particles embedded in a glass matrix. The main aim of this work was to develop a 3D model describing the crack growth. Conclusions from this work can contribute to a better understanding of subcritical crack propagation in particle composites.

 

Heat transfer by thermal radiation
Budovec, Michal ; Svoboda, Josef (referee) ; Foral, Štěpán (advisor)
This bachelor’s thesis deals with heat transfer, specifically with thermal radiation heat transfer by convection. The work is divided into theoretical part and calculations. The theoretical part describes basic thermomechanical notions and all kinds of heat transfer with the emphasis on heat transfer by radiation with convection. Heat conduction chapter describes the basic types of heat conduction. In chapter Heat transfer by convection are given criterion equations and examples for determining dimensionless numbers. Radiation heat transfer chapter focuses on heat transfer between two bodies and the radiation factor. With this equations and dimensionless numbers are quantifying variables in the calculation part. In the theoretical part is wrought calculation for a given case of heat transfer in the air and vacuum. The calculation is experimentally verified, from which is wrought protocol with the measurement and comparison with calculation and measurement in the air and vacuum.

 