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Determination of optimum sintering schedule of oxide ceramics
Průdek, Miloš ; Hadraba, Hynek (referee) ; Maca, Karel (advisor)
The sintering of cubic ZrO2 (stabilized with 8mol% Y2O3) by Single-Step sintering was studied in this bacherol‘s thesis. Two types of commercial powders with different particle size of 80nm and 140nm were used. It was studied whether the grain size of the sample sintered for shorter time at higher density is higher or smaller than after sintering for longer time at lower temperature. It was found taht for cubic zirconia the sintering for a longer time at lower temperature is advantageous from the point of view of decreasing the grain size fo cintered ceramics.
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A fuel cell, as an alternative source of electricity
Kürthy, Marián ; Šen, Hugo (referee) ; Pospíšil, Jiří (advisor)
The work deals with fuel cell technology, the principle of fuel cells and their division. Also there is presented an option of natural gas utilization as a fuel for fuel cells in this work. In the end of this work two scenarios of fuel cell usage in microcogeneration are introduced and there is also a technical economic evaluation of fuel cell microcogeneration unit used in these scenarios.
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The use of Computers in the Number Theory
Konečný, Zdeněk ; Karásek, Jiří (referee) ; Skula, Ladislav (advisor)
PARI/GP is a relatively obscure mathematical software that was designed especially for quick calculations in the number theory, but which has also found its application in other areas of mathematics. This work gives an overview of the basic commands of PARI/GP, and some simple examples to show their potential use. PARI/GP is then used for looking for large primes of special forms.
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Physics of Metamaterials
Láska, Martin ; Kalousek, Radek (referee) ; Dub, Petr (advisor)
The bachelor work deals with electrodynamics of metamaterials for which both the electric permittivity and magnetic permeability are simultaneously negative. It is shown that the double negative media are described by a negative refraction index which has an important impact on optics laws. In particular, the negative refraction is demonstrated by simulation of interaction of the Gauss monochromatic beam impinging on a negative refractive material. Next, the electromagnetic energy propagation in the negative refractive materials is studied. It is shown that the energy propagation velocity equals the group velocity, which has the opposite sign than the phase velocity. Finally, Fresnel formulas valid both for positive and negative refraction index are given.
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Accumulation of energy
Neuman, Tomáš ; Kloss, Ondřej (referee) ; Kaplan, Zdeněk (advisor)
This bachelor thesis comprises a technical retrieval of overview of energy accumulation usable in cars. The basic characteristics and problems of particular kinds of accumulators and ways of accumulation are brought in this thesis, describing characteristics of lead accumulator, the structure and composition of electromobiles and appropriate batteries. In the following part the description of heat and hydrogen accumulator is stated. The end of this bachelor thesis is dedicated to mechanical accumulator.
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