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New Trends in Ionizing Radiation Shielding Research and Development
Vláčil, Martin ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This thesis deals with the problem of shielding ionizing radiation which is a beam that has enough energy to ionize an atom or a molecule of an irradiated substance. This radiation can occur in nuclear facilities such as a nuclear power plant, a particle accelerator, or in X-rays in healthcare. Until now, standard shielding materials, most often lead or concrete, have been used to protect against ionizing radiation. New trends are therefore trying to replace these materials with lighter, more effective and harmless materials. The practical part is focused on measure the data to obtain the basic properties of shielding materials, such as the attenuation factor and the buildup factor. A measuring platform is described here, which can be used to measure the data needed to calculate the attenuation factor and the buildup factor. The measurement results are compared with tabular values to determine the accuracy of the measurements. Furthermore, the results of measurements of five concrete materials from the company MICo, spol. s r.o. To obtain theoretical values, the simulation program MCNP6 was used, in which it is possible to create a model of the measuring platform, which was used in practical measurements. Next the shielding material, source and detector are defined. The result lead again to the data needed to determine the attenuation factor. The results of measurement and simulation data in MCNP6 are evaluated and graphically processed into such a form that it is possible to compare the properties of shielding materials with each other.
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Heat exchanger for rescue habitat
Bouma, Adam ; Kilkovský, Bohuslav (referee) ; Jegla, Zdeněk (advisor)
This thesis deals with the specific issues of designing a suitable type of heat exchanger for ventilation in a rescue habitat. The paper presents an overview of the most common types of heat exchangers and characterizes basic heat transfer mechanisms (radiation, convection). Based on the above and other knowledge, a thermal-hydraulic calculation model suitable for a regenerative heat exchanger type is compiled and the necessary calculations are performed. The thesis also contains an evaluation of the results for three materials which can be used in the production of a heat exchanger (aluminum, copper, steel).
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Conceptual design of a heat switch installation into a structure of satellite
Vrba, Martin ; Horák, Marek (referee) ; Mašek, Jakub (advisor)
Tato diplomová práce je zaměřena na sestavení přehledu konstrukcí a teplených cest kosmických lodí a kosmických vozidel, které se v současné době používají. Na základě specifických požadavků a standardů jsou vypracovány koncepční návrhy zástavby tepelného spínače do konstrukce družice. V jednotlivých kapitolách jsou popsány určité členy, které se na vedení tepla podílí a jsou důležité pro navrhované koncepty z pohledu konstrukce. Diplomová práce popisuje postupy výpočtu tepelných vodivostí a rozložení působící tíhové síly do míst uchycení pro jednotlivé koncepty. Na závěr provádí hodnocení a výběr potenciálně nejvhodnějšího návrhu.
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Cell - Phone Effects on Human Health
Pieniažek, Ireneusz ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This bachelor’s thesis is dealing with the influence of cell phones on man. First part is focused on the introduction to the problems of cell phone communication. There are described the frequencies and wave lengths, which the cell phones use. Here is also described the principle of cell phones functioning. Second part is devoted to influence of the cell phones on the human body. It is discussing the electromagnetic compatibility of the biological systems and describing the electromagnetic field occurring in cell phone communications. There are also described the thermal effects of the cell phones and this chapter further discusses the hypothesis about the non-thermal effects of the cell phones. There is a description of mechanism of influence of radio waves. This part also describes the possible health hazards resulting from the use of cell phones and the problem of relationship between the occurrence of cancer and the use of cell phones. There are mentioned other ecological problems connected with cell telephony. Third part is focused on the SAR measurement (specific absorption rate) of the cell phone. Here we can find the definition of SAR. It describes the tested apparatuses, the procedure of measurement and measured values for GSM 900, GSM 1800 and W-CDMA 2000 standards. Tested apparatus in this case is Samsung SGH-Z140V. We can find here technical engineering solutions, which are aimed to minimize the specific absorbing power absorbed by human body during the use of apparatus.
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Computational Modeling of Turbulent Swirling Diffusion Flames
Vondál, Jiří ; Klemeš,, Jiří (referee) ; Tuček,, Antonín (referee) ; Hájek, Jiří (advisor)
Schopnost predikovat tepelné toky do stěn v oblasti spalování, konstrukce pecí a procesního průmyslu je velmi důležitá pro návrh těchto zařízení. Je to často klíčový požadavek pro pevnostní výpočty. Cílem této práce je proto získat kvalitní naměřená data na experimentálním zařízení a využít je pro validaci standardně využívaných modelů počítačového modelování turbulentního vířivého difúzního spalování zemního plynu. Experimentální měření bylo provedeno na vodou chlazené spalovací komoře průmyslových parametrů. Byly provedeny měření se pro dva výkony hořáku – 745 kW a 1120 kW. Z měření byla vyhodnocena data a odvozeno nastavení okrajových podmínek pro počítačovou simulaci. Některé okrajové podmínky bylo nutné získat prostřednictvím dalšího měření, nebo separátní počítačové simulace tak jako například pro emisivitu, a nebo teplotu stěny. Práce zahrnuje několik vlastnoručně vytvořených počítačových programů pro zpracování dat. Velmi dobrých výsledků bylo dosaženo při predikci tepelných toků pro nižší výkon hořáku, kde odchylky od naměřených hodnot nepřesáhly 0.2 % pro celkové odvedené teplo a 16 % pro lokální tepelný tok stěnou komory. Vyšší tepelný výkon však přinesl snížení přesnosti těchto predikcí z důvodů chybně určené turbulence. Proto se v závěru práce zaměřuje na predikce vířivého proudění za vířičem a identifikuje několik problematických míst v použitých modelech využívaných i v komerčních aplikacích.
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OPTIMIZATION OF WELLNESS AIR CONDITION
Kysilka, Michal ; Zubíček, Vojtěch (referee) ; Šikula, Ondřej (advisor)
The theme of diploma thesis is a design optimization of air distribution in swimming-pool hall with regard to free water surface evaporation. This problem was solved according to determined criterions with the aid of CFD simulation. Experimental measurement part of the thesis deals with evaporation problems where own formula for this physical phenomenon is determined. This formula is compared with already known algorithms. Author suggests that such formula might be integrated in CFD software.
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Systems design and possibilities of utilization of photovoltaic power station in the Czech Republic
Švec, Radovan ; Procházka, Zdeněk (referee) ; Mastný, Petr (advisor)
This bachelor thesis deals with project and possibilities of use of photovoltaic power stations at the area of the Czech Republic. The first part is dedicated to state and aproach to solar energy in our state and abroad. In the second part are described parts of mecanism used for conversion of solar radiation to electric energy. The third part deals with physical principal of photovoltaic effect. Other parts are dedicated to general project of photovoltaic power station and in the final part economic evaluation of project and joining to the transmission system are mentioned.
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Thermomechanical tire model
Vaníček, Jan ; Štětina, Josef (referee) ; Porteš, Petr (advisor)
This diploma thesis is about thermomechanics of passenger car tires. The research part dealing with existing tire models is followed by the practical part. The practical part is based on the designs of thermomechanical models. The first model determines a dependence of temperature on the air pressure inside a tire when a temperature changes. The second thermomechanical model captures all the heat fluxes which affect a tire while a vehicle is in motion. The third thermomechanical model calculates temperatures of parts of the tire during driving tests. All models are programmed in MATLAB.
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