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Determination of evapotranspiration from small catchments
Toušková, Jitka ; Šípek, Václav (advisor) ; Možný, Martin (referee) ; Brom, Jakub (referee)
Evapotranspiration (ET) plays a significant role in the hydrological balance. The terms potential (PET) and reference (RET) evapotranspiration are often used while estimating its rate. The doctoral thesis deals with the estimation of PET, RET and other selected processes. First, the influence of net longwave radiation (the component of radiation balance) on the rate of PET was examined. It was found that the standard methods result in the significant differences in PET estimation due to the absence of model calibration to local conditions. The original model caused distinction in the PET evaluation for the Liz experimental catchment by up to 100 mm/year. Calibration of the parameters of two commonly used methods for calculating net longwave radiation reduced the error in PET evaluation to less than 20 mm/year. PET or RET estimation itself can be performed by many direct or indirect methods. Their accuracy is highly discussed. This work focused on selection of suitable methods and their further testing on conditions of 18 stations in the Czech Republic. 37 methods were compared with measured data. It was proven, that the best results in this region were achieved by combination methods (with average RMSE of 1.2 mm/day, 18.6 mm/month, and 33.3 mm/year). Among individual models, the radiation-based...
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Non-contact Temperature Measurement
Lata, Miroslav ; Janečka, Jan (referee) ; Vdoleček, František (advisor)
The object of this bachelor thesis was to create a study of development non-contact temperature measurement and show methods of measurement in infra-red radiation area. The beginning of this work is focused on major notions and definitions necessary to introduce non-contact temperature measurement topic. Other interest of this work was to mention possible error rate of measurement, it’s reasons then name some ways of calibration of a measuring equipment with it’s reasons too. Last part of this thesis was focused on a practical using of these measuring devices.
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Nuclear accidents
Mik, Martin ; Suk, Ladislav (referee) ; Vojáčková, Jitka (advisor)
This thesis is a research dealing with nuclear accidents and disasters in the world and us. The work is divided into several parts. The first part deals with the regulation of nuclear safety in the Czech Republic. The second part describes the international INES scale. The last and largest section deals with the actual accidents and disasters.
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Algorithm for Calculation of Radiation View Factors
Bílek, Tomáš ; Hlavička, Rudolf (referee) ; Čermák, Libor (advisor)
This thesis deals with a calculation of radiation view factors. The thesis includes mathematical model of the problem and its numerical solution. The main aim of the thesis is the creation of an algorithm for calculation of radiation view factors for given 3D geometries and its application for the heat flux analysis. CAD models of geometries, specified by a NASTRAN file format, are used as an input of the algorithm. Matrix of radiation view factors serves then as an output of the algorithm. The algorithm is programmed in MATLAB, but STAR-CCM+ is used for the NASTRAN specification of separate models. The algorithm is also designed for a computation on a computer cluster for cases of intricate geometries with consideration of shading areas.
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Simplified modelling of tube bank heat exchanger in CFD
Cacková, Tereza ; Juřena, Tomáš (referee) ; Vondál, Jiří (advisor)
The master thesis deals with the replacement of heat exchanger surfaces during simulations in the ANSYS Fluent. The aim of this work is to find a simplified model of the heat exchanger usable for flow simulations in large process and energy units, where it is not possible to model the entire heat exchanger in detail. The calculation procedures are applied to „tube bank” heat exchanger. The master thesis is divided into three parts. First part deals with pressure losses. The "porous zone" approach is used as a replacement for the heat exchanger surface. In the second part, the heat transfer by convection and conduction through the heat exchanger is replaced by the "Heat Exchanger" module. The third part examines the influence of material properties, heat source and fixed temperatures on incident radiation. All calculations resulting from the methods are performed using a script that prepares the output data in format suitable for insertion into ANSYS Fluent. A simplification, which faithfully replaces a fully modeled heat exchanger, has been found in all three parts of the thesis.
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Control unit for CubeSat
Horký, Jan ; Šulc, Tomáš (referee) ; Kubíček, Michal (advisor)
Cílem práce je návrh univerzální řídicí jednotky pro CubeSat založené na obvodu FPGA. Taková jednotka doposud nebyla komerčně dostupná a navržená jednotka má tak dobrý potenciál zaplnit příslušné místo na trhu komponent pro CubeSat. Celá jednotka je navržena z komerčně dostupných komponent. Návrh jednotky je proveden tak, aby umožnil její funkci ve vesmírném prostředí. Stav konfigurace FPGA je pravidelně kontrolován a v případě zjištěné chyby dochází automaticky k rekonfiguraci FPGA a návratu jednotky do výchozího stavu. Jednotka obsahuje sadu senzorů, které monitorují její stav a v případě potřeby je možné na základě jejich výstupů provést opatření z hlediska ochrany funkce jednotky. Dvě paměti MRAM umožňují uložení tovární a uživatelské konfigurace FPGA, mezi kterými dochází k automatickému přepnutí na základě korektnosti uživatelské konfigurace.
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Gamma Radiation Measurement
Lázna, Tomáš ; Jílek, Tomáš (referee) ; Žalud, Luděk (advisor)
This thesis is focused on detection of ionizing radiation, especially gamma radiation. In its theoretical part the issue is presented and the most common detector types (gas filled, scintillation and semiconductor detectors) are analysed. In its practical part the parameters of the chosen sensor HDS-100GN are verified with a focus on its capability of dynamical measurement. The robot Orpheus-X3 equipped with the precise RTK-GNSS receiver was used in the realization of the experiment. The analysis of the measurement results furthermore covers conversion of geographical coordinates to distance, determination of latency, conversion of measured value to dose rate and comparison with theoretical assumptions were solved. Formation of an area radiation map is also concerned. Direction-sensitive detection of gamma radiation is also studied in this thesis.
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The effects of ionizing radiation on semiconductor devices properties
Yermalayeva, Darya ; Šteffan, Pavel (referee) ; Musil, Vladislav (advisor)
This master’s thesis deals with the problematics of influence of ionizing radiation on semiconductor devices and their properties. The aim of the thesis is to analyze the different types of radiation that can occur in the areas of application of these components. In the second part, the degradation processes are explored, with emphasis on the influence caused by the radiation dose. Also, the displacement damage and SEE effects are described, but just slightly, because they are not part of this work. The third part describes the device design process and harmful effects, that have to be considered during the design phase. In the forth and the fifth parts of this work were done modeling of radiation effects (influence of dose rate, Single-Event Upset and Total Ionizing Dose) in PSpice program and was carried out the possibility of designing a simple dosimeter with silicon diode. In conclusion, the results of the thesis are summarized and evaluated.
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Decontamination of Persons at Medical Facilites during CBR Events
Magulová, Eva ; Urbánek, Pavel (referee) ; Rosická, Zdena (advisor)
The aim of this work is the effort to bring new insight into the possibility of decontamination in healthcare facilities. In the first part are briefly explained keywords. The second part is a brief preview of the sarin attack in the Tokyo metro and the cooperation of Japanese rescue system in this event. It is followed by estimated procedure of integrated rescue system of the Czech Republic at the same event in the Czech Republic. Then is a proposal of some problems arising from improvised decontamination in the unequipped hospital and a proposal for the possible course of decontamination in a medical device.
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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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