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Meteorology and measurement techniques
Vaňousová, Jana ; Hammer, Jaromír (referee) ; Jebáček, Ivo (advisor)
This thesis deals with the branch of science called Meteorology. It is connected with measurement techniques, too. Basic terms are defined, structure and classification of atmosphere there are briefly described and furthermore basic meteorologic components are analysed. Finally there is an evaluation of meteorologic data measured unprofessional meteorologic station.
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Quantification of natural water retention capacity in selected watersheds
Pavlík, František ; Švihla,, Vladimír (referee) ; Pavelková,, Renata (referee) ; Dumbrovský, Miroslav (advisor)
The aim of this work is to quantify the natural water retention capacity of the landscape in selected catchments and determine the significance of selected climatic and geographic basin factors on components of retention capacity. 18 rainfall-runoff events were selected in 11 catchments for quantification of the natural water retention capacity of landscape. Land cover, geomorphological, pedological and hydrological conditions were analyzed for this basin using GIS tools. Historical rainfall-runoff events for which were restored historical land cover were also evaluated in this work. Two different methods were used for the quantification of retention capacity, one of them was used in two variants. A rainfall-runoff models and simulated scenarios of land cover (positive and negative) were constructed in two selected catchments in HEC-HMS. The work also use previously performed simulation scenarios of land cover formulated by other authors. Total final set of 33 rainfall-runoff events were subjected to statistical correlation and regression analysis. The goal of these analyses was to determine the significance of individual parameters assessed in relation to the components of natural water retention of catchment.
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Aircraft windshield blowing: solution and design possibilities
Šamša, Petr ; Fišer, Jan (referee) ; Jícha, Miroslav (advisor)
My thesis is considering with aircraft windshield blowing for airplanes designed according to CS-23 regulation. The first part introduces the size of precipitation clearing area in connection with CS-23 regulation and report SAE AIR805C. Next chapter describes a few possible design solutions which can be potentially used for windshield precipitation. There are also other methods analysed in that part. There are not only the casual systems like windshield wipers but some more rare or new technologies too. It can be some fluid repellent surfaces or blowers in that category. The third part deals with jet blast system in detail. There will be a design calculation for airflow conditions which are important for the correct function. The last quarter of this thesis mentions the experiment what should compare the theoretical computations from the third part with the real values.
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Wireless weather station
Filka, Tomáš ; Novotný, Radovan (referee) ; Levek, Vladimír (advisor)
This diploma thesis deals with a draft of wireless weather station, whose task is to measure basic values inside and outside the home. Measured variables are for example temperature, atmospheric pressure, relative humidity, wind speed and direction or concentration of carbon dioxide (CO2). These data will be transmitted to a web server for later processing. Possible technical solutions are described and the outcome is a designed printed circuit boards, which has been assembled and tested. Resulting system was tested in trial operation.
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High entropy alloys fabricated via SPS compaction of high energy milled feedstock powders
Gubán, Ivan ; Hadraba, Hynek (referee) ; Čížek, Jan (advisor)
The subject of this thesis is preparation of CoCrFeMnNiNx high entropy mixtures via the methods of mechanical alloying and spark plasma sintering (SPS). Three series of specimens were fabricated in this thesis: samples milled in argon (benchmark materials), samples milled in nitrogen atmosphere (to observe their ability of nitrogen absorption) and samples microalloyed with CrN, FeN nitrides (to observe their dissociation into the solid solution potential). The fabricated powders and SPS compacts were subsequently observed by electron microscopy and their phase content by X-Ray diffraction (XRD) and elemental composition by EDS analysis were carried out. A method of reduction melting in inert atmosphere was used to determine the exact oxygen and nitrogen content in powders, while the respective particle size distribution measured by laser diffraction method. The influence of nitrogen content on the hardness of the samples was studied via the microhardness measured. After completing the process of mechanical alloying under the Nitrogen atmosphere was the maximal concentration of nitrogen in the structure 0,208% after 24 hours of milling (dependency on time was linear), which means, the method of milling under the Nitrogen atmosphere was successful. XRD of milled samples showed the existence of the only FCC single solid solution phase, while samples milled under the Nitrogen atmosphere showed the trend of the growth of the lattice parameter with the increasing nitrogen content. There was observed the presence of the chromium nitrides precipitates on the grain boundaries of the FCC phase in microalloyed samples. All specimen were contaminated by a mixture of metallic oxides and manganeese sulphides, which were present in the default manganeese powder. The greatest value of microhardness showed the duplex sample. The increase in values of microhardness (344 HV 0,3) in comparison with the standard sample (262,9 HV 0,3) was recorded on the samples milled under the nitrogen atmosphere, which conforms the positive influence of the nitrogen content on strength characteristics of this alloy.
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Advanced ceramics for tissue engineering
Vojtíšek, Jan ; Koplík, Jan (referee) ; Bartoníčková, Eva (advisor)
This bachelor´s thesis deals issues of ceramics materials suitable for tissue engineering. An artificial substitute for human tissue can be divided to several generations. This include inert, bioactive and bioresobable materials. Resorbable substitutions are prepared from materials, which could substitute host tissue, for example hydroxyapatite. HA can be prepared in different ways (dry and wet way). To better application in medicine, ceramics foams prepared by in situ foaming or replication technique are using. Experimental part of this paper deals preparing of hydroxyapatite powder and process optimization. Samples was characterized by IR and Raman spectrometry, XRD analysis and particle size was studied by SEM. Ceramics foams was prepared by in situ foaming from Al2O3, HA and composites (in ratio 50 – 50, 75 – 25, 90 – 10). Porosity was evaluated by stereomicroscope, density and level of sintering was studied by SEM microscopy.
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Realistic Model of the Sky
Kussior, Zdeněk ; Bílek, Václav (referee) ; Drahanský, Martin (advisor)
The paper describes a theoretical base and realization of realistic volumetric clouds visualization in an environment of real-time simulator. The first part is concerned with a meteorological background of this problem. I show international classification of ten basic cloud types including a short description and cases of occurence. The following part is concerned with an interaction between cloudiness and simulation core, which is based on the fact, that each cloud acts as a mechanical or an electromagnetic obstacle. This should be considered on some way in simulation. The next part describes technologies and practical implementations of visualization and evaluates their characteristics. Finally, the last chapter describes my implementation and tries to outline project advancement.
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Study of intermetallic phases in cast duplex steel
Ponížil, Ondřej ; Foret, Rudolf (referee) ; Pacal, Bohumil (advisor)
This thesis deals with the study of intermetallic phases in cast duplex stainless steel ASTM A890 Grade 4A considering degradation of mechanical properties in the result of isothermal aging in the temperature of 700 °C and 595 °C. The period of aging in the temperature of 700 °C was ranging from 1 to 160 hours and in the temperature of 595 °C it was ranging from 24 to 245 hours. The study of microstructure after aging in the temperature of 700 °C has proved that the -phases, Laves phases, chromium carbides and chromium nitrides were excluded. The phase was observed after four hours of aging in the temperature of 700 °C in / interface for the first time. The transformation was performed by eutectoid mechanism according to the equation + 2. The Laves phase has been observed after 10 hours of aging in / interphase and later in the ferrite grain as well. Chromium carbides and nitrides have created a continuous contour along to the / and /2 interface. After the temperature of 595°C there have been observed a large amount of small precipitates in the structure. The precipitates have been extracted from some selected samples to carbon replica. Following analysis has confirmed the presence of chromium carbides, -phases and Laves phases. The deterioration of mechanical properties, caused by the influence of secondary phase exclusion, has been confirmed by the Vickers hardness test and impact test including fractography analysis of the fracture surface. The hardness has an increasing tendency while the impact strength has been significantly reduced.
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Precipitation Forecast from Weather Radar
Tábi, Matej ; Milička, Martin (referee) ; Burget, Radek (advisor)
The aim of this bachelor thesis is a web application, which solves a short-time precipitation forecast for Czech Republic. The forecast is created for the next one hour and consists of four radar frames with a 15 minutes distance between them. The task is solved in three main steps. In the first step, the actual information from CHMI webpages is obtained. In the second step, the recieved data is processed - precipitation fields are identified and in the last step, movement vectors of these precipitation fields are calculated. The result of the thesis is a fully working web application. The forecast success rate is at the level from 30 to 60%.
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