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The technology of aerated concrete
Koutný, Ondřej ; Repka, Martin (referee) ; Opravil, Tomáš (advisor)
Civil engineering is integral part of industry in each developed country. Naturally the construction point does not play the main role here, but also the material of building segments. In last fifty years the new possibility has been discovered against classic brick in form of autoclaved aerated concrete. This material gathers its customers not only due to low weight and easy application with sufficient strength, but particularly due to excellent heat-insulation properties. Contemporary trend in research of aerated concrete points to application of alternative raws, as for example metakaoline, to improve final properties of product by preserving of current technology and price.
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Investment casting waxes and measurements of their properties with regard to simulation software
Bochníček, Štěpán ; Mikulka, Vít (referee) ; Kosour, Vojtěch (advisor)
Today, the use of simulations is increasing in order to reduce cost and complexity of production and also to prevent product defects. For this purpose, we use simulation programs, such as ProCAST. This program is designed for simulation of casting parts. In my bachelor thesis I focused on the methods of casting lost wax, where the model is made of wax mixture. In each simulation we have to obtain and specify the properties of the material to casting. I described these properties and methods of measurement in this bachelor thesis.
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Identification of Thermal Conductivity and Thermal Capacity of Building Materials by the "Hot Wire Method"
Průša, David ; Čermák,, Jan (referee) ; Šťastník, Stanislav (advisor)
This aim of task deals with study of heat dissipation mechanisms and the description of physical phenomena, which is accompanied by non-stationary measurement of thermal characteristics by the method "hot-wire method". In particular, we observe the coefficient of thermal conductivity and its dependence on various variables such as the temperature of the measured sample, its moisture state, the volume of the sample and its porosity. The above mentioned findings are used for the invention of the measuring device of a nonstationary gauge, which is based on regular heating and is dedicated to measuring the thermal conductivity coefficient and the heat capacity by the "hot-wire method" method. In the last part of the thesis is verified functionality of the proposed measuring device, the suitability of the created algorithm for the processing of the measured data and the evaluation of the results was verified. The reproducibility of the measurements was verified and the measured results were compared with the measurement methods, which are commonly used. the influence of humidity on the coefficient of thermal conductivity.
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Thermal conductivity measurements
Krejčí, Jakub ; Bejček, Ludvík (referee) ; Beneš, Petr (advisor)
This bachelor thesis deals with non-stationary thermal conductivity measurement using line and point heat source. There are compared various methods thermal conductivity measurement and designed own correction for pulse duration. The practical part describes created exemplar for laboratory exercises including achieved results and comparing with simulations.
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Experimental study on satellite´s passive thermal-regulation units
Mateášik, Timko Marek ; Mašek, Jakub (referee) ; Lazar, Václav (advisor)
Diplomová práca sa zaoberá vplyvom termálnych medzivrstiev na tepelnú kontaktnú vodi- vosť a tepelný kontaktný odpor. Práca sa zameriava na aplikáciu termálnych medzivrstiev pre vylepšenie tepelnej kontaktnej vodivosti v tepelnom spínači a v kozmických zariade- niach obecne. Teoretická časť práce stručne skúma rôzne pasívne termálne kontrolné systémy použí- vane v kozmických zariadeniach, vrátane termálnych medzivrstiev, a vysvetľuje pozadie tejto práce. Táto práca ďalej skúma rôzne termálne medzivrstvy, predovšetkým povlaky a fólie, a uvádza výber vhodnej termálnej medzivrstvy. Experimentálna časť práce skúma povrchové parametre, tepelnú vodivosť a mikrotvr-dosť medených vzoriek, ktoré slúžia ako substrát pre povlak čistého striebra. Ďalej rieši podmienky merania, metódy vyhodnocovania a samotné experimentálne merania. Experimentálne merania sú vykonané v termo-vákuovej testovacej komore a na základe výsledkov sú vyvodené závery. Pre ďalšiu prácu sú uvedené doporučenia.
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Pile Foundations - Energy Piles
Hoza, Martin ; Leiter, Augustin (referee) ; Glisníková, Věra (advisor)
At a time when ecology and renewable energy sources come to the fore, the use of geothermal energy appears to be one of the suitable alternatives. The aim of this paper is to explain the function of ground source heat pumps, to mention factors affecting the efficiency of the system and discuss the technology of energy piles realization. This paper also focuses at risks associated with the soil temperature influencing and shows examples of realization.
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Nuclear Fuel Innovation
Mičian, Peter ; Zeman, Miroslav (referee) ; Katovský, Karel (advisor)
This bachelor thesis deals with the latest findings about nuclear fuel, especially fuels for pressurized water reactors. The thesis provides an overview of the latest research in the field of fuel cladding, which separates the fuel from coolant. Part is focused on burnable absorbers, which helps to reduce neutron flux during the first year of new fuel assembly. Furthermore, the thesis briefly discusses transmutation fuel cycles. the main empahsis is focused on ATF fuels, in the form of fuels with enhanced thermal conductivity. Develompment in this field could increase the safety and usage of the nuclear energy. The latest part is focused on applications of computational program FEMAXI-6 and analyze its outputs. This program deals with calculations of behavior of high-burnup fuel elements. As data for inputs were used real data from the nuclear power plant Dukovany.
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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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Methods of Space and Spectral Characterization of Light Sources used in Car Industries
Guzej, Michal ; Černý,, Pavel (referee) ; Samek, František (referee) ; Horský, Jaroslav (advisor)
Automotive headlamps work in very variable operating conditions during which the producer have to guarantee their primary function of seeing and being seen. During the development stage of the new headlamps the manufacturers want to eliminate defects which could led to malfunction in operation. The numerical simulations along with the test procedures are appropriate tools for detection of problematic areas. The most appropriate approach is designing of experiment with a view to the subsequent simple implementation of the measured data into numerical simulations software and carefully choosing a measuring method of the monitored physical quantities. The thesis deals with phenomenon of condensation in headlamps, which has a negative effect on the light distribution and their life expectancy. Due to this experimental defog methodology was developed based on evaporation of a specified amount of water into the headlamp and then condensation on the inside surface of the headlamp lens. Pictures are taken during the measurements and the fogged and defogged areas are automatically detected. The results from experiments are used to adjust and verify a numerical model. The next part is devoted to the thermal load of the headlamp components which are mostly heated by waste heat from light sources. This phenomena depends mainly on the type of source, emissivity and thermal conductivity. A methodology of temperature measurement, thermal conductivity measurement, non-stationary method for emissivity determination and spectral characterization of thermal source based on their thermal fluxes to the surroundings has been developed.
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Study of behavior of fiber structures under low pressure
Heliová, Magdaléna ; Peterková, Jitka (referee) ; Zach, Jiří (advisor)
The diploma thesis deals with study of behavior of fibrous organic insulants under greatly reduced pressure (even to vacuum). Development, production and durability of vacuum insulating panels are described in the theoretical part as well as principles of heat transfer. Method for production of core of VIP, created using waste fibers from textile industry and agriculture, is described in the practical part. Verification of behavior during normal and reduced pressure (even to vacuum) was carried out on experimentally made core insulants.
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