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Thermal management for mission CIMER
Borovička, Matej ; Lazar, Václav (referee) ; Götthans, Tomáš (advisor)
Táto práca sa zaoberá tepelnou analýzou CubeSatu, pričom vyhodnotenie a následná implementácia výsledkov do samotnej konštrukcie družice je veľmi dôležitá na zabezpečenie správneho fungovania všetkých jej komponentov. V prvej časti je opísaná problematika tepelnej analýzy a návrhy pre vesmírne aplikácie. Druhá časť je venovaná tepelnému návrhu nanosatelitu CIMER, ktorého úlohou je kultivácia cyanobaktérií na nízkej obežnej dráhe Zeme. Sinice majú veľmi špecifické požiadavky, pokiaľ ide o teplotný rozsah, v ktorom môžu prežiť. Táto analýza je preto veľmi dôležitá pre fungovanie celej misie. Práca opisuje vytvorenie tepelného návrhu v softvéri Systema Thermica, jeho následnú analýzu a vyhodnotenie. Nakoniec je model upravený na podmienky potrebné na prežitie siníc vo vesmíre.
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Nuclear power plant condenser design
Havel, Jaroslav ; Kracík, Petr (referee) ; Milčák, Pavel (advisor)
The submitted bachelor’s thesis deals with the design of a condenser for the new Dukovany II nuclear power plant with an electrical output of 1,200 MW. The specified condensation parameters reflect typical parameters of pressurized light-water moderated and cooled reactors of the same power and climatic conditions in the given location. From the assignment of the thesis and the research carried out, the following requirements for the designed device emerged: to ensure the condensation of steam in the secondary circuit in filmwise condensation mode, to comply with the maximum cooling water heating of 10 K, to install the tube bundle at optimum angle and to ensure the competitiveness of the product. For the selected concept with a four-body condenser, a thermal analysis was made and solved numerically by a fixed-point iteration method. The calculation was performed using the EES software. The results showed that a heat transfer surface area of 121,263.96 m is required to ensure failure-free operation of the condenser. Each condenser body consists of 31,400 titanium tubes with a cross-section of ( 22 × 0,5) mm and a length of 14,554 mm. A dimensional drawing is also attached.
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Thermal analysis of fuels
Šrámek, Zbyněk ; Hrnčířová, Michaela (referee) ; Moskalík, Jiří (advisor)
The main goal of this thesis is to introduce the field of thermal analysis as an independent scientific discipline. The first section is mostly informative and introduces into a concept of thermal analysis. The second part describes the most fundamental and essential methods of thermal analysis and the last section is focused on evaluating a real thermogravimetric experiment which deals with biomass sample.
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Comparative performance of late stream inoculants in grey cast iron using thermal analysis
Chyla, Ondrej ; Bouška, Ondřej (referee) ; Roučka, Jaromír (advisor)
This diploma thesis in the theoretical part deals with classification of cast iron, problems of gray cast iron production, methods of inoculation and valuation of the gray iron quality by means of thermal analysis. The aim of practical part was to investigate effectiveness of inoculation of two different inoculants using thermal analysis. In terms of mechanical properties, hardness and ultimate tensile strength were measured. Metallographic specimen were evaluating by means of image analysis software.
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Piston of a spark-ignition engine for 3-D printing
Zelko, Lukáš ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
The goal of the thesis was to design a piston manufactured by conventional method and subsequently adjusted one for additive manufacturing. Beside the designs, thermo-structural model was created for both pistons, considering maximal loading of the engine. Analysis evaluation showed the possibility of further application of the new technology in comparison to current one, within automotive industry.
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Utilzation of physico-chemical analyses in study on microbial stress-response
Slaninová, Eva ; Pekař, Miloslav (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with the utilization of physico-chemical analysis in study on microbial stress–response. The main content of this work was to propose and optimize techniques and methods which are generally used in different industries. Two bacterial strains, Cupriavidus necator H16 and its mutant strain Cupriavidus necator PHB-4 producing polyhydroxyalkanoates (PHA) under certain conditions, were used as model microorganisms. Initially, microscopic teques such as transmission electron microscopy (TEM), cryo scanning electron microscopy (cryo SEM) and atomic force microscopy (AFM) were proposed and tested for the characteriozation of morphological differences of bacteria. Furthermore, viscoelastic properties of bacteria were determined and compared by the oscillatory tests of the rheology method considering another type of samples. Thermal analysis methods, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) in particular, focused on water transport and behavior of intracellular water influenced by presence of the granules of PHB in bacteria. The last technique, utilized in the study, was dynamic and electrophoretic light dispersion during pH changes for characterization of the surface properties of bacteria such as size, zeta potential and the isoelectric point.
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Utilization of physico-chemical analysis in study on cellular water
Matejčíková, Eva ; Obruča, Stanislav (referee) ; Sedláček, Petr (advisor)
The bachelor´s thesis deals with the study of methods, available at the Faculty of Chemistry at Brno University of Technology, that can be used to determine physical and chemical properties of cell water. The main task of this work was to specify which of these methods are suitable to determine physical and chemical properties of water in the cell and the properties of water occuring close to the cell surface. Based on the background research the series of experiments were proposed and implemented. Subsequently, this work deals with the optimisation of methods that were defined as the applicable techniques to determine the properties of cell water.
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Design of structures with FRP reinforcement
Matušíková, Anna ; Vácha, Jaroslav (referee) ; Štěpánek, Petr (advisor)
This diploma thesis presents available FRP software for calculating load bearing capacity of the structures reinforced with FRP and compares them between each other. Furthermore theory and algorithm of my own software is presented here. Load bearing capacity of structures which are reinforced with non-metallic reinforcement and loaded by combination of normal force and bending moment can be solved by my programme. Effects of high temperatures on the concrete structures can be included in the calculation. In the second part of the thesis is calculated load-bearing capacity and deflection of the real beam reinforced with FRP reinforcement and load-bearing capacity of member with FRP reinforcement with effect of elevated temperature. This has been done using my software. Comparison of results from hand calculation and laboratory load-bearing testing is done at the end. This laboratory testing was accomplished by Institute of Concrete and Mansory Structures at our faculty.
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THE APPLICATION OF NANOMATERIALS FOR LEAD FREE SOLDERS DEVELOPMENT
Pešina, Zbyněk ; Pinkas, Jiří (referee) ; Spousta, Jiří (referee) ; Sopoušek, Jiří (advisor)
The present dissertation is motivated by the search for alternatives of lead-free soldering by nanoparticles of metals and their alloys. The research focuses on the possibility of replacing lead-free solders by nanoparticles. This issue is currently being addressed by the use of lead-free solders but their properties are not entirely equivalent to properties of lead-tin based alloys. The theoretical part of the dissertation first summarizes up-to date knowledge on the development of lead-free alloys currently used for soldering in the electronics. The work compares these lead-free solder candidates with previously used Pb-Sn alloys. The second section of the theoretical part is devoted to nanotechnology that offers possible solutions of problems associated with the use of lead-free solders. The text contains a description of the properties of nanocrystalline materials in comparison with those of compact alloys having the same chemical composition. The possibility of preparation of nanoparticles and potential problems associated with small particle sizes are also presented. Introduction of the experimental part focuses on the preparation of nanoparticles of pure metals and alloys by chemical and physical ways as well as on an instrumentation for characterisation and analysis. Attention is focused on the silver in nanoparticle form that exhibits the low temperature sintering effect, which is thermally activated by decomposition of oxide envelope covering the Ag nanoparticles. This factor is critical for low-temperature sintering and thus also for possible future applications. The thermal effects of the low sintering process were studied by methods of thermal analysis. The preparation of the Cu / Ag nano / Cu joints was carried out in-situ in inert atmosphere and under the action of atmospheric oxygen. In both cases varying conditions of thermal treatment were used. The cross sections of the prepared joints were then used for the metallographic analysis of the local mechanical properties of the resulting silver layer, for the chemical composition evaluation of the resulting layers of the joint, and for the microstructure study. Strength characteristics are represented by testing shear strength of individual joints.
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