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Computer modeling of twin-boundaries in shape memory alloys
Heczko, Martin ; Pokluda, Jaroslav (referee) ; Zelený, Martin (advisor)
This Master‘s thesis is focused on theoretical study of twinning in magnetic shape memory alloys based on Ni2MnGa using ab initio calculations of electronic structure within the projector augmented wave method. In particular, the effect of increasing concentration of manganese at the expense of gallium was studied on total energy and stress profiles along different deformation paths in the (10-1)[101] shear system of non-modulated martensite. Further, this work deals with the effect of the concentration of manganese on the energy of planar fault caused by presence of partial dislocation due to motion of twin boundary. The results show that the shear modulus in studied shear system increases with the increasing concentration of manganese as well as energy barrier and deformation characteristics along shear deformation paths increases, which makes the shear more difficult in Mn-rich alloys. Increasing concentration of manganese also leads to rising the planar fault energy. All these effects can be responsible for lower mobility of twin boundaries in alloys with higher concentration of manganese.
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Strucure and mechnical properties of cold sprayed Ti-6Al-4V layer
Sabela, Jakub ; Zelený, Martin (referee) ; Řehořek, Lukáš (advisor)
Diploma thesis deals in the first part with recent knowledge of cold spray, its mechanism and parameters of deposition, advanced coatings made by cold spray and their applications, knowledge of Ti-6Al-4V coatings and their heat treatment. Deposit of Ti- 6Al-4V powder was made by cold spray process. In experimental part, microstructure and mechanical properties of supplied and its heat treated material were observed and examined. Mechanical properties and microstructure remained unchanged by annealing at 600 °C as in the case of supplied material. Recrystallization occured in microstructure of and phases by annealing at 800 °C. Grains were emerged in microstructure and mechanical properties were decreased. Mechanical properties were improved by annealing at 900 °C due to quenching. Microstructure consists of and ’ phases. Mechanical properties were the worst for annealed material at 1000 °C because of coarsed grains. Material which was annealed at 800 °C, quenched and precipitation hardened had the best microstructure and mechanical properties.
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Computational prediction of solubility limits in solid solutions
Fikar, Ondřej ; Friák, Martin (referee) ; Zelený, Martin (advisor)
This diploma thesis is focused on a theoretical study of the phase stability of solid solutions in selected aluminium and silver alloys. The ab initio calculations were performed using projected augmented waves method and the thermal dependencies of thermodynamic quantities were acquired using phonon calculations. The main focus of this work is the of aluminium-germanium alloy, while the other examined alloys (Al-Pb, Ag-Ge and Ag-Pb) serve the purpose of comparison of the solid solubility prediction and its reliability in systems with different composition. The temperatures, at which the solid solutions become stable, were evaluated using the energy difference between possible states and this evaluation was carried out for different contributions to the total energy. Also the electronic and phonon densities of states were calculated for all pure elements and solid solutions. The temperatures of solubility were compared to the experimental ones provided by the CALPHAD method and the individual contributions to the total energy were determined and depicted. The results obtained in this work tend to underestimate temperatures of solubility of individual solid solutions by hundreds of Kelvin.
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Socioeconomic passportization of immovable cultural heritage
Kouba, Vojtěch ; Lindner, Milan ; Vořechovský, Jan ; Dostál, Petr ; Pátek, Zdeněk ; Dianová, Markéta ; Titelbachová, Šárka ; Tyslová, Irena ; Straka, Michal ; Zelený, Martin ; Kubaš, Mario ; Hanzlík, Jan ; Vančurová, Alena ; Vond, Zdeněk
Předkládaná metodika je výsledkem aplikovaného výzkumu a je zaměřena na ekonomiku památek, resp. nemovitých objektů prohlášených kulturními památkami České republiky. Jejím cílem je vytvoření pasportů ekonomických hodnot pro jednotlivé památkové objekty, v případě využití metodiky orgány veřejné správy i pro soubory památek určitého druhu či soubory památek na vymezeném území.
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Magnetic shape memory alloys - ab initio approach
Heczko, Martin ; Šesták, Petr (referee) ; Zelený, Martin (advisor)
This Bachelor’s thesis is focused on theoretical study of magnetic shape memory alloys based on Ni2MnGa using ab initio calculations of electronic structure within the projector augmented wave method. In particular, the effect of increasing concertation of manganese instead of gallium was studied on total-energy and magnetic moment profiles along the tetragonal deformation path between austenite phase with cubic L21 structure and phase of nonmodulated martensite. Further, the effect of manganese atoms distribution within the gallium sublattice was studied as well as changes of this distribution under applied tetragonal deformation. At last but not at least, the elastic constants for austenitic and martensitic structures of studied alloys were calculated. The results show that the non-modulated martensite stabilized with increasing concentration of manganese, because its total energy decreased. The energetic barrier between austenitic and martensitic structures also decreased, which means the metastable austenite will change to unstable.
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Ab initio calculation of doping in Ni2MnGa alloy
Janovec, Jozef ; Černý, Miroslav (referee) ; Zelený, Martin (advisor)
Cieľom tejto práce je teoretické štúdium systému Ni-Mn-Ga, vykazujúceho efekt magnetickej tvarovej pamäti. Pri výpočtoch bola použitá metóda Exaktných Mufiin-Tin Orbitálov v kombinácii s aproximáciou koherentného potenciálu vrámci Korringa-Kohn-Rostoker formalizmu. Totálna energia bola spočítaná pomocou metódy úplnej nábojovej hustoty. Skúmaný bol vplyv dopovania zinkom alebo kadmiom na totálne energie pozdĺž tetragonálnej deformačnej dráhy a následne na teplotu martenzitickej premeny TM a Curieho teplotu TC. Taktiež boli skúmané nestechiometrické zliatiny prebytkom Mn na úkor Ga. Výsledky predikujú nárast TM po všetkých pozorovaných substitúciách v podmriežke Ga a pokles TM po substitúciách v podmriežke Mn. Curieho teplotu znižujú všetky študované substitúcie s výnimkou zmeny magnetického usporiadania v martensite nestechiometrickej zliatiny.
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The impact of marketing strategies on film viewer’s decision
Kudrnová, Anna ; Hanzlík, Jan (advisor) ; Zelený, Martin (referee)
The aim of this bachelor theses is to find out the most effective film marketing tools. Is it a movie poster that affects the decisions of the young generation when choosing a movie? In the empirical part, the thesis will deal with the general possibilities of marketing tools applicable to the film industry. The practical part will be based on a questionnaire survey which will be based on an interview with a film marketing expert.
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EU-SILC Indicators International Comparison
Trezzi, Bohdana ; Mazouch, Petr (advisor) ; Zelený, Martin (referee)
This thesis is focused on comparison of selected indicators within EU-SILC and project Europe 2020. Data for analysis were used from databases of Statistical Office of the European Union (Eurostat). Following selected indicators are analysed: employment rate, people at risk of poverty or social exclusion, life expectancy. Trend-cycle series are used for analysis of selected indicators and values predicted for the year 2020 which are then compared with project Europe 2020 goals for countries the Czech Republic and Germany and in this way setting of these goals validated.
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Market of Physical Media in the Field of Film and Music
Kratochvílová, Lucie ; Hanzlík, Jan (advisor) ; Zelený, Martin (referee)
The bachelor thesis is devided into two parts, a teoretical one and a practical one. One chapter of the teoretical part deals with the development of physical media in the field of film and music with an overlap to online distribution and the current state of the physical media market. Another chapter of the thesis is devoted to legislation in this field. The last chapter of the theoretical part is devoted to the influence of corporations on the market with physical media and marketing strategies. The main content of the practical part is quantitative research, which identifies patterns of behaviour in purchasing physical media today. The information obtained is interpreted in the form of graphs with the comprehensive description. The outcome of the research is a definition of a typical customer who, based on the answers I get, most often purchases physical media.
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