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Study of properties of laser welds of Hardox 450 material using arc preheating
Debs, Martin ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
In this thesis is studied the influence of arc TIG preheating during laser welding of 2 mm Hardox 450 material sheets. This material achieves its good mechanical properties by processes of heat treatment. That causes problems during welding because of heat degradation. Experimental sheets were welded within various configurations of welding parameters and positions of TIG nozzle. Testing specimens were cut out by laser and were used for tension testing, Vickers hardness testing and metallographical testing (macro and microstructure). The results of using the second heat source are: wider heat affected zone, smoother transitions among its zones, reduction of toughness and hardness, finer grain structure and occurring ferritic microstructure. This hybrid technology, combination of laser welding and TIG preheating, is very productive creating joints with greatly good quality. The thesis also contains a comparison with common MAG welding method.
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Implementation of automatic welding machine to production of fittings
Cícha, Tadeáš ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
The Diploma Thesis is focused on the implementation of FCAW welding technology to the manufacturing process of a mechanical engineering company. One part of implementation is partial automation of manufacturing process with positioner machine which is connected to the welding source. Practical part of Diploma Thesis includes the verification of the weldability of used materials and assigning of pWPS for subsequent qualification of the welding process WPQR with the welding technology FCAW.
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The repair procedure of the press frame
Švarc, Lukáš ; Daněk, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The diploma thesis is dealing with the repair procedure of the cracked ram of the press – machine parts made from gray cast iron by casting. The ram is a part of the repaired forming press LET 160. The presented work contains an overview and analysis of the technologies of repair of cast iron by welding. On the basis of the theoretical part is designed the procedure of repairing. The aim of the experimental tests is selecting the most suitable additional materiál and verifying the proposed welding process. The welding method was selected by a low preheating manual metal arc. All the pWPS were prepared for the welding of all test specimens. Experimental samples were subjected to visual, macroscopic, microscopic analysis and hardness measurement. Based on the results of the experiments was suggested a welding repair procedure with a pWPS.
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Handicap as a Gift
Beran, Radek ; KLÍMA, Miloslav (advisor) ; KUBÍČEK, Jiří (referee)
In my thesis the potential of technical struggles and various mechanical limitations of puppets themselves is explored. Related to that also other limitation of puppetry and even drama as a genre itself are uncovered. Surprising analogy with the world of people with disabilities can be found here. So a disabilitity becomes a substantial point of view and a kind of subjects of demonstration which have been used in my work up to now. In the first part resources and terms related to disabilities are considered as well as the reasons triggering my interest in this phenomenon. A particular project subconsciously drew my attention to my higher sensitivity to various forms of disabilities in life and art as well
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SPECIFICS OF CREATING SOUND DESIGN OF ANIMATED FILM
Karhánková, Kateřina ; KUBÍČEK, Jiří (advisor) ; GREINER, Ladislav (referee)
The thesis explores the production of sound for animated film – its specifics as well as aspects of realization and of preparation and audio dramaturgy. It examines how they impact storytelling and the extent to which it is possible and useful to work with them from the very beginning of development of an animated film. The thesis also presents the practical and creative possibilities of cooperation between director and sound designer, alongside factors that may have a positive or negative influence in this regard. It draws on literary sources, interviews with the makers of animated films and knowledge acquired by the author in the field of directing and screenwriting of animated films. The thesis confirms the importance of the role of sound in animated film and its positive influence on the resulting quality of AV work (unless it has been omitted from the start of the filmmaking process). It summarizes the basic approaches that allow animators to work with sound in animated film as a fully-fledged narrative component.
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Optimization of surface treatment of stainless steels
Mačátová, Lucie ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The project deals with the processes of degreasing industry and testing new laser cleaning process, which has been experimentally verified and tested in the production process. Project also deals with soldering in general as a technology of joining metals. Included are the main components of the soldering, such as solder, flux, the types of connections and their use, ways of soldering and last but not least the soldering corrosion-resistant steel.
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Gravitation in higher dimensions
Kubíček, Jan ; Pravdová, Alena (advisor) ; Žofka, Martin (referee)
The thesis starts with a brief introduction to the algebraic classificati- on of tensors and spacetimes in higher dimensions. Attempts to generalize the Goldberg-Sachs theorem are also discussed. There is a summary of main results for optical matrices of algebraically special spacetimes in higher dimensions. The optical matrix for a type III spacetime in six dimensions is found using Bianchi identities. A few properties of type III optical matrices in a general dimension are also found. Various properties of equations obtained from Bianchi identities for type III spacetimes are studied in appendices. 1
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The Tabloid's development in Czech Countries
Dorčáková, Jana ; Köpplová, Barbara (advisor) ; Kubíček, Jaromír (referee) ; Machek, Jakub (referee)
This thesis describes the beginnings of tabloid dairies in Czech countries. In addition to the overall analysis of the monitored titles, thesis offers a comprehensive look at the issue of tabloid newspapers, its characteristics and its inclusion to the popular culture. The research period is from 1879 to 1939. Thesis describes the socio-cultural character studied period, which led to the formation of the first tabloid newspaper. We compare the development of Czech tabloid dairies with the development of those newspapers in Germany, Austria, Great Britain, France and the USA. We compare the tabloid also with serious contemporary newspapers. Results of this work is the periodization of Tabloid paper at the Czech territory, its character, the mutual differences and character of its readers.
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Laser cutting
Baran, Marek ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The thesis elaborates cutting of thick sheet metal using the laser technology. Beside technological aspects of laser cutting, the project also deals with utilising laser technologies in practice and compares laser cutting to other ways of cutting sheet metal. The experimental part, which was realized in STEELTEC CZ, was concerned with optimization of focal point for cutting 20 mm sheet metal of S235JR. The samples which were cut on a CO2 laser were compared to samples made by plasma and water cutting machines. The researched parameters were roughness, shape, time and price.
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Comparison of the thermal influence by TIG method
Pavlas, Jan ; Daněk, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The presented bachelor thesis deals with arc welding of stainless steels by welding method TIG. It compares the influence of pulse and DC current on the welded component. Introduction analyzes the influence of arc welding on metallic materials, heat introduced into the weld and the heat affected area. Two experiments on S235JR and 1.4301 steel were performed to verify theoretical assumptions. The effects of current on the material were evaluated using the analysis of the tests and the calculation and the conclusions were made. Finally I made recommendations for practice and possible further research on the issue.
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