National Repository of Grey Literature 168 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
From deposition to caldera resurgence: pyroclastic density current dynamics as revealed by magnetic anisotropy of the Teplice rhyolite, Bohemian Massif
Vitouš, Petr ; Tomek, Filip (advisor) ; Mlčoch, Bedřich (referee)
Better understanding of pyroclastic density current (PDC) dynamics is one of the key volcanological focuses, as PDCs represent one of the most life-threatening volcanic hazards. PDCs associated with explosive collapse calderas are difficult to observe and examine directly, and thus research of internal architecture of calderas and their PDC deposits is focused on extinct and partly eroded volcano-plutonic systems. Such a case is the Late-Carboniferous Altenberg-Teplice caldera in NW Bohemian Massif, which exposes a large body of ignimbrites (deposits of the PDC) called Teplice rhyolite (an intra-caldera fill). This body is well exposed on the southern flank of the Krušné hory/Erzgebirge Mts., mainly its members: Teichweg, Lugstein-Pramenáč, Vlčí kámen-Medvědí vrch and Přední Cínovec. As these ignimbrites appear macroscopically isotropic, I employed the Anisotropy of magnetic susceptibility (AMS) in order to quantify their internal structure. A total of 1232 specimens from 63 sampling stations were analyzed for the AMS, complemented by susceptibility vs. temperature variations and petrographic observations. Obtained AMS data, carried by a mixture of paramagnetic ferrosilicates and low-Ti titanomagnetite, indicate various processes recorded in ignimbrites. The relatively oldest and moderately welded Teichweg...
Design and manufacture of bending fixture
Ševčík, Jan ; Trčka, Tomáš (referee) ; Zemčík, Oskar (advisor)
The work deals with the design and manufacture of bending fixture. It contains a comparsion with current bending fixtures on the market and a justification for the production of a given type. Then the work contains a proposal of the constuction of individual parts with the selection and description of technologies of their production and the process of their production. The work also contains complete drawing ducumentation of all parts of the bending fixture. The conclusion of the work contains the possibilities of design modifications and economic and technological evaluation.
Replica of historical dagger
Čech, Jakub ; Chladil, Josef (referee) ; Kalivoda, Milan (advisor)
This bachelor’s thesis deals with a production of dagger replica. This work describes basic information about history of daggers, their construction and technologies used for their production. Furthermore, there is described manufacturing of the dagger prototype including its final assembly and evaluation.
Feasibility Study of the Multi-Purpose Area Combining Cafe and a Motorcycle Rental Shop
Drkoš, Jan ; Schüller, David (referee) ; Chlebovský, Vít (advisor)
This diploma thesis focuses on the topic of feasibility studies. The first-theoretical part defines basic concepts such as market analysis, financial analysis or efficiency and risk assessment. The aim of the practical part of the work is to develop a feasibility study, evaluation of economic viability and thus the feasibility of the project. An integral part is the evaluation of welding methods of the steel frame of the motorcycle and its subsequent implementation.
Inspection of welded joints of loading ramps
Ertl, Roman ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
This master's thesis is focused on problem of welding of loading ramps and inspection of their welded joints. The aim of this thesis is to inspect the welds of loading ramps with regarding to the appearance of defects. The literature review of the research issues of the MIG welding technology and welding of aluminium and its alloys is described in this thesis. There is also described destructive and non-destructive inspection of welds that can be applied to inspection of loading ramps. Theoretical description is followed by an experimental part of the thesis. Experimental part is focused on the three destructive tests (the tensile, the macroscopic and the hardness test) of samples of loading ramps, which are made of EN AW-6005A T6.
Welding of martensitic stainless steel using hybrid technology Laser - TIG
Novotný, Jan ; Sigmund, Marián (referee) ; Mrňa, Libor (advisor)
Theoretical part of this thesis includes overview of laser welding technology and possible combinations with arc welding methods for meeting desired properties of the weld. It also explains mechanical testing and metallographic examination on welds. The experimental part deals with optimisation of process parameters during welding of martensitic stainless steel, used in energetic industry using hybrid laser - TIG technology in regard of mechanical properties of the weld, its structure and proposal of technological parameters.
Welding of deep-drawing steels with a protective layer by means of an oscillating laser beam
Holub, Kamil ; Sigmund, Marián (referee) ; Mrňa, Libor (advisor)
This thesis deals with the topic of procedural parameters influence on the properties of welded joint in zinc-coated deep-drawing steels in laser welding with wobbling. First part of the thesis serves as an overview of laser welding technology, welding of steel with protective zinc layer and weld quality testing. Second part is dedicated to a proposal, process flow and evaluation of an experiment. Seven trial lap welding joints of DC04+ZE steel have been welded using different welding parameters. Specimens from these trial welds were used for metallurgical testing by macro-etch examination and for tensile strength break testing to get mechanical properties of welded joints.
Renovation of casting molds by laser cladding technology
Cicha, Tereza ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
The diploma thesis deals with study of laser cladding technology and possibilities of its use in renovation of casting molds made of hot-work tool steel. The theoretical part describes methods of laser cladding, testing methods and characteristics of the base material and its heat treatment. In the experimental part the test clads, and the metallographic samples were made. The samples were evaluated in terms of macrostructure and microstructure, especially clad geometry, dilution, and defects like pores and cracks. Microhardness was also measured. In conclusion a technical and economic evaluation was performed.
Utilization of laser welding methods for fixation of electrotechnical sheet bundles
Adam, Tomáš ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
Thesis deals with individual technologies of packaging stator sheets and their use in practice. The greatest emphasis is placed on welding technologies, especially on the differences between the individual methods. The experimental part of the thesis is focused on finding suitable parameters for welding the stator package using a laser with a special wobling head. The samples were evaluated in terms of penetration depth, the number of defects, especially pores and grain coarsening.
Welding thin-walled pipes made of stainless steels
Naď, Tomáš ; Sigmund, Marián (referee) ; Kubíček, Jaroslav (advisor)
The bachelor's thesis deals with technology of welding of thin-walled stainless steel pipes and the analysis of weldability of stainless steels. The theoretical part provides a basic description of the material's weldability and the basic defects in welding, the characteristics of stainless steels, their division, marking, alloying and a general overview of their weldability. The experimental part describes selected welding technologies used for the production of thin-walled stainless steel pipes (LBW, PAW, HFIW). Finally, the technology used to weld the presented samples of thin-walled pipes is ascertained and the macrostructure of the weld are compared.

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