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Quantification of Hydraulic Descaling Mechanisms
Hrabovský, Jozef ; Toman,, Zdeněk (referee) ; Dobeš, Ferdinand (referee) ; Horský, Jaroslav (advisor)
The issue of descaling is an important part of the forging and heat treatment of steel and semi products of steel production. Rising of new information and study of this process can increase efficiency and improve the surface quality after descaling. This thesis is focused on the mechanisms of the high pressure hydraulic descaling qualification and study of the chemical compounds of which the scales grown. To achieve all goals of this work and to get a comprehensive view of descaling process, few experimental measurements and numerical analyses were performed. All experimental measurements were focused on obtaining data about fundamental parameters and effects of the hydraulic descaling. The data obtained from measurements were applied to numerical analyses, which aimed to discover a deeper relation and to confirm the experimental results. This thesis can be divided into two main parts. The first part is devoted to parameters of the water jet study. The main studied characteristics of the high pressure hydraulic water jet were heat transfer coefficient and impact pressure at different modes such as standard or pulsating water jet. Experimentally measured data of these parameters were applied in numerical analyses. The numerical analyses were focused on studying the impact of the water jet parameters on the stresses in the oxide scale layers. A further water jet analysis was focused on the influence of the individual parts of the hydraulic system (such as water chamber or stabilizer) on its characteristics. In this part different types of the water chambers in combination with different types of stabilizers on the impact pressure values were investigated. These measurements were supported by fluid flow analysis through the hydraulic system. The second part of this work was focused on getting mechanical properties of the oxide scales from specimens prepared from standard structural steel and specimens from silicon steel. In this thesis, the influence of various parameters and characteristics was studied on these two types of steel. Mechanical properties of oxide scale structures were carried out by the Small Punch Test method. To obtain the fundamental mechanical properties such as Young´s modulus, yield strength and ultimate strength, material parameters based on the measured data were optimized. The whole work was carried out in order to get valuable and comprehensive results about high pressure hydraulic descaling process and influencing factors as well as about oxide scales themselves.
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Quantification of Hydraulic Descaling Mechanisms
Hrabovský, Jozef ; Horský, Jaroslav (advisor)
The issue of descaling is an important part of the forging and heat treatment of steel and semi products of steel production. Rising of new information and study of this process can increase efficiency and improve the surface quality after descaling. This thesis is focused on the mechanisms of the high pressure hydraulic descaling qualification and study of the chemical compounds of which the scales grown. To achieve all goals of this work and to get a comprehensive view of descaling process, few experimental measurements and numerical analyses were performed. All experimental measurements were focused on obtaining data about fundamental parameters and effects of the hydraulic descaling. The data obtained from measurements were applied to numerical analyses, which aimed to discover a deeper relation and to confirm the experimental results. This thesis can be divided into two main parts. The first part is devoted to parameters of the water jet study. The main studied characteristics of the high pressure hydraulic water jet were heat transfer coefficient and impact pressure at different modes such as standard or pulsating water jet. Experimentally measured data of these parameters were applied in numerical analyses. The numerical analyses were focused on studying the impact of the water jet parameters on the stresses in the oxide scale layers. A further water jet analysis was focused on the influence of the individual parts of the hydraulic system (such as water chamber or stabilizer) on its characteristics. In this part different types of the water chambers in combination with different types of stabilizers on the impact pressure values were investigated. These measurements were supported by fluid flow analysis through the hydraulic system. The second part of this work was focused on getting mechanical properties of the oxide scales from specimens prepared from standard structural steel and specimens from silicon steel. In this thesis, the influence of various parameters and characteristics was studied on these two types of steel. Mechanical properties of oxide scale structures were carried out by the Small Punch Test method. To obtain the fundamental mechanical properties such as Young´s modulus, yield strength and ultimate strength, material parameters based on the measured data were optimized. The whole work was carried out in order to get valuable and comprehensive results about high pressure hydraulic descaling process and influencing factors as well as about oxide scales themselves.
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CONSTRUCTION DETAILS FROM SECONDARY RAW MATERIALS USED FOR BUILDING ENVELOPE
Smolka, Radim ; Rybárik,, Ján (referee) ; Schmid, Pavel (referee) ; Šinogl,, Jiří (referee) ; Matějka, Libor (advisor)
One of the important reasons for the choice of the thesis topic are increasing requirements from the persons interested in low-energy, passive or even houses with almost zero energy consumption. During decreasing of the energy demand is within the framework of the idea of sustainable construction not only required to decrease the total energy demand of the buildings, search and solve the critical spots in the building jacketing, but also to use the secondary raw materials as full-value substitutions for commonly used products from the primary raw materials. The thesis tries to contribute to the possible usage of polymeric wastes in building industry. In an early stage of the thesis the main and partial targets together with the consecutive steps leading to their fulfilment were set. Selection of the suitable secondary raw materials, discussion with the specialists, initial sample mixing, finding their thermally – technical characteristics, press mould and fire kiln acquisition was carried out during the stage. The next phase is focused on the application of the products made from the secondary raw materials to the building envelope. The products are moulded according to the thermally – technical properties. Performed moulding approved that the products are fully functional and after reaching the required value of heat conductivity coefficient products eliminate imperfections of the solutions used at present. Strapping product for the threshold door joint is registered at Industrial Property Office of the Czech Republic and at European Patent Office at the same time. Recycled materials put into production represent possibilities how to decrease number of acquired virgin materials, need of primary energy and how to decrease risks connected to the waste disposal. Society is starting positively approaching to the products that are partially or fully produced from the secondary raw materials. Nevertheless, before the products from the recycled materials enter the peop
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Using Optimization's Algorithms by Designing of Structures
Fedorik, Filip ; Keršner, Zbyněk (referee) ; Haapala,, Antti (referee) ; Dický,, Jozef (referee) ; Kala, Jiří (advisor)
The application of optimization algorithms in the design of many economical and industrial problems currently represents a significant assignment. The development of high-powered computers allows an application of difficult mathematical techniques and physical phenomena to simulate real problems with sufficient accuracy. The optimization techniques used in engineering designs are mostly represented by modified mathematical programming methods with extension of their usability. The aim of the presented thesis "Using Optimization´s Algorithms by Designing of Structures" is to analyze the applicability of optimization procedures which are available in the widely used computing system ANSYS in civil and mechanical engineering practice. The numerical analyses were performed within the frame of multi-extreme, one to three dimensional optimization problems, multi-dimensional problems expressed by minimizing the weight of a truss beam and efficient design of air gap location in wooden studs from the point of view of thermal features of the structure. The analyzed optimization processes are in plurality verified with accurate manual computing and graphical solutions and the accent is put on optimization methods´ possibilities to improve robustness, efficiency and accuracy of the optimization algorithms in civil engineering problems´ designs. The optimization methods represent a suitable approach to improve the efficient design of a wide range of civil and mechanical engineering structures and elements. By combination of their advantages and FEM/FEA method it is possible to achieve very good results, although robustness of the solutions is not guaranteed. The robustness and accuracy of the procedure could be increased by competent exploration of design space and suitable selections of optimization methods´ features.
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Public Spaces of the Historic City Center of Brno - SQUARES
Vaculíková, Petra ; Doc.Ing.arch.Irena Fialová (referee) ; Kroupa, Petr (referee) ; Rudiš, Viktor (referee) ; Pelčák, Petr (advisor)
Changes of physical, functional and social structure of the city as a result of the group of variously interrelated changes and events that are fundamentally participate in the formation of the image of the urban development. This doctoral thesis is based on research of the historical city center - squared. First part is focuses on the historical development of urban texture of the inner city of Brno and its squares. We are talking about Square of Freedom, Vegetable Market, Dominican square, Jacobs square, Capuchins square and Šilingrovo square. Based on individual characteristics, describing the emergence of morphological and functional changes in Brno square was created urban classification of basic types of square. City of Brno, as the capital city of region has a significant position in the structure of settlements. This fact has become one of the key aspects for the selection of examples of European cities and their squares. The second part of the thesis is based on comparative studies of different types of historical squares. In order to define the value of public spaces, it is necessary to look at the public places of historical perspective and deal with the causes that led to the decline of the importance and role of public spaces. Austrian capital cities of region (Graz, Linz, Klagenfurt and Salzburg) will be examined with regard to similar climatic conditions and a common cultural and historical context of the city. Based on urban patterns and graphic diagrams of each square are observed inner relationships between shapes of square, form, function and location of the position of an artwork. Research areas are also focused on comparing aspects of transport, green space, functional use, visual unit and social activities. The public space is shaped by a set of characteristics that promote diversity and interdependence of functions. For a better interpretation of the results have been established two benchmarks - symbol of identification with the place and the Magnet (function and filling space). The objective of the thesis is to define an aspects and elements of space which were involved in square use.
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Fine set-up of the Ar-Ion laser and fibre loader
Konfršt, Jiří ; Kysela, Bohuš ; Chára, Zdeněk
Use of lasers in the measuring systems, which use LDA/PDA devices, expects good knowledge of physical characteristics of used light source namely for multicomponent measurements. This article is focused on the experimental parameter analysis of individually separated light wavelength from Ar-Ion plasma tube, working in multiline “ML” mode. The best laser source parameters: aperture size, power input and quality of the utilized separate wavelengths were obtained and beams were adjusted to the optical fibres.
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The changes of transport flows and accesibility in Pilsen region in relation to the settlement system
Brož, Petr ; Marada, Miroslav (advisor) ; Květoň, Viktor (referee)
The issue of transport is currently one of the most discussed topics, thanks to deepening regional differentiation causing increased demands on the quality of existing transport links. Especially the attractiveness of centers and the existence of good transport infrastructure, stimulating the development of the region (his success), is becoming one of the most debated issues of our times. This diploma thesis deals with the comparison and evaluation of changes in spatial interaction in the settlement of the Plzeň/ Pilsen region in two time slices (1991 and 2001). Analysis of the interactions of traffic will be done by using statistical methods and using GIS technology. Main attention will be paid to the spatial differentiation of the frequency of traffic flows and transport accessibility. Subsequently, the transport characteristics will be compared with the characteristics of the complex importance of settlement, so the basic relationships between these indicators can be found. Keywords: spatial interaction, accessibility, frequency of public transport, traffic flows, transport regionalization, Plzeň/ Pilsen region.
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Preparation of Nanocomposites TiOx /Plasma Polymer and Study of Their Properties
Drábik, Martin ; Biederman, Hynek (advisor) ; Čech, Vladimír (referee) ; Špatenka, Petr (referee)
Title: Preparation of Nanocomposites TiOx/Plasma Polymer and Study of Their Properties Author: Mgr. Martin Drábik Department: Department of Macromolecular Physics Supervisor: Prof. RNDr. Hynek Biederman, DrSc. Supervisor's e-mail address: bieder@kmf.troja.mff.cuni.cz Abstract: This thesis concerns a study of nanocomposite films TiOx/plasma polymer prepared by various deposition techniques using different organic precursors. Processes of deposition of the films were diagnosed in-situ by means of OES and measuring the deposition rate by QCM. Properties of the nanocomposite films were studied by various characterization techniques. Wettability of the films was described by means of the contact angle of water. Morphology of the nanocomposites was characterized by AFM, TEM and SEM. Elemental analysis and chemical composition of the films were studied by XPS, RBS, SIMS and FTIR. Crystal structure of TiO2 films was identified by XRD. Optical characterization of the prepared films was done by UV-Vis spectroscopy. Electrical properties of the samples were characterized by I-V and SPV measurements. In the end, 'wet' chemical processes were utilized for preparation of both TiO2 nanostructures and organic films for comparison with vacuum deposition techniques and plasma polymer composite films. Keywords: nanocomposite...
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The Development of Local Government in the Municipality of Podlesí
Kolaříková, Martina ; Kubálek, Michal (advisor) ; Marek, Marek (referee)
The thesis deals with the development of local government in the village of Podlesí. The village of Podlesí is situated in the Central Region, approximately two kilometers from the town of Pribram. On December 31, 2015, it had a population of 1 097 inhabitants. The main objektive of this study was to identify factors that influence the character of the local political process in the village of Podlesí. This is a case study that shows the development of the local political process here from 1990 to 2014. Working initially in the theory explains the concepts related to public administration, local authorities, the function of elections and electoral systems, municipal electoral systém and the local political process. The practical part describes the village of Podlesí. This description includes Podlesí´s history, its development of demographic characteristics and social amenities. After that an individual comparison of individual results of municipal elections from 1990 to 2014, personal interviews with local political figures and defined the character of local political processes in the village of Podlesí.
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The Development of Local Government in the Municipality of Žíšov
Koubová, Markéta ; Bubeníček, Václav (advisor) ; Michaela, Michaela (referee)
This master thesis deals with the development issues of local authorities in Žíšov (South Bohemian region). The thesis is divided into 2 part - theoretical and practical. The theoretical part describes the characterization of municipal administrative bodies, municipal electoral process and local partisanship. This part also deals with the characterization of typology of local partisanship systems according to Petra Jüptner and Václav Bubeníček, citizen participation of political life and splitting within communities. The practical part of this thesis describes the basic demographic characterization of Žíšov and its history at first.
Another researched part describes the problems of socioeconomic indicators of the village (Žíšov). The key part is the analysis of election period during 1994 - 2014 with detailed look into each year. The conclusion of this thesis is the nature of local politics.
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