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Computational modeling of radial hydrodynamic bearings for water machines
Pokorný, Jan ; Šimek,, Jiří (referee) ; Návrat, Tomáš (advisor)
The aim of this thesis is to calculate the stiffness and damping coefficients for radial hydrodynamic bearings. Cylindrical and lemon hydrodynamic bearings are considered. The solution to this problem mainly depends on the hydrodynamic pressure in the bearing. The numerical solution of the Reynolds equation is used to calculate the pressure. The effect of variable viscosity and density of the lubricant due to temperature changes is considered. The static equilibrium position of the journal centre is also solved. The stiffness and damping coefficients are determined using small amplitude journal motions about the equilibrium position. Three methods for determining these coefficients are presented. The outcome of this thesis is an algorithm for the calculation of stiffness and damping coefficients for cylindrical and lemon bearings. Results for lemon bearings are presented and comparison with the commercial software DynRot BR is made. The benefit of this thesis is the creation of an algorithm for the calculation of journal centre equilibrium position, a new way of incorporating the temperature changes in the viscosity and the density of the lubricant, and the modification of a method for calculating stiffness and damping coefficients based on experimental analogy.
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Study of possibilities of optimalization of properties of alternative thermal insulating materials on natural base
Břicháček, Pavel ; Peterková, Jitka (referee) ; Zach, Jiří (advisor)
The presented work investigates the mechanisms of propagation of heat and moisture in the structure of heat-insulating materials based on natural fibers. The main aim of this work is the experimental verification of theoretical patterns, which are involved in the transport of heat and moisture in fibrous materials, especially the influence of fibers thickness and density of the fibrous materials. To widen outputs of the work were selected different kinds of natural fiber materials of vegetable and animal origin. The results of the work should help to optimize the production processes of natural insulation materials considering their optimal thermal properties. From the data collected are deduced general conclusions to better understanding the behavior of these materials.
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Batteries for independent traction
Hladiš, Vítězslav ; Klíma, Bohumil (referee) ; Procházka, Petr (advisor)
The aim of this work is a review of literature of all types of batteries designed for driving in an independent traction (transport). The various types of batteries with them and compare based on their parameters (weight, cost, energy density / kg) to select the appropriate type of battery to drive electric cars, wheelchairs, electric bikes and scooters. The thesis is not a practical product or supplement. This is only a theoretical analysis of the issue.
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Development of ultra lightweight concretes
Popelková, Adéla ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.
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Hranice – redefinition of urban structure
Uherková, Ivona ; Ryšavá, Hana (referee) ; Ponešová, Barbora (advisor)
The diploma thesis Park and Ride deals with the design of a car park in the town of Hranice, which is known mainly for its important transport train node and Hranice Abyss. The city now suffers from the high intensity of car traffic in the city center due to insufficient street network. This network is disrupted by a four-lane road that was built in the 1980s and cut natural transport links. The abolition of the four-lane road, which is now lacking in transport services, releases a large amount of development area, which is primarily used as an agri-recreational area. Part of this green belt is the parking house, which prevents the entry of surplus cars into the city center. The parking house is a new transport hub of the city, which also includes elements of alternative transport - transfer to public transport or bicycle, which makes it possible to create a city center pleasant for pedestrians.
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Accuracy of the determination of liquid viscosity
Zikmund, Ondřej ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This master thesis is focused on the rheological properties of liquids, especially on the viscosity and the standard uncertainty. It explains methods of the viscosity measurement and the calibration selected viscometers, the principle of the determination of standard uncertainty by indirect measurement of the viscosity and the density. The main object of this thesis was to create a specialized centre for viscosity measurement and to create a document which could be used by teaching of diagnostics.
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Incombustible ligtweighting agents for brick body
Suk, Vojtěch ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
This diploma thesis deals with the possibility of reducing the density of the brick body using the chemical additive Vuppor for different types of soil, which are used for the production of thermal insulating products such as type THERM. Describes the availability of suitable additives (starch, carboxymethylcelullose, acrylic dispersion) that are capable of combining with the additive Vuppor to improve the observation properties.
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Influence of dosage of steel fibres on the loss of consistency of fresh concrete and compresive strength of hardened concrete.
Kuře, Václav ; Źalud, Oldřich (referee) ; Vymazal, Tomáš (advisor)
Bachelor work is focused on problems of a consistency of fresh fiber reinforced concrete. The consistency was characterized by a slump test and by a test of spilling how is it described in ČSN EN 12350. Obtained results are compared with a reference sample of a fresh concrete and between themselves. Further the work is focused on volumetric changes during maturation which are integral part of physical properties of the concrete. Influence of a dispersed reinforcement was monitored on the cube strength in plain pressure of individual mixed sample too. Total evaluation of tested parameters is states at the end of the work including comment about possible ways of interference of tests.
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Diagnostics of electroinsulating liquids properties
Makówka, Tomasz ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The diploma thesis deals with the liquid insulators, their properties and their use in the electrical industry. The general aim is to study the physical essence of the dynamic viscosity, the electric conductivity and the diagnostic methods for monitoring these variables. The experimental part contains measuring the dynamic viscosity and the electric conductivity of the mineral transformer oils ESTO BNX, RENOLIN ELTEC and the biodegradable oil MIDEL 7131 during the degradation. The Walden rule is applied on measured results.
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