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Surface modification by means of metallic and polymeric nanoparticles
Steinhartová, Tereza ; Hanuš, Jan (advisor) ; Matoušek, Jindřich (referee)
The theoretical part deals with basic characteristics of low-temperature, low-pressure plasma. It also describes the principles of preparation of polymer and nanocomposite films using this type of plasma. It further explains the basic principles of methods used to characterize our samples. The experimental section shows a technology to produce hard polymeric coatings with metal (Cu) nanoparticles (NPs) fabricated by gas aggregation source (GAS). This approach has an important advantage that Cu concentration and matrix properties can be controlled independently. Characterization of the films in terms of chemical composition, morphology, optical and mechanical properties is described here alongside with description of Cu NPs production using GAS with variable aggregation length. The a- C:H matrix was deposited in a mixture of Ar and n-hexane on the substrates placed on a RF electrode. The beam of the NPs was normal to the substrate plane. In this arrangement it was possible to control hardness of the films and by operational parameters of the GAS also the amount of the NPs in the film. In the last section fabrication of nanocomposite films of titanium and nylon NPs is shown. Powered by TCPDF (www.tcpdf.org)
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Design and optimisation of log rounding process
Iamshchikov, Evgenii ; Trgala, Kamil (advisor) ; Ruman, Daniel (referee)
The subject of my thesis is Design and optimisation of log rounding process. The aim of the work is to develop and explain the changes of the cutting tool parameters of a machine for logs rounding; experimental substantiation for the change of the cutter angle related to the axis of the workpiece. This paper deals with all kinds of wooden housing, from houses of solid wood to houses made of wood-based materials. The description of positive and negative characteristics of each type, including why a house made of logs is essentially different, its positive and negative sides. The paper examines all kinds of the logs rounding technology; the characteristics of their quality and energy consumption are presented. The experimental part of the work consists in the experiment planning and identifying of the factors that influence the rounding process. The way the cutter angle influences the surface roughness during the cylindering process was studied. The final stage of the work was to evaluate the results of the work, their relevance and the possibility to introduce the new equipment with the changed parameters of the cutting tool into production.
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Modelling of flood event runoff and flood lines in Želivka river
Mudra, Jiří ; Roub, Radek (advisor) ; Heřmanovský, Martin (referee)
Nowadays, the issue of floods and flood protection is very reflected theme which is dedicated to the thesis. The first part deals with the gathering and the processing of relevant information, the emphasis is on the development of basic questions about flooding and flood protection because of importance for understanding its. The next part of thesis provides a description of the catchment Želivka which involves the interest area which is bounded swells water reservoir Švihov at 41.6182 Km and dykes of water reservoirs Sedlice at 63.8893 Km. The next, the thesis also discusses the modeling of steady flow of flood flows and modeling flood lines in the area of interest. For the simulation are used ArcGIS 10.2 with overlaid of GeoRAS, HEC-RAS 4.1.0 and the description of creating a model for the assembly are used the digital elevation model fifth-generation, transverse profiles of stream, longitudinal profile of stream and roughness of stream and inundation and geometry of objects on the stream. The outcome of this work are maps of inundation in selected sections on the stream, in particular in areas with existing buildings.
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Sedimentation reservoir on the stream Kuřimka
Holá, Lucie ; Julínek, Tomáš (referee) ; Uhmannová, Hana (advisor)
The goal of the bachelors work is a proposal of sedimentation tank on Kuřimka in the cadestral area of Moravské Knínice. In calculations there was made capacity of addressed section and calculation of levels for thirty-days water and selected N-year flow. One of the chapters was dedicated to evaluation of vegetative suite. For calculations there was used one-dimensional mathematical model HEC-RAS 4.1. Determination of roughness of bottom and slopes was based on personal visit. The result is determination of capacitive flow, evaluation of current state and proposal of sedimentation tank on the chosen estate. Bachelors work can be a contribution to another sedimentation tank in the area of Brněnská dam.
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The study of the influence of process parameters on the roughness of the cut for flame laser cutting of stainless steel
Kučera, Václav ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
Thesis presents a study of the influence of process parameters on the roughness of the cut surface. The test material is 1.4301, namely austenitic stainless steel. When a parameter is the surface roughness not change too much. In some samples there were defects in the form of cutting burrs. The graphs below show the estimated minimum change one parameter (the lowest point of the curve). As the most important parameter from a technological point of view, cutting speed, constitutes a major cost item compared to the auxiliary gas and power. For samples with a thickness of 2 mm and 3 mm has been achieved good results with decrease in the cutting rate of 30% percent, although when cutting the samples with a default rate was almost identical results. For samples with a thickness of 3 mm the best results were achieved by increasing the speed by 30 %, decrease the rate should be compared with the economy of the process to reduce surface roughness. For changes in the gas pressure was achieved the best values at a pressure increase of 30 %. When you change the performance of the best results are achieved by setting 100–90 % capacity.
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Calibration of roughness standards
Šrůt, Petr ; Hammer, Miloš (referee) ; Jankových, Róbert (advisor)
This master´s thesis deals with the measurement of surface roughness on a roundness instrument Talyrond TR595S. The aim was to expand possibilities of measuring on this roundness instrument. The main benefit of this thesis is creation of the proposal for the roughness measurement components in a horizontal and vertical plane. Thesis also includes the procedure for measuring of the roughness of the circular components including calculation of measurement uncertainty.
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Model of surface profile after milling operation with plain milling cutter
Horváth, Ľudovít ; Kubík, Roman (referee) ; Zemčík, Oskar (advisor)
In the teoretical part of the master´s thesis, the master´s thesis deals with milling and surface profile describing. In the practical part, the master´s thesis deal with model of surface profile after milling operation with plain milling cetter. For evalution were used data obtained from the computer model of the surface profil and data obtained from measuring the actual surface profil, which was created by machining the material mills with a diameter of 45 mm.
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Proposal of process control in production safety valve
Jaša, Aleš ; Prokop, Jaroslav (referee) ; Pernikář, Jiří (advisor)
The aim of this thesis is precise definition of control processes for components of Pressure Limit Valve 5 Generation (PLV5) which is produced by Bosch Diesel Ltd. in Jihlava. The objective was to define measurement methods which ensure identical results of measurement between co. Bosch Diesel Ltd. in Jihlava and suppliers of individual components. The results of this study are introduced into control drawings and described in individual conclusions of the thesis.
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The influence of coatings on fracture behaviour of ledeburitic steel
Šafář, Martin ; Jurči,, Peter (referee) ; Hadraba, Hynek (advisor)
This work deals with tool steel Vanadis 6. It describes the preparation of samples for the three-point bending test, with which it examines the influence of surface roughness, the effect of nitriding, coating and duplex coatings on fracture behaviour of the steel. First, it examines bending strength and the total energy required to work of fracture. The work also includes mapping and measurement of surface roughness on different layers. This measurement is performed on a confocal microscope.
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Influence of the wall roughness on discharge coefficient of orifice
Jinek, Josef ; Golík,, Pavel (referee) ; Zachoval, Zbyněk (advisor)
This thesis deals with the influence of the wall roughness on discharge coefficient of sharp-edged circular bottom orifice. It supposed to verify, summarize and extend knowledge of orifice discharge. Author of this thesis determine a discharge coefficient by measurement. Values of discharge coefficient were measured for roughness of the wall represented by different diameters of grains and these values were compared with available values published in specialized bibliography by different scientists. At the thesis end was made a summary evaluation.
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