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FRP for concrete reinforcement
Blahová, Aneta ; Vaněrek, Jan (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with composite polymer FRP reinforcement. It descibes the method of manufacturing FRP reinforcements, which are their properties and what materials are used by manufacturers. Lists FRP reinforcement application in various structures. Also mentions the durability of FRP reinforcement in an aggressive environment and the cohesiveness of FRP reinforcement with concrete. The conclusion of the work is a proposal for experimental testing of a bond between FRP reinforcement and concrete.
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Conservation of glass mosaics in epoxy bedding
Viková, Barbora ; Vojtěchovský, Jan ; Hampl, Petr ; Svoboda, David ; Kučerová, Irena
The procedure focuses on the conservation of glass mosaics from the second half of the 20th century, which were embedded into epoxy resin as part of the original technology. The advantage was to create light, easily transportable structures (panels). Various materials were used for the base of these panels, such as steel reinforcement, aluminium plates, but also chipboard plates. Over time, the epoxy bedding proved to be unstable, especially in outdoor conditions, where it often degraded or completely disintegrated. It was therefore necessary to consider replacing the original bedding material with a new one. The replacement of the support is illustrated in the conservation of three mosaics, namely a glass mosaic with chipped tesserae, which is an example of an epoxy-coated mosaic with an embedded metal structure, and two mosaic of crumpled tesserae representing a mosaic glued with an epoxy resin to the chipboard. For both types of mosaics a brand new, more stable mosaic embedding system has been developed.
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Preparation and properties of building blocks of specialty polymers
Šichová, Kristýna
This Diploma Thesis presents results obtained by solution of two partial projects: a) Preparation of monomers from renewable sources using metathesis and tandem hydrogenation catalyzed with ruthenium compounds - project solved during my Erasmus stay at the Université de Rennes 1 in France; b) Preparation and properties of ,-bis(tpy)quarterthiophene oligomers carrying ionic side groups as oligomonomers for polyelectrolyte conjugated dynamers - project solved at the Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague. Project a): Self-metathesis of 1,2-epoxyhex-5-ene (but-3-enyloxirane) and its cross-metathesis with methyl acrylate and acrylonitrile catalyzed with ruthenium compounds as well as tandem design of these metatheses and consecutive hydrogenation of their products by gaseous hydrogen have been optimized. The following influences have been studied and tuned: (i) type of the catalyst (Grubbs, Hoveyda, Zhan) and its concentration and method of dosing, (ii) concentration of reactants and additives, (iii) type of solvent, and (iv) reaction temperature. Reactions were monitored by the GC, GC and MS methods and the products were characterized by the NMR method. Methyl 6,7-epoxyheptanoate (methyl 5-oxiranylpentanoate) obtained by the tandem...
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Preparation and properties of building blocks of specialty polymers
Šichová, Kristýna ; Svoboda, Jan (advisor) ; Sedláček, Jan (referee)
This Diploma Thesis presents results obtained by solution of two partial projects: a) Preparation of monomers from renewable sources using metathesis and tandem hydrogenation catalyzed with ruthenium compounds - project solved during my Erasmus stay at the Université de Rennes 1 in France; b) Preparation and properties of ,-bis(tpy)quarterthiophene oligomers carrying ionic side groups as oligomonomers for polyelectrolyte conjugated dynamers - project solved at the Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague. Project a): Self-metathesis of 1,2-epoxyhex-5-ene (but-3-enyloxirane) and its cross-metathesis with methyl acrylate and acrylonitrile catalyzed with ruthenium compounds as well as tandem design of these metatheses and consecutive hydrogenation of their products by gaseous hydrogen have been optimized. The following influences have been studied and tuned: (i) type of the catalyst (Grubbs, Hoveyda, Zhan) and its concentration and method of dosing, (ii) concentration of reactants and additives, (iii) type of solvent, and (iv) reaction temperature. Reactions were monitored by the GC, GC and MS methods and the products were characterized by the NMR method. Methyl 6,7-epoxyheptanoate (methyl 5-oxiranylpentanoate) obtained by the tandem...
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Drying and preheating in potting process of epoxides
Matoušová, Klára ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
The bachelor's thesis is dealing with the defects in epoxy resin flooded transformer devices. Since these can be damaged severely in terms of quality by numerous forces, the main focus is dedicated to the impact of moisture. The thesis describes the manufacturing technology including the methods applied and materials used. It further encompasses the composition of epoxy resin and the mechanisms used for their hardening processes. Additionally, the description of the moisture, the impact of adverse forces and the method of their elimination using drying is presented. In the experimental part of the paper, a moisture of the banding materials was measured. On the basis of the results acquired, the paper reaches a conclusion on the ideal time frame of drying, the sufficiency of materials in terms of drying and in two cases two substitutes for contemporary uneasily dryable samples were considered.
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The overview and the evaluation of the technical specifications of transparent materials for the production of composite wood panels
Holub, Jan ; Böhm, Martin (advisor) ; Arnetová, Karolína (referee)
Work includes: general introduction to the components of the wood-based panels with a transparent layer, the history of their production. It includes requirements for individual components of composite wood panels and requirements for wood and other wood-based materials, which serve as reinforcement. Also mentions claims potting material, which serves as a matrix.
It includes a description of the technology of wood-based panels with a transparent layer. This paper introduces the most commonly used material serving as a matrix, their distinctive characteristics essential for the production of composite plates. Compares parameters resins based on polyester, polyurethane and epoxy resins and analyzes the choice of a suitable material for producing a composite board based on user requirements. Part of this work is to design materials for the manufacture of composite board with controlled light distribution.
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Draft controlled modular source 6,3kA / 5VAC for warming trials and tests breakers
Zolich, Ladislav ; Dostál, Lukáš (referee) ; Dohnal, Petr (advisor)
The main object of this thesis is to design a toroidical transfomer on the given parameters. Project is focused on learning about principles of transformers, it’s designing and mainly on designing the given transformer. Designing contains material selection of the core of the transformer, its size, then calculating magnetic flux, no-load current, cross-section of conductor and calculating no-load losses and joule losses. The next part is designing the mechanical parts of transformer, its terminal plate, base and cooling system. Thesis is also mainly focused on designing the form for potting the transformer in epoxy resins. In the end is measurement and form of powering the transformer.
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Potting Compounds for Power Electronics
Štajner, David ; Červinka, Dalibor (referee) ; Vašíček, Adam (advisor)
Potting compounds are often used in electrotechnics to protect the electronics from the adverse effects, improves its insulating properties and helps to improve the heat transfer from the embedded devices in the surroundings. Embedding electronics into encapsulants extend the field of application. Such electronics can then be used in wet, dusty, corrosive or otherwise harsh environments.
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