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Aging and possibilities of its removal
Kolena, Robert ; Šlais, Miroslav (referee) ; Podaný, Kamil (advisor)
Thesis elaborates on current study of aging issues and describes its development caused by interstitial nitrogen and carbon atoms. It also points out how properties of materials are influenced. There are several removal options. The first one is heat treatment consisting of recovery and recrystallization annealing, the second one is binding of nitrogen atoms to chemical elements with higher affinity and third one is rolling with realization of small plastic deformation. Overall assessment and practical examples are also added.
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Influence of aging on sandwich materials properties
Smékal, Aleš ; Löffelmann, František (referee) ; Klement, Josef (advisor)
The first part of the master’s thesis deals with sandwich materials. Starting with composition of parts which the sandwich panel is made of. The thesis continues with loading distribution and testing of entire sandwich panel. The impact of environment is considered as well. The second part is its goal – determine degradation of the properties of sandwich panels with metal sheets and core after 15 years aging in the common atmosphere and aging in moistheat and salt environment by experiment.
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The effect of production parameters on the plasticity of structural steel
Brabec, Martin ; Podaný, Kamil (referee) ; Peterková, Eva (advisor)
The master thesis deals with the influence of heat treatment and storage time on microstructure and mechanical properties of 26MnB5 steel, which is used in the production of tubular components in the quenched and tempered state. The objective was to increase the plasticity of the steel by the definition of new process parameters of the induction heat treatment line. New tempering diagrams of 26MnB5 steel for two various speeds of the heat treatment line were established and used to determine new tempering temperature and speed of the heat treatment line. Observation of the influence of storage time on mechanical properties of the steel did not reveal that it is liable to ageing.
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WETTABILITY OF PCB SURFACE FINISHES
Minář, Jan ; Jana, Toulová (referee) ; Starý, Jiří (advisor)
This bachelor’s thesis with measuring of wetting characteristics by the wetting balance method for samples of different surface finishes from the firm Gatema. It deals with influence of the isothermal aging and reflow processes on wetting characteristics of surface finishes ENIG, HAL and immersion tin. The influence of intermetallic layer on the overall wettability is studied in case of the surface finish of immersion tin. Also deals with the wettability of the nickel layer, after stripped off gold, in case of the surface finish of ENIG.
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Senior citizens home Sokolnice
Vávra, Vít ; Šindlar, Jiljí (referee) ; Marek, Jiří (advisor)
The area of the former barracks lies near Sokolnice falling into the periphery of Brno. It is a picturesque village that has a rich history. The barracks are located on a hill called Stará hora, there are several cadastral areas. Near the building, we can find a radar that manages the nearby Brno airport, or the Peace Mound built on the Prateck Hill, soldiers fall to remembrance. The design principle was based on the given operation and its related functions. Dining room, rehabilitation, barber, pedicure, buffet and, last but not least, a multifunctional hall with a small library. The destruction of the unnecessary transformer station and the replenishment of the mass was a logical solution to the situation. It is an assembled reinforced concrete frame 8x8m. Inside the half-block we find a terrace with a pool, which is trying to create a specific microclimate and humidify the surroundings. The pool also serves as a retention tank and the house effectively manages rainwater. Within the lifetime, because of the corrosion of reinforced concrete and the unclear condition of the structure, I designed the exterior cladding to demolish and build a new cladding, a brick made of ceramic blocks. The house is designed in a minimalist spirit and cooperates with the greenery in its surroundings. Especially in long-distance views of integration into the landscape, this greenery is valued. The spirit of place in heavy air bears a strange whiff of dragging death that, when thinking about the history of a place, froze and freezes ... so perhaps while resting before the last journey ... that house discourages and breathes a little life into dying ...
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Kinetics of hydrophobic organic compounds uptake in the earthworm Eisenia andrei in soils with different content of organic carbon
Šmídová, Klára ; Zlámalová Gargošová, Helena (referee) ; Čáslavský, Josef (advisor)
This thesis is concerned with the fate of hydrophobic organic pollutants (HOCs) in soil. The theoretical part summarizes the current knowledge about bioavailability, factors influencing the bioavailability and methods for its measurement. Attention is paid to the organic carbon content, which is considered to be one of the key factors and to the influence of microorganisms that can degrade or interact with the substances, thus changing their bioavailable ratio. The practical part of the thesis uses bioaccumulation test with earthworm Eisenia andrei for evaluating the uptake kinetics HOCs in three soils with different organic carbon content. Soils were laboratory contaminated with mixtures of selected HOCs (phenanthrene, pyrene, lindane, p,p'-DDT and PCB 153) and the concentrations of substances in these soils were followed for 217 days. Subsequently, bioaccumulation test was conducted; earthworms were exposed from one to twenty-one days. The collected data were used to model uptake kinetics curves for individual substances. Peak-shaped bioaccumulation were found for pyrene, for lindane a steady-state concentration during exposure was observed, whereas for p,p'-DDT and PCB 153 growing concentrations after twenty days of exposure were detected. The reason for the different behavior of the substances was probably their diverse sorption on the organic material, which together with the different speed of elimination influenced final concentration in earthworms. Phenanthrene was not detected in some samples and therefore the modeling of uptake kinetics was not possible.
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Elimination of degradation processes of metallic thin films
Danovič, Jakub ; Šubarda, Jiří (referee) ; Šimonová, Lucie (advisor)
This work deals with issues of thin films, their behaviour in different enviroments and protection of theese films against unwanted degradation processes. Metal thin films are made by special physical or chemical methods in the presence of vacuum. Deposition is performed on properly cleaned substrate made of different materials, for example glass, ceramics or another metal. Theese films degrades under the influence of moisture, heat and other. There are several types of films on different bases made to prevent thin films against degradation.
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FET aging model
Novosád, Jiří ; Legát, Pavel (referee) ; Semiconductor, Aleš Litschmann, ON (advisor)
This work deals with problems aging of unipolar transistors. In theoretical parts are described the mechanisms which causing aging unipolar transistors and way leading to the restriction the change of parameters in time. The measurement and data evaluation was built on theoretical knowledge. The model of aging FET is a result of this works; it is creating extraction of data from measured data. Finally, the degradation constants are evaluation from this data. This FET aging model is easy to use in simulators of electronics circuits including aging simulations (e.g. ELDO).
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Analysis of mechanical properties of plastic samples produced by 3D printing technology
Jiroušek, Jan ; Joska, Zdeněk (referee) ; Sedlák, Josef (advisor)
The master's thesis deals with the determination of mechanical properties of materials used for 3D printing (PLA, PETG, ABS, ASA). The theoretical part contains characteristics of polymer materials and describes testing of mechanical properties and additive technologies. In the experimental part, the standardized samples produced by the technology Fused Filament Fabrication were analysed using mechanical tests (tensile test and hardness test). Some of the examples were exposed to the selected factors of degradation. Selected parameters from mechanical testing (tensile strength, modulus of elasticity in tension, elongation and Shore hardness) were statistically processed. The conclusion of the thesis evaluates the impact of the factors of degradation on particular materials and compares them subsequently.
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Images of femininity in women's art products
NOVOTNÁ, Silvie
The bachelor thesis deals with the representation of images of femininity in its various aspects in artefacts of women. The Theoretical part focuses on theoretical background and relies mainly on feminist approaches in psychotherapy and art therapy. The Theoretical part establishes the themes that are pursued in the research part in the respondents' artworks. The analysis of the artefacts is carried out in accordance with the procedures of the projective-interventionist approach in art therapy with a substantial involvement of feminist perspectives in the interpretative procedures.
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