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Nerovnoměrná tepelná úprava dřeva - vlastnosti
Daněk, Václav
Present study analyses the impact of Cross – section uneven thermal modification of wood caused by hot press at 200 °C. The beech wood was examined at radial and tangential direction. The resulting samples were chemically analysed by spectrophotometry to determine the penetration depth of the thermal modification. Also, was examined dimensional stability during soaking at water for 15 days. In the first part is a review of literature on the description of the heat treatment and common using methods in practice. Further, the material properties of the beech wood and the possibilities of using this material were examined. Measured data were statistically analysed, the results were discussed and compared with the literature.
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Vliv tepelné modifikace na vybrané vlastnosti bukového dřeva tlakově impregnovaného přírodními oleji
Daněk, Václav
Present study aims to analyze thermal modification of beech wood (Fagus sylvatica L.) press-impregnated by natural oil and its influence on physical and mechanical properties of wood. Beech wood was press-impregnated by hemp oil (O 1000) and thermally modified at 200°C for 3 hours. Influence of certain treatment (i.e. oil impregnation, thermal modification, combination) was experimentally investigated using physical and mechanical tests. Color changes (CIELab system), dimensional stability and bending strength were experimentally measured and results compared with reference group. Results of given work was further discussed and compared with literature. Results shows increase of dimensional stability about 18% after thermal modification (TM) and 22% for oil impregnated and thermally modified wood (OL+TM). Mechanical performance (bending strength) decreased about 5,2% after thermal modification as a results of degradation of wood cell wall. On the other hand, strength increase about 9% for wood impregnated by oils. Combined processed provide results within similar range as reference. Results should be further discussed and parameters of process (temperature levels) as well as influence of various oils parameters (drying, semi-drying, nondrying) tested in future.
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Possibilities of commercial use of social networks
Daněk, Václav ; Žamberský, Martin (advisor) ; Bruckner, Tomáš (referee)
Main objective of this thesis is to analyze social networks as a means of advertising. Thesis takes down congruity of presentations of firms and companies but also individuals across the social networks. I devoted the greatest attention to networks Facebook, Twitter, YouTube and Myspace as the most popular and the most important in Czech Republic. Other social networks I am comparing with Facebook as the most widespread worldwide. Sub-chapters are focused to analyze specific social networks -- especially those which are most used in present time. Thesis also analyzes appropriateness of using advertisement on particular social networks and its efficiency. Then I tried to determine the best social network to speak to potential customers. The future is the last topic of my thesis. I attempted to outline the direction of social networks, not only in the marketing perspective. Other points which I attempted to outline are fall of present network or rise of new networks. The antithesis to the future is short exposition about history of the most popular networks and their origin.
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