Angl. resumé

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Submitted paper deals with the current condition of electrical insulating substances used in electrical engineering, including the requirements on their electric and mechanical qualities. Another part of this paper constitutes a set of samples of epoxy resins and through and application of appropriate diagnostical methods the characterization of their attributes in the wide temperature range.

The goal of the thesis is to try and test the functionality of fire protection coatings, which are intended to protect against the direct effects of fire. This is the protection of furniture materials that are used predominantly in areas where fire can occur (restaurants, bars, public interiors), but also in the home near heat-generating devices. The purpose of surface protection is to prevent the spread of fire, to protect the flammable underlying material and to reduce the amount of smoke generated. The tests will be carried out according to ČSN EN 13501-1. The subject of the thesis is also to compare the mutual interaction of the substrate material and the paint composition with respect to the overall fire resistance and subsequently to evaluate the lowest weight loss during the flame action. The rest of the tests will deal with the determination of paints parameters such as adhesion to the surface, resistance to temperature changes, etc.

The thesis deals with the pouring of epoxy materials over LED strips. The research part contains an introduction to photometry and summarizes the types of potting compounds along with their characteristics. The practical part delves into the effect different amount of pigment has on the photometric properties. This is assessed based on verified measurements performed with the help of a goniophotometer on samples with different amounts of pigment, which were created using an integration sphere. Furthermore, a brightness analysis and a long-term outdoor test were performed.

The aim of this thesis was to determine the effect of row spacing on sorghum yields and dry matter. The trial was established on 29 May 2015 on land belonging to the Agricultural Cooperative Milevsko, which is situated in the corn-growing area. The trial compared four varieties of sorghum, namely Aristos, Goliath, KWS Freya and KWS Sole. The varieties were sown in different row spacings, namely 75 cm, 60 cm, 45 cm a 30 cm. The samples taken on three dates were analysed for dry matter content. Each variety showed a gradual increase in the dry matter content. During the harvest on 5 October 2015 the varieties KWS Freya and KWS Sole reached an optimal value of the dry matter when planted in all spacings. All varieties produced the highest average yield of green matter when planted in rows spaced 60 cm apart. The variety Aristos produced the highest average yield of green matter. The KWS Sole variety reached the lowest average yield of green matter when planted in rows 76 cm apart. All varieties with 60 cm row spacings, except for KWS Sole, produced the highest average yield of dry matter. The highest average yield of dry matter was reached by Aristos and the lowest by KWS Sole. The results of the one-year trial did not prove a direct connection of the effect of row spacing on dry matter. The effect of row spacing on green and dry matter yield was proved. The optimum row spacing seems to be 60 cm.

This diploma thesis deals with the adhesion influence of anticorrosion coatings that are applied on the surface of a metallic material. The first part of the work focuses on corrosion, its division and commonly found types. The following part is aimed at protecting against such corrosion damage, including all types of anticorrosion protection. A very important part of this work is surface preparation before application of paints, which is discussed in the third part, where are described the individual methods of preparation. The fourth part deals with the anchorage profile defined and described in detail, and mentioned is also the closely related surface roughness. The subsequent anchorage profile assessment is performed by the comparison method, which consists of roughness sample ranges and follows the part defining the coating compounds, their classification, labelling as well as the colour scheme, up to their properties and methods of application on the material surface. One of the most important parts of the work is the experimental section focused on adhesion testing of the selected coatings in four types of anchorage profile using the pull-off test. The last part is an analysis of the application of knowledge about the coating system adhesion in the field of expert engineering and proficiency.

The diploma thesis "Different microbial activity in the rhizosphere of grasses Festuca ovina and Calamagrostis epigejos" deals with the issue of climate change and eutrophication and their impact on the stability of rare habitats, specifically dry acidophilous grasslands in the Podyjí national park. The aim of the thesis is to study and collect the available sources about the issue of the interaction of soil microorganisms and plant roots in exceptional and protected dry grassland ecosystems, which are colonized by aggressive expansion of Calamagrostis epigejos, thereby compromising their integrity and stability. This issue is still not fully understood. Review of literature in the thesis describes the explanation of the most significant part of the issue - the nutrient cycling in ecosystems, C: N ratio, the role of microorganisms in the soil, and the importance of microbial processes in the rhizosphere and in grassland ecosystems generally. In the experimental part the hypothesis - that drought stress and eutrophication causes changes in the plant - microorganisms - soil system, which result in destabilization of the system, by an increase in leakage of nitrate and ammonium ions from the soil, and in changes in the quantity and quality of underground and aboveground biomass of Festuca ovina -- was confirmed.