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Fluctuations in the groundwater level in the montane peat bog Rokytka
Lencová, Kateřina ; Šobr, Miroslav (advisor) ; Doležal, Tomáš (referee)
Peatbogs are globally widespread ecosystems that have a major influence on the hydrological conditions of watersheds. Of particular importance are mountain highlands, which are characterized by their occurrence in the source areas of streams. Despite the indisputable importance of the montane peatbogs in terms of runoff conditions, their influence has not yet been conclusively clarified. Montane peatbogs are a particularly important topic for the Šumava region, where they represent a fundamental element of the landscape. The study site is therefore situated in one of the Šumava's spring areas - the Rokytka watershed. As part of this thesis, the issue of the hydrological function of the monitored peatbog has been viewed mainly through the differences in the fluctuation of the groundwater level in different parts of the peatbog. At the same time, the influence of the precipitation on the change in the groundwater level in the peatbogs and on the runoff response of the Rokytka brook has been monitored. Precipitation is the only source of water for the highlands and its influence is therefore crucial. Although several previous studies have focused on the influence of this highland on the runoff conditions of the Rokytka brook, groundwater levels from manually measured probes have not yet been analysed....
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High temperature corrosion behaviour of nicr-based coatings applied by twin wire arc spray technology
Lencová, K. ; Vostřák, M. ; Naďová, J. ; Lukáč, František ; Mušálek, Radek
High temperature corrosion is a serious problem related to the combustion of heavy oils with high vanadium contents. Protective overlay coatings are used to allow functioning of engineering components under extreme conditions and provide corrosion resistance to extend the component life. This article is concerned with the high temperature corrosion behaviour of two protective NiCr-based coatings and bare structural steel 1.4959 (W.nr.) in a molten salt environment of 40% Na2SO4 and 60% V2O5 at 750 °C under cyclic condition. NiCr and NiCrMoNbTa coating was deposited on steel 1.4903 (W.nr.) by Twin wire arc spray technology (TWAS). To establish the kinetics of corrosion, the thermogravimetric technique was used. The X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) techniques were used to analyse the corrosion products and determine the corrosion mechanism. The hot corrosion resistance of both coatings was better than bare steel samples. The NiCrMoNbTa coating showed better corrosion behaviour than the NiCr coating. However, also the NiCr coating provides sufficient protection to the substrate material.
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High temperature corrosion studies of HVOF sprayed coatings in molten sulphate salts environment
Lencová, K. ; Česánek, Z. ; Houdková, Š. ; Lukáč, František ; Mušálek, Radek
The generally applied requirements on lowering of emission production in the field of power industry have led, among others, into the application of low-emission combustion process of coal fired power plants. Besides the emissions reduction, this process has led to an increase of boilers parts corrosion degradation due to the reducing atmosphere in low-emission boilers, responsible for sulphide corrosion and molten salt attack. In such environment, the protection of the exposed surfaces gains importance. Among others, the thermal spraying technology can offer a suitable way of surface corrosion protection. In the present work, the high temperature corrosion behaviour of CoCrAlYTaCSi and Cr3C2-25%NiCr High Pressure/High Velocity Oxygen Fuel (HP/HVOF) sprayed coatings is evaluated and compared to the behaviour of bare structural steel (SPT360) substrate. The specimens were exposed to a molten salt environment, i. e., 12% Na2SO4 + 82% Fe2(SO4)3 at 690 °C under cyclic condition, simulating the working environment in low-emission boilers of coal-fired power plants. The thermogravimetric method was used to establish the kinetics of corrosion. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) techniques were used to analyse the corrosion products and determine the corrosion mechanism. The thermogravimetric measurement shows high oxidation rate of SPT360 steel. Cr3C2-25%NiCr coating provides slightly better performance compared to CoCrAlYTaCSi coating. Based on the obtained results, both coatings were found to have higher corrosion resistance than the SPT360 steel substrate, offering a sufficient surface protection in a given environment.
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Influence of rock glaciers on hydrological regime
Lencová, Kateřina ; Šobr, Miroslav (advisor) ; Falátková, Kristýna (referee)
Within this work, a literary research was performed on the topic of rock glaciers and their influence on river runoff. Rock glacier are features typical for high-mountain periglacial environment. Through the accumulation of part of the flowing glacial water, they significantly affect the timing and quantity of watershed discharge. In addition, stone glaciers preserve significant volumes of water in the form of buried ice, the gradual melting of which regulates river runoff, especially in the dry seasons. A physical- geographical characteristics of the Ala Archa river basin was performed and supplemented by a more detailed climatological characteristic of the study area based on the own processing of meteorological data from the Adygine meteorological station. The purpose of this work was to assess the impact of rock glaciers in the basin of eight selected rivers, which drain the Kyrgyz and Kungej Alatau, on their hydrological regime. It was found that the presence of rock glaciers in the monitored basins affects the runoff regime of these rivers, especially by reducing the differences between their June and July runoffs. Key words: rock glacier, hydrological regime, Tien Shan
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Manifestations of Behavioural Accounting in Agriculture
LENCOVÁ, Kristýna
The bachelor thesis is focused on the analysis and identification of the manifestations of behavioral accounting inside an agricultural establishment. The enterprise "Agro Liblice, s. r. o." was chosen as the object of this thesis. The behavioral approach will be analyzed in the area of subsidies that the enterprise is a receiver of. The thesis deals with the process of obtaining subsidies, as well as the relationship between the enterprise and the subsidiess and the accounting of investment subsidies.
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