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Interaction between TiAl melt and coated oxide refractories
Dočekalová, Kateřina ; Dlouhý, Antonín ; Zemčík, L. ; Fiala, J.
The present study focuses on reactions between ceramic crucibles and molten TiAl intermetallics. Coating strategies are investigated that exhibit a potential in slowing down the decomposition of the crucible wall. Uncoated crucibles (system TiAl melt - Al2O3 crucible) and crucibles with the coat (system TiAl melt - CaO coat - Al2O3 crucible) were used in melting and casting experiments. The reference state of the coated crucible before the melting trial was also investigated. Results of the SEM, EDAX and X-ray diffraction analysis contributed to the identification of the reaction zone and its chemical composition. The melt contamination with oxide inclusions results from the erosion process in which individual components of the melt diffuse along grain boundaries of the refractory and activate chemical reactions that decompose the crucible wall. Assessment of thermodynamic parameters associated with the chemical reactions helped in identifying the nature of the erosion process.
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Reaction of selected varieties of winter oilseed rape (Brassica napus) on the application of fungicides
Vojík, Jan ; Bečka, David (advisor) ; Michal, Michal (referee)
Oilseed rape i sone of the most important crops in the world. I tis the most important oil crop in Czech Republic. I the last 50 years it had undergone large change in breedeng. Ratio of grown hybrids at present tops the open pollinated lines ( planning for harvest in 2016 saw 88% hybrids and only 12% of lines). There are quite important differences between varieties in tolerance to fungal diseases and not only to them. There are first varieties marketed with gene of pot shatter tolerance and others. The pressure of fungal diseases grows due to growing planting area of the rape.
Trials with oil seed rape were established in the growing season 2014/15 on four varieties and two locations. We tested following hybrids: Arsenal (Limagrain), DK Exstorm (Monsanto), Jumper (Bayer), SY Cassidy (Syngenta). The locations were in the district Jičín farm AGRO Slatiny a.s., and in the district Kolín farm ZD Křečhoř a.s.. On each location were planted two trial variants 1) without fungicide application 2) with the application of fungicides. On the location Slatiny were applied three fungicides (Toprex, Paroli, Propulse), on the location Křečhoř also three fungicides (Toprex, Magnello, Amistar XTRA).
The aim of the bachelor study was to test growth yield and qualitative parameters of the varieties together with observation of fungal diseases and their influence on yield and oil content. We were testing the infestation of following diseases Phoma lingam, Sclerotinia sclerotiorum, Verticilium dahlie Botrytis cinerea.
Hybrid DK Exstorm (195cm) was the tallest variety on both locations followed by hybrid Arsenal (193,5 cm). By number of branches was the best ranked variety hybrid Arsenal, the lowest was SY Cassidy. On fungicide treated variants grew number of pods per m2 by average 6% on both locations. Average yield vas slightly higher in location Křečhoř in both variants, treated (70kg) and untreated (50 kg). On both locations was visible difference between treated and untreated variants. Yield increase was in average 5,4% (200kg/ha). Varieties with best reaction to fungicide treatment were DK Exstorm (Monsanto) and Jumper (Bayer). Fungicide application influenced also crop height, number of branches and pods per m2.
Following conclusions are made in the bachelor study:
- Fungicide application increased yield in average by 5,4% (i.e.200 t/ha) and improwed the health of the crop.
- DK Exstorm and Jumper were varieties with the best reaction on the fungicide treatmentArsenal (4,37 t/ha) was the best yileding variety on both locations followed by hybrid Jumper (4,27 t/ha).
- Arsenal is the recomended variety for both locations Křečhoř and Slatiny
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Proposal for a stove fire
Štelcl, Otakar ; Skála, Zdeněk (referee) ; Baláš, Marek (advisor)
Abstract The diploma thesis is divided into five main parts. First part deals with wood as a firing in term of its composition, emissions of carbon dioxide and its properties. The second part describes the calculation of a stove fire, especially stoichiometry of firing, temperature of uncooled flame and area of combustion chamber. The third part focuses on the proposal for a stove fire in connection with comparative criteria of the fireplace, shape of the combustion chamber and the tertiary air jet. The fifth part describes a manufacturing of the stove fire in the work-room at VUT Brno. The major part of the diploma work pays attention to the measuring of stove fire parameters for the effectivity calculation, measuring section of combustion gas and measurement evaluation with stove fire constructional modifications
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Steam boiler burning fytomass waste
Plot, Rostislav ; Skála, Zdeněk (advisor)
This thesis deals with the calculation of the boiler on stillage. Nowadays, when there's fossil fuels are just biomass seems adequate compensation. The great advantage of biomass boilers is a small amount of emissions, especially the greenhouse gas CO2. Of a given fuel composition is made thermal calculation and dimensioning of heat transfer surfaces of steam boilers. The resulting calculation must follow the parameters of steam at the outlet from the boiler.
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Power Line Communication Simulator in Network Simulator-3
Kolář, Jan ; Fujdiak, Radek (referee) ; Mlýnek, Petr (advisor)
This thesis deals with the powerline communication focusing on the simulations of channel transfer functions. The introduction summarizes basic information about PLC followed by the analysis of the available PLC Software simulator (implemented in NS-3) and the analysis of implemented noises and interferences and its extensions. One chapter is devoted to possibilities of link capacity calculation. Within the thesis, various methods of calculation of primary parameters of transmission line were implemented and the simulator was compared with other freely available simulators. Subsequently, simulations were carried out focused on channel transfer functions in different topologies, on the impedance changes of branch, on the lengths of branch, and changes in the direct path between communicating nodes.
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Design of up-to-date laundry premise model
Marek, Tomáš ; Máša, Vítězslav (referee) ; Pavlas, Martin (advisor)
Scope of this thesis is the design and evaluation of a laundry processing facility. Main goal was to prepare, design and evaluate part of the technological layout for a modern, high-volume laundry processing facility. The focus was on the main apparatuses, main process flow, as well as the supporting process flow, related equipment and key components of field instrumentation with standard description. 3D facility model was prepared on the basis of proposed technological layout, using the SolidWorks software package. This model shows placement of all key equipment and components as well as physical disposition of connection tubing within the building. Final part of work reviews proposed options of process parameters measurement. Such measurements which are important for the evaluation of energy consumption of considered laundry processing. We discuss both pros and cons of evaluated and selected suitable measurement devices, tools and procedures. Constructed 3D model of piping lines shows placing and dimensions of selected measurement devices.
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Optimisation of experimental parameters for double-pulse LIBS
Roščák, Michal ; Novotný, Karel (referee) ; Kaiser, Jozef (advisor)
Diploma thesis presents the description of laser induced breakdown spectroscopy (LIBS) analytical method. The possibility to decrease LIBS detection limits using double pulse LIBS (DP-LIBS) is also detailed. Properties of laser induced plasma (LIP) are discussed. Thesis describes the optimisation process of DP-LIBS setup at laser spectroscopy laboratory of Faculty of Mechanical Engineering, Brno University of Technology. Optimisation was carried out for detection of chrome in steel with respect to detection limits and ablation crater size. Optimised DP-LIBS setup is appropriate for mapping chrome distribution in steel samples.
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Comparison of quantitative LIBS analysis of steel standards utilizing single-pulse and double-pulse LIBS
Pořízka, Pavel ; Hrdlička, Aleš (referee) ; Kaiser, Jozef (advisor)
In this diploma thesis the differences between single pulse and double pulse laser induced breakdown spectroscopy (LIBS) methods are discussed. The time evolution of laser induced plasma (LIP) parameters, such electron density, plasma temperature, density of ions and atoms is shown. Selected methods for evaluation of plasma parameters (Boltzmann equation, Saha-Boltzmann equation etc.) are also stated. The theoretical bases of local thermodynamic equilibrium (LTE), which is necessary condition for using of previously stated methods for computation of plasma parameters, are discussed. Diploma thesis also contains the description of each component of our LIBS experimental set up and the way of their optimization. Presented theoretical advantages of DP LIBS method are demonstrated on results of experimental measurements of steel standards.
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