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Effect of selected abiotic stress factors on yield formation parameters of winter wheat genotypes
Hlaváčová, Marcela
This dissertation thesis is a compilation of four scientific papers based on experiments with pot-grown winter wheat plants. The responses of winter wheat to different lengths of drought and heat stress treatments, applied at growth phases crucial for grain formation, both from the perspective of final yield formation and photosynthetic parameters, were analyzed. Growth chambers (heat and drought stress) and phenotyping platform (drought stress; phenotyping experiment) were used to set up these stress conditions. The first aim was to assess the sensitivity of yield formation parameters to short-term heat stress at anthesis. The second aim was to assess the sensitivity of yield formation parameters to drought stress during the transition from the vegetative stage to the generative stage. The third aim was to assess the sensitivity of yield formation parameters and photosynthetic characteristics to combined short-term heat and drought stress at stem elongation, anthesis, and grain filling stages. The final aim was to assess the sensitivity of photosynthetic characteristics to combined medium-term heat and drought stress at the anthesis stage. The results showed that short-term (3 and 7 days) heat (32, 35, 38 °C, and compared to a control temperature of 26 °C) or interactive effects of heat and drought stress at stem elongation, anthesis, and grain filling stages generally led to minor reductions in yield formation parameters, whereas significant affects on photosynthetic parameters were observed (with the lowest impacts on photosynthetic parameters at anthesis). It indicated that plants were capable of quickly recovering their photosynthetic processes; thus, yield formation parameters could be compensated. Drought stress during the transition from the vegetative stage to the generative stage of development resulted in significant declines in yield formation parameters. The photosynthetic responses to medium-term (7 and 14 days) combined heat and drought stress were genotype-specific in their magnitudes and closely associated with changes in stomatal conductance.
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Modeling of temperature phenomena in Li-Ion cells
Grézl, Vojtěch ; Sedlařík, Marek (referee) ; Vyroubal, Petr (advisor)
This thesis deals with the issue of heat generation in Li-ion batteries, which can have a negative impact on the battery properties and functionality. The thesis can be divided into two main parts. The theoretical part focuses on the theoretical description of Li-ion batteries, heat generation, thermal effects, ideal operating temperatures, modelling of these situations, the occurrence of different types of abuse and the consequences that can arise from incorrect or inadequate thermal management. The practical part focuses on the analysis of the results from the discharge temperature measurements for different load values C and the initiation of the effect known as thermal runaway for 18650 Li-ion cell, and then on how to simulate these behavior in the Ansys Fluent.
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Energy supply of the complex Technicka 2
Buráň, Petr ; Lisý, Martin (referee) ; Pospíšil, Jiří (advisor)
The theme of this master thesis is „Energy supply to the site Technická 2“. This thesis is divided into several parts. First we will get in touch with concept of combined heat and power and also with principle of photovoltaic electricity production. We will continue with description of site before and after reconstruction. Then we will follow with analyze the effect of reconstruction on energy consumption. In the end we will make some suggestions for using the local source of heat and electricity in Faculty of mechanical engineering, Brno university of technology. All suggestions will be analyzed from energy and economic point of view.
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Heat storage in solar thermal systems
Mokriš, Lukáš ; Hejčík, Jiří (referee) ; Charvát, Pavel (advisor)
In this bachelor’s thesis are described methods of heat storage in solar thermal systems. Solar energy is retrieved in form of solar radiation, that is processed and stored in the form of sensible heat of solid materials and liquids, as heat of fusion of some material or as chemical heat, which is created during reversible chemical reactions.
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Analyses of the Compressed Air Energy Storage proces in Ansys Fluent system
Hájková, Věra ; Šabacká, Pavla (referee) ; Maxa, Jiří (advisor)
This bachelor thesis discusses different types of energy storage in the introduction. It describes the different technologies, their functions, advantages and disadvantages. It compares them on the basis of the ESOI ratio, which is the ratio of energy stored on invested. The main type of energy storage covered in the term paper is compressed air energy storage. The thesis describes the principle of a method of energy storage as well the companies and projects that are working on or using this technology. Furthermore, the issue of heat energy loss during air compression is outlined, which leads to a significant reduction in efficiency. The last part of the thesis is a practical part, which uses a model example to show the temperature and pressure evolution during the pumping of air into the storage tank.
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Temperature Profile in Reflow Soldering and Influence of Different PCBś and ComponentsThermal Capacities
Procházka, Martin ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis mainly deals with the prediction of temperature on the components and the PCB during reflow soldering. The theoretical part describes the particular solder reflow process, types of heat transfer and temperature profiles. The practical part is divided into forecasting temperatures if the conveyor is stopped and the temperature predictions when the conveyor is in motion. In both parts of the measured temperature is compared with the predicted temperatures, which show the success rate of prediction. The last part of this work is part of the simulation, which helps in proper understanding of the issues discussed.
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Study of Thermal Properties of Materials
Štefková, Pavla ; Pavlík, Zbyšek (referee) ; Matiašovský, Peter (referee) ; Zmeškal, Oldřich (advisor)
The doctoral thesis deals with study of thermal properties of materials. Behavior of homogeneous matters at different temperatures is well described in theory and experimentally verified. Overall effect of all components of mixture and other influences related with material creation affect behaviour and properties of heterogeneous matters. For study of thermal properties can be used transient method of measurement which provide a picture about overall influence of all components of mixture on studied heterogeneous material and among others enable determination of thermophysical properties of whole macroscopic system in observed temperature range. Properties of solid matters, thin foil and liquids can be measured by means of pulse and step-wise transient method which is used for experimental activity in the thesis. It is contact measurement method and its principle is based on small quantity of heat generating inside the specimen and temperature response measuring. Theoretical part of thesis is focused on creation of method for determination of thermophysical parameters. The base is differential equation of the heat conduction. Its solution is temperature function. Three methods of evaluation are described mathematically. They start from general relations designed for study of fractal structure physical properties (maximum of function method, differential method and multi-parametric non-linear regression method).
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Workstation with termo camera
Zeman, Martin ; Horák, Karel (referee) ; Richter, Miloslav (advisor)
This thesis contains an overview of physical principles concerning thermography and infra-red sensing, and a specification of a measuring instrument in a measurement system. Next, there are some particular examples of IR sensing applications. In the second part there is a thermal camera market research including individual manufacturers and models with their attributes and prices. There is a closer view of the thermal camera used for this thesis (Guide EasIR-4). In the end of the thesis there are some drafts of computer vision subject tasks (or practices), including workplace designs and solutions, and three task suggestions for bachelor or diploma theses including solution verifications.
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Aircraft air-conditioning systems
Lednický, Ondřej ; Horák, Marek (referee) ; Třetina, Karel (advisor)
The bachelor thesis is focused on the aircraft air-conditioning systems, their functions and basic tasks needed for a safe and comfortable flight. The thesis is divided into several chapters: the first one deals with the most important factors influencing human health. Next chapter is focused on a description of the assurance of main components which are composing the aircraft air-conditioning system. Final chapter of the thesis deals with oxygen systems, which are essential for the survivor of the passengers in the case of an accident.
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