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Fire as an alternative way of the landscape management
Maximov, Fedor ; Novák, Jan (advisor) ; Adámek, Martin (referee)
Prescribed burning is a method that has been used since prehistoric times to keep unforested areas. In pastures, fire was used to remove dead biomass, return nutrients to the soil and improve forage quality, as well as to convert forests fields to a shifting agriculture. The abandonment of burning in the last century has led to an accumulation of plant biomass in the landscape. This, combined with global warming, is now creating the threat of dangerous fires. In 2022, controlled burning was allowed in the Czech Republic as a way of managing habitats that are at risk of becoming woodland without proper management. Rare heliophilous plant and animal species are tied to them. It would therefore be advisable to reintroduce this management method, together with monitoring and control of its effects on species and communities. The aim of this backelor thesis is to summarise the existing knowledge about prescribed burning in Europe. It also describes how controlled burning affects the dynamics of dry grasslands and heathlands. The main focus is on attributes of controlled burning that can be used to maintain selected habitats. Keywords: fire, vegetation, landscape management, succession
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Impact of warming on soil organic carbon
Štecová, Michaela ; Vindušková, Olga (advisor) ; Jílková, Veronika (referee)
Climate change is the main cause of rising global temperatures around the world. Carbon sequestration in terrestrial ecosystems is considered one of the main tools for climate change mitigation, but current estimates of sequestration potential do not include the impacts of future climate change. The aim of this thesis is to summarize our current knowledge on the response of soil organic carbon to warming, alone as well as in combination with other drivers of climate change. A complementary aim is to compare the different methods used to study the impact of warming on soiIncreased temperature causes significant losses of soil carbon, but no consistent effect has been observed in combination with other aspects of climate change. Research suggests that carbon losses depend on the stability of soil fractions, with warming leading to greater decreases in particulate organic matter (POM). The combination of warming with rising CO2 concentration has led to an overall increase in soil carbon, although losses have been observed in combination with drought. When studying the effects of warming on soil carbon stocks, selecting the appropriate method is crucial. Active methods offer precise control but are more expensive and can impact soil biota, whereas passive methods are cheaper but require more time....
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Fire of batteries in electric vehicles
Blažek, Štěpán James ; Sitek, Tomáš (referee) ; Preisler, Lukáš (advisor)
This bachelor thesis deals with the causes and formation of fires in electric vehicle batteries. The first part summarizes the theory related to types of batteries, used materials, and reviews the phenomenon known as Thermal runaway. The second part of the thesis describes the burning of electric vehicles, providing basic categorization of fire occurrence in electric vehicles and the phenomena accompanying them. The statistical comparison of the current and future development of the number of fires in electrically powered vehicles in the Czech Republic compared to conventional combustion engines, data analysis, and recommendations are summarized in the final part of the bachelor thesis. From the given statistics, it is evident that an electric vehicle is less likely to catch fire, however, it is acompanied by the release of hazardous gases, creating a significant challange in terms of fire extinguishing.
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The Methodology for Testing the Bond Between FRP Reinforcement and Concrete Under the Influence of High Temperatures and Fire
Zlámalová, Pavlína ; Zlámal, Martin ; Čairović, Đorđe ; Lagiň, Juraj ; Vašátko, David ; Štěpánek, Petr
The determination and understanding of the bond strength between FRP reinforcement and concrete, which ensures the mutual interaction of these materials, are indispensable for the proper, safe, and reliable design of concrete structures with internal reinforcement. This characteristic also serves as a fundamental parameter for designing the anchorage length of the reinforcement.
While it is one of the fundamental characteristics, there is no domestic or international standards defining the procedure for testing and determining the influence of high temperatures and fire on the bond strength between FRP reinforcement and concrete.
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Buckling Length of Steel Columns in Frame Structures Stressed by Fire
Červenka, Roman
Fire resistance is crucial for load-bearing structures. However, current rules in structural Eurocodes may not cover all fire design situations. In EN 1993-1-2, fire design rules exist only for braced steel frames, treating each floor as a separate fire section. Unbraced frames lack specific fire design rules and use regular temperature design buckling lengths. This article presents an analysis of the behaviour of columns in braced and unbraced frames and compares it with the procedures of some other authors.
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Evaluation of environmental load by polybrominated diphenyl ethers
Roček, Richard ; Stoupalová, Michaela (referee) ; Vávrová, Milada (advisor)
The target of my diploma thesis is evaluation of soil load by polybrominated diphenylethers. This is the soils, which were affected by fire and comparsion with load by soils, which were not affected by fire. In teoretical part available informations about BDE from various sources are processed. Target of practical part is find the optimal method for determination BDE, verification of her yield a determination of reals samples with using this method. In the end this thesis contains measured results, its interpetation in tables, graphes and evaluation of load by individual congeners. Key is comparsion load of soils, which were affected and which were not affected by fire. BDE are released during the fire and we can decide that soils which were caused by fire should be contaminated more, than soils, which were not caused by fire.
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ASSESSMENT OF REINFORCED CONCRETE STRUCTURES EXPOSED TO ELEVATED TEMPERATURES
Rozsypalová, Iva ; Kolář,, Karel (referee) ; Vítek,, Jan (referee) ; Daněk, Petr (advisor)
Doctoral thesis is focused on the assessment of concrete structures after fire exposure and extends the knowledge in view of the main aims of the research defined in the objectives of his work. Thanks to the performed fire tests of full-scale concrete specimens, material characteristics corresponding to actual fire load have been assessed for different temperature levels. Resulting from presented research, main steps of assessment procedure have been recommended for both destructive and non-destructive tests of concrete after exposure to fire. Furthermore, behaviour of FRP reinforcement at elevated temperatures have been investigated. Aiming to determine the effects of fire exposure on reinforced concrete structures, experimental program have been defined and performed, including concrete beams reinforced with either steel, or composite reinforcement with glass or carbon fibres and subjected to experimentally simulated fire load. After cooling, bending test have been executed. Above mentioned experimental program was further complemented by extensive numerical analysis. Finally, presented work provides guidelines regarding further investigations required in this field of research.
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Volumetric Efects Accelerated on GPU
Kubovčík, Tomáš ; Tóth, Michal (referee) ; Starka, Tomáš (advisor)
This thesis deals with simulation and rendering of fluid based volumetric effects, especially effect of fire and smoke. Computations are accelerated on graphics card using modern graphics API with motivation to achieve realistic visual results as well as physically correct calculations. Implemented volumetric effects are distributed as dynamic library which allows addition of these effects to existing applications.
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