National Repository of Grey Literature 576 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Conversion of a gasoline engine to burn hydrogen
Prchal, David ; Böhm, Michael (referee) ; Drápal, Lubomír (advisor)
The master’s thesis deals with the hydrogen combustion in reciprocating internal combustion engines, a topic that is becoming more important with the planned transition to low-emission mobility. basic physical properties of hydrogen, which are compared with conventional hydrocarbon fuels. Differences in terms of mixture formation, heat release rate, heat transfer, performance, emissions and other operating parameters are described. Based on the information found, a theoretical proposal for the conversion of the 1.5 TSI evo2 gasoline engine to hydrogen combustion is made, with emphasis on achieving sufficient power, a suitable torque curve, low emissions and the lowest possible conversion costs. Data from other hydrogen spark ignition engines are analysed and few different combustion models for hydrogen are developed. A simplified 1D model of the baseline engine is created and modified for hydrogen applications. A new intake cam profile is designed for the high engine load, the approximate size of the required turbocharger is recommended, intake air cooling requirements are determined and minor structural modifications to the cylinder head are proposed. The result meets the stated objectives and demonstrates that modern spark ignition internal combustion engines can be used in combination with hydrogen as a low-emission fuel with low conversion costs.
Spatio-temporal distribution of atmospheric aerosol in urban and rural environment
Bendl, Jan
Air quality in Europe remains a significant environmental concern, affecting the health and quality of life of its population. While stationary network ambient air quality monitoring allows for the observation of main trends, it is not fully representative of personal exposure of citizens due to high spatio-temporal variability of atmospheric aerosol. Therefore, highly time-and- space resolved measurements with state-of-the-art instruments and methods are needed to observe the aerosol variability, dynamics, identify hot-spots, and pollution sources, which are necessary for successful targeted mitigation measures. This thesis addresses this gap focusing on the characterization of spatio-temporal distribution of atmospheric aerosol in inhabited environments. Novel mobile measurement systems were developed and employed to investigate diverse environments, including rural, urban and suburban area. Aerosol source-apportionment were conducted, and the toxicological effects associated with these environments were also investigated. A novel mobile measurement system was developed for personal exposure measurements and pollution mapping in urban and rural environments. The system was used to measure air quality in the Munich subway, revealing high aerosol dynamics with significantly higher concentrations of...
Effect of electromagnetic compatibility on the operation of automotive LED drivers
Vinklerová, Viktorie ; Šteffan, Pavel (referee) ; Levek, Vladimír (advisor)
The diploma thesis deals with electromagnetic compatibility, its bonds, measuring devices and interference sensors. Furthermore, the thesis includes a discussion of nearfield probes, standards CISPR25 and TEM chamber methods. It describes two integrated circuits NCV78964 and NCV78514 LED drivers from onsemi and their modules. The aim of the work is to design the measurements, then to implement and evaluate them. Finally, to optimize the operating parameters of the drivers with respect to both EMC and driver functionality.
Implementace biopotravin a lokálních potravin do společného stravování
Various efforts to reduce greenhouse gas emissions are increasingly being seen around the world. Agriculture and the food sector contribute to greenhouse gas emissions, and therefore it is necessary to introduce measures aimed at their mitigation. Organic food and short supply chains are associated with lower environmen-tal impacts, and school canteens offer great scope for mitigating climate change just by implementing these measures. An often-mentioned problem is the higher financial costs of buying organic or locally produced food. This work shows that, in the case of choosing the right ingredients and involving the right logistics, the fi-nancial costs for one portion do not have to exceed 1.5 % of the price increase. The work also shows that the implementation of organic food is not necessarily as key to mitigating climate change as the implementation of local food. To apply these results to other cases, research focused on specific canteens and their possibilities for the supply of local food is necessary.
Vyhodnocení emisí amoniaku z chovu drůbeže ve vybraném zemědělském podniku
HES, Adam
This bachelor's thesis focuses on the assessment of ammonia emissions from agricultural operations and their potential impact on the environment and human health. The aim of the work is to analyze the factors affecting ammonia emissions and propose possible measures to reduce them. To achieve this goal, measurements of ammonia emissions were carried out using specialized sensors located in different places of the farm. At the same time, information was collected on the procedures and technologies used in animal husbandry and fertilizer storage. The analyzes carried out showed that the main sources of ammonia emissions in the analyzed agricultural company MTD Ústrašice are the breeding of farm animals and the application of fertilizers to the fields. We identified factors such as the type and size of animal husbandry, storage methods, and fertilizer application techniques that affect ammonia emission rates. Based on our findings, we propose the implementation of measures aimed at reducing ammonia emissions, such as optimizing fertilizer storage technologies, modifying procedures and using alternative animal husbandry methods. These measures should contribute to the protection of the environment and human health in the given agricultural enterprise.
The development of energetics in the Czech Republic during the following years
Musil, Miloš ; Kracík, Petr (referee) ; Toman, Filip (advisor)
This thesis analyses the current Czech energy sector. It describes its current state and outlines possible scenarios of its development in future years in the context of the energy transformation. The thesis seeks to analyse the current situation of the energy sector in the country, assess its strengths and weaknesses and identify opportunities and threats for future development. The thesis describes the different parts of the Czech energy sector, such as the electricity, gas, heating and oil industries, including production sources, consumption and emissions. Most emphasis is given to the electricity sector. The capacities and potentials of the different sectors are analysed alongside the possible future scenarios outlined. Part of the thesis is also focused on describing and explaining the composition and construction of electricity and gas prices in the Czech Republic. Emphasis is also placed on placing the Czech energy sector in the broader context of the energy sectors of European countries and includes various scenarios for the development of the electricity sector in Europe. In the context of the current geopolitical situation in Europe and the modernisation and transformation of this sector, it is necessary to build new energy sources.
Operation of electric vehicles, hybrid vehicles and vehicles with an internal combustion engine
Herzog, Radim ; Píštěk, Václav (referee) ; Kučera, Ondřej (advisor)
This bachelor's thesis deals with the comparison of different propulsion concepts and their consumption, efficiency, and amount of emissions produced during operation. Although electric vehicles do not produce any local emissions, it is necessary to consider that emissions are generated during the production of electricity in power plants. The main part of the thesis introduces the functional principles of individual propulsion systems. Furthermore, it describes the formation of exhaust gas emissions in combustion engines and outlines their limits. Subsequently, the amount of emissions produced by a power plant for the operation of a specific example of an electric vehicle and a hybrid vehicle is calculated. Finally, a comparison of emissions production from representative examples of each propulsion system is illustrated.
Predicting spark-ignition engine emissions
Jirout, Petr ; Böhm, Michael (referee) ; Štětina, Josef (advisor)
This diploma thesis deals with the possibility of predicting emissions of SI engines. The aim was to create an algorithm for predicting unburned hydrocarbons and carbon monoxide, based on ECU signals. The algorithm is based on practical experiments with SI engines. In the summary, the issues and the possible use of the created algorithm following the incorporation of EU7 are outlined.
Alternative Fuels for CI-engines
Matoušek, Martin ; Řehák, Kamil (referee) ; Dundálek, Radim (advisor)
The topic of this bachelor thesis is alternative fuels applicable in diesel engines. First, a brief introduction to the diesel engine is given, then the individual alternative fuels are described. The most important findings about these fuels are summarized and a comparison with diesel fuel is made. Finally, each fuel is evaluated in terms of its advantages, disadvantages and applicability in practice.
Diesel Particulate Filters and Various Types of their Regeneration
Štěpánek, Josef ; Svída, David (referee) ; Dundálek, Radim (advisor)
This work deals about creation particulate matter and their impact on health. It focused on diesel particulate filters and various types of their regeneration. Differences of various designs and producers of diesel particulate filter are introduced in this work.

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