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Hydrogen vs. electricity - comparison of energy performance of EV powertrains
Šándor, Kristián ; Mišík, Ondrej (referee) ; Fišer, Jan (advisor)
The topic of emission reduction and the increase in the share of energy produced from renewable sources remains actual and highly discussed in 2021. It was the major reason why I chose to compose this bachelor’s thesis, in which I aim to critically evaluate and compare the energy performance of an electrical vehicle and a hydrogen vehicle. The theoretical part of the thesis outlines the aforementioned drivetrains as well as the plug-in hybrid drivetrain. The practical part of the thesis focuses on calculations of the energy performance of the drivetrains for the year 2021 with a rational estimate for 2050. The methods of electricity and hydrogen production are crucial for energy performance evaluation. Data shows that electric cars operated in countries with a high share of energy produced from renewable sources are the least energetically demanding. On the other hand, if the energy production depends predominantly on fossil fuels, it is more efficient to operate a hydrogen vehicle. Calculations show that when considering the indirect emissions during the operation as well as the energy performance, the plug-in hybrid vehicles are the least efficient. The difference in efficiency between electric and hydrogen vehicles varies depending on the mode of energy production of that specific country. The conclusion of this thesis also discusses advantages, disadvantages and technological challenges concerning the aforementioned drivetrains.
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Face masks and respirators as protection against viruses and bacteria
Varga, Michal ; Mišík, Ondrej (referee) ; Lízal, František (advisor)
Pandemic caused by virus SARS-CoV-2 brought high attention to face masks and raised some questions about their filtration efficiency and performance affecting parameters such as high humidity, long term usage, fit factor, or possible decontamination methods for usage prolonging. In this thesis, mechanisms of SARS-CoV-2 transmission and structure and materials of face masks are firstly discussed. Then mechanisms of particle deposition on filter fibers are described. Subsequently standards of surgical masks, cloth masks and respirators are described and compared, with detail on carbon dioxide concentration under respirator. Nanoparticles and their possible effects on enhancing face mask parameters are briefly characterized. Then filtration efficiency and affecting parameters are evaluated. And finally possible decontamination methods for face masks reusability are summarized.
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A complex mechanistic lung model
Chumchal, Ondřej ; Mišík, Ondrej (referee) ; Jedelský, Jan (advisor)
This bachelor thesis looks at review of published airway models, with purpose of finding best avaliable solution for extension of current BUT model, reaching 7th generation of branching. The main purpose of the thesis is expanding model further into lower generations. Secondly, it deals with possibilities of getting more realistic results by coming with influence of temperature and humidity. Two main approaches were chosen, which shall be further more explored and adopted into use in BUT model, those are glass bead and rod model. In order to make model as realistic as possible, dimensionless characteristics such as Reynolds number and ratio of inner surface and volume of each generation were calculated to match those in real human lungs. The thesis concerns expansion down to 12th generation. Further calculation of deposition and flow parametres should be done, in order to verify mentioned approach.
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Inhalers and nebulizers for medical use: their principles, reliability, and operating parameters
Mišík, Ondrej ; Tuhovčák, Ján (referee) ; Lízal, František (advisor)
An issue of inhalation therapy is a complex topic, actively discussed in last decades, and its progress in various scientific fields is more than required. First part of this thesis brings a theoretical introduction into principles of aerosol therapy and into the requirements resulting from them. Commonly available technologies of inhalers and nebulisers for medical usage, parameters that determinate their effectivity are briefly described. Usage mistakes influencing the effectivity of inhalation are discussed, as well. Second part deals with experimental measurements of aerosol that selected inhalers generate. It also describes difficulties connected with the methods of these measurements, with sampling and following analyses. Gained results are compared with an available literature.
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Kinds of transportation and impact on the enviroment
Trojánek, Zdeněk ; Mišík, Ondrej (referee) ; Prinz, František (advisor)
The bachelor thesis deals with transport and its impact on our surroundings, but also on our health. The main part of the work presents the characteristics of the mode of transport in terms of emissions and noise production. The resulting emissions are analyzed and the individual components are described in terms of their impact on nature and human health. The next part deals with possible ways to reduce emissions and noise and the different modes of transport are compared with each other.
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Inhalers and nebulizers for medical use
Mišík, Ondrej ; Tuhovčák, Ján (referee) ; Lízal, František (advisor)
This work provides a research study of inhalation systems, their history, development and current forms. It clarifies the principles of common inhalation technology and focuses on the reasons of their research and their innovations. It focuses on the impact of particle size on inhalation therapy. The experimental part of this work deals with the measurement of particle size distributions administered from selected inhalers and determination of respiratory fractions.
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Application of the Life Cycle Assessment (LCA) method to passenger cars
Šándor, Kristián ; Mišík, Ondrej (referee) ; Fišer, Jan (advisor)
The electrification of personal transport is an intensely discussed and relevant topic in 2023. The motivation behind this master thesis was to compare the lifetime energy consumption of vehicles equipped with internal combustion engines, battery-powered electric systems, and fuel cells. The theoretical part of this master thesis includes the introduction and explanation of the method by which a product lifecycle is assessed, known as LCA. The dissertation includes a chapter detailing the main components of automobiles, followed by a chapter which has calculations the energy consumption of production, operation, and recycling or destruction of the automobiles. The outcome of the theoretical part shows that the lifecycle of a battery-powered electric car is the least energetically costly, followed by internal combustion cars, and fuel cell cars being the most energy costly. The practical part of this master thesis involved a physical decomposition of a vehicle with an internal combustion engine with the aim of obtaining the material composition of its components and applying the LCA method on the vehicle Skoda Octavia III. The thesis sparks future research and eco-friendly alternatives in personal transportation.
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The harmfulness of the hookah and the factors that affect it
Žabka, Miroslav ; Lízal, František (referee) ; Mišík, Ondrej (advisor)
In the recent period teahouses have been gaining a lot of traction and with them comes more and more consumers of hookahs. A lot of people perceive hookah smoking as less harmful to your body than cigarette smoking. The first part of this bachelor’s thesis consists of literature retrieval that deals with particles arising from hookah consumption and their deposition in the lungs, what is their influence on the human body and subsequently measurement methods that are used in practice. The aim of this work was to find out which factors influence the emitting particles that are produced by hookah consumption. The practical part deals with the construction of a measuring line for the aerosol that is produced when smoking a hookah. Subsequently, the influence of water, coconut and high-flammable coals on the resulting aerosol was investigated.
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Respirator filtration efficiency
Tolnaj, Tomáš ; Mišík, Ondrej (referee) ; Bělka, Miloslav (advisor)
Aerosols are everywhere around us and pose an increasing risk to human health. That is why aerosols and their filtration are the subject of several researches. This bachelor thesis focuses on established standards for respirator testing according to the European standard and factors influencing their filtration efficiency. The research also includes a description of the theoretical background of aerosols, the physical principles of deposition, a detailed description of respirators. The thesis contains an experimental part, which consists of designing, assembling and setting up the experimental rig with subsequent measurement of the filtration efficiency, pressure loss and evaluation of the measured results.
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Hydrogen vs. electricity - comparison of energy performance of EV powertrains
Šándor, Kristián ; Mišík, Ondrej (referee) ; Fišer, Jan (advisor)
The topic of emission reduction and the increase in the share of energy produced from renewable sources remains actual and highly discussed in 2021. It was the major reason why I chose to compose this bachelor’s thesis, in which I aim to critically evaluate and compare the energy performance of an electrical vehicle and a hydrogen vehicle. The theoretical part of the thesis outlines the aforementioned drivetrains as well as the plug-in hybrid drivetrain. The practical part of the thesis focuses on calculations of the energy performance of the drivetrains for the year 2021 with a rational estimate for 2050. The methods of electricity and hydrogen production are crucial for energy performance evaluation. Data shows that electric cars operated in countries with a high share of energy produced from renewable sources are the least energetically demanding. On the other hand, if the energy production depends predominantly on fossil fuels, it is more efficient to operate a hydrogen vehicle. Calculations show that when considering the indirect emissions during the operation as well as the energy performance, the plug-in hybrid vehicles are the least efficient. The difference in efficiency between electric and hydrogen vehicles varies depending on the mode of energy production of that specific country. The conclusion of this thesis also discusses advantages, disadvantages and technological challenges concerning the aforementioned drivetrains.
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