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Optoelectronic application of perovskite nanoparticles
Ambro, Filip ; Zdražil,, Lukáš (referee) ; Pospíšil, Jan (advisor)
This bachelor thesis deals with the utilization of perovskite nanoparticles in optoelectronics. The thesis is composed of three main parts. The first part focuses on the theoretical properties of perovskite materials, with an emphasis on their structure and properties influencing their electrical and optical behavior. The second part describes the procedure for preparing solutions of these nanoparticles, their subsequent characterization, the preparation of thin layers, and the subsequent characterization of the optical, electrical, and dielectric properties of these layers. The final part is dedicated to presenting the results of the work and discussion.
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Aerosol particles morphology
Odehnalová Šamanová, Jaroslava ; Linda, Jakub (referee) ; Pospíšil, Jiří (advisor)
This thesis focuses on airborne Particulate Matter (PM), the floating dust that surrounds human beings every day, its composition, morphology, size and concentrations in the air. The first, introductory part of the thesis, describes the basic concepts, properties and health risks associated with aerosol particles, and relevant legislation. The second, experimental part of the thesis, describes the instruments used, followed by the results of emission sampling and immission sampling, and a comparison of measured concentrations in three selected locations: in a village, in a city, and in a family house. The third part, the analysis, investigates freely available air pollution immission monitoring data, including long-term data, data from occasional events such as New Year’s fireworks, or sporadic occurrences such as a forest fire in České Švýcarsko national park. The conclusion summarises the achieved results, and the appendix consists of a catalouge of dust particles, in which all emission samplings carried out within the experimental part of the thesis are listed.
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Proposal for the Extension of the Functionality of Electronic Shelf Labels for the Improvement of Communication with Customers
Petýrková, Pavlína ; Pospíšil, Jan (referee) ; Chlebovský, Vít (advisor)
The topic of this thesis is a proposal to expand the functionalities of electronic shelf labels to enhance communication with customers. The thesis is divided into three parts – theoretical, analytical, and proposal. The theoretical part is based on professional literature and is crucial to a deeper understanding of the issue. It also serves as a basis for the analytical part. In its introduction the company DATART is presented. The analytical part then deals with answering partial research questions interviews, questionnaire survey and observation. Based on the results of the analysis, the proposal part develops proposals focusing on specific measures and strategies that will meet the defined objectives.
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Using of Perovskite Nanoparticles in Biochemistry
Srncová, Melanie ; Tumová, Šárka (referee) ; Pospíšil, Jan (advisor)
This bachelor's thesis examines study of the properties of lead halide perovskite nanoparticles and their use in biochemistry. The synthesis of two types of perovskite nanoparticles MAPbBr3 and MAPbCl3 was performed using the LARP method. During the synthesis was observed the influence of the mixing length of the precursors on the properties of these solutions, which were characterized using UV-VIS spectrophotometry, fluorescence spectrometry and dynamic light scattering. A discussion of the obtained results was carried out along with a discussion of the suitability of using these perovskite nanoparticles in biochemistry due to the toxicity of the lead that these nanoparticles contain.
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Dispersion of particulate matter pollution from electric vehicles in urban areas using CFD
Lipka, Jakub ; Pospíšil, Jiří (referee) ; Linda, Jakub (advisor)
There is an opinion across the society, that electric vehicles (EV) are emission-free alternative to vehicles using internal combustion engines (ICEV). This is not true. Although electric vehicles do not produce emissions connected to internal combustion, they still produce non-combustion emissions that are emitted into surrounding air. Non-combustion emissions in question are brake wear particles (BWP), tire wear particles (TWP) and road wear particles (RWP). These emissions, due to EV’s greater mass, tend to be higher compared to ICEVs. Therefore, in this thesis, model of dispersion of non-combustion emissions generated by EVs was created using CFD consisting of two models – airflow model around EV and particle dispersion model. It was found that those emissions are captured and distributed by airflow, mainly thanks to vortices generated in the wake zone behind the vehicle. Those particles can be suspended up to 1,9 m into the air and up to 2,5 m laterally away from the vehicle. Thanks to that there is a risk of pedestrian inhaling air with high concentration of those particles in places near roads like pavements.
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Model of electric charge transport in perovskites and their precursors
Raška, Vilém ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
Thesis focuses on analysis and determination of basic electric properties of perovskite materials. Thesis includes theoretical section which discusses electric properties and charge transport in solid materials. In the experimental section several chloride and boride perovskite material samples are used for measurement of VA characteristics and Impedance Spectroscopy. Then based on acquired data multiple models are created which are then used to determine required properties and state distribution of samples.
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Evaluation of real PV system operation
Macák, Vít ; Gregorovičová, Eva (referee) ; Pospíšil, Jiří (advisor)
This bachelor thesis covers photovoltaic systems, their various configurations and main components. It analyses a specific installation on a single-family house, evaluating the operational data and the economic return of the system. The thesis also provides recommendations for future operations and system expansion options.
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Multi-stage impactor
Kojecký, Dalibor ; Sitek, Tomáš (referee) ; Pospíšil, Jiří (advisor)
This master’s thesis is focused on the problem of laboratory capture of fine particles by the impaction method. The introductory chapter is devoted to the investigation of fine particles in air and the impact of air pollution on humans and the environment. The second chapter intro-duces the history of impaction devices, describes the principles of the cascade impactor, and explains the theory behind fine particle capture by changing the direction of the airflow carrying the particles and their capture when they hit a solid wall. In the practical part of the thesis, a computational procedure is developed using the Python programming language for a custom design of a multi-stage impactor. The parameters obtained from the developed computational software are compared with those of a commercial impactor available at the faculty of the school. According to the developed computational procedure, a custom multi-stage impactor is designed for particle separation in the range of PM0.5 to PM0.1.
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Mobile island photovoltaic system
Zelenka, Petr ; Baláš, Marek (referee) ; Pospíšil, Jiří (advisor)
The mobile island photovoltaic system is a technology designed for electricity generation in locations without traditional electrical grid infrastructure. This compact portable device combines solar panels with batteries and other components, such as charge controllers and inverters. Its mobile nature allows deployment in remote locations (isolated houses, military bases, mountain cottages, campsites) and in emergency situations. The first part of the bachelor's thesis focuses on the issue of generating electrical energy through photovoltaic conversion and its storage in batteries, while the experimental part focuses on measuring the characteristics of photovoltaic panels with different inclinations and shading. It also models the utilization of solar energy under various sunlight conditions. The thesis provides an overall perspective on the importance of mobile island photovoltaic systems and their potential in the field of renewable energy and sustainable development.
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Study of multilayer perovskite structures properties
Gabzdyl, Adam ; Kratochvíl, Matouš (referee) ; Pospíšil, Jan (advisor)
The bachelor thesis focuses on the optical, electrical and dielectric properties of perovskites and their multilayer structures for use in optoelectronic applications. Samples of lead MAPbI3 and lead-free Cs3Bi2I9 perovskite in a photovoltaic cell of FTO/SnO2/perovskite/spiro-OMeTAD/Au structure were prepared and studied. The optoelectrical properties were determined by direct current measurement of current-voltage characteristics and the dielectric properties were determined by impedance spectroscopy. It was determined that with this photovoltaic cell structure, lead perovskites are a more suitable material for optoelectronic applications than lead-free perovskites because they exhibit many times higher solar energy conversion efficiency and possess more favorable electron processes.
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