|
|
Retaining Walls
Pospíšil, Jan ; Boštík, Jiří (referee) ; Glisníková, Věra (advisor)
The objective of thesis is to create a comprehensive overwiew of the most commonly used retaining walls in the Czech Republic and to characterize their properties, method of assessment, advantages, disadvantages or causes of failures. Based on these findings will be designed selected type of retaining wall in Rebešovice.
|
|
|
Preparation and characterization of perovskite solar cells
Juřík, Karel ; Salyk, Ota (referee) ; Pospíšil, Jan (advisor)
This work deals with the perovskite photovoltaic cells. The first part summarises the basic information about this technology and shows the most important milestones in its development. Following part includes the parameters required to characterise the electric properties of a photovoltaic cell and the assessment of its quality. The experimental part of this thesis aims to describe the influence of the annealing time of the perovskite active layer on the final efficiency of created solar cells. The best results were determined to be achieved with the annealing time of 90 minutes.
|
|
|
Housing+
Mikulová, Marie ; Pospíšil, Jan (referee) ; Sládeček, Svatopluk (advisor)
The core focus of this project is the solution of the land planning in the area of Tomkovo náměstí in Brno near the Velký městský okruh. It deals with the impact of the circuit’s dual carriageway on the surrounding environment and offers how to integrate this transport structure into the newly built area as well as into the original urban area. The solution includes a composition of objects designed either in a form of permanent living space or a hostel, all with the addition of an outside marketplace.
|
|
|
Passivation of the active layer in perovskite solar cells with inverted architecture
Babincová, Kristina ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
The topic of this work is the passivation of the active layer of perovskite solar cells with an inverted structure. The work is divided into theoretical and experimental part. The theoretical part describes in particular the passivation and modification of the perovskite layer as well as the characteristic properties of perovskite, including structure and stability. The experimental part deals with the preparation of photovoltaic cells with an inverted structure. For the characterization of photovoltaic cells, reference samples were prepared and their active layer was modified by plasma. The most used deposition technique for the preparation of layers was the spin coating method. From the performed experiments it can be concluded that the preparation of samples and their subsequent modification under laboratory conditions does not lead to the improvement of the final parameters of photovoltaic conversion. By transferring the sample preparation and passivation of the active layer to an inert atmosphere, it was possible to produce cells with higher efficiencies (compared to the reference sample), around 10 %. Another advantage of this plasma treatment of the active layer is that it also improves the stability of the prepared structures, which even after a few days in air show almost 80 % of the original efficiency.
|
|
|
Study of the dielectric properties of perovskite crystals
Mlčkovová, Hana ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
The presented diploma thesis deals with the preparation of perovskite single crystals by inverse thermal crystallization and subsequent study of the basic properties of these hybrid organic-inorganic materials that can be used in various optoelectronic (photodetectors, transistors, lasers, LEDs) or photovoltaic applications. Their behavior in the electric field was studied by impedance spectroscopy. Impedance and capacitance-voltage (C-V) characteristics (frequency dependences) were measured in the dark and in the light. From the impedance dependences for measurements at 0 V voltage in the dark, the equivalent circuit was modeled and its parameters and dielectric constant were determined. From the C-V dependence, Mott-Schottky analysis determined the parameters – "flat-band" potential U_"fb" and charge carrier density N_"C-V" , the parameter – the so-called Warburg coefficient was found, which together with the parameter N_"C-V" was used to calculate the diffusion coefficient D.
|
|
|
Virtualized web application for receiving data from sensors
Kharytonov, Oleh ; Fujdiak, Radek (referee) ; Pospíšil, Jan (advisor)
At the beginning of the theoretical part, the bachelor thesis focuses on LPWAN or Low-Power Wide-Area Network technology. Systems that are characterized by low power consumption and wide coverage. Their key features are discussed. Subsequently, attention is paid to the LoRaWAN\texttrademark\ standard,. Initially, LoRa\textsuperscript{\tiny\textregistered} modulation is discussed - the modulation techniques used and the advantages over competitors. The next step discusses LoRaWAN\texttrademark\, - architecture, types of end devices and security. Virtualization - uses in today's world, discusses types of virtualization and its benefits. The practical part introduces the commissioning of open-source LoRaWAN\texttrademark\, ChirpStack server, gateway, endpoint registration and activation. Attention is paid to an application programmed using Flask for device management and data reception. The principle of operation and commissioning of the virtualized web application is explained. Finally, the results and possible ways to improve the application are described.
|
|
|
Recognition of security issues in LPWA type networks
Shestopalov, Artur ; Pospíšil, Jan (referee) ; Pospíšil, Ondřej (advisor)
The bachelor’s thesis deals with the issue of recognizing security incidents in LPWA (LowPower Wide Area) networks. Thesis contains information about the most used LPWA technologies, examines their security architecture and possible threats. Part of the work is a detailed description of LoRaWAN protocols, including architecture, possible attacks, distinguishing security architecture in the new and old versions. Work contains implementation of two security incident scenarios and their subsequent detection: jamming and gateway disconnection. As part of the detection, was created a web application that is able to detect real-time security incidents based on the average value of RSSI (Received Signal Strength Indicator) and the expected time of message transmission.
|
|
|
Security assessment of standards of IEEE 802.11 family
Řihánek, Tobiáš ; Pospíšil, Jan (referee) ; Pokorný, Jiří (advisor)
The aim of this work was to analyze the issue of security testing of the IEEE 802.11 protocols. The thesis includes a theoretical analysis of these protocols and a list of their vulnerabilities. Software used for testing the security was showcased. A utility was created to help with the testing. Finally, the thesis looks at the use of SDR as a way of testing security.
|
|
|
Architecture of home
Očadlíková, Veronika ; Pospíšil, Jan (referee) ; Mléčka, Jan (advisor)
The thesis is based on monitoring how one represents, creating an environment, how one completes it, or how the human environment is created. When we ask ourselves what our home means for us, we knew we could give it the shape of space. We could describe it as a place where we like to be. Some questions arise. If there is any idea of living at home, if it is as personal, how does each of us perceive home in his intimacy as well? How did it become the architecture itself? The goal of the work is to translate the understanding of the home through a specific situation. I choose a village in Slovakia, Čechynce, which has more than 1000 inhabitants. The architectural design itself does not adapt to the creation of a home as a house. He wants to point out that the home is not in an isolated system of walls, but in an ability of distence and in a chance to return again.
|
|
|
Perovskite solar cells
Poláková, Simona ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
The bachelor´s thesis deals with the study of perovskite solar cells. The theoretical part of this work is devoted to the stability of the perovskite layer and perovskite solar cells, especially chemical and thermal stability are discussed. Furthermore, deposition methods of perovskite active layer were described in more detail. The experimental part deals with the influence of the dropping of the diethyl ether solution during the deposition of the active layer (at different time intervals) on the final efficiency of solar energy conversion, with the preparation of the final perovskite solar cells and with the characterization of the basic electrical properties of the prepared structures.
|
guest ::
RSS feed.