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Theoretical Investigation of Low-dimensional Magnetic Materials
Li, Shuo ; Grajciar, Lukáš (advisor) ; Frauenheim, Thomas (referee) ; Jelínek, Pavel (referee)
Low-dimensional (D) materials, such as graphene, transition metal dichalcogenides and chalcogenide nanowires, are attractive for spintronics and valleytronics due to their unique physical and chemical properties resulting from low dimensionality. Emerging concepts of spintronics devices will greatly benefit from using 1D and 2D materials, which opens up new ways to manipulate spin. A majority of 1D and 2D materials is non-magnetic, thus their applications in spintronics are limited. The exploration, design and synthesis of new 1D and 2D materials with intrinsic magnetism and high spin-polarization remains a challenge. In addition, the valley polarization and spin-valley coupling properties of 2D materials have attracted great attention for valleytronics, which not only manipulates the extra degree of freedom of electrons in the momentum space of crystals but also proposes a new way to store the information. The computational investigation of magnetic and electronic properties of low-dimensional materials is the subject of this thesis. We have systematically investigated geometric, electronic, magnetic and valleytronic properties of several 2D and 1D materials by using the density functional theory. These investigations not only theoretically show rich and adjustable magnetic properties of...
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Design of the hobby CNC milling machine
Hrala, Adam ; Tůma, Jiří (referee) ; Štěpánek, Vojtěch (advisor)
The focus of the bachelor's thesis concerns the design of a CNC model milling machine. It includes a representation of the kinematics of individual types, operating systems for these machines, hazard analysis and market research. In the second part there is a design of the overall device from the point of view of the drive and guidance of individual axes, the electronics used and a design of the machine structure supplemented by a drawing of the assembled device.
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Redesign of the construction and control algorithm for an unstable robot with a spherical base
Novák, Vlastimil ; Najman, Jan (referee) ; Spáčil, Tomáš (advisor)
This bachelor thesis deals with the redesign of an unstable robot with spherical base, also known as Ballbot. The aim of the work is to analyze the existing structural elements of the robot, available sensors, control and power electronics and identify functional deficiencies. Subsequently, design a solution and implement it in order to eliminate all found deficiencies. Part of the work is testing a revised version of the robot, which, among other things, consists of checking the functionality of individual sensors and checking the comunication between sensors and microcontroller. Emphasis is placed on determining the real accuracy of newly used sensors depending on the settings used and ambient conditions.
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Design of Robot end effector with automatic tool exchange
Jirges, Radek ; Chalupa, Jan (referee) ; Krejčí, Petr (advisor)
The goal of this thesis was to design an end effector for a small robot for testing of devices with a touchscreen. The effector has to communicate with the robot via serial interface and provide feedback about used downforce. Another requirement was possibility of automatic tool change. Measuring of downforce, signal processing, and communication with robot ensures custom electronics based on STM32 microprocessor and piezoresistive sensor. The mechanism of tool change was inspired by the system used with industrial robots but customized for this application. The result of this thesis is a functional prototype of a stylus for devices with a touchscreen which provides feedback about the downforce on display and possibility of automatic tool change. The main benefit of this solution is the possibility of changing the tool for the one with one or more styluses for testing gesture-based interface what is indispensable in these days.
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Design of a complex HIL simulator of car boot door
Obrtáč, Tomáš ; Krejčí, Petr (referee) ; Spáčil, Tomáš (advisor)
This thesis covers the development of complex HIL simulator for the fifth car door. The beginning of the thesis is dedicated to theoretical research in the area of In-the-Loop testing. Practical part describes development of HIL simulator complemented by power electronics part. A simulation environment Matlab/Simulink was used for control design and analysis. Before the beginning of the work was measured signal part of control unit and specific signal sequences were identified. The control was applied on sbRIO device from National Instruments company with the implementation of a model on FPGA. Specific requirements for sensing speed and generation of communication signals lead to creation of unique hardware for application needs. The result of the thesis is complex HIL simulator with intuitive GUI and possibility of simulations a wide range of DC motors.
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Smart Home
Pitra, Ondřej ; Jašková, Jana (referee) ; Kazda, Tomáš (referee) ; Šedrlová, Magdalena (advisor)
Cílem této bakalářské práce je seznámit čtenáře a popsat mu základní principy, charakteristiky a použití mého vlastního projektu s názvem Chytrá domácnost. V této práci se budu zabývat dosavadním stavem mého projektu a dále popíši budoucí plány pro moji Chytrou domácnost. Taktéž představím a porovnám systémy chytrých domů od firem, které se touto technologií zabývají několik let.
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Tests of Semiconductor Detectors in Prague Laboratory
Krásny, Peter ; Kodyš, Peter (advisor) ; Carli, Ina (referee)
This thesis is focused on the usage of silicon semiconductor detectors in ATLAS experiment and automation of safe cooling and heating processes needed during the tests performed on detectors at a given tem- perature. The tests take place in the freezer environment with the place of interest where the detector is to be placed required to stay dry throughout the entire test. This is secured by monitoring the temperature and rela- tive humidity of the environment using Interlock device with sensors and by automatic calculation of the dew point temperature without any supply of nitrogen commonly used in other set ups of the tests. Both cooling and heating processes are being prepared to be fully automatized, reducing the amount of manual handling required to minimum which helps to maintain the conditions and safe run of the test. 1
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Beta Source Tests of Semiconductor Detectors ITk for ATLAS Upgrade
Kovanda, Ondřej ; Kodyš, Peter (advisor) ; Scheirich, Daniel (referee)
Beta Source Tests of Semiconductor Detectors ITk for ATLAS Upgrade Abstract: The ATLAS experiment is due to undergo a major upgrade for the High Luminosity phase of the LHC operation. In particular, the current tracking system (ID) will be replaced by full-silicon ITk. IPNP laboratories are involved in R&D of SCT detector modules for ITk. Low-temperature β-source tests of the R0 FR 5 module prototype were the main focus of this thesis. After testing the cooling cycle, 11 threshold scans were performed on two ABC130 chips, yielding the median collected charge ranging between 2.9 ± 0.2 fC and 3.1 ± 0.2 fC for chip #6 at SNR from 16.0 ± 1.0 at 24 ◦ C to 22.7 ± 1.5 at −15 ◦ C. No trend with temperature was observed outside the error bars. The results are in accordance with previous similar measurements. Question of fitting the median collected charge in various units was adressed and equivalence of the fits was determined. The ability of IPNP laboratories to perform low-temperature β-source tests was proven.
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