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Proposal control system motorcycle to suppress riding errors leading to accidents
Přibyl, Tomáš ; Liška, Jiří (referee) ; Zuth, Daniel (advisor)
Work tackles the general design systems of automatic control of engine power and braking effects so that avoid any unnecessary dangerous situations and to improve the driving characteristics and suppression causes of accident due to bad decisions of driver. Is required to propose a general system based on the draft sensors and control circuits, their relationships, design control processor, which will be without the knowledge of the driver intervene in driving motorcycle.
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Design of Effective Usage of Instructional System
Liška, Jiří ; Endrle, Pavel (referee) ; Škorpil, Vladislav (advisor)
In this bachelor thesis are proposed three new laboratory exercises using TIMS system. Laboratory exercises are focused on digital modulation, multiplexing and measurement errors in transmitting signals with line codes. The laboratory experiments were designed with respect to the practice of the subject matter in an article Access and Transport Networks.
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Fabrication and testing of MEMS device components for micromanipulation
Binková, Petra ; Prášek, Jan (referee) ; Liška, Jiří (advisor)
This diploma thesis deals with the production and testing of MEMS devices intended for micromanipulations with a possibility of their usage in a scanning electron microscope, which includes manipulation of microobjects such as metal microparticles, microfibres or even biological samples. The first chapter contains a detailed study of microsystems and MEMS devices. The next chapter describes various types of micromanipulations, including MEMS. The third chapter deals with possible techniques of microfabrication. The fourth chapter contains experimental part of this work, in which two versions of silicon microgrippers were proposed. Considering available solutions of micromanipulators, principal and spatial limitations in the electron microscope, the piezoelectric actuator was chosen as the gripping principle. Direct write laser lithography and deep reactive ion etching were used to produce the microgrippers, and it was necessary to optimize these techniques for selected application. During the optimizations, various problems were solved, including the elimination of black silicon formation, unsuccessful etching of narrow deep structures, etc. Prototype of one of the proposed microgripper was successfully created. The manufactured micromanipulators were subsequently tested under an optical microscope. During testing, it was necessary to modify the position of the actuator in the device to ensure that the jaws of the manipulator are clamped.
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Porous silicon based optical sensors of chemical species for gas phase
Liška, Jiří ; Dian, Juraj (advisor) ; Červený, Václav (referee)
Title: Porous silicon-based optical sensors of chemical species for gas phase Author: Bc. Jiří Liška Department: Department of Inorganic Chemistry Supervisor: doc. RNDr. Juraj Dian, CSc. Abstract: Porous silicon is a nanostructured material, which is a suitable material for che- mical sensors due to its optical properties, especially photoluminescence and its quenching depending on the chemicals in the environment. Optical sensors based on porous silicon are the most studied group of sensors and have been successfully used for the detection of chemicals in both liquid and gas phases. In addition, the surface of porous silicon can be modified by a number of techniques, thereby modifying the recognition properties. In the case of combining multiple sensor elements of different properties, it is possible to measure multiple responses in the photoluminescent sensor array. The objectives of this thesis are: 1. Extension of electrochemical characterisation of initial silicon substrates using vol- tammetric techniques under different lighting conditions during the experiment, preparation of porous silicon samples from different types of crystalline silicon sub- strates (p-type, n-type), crystallographic orientation and doping degree. 2. Functionalisation of porous silicon surface with new chemical compounds by...
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Fabrication and characterisation of plasmonic antennas on selected thin film with aim to get enhanced absorption due to presence of strong coupling
Vodička, Martin ; Kepič, Peter (referee) ; Liška, Jiří (advisor)
Strong coupling systems offer many important applications in various fields such as photonics, chemistry, nonlinear optics and others. This Bachelor's thesis focuses on the fabrication of metal plasmonic structures suitable for the formation of strong coupling between localized surface plasmon antennas and hexagonal boron nitride (hBN) thin film phonons in the infrared region. In the case of inducing a strong coupling, an increase in absorption should occur, which makes it possible to use this system to fabricate an infrared detector, the so-called microbolometer. The thesis summarizes important findings from electromagnetic field theory, describes the formation of strong coupling from the perspective of classical physics and gives examples of systems with strong coupling. Furthermore, the formation of surface plasmon polaritons and localized surface plasmons (LSPs) is theoretically described. Plasmonic antennas, their fabrication, applications and physical properties of hBN are described. In the practical part of the thesis, fabrication of plasmonic antennas under or on hBN thin film has been realized. The fabricated samples were characterized by scanning electron microscopy and the spectral response was measured by Fourier transform infrared spectroscopy. In the spectra, the absorption of hBN at 7.3 m was confirmed and additional transmittance minima corresponding to the presence of antennas were detected. The presence of a strong coupling between the LSPs antennas and the phonons of the native SiO2 layer was probably observed. Whether there was a strong coupling between the LSPs antennas and the hBN phonons cannot be inferred from the the obtained results.
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Fabrication and testing of microbolometer or other infrared detector based on plasmonic antennas
Děcký, Marek ; Gallina, Pavel (referee) ; Liška, Jiří (advisor)
This bachelor’s thesis is focused on study and fabrication of infrared detectors. Other than just providing a literature research and plasmonics research into the topic, the main goal of this thesis is to propose new designs, manufacturing and characterization such detectors. Specifically the uncooled microbolometer that uses plasmonic antennas for the amplification of the strong coupling which forms between the localized surface plasmons of golden antennas and a phonons of thin dielectric film made from silicon dioxide. The preparation of several types of microbolometers on silicon substrates was conducted using electron beam lithography, photolithography and by thin film deposition techniques. The individual microbolometers differed mainly in the width of the layers between the temperature sensitive meanders and the antennas, but also in the dimensions of the antennas. In the first two sets of microbolometers, the meanders were made from titanium, however meanders in the last set of microbolometers were fabricated from platinum. Reaction of the microbolometers on visible and infrared radiation was tested using measurement of electrical resistance. It was discovered that fabricated microbolometers with titanium meanders significantly reacted on visible light by lowering their resistance. This means they behave like semiconductor. Microbolometers also reacted on infrared radiation by lowering their resistance, but only when temperature of black body source exceeded 400 °C. Reaction on visible and infrared radiation was not observed on microbolometers with platinum meanders with one exception.
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Factors affecting mortality in countries with the highest life expectancy at birth with focus on the influence of tobacco smoking
Liška, Jiří ; Hulíková Tesárková, Klára (advisor) ; Burcin, Boris (referee)
Factors affecting mortality in countries with the highest life expectancy at birth with focus on the influence of tobacco smoking Abstract This bachelor thesis focuses on the factors influencing mortality levels, specifically analysing the influence of tobacco smoking in countries with highest life expectancies - Japan and Switzerland. Trends in smoking prevalence rates from the mid-20th century to the present are analysed. In both countries, the prevalence of smoking is higher in men than in women, but the gap is narrowing over time. Then, author constructs life tables using data from WHO Mortality Database and analyses mortality in Japan and Switzerland between 1995 and 2017, focusing on life expectancy at birth and at ages of 35 and 65 years. The actual development of these indicators is compared with two hypothetical developments, assuming the elimination of smoking attributable mortality and a constant level of smoking attributable mortality. The results indicate that high life expectancies in Japan and Switzerland are not caused by low numbers of smokers in these countries. Keywords: mortality, life expectancy, determinants of health, smoking, Japan, Switzerland
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Plasmonically active nanostructures for optical filtering
Idesová, Beáta ; Liška, Jiří (referee) ; Rovenská, Katarína (advisor)
This bachelor’s thesis deals with optical color filters composed of plasmonically active nanostructures and studies the parameters which influence the performance of such filters. Using electron beam litography and selective reactive ion etching, plasmonic hole-like filters were prepared in alumina film on fused silica substrate. The fabricated arrays of nanostructures, acting as optical filters, varied in shape and size of the nanostructures, distances among the nanostructures and their lateral arrangement within the arrays. The influence of these factors on transmission spectra of plasmonic filters was experimentally analysed using optical spectroscopy. A majority of the observed alternations of the measured transmission spectra was consistent with the research study which is, as well, part of this thesis. The highest color filtering selectivity was observed in arrays with divided square structure shape which also exhibited decent transmittance.
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Photoluminescence sensor field applied for detection of chemical compounds in gas mixtures
Liška, Jiří ; Dian, Juraj (advisor) ; Broncová, Gabriela (referee)
Title: Photoluminescence sensor field applied for detection of chemical compounds in gas mixtures Author: Jiří Liška Department: Department of Analytical Chemistry Supervisor: doc. RNDr. Juraj Dian, CSc. Abstract Porous silicon is a nanostructured material that can be prepared by galvanic etching of silicon in the presence of hydrofluoric acid. The properties of this material can be influenced by way of preparation or by the chemical modification of the surface. Porous silicon has many extraordinary properties as compared to macrocrystalline silicon; the most important one for chemical sensing is the visible photoluminescence at room temperature. In the presence of organic and inorganic analytes in the gas phase, the photoluminescence of the material is quenched. This phenomenon can be used for chemical sensors of chemical compounds in the gas phase. These sensors are very sensitive and give reasonable results for organic compounds. Photoluminescence sensor field uses for measurement several sensor elements with the modified surface. It is possible to use this method for the identification and determination of gaseous organic compounds. The aim of this thesis was: 1. the preparation of porous silicon samples, 2. the modification of surface with different methods, 3. the characterization of samples with FTIR...
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