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Fiber optic sensors
Janďourek, Leoš ; Šifta, Radim (referee) ; Čučka, Milan (advisor)
Term paper deals with optics, optical fibers and in particular with optical sensors, which are described in more detail. Furthermore, we introduce a new simulation program from VPI photonics. We will show the user interface and the possibiliti of sumulation in it.
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Fiber-Optic Sensors
Dejdar, Petr ; Róka,, Rastislav (referee) ; Kyselák, Martin (referee) ; Münster, Petr (advisor)
Optical networks are continuously expanding and this creating space for the use of optical fibers for non-data transmissions. One of them is the use for sensing purposes, where optical fibers can be used to measure temperature, pressure, vibration, etc. In standard conditions or in conditions where the placement of conventional sensors is not suitable (increased humidity, radiation, lack of space, etc.).This paper is devoted to the comparison of technologies comparing sensing systems and describes their principle and their possible applications. Subsequently, the different systems are built and tested. Possible improvements are then proposed based on the measurements, where for the reflectometric system the advantages of using edge detection algorithms are quantified. For the polarization detectors, improvements are made using machine learning classification algorithms with classification success rates above 97 %. Detailed measurements of the sensitivity of optical fibers to acoustic vibrations in three different environments, with different path configurations, cables, vibration-damping materials, etc. are also described. These measurements proved the possibility of intercepting optical fibers using interferometric, reflectometric, and polarization systems, where the polarization system is proven to be the least sensitive and records only lower frequencies. Based on these measurements, a system for securing the physical layer of optical networks is then proposed, which is able to accurately distinguish the quiescent and cable manipulation states from the datasets we created.
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Research and Development of 2D/3D Deformable Structures LTCC for Optoelectronic Applications
Somer, Jakub ; Pietriková,, Alena (referee) ; Husák, Miroslav (referee) ; Szendiuch, Ivan (advisor)
The doctoral thesis is focused on the research, development and production of deformation elements produced by LTCC technology for use in optoelectronic applications. A study of technological processes is carried out, with the emphasis on achieving accurate and reproducible mechanical component manufacturing so that these can be used on standard LTCC substrates in the commercial sphere. Therefore, available standard thick-film materials are used. The work also involves testing the suitability of the use of standard LTCC materials for selected sensory applications in which fiber optics are used to confirm the usefulness of the results achieved in practice. The dissertable core of the work is research and development of a technology using new principles and possibilities hidden in the mechanical parameters of LTCC structures, which are designed and used for the realization of deformation elements. The work also involves testing the suitability of the use of standard LTCC materials for selected sensory applications in which fiber optics are used to confirm the usefulness of the results achieved in practice.
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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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development of fluorosenzor based on chemically modified electroluminescence diods.
Blažková, Ivona ; Jelínek, Ivan (advisor) ; Dejmková, Hana (referee)
Luminescence sensors based on LED were prepared by modification of LED poly- carbonate surface and following binding of luminescence dyes on this surface. Two methods of modification were utilized. The first one was the oxidation of the surface yielding free carboxylic groups. Such modified LEDs were then covered by cationic cresyl violet dye. The second modification consisted of nitration and consequent reduction to free amino groups followed by binding of anionic sulforhodamine dye. The stability of emission and the stability of dye binding were studied. Then, the response of constructed sensors to toluene as analyte in gas and liquid phase was measured.
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Research and Development of 2D/3D Deformable Structures LTCC for Optoelectronic Applications
Somer, Jakub ; Pietriková,, Alena (referee) ; Husák, Miroslav (referee) ; Szendiuch, Ivan (advisor)
The doctoral thesis is focused on the research, development and production of deformation elements produced by LTCC technology for use in optoelectronic applications. A study of technological processes is carried out, with the emphasis on achieving accurate and reproducible mechanical component manufacturing so that these can be used on standard LTCC substrates in the commercial sphere. Therefore, available standard thick-film materials are used. The work also involves testing the suitability of the use of standard LTCC materials for selected sensory applications in which fiber optics are used to confirm the usefulness of the results achieved in practice. The dissertable core of the work is research and development of a technology using new principles and possibilities hidden in the mechanical parameters of LTCC structures, which are designed and used for the realization of deformation elements. The work also involves testing the suitability of the use of standard LTCC materials for selected sensory applications in which fiber optics are used to confirm the usefulness of the results achieved in practice.
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Detekce napadení obilnin listovými chorobami pomocí termálního zobrazování, zobrazovací fluorescence a spektrální odrazivosti
Mezera, Jiří
In the theoretical part of this thesis there is summarized the basic knowledge about the fungal leaf diseases of cereals, their harmfulness and technologies of precision agriculture. The practical part deals with the detection of cereal infestation with fungal leaf diseases using noninvasive optical methods. The research was conducted on winter wheat using methods based on spectral reflectance, infrared thermal imaging, chlorophyll fluorescence imaging, and blue-green fluorescence imaging. The tested diseases were powdery mildew (Blumeria graminis f. sp. tritici), wheat stripe rust (Puccinia striiformis), and wheat leaf rust (Puccinia recondita f.sp. tritici).). In the case of spectral reflectance, the best results were obtained for spectral indices ANMB650-725 and ZM generally. Overall, the best results for all methods were achieved in the detection of wheat leaf rust. A very good indicator of disease infestation was infrared thermal imaging, with a higher level of infection implying an increase in leaf temperature and a lower difference between leaf and air temperature. Reliability of detection by chlorophyll fluorescence imaging differs between individual diseases, with the best results being generally achieved for actual quantum yield PSII and the non-photochemical quenching. The most promising method for the future is the blue-green fluorescence imaging, which achieved very good results for both, the estimation of infection level and contrast between the infected and the healthy part of the leaf.
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Using distance sensors as sensors for counting persons
Engel, Michal ; Krajsa, Ondřej (referee) ; Novotný, Vít (advisor)
The subject of this work is the use of sensors to measure distance for counting people. First, I focus on the general description and physical principles of photo sensors and their parameters. Then I focus on the general description and physical principles ultrasonic sensors and their parameters. Follows discribe sensors which can be used for counting peoples. Followed by measuring workplace design and it is implementation. The last section is devolted to design algorithms for data processing.
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development of fluorosenzor based on chemically modified electroluminescence diods.
Blažková, Ivona ; Jelínek, Ivan (advisor) ; Dejmková, Hana (referee)
Luminescence sensors based on LED were prepared by modification of LED poly- carbonate surface and following binding of luminescence dyes on this surface. Two methods of modification were utilized. The first one was the oxidation of the surface yielding free carboxylic groups. Such modified LEDs were then covered by cationic cresyl violet dye. The second modification consisted of nitration and consequent reduction to free amino groups followed by binding of anionic sulforhodamine dye. The stability of emission and the stability of dye binding were studied. Then, the response of constructed sensors to toluene as analyte in gas and liquid phase was measured.
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Fiber optic sensors
Janďourek, Leoš ; Šifta, Radim (referee) ; Čučka, Milan (advisor)
Term paper deals with optics, optical fibers and in particular with optical sensors, which are described in more detail. Furthermore, we introduce a new simulation program from VPI photonics. We will show the user interface and the possibiliti of sumulation in it.
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