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Automatic sample tilt compensation for chemical mapping by LIBS
Stříbrná, Klára ; Pořízka, Pavel (referee) ; Prochazka, David (advisor)
This thesis deals with designing an algorithm for slope compensation of a sample examined using the LIBS (Laser-induced breakdown spectroscopy) method. It mainly fucuses on the purpose of elemental mapping. The sample slope noticeably affects the result quality and therefore a demand for a simple and inexpensive solution to this problem appeared that would also be applicable for commercial uses of LIBS.
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Fluorine detection by means of Laser-Induced Breakdown Spectroscopy
Jaworková, Magdalena ; Pořízka, Pavel (referee) ; Prochazka, David (advisor)
This work concerns the Laser Induced Break-down Spectroscopy LIBS and it´s usage in detection of fluorine in specimens. This method and the particular methods of measurements suitable for fluorine detection are analysed in theoretical part. The sensitivity of particular methods such as usage of buffer gases (He), change of ambient pressure, usage of double laser pulse (DP–LIBS) or detection of molecular bands are compared in experimental part.
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Design of collection optics for in-situ Laser-Induced Breakdown Spectroscopy analysis
Švábíková, Anna ; Novotný, Jan (referee) ; Pořízka, Pavel (advisor)
The subject of this bachleor thesis is an optomechanic design for a remote laser induced breakdown spectrometry (LIBS) apparatus. The aim of the bachleor thesis is a design of focusing and collecting optics due to given parameters. This work presents general theoretical basics of LIBS. However, particular attention is given to the description of LIBS instrumentation. Part of this work is a research on remote LIBS anaylysis, particularly on its instrumentation. In the construction part, several optical designs are presented and thereafter the one with best parameters is chosen. The nal output of this thesis is optimisation of chosen optical desing, followed with a construction design of focusing and collecting optics with enclosed drawing documentation.
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Effect of magnetic field on laser-induced plasma characteristics
Vrábel, Jakub ; Pořízka, Pavel (referee) ; Prochazka, David (advisor)
This work is based on topic of laser induced breakdown spectroscopy „LIBS“ and its application to chemical analysis of materials. Paper presents a brief theoretical basis of LIBS with focus on effect of magnetic field to plasmas and modeling spectras for calib-ration-free LIBS analysis. Considerable part of work is dedicated to practical demon-stration of modeling spectras, using Matlab and interpretation of experimental results. The final output is automatized method for evaluation of spectras, which could leads to calibration-free LIBS analysis. Also there is an effort to increase sensitivity of method.
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Interconnection of Restricted Boltzmann machine method with statistical physics and its implementation in the processing of spectroscopic data
Vrábel, Jakub ; Hrdlička, Aleš (referee) ; Pořízka, Pavel (advisor)
Práca sa zaoberá spojeniami medzi štatistickou fyzikou a strojovým učením s dôrazom na základné princípy a ich dôsledky. Ďalej sa venuje obecným vlastnostiam spektroskopických dát a ich zohľadnení pri pokročilom spracovaní dát. Začiatok práce je venovaný odvodeniu partičnej sumy štatistického systému a štúdiu Isingovho modelu pomocou "mean field" prístupu. Následne, popri základnom úvode do strojového učenia, je ukázaná ekvivalencia medzi Isingovým modelom a Hopfieldovou sieťou - modelom strojového učenia. Na konci teoretickej časti je z Hopfieldovej siete odvodený model Restricted Boltzmann Machine (RBM). Vhodnosť použitia RBM na spracovanie spektroskopických dát je diskutovaná a preukázaná na znížení dimenzie týchto dát. Výsledky sú porovnané s bežne používanou Metódou Hlavných Komponent (PCA), spolu so zhodnotením prístupu a možnosťami ďalšieho zlepšovania.
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Design of compact spectrograph with shiftable spectral range based on transmission gratings
Malina, Jan ; Pořízka, Pavel (referee) ; Novotný, Jan (advisor)
The aim of this diploma thesis is to design a compact spectrometer with a transmission grating and a shiftable spectral range for the method of laser-induced breakdown spectroscopy (LIBS). The work in the theoretical part contains a basic description of spectroscopy and spectroscopic methods of LIBS, spectrometer and its individual parts. The practical part describes the spectrometer design procedure, introduces selected components and comments on the reason for their selection. Selected components are assembled into the final form of a spectrometer, which is further tested with the help of a simulation program to confirm its functionality. The result of the work is a comprehensive overview of the individual components of the spectrometer, aspects of its construction together with instructions and advice on its assembly, along with an example in the form of a designed set of commonly available catalog components.
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Development of universal software interface for detection units in optical spectroscopy
Belica, Martin ; Pořízka, Pavel (referee) ; Žalud, Luděk (advisor)
This master's thesis deals with the design and implementation of universal user interface for detection devices used in Laser-induced breakdown spectroscopy. The design and implementation are based on analysis of current state of instrumentation used in laser spectroscopy. The user interface should be able to work with high repetition frequency of measurement. Acquired spectra should be visualised to user and it is also necessary to save this data on hard drive. The resulting application must be universal. It means the application must support various types and vendors of detection devices.
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Design of optomechanical module for chemical mapping using Laser-Induced Breakdown Spectroscopy
Švábíková, Anna ; Samek, Ota (referee) ; Pořízka, Pavel (advisor)
Tato diplomová práce se zabývá návrhem optomechanického modulu pro chemické mapování metodou spektroskopie laserem buzeného plazmatu (LIBS). Cílem je vyvinout modul, který bude umožňovat analýzu spektrálních čar zinku v ultrafialové (UV) oblasti. V práci jsou popsány teoretické základy metody LIBS a následně je provedena rešerše zaměřená na problematiku dálkové LIBS analýzy. V diplomové práci jsou prezentovány možné optické návrhy fokusační a sběrné optiky, z nichž jsou vybrané následně otestovány. Výsledkem práce je konstrukční návrh modulu.
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