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The Study of Transient Species and Precursors of Biomolecules using Spectroscopic Techniques
Ferus, Martin ; Civiš, Svatopluk (advisor) ; Šponerová, Judit E. (referee) ; Wild, Jan (referee)
The presented thesis is focused on a spectroscopic study of unstable radicals, ions and molecules in a positive column glow discharge and laser plasma. The research of these fragments is supplemented by a study of biomolecules formation from these species and influence of catalysts. Molecular dynamics of radicals, ions and unstable molecules has been studied using a time resolved Fourier transform infrared spectroscopy. Time resolved spectra of CH4, HCONH2, BrCN, CH3CN, CF3Br, (CF3)2CHBr positive column glow discharges have been measured and simulated using a kinetic model including molecular dynamics, collisions and chemical and radiation transfer processes. The model has been compared with our experimental results and time resolved spectra were described in details. Fit to a complex reaction mechanism has been used to estimate a rate constant of a HCN conversion to HNC by a collision with H radical. The study of precursors of biomolecules was focused on chemical consequences of a laser induced dielectric breakdown in formamide vapor and gaseous carbon monooxide with 18 O labeled water. Dissociation products have been detected using the Fourier transform absorption spectroscopy. The experimental results have been explained by a help of a chemical laser spark dynamics model. Additionally, our the...
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Optimization of a high current pulse discharge in gas filled capillary for application purposes - Ar8+ laser 46.9 nm
Štraus, Jaroslav ; Koláček, Karel (advisor) ; Jančárek, Alexandr (referee) ; Wild, Jan (referee)
The aim of the thesis was to complete the development of the Czech version of the extremal ultraviolet (XUV) argon capillary laser working at the wavelength 46.9 nm and its adaptation for the first practical applications. A multi-discipline complex of mutually interconnected problems was analyzed and studied: The reasons for a capillary low life-time were investigated using defectoscopic methods, a pre- pulse regime influence was studied with the help of spectroscopy on a physical model. By performing necessary construction and technology changes as well as by the multi-parametric optimisation of working regime, the indicated weaknesses were suppressed. The XUV laser was focused into a footprint of the size about 100 µm and the apparatus was extended by a set of practical aids and accessories for special applications, especially for exposition of the samples at extreme temperatures. As practical applications of the XUV laser, measurements of multilayer mirror reflectivity and filter transmissivity were performed. Using the XUV laser for a thin layer deposition and radiation resistance testing was verified to be practicable in principle. Probably a first temperature dependence of an XUV laser ablation rate was measured, in the temperature range from -180 deg.C to +200 deg.C, on BaF2.
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Fourier transform infrared spectroscopy: application in a study of transient species in discharge and ablation plasma
Kubelík, Petr ; Civiš, Svatopluk (advisor) ; Wild, Jan (referee) ; Rohlena, Karel (referee)
The present dissertation consists of two thematically related parts. The first one (includes two publications) deals with the study of chemical pro- cesses and spectroscopy of highly reactive particles produced in the discharge plasma. This part includes the analysis of ro-vibronic CN radical transitions in the infrared region and the study of chemical reactions in pulsed dischar- ges. The discharge was used as a tool for research of decomposition of simple precursors (acetonitrile, formamide and BrCN) and the subsequent formation of intermediates and reaction products in plasma. The obtained experimental results were interpreted using a numerical model developed in context of this work and used to simulate the kinetics of the studied systems. The second part (includes seven works) is aimed at high-resolved spectro- scopy of metals in the ablation plasma. A total of six different metals were studied: Au, Ag, Cu, Cs, K and Na. The main motivation for spectroscopic research on metals in the infrared region is to obtain information on atomic metals transitions, which are particularly important for astronomical identi- fication of lines in the spectra of stars and their spectroscopic assignments. Each publication contains a summary of the analyzed atomic transitions of which a considerable portion had not...
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Experimental study of electron and ion temperatures in impact plasmas
Kočiščák, Samuel ; Pavlů, Jiří (advisor) ; Wild, Jan (referee)
Title: Experimental study of electron and ion temperatures in impact plasmas Author: Samuel Kočiščák Department: Department of Surface and Plasma Science - DSPS Supervisor: doc. RNDr. Jiří Pavlů, Ph.D., DSPS Abstract: In-situ analysis of a hypervelocity grain impact is a complex discipline, making use of multiple physical phenomena. An important one, if not the most important one, being a dust impact ionisation. Future experiments could benefit substantially from better understanding of the phenomenon. The goal of this work was a study of the impact ionisation per-se, with the objective: to experimentally determine the effective temperatures of post-impact charged ejecta. Importance of this parameter is obvious, although different approaches scarcely ever report similar results. Our way was the analysis in a retarding potential analyzer. Firstly, large data set of laboratory data from dust accelerator was analyzed, secondly a Monte Carlo study of the results and the analyzer itself was performed. Lastly, recommendations for future in-situ experiments are provided based on our results. Keywords: impact plasmas cosmic dust impact ionization
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Characterization and focusing of capillary-discharge XUV-laser beam for purposes of thin-film deposition
Pira, Peter ; Wild, Jan (advisor)
Title: Characterization and focusing of capillary-discharge XUV-laser beam for purposes of thin-film deposition Author: Peter Pira Department: Department of Surface and Plasma Science Supervisor: doc. RNDr. Jan Wild, CSc., Department of Surface and Plasma Science Abstract: The paper deals with the first results of the interaction of a desk-top high repetition rate XUV laser (wavelength of 46.9 nm) radiation with materials suitable for optoelectronics, in particular the ionic crystals CsI, LiF, etc. Using surface physics methods (AFM, DIC Normanski microscopy) pulse laser imprints were investigated. Based on the results obtained, general information on the nature of ablation and desorption was obtained, which were compared with the results of the XUV-ABLATOR modified code modeling. Plasma arising from ablation was examined by a modified Langmuir probe system. The main result is the pulse laser deposition of thin films of Bi and CsI. Keywords: ablation, Pulsed Laser Deposition, XUV laser
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Methodology for predictive mapping of rare and endangered bryophytes distribution in the Czech Republic
Man, Matěj ; Wild, Jan
The methodology introduced certified procedure of using species distribution modelling to support discovery of new localities with presence of rare species of bryophytes and lichens in Czech Republic. The procedure available for general public, it provides algorithms, computation power and environmental data. User provides training data – coordinates of species presence. From the software interface it is also possible to request the coordinates directly from Database of Lichens and Bryophytes (DaLiBor). Georeferenced map is the output form the software. The aim of the methodology is to provide integrated tool for conservation planning and research to promote the bryological and lichenological field survey in Czech Republic. The methodology will help to focus the survey which could make the survey more efficient and cheaper according to money but also human resources. The methodology is based exclusively on free software, mostly open source and free licence. In the Czech Republic, the methodology provides modern software approach to target botanical research. In national practical nature conservation, it is all new application of established procedure from other fields.\n
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Methodology of processing hemispherical photographs
Brůna, Josef ; Wild, Jan ; Hederová, Lucia ; Klinerová, Tereza ; Macek, Martin
The methodology of processing hemispherialc photographs is a complex set of activities, starting with the creation of an image with a fish-eye lens, image editing in graphic editors and ending with analysis in specialized software. The obtained data indicate the amount of radiation falling into the undergrowth and the method of processing affects their quality. The procedure developed by the GIS and Remote Sensing Department of BU CAS integrates methods from various programmes into a script in R.
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Characterization and focusing of capillary-discharge XUV-laser beam for purposes of thin-film deposition
Pira, Peter ; Wild, Jan (advisor)
Title: Characterization and focusing of capillary-discharge XUV-laser beam for purposes of thin-film deposition Author: Peter Pira Department: Department of Surface and Plasma Science Supervisor: doc. RNDr. Jan Wild, CSc., Department of Surface and Plasma Science Abstract: The paper deals with the first results of the interaction of a desk-top high repetition rate XUV laser (wavelength of 46.9 nm) radiation with materials suitable for optoelectronics, in particular the ionic crystals CsI, LiF, etc. Using surface physics methods (AFM, DIC Normanski microscopy) pulse laser imprints were investigated. Based on the results obtained, general information on the nature of ablation and desorption was obtained, which were compared with the results of the XUV-ABLATOR modified code modeling. Plasma arising from ablation was examined by a modified Langmuir probe system. The main result is the pulse laser deposition of thin films of Bi and CsI. Keywords: ablation, Pulsed Laser Deposition, XUV laser
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