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RF detection method of explosives and drugs - NQR
Motyčka, Lukáš ; ČR,, MBA - ÚPT AV (referee) ; Kratochvíl, Tomáš (advisor)
The thesis deals with RF spectroscopic methods, which are applicable for the detection of hazardous substances such as explosives or drugs. Particular attention is focused on promising method of nuclear quadrupole resonance. Abroad this method has recently been applied in the detection of energetic materials in hazardous locations. The cornerstone of the nuclear quadrupole resonance is to evaluate the interaction between electromagnetic radiation, in the range of medium to very short waves, and the researched substance. Observed parameter are the resonant frequencies of the substance. Spectral analysis of signal is used for their evaluation. Resonant frequencies are always typical for the crystalline structure, therefore every explosive or drug is clearly identifiable by this method.
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Detection of Braking Tracks using Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Fluorescence Spectroscopy (LIBS + LIFS)
Prochazka, David ; Vémola, Aleš (referee) ; Pína,, Ladislav (referee) ; Kaiser, Jozef (advisor)
The aim of this work is to investigate the potential of Laser-Induced Breakdown Spectroscopy (LIBS) for identification of visually unrecognizable braking tracks. Identification of these tracks is based on different chemical composition of tire tread in comparison to road surface. The investigation was divided in several sequential steps – selection of suitable chemical element and its spectral line for break tracks identification; determination of the limits of detection and threshold intensity respectively for the selected chemical element; verification of LIBS ability to detect braking tracks on a real braking track. This testing braking track was prepared by exactly defined and described conditions. The detection was performed in two ways – laboratory analysis of tire treads particles collected via adhesive tape and in situ analysis via mobile apparatus. Results of both measurements showed that LIBS is able to detect visually unrecognizable braking tracks. Concepts of the devices capable of routine braking tracks identification for both possibilities were introduced.
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Analytical methods applied for the evaluation of environmental contamination by uranium ore mining
Bílek, Jiří ; Holubová, Zuzana (referee) ; Čáslavský, Josef (advisor)
This thesis deals with the testing procedures used in monitoring of environmental contamination after uranium ore mining in the uranium mine in Dolní Rožínka. It deals with the determination of radioactive elements radium, uranium and radon. The methods used for the determination of radioactive elements in mine laboratory in Dolní Rožínka are described. The thesis also mentions other applicable methods for determination of uranium. The metods of determination of manganese, iron and other metallic elements are also summarized in brief.The values of concentrations of monitored analytes in selected locations are presented at the end of the thesis. These values, which were provided by laboratories in Dolní Rožínka, are valid for 2010.
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Wedgewise correction for laser spectroscopy measurements
Schiffer, Štěpán ; Novotný, Jan (referee) ; Klus, Jakub (advisor)
One of the areas where LIBS is used is the creation of chemical maps of studied samples. Measurements made by this method are significantly influenced by the lens to sample distance. At the wedgewise samples this distance is changing during the measurement which decreases the quality of the chemical maps created. In this bachelor’s thesis a method of wedgewise correction is proposed and experimentally verified. A part of this thesis is a description of basics of laser spectroscopy and a summary of some variables influencing the LIBS experiment. The main part of the thesis is a proposal of wedgewise correction algorithm. At the end the results of measurement with the use of the proposed method are presented.
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Properties of graphenoid layers
Mach, Radoslav ; Čech, Ondřej (referee) ; Vaněk, Jiří (advisor)
Master thesis “Properties of graphenoid layers” deals with materials of graphenoid nature such as graphene, graphene oxide and its reduced state. The paper effectively summarize basic theoretical knowledge in the first half of its range. In the second half the project deals with practical part consisted of experiments with application of graphene oxide solvents, its analysis and especially comparing properties of non-reduced graphene oxide with its chemically reduced form. Material is examined in a form of applied thin layers on different substrates.
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Shielding and detection of neutrons
Černý, Tomáš ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
The master’s thesis provides an overview of available neutron sources in terms of neutron yields and energy spectrum of emitted neutrons. Reactions of neutrons with matter, especially neutron scattering and radiation capture, are described. The possibilities neutron neutron detection and spectrometry are also described. The following experiment deals with a design of suitable shielding materials and the analysis of the moderated energy spectrum of neutron flux. The properties of the neutron field were measured using detection by activation. Subsequently, a simulation of the problem was performer in the MCNP program. In the end, the achieved results are compared and evaluated.
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Analysis of Historical Pharmaceutical Preparations Containing Alkaloids, Sulphonamide, Derivatives of Barbituric Acid, and Derivative of Pyrazolone
Kudláček, Karel ; Nesměrák, Karel (advisor) ; Bosáková, Zuzana (referee)
Pharmaceutical preparations of quinine (injection solutions), sulfanilamide, aminophenazone, barbital (tablets), caffeine, phenobarbital (dragee), and theophylline (suppositories) about seventy years old were analyzed using RP-HPLC. Samples were quantified by HPLC-UV and UV-spectrophotometry. Products of degradation were identified using HPLC-UV and HPLC-MS. Conditions of separation were optimized. The samples of quinine injection solutions consist of 92% or 87% of declared quinine content. Quinotoxine has been identified as the product of quinine degradation. The quantification of theophylline in suppositories and caffeine in dragee did not show any degradation after more than 67 years from their manufacturing. Decrase of potent amount (decrase about 8-22 %) were found in drugs containing sulfanilamide, barbital, phenobarbital and aminophenazone. Products of degradation of these pharmaceuticals were not found.
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A novel AAS atomizer based on a dielectric barrier plasma discharge
Novák, Petr ; Kratzer, Jan (advisor) ; Kanický, Viktor (referee)
Atomization of arsine in a novel hydride atomizer for atomic absorption spectrometry (HG-AAS) was thoroughly optimized. This plasma atomizer is based on a dielectric barrier discharge (DBD). Sensitivity and detection limit reached 0.48 s ng-1 As and 0.16 ng ml-1 As, respectively, under optimum atomization conditions (Ar discharge using a flow rate of 60 ml min-1 Ar, DBD power 17 W). Analytical figures of merit reached in DBD are comparable to those found in an externally heated quartz tube multiatomizer (MMQTA) that was chosen as a model of conventional approach to hydride atomization in HG-AAS. An extent of interferences (Se, Sb, Bi) during As determination was investigated comparing both MMQTA and DBD atomizers. The later one was found to be more resistant towards interferences. A simple preconcentration of As in a DBD atomizer was reached after oxygen introduction into the Ar plasma in the DBD resulting in analyte retention in the atomizer followed by its volatilization once the oxygen flow is switched off. Preconcentration efficiency of 100 % was reached and detection limit improvement by a factor of ten was achieved (0.01 ng ml-1 As, preconcentration period 300 s).
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