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Hydride generation study for arsenic speciation analysis with AAS and AFS detection
Svoboda, Milan ; Dědina, Jiří (advisor) ; Spěváčková, Věra (referee) ; Komárek, Josef (referee)
The general aim of this work was a development of methodology and instrumentation for speciation analysis based on the combination of the selective generation of substituted hydrides with atomic absorption or atomic fluorescence spectrometry detection. The first topic of this work was the development of methodology and instrumentation for arsenic speciation analysis based on selective generation of substituted arsines with trapping in the cryogenic trap (U-tube packed with chromosorb) with AAS detection (HG- CT-AAS). The conditions of the selective hydride generation approach as well as working procedure of the cryogenic trap were optimized (appropriate approach for hydride generation, set up of heating program of cryogenic trap, new dryer - cartidge with NaOH, elimination of unspecific absorption, decreasing of the detection limits). The second important part of the work lay in applying of the developed method for arsenic speciation analysis in a homogenized mouse liver tissue. The direct slurry sampling to hydride generator was develop. Moreover the information about oxidation state (iAsIII,V , MAsIII,V a DMAsIII,V ) was obtain. The effect of relevant experimental parameters such as tetrahydroborate concentration, TRIS buffer concentration and time of pre-reduction of the samples by L-cysteine...
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Hydride generation study for arsenic speciation analysis with AAS and AFS detection
Svoboda, Milan
The general aim of this work was a development of methodology and instrumentation for speciation analysis based on the combination of the selective generation of substituted hydrides with atomic absorption or atomic fluorescence spectrometry detection. The first topic of this work was the development of methodology and instrumentation for arsenic speciation analysis based on selective generation of substituted arsines with trapping in the cryogenic trap (U-tube packed with chromosorb) with AAS detection (HG- CT-AAS). The conditions of the selective hydride generation approach as well as working procedure of the cryogenic trap were optimized (appropriate approach for hydride generation, set up of heating program of cryogenic trap, new dryer - cartidge with NaOH, elimination of unspecific absorption, decreasing of the detection limits). The second important part of the work lay in applying of the developed method for arsenic speciation analysis in a homogenized mouse liver tissue. The direct slurry sampling to hydride generator was develop. Moreover the information about oxidation state (iAsIII,V , MAsIII,V a DMAsIII,V ) was obtain. The effect of relevant experimental parameters such as tetrahydroborate concentration, TRIS buffer concentration and time of pre-reduction of the samples by L-cysteine...
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Network Infrastructure Design for Family House
Svoboda, Milan ; Jordán, Vilém (referee) ; Ondrák, Viktor (advisor)
This thesis deals with the network infrastructure design for family house. The default aspects for the design of network infrastructure are house plans and requirements of the client. The work presents the theoretical knowledge necessary for further analysis of client requirements and design optimal solution. Part of the work are cabling plans, location of active elements and cost calculations to build the network infrastructure.
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The Implementation of ISMS in a Small Company
Svoboda, Milan ; Vlastimil,, Svoboda (referee) ; Sedlák, Petr (advisor)
The diploma thesis focuses on proposing an information security management system (ISMS) in a small company. This publication includes theoretical facts, which are needed to understand and design a ISMS. The design proposal of the ISMS itself is based on an analysis of the current status of the company's information security. The proposed security measures are based on the actual state of information security within the company, and on recommendations stemming from the ISO/IEC 27000 standard.
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Concept and Development of Single-purpose Scanning Electron Microscope
Foret, Zdeněk ; Vašina, Radovan (referee) ; Starý,, Vladimír (referee) ; Svoboda, Milan (referee) ; Švejcar, Jiří (advisor)
Electron microscopy has become an essential component in many scientific fields, in which it contributes to new discoveries. The microscopy itself is continually being developed and the limits, which seemed to be insurmountable, have been overcome. The instruments have become user friendlier and their mobility enables flexible practical use in the field. The subject of this work is the design of a scanning electron microscope, the calculation of a magnetic curcuit of an immersion objective combined with standard lens, the theoretical calculation of a microscope resolution and the design solution of the mechanical parts of the microscope with a sample manipulator. The thesis includes a description of the electron microscopy development summarizing it briefly from the very beginning up to now. It also deals with electron sources, especially the Shottky cathode, which is to be the main object observed by the proposed device. The work also contains a description of the calculation of the microscope resolution as a function of the current density distribution. Another interesting issue included in the theoretical part is the signal detection, a description of several types of detectors and possible signal processing. The solution of the thesis includes a description of the concept of the scanning electron microscope with an explanation of the distribution of combined lens functions. The optical diagram shows the arrangement of the electron optics system and the distibution of pressure in the chamber of the microscope. The theoretical calculation is devoted to the magnetic curcuit design of the objective and to the resolution of the microscope for a given extent of working distances. Two modifications of the lens were designed – a standard simple objective and a combination of the standard objective with the immersion magnetic one. The results of both modifications are given for the parameters to be compared. The combined objective was designed with the possibility of use in two modes, as a standard and immersion lens. The deflection system is also divided into two modes, as a single deflection for the standard lens and as a two-dimension deflection for the immersion lens. Detectors for secondary electrons (SE) and detectors for back scattered electrons (BSE) will be used for the signal detection. The design of the microscope is another large part, which gives details on the most significant components of the microscope. The content of the technical solution is a three-dimensional computer model, created in Autodesk Inventor, which also includes a sample manipulator driven by piezoelectric actuators.
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Application of Electron Backscatter Diffraction in Materials Engineering
Man, Ondřej ; Vodárek, Vlastimil (referee) ; Svoboda, Milan (referee) ; Švejcar, Jiří (advisor)
The thesis deals with principles and common applications of the electron backscatter diffraction (EBSD) method. Some practical experience in application of the method to a study of highly deformed structure of copper and its thermal stability is described on one hand, and, on the other hand, to a study of phase composition of TRIP steel on various levels of imposed strain. The limitations of EBSD method are discussed along with its resolution in comparison with other complimentary techniques.
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