National Repository of Grey Literature 88 records found  beginprevious48 - 57nextend  jump to record: Search took 0.01 seconds. 
Optical device for breath CO2 concentration analysis
Škorpík, Daniel ; Milek, Jakub (referee) ; Čmiel, Vratislav (advisor)
This Master's thesis discusses about the measurement of the carbon dioxide concentration in breathing by an optical analyzer using infrared absorption spectroscopy. The method is described with the technical focus on individual components needed for subsequent implementation. A circuit diagram is created to produce Arduino platform devices that serve as hardware to connect and power individual parts and software to create a user environment, followed by a Bluetooth module to transmit measured data to mobile devices where real-time results are presented.
Application of modern analytical methods for the study of selected boron coordination compounds
Hrušková, Helena ; Jelínek, Ivan (advisor) ; Dian, Juraj (referee)
This thesis is focused on the study of boron coordination compounds, specifically boron pyrogallol and 2,3-dihydroxynaphthalene ligand complexes. In the introductory part of the work are discussed the properties of boron compounds, their preparation, the possibility of separation by capillary electrophoresis and methods of structural characterization. In the first part of the thesis, the methods of preparation of complexes are discussed and for each complex the optimal yield response is chosen. The resulting products were studied by low resolution mass spectrometry. In the second part of the thesis, structures of complexes, including their modeling in the Gaussian program, were described more precisely. Furthermore, the complexes were characterized by high resolution mass spectrometry. The complexes were also studied by 11 B, 1 H and 1 H COSY NMR and IR spectroscopy. The third part was devoted to the separation of these substances from the mixture after the reaction. CE-UV and CE-MS techniques were used for this purpose. To convert the results, the separation method was developed in ammonium formate buffers that are compatible with both instruments. The equilibration between complexes and ligands was also monitored by CE-UV. A special chapter is the study of pyrogallol autooxidation by UV-VIS and...
Low temperature plasma diagnostics by Cavity Ring-Down Spectroscopy
Kassayová, Miroslava ; Dohnal, Petr (advisor) ; Morávek, Matěj Jan (referee)
Low temperature plasma occurs in interstellar gas clouds, solar system, ionosp- here of the Earth and is used in plasmatic technologies. The study of the reactions of simple atomic or molecular ions with molecules and electrons in low temperature plasma allows better understanding of chemical processes in interstellar gas clouds and atmospheres of gas giants and gives feedback for quantum mechanical calcula- tions. It also allows to connect new facts gained via astronomical observations. The parameters of plasma (kinetic and rotational temperature of ions, their concentra- tions, etc.) may vary and many diagnostic technics are used to determine them. The aim of this bachelor thesis is to find suitable infrared transitions of N2H+ and utilize them for spectroscopical study of the electron - ion recombination of N2H+ ions with electrons. 1
Metallic nanostructures with three-dimensional topography for plasmonics
Rovenská, Katarína ; Kvapil, Michal (referee) ; Ligmajer, Filip (advisor)
Due to high concentration of free electrons, metallic nanostructures can support plasmonic resonances. The spectral shape of plasmonic resonances may be tuned by many factors and because of it, the field of their application, given by their capability of focusing light under the diffraction limit, broadens. This thesis deals with fabrication of gold nanostructures by electron beam litography on top of a silicon substrate. The topography of the substrate is subsequentially modified by wet anistropic etching. A part of this thesis also briefly reviews methods for fabrication of nanostructures with planar or three-dimensional topography. Using the infrared spectroscopy, this thesis further analyzes the effect of size, shape, spacing of the nanostructures, and also the substrate topography on the optical response of the fabricated nanostructures. The outcomes of this thesis verify previously described tendencies of spectral relations between optical properties and named parameters in the mid-infrared region.
Composition and microstructure of plasters in convent of the Želiv Monastery (Czech Republic)
Rezek, P. ; Martinec, Petr ; Ščučka, Jiří ; Majstríková, T.
The paper deals with analyses of composition and structure of historic plasters from the convent building of the Želiv Monastery (Czech Republic). Composition and microstructure of plaster samples taken from the historic object have been assessed using both traditional and advanced analytical methods. The following techniques have been used for the assessment of binders and fine aggregates in plasters: optical microscopy of thin sections, mineralogical and petrographic analysis of separated components, infrared spectroscopy, and thermal analysis. Presented results show significant differences in character of the studied materials of varying age and demonstrate the effectiveness of the taken analytical approach.
Preparation and characterization of silicon-based materials
Šlechta, Miroslav ; Dian, Juraj (advisor) ; Jelínek, Ivan (referee)
Title: Preparation and characterization of silicon-based materials Author: Miroslav Šlechta Department: Department of Chemical Physics and Optics Supervisor: doc. RNDr. Juraj Dian, Csc., Department of Chemical Physics and Optics Abstract: Porous silicon is nanostructured material based on silicon. He was prepared by anodic etching of crystalline silicon in hydrofluoric acid. Physical and chemical properties of porous silicon nanocrystals resulting from the dimensions, which range from units to tens of nanometers. For nanostructured silicon compared to crystalline silicon, exhibit unique properties that depend on the degree of quantum dimensional phenomena and phenomena on its large internal surface. Suitable choice of the silicon substrate, particularly in terms of conductivity and crystallographic orientation, and technological conditions (in particular electrolyte composition, the etching time and current density) can be prepared nanostructured materials of different pore sizes - macroporous, mesoporous and microporous silicon and varying representation Si-O and Si-H bonds. Morphology and chemical composition of the surface of porous silicon allows to think of it as a suitable material for a range of applications - particularly chemical sensors and biosensors, optoelectronics and biomedical applications....
Characterization of proteins of 2'-5' oligoadenylate pathway by means of vibrational spectroscopy
Víšová, Ivana ; Kopecký, Vladimír (advisor) ; Bednárová, Lucie (referee)
The work concerns to structural characterization of two important proteins of 2'-5' oligoadenylate pathway participating in an immune response of organism to a viral infection. Studied proteins were ankyrin domain of mouse RNase L, the C-terminal part of human phosphodiesterase 12 and the complete human phosphodiesterase 12. The proteins were characterized by Raman spectroscopy, infrared spectroscopy, electronic circular dichroism, dynamic light scattering and in addition by two non-spectroscopic methods- differential calorimetry and electrophoresis. For each protein the secondary structures, thermal stability, weight of oligomers and generally a basic characterization by above mentioned methods were provided.
The influence of the quality of articulation UHMWPE inserts on the lifetime of joint replacements
Fulín, Petr ; Pokorný, David (advisor) ; Koudela, Karel (referee) ; Gallo, Jiří (referee)
This thesis focuses on the introduction with the problems of high molecular weight polyethylene (UHMWPE) in orthopedics in the first part. It discusses the history, properties and processes that lead to the failure of UHMWPE joint replacement components. The experimental part validates the hypotheses expressed. It acquaints readers with the experimental verification of the effect of different types of sterilization on the oxidative stability of laboratory prepared samples and explanted UHMWPE joint replacement components using methods of infrared microscopy, electron spin resonance, mechanical tests and tests of microhardness. Other experimental measurements on a large set of explanted components of hip and knee total joint replacements validates the hypothesis that the amount of oxidative damage affects the lifespan of joint replacements. The third part of the experimental study maps the degree of oxidative damage in different places of the hip and knee joint replacements. In the final part we experimentally demonstrate the fact that the rate of oxidative damage has an effect on supramolecular structure of the UHMWPE. From the above experiments are concluded clearly defined recommendations for clinical practice, which should lead to extend the lifespan of total joints replacements in orthopaedics....
Preparation of titanium and zirconium metallocene complexes with pendant nitrile groups
Večeřa, Miloš ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Preparation of metallocene complexes of titanium and zirconium with pendant nitrile groups Miloš Večeřa bachelor thesis Abstract: Two cyclopentadienide salts with pendant nitrile groups were prepared in the form of their corresponding lithium salts and these salts were utilized for the preparation of titanium and zirconium metallocene complexes. One of the ligands was already described in the literature, while the other as well as all the prepared group 4 metallocene complexes are new compounds. Starting materials for these syntheses were 6,6-dimethylfulvene and spiro[2.4]hepta-4,6-diene which, upon a nucleophilic attack by 2-lithio-2-methylpropanenitrile, afforded the corresponding substituted lithium cyclopentadienides, which were characterized by 1 H and 13 C NMR spectroscopy and infrared spectroscopy. Then lithium salts were reacted with Cp*TiCl3 and Cp*ZrCl3 to give the corresponding metallocene dichlorides. Solid-state structures of the prepared titanocene dichlorides were elucidated by means of single crystal X-ray diffraction analysis. The obtained structures allowed a comparison with the known structures of the previously prepared homologous derivative. Unfortunately the corresponding zirconocene dichlorides did not crystallize. Moreover, all the newly prepared metallocenes were characterized by 1...
Salts of 2-aminoethanol and ferrocene-based acids
Zábranský, Martin ; Štěpnička, Petr (advisor) ; Němec, Ivan (referee)
Combination of the compact but sterically flexible ferrocene scaffold with intermolecular binding potential and conformational variability of (2-hydroxyethyl)ammonium structural motif was utilised in the construction of solid crystalline materials. Crystallisation in systems containing ferrocenecarboxylic, 2-ferrocenylacetic, 3-ferrocenylpropionic, 3-ferrocenyl- acrylic, 3-ferrocenylacrylic, 3-ferrocenylpropiolic, ferrocene-1,1'-dicarboxylic or ferrocene- sulfonic acid with 2-aminoethanol afforded crystals of the corresponding salts. The resulting crystalline products were characterised with the usual methods (proton nuclear magnetic resonance, infrared spectroscopy, elemental analysis) and their crystal structures were determined by means of single-crystal X-ray diffraction analysis. The crystal structures of the salts mentioned above usually contain rather complicated two dimensional networks of charge-assisted hydrogen bonds. With the aim of studying potentially more simple hydrogen-bonded structures, additional crystallisation experiments were conducted in systems of ferrocenecarboxylic acid and 2-(methylamino)ethanol or 2-(dimethylamino)ethanol. These experiments yielded simple salt of the former amine and adducts of salts of both bases with ferrocenecarboxylic acid in the ratio of 1:1. The...

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