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SMV-2012-04: Investigation of optical frequency refences for lasers stabilization in visible spectral range
Lazar, Josef ; Hrabina, Jan
The main aim of this work was oriented towards design and realization of optical frequency references for stabilization of frequency-doubled Nd:YAG lasers with 532 nm wavelength. Research included investigation of absorption references (cells filled with absorption media) technology. The realized cells will serve as references for precise frequency stabilization of laser sources intended for primary metrology of length. Evaluation measurement of realized cells performed by laser induced fluorescence method resulted in reached Stern-Volmer coefficients K0<1 Pa which means the most avaiable purity of absorption media with expected frequency offset of realized laser standard below 1 kHz. Expected reachable relative frequency stability is at level of 3e-14 for integration time of 100 s.
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Raman tweezers in microfluidic systems for automatic analysis and sorting of living cells
Pilát, Zdeněk
We have devised an automatic analytical and sorting system combining optical trapping with Raman spectroscopy in microfluidic environment, together with computerized real time image analysis, spectra processing and micromanipulation. This device serves to identify and sort biological objects, such as living cells of various prokaryotic and eukaryotic organisms based on their Raman spectral properties. This approach allowed us to collect information about the chemical composition of the objects, such as the presence and composition of lipids, proteins, or nucleic acids without using artificial chemical probes such as fluorescent markers. The non-destructive and non-contact nature of this optical analysis and manipulation allowed us to separate individual living cells of our interest in a sterile environment and provided the possibility to cultivate the selected cells for further experiments. The special microfluidic chip uses gravity to move the cells across the sorting area. Our system uses dedicated software to achieve fully automated spectral analysis and sorting. The devised system is a robust and universal platform for non-contact sorting of microobjects based on their chemical properties. It could find its use in many medical, biotechnological, and biological applications.
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Characterization of by-products from the combustion of solid fuels with SEM/EDS and micro-Raman spectroscopy
Šašek, Petr ; Viani, Alberto ; Mácová, Petra ; Pérez-Estébanez, Marta ; Černá, M.
The solid residues from the combustion currently represent a problem that needs to be addressed. Quality products from combustion of solid biomass and coal is significantly different, may contain heavy metals and therefore their application difficult. Total used 4 samples of solid residues from the combustion of solid fuels, where two samples consisted of ash from the combustion of coal, respectively lignite and two samples were made with ash from the combustion of biomass, namely straw and hay. The microscopic analysis was used a scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) and Micro Raman. The qualitative analysis was used in addition X-ray diffraction. Within the microscopic analyses were tested superficially different types of materials.
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Protein Control Over Carotenoid Spectroscopy and Functions
ŠLOUF, Václav
The photophysics of pigments is influenced, to an extent depending on its structure, by the properties of the environment. Proteins represent a very specific environment at least in two aspects: i) they are native to most of the pigments in living systems; ii) they facilitate modifications of pigment configuration, leading to changes not only in its spectroscopic properties, but also in its functional abilities. In studies presented in this thesis, femtosecond pump-probe spectroscopy was used to study predominantly the photosynthetic antenna complexes of bacteria and algae. Based on spectroscopic evidence, the structural modifications of pigments imposed by the protein were deduced or hypothesized, together with their functional relevance.
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Thin Functional Films of TiO2 Nanoparticles
Morozová, Magdalena ; Klusoň, Petr ; Hejda, S. ; Kment, Štěpán ; Šolcová, Olga
Magnetron Sputtering and the Modulated Hollow Cathode Plasma Jet Sputtering. As chemical method the sol-gel process carried out in the templating environment as dip-coating and piezo-jet printing was employed. The produced films differed in many structural characteristics and also in their photoelectrochemical behaviour, as the primary sought function. The produced layers were described by means of atomic force microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, Raman spectroscopy, ellipsometry and profilometry. Then the films were used as electrodes in photoelectrochemical experiments.
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