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Analysis of biological significant substances
Maděránková, Denisa ; Rychtárik, Milan (referee) ; Roleček, Jiří (advisor)
Selected methods of Raman spectroscopy, like surface-enhanced Raman spectroscopy and single molecule Raman spectroscopy, are described in this diploma work. The basis of two methods for numerical modelling of optical properties of micro- and nanoparticles are prefaced. The methods are Discrete Dipole Approximation and Finite Difference Time Domain. Micro- and nanoparticles are used in surface enhanced Raman spectroscopy and other nanospectroscopic methods. Further, the main instrumentation needed for Raman spectroscopy is described. The first part of experimental section of this work is numerical modelling of photonic nanojet that occures behind dielectric microparticles. This phenomenon leads to a new technique of confocal microscopy with Raman spectra measuring. The second experimental section contains results of Raman spectra measurement with beta-carotene and surface-enhanced Raman spectra of beta-carotene in silver-sol solution.
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Critical infrastructure protection using distributed temperature sensing
Holcman, Jiří ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
This master thesis aims to show the possibility of practical use of an optical fiber as a distributed temperature sensor. The main goal is the possibility of protection of waste pipes (critical infrastructure) against leaks, fluid leaks, line disturbances, fires, freezing, etc. The first part describes the basic elements of the system for distributed temperature measurement using optical fiber such as optical fiber sensor, block diagram involvement and theoretical basis on which the measurement is based. The physical principle of temperature sensing using an optical fiber using Raman backscattering of light is explained, as well as Rayleigh and Brillouin scatterings, which, however, are not used in this thesis. Furthermore, the main advantages of DTS systems are presented, such as the possibility of detection over long distances, almost maintenance-free operation with a long service life and easy installation in practice. Next, some global DTS manufactures of equipment for the implementation of these distributed temperature measurement systems. To verify the main parameters, a reference measurement was designed and implemented. In the next part of the work is assembled a simple DTS system simulating the practical implementation of pipelines in laboratory conditions. The possibilities of measured quantities such as sensitivity to temperature changes, resolution and measurement accuracy were verified on this system. All these values were recorded, graphically represented and evaluated. The investigated quantities were clearly marked and described on the graphs of the results. At the end of the work, the results of measurements were clearly summarized and the possibilities of practical use for the protection of critical infrastructures were indicated.
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Distributed temperature sensor
Holík, Tomáš ; Čučka, Milan (referee) ; Münster, Petr (advisor)
Distributed temperature sensors are currently widely used. They are used for measuring temperature using optical fiber. DTS systems measure the temperature along the optical fiber. Optical fiber is used as a direct source of information, not as a carrier. That is, optical fiber is used as a sensor measuring the temperature. This work includes designs of the measuring system DTS using Raman scattering and Mach-Zehnder modulator in a single-mode fiber.
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Optical fiber as a distributed temperature sensor
Vošček, Jakub ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
The financial requirements between fiber optic sensors and conventional sensors are gradually declining, which, despite many advatages and wide range of applicationas, has slowed down the demand for these sensors. With the demand for fiber optic sensors also grow the requirements for the parameters of these sensors. This thesis deals with distributed temperature fiber optic sensors. Non--linear phenomen in optical fibers, such as Raman scattering is used for measuring with these sensors. This scatterin was used to obtain information about temperature, which effected the optical cable under the test.
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Optical Distributed Sensor Systems
Dorazin, David ; Münster, Petr (referee) ; Čučka, Milan (advisor)
This bachelors thesis solves possibilities of utilization optical fiber as a sensor. At the beginning the thesis desribes basic principle of ligh transmition in optical fiber, optical fiber and his linear and nonlinear properties. Second part of the thesis deals with sorting of distributed optical fiber sensors and describes each type of the sorted sensor due to principle which they work on. The Michelson interferometer is described and its modification in the form of the Fiber optic Michelson interferometer, which is designed and simulated in the VPIphotonics software. At the end of the thesis is performed measuring of vibrations by the Fiber optic Mach-Zehnder interferometer.
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HDO Raman spectrum
Šubr, Martin ; Štěpánek, Josef (advisor) ; Procházka, Marek (referee)
Title: HDO Raman spectrum Author: Martin Šubr Department: Institute of Physics of Charles University Supervisor: Prof. RNDr. Josef Štěpánek, CSc., Institute of Physics of Charles University Abstract: The main aim of this thesis is to determine the HDO Raman spectrum. This spectrum cannot be measured separately in its liquid form, but it is possible to obtain it by a specific mathematical processing of sets of measured spectra with different H/D ratios. In this work we measured Raman spectra of liquid water with different mole fractions of water and heavy water, which were evaluated by factor analysis. Except for well-known spectra of water and heavy water, spectrum of HDO was determined. For fitting of this spectrum and its analysis, model with equilibrium constant and linear correction of the spectral shape with respect to the relative ratio of D was used. Keywords: Raman scattering, water and heavy water, HDO, factor analysis
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Mechanical and Electrical Properties of Microcrystalline Silicon Thin Films
Vetushka, Aliaksei ; Fejfar, Antonín (advisor) ; Čech, Vladimír (referee) ; Sládek, Petr (referee)
Amorphous and nano- or micro- crystalline silicon thin films are intensively studied materials for photovoltaic applications. The films are used as intrinsic layer (absorber) in p-i-n solar cells. As opposed to crystalline silicon solar cells, the thin films contain about hundred times less silicon and can be deposited at much lower temperatures (typically around 200 0 C) which saves energy needed for production and makes it possible to use various low cost (even flexible) substrates. However, these films have a complex microstructure, which makes it difficult to measure and describe the electronic transport of the photogenerated carriers. Yet, the understanding of the structure and electronic properties of the material at nanoscale is essential on the way to improve the efficiency solar cells. One of the main aims of this work is the study of the structure and mechanical properties of the mixed phase silicon thin films of various thicknesses and structures. The key parameter of microcrystalline silicon is the crystallinity, i.e., the microcrys- talline volume fraction. It determines internal structure of the films which, in turn, decides about many other properties, including charge transport and mechanical sta- bility. Raman microspectroscopy is a fast and non-destructive method for probing the...
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Vibrational spectroscopy of pharmacologically important molecules: Study of L-DOPA and its deuterated derivatives
Spasovová, Monika ; Profant, Václav (advisor) ; Kaminský, Jakub (referee)
L-3,4-dihyroxyphenylalanine (L-DOPA, levodopa) is a gold standard treatment of Parkinson's disease. Lately, it has been found that some of its deuterated analogues exhibit higher potency in the treatment; thus, they could replace L-DOPA. The subject of this thesis was a study of L-DOPA and its deuterated derivatives by the means of vibrational spectroscopy (Raman, ROA, IR, and VCD) and a comparison of the experimental results to a quantum mechanical simulations of the spectra. ROA and VCD are chiroptical methods, thus they are suitable for measurement of chiral molecules amongst which L-DOPA indeed belongs. Thanks to the quantum chemistry calculations, which yielded spectra with a very good agreement with the experiment, we were able to assign experimental spectral features to individual vibrational modes of the L-DOPA. The use of chiroptical techniques (mainly ROA) enabled an assignment of an absolute configuration of double deuterated derivative of L-DOPA, α,β-D2-L-DOPA. It reviled that it occurs in a (S-α,S-β)-enantiomeric form.
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Optical fiber as a distributed temperature sensor
Vošček, Jakub ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
The financial requirements between fiber optic sensors and conventional sensors are gradually declining, which, despite many advatages and wide range of applicationas, has slowed down the demand for these sensors. With the demand for fiber optic sensors also grow the requirements for the parameters of these sensors. This thesis deals with distributed temperature fiber optic sensors. Non--linear phenomen in optical fibers, such as Raman scattering is used for measuring with these sensors. This scatterin was used to obtain information about temperature, which effected the optical cable under the test.
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Critical infrastructure protection using distributed temperature sensing
Holcman, Jiří ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
This master thesis aims to show the possibility of practical use of an optical fiber as a distributed temperature sensor. The main goal is the possibility of protection of waste pipes (critical infrastructure) against leaks, fluid leaks, line disturbances, fires, freezing, etc. The first part describes the basic elements of the system for distributed temperature measurement using optical fiber such as optical fiber sensor, block diagram involvement and theoretical basis on which the measurement is based. The physical principle of temperature sensing using an optical fiber using Raman backscattering of light is explained, as well as Rayleigh and Brillouin scatterings, which, however, are not used in this thesis. Furthermore, the main advantages of DTS systems are presented, such as the possibility of detection over long distances, almost maintenance-free operation with a long service life and easy installation in practice. Next, some global DTS manufactures of equipment for the implementation of these distributed temperature measurement systems. To verify the main parameters, a reference measurement was designed and implemented. In the next part of the work is assembled a simple DTS system simulating the practical implementation of pipelines in laboratory conditions. The possibilities of measured quantities such as sensitivity to temperature changes, resolution and measurement accuracy were verified on this system. All these values were recorded, graphically represented and evaluated. The investigated quantities were clearly marked and described on the graphs of the results. At the end of the work, the results of measurements were clearly summarized and the possibilities of practical use for the protection of critical infrastructures were indicated.
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