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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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Diffussion measurement by NMR
Vanko, Filip ; Gescheidtová, Eva (referee) ; Bartušek, Karel (advisor)
In Bachelor thesis is described the principle of MRI, the physical foundations of the phenomenon of magnetic resonance imaging, quantum and macroscopic model. Followed by a description of the mechanisms of relaxation of magnetic resonance phenomenon. In the following sections describes the basis of diffusion, each sequence for measuring diffusion NMR methods and the method of three measurements, which was used in experimental measurements. Last chapter deals with the practical. The results of measurements are evaluated in conclusion.
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Electromagnetic interference and pacemakers
Kulík, Jindřich ; Richter, Miloslav (referee) ; Havlíková, Marie (advisor)
This thesis deals with electromagnetic compatibility of implantable electro-medical devices using in cardiology. The main aim of this thesis is detection of the resistance of implantable pacemakers (PM) and implantable cardioverter defibrillators (ICD) to the electromagnetic interference. In the first part of this thesis, a function of the heart, which is necessary for understanding of PM and ICD operation, is described. The function and construction of PM and ICD is detailed in the theoretical part as well. The next part is focused on the electromagnetic compatibility. The next part is description of the measurement method and the experimental arrangement used for practical experiments with electromagnetic resistance of PM and ICD.
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Measurement of gradient magnetic field decay in MR tomograph
Kubásek, Ondřej ; Kubásek, Radek (referee) ; Bartušek, Karel (advisor)
The objective of my thesis is to measure magnetic field gradient decay in an MR tomograph, process and evaluate the data measured and analyse the issue. The theoretical section focuses on the reasons for the gradient distortion which has a negative impact on NMR measuring techniques and it also describes options to eliminate the negative effects, focusing mainly on pre-emphasis filtration. It also lists methods of gradient magnetic field measuring. The practical section contains results of magnetic field decay measurements taken with the tomograph in the Institute of scientific instruments of the Academy of sciences in Brno using the method of instantaneous frequency with and without pre-emphasis compensation. The data are processed with MAREVISI and MATLAB programmes. MATLAB is used to develop a modern method of filtration to eliminate noise in useful signal leading to more accurate measurements of MR magnetic fields. This filtration uses a method of time-dependent variable thresholds and two-channel filter banks. MATLAB is also used to design a programme for approximation of the measured gradient magnetic field decay. The decay must be approximated in order to obtain time constants and the degree of exponential decay, which serve to set up the pre-emphasis compensation.
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Optimization of the experimental NQR spectrometer
Segiňák, Ján ; Král, Bohumil (referee) ; Steinbauer, Miloslav (advisor)
The thesis deals with the NQR spectroscopy, which is one of the modern non-destructive measurement and diagnostic methods for the characterization of various materials. It is using a quadrupole moment - a property of atomic nuclei of certain isotopes. A method of nuclear quadrupole resonance (NQR) is in principle very similar to nuclear magnetic resonance (NMR). Thesis in the theoretical part analyse the principles of NMR and NQR, describes the possible use of this method to detect for example explosives, drugs, and other chemicals. In the following chapters are analysed the key parameters of NQR spectrometer and the principle of the chosen measurement method. The practical part deals with the individual components of NQR spectrometer, the design of possible improvements and programming of the measuring sequence. In the final chapter are processed the measurements of the submitted samples.
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Creating a knowledge base for the diagnosing of diseases
Macháček, Daniel ; Steinerová, Kateřina (referee) ; Jirsík, Václav (advisor)
This bachelor thesis is focused on problematic of creation knowledge base. It is describing basics of expert systems, their function and possible usage in modern world. In result of this thesis is knowlenge base in web aplication NPS able to diagnose diseases of hematology-oncology and that is proving possibility for use in real life. Knowledge base was created in cooperation with experts in the medical field and contains real data.
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Surfactant organogels as delivery systems for medical and cosmetic oils
Koláčková, Petra ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
The aim of this thesis was to investigate the possible using of surfactant organogels in the cosmetic industry. Mainly, we focused on the ability of sugar surfactants to bind with medical (cosmetic) oil. With further heating, we observed transformation to the organogels. During the preparation of sugar surfactants, we decided to use the transesterification method. Another target was to verify functionality of this method and then proposed modifications to this process. Using Nuclear Magnetic Resonance, we checked the chemical structure of our sugar-based surfactants.
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Effect of catalystic system on the structure of E/P copolymers
Kolomazník, Vít ; Kratochvíla,, Jan (referee) ; CSc, Zdeněk Buráň, (advisor)
Thesis is focused on structural study of ethylene-propylene copolymers (E/P copolymers) produced by gas phase polymerization. Goal of work was to determine the effect of used catalysts on the distribution of ethylene units in the resulting material. Three E/P copolymers were prepared on commercial Ziegler Natta catalysts with diether or phthalate based internal donors. The copolymers were fractionated according crystallization ability and molar mass. Next, the mass content and the distribution of the ethylene units in the copolymer were determined in each fraction by nuclear magnetic resonance (NMR). Together with other structural analytical methods, phthalate internal donor has been found to produce ethylene blocks under certain conditions, while the diether ID lacks this ability.
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Geometry of protein moleculs
Novotný, Jan ; Maděránková, Denisa (referee) ; Škutková, Helena (advisor)
Objective of this work was to study the spatial arrangement of protein molecules, with their extraction, notations and variables used in the course descriptions. Prediction of protein structures is very important for determining the future function of proteins. Another objective was to create a function in MATLAB that will graphically represent the spatial arrangement of the backbone structure of the protein by form Ramachandran plot. Along with this function create another function to render the side-chains of amino acids and function to calculate the stereochemical quality. Finally, create a program for a complete assessment of the spatial arrangement of the protein molecules and calculating the stereochemical quality of and test program for protein structures from public databases RSCB PDB.
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Study of gel electrolytes properties by MR methods
Mrnka, Michal ; Gescheidtová, Eva (referee) ; Bartušek, Karel (advisor)
Theoretical part of the work deals with explanation of nuclear magnetic resonance phenomenon, relaxation processes in system of nuclear spins, basic techniques for measurement of relaxation times. There are described diffusion and techniques for diffusion coefficient measurement including method for suppressing the background gradient. Experimental part describes preparation of gel electrolytes samples and measurement of relaxation times. Sodium salt was used as a conductive agent. There is interpreted dependence of relaxation times on polymerization times and on concentration of conductive agent in gels.
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