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Susceptibility weighted magnetic resonance imaging (SWI)
Bačovský, Jaromír ; Bartušek, Karel (referee) ; Starčuk, Zenon (advisor)
Susceptibility weighted magnetic resonance imaging (SWI) seems to be a very promising method usable in the diagnosis of a number of clinical and biomedical applications. Difusse axonal injuries and neurodegenerative diseases to name a few. The goal of my bachelor's thesis was to study the principal methods of magnetic resonance imaging with particular emphasis on susceptibility weighted imaging. Then use this theoretical knowledge for practical implementation of the SWI method to 4,7T/200mm NMR system located at Institute of Scientific Instruments of the ASCR, v.v.i. It was necessary to create an image calculated software, which is capable of enhancing contrast caused by magnetic susceptibility differences as they manifest themselves in local phase changes between tissues. Few basic problems had to be solved. The phase image was filtered by a high pass filter, a Phase Mask was created from adjusted image, which is generated from phase unwrapped image. To varify the SWI method, samples were designed, which have the desired magnetic properties. During the initial phase of experimenting, hen's eggs were used and then citrus fruits with nanoiron, CaCl2, Zn and AgCl. We investigated basic parametres and settings of the MRI measurements that affect final susceptibility weighted image.
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Optimization of method for susceptibility measurement
Jeništa, Petr ; Marcoň, Petr (referee) ; Bartušek, Karel (advisor)
The aim of this thesis is measure the specimens placed in field of MR tomograph, the measured data to evaluace the process and measurement errors. The theoretical part is focused on describing basic parameters of magnetic field, commissioning some older methods of measurement and design methods for the measurement of samples not issuing MR signal. There is performed modeling for the proposed Metod and the 1D, 2D and 3D environments using COMSOL Multiphysics. The practical part is the measurements samples in the tomograph the Institute of Scientific Instruments Academy of Science in Brno. The measured data are processed in Marevisi and Matlab programs. The MATLAB program is written for processing, analysis and data evaluation, after which it is possible to determine the value of the magnetic susceptibility of the selected samples. In conclusion of the work is the quantification accuracy of measurements.
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Use of rock mass classifications for rock fall susceptibility analysis in the conditions of the Bohemian Massif
Racek, Jonáš ; Blahůt, Jan (advisor) ; Petružálek, Matěj (referee)
This thesis deals with rock mass classification systems. The aim of the thesis is to describe and compare selected systems and evaluate their possible use in the Bohemian Massif for assessing the stability of the rock slopes in relation to their susceptibility to rock falls. A part of the thesis deals with rock falls and basic mechanical characteristics of a rock mass. Further on, the thesis describes selected classification systems, specifically RQD, RSR, RMR, SMR, Q-system, Q-slope, GSI, RSR-PR and QTS. These systems were then used for evaluation of stability of rock slopes on three geologically different locations of the Bohemian Massif. information from measurement in field and processing of measured data was used for assessing for possible use of each classification system.
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Use of rock mass classifications for rock fall susceptibility analysis in the conditions of the Bohemian Massif
Racek, Jonáš ; Blahůt, Jan (advisor) ; Petružálek, Matěj (referee)
This thesis deals with rock mass classification systems. The aim of the thesis is to describe and compare selected systems and evaluate their possible use in the Bohemian Massif for assessing the stability of the rock slopes in relation to their susceptibility to rock falls. A part of the thesis deals with rock falls and basic mechanical characteristics of a rock mass. Further on, the thesis describes selected classification systems, specifically RQD, RSR, RMR, SMR, Q-system, Q-slope, GSI, RSR-PR and QTS. These systems were then used for evaluation of stability of rock slopes on three geologically different locations of the Bohemian Massif. information from measurement in field and processing of measured data was used for assessing for possible use of each classification system.
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Landslide susceptibility analysis of Czechia
Racek, Ondřej ; Blahůt, Jan (advisor) ; Klimeš, Jan (referee)
In geosciences modelling is rather quickly developing discipline. Statistical modelling of landslide susceptibility is relatively more traditional approach. Nevertheless, more complicated statistical methods are being developed and applied on larger areas. This development is caused especially by increasing computational capacity and software. This diploma thesis summarises existing statistical landslide susceptibility modelling approaches. In the following part, several landslide susceptibility models were created for the area of Czechia. These models were created using logistic regression, naive Bayes and artificial neural network (ANN). Additionally, two more models were created using expert driven approach. All models were made using thirteen conditioning factors, i.e.elevation, slope, engineering geological regions, climatic areas, mean annual precipitation, topographic wetness index (TWI), aspect, orogenetic class, distance from confirmed fault, distance from watercourse, internal relief, land cover and slope shape. Models driven by statistical approach were created using Orange software. Landslide inventories that were used for construction of all models are based on two databases: "Registr svahových nestabilit" and "Registr sesuvů-Geofond". Using validation by SRC, PRC and ROC curves...
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Genes participating in response to Leishmania major revealed by targeted mutation.
Ezrová, Zuzana ; Lipoldová, Marie (advisor) ; Krulová, Magdaléna (referee)
Leishmania major is an intracellular parasite which often successfully multiplies and disseminates in a body of the host thanks to strategies that help it to escape the components of immune system of the host organism. Thus, the parasites evoke an impairment of regulatory pathways that in physiological conditions lead to an expression of genes involved in a response to L. major and its efficient elimination. Gene targeted deletion, also called gene knock-out, can result in phenotypic alteration and associated enhanced susceptibility or resistance of the host. Although such detected genes do not have to signify their variability in population and hence they may not be responsible for the worsened outcome of leishmaniasis of some people necessarily, studies in which they are analysed and general knowledge being also a subject of this thesis help us together with techniques of forward genetics to reveal the biochemical pathways during the infection and their elements that influence the outcome of the disease and might be useful for researches of new medicine drugs or gene therapy.
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Low temperature part of penetration depth in conventional and unconventional superconductors
Baničová, Lucia ; Janů, Zdeněk (advisor) ; Havela, Ladislav (referee)
In the present work I study temperature dependence of magnetic penetration depth in superconductors which allows us to determine the symetry of the order parameter, important for theoretical models. In conventional superconductors we talk about s-symetry. Energy gap is isotropic and as a consequence of this fact penetration depth grows exponencialy with the temperature. On the other hand, in unconventional superconductors with d-symetry we find the power dependence on the temperature. Anyway the exponent depends on impurities and structure of the material and the influence of these parametrs is not completely clear at the moment.
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Temperature dependence of susceptibility of thin Pb films
Truněček, Otakar ; Janů, Zdeněk (advisor) ; Vašek, Petr (referee)
This master thesis is focused on temperature dependence of magnetization curves and susceptibility of thin films of type-I superconductor. A model for susceptibility of type-I superconductor in intermediate state is presented. This model is compared with experimental data yielding temperature dependence of critical magnetic field of superconductor. Furthermore it is shown that sufficiently thin film of superconductor which is type-I in bulk can exhibit type-II behaviour in perpendicular magnetic field. Susceptibility measured on such a film is therefore compared to susceptibility calculated for Bean model for type-I superconductors.
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Optimization of method for susceptibility measurement
Jeništa, Petr ; Marcoň, Petr (referee) ; Bartušek, Karel (advisor)
The aim of this thesis is measure the specimens placed in field of MR tomograph, the measured data to evaluace the process and measurement errors. The theoretical part is focused on describing basic parameters of magnetic field, commissioning some older methods of measurement and design methods for the measurement of samples not issuing MR signal. There is performed modeling for the proposed Metod and the 1D, 2D and 3D environments using COMSOL Multiphysics. The practical part is the measurements samples in the tomograph the Institute of Scientific Instruments Academy of Science in Brno. The measured data are processed in Marevisi and Matlab programs. The MATLAB program is written for processing, analysis and data evaluation, after which it is possible to determine the value of the magnetic susceptibility of the selected samples. In conclusion of the work is the quantification accuracy of measurements.
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Susceptibility weighted magnetic resonance imaging (SWI)
Bačovský, Jaromír ; Bartušek, Karel (referee) ; Starčuk, Zenon (advisor)
Susceptibility weighted magnetic resonance imaging (SWI) seems to be a very promising method usable in the diagnosis of a number of clinical and biomedical applications. Difusse axonal injuries and neurodegenerative diseases to name a few. The goal of my bachelor's thesis was to study the principal methods of magnetic resonance imaging with particular emphasis on susceptibility weighted imaging. Then use this theoretical knowledge for practical implementation of the SWI method to 4,7T/200mm NMR system located at Institute of Scientific Instruments of the ASCR, v.v.i. It was necessary to create an image calculated software, which is capable of enhancing contrast caused by magnetic susceptibility differences as they manifest themselves in local phase changes between tissues. Few basic problems had to be solved. The phase image was filtered by a high pass filter, a Phase Mask was created from adjusted image, which is generated from phase unwrapped image. To varify the SWI method, samples were designed, which have the desired magnetic properties. During the initial phase of experimenting, hen's eggs were used and then citrus fruits with nanoiron, CaCl2, Zn and AgCl. We investigated basic parametres and settings of the MRI measurements that affect final susceptibility weighted image.
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