|
|
Change of magnetic susceptibility during the germination of plants
Sedlář, Petr ; Fiala, Pavel (referee) ; Vlachová Hutová, Eliška (advisor)
The work examines the changes in the magnetic susceptibility during the early germination of the somatic embryo (RSE) of the Norway spruce. Susceptibility is in the physically view the property, which can be used to determine a variety of parameters and properties of the measured objects. The aim of this work was to create a automatic to evaluate the susceptibility of the tissue RSE and take measurements to prove or disprove the contrary of the accuracy of this assessment. This work contains the results obtained by modeling a script in Matlab, in which can be shown the correctness of the theoretical concepts.
|
|
|
Metal detector for industrial use
Stehno, Rostislav ; Friedl, Martin (referee) ; Szabó, Zoltán (advisor)
The goal of this project is explore and study the ways of metal detecting and create a metal detector for industrial use. During a project development, the device size and user easy interface were the basic requirement. As a visual device was chosen LCD touch display, which is very important as a user-friendly interface. For math calculations and right function of device will be implemented microcontroller from Atmel corporation. As a data storage will be used a flash memory with 16MB of size. When the device were inventing, a lot of methods were studied and the impulse detect method were chosen which is the most perspective way of metal detecting. Device will communicate with PC trough a USB port. The device will have a battery which allows device to run for a few hours. The prototype of PCB were developed. Few mistakes has been discovered, while the device were constructed, but they were solved successfully.
|
|
|
Metal detector for industrial use
Stehno, Rostislav ; Hrabina, Jan (referee) ; Szabó, Zoltán (advisor)
The goal of this project is explore and study the ways of metal detecting and create a metal detector for industrial use. When the device were inventing, a lot of methods were studied and the impulse detect method were chosen as the most perspective way of metal detecting, thanks to a huge electronics parts possibilities. After experiences with preceding device was necessary to redesign it. Main target of this thesis is to increase the computing power of detector. For this purpose will device need a new microcontroller. Device will communicate with PC trough a USB port. The device will have a battery which allows device to run for a few hours. Processing of measured data will be make even with DFT which will lead to better analyze of mass and type of conductor under device.
|
|
|
Numericalanalysis and measurement of the magnetic charakteristics in inhomogeneous materials by the NMR technics
Mrázek, Jiří ; Bartušek, Karel (referee) ; Fiala, Pavel (advisor)
This bachelor thesis is concerned in magnetic susceptibility of specific object (glass cube, with four sticks in the centre). In the first part determining of magnetic susceptibility of object was carried out. Measuring was conducted on tomograph of ÚPT AV ČR. Method of gradient echo, which allows magnetic susceptibility determining of non-magnetic materials, was used. Distribution of magnetic field within the object was acquired (object was measured with and without sticks), the change of magnetic field (between object with and without stick) was subsequently determined. In the second part, magnetic field simulation of the same object in the ANSYS software was performed. Calculation was conducted on 3D model by the finite element analysis. Distribution of magnetic field of object was acquired as a result of simulation. Results from simulation were compared with experimental findings.
|
|
|
Analysis of Selected Artefacts in Diffusion-Based Magnetic Resonance Measurements
Marcoň, Petr ; Král, Bohumil (referee) ; Frollo, Ivan (referee) ; Bartušek, Karel (advisor)
The presented dissertation thesis analyses artefacts in diffusion-weighted images. In medical practice, the artefacts can impede the diagnostics of pathological tissues and, therefore, need to be eliminated. As the first step within the thesis, an analysis of the most frequent artefacts in diffusion-weighted images is performed, and the hitherto known approaches to artefact elimination are described. In order to facilitate the reduction of artefacts caused by the inhomogeneity of the static magnetic field and induced by eddy currents, a novel three-measurement method is shown. This technique will find application especially in measuring the diffusion coefficient of isotropic materials. At this point, it is important to note that a significant and commonly found problem is the magnetic susceptibility artefact; different magnetic susceptibility values at the boundary between two materials can cause magnetic field inhomogeneities and even complete loss of the signal. Therefore, we designed a novel method for the measurement of magnetic susceptibility in various samples of magnetically incompatible materials, which do not produce any MR signal. The technique was experimentally verified using a set of differently shaped diamagnetic and paramagnetic samples. In addition to the magnetic susceptibility problem, the thesis presents artefacts such as noise, motion-induced items, hardware limitations, chemical shift, and the dependence of the diffusion coefficient on the temperature. To enable precise measurement of the diffusion coefficient, we proposed a thermal system; in the experiment, it was determined that when the measurement error does not exceed 5%, the temperature change should not be higher than 0,1 °C. In the final sections of the thesis, practical application examples involving the designed methods are shown.
|
|
|
Parameter optimization of MR sequences for magnetic susceptibility measurement
Pinkava, Jan ; Bartušek, Karel (referee) ; Steinbauer, Miloslav (advisor)
The Bachelor thesis deals with measuring magnetic susceptibility by means of nuclear magnetic resonance. Magnetic field is affected and deformed by various materials. The range and the shape of the deformation is caused by susceptibility. The thesis contains a 2D numerical model of a sample in a magnetic field 4.7 T. The results are compared with values obtained by a tomographic measurement. The second part of the thesis contains a 3D numerical model of diamagnetic and paramagnetic material. Moreover, a comparison with values measured in reality is drawn.
|
|
|
Numerical modelling and measurement of the magnetic susceptibility in inhomogeneous materials by the NMR technics
Julínek, Michal ; Steinbauer, Miloslav (referee) ; Fiala, Pavel (advisor)
This bachelor work is concerned in magnetic susceptibility of specific object (glass cube filled with clay, with glass sphere in the centre). In the first part determining of magnetic susceptibility of object was carried out. Measuring was conducted on tomograph of ÚPT AV ČR. Method of gradient echo, which allows magnetic susceptibility determining of non-magnetic materials, was used. Distribution of magnetic field within the object was acquired (object was measured with and without sphere), the change of magnetic field (between object with and without sphere) was subsequently determined. In the second part, magnetic field simulation of the same object in the ANSYS software was performed. Calculation was conducted on 3D model by the finite element analysis. Distribution of magnetic field of object was acquired as a result of simulation. Results from simulation were compared with experimental findings.
|
|
|
Material analysis of natural stone - sedimentary and crystalline limestone ("marble") - exact laboratory methods as a tool to determine the source area
Přikryl, Richard ; Šťastná, Aneta ; Kozlovcev, Petr ; Přikrylová, Jiřina ; Zamrazilová, Lenka
Metodika se zabývá hlavními postupy a analytickými rozbory, které lze využít k petrografickému a geochemickému popisu sedimentárních vápenců a mramorů, který poté slouží k určování jejich provenience. V metodice je diskutován rozsah použití jednotlivých metod pro popis sedimentárních a krystalických vápenců („mramorů“) a současné možnosti jejich petrografické klasifikace. Předkládaná metodika je určena pro oblast památkové péče, která využívá výsledků materiálových rozborů objektů kulturního dědictví – sochařských výtvarných děl, architektonických prvků a staveb, zhotovených ze sedimentárního nebo krystalického vápence. Výsledky, dosažené pomocí postupů, navržených v této metodice by měly přispět: (1) ke zpřesnění znalostí o materiálu; (2) ke sjednocení postupů, používaných při klasifikaci vápenců a mramorů; (3) k nalezení zdrojové lokality či alespoň oblasti, z níž byl přírodní kámen (vápenec a mramor) odebírán; (4) k hledání vhodného náhradního typu vápence nebo mramoru při nutnosti výměny; (5) k poznání vhodných postupů při restaurování objektů ze sedimentárního nebo krystalické vápence. Oblast využití této metodiky je tedy při předrestaurátorských materiálových průzkumech památek, na nichž byl použit příslušný typ přírodního kamene, tedy vápenec nebo mramor. Předložená metodika je určena širšímu okruhu specialistů, kteří se podílejí na předrestaurátorských materiálových průzkumech památek, nebo rozbor zadávají, či výsledky průzkumu potřebují pro volbu vhodné strategie restaurování. Metodika byla certifikována dne 28. 5. 2015, Osvědčení č. 34(č.j. MK 3363/2015 OVV; sp. zn. MK-S 115/2015 OVV).
Fulltext:  PDF; PDF
|
|
|
Využití geopedologických metod ve výzkumu vývoje krajiny
Olišarová, Lucie
This thesis describes laboratory and terraneous methods focused on the themes of landscape changes. It describes the basic principles of methods, such as a description of the stratigraphy, micromorphology, magnetic susceptibility, phosphate analysis and more. The thesis also discusses the strengths and the weaknesses methods which are mentioned above. The conclusion is devoted to a particular research in the area Česká Bělá, where are identified the remains in the country after the extraction of polymetallic ores in the early Middle Ages. There are still visible some remains of mining till today and there already have been done two archaeological excavations since 2007.
|
|
|
Využití magnetické susceptibility ve výzkumu kvartérních sedimentů
Gottvald, Zdeněk
This thesis deals with rock magnetism, paleomagnetism and environmental magnetism. It also gives a complex overview of this methods and presents their practical application and discusses the advantages and disadvantages of using these methods in research. In the first part of the paper the basic theory of magnetism is described. The second section is focused on detailed techniques of magnetic susceptibility measuring using professional laboratory equipment. For analysis were used specimens of quaternary sediments extracted in Moravský Kras. Particulary: the north side of cave Kůlna, cave Výpustek and in valley Křitinský potok. In conclusion the recorded values of magnetic susceptibility are compared with soil deposition. The thesis may be used as a data source for subsequent advanced analysis.
|
guest ::
