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Acquisition and Detection Geometry of the CT X-ray Imaging Process
Rusz, Jakub ; Harabiš, Vratislav (referee) ; Drastich, Aleš (advisor)
The basic components of acquisition and detection geometry of a 3rd generation single slice CT scanner are described here. Then the high contrast spatial resolution of the imaging process is explained and what effects does the setting of acquisition and detection geometry changes in the limiting high contrast spatial resolution. At the end a laboratory exercise and a simulator is presented, which will show and explain these effects.
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Properties of ultrasound probes
Rusina, Michal ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.
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Noncontact temperature measurements using luminescent materials
Jedlička, Jindřich ; Nebojsa, Alois (referee) ; Ligmajer, Filip (advisor)
This diploma thesis deals with noncontact temperature measurement using luminescent materials. In the theoretical part of the thesis, luminescent materials were selected on the basis of a literature review with respect to sensitivity and operating temperature range. In the experimental part of the thesis, photoluminescence of CdSe/ZnS and GaAs quantum dots for various temperatures was measured and the relative change of luminescence parameters such as emission peak position, intensity, intensity ratio of two emission peaks, and lifetime of luminescence were determined from the measurements in agreement with expectations according to the literature. Achieving high spatial resolution would be made possible by measuring cathodoluminescence, where the luminescence spectra are obtained with an order of magnitude higher spatial resolution. These measurements and the influence of electron beam on the luminescence quality of selected materials will be subject of further experimental study.
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Spatially- and time-resolved laser spectroscopy
Kuchařík, Jiří ; Němec, Petr (advisor) ; Preclíková, Jana (referee)
Speed is one of the most important characteristics of the majority of electro- nic and optoelectronic components. Ultrafast laser spectroscopy is therefore a very effective tool for studying the properties of materials suitable for their pro- duction. However, for more detailed information it is also necessary to achieve a high spatial resolution. In this bachelor thesis we deal with several experimental approaches which allow us to achieve a high spatial resolution in time-resolved experiments. In particular, we describe experimental setups using microscope ob- jectives and we also mention the use of transient grating technique. Furthermore, we present the results of our measurement of a time length of ultrashort laser pulses which are generated by the pulse laser Mai Tai HP and their expansion due to propagation through microscope objectives. 1
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High resolution region of interest X-Ray tomography
Kumpová, Ivana ; Vopálenský, Michal
The method of X-ray micro-tomography is increasingly used in the research of material characteristics and fracture behavior of building materials. It brings promising results in the field of three-dimensional observation and quantification of microstructure elements, including fracture objects. However, with the standard approach to the tomographic data acquisition, the achievable resolution is severely limited by the size of the examined object resulting in a reduction or even complete loss of useful information regarding, for example, the shape and size of the fracture process zone. For this reason, the possibilities of tomographic targetting of the region of interest with a higher achievable resolution than the usual limit of the tomographic systems have been tested in this work.
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Noncontact temperature measurements using luminescent materials
Jedlička, Jindřich ; Nebojsa, Alois (referee) ; Ligmajer, Filip (advisor)
This diploma thesis deals with noncontact temperature measurement using luminescent materials. In the theoretical part of the thesis, luminescent materials were selected on the basis of a literature review with respect to sensitivity and operating temperature range. In the experimental part of the thesis, photoluminescence of CdSe/ZnS and GaAs quantum dots for various temperatures was measured and the relative change of luminescence parameters such as emission peak position, intensity, intensity ratio of two emission peaks, and lifetime of luminescence were determined from the measurements in agreement with expectations according to the literature. Achieving high spatial resolution would be made possible by measuring cathodoluminescence, where the luminescence spectra are obtained with an order of magnitude higher spatial resolution. These measurements and the influence of electron beam on the luminescence quality of selected materials will be subject of further experimental study.
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|
|
Spatially- and time-resolved laser spectroscopy
Kuchařík, Jiří ; Němec, Petr (advisor) ; Preclíková, Jana (referee)
Speed is one of the most important characteristics of the majority of electro- nic and optoelectronic components. Ultrafast laser spectroscopy is therefore a very effective tool for studying the properties of materials suitable for their pro- duction. However, for more detailed information it is also necessary to achieve a high spatial resolution. In this bachelor thesis we deal with several experimental approaches which allow us to achieve a high spatial resolution in time-resolved experiments. In particular, we describe experimental setups using microscope ob- jectives and we also mention the use of transient grating technique. Furthermore, we present the results of our measurement of a time length of ultrashort laser pulses which are generated by the pulse laser Mai Tai HP and their expansion due to propagation through microscope objectives. 1
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|
|
Acquisition and Detection Geometry of the CT X-ray Imaging Process
Rusz, Jakub ; Harabiš, Vratislav (referee) ; Drastich, Aleš (advisor)
The basic components of acquisition and detection geometry of a 3rd generation single slice CT scanner are described here. Then the high contrast spatial resolution of the imaging process is explained and what effects does the setting of acquisition and detection geometry changes in the limiting high contrast spatial resolution. At the end a laboratory exercise and a simulator is presented, which will show and explain these effects.
|
|
|
Properties of ultrasound probes
Rusina, Michal ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.
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Properties of Ultrasound Probes
Rusina, M.
This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.
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