National Repository of Grey Literature 30 records found  previous11 - 20next  jump to record: Search took 0.00 seconds. 
Radioactive measurement with geolocation record
Bali-Jenčíková, Kateřina ; Janoušek, Oto (referee) ; Sekora, Jiří (advisor)
This diploma thesis deals with radioactivity research, types of radioactive radiation and radiation detection. There are described types of ionization radiation detectors. The diploma thesis contains the description and principle of the GPS system function. The content is also a proposal with the subsequent realization of a detection device allowing the recording of geolocation. The resulting device is fully mobile with battery status indication. The results are recorded on the SD card.
Lighting LED module for contactless measurement of physiological parameters
Byrtus, David ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This thesis describes the design of the illumination LED module for contactless measurement of basic physiological parameters. Contactless methods is based on the fotopletysmografických methods. The acquisition parameters used video camera for monitoring body part of the patient. Designed lighting LED module is used to enhance the optical signal with respect to quantum efficiency of the camera used. The acquired video sequences are then programmatically processed, analyzed, and the result is an estimate of the measured parameter.
Measurement and analysis of the detector preamplifier
Temel, Aleš ; republic, David Novák - FEI Czech (referee) ; Klusáček, Stanislav (advisor)
This paper investigates noise characteristics of detector preamplifier in electron scanning microscopes. Various preamplifiers are measured and the lowest noise level amplifier with good level of speed is used. Further measurement of individual levels of amplifier is done and proposed the most suitable way how to achieve the total amplification. By detailed measuring of amplifier structure are found all unpleasant factors that affect the image quality. On the basis of these dates amplifier hardware is adjusted, software solutions to improve image quality designed and model control implemented, which directly controls active elements of preamplifier so that noise for given amplification was the lowest and reached required amplification.
Comparison of the imaging capabilities of the transmission and scanning electron microscope
Maňka, Tadeáš ; Šamořil, Tomáš (referee) ; Zlámal, Jakub (advisor)
The aim of this work is to compare the imaging capabilities of the transmission and scanning electron microscope. The theoretical part describes the construction and the principle of each type of microscope. There is a list of the signal detectors, and the principle of imaging is described. The samples and their preparation are described. The practical part is aimed to imaging possibilities of both microscopes. A standard calibration samples were used for comparison. The advantages and disadvantages of both microscopes were discussed.
SMV-2015-20: Detection mechanism analysis in Teneo microscope
Radlička, Tomáš
A new method for calculation of material contrast in Teneo microscope was proposed and implemented. The method allows finding optimal system parameters setting for given set of materials. The used approach combines calculation of the primary beam properties, ray-tracing of high number of signal electrons (acceptation diagrams) and Monte - Carlo simulations. The three of standard usecases were described by this approach and optimal setting of free parameters was found to reach the maximal material contrast. The proposed method was experimentally tested which offered important feedback for future development. We have also implemented a method for simulation of the topographic contrast using line-scan through the non-trivial geometrical structure. The method was successfully experimentally verified. The development of the set of scripts in high-level dynamic programing language Julia was integral part of the project. It will simplify application of results.
Detekce signálu v rastrovacím elektronovém mikroskopu pomocí detektorů sekundárních elektronů
Konvalina, Ivo ; Hovorka, Miloš ; Dvořáková, Marie ; Müllerová, Ilona
The collection of secondary electrons (SE) was studied for microscopes where the magnetic field penetrates to the specimen surface and for the arrangement with the specimen region free of magnetic field. Collection efficiency of secondary electron detectors varies with their energy and angular sensitivity connected with electrostatic and magnetic field distribution in the specimen region which influences the contrast of SE images. The trajectories of SE with regard to their energy, angular distributions are simulated and secondary electron detectors compared on the basis of calculated collection efficiency. For the verification of the simulated data the standard resolution-testing specimen with Au particles on a carbon substrate was used.
Imaging of the voltage contrast in environmental SEM
Romanovský, Vladimír ; Autrata, Rudolf
Current methodology of imaging in the scanning electron microscopy is based on the detection of signal electrons that carry topografic and materialcontrast of specimens under study. Electronic devices can be observed because in their standard working mode voltage differences on component surfaces are visualized by means of the voltage contrast. This contrast can be acquired in nearly any commercially available scanning electron microscopeby detection and subsequent analysis of secondary electrons.

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