National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Study of materials for the Li-ion batteries by electron microscopy
Hujňák, Jan ; Čudek, Pavel (referee) ; Kazda, Tomáš (advisor)
This work deals with problems of lithium-ion batteries. In the theoretical part are described electrochemical sources in general and their division. The main representatives of individual types of electrochemical sources are described in more detail. In the next part the thesis focuses specifically on lithium-ion accumulators, their history, electrochemical reactions taking place inside and materials of individual parts of which the accumulator consists. Next part focuses on electron microscopy and its division into scanning and transmission. Basic parts and the principle of operation are described. The practical part is focused on creating a small cell for examination under an electron microscope.
Smoothing device for FDM 3D prints
Dubský, Jan ; Čudek, Pavel (referee) ; Bayer, Robert (advisor)
This bachelor’s thesis deals with a design of a device that would smooth out 3D prints, made of various materials, using FDM 3D printers. It explains the principle of 3D printing and describes technologies used in 3D printing. In this work is an overview of materials used for 3D printing and of some selected organic solvents. It describes methods of vapour smoothing and aerosol smoothing that can be used for smoothing out of 3D prints surface. The vapour smoothing method was experimentally tested using these solvents: acetone, dichloromethane, chloroform and tetrahydrofuran. The aerosol smoothing method used a solution of acetone and dichloromethane in the ratio of 1:1. Both methods were tested on samples made of PLA, ABS, PETG and SBS. This paper describes the design of a device for smoothing of 3D prints with regard to the chemical compatibility of used construction materials and ease of use of the device.
Influence of working conditions on the results of EDS in ESEM
Pospíchal, David ; Čech, Ondřej (referee) ; Čudek, Pavel (advisor)
The bachelor thesis deals with energy dispersion spectroscopy and detection of characteristic X-rays in the field of environmental scanning electron microscope. The aim of the semester work is to compare the results of elemental microanalysis of samples under optimal conditions and to monitor changes of results, when changing working conditions, resp. nitrogen and water vapor pressure in the sample chamber of the scanning electron microscope Vega3 XMU with LaB6 cathode. TESCAN, a.s equipped with Xflash 6 | 10 spectrophotometer. Bruker
Analysis of active material for batteries by EDS
Vídeňský, Ondřej ; Jaššo, Kamil (referee) ; Čudek, Pavel (advisor)
This master thesis deals with analysis of battery mass using x-ray spectral microanalysis. For the measurement two scanning electron microscopes equipped with energy dispersive x-ray spectroscopes were used. Appropriate examples were prepaired by standard method. Then elemental analysis was performed with changing conditions of measurement. Two programs were used for spectrums evaluation and in the end the size of errors was observed for every conditions.
Study of the electrode materials for Li-Ion accumulators by electron microscopy
Kaplenko, Oleksii ; Čudek, Pavel (referee) ; Kazda, Tomáš (advisor)
The aim of this work is to describe the influence of temperature on the structure and chemical composition of electrode materials for Li-ion accumulators. Theoretical part of this thesis contains described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly Li-ion batteries. Considering various composition of Li-ion batteries, the next subchapters deeply analyzes the most used cathode (with an emphasis on the LiFePO4, LiMn1/3Ni1/3Co1/3O2) and anode materials (with an emphasis on the Li4Ti5O12). The next chapters describe the used analytical methods: electron microscopy, energy dispersion spectroscopy and thermomechanical analysis. The practical part is devoted to the description of the individual experiments and the achieved results.
Measure the impact of wireless technologies on TEM
Prokop, Martin ; Čudek, Pavel (referee) ; Polsterová, Helena (advisor)
The purpose of this diploma thesis is to research and compare available wireless communication technologies (frequency, modulation type, transmission speed and consumption). Describe transmission electron microscopes theory and deduce the most sensitive microscope parts to high frequency distortion. Investigate effect of wireless technology on CE standards and come up with, perform and evaluate the influence measurement of chosen technologies on base parameters of transmission electron microscope.
Comparison of microscopic diagnostic methods
Veselý, Jakub ; Tihlaříková, Eva (referee) ; Čudek, Pavel (advisor)
This thesis deals with the description and comparison of diagnostic methods, transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The introduction is a description of diagnostic methods. The following experimental section dealing with the diagnosis of ferritic chromium steel sample methods of scanning electron microscopy, atomic force microscopy, transmission electron microscopy and the evaluation and interpretation of measured results. The conclusion provides a comparison, the advantages and disadvantages of diagnostic methods.
Method for evaluation of signal level value in environmental SEM
Kršňák, Jiří ; Tihlaříková, Eva (referee) ; Čudek, Pavel (advisor)
This work deals with the evaluating of the signal level value from the sample in the environmental SEM. In work there were processed the comparison of the osciloscopic method for the evaluating of the signal level value in the environmental SEM, the method for the evaluating of the signal level from the grey level of the sample images and the method for the evaluating of the signal level from the osciloscop. There are described the advantages and disadvantages of the methods and procedures for processing the methods.
Diagnostic of semiconductor materials by EBIC method
Davidová, Lenka ; Máca, Josef (referee) ; Čudek, Pavel (advisor)
Master´s thesis is focused on diagnostics of semiconductor materials by EBIC method (measuring of currents induced beam), determination of the lifetime of minority carriers, or their diffusion length. The theoretical part is aimed at the principle of scanning electron microscopy, the characteristic properties of the microscope and the signals generated by the interaction of the primary electron beam with the sample. The thesis describes a structure of semiconducting silicon, band models, types of lattice defects and doped of semiconductor structures. After that it is described the theory of calculation of the diffusion length of minority carriers in semiconductors of type N and P. The aim of the experiment part of the thesis is to measure the properties of the semiconductor structure by EBIC and determination of diffusion length and lifetime of minority charge carriers based on the measured data The aim of the experiment part of the thesis is to measure the properties of the semiconductor structure by EBIC and determination of diffusion length and lifetime of minority charge carriers on the basis of the measured data.
Influence of working conditions on the detected signal by BSE detector in the scanning electron microscope Vega 3 XMU
Tkáčová, Tereza ; Chladil, Ladislav (referee) ; Čudek, Pavel (advisor)
This work is focused on investigating of influence of different working conditions in scanning electron microscope to signal detected by backscattered electron detector. In the theoretical part, there is a general description of scanning electron microscope, backscattered electrons issue and also definition of methods of signal to noise ratio evaluation. The practical part is focused on observation of suitable samples in a scanning electrone microscope.

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