Creating 3D Printer Assembly Process and its Introduction into Education

Import 23/07/2015Bakalářská práce se zabývá vytvořením montážního postupu pro sestavení 3D tiskárny. V úvodní části je vysvětlen pojem aditivní technologie a následně jsou rozepsány jednotlivé metody této technologie, kde u každé je rozepsán princip, na jakém fungují. V další části je uveden podrobný montážní postup konkrétní 3D tiskárny společně s návrhem využití ve výuce.Bachelor thesis is dealing with designing 3D printer assembly process. In the introductory part the term additive technology is explained and subsequently each method of this technology is described in detail, including the description of the principle which it is based on. In the following part there is the particular 3D printer assembly process introduced thoroughly simultaneously with its introduction into education.346 - Katedra obrábění, montáže a strojírenské metrologievýborn

Replacement of the Stacking Unit of Stamping Line Used for Cutting Stacking

Import 23/08/2017Diplomová práce se zabývá vyhodnocením stávajícího stavu stohovacího zařízení ocelových přístřihů nástřihové linky. V úvodní, tedy teoretické části, je popsán princip výroby ocelových kol, funkce nástřihové linky a stohovacího zařízení společně s výhodami a nevýhodami současného zařízení. V další části diplomové práce jsou rozepsány možné varianty dalšího postupu řešení společně s výsledným řešením. Cílem této diplomové práce je navrhnout plně funkční úsek nástřihové linky, který bude jednoduchý pro následnou údržbu a také v co největší míře standardizovaný vůči ostatním úsekům linek v rámci společnosti.This master thesis is focused on evaluating of the current conditions of stacking units of stamping line used for a cutting stacking. In the introductory, the theoretical part, the principle of steel wheels production, the function of a stamping line and stacking device together with advantages and disadvantages of the current equipment are described. In the next part of this master thesis possible alternatives of the further solution together with the final solution are described. The aim of this thesis is to propose a fully functional section of a stamping line which will be easy for subsequent maintenance and also will correlate as much as possible with the standards of other sections of the lines within the company345 - Katedra mechanické technologiedobř

Complex Garnets : Microscopic Parameters Characterizing Afterglow

Light yield, time response, afterglow, and thermoluminescence of Ce-doped garnet scintillators and persistent luminescent materials are controlled by a complex interplay between recombination and trapping/detrapping processes. Extensive research has contributed to a good qualitative understanding of how traps, impurities, and the presence of Ce4+ affect the materials properties. In this work we present a quantitative model that can explain the thermoluminescence and afterglow behavior of complex garnets. In particular, the model allows the determination of capture rates and effective capture radii for electrons by traps and recombination centers in Lu1Gd2Ga3Al2O12:Ce garnet ceramics. The model relies on solving a set of coupled rate equations describing charge carrier trapping and recombination in garnet ceramics doped with Ce and also codoped with a known concentration of an intentionally added electron trap, Yb3+. The model is supported by analysis of a complete set of experimental data on afterglow, rise-time kinetics, and X-ray excited luminescence which show that thermoluminescence/afterglow are governed by trapping/detrapping processes following interactive kinetics with dominant recombination channel. The underlying reason for dominant recombination is the presence of a small fraction of Ce4+ (≈2 ppm in the 0.2% Ce-doped sample) which have a very high capture cross section (≈2.7 Å effective radius) because of the Coulomb attractive nature of this recombination center. The quantitative insights on capture cross sections and concentrations of Ce4+ help to better understand the optical properties of Ce-doped garnet scintillators and persistent luminescent materials and serve in optimizing synthesis procedures by tuning the Ce3+/Ce4+ ratio by codoping with divalent cations and annealing in an oxygen-containing atmosphere

Complex Garnets : Microscopic Parameters Characterizing Afterglow

Light yield, time response, afterglow, and thermoluminescence of Ce-doped garnet scintillators and persistent luminescent materials are controlled by a complex interplay between recombination and trapping/detrapping processes. Extensive research has contributed to a good qualitative understanding of how traps, impurities, and the presence of Ce4+ affect the materials properties. In this work we present a quantitative model that can explain the thermoluminescence and afterglow behavior of complex garnets. In particular, the model allows the determination of capture rates and effective capture radii for electrons by traps and recombination centers in Lu1Gd2Ga3Al2O12:Ce garnet ceramics. The model relies on solving a set of coupled rate equations describing charge carrier trapping and recombination in garnet ceramics doped with Ce and also codoped with a known concentration of an intentionally added electron trap, Yb3+. The model is supported by analysis of a complete set of experimental data on afterglow, rise-time kinetics, and X-ray excited luminescence which show that thermoluminescence/afterglow are governed by trapping/detrapping processes following interactive kinetics with dominant recombination channel. The underlying reason for dominant recombination is the presence of a small fraction of Ce4+ (≈2 ppm in the 0.2% Ce-doped sample) which have a very high capture cross section (≈2.7 Å effective radius) because of the Coulomb attractive nature of this recombination center. The quantitative insights on capture cross sections and concentrations of Ce4+ help to better understand the optical properties of Ce-doped garnet scintillators and persistent luminescent materials and serve in optimizing synthesis procedures by tuning the Ce3+/Ce4+ ratio by codoping with divalent cations and annealing in an oxygen-containing atmosphere