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Investigation of deformation mechanisms in Mg-Gd alloys
Szabóová, Andrea ; Mathis, Kristián (advisor) ; Drozdenko, Daria (referee)
Title: Investigation of deformation mechanisms in Mg-Gd alloys Author: Andrea Szabóová Department: Department of Physics of Materials Supervisor: doc. RNDr. Kristián Mathis, DrSc. Abstract: In the present work, the deformation behavior of magnesium-gadolinium binary alloys was investigated. Dependence on the concentration of Gd and deformation temperatures was studied. Extruded samples had relatively strong initial texture. Compression tests were done at room temperature and 200řC. Simultaneously with deformation acoustic emission was recorded. Data from acoustic emission was analyzed with advanced statistical methods. Results of the combination of these two experimental methods indicated that at the beginning of the deformation twinning is the dominant mechanism. In the following stage of plastic deformation non-basal slip systems became the governing deformation mechanism. With higher content of Gd the size of twins decreases as a result of the decreased mobility of twin boundaries caused by solute atoms. At higher temperatures twinning activity was increasing. In addition, results were confirmed by optical light and scanning electron microscopy. Keywords: magnesium alloy, deformation tests, acoustic emission, microscopy
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Investigation of the dynamics of the deformation processes in Mg-RE alloys using in-situ experimental methods
Szabóová, Andrea ; Mathis, Kristián (advisor) ; Drozd, Zdeněk (referee)
In this present work, the dynamics of deformation mechanisms activated in binary magnesium-gadolinium alloys with respect to amount of Gd were investigated with in-situ experimental methods. Cast alloys are characterized by random texture. Compression test were done at room temperature with simultaneous record of acoustic emission response. The acoustic emission signal was subsequently analysed using advanced clustering method providing information about the dominant deformation mechanisms. High speed camera was used to study the dynamics of twinning, including estimation of the velocity of twin propagation with respect to Gd concentration. The deformation tests were repeated in a chamber of scanning electron microscope (in-situ SEM) with concurrent following the microstructure development using secondary electrons and electron back-scattered diffraction (EBSD) in different stages of the deformation. Main goal of this measurements was to identify active slip systems and the progress of twin volume fraction during deformation. Keywords: magnesium alloy, deformation tests, acoustic emission, high-speed camera, electron microscopy, twinning
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Investigation of deformation mechanisms in Mg-Gd alloys
Szabóová, Andrea ; Mathis, Kristián (advisor) ; Drozdenko, Daria (referee)
Title: Investigation of deformation mechanisms in Mg-Gd alloys Author: Andrea Szabóová Department: Department of Physics of Materials Supervisor: doc. RNDr. Kristián Mathis, DrSc. Abstract: In the present work, the deformation behavior of magnesium-gadolinium binary alloys was investigated. Dependence on the concentration of Gd and deformation temperatures was studied. Extruded samples had relatively strong initial texture. Compression tests were done at room temperature and 200řC. Simultaneously with deformation acoustic emission was recorded. Data from acoustic emission was analyzed with advanced statistical methods. Results of the combination of these two experimental methods indicated that at the beginning of the deformation twinning is the dominant mechanism. In the following stage of plastic deformation non-basal slip systems became the governing deformation mechanism. With higher content of Gd the size of twins decreases as a result of the decreased mobility of twin boundaries caused by solute atoms. At higher temperatures twinning activity was increasing. In addition, results were confirmed by optical light and scanning electron microscopy. Keywords: magnesium alloy, deformation tests, acoustic emission, microscopy
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The comparison of social services in the Czech Republic and EU states in the period 2000-2012
Szabóová, Andrea ; Krebs, Vojtěch (advisor) ; Kubelková, Karina (referee)
The social services system in the Czech Republic intended for people in unfavorable social situation requires increased attention to financial sustainability, quality and overall effectiveness of their providing. The main point of this work is to examine and analyze the development of an instrument of social policy -- social services in the Czech Republic and in selected EU countries in the period 2000 - 2012. It is possible to highlight the weaknesses of the Czech system of social services by following comparison of the basic pillars. Positive and innovative experience of some EU countries is one of the possible ways how to solve defects in the Czech Republic.
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The success of the social enterprise concept in Slovakia
Szabóová, Andrea ; Kubelková, Karina (advisor) ; Kotýnková, Magdalena (referee)
A new instrument of active employment policy -- social enterprise has appeared in Slovakia. This concept is aimed at creating new job vacancies for disadvantaged job applicants. The aim of this work is to focus on the effectiveness of a running project, i. e. efficiency of invested resources, efficiency of new job vacancies creation and to draw any conclusions for continuing social enterprises functioning in Slovakia. The work consists of three parts. The first part monitors the historical concept development and its theoretical basis. The second part describes the functioning of social cooperatives in Italy which tradition lasts the longest and have also become an inspiration for Slovakia. Finally, the third part is dedicated to what is happening in the social enterprises in Slovakia and temporary conclusions of the running project.
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