National Repository of Grey Literature 24 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Study of precipitation effects in Mg-Y and Mg-Y-Nd systems
Heteš, Michal ; Čížek, Jakub (advisor) ; Procházka, Ivan (referee)
The aim of this bachelor's thesis was to investigate the precipitation processes in the binary system Mg-Y and the ternary alloy Mg-Y-Nd using positron annihilation spect- roscopy and hardness testing, where we measured 2 samples with 3% and 6% by weight representation of Yttrium impurity atoms and 3 sample with 4% by weight representation of yttrium atoms and 3% by weight representation of neodymium atoms. The develop- ment of the hardness of the alloys was measured by the Vickers method of hardness measurement. Together with the hardness measurement, the characterization of crystal lattice disorders of the cloudy alloy samples was carried out using positron annihilation spectroscopy. It was measured that at higher temperatures hardening of the studied sys- tems occurs. Hardening was caused by the formation of GP zone precipitates and the β′ phase by Y, Nd and Mg atoms. 1
Low temperature polarized target for spin structure studies of nucleons at COMPASS
Pešek, Michael ; Finger, Miroslav (advisor) ; Procházka, Ivan (referee)
Title: Low temperature polarized target for spin structure studies of nucleons at COMPASS Author: Bc. Michael Pešek Department: Department of low temperature physics Supervisor of the master thesis: prof. Ing. Miroslav Finger, DrSc. Abstract: In presented thesis we describe concept of Deep Inelastic Scattering of leptons on nucleons in context of nucleon spin structure studies. Both polarized and unpolarized cases are discussed and concept of Transverse Momentum Dependent Parton Distribution Functions (TMD PDF) is introduced. The possibility of TMDs measurement using Semi-inclusive DIS (SIDIS) is described along with related results from COMPASS experiment. The future Drell-Yan programme at COMPASS is briefly mentioned and its importance is presented on the universality test i.e. change of sign of T-odd TMDs when measured in Drell-Yan and SIDIS. The importance of Polarized Target (PT) for spin structure studies is highlighted and principles of Dynamic Nuclear Polarization (DNP) are given using both Solid effect and spin temperature concept. COMPASS experiment is described in many details with accent given to PT. Finally the thermal equilibrium (TE) calibration procedure is described and carried out for 2010 and 2011 physics runs at COMPASS. The average polarization measurement results from 2010 and 2011 are...
Rationality of the Debtor
Procházka, Ivan ; Tuček, Milan (advisor) ; Kuchař, Pavel (referee)
This work deals with the indebtedness of consumers. It examines the causes of the debotrs themselves. Based on a secondary analysis of past research in the area of financial literacy, consumer behavior, statistical data, but also of qualitative research in the form of case study seeks to answer the question why the debtor becomes the debtor, the extent to which the indebtedness and indebtedness viewed as rational behavior but also if the debtor is accompanied by rational reasoning or irrational behavior. It concludes that the debtor can not be considered entirely rational. Applied policy then the issue of over-indebtedness problem takes into account the irrational assumptions by the debtor only marginally and does not reflect as one of its main causes.
Gas electron multiplier based photon detection for Cherenkov imaging applications
Krištof, Michal ; Finger, Michael (advisor) ; Procházka, Ivan (referee)
In the thesis we focus on the methods used to detect photons in Ring Imaging Cherenkov detectors, their description and the basics of the physical phenomena which lie behind them. We provide a brief description of the gaseous detector types and we describe the development of the new Thick GEM based detection system for the RICH-1 of the COMPASS experiment. We provide a detailed description of the latest tests and the convoluted route of the research done in the field. We review the ThGEM-based detector performance in comparison to the other methods of detection. Powered by TCPDF (www.tcpdf.org)
Causes and consequences of heavy households indebtedness
Procházka, Ivan ; Tuček, Milan (advisor) ; NÁHRADNÍ, OPONENT (referee)
Bachelor thesis Causes and consequences ofheavy household indebtedness deals over the issue of indebtedness of households in the Czech Republic. Finding the causes and examines the implications of this present phenomenon. The first part defines the trend of household heavy indebtedness, which is almost ten years, an upward trend, and that brings along the risk of insolvency. Furthermore, looking over and defines the causes household indebtedness. To this purpose, using an analysis of various stakeholders of this phenomenon. For each of them analyzes its interests, behavior, the relationship with other stakeholders, but also the possibility of interference with the issue. Finally, it summarizes all the findings and describes the interaction between various stakeholders.
Natural aging and early precipitation stages in Al-Mg-Si alloys
Lamač, Marcel ; Čížek, Jakub (advisor) ; Procházka, Ivan (referee)
Modern aluminium alloys 60xx are rich in sillicon and magnesium. They are easy to machine, are weldable, and can be precipitation-hardened, especially se- ries 6061, which we focus on in this thesis. Series 6061 alloy is currently the most general-purpose industrially used aluminium alloy. The purpose of this thesis is to analyze the natural and artificial aging of these alloys through the utilization of positron annihilation spectroscopy and coincidence Doppler broadening of anni- hilation radiation methods. Our goal is precise analysis of precipiation processes, which occur due to natural or artifical aging of the alloy. Although artifical aging in aluminium alloys is a well researched area, understanding and description of key mechanisms controlling the natural aging especially in the early stages of pre- cipitation is not yet sufficiently explained. We use modern methods of positron annihilation spectroscopy to understand and confirm our clustering hypotheses. 1
Microstructure and thermal stability of ultra fine grained Mg-Zn-Y alloys
Vlasák, Tomáš ; Čížek, Jakub (advisor) ; Procházka, Ivan (referee)
The aim of this diploma thesis is to investigate microstructure and thermal stability of ultra fine grained magnesium alloys. The thesis first summarises methods using plastic deformation in order to achieve ultra fine grained structure that are used to process metals. Then experimental methods employed in the experimental part including microhardness testing, scanning electron microscopy and positron annihilation spectroscopy are described. Brief summary of previous research on MgZnY alloys strengthened by quasicrystalline phases and Mg22Gd alloys is given. Finally, results of experimental investigation of MgZnY alloys with various Zn/Y ratios and Mg22Gd alloy are discussed. These results suggest that presence of phases in MgZnY alloys depend on Zn/Y ratio, hardness of these alloys depends on Zn content and that rapid cooling of MgZnY alloys annealed at 500 řC lead to significant increase in volume fraction of quasicrystalline icosahedral phase. In the second section of the experimental part thermal behaviour of Mg22Gd alloy is investigated. Furthermore, formation of GdH2 particles in Mg22Gd is examined and attributed to reaction of hydrogen decomposed from water vapour with gadolinium in areas rich in gadolinium. Finally, significant hardening of Mg22Gd alloy processed by high pressure torsion has been...
Gas electron multiplier based photon detection for Cherenkov imaging applications
Krištof, Michal ; Finger, Michael (advisor) ; Procházka, Ivan (referee)
In the thesis we focus on the methods used to detect photons in Ring Imaging Cherenkov detectors, their description and the basics of the physical phenomena which lie behind them. We provide a brief description of the gaseous detector types and we describe the development of the new Thick GEM based detection system for the RICH-1 of the COMPASS experiment. We provide a detailed description of the latest tests and the convoluted route of the research done in the field. We review the ThGEM-based detector performance in comparison to the other methods of detection. Powered by TCPDF (www.tcpdf.org)

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