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The influence of mechanical alloying on contamination of powder mixtures and bulk materials
Kubíček, Antonín ; Hadraba, Hynek (referee) ; Moravčík, Igor (advisor)
This thesis deals with the influence of process parameters on the contamination level of powder materials produced by mechanical alloying (MA) technology. For this purpose austenitic stainless steel 316 L and equiatomic CoCrFeNi high-entropy alloy (HEA) were prepared by high-energy ball milling. Both materials were milled in argon and nitrogen atmospheres from 5 to 30 hours. Spark plasma sintering method (SPS) was then used for consolidation of chosen powder samples. Chemical analysis of contamination within MA was carried out using combustion analysers for determination of carbon, oxygen, and nitrogen contents after different lengths of milling. Also differences in chemical composition of powder and corresponding bulk samples were measured. The microstructure analysis using scanning electron microscopy (SEM) of both powder and bulk materials was executed with focus on oxide and carbide presence and dispersion. Increasing content of carbon with increasing milling time was observed across all measured samples. This contamination is attributed to using milling vial made of tool steel AISI D2 (containing 1,55 wt. % of carbon). Increase of carbon content within consolidation using SPS was also observed. Milling of specimens using N2 as milling atmosphere caused higher contamination level in both AISI 316 L and HEA compared to milling in argon.
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Heat treatment of iron alloys with carbon
Kubíček, Antonín ; Štěpánek, Roman (referee) ; Čupera, Jan (advisor)
This thesis deals with the processes of heat treatment, their impacts on microstructure of iron alloys with carbon and their influence on hardness of these alloys. In the research part of this thesis are discussed the alloys, which are found within the Fe-Fe3C metastable system, principles and technologies of heat treatment processing with focus on the annealing, methods of microstructure examination and hardness measurement. In the experimental part is documented and evaluated the influence of various types of annealing on hypoeutectoid and hypereutectoid steels and the influence of graphitization on the hypoeutectic cast iron. The evaluation involves comparison of microstructures obtained by light and scanning electron microscopy and comparing the hardness in the green state and after annealing.
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The influence of mechanical alloying on contamination of powder mixtures and bulk materials
Kubíček, Antonín ; Hadraba, Hynek (referee) ; Moravčík, Igor (advisor)
This thesis deals with the influence of process parameters on the contamination level of powder materials produced by mechanical alloying (MA) technology. For this purpose austenitic stainless steel 316 L and equiatomic CoCrFeNi high-entropy alloy (HEA) were prepared by high-energy ball milling. Both materials were milled in argon and nitrogen atmospheres from 5 to 30 hours. Spark plasma sintering method (SPS) was then used for consolidation of chosen powder samples. Chemical analysis of contamination within MA was carried out using combustion analysers for determination of carbon, oxygen, and nitrogen contents after different lengths of milling. Also differences in chemical composition of powder and corresponding bulk samples were measured. The microstructure analysis using scanning electron microscopy (SEM) of both powder and bulk materials was executed with focus on oxide and carbide presence and dispersion. Increasing content of carbon with increasing milling time was observed across all measured samples. This contamination is attributed to using milling vial made of tool steel AISI D2 (containing 1,55 wt. % of carbon). Increase of carbon content within consolidation using SPS was also observed. Milling of specimens using N2 as milling atmosphere caused higher contamination level in both AISI 316 L and HEA compared to milling in argon.
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Heat treatment of iron alloys with carbon
Kubíček, Antonín ; Štěpánek, Roman (referee) ; Čupera, Jan (advisor)
This thesis deals with the processes of heat treatment, their impacts on microstructure of iron alloys with carbon and their influence on hardness of these alloys. In the research part of this thesis are discussed the alloys, which are found within the Fe-Fe3C metastable system, principles and technologies of heat treatment processing with focus on the annealing, methods of microstructure examination and hardness measurement. In the experimental part is documented and evaluated the influence of various types of annealing on hypoeutectoid and hypereutectoid steels and the influence of graphitization on the hypoeutectic cast iron. The evaluation involves comparison of microstructures obtained by light and scanning electron microscopy and comparing the hardness in the green state and after annealing.
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BASEL II vs BASEL III and the Impact of the New Regulatory Rules on the Czech Banking Sector
Kubíček, Antonín ; Dvořák, Petr (advisor) ; Janda, Karel (referee)
The aims of this thesis are twofold. Firstly, it aims to analyse the new regulatory rules BASEL III, published in December 2010. These were created as a lesson from the previous crisis and following the developments occurring problem areas included in the regulatory rules Basel II. And secondly, it evaluates their impact on the Czech Banking Sector. Regulatory rules BASEL III contain large number of rules aimed at enhancing the quality, quantity and flexibility of regulatory equity capital, reducing the cyclicality of capital requirements, stricter capital requirements for certain risky assets, intensifying surveillance in terms of significantly important financial institutions and international standards of liquidity. Apart from adjustment of the rules that appear in the Basel II, the regulatory rules Basel III also include rules used for the first time. The analysis of the impact on the Czech banking sector is based on the assumption that the Czech banking sector is well equipped with capital and the impact of BASEL III will therefore not have any significant impact on the functioning of Czech banks. This thesis shows that the impacts depend on the size of the banking institutions. A selected sample of six Czech banks (two from each group of large, medium and small banks) is used, inter alia, to demonstrate this.
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The Effect of Introduction of Basel II on Capital Adequacy of Selected Czech Banks
Kubíček, Antonín ; Dvořák, Petr (advisor)
The aim of this bachelor thesis is to evaluate the impact of new rules for calculating capital adequacy in the Czech banking sector in general and then in the selected sample of four banks. The subject of my analysis is the relative amount of capital adequacy before and after implementation of Basel II across the Czech banking sector and the capital requirements before and after implementation of Basel II which showed the selected four banks. The question I want to answer is the extent to which new practices that Basel II allows banks to use for calculating the capital requirements for credit and operational risk change the relative level of capital adequacy and the total amount of capital requirements in banks selected by me.
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