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Ab initio calculation of doping in Ni2MnGa alloy
Janovec, Jozef ; Černý, Miroslav (referee) ; Zelený, Martin (advisor)
Cieľom tejto práce je teoretické štúdium systému Ni-Mn-Ga, vykazujúceho efekt magnetickej tvarovej pamäti. Pri výpočtoch bola použitá metóda Exaktných Mufiin-Tin Orbitálov v kombinácii s aproximáciou koherentného potenciálu vrámci Korringa-Kohn-Rostoker formalizmu. Totálna energia bola spočítaná pomocou metódy úplnej nábojovej hustoty. Skúmaný bol vplyv dopovania zinkom alebo kadmiom na totálne energie pozdĺž tetragonálnej deformačnej dráhy a následne na teplotu martenzitickej premeny TM a Curieho teplotu TC. Taktiež boli skúmané nestechiometrické zliatiny prebytkom Mn na úkor Ga. Výsledky predikujú nárast TM po všetkých pozorovaných substitúciách v podmriežke Ga a pokles TM po substitúciách v podmriežke Mn. Curieho teplotu znižujú všetky študované substitúcie s výnimkou zmeny magnetického usporiadania v martensite nestechiometrickej zliatiny.
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Hybrid Blends of Recycled Plastics
Černý, Miroslav ; Lehocký, Marián (referee) ; Balgová,, Vendula (referee) ; Jančář, Josef (advisor)
Work describes the relationship between structure and mechanical properties in case of hybrid mixtures. They are composed from polyurethane matrices (eventually polyurethane-urea or polyurethane-inorganic filler mixtures), different rubber fractions as filler and eventually reinforcement made from PET monofilaments. Mechanical behaviour was studied by tensile testing. Studied mechanical properties include tensile modulus, ultimate strength and strain and also specific energy need neccessary for ultimate strength achievement. Prepared materials are naturally porous. Therefore their mechanical behaviour has to be described generally for porous composites. The porosity occurence means, that it is difficult to describe them by models valid for mechanical behaviour (mainly elastic modulus) of nonporous composites. Models are also based on idealized structures on microscopic level. In case of porous composites, it is very difficult to create any idealized structure. The structure is changed with modifications of composition (change of components or their rates). These conditions have lead to utilizing of different approach how to describe the relationship between structure and mentioned mechanical properties. The chosen approach comes from knewledge about structural parametres coming from porosity. Structural parameters describe the structure on macroscopic level. They include interspace volume (volume lying between filler particles), interspace filling (how the matrix fills the interspace volume) and matrix volume fraction. Proposed parameters are used in relations, where they are fitted by exponents to interlay values of chosen mechanical properties for composites containing discrete matrix and filler. Found exponents are then described by properties of matrices to obtain relations describing properties of filled porous materials. Very similar approach was chosen for description in the case of reinforced composites. Proposed relation are potentially valid for materials containing binding matrix, infinity count of fillers and one kind of reinforcement.
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Analysis of employment agencies
Černý, Miroslav ; Štědroň, Bohumír (advisor) ; Janák, Vladimír (referee)
Title: Analysis of employment agencies Objectives: The aim of this thesis is to explore employment agencies on Czech labour market and find out its functionality and credibility from the side of job seeker. One of the constitutive aim was also using the marketing method Mystery client. The term functionality of employmenet agencies was evaluated as attitude and ability of employment agency to mediate good job for job seekers. Methods: To obtain data, that allows to final evaluation, was used special technique of market research called Mystery client. This method represents hidden observation during job interview. The research was completed with question survey of selected staff consultants. Results: The results of the research indicated that employment agencies are mainly focused on outsourcing and are usually mediating short-term job for young and less educated people. The research also indicated that employment agencies are not able to mediate appropriate job in reached level of education. In spite of these problems, there were recommended three employment agencies that are properly able to communicate and react for job supply and demand. Key words: Employment agency, analysis, mystery shopping, mystery client, questionnaire
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Bio-based composites made from lactic acid resins
Smiřický, Jan ; Černý, Miroslav (referee) ; Figalla, Silvestr (advisor)
This bachelor thesis is about the synthesis of polyurethane glue, which is capable of gluing together sawdust, and about the testing of the mechanical characteristics of the glue and sawdust compostion. This glue is biodegradable and is created from renewable resources, this is why it could be an appropriate replacement for phenol formaldehyde, melamine, and urea formaldehyde resins. Another indisputable advantage is the absence of arenes in the macromolecule structure, which can be carcinogenic. In this synthesis, the compounds polylactic acid and hexamethylene diisocyanate were chosen, the former as the polyol and the latter as the isocyanate. In the theoretical section of the thesis, the used compounds are described in terms of their characteristics, their creation and the tests of the composites as well. In the experimental section, the conducted experiments are described.
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Analysis of wave-particle interactions in space plasmas
Černý, Miroslav ; Santolík, Ondřej (advisor) ; Souček, Jan (referee)
This work deals with the linear analysis of plasma waves, especially with the methods of solution of a hot plasma dispersion relation. There are cited some results achieved in the space plasma research and mapped current numerical methods of their analysis. Besides, this work introduces a new numeric procedure, computer code PDRS (Plasma Dispersion Relation Solver), which allows finding solution of a dispersion function of a cold or hot plasma with general distribution function. It also demonstrates the usage of the PDRS methods on real examples of waves in space plasma based on the spacecraft Cluster measurement.
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Attitudes of football fans in lower league
Černý, Miroslav ; Janák, Vladimír (advisor) ; Šíma, Jan (referee)
Attitudes of football fans in lower league Objectives: The aim of the work is to find out the attitudes and motives of people to active visitation of football matches in lower league. Then I would like to introdukce a gained knowledges to the head of the clubs in order to reach a higher level of satisfaction of fans. Methods: Questionnaire, interview Results: It will find out the attitudes of fans in lower leagues thanks to mentioned methods of research. The work will present the view of individual behaviour and Leeds of fans in lower league. Keywords: Lower league, football, attitudes, spectators
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Monitoring of the expression of mRNA for CD 105 in patients with the chronic lymphocytic leukemia
Černý, Miroslav ; Fátorová, Ilona (advisor) ; Nekvindová, Jana (referee)
CHARLES UNIVERSITY IN PRAGUE Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Candidate: Bc. Miroslav Černý Supervisor: Mgr. Ilona Fátorová Consultant: Mgr. Filip Vrbacký Title of diploma thesis: Monitoring of the expression of mRNA for CD105 in patients with the chronic lymphocytic leukemia Chronic lymphocytic leukemia (CLL) is heterogenous disease with very variable clinical course. Early determination of prognosis of this disorder can be helpful for finding and initiation of adequate individual therapy. Angiogenesis has prognostic potential and plays probably important role in pathogenesis of CLL. Endoglin (CD105) and angiopoietin 2 (Ang-2) also belong to angiogenic molecules. Data about expression of these molecules are still insufficient. Therefore, we quantitated CD105 and Ang-2 mRNA in B cells of 49 untreated CLL patients by using the method of real-time quantitative PCR. Subsequently, we compared the expression of these angiogenic molecules to traditional as well as modern biological prognostic factors(Rai clinical stage, disease course, IgVH mutation status, expression of ZAP70 and CD38). We found statistical significant association between expression of CD105 and all traditional or modern prognostic factors (Rai0 versus I - IV: p = 0,004; disease course:...
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FIRST PRINCIPLES ANALYSIS OF MECHANICAL STABILITY OF SOLID CRYSTALS
Řehák, Petr ; Buršík, Jiří (referee) ; Šob, Mojmír (referee) ; Černý, Miroslav (advisor)
The aim of the author’s research in the period of his PhD study was the analysis of mechanical stability of cubic crystals under external loading. This work demonstrates several methods used for a study of mechanical stability of fcc crystals (C, Al, Ir, Pt, Au) during isotropic (hydrostatic) tensile loading. Ab initio methods were used for this purpose. Studied crystals were subjected to simulated isotropic tensile deformation and an analysis of elastic stability was performed. This analysis shows that first elastic instability in Al, Pt and Au crystals corresponds to vanishing of the trigonal shear modulus and diamond, Ir remains stable up to the state of maximum isotropic stress. According to the calculated band structure diamond crystal preserves his insulating character up to the onset of instability. Consequently, phonon spectra of all crystals were calculated using the linear response method and their dynamic stability was assessed. Obtained results reveal soft phonon modes in Al, Pt and Ir before an occurrence of elastic instability. Selected short-wavelength instabilities are confirmed using models of microscopic deformation and also using dispersion curves obtained by a supercell method. The observed instabilities lower critical strains related to the volumetric instability up to 40 % whereas the reduction of critical stress is by 20 % at the most.
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QUANTUM MECHANICAL STUDY OF PHASE STABILITY IN METALLIC SYSTEMS
Káňa, Tomáš ; Vřešťál, Jan (referee) ; Paidar,, Václav (referee) ; Černý, Miroslav (referee) ; Šob, Mojmír (advisor)
This work presents a theoretical study of stability of phases in selected metallic systems. We propose a model of structural transformations in transition metal disilicides MoSi2, CrSi2, VSi2 and TiSi2 and in Pd thin films grown on cubic substrates W(001) and Nb(001). The obtained results yield the total energy proles for the structural transformations studied, the activation energies needed for each individual transformation and an estimate of the temperature at which the structure can transform. The total energies are calculated by full-potential linearized augmented plane waves (FLAPW) method incorporated in the WIEN2k code. Both generalized gradient approximation (GGA) and local density approximation (LDA) are employed for the exchange-correlation term. It turns out that temperatures corresponding to the activation energies of structural transformations in transition metal disilicides exceed their melting temperatures. Comparing the resulting total energy proles to those obtained by the semiempirical Bond Order interatomic potentials (BOP) substantially helps to adjust the fitting parameters of the BOPs. The estimated temperature of 168 K needed to transform the hcp structure of an innite Pd crystal into the dhcp structure explains the behavior of the Pd thin lm on W(001) and Nb(001) substrates. Pd lms deposited on W(001) substrate and thicker than about 100 monolayers undergo this transformation already at room temperature. Thinner lms need to be annealed at 400 K rst, due to their stronger interaction with the substrate. The difference between the computed result and a real temperature at which the hcp Pd lm transforms its structure to the dhcp can be explained by both the interaction between the lm and the substrate and by the inuence of the domain topology of the lm. Analyzing different models of transformation of the initial hcp Pd structure to the ground state fcc structure, we identied the optimum model that respects the domain topology of the Pd lm.
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