National Repository of Grey Literature 727 records found  previous11 - 20nextend  jump to record: Search took 0.11 seconds. 

Study of Low Cycle Fatigue Properties of Magnesium Alloy AZ31 with 0,5% Calcium.
Gejdoš, Pavel ; Věchet, Stanislav (referee) ; Podrábský, Tomáš (advisor)
In this work have been identified mechanical and fatigue properties of magnesium alloy AZ31 with 0.5% calcium, which was cast using squeeze casting. In addition, it was observed microstructure of the alloys and made fractographic assessment of fracture surfaces after fatigue loading.

Heat insulating moulded refractory materials
Novotný, Radoslav ; Lang, Karel (referee) ; Raschman,, Pavel (referee) ; Havlica, Jaromír (advisor)
Doctoral thesis is focused on the study, research and development of heat insulating moulded refractory materials. The replacement of shaped instead of unshaped refractories is recently and strongly industrially demanded and belongs to ongoing research topics. With the increasing demand of energy savings, the excellent insulation properties are essential. The insulating properties of castables are the result of targeted porosity formation. The porosity is coming from the controlled air intrusion into material resulted to foamed structure. The foaming process was achieved by mixing of separately prepared aqueous foam into raw castable slurry or by in situ foaming of intensively mixed castable slurry with the surfactant additive. Nevertheless, the study of foam behaviour and the influence of additives on binder hydration and setting processes (i.e. calciumaluminate cement) was substantial for successful preparation of the experimental samples. The two types of the experimental samples were prepared. The first one was based on mixing of kaolin slurry with pre-prepared aqueous foam, whereas the de-aglomeration ability of kaolin specie was utilized to water-particle film formation. In situ foaming of multicomponent system is the second one. The both processes brought some negative attributes, so the optimal properties of prepared castables were achieved by their combination.

Theoretical and experimental study of a Wien filter properties for using at the very-low-energy scanning electron microscope
Vlček, Ivan
Results of Wien filter study are employed for design of a very low-energy scanning microscope. A Wien filter serves as a separator of primary and signal electrons in this arrangement. The paper describes design of other optical parts of the microscope: objective lens, deflection system and CCD detector optics.

Study of dielectrical properties of organic material thin films
Pospíšil, Jan ; Boušek, Jaroslav (referee) ; Mikula, Milan (referee) ; Zmeškal, Oldřich (advisor)
The dissertation is focused on the study of electric and especially dielectric properties of thin film organic materials with their huge potential for optoelectronics and other industrial sectors. The theoretical part deals with the use of organic materials in organic photovoltaic cells, the methods of deposition techniques and characterization. The theoretical knowledge of the dielectric spectroscopy, including methods for determining the physical properties and evaluation of experimental data are also described. The experimental part is devoted to the study of small molecule organic solar cells with bulk heterojunction composed of electron donor molecule of DPP(TBFu)2 and electron acceptor fullerene derivatives, such as PC60BM, PC70BM and TC60BM. The experimental part is divided into two main parts. The first part deals with the study of processes occurring at the interface between the active layer and the contact; the second part is focused on transport processes inside the structure of photovoltaic cells and also contains a study of perovskite solar cells.

Relationship between petrographic parameters and technological properties of clastic sedimentary rocks used for crushed stone
Čermák, Martin ; Přikryl, Richard (advisor) ; Krutilová, Kateřina (referee)
This diploma thesis is focused on the finding and describing of the relationships between petrological parameters and technological properties of rocks used for the production of aggregates (crushed stone). Rock specimens were selected from a geological area of Culm (Lower Carboniferous age) in the area of Nízký Jeseník Mts. and Drahanská vrchovina uplands in the Czech Republic. Studied localities were selected on the basis of the current quarrying operations and also to represent the different strata. The six studied localities encompass Kobylí, Chabičov, and Bělkovice where Horní Benešov formation of Nízký Jeseník is exposed. Locality Valšov represents Andělské Hory formation and locality Nová Ves and Loštice represent Protivanov formation of Drahanská vrchovina uplands. Two specimens were taken from the locality Loštice (one from the second cut because there are produced low-grade aggregates and the third cut where high quality crushed stone is produced). A detailed mineralogical-petrographic examination of the samples was the first step, in an attempt to obtain their mineralogical composition and to identify the major rock-forming clasts. Thin sections were examined by standard polarizing microscopy. The auxiliary UV lamp and thin sections saturated by fluorescent substance were used for the...

Application of Fredholm's theorems to the existnce of solutions to systems of Stokes type
Mácha, Václav ; Stará, Jana (advisor) ; Kaplický, Petr (referee)
Presented work deals with the existence and uniqueness of solution of generalized Stokes problem. The study of this problem is motivated by the research concerning partial regularity of weak solutions of systems describing the flow of incompressible fluids whose viscosity depends on the pressure and the shear rate. The explanation of the connection between presented problems is desribed in the first chapter, which includes also some models of viscosity. In following chapters the existence and uniqueness of solutions are studied with regard to the changing parametrs in models of viscosity. For this purpose I use compact embeddings followed by appropriate application of Fredholms theorems. At the end of the work the constructed theory is applied to one viscosity model.

Cluster studies in molecular beams
Profant, Václav ; Kužel, Petr (referee) ; Dian, Juraj (advisor)
In the present work we study properties of clusters of small heteroatomic molecules with biological relevance by several experimental methods based on molecular beams. In the rst experiment structure and dynamics of size-selected charged pyrrole clusters have been studied by means of molecular beam scattering experiment. Small neutral P yn clusters were produced in Py/He expansions and larger mixed P ynArm clusters in Py/Ar expansions, and the scattering experiment with a secondary beam of He atoms was used to select the neutral clusters of dierent sizes. The complete size-selected fragmentation patterns for the neutral dimer to tetramer after an electron impact ionization at 70 eV from the measurements of the angular and velocity distributions at dierent fragment masses. In second experiment photolysis of size selected pyrrole, imidazole and pyrazole clusters has been investigated. Comparison with the photolysis of an isolated molecules and between studied systems has been made. Clusters were photolyzed at 243 and 193 nm and the kinetic energy distributions of the H-photofragments have been measured and analyzed. Finally the mass spectra of the fragments after multiphoton ionization have been measured. The signicant inuence of the cluster environment to the photolytic behavior was observed and discussed.

Ruby on Rails and Grails - frameworks for web application development
Černý, Michael ; Pavlíčková, Jarmila (advisor) ; Lukáš, Martin (referee)
The thesis compares web frameworks Ruby on Rails and Grails. The main goal of the thesis is to compare which of these frameworks is more convenient for development of web applications using wide range of criteria. The first part of the thesis defines fundamental terms to understand the web frameworks topic. Subsequently the thesis analyzes the history, language and fundamental characteristics of both frameworks. The next section describes all the details of the reference applications in Ruby on Rails and Grails, that are part of this diploma thesis. The most important part of this thesis is the comparison of both frameworks using a number of criteria. The thesis should provide sufficient amount of information to understand the web frameworks, to obtain the fundamentals for working with the web frameworks Ruby and Rails and Grails and it should bring enough information for optimum choice between these frameworks for development of web application and for future studies. The thesis could be of benefit to both students, that decide what to study in the future, and managers or project leaders, that decide which web framework to use.

STUDY OF POTENTIAL PHARMACOLOGICAL PROTECTION OF CARDIAC CELLS AGAINST OXIDATIVE STRESS AND ANTRACYCLINE ANTICANCER DRUGS
Jansová, Hana ; Šimůnek, Tomáš (advisor) ; Hrdina, Radomír (referee) ; Jun, Daniel (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ DEPARTMENT OF BIOCHEMICAL SCIENCES Candidate: Mgr. Hana Jansová Supervisor: Doc. PharmDr. Tomáš Šimůnek, Ph.D. Title of Doctoral Thesis: STUDY OF POTENTIAL PHARMACOLOGICAL PROTECTION OF CARDIAC CELLS AGAINST OXIDATIVE STRESS AND ANTRACYCLINE ANTICANCER DRUGS Development of cardiovascular disorders is associated with various risk factors and oxidative stress plays an important role in many of them. Iron-catalysed production of highly toxic and reactive hydroxyl radicals may contribute to oxidative stress. Chelation of free iron seems to be a promising strategy to prevent the propagation of oxidative stress. However, the use of classic iron chelators in pathological conditions without iron overload is associated with the risk of toxicity due to the iron depletion. Hence, this study deals with cardioprotective properties of iron chelators as well as prochelators derived from them. We focused on prochelators with almost no affinity for iron ions until they are activated under disease-specific oxidative stress conditions. For a long time, it has been assumed that oxidative stress is also the main denominator in an anthracycline-induced cardiotoxicity. However, the previous studies suggested alternative mechanism(s). Therefore in the...

Development and application of methods used in devices for study of local properties of nanostructures
Sháněl, Ondřej ; Fejfar, Antonín (referee) ; Šikola, Tomáš (advisor)
Vývoj UHV kompatibilního kombinovaného systému AFM/SEM. Modifikace předchozího AFM mikroskopu pro podmínky spojené s tímto systémem. Výzkum transportu elektrického náboje v organických solárních článcích pomocí měření jejich volt-ampérových charakteristik a povrchového potenciálu. Příprava zlatých hrotů pro STM netoxickou cestou.