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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Polární fosfinoferrocenové ligandy s uhlovodíkovými spojkami / Polar phosphinoferrocene ligands with hydrocarbyl bridges

Zábranský, Martin January 2019 (has links)
A new synthetic route towards methylene-spaced hybrid phosphinoferrocene ligands was developed, making use of a phosphinoferrocene betaine 3-(N,N,N-{[1'-(diphenylphosphino)- ferrocenyl]methyl}dimethylammonium)propane-1-sulfonate (2), that is readily accessible from 1-(diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene (XIX) via treatment with 1,3-propanesultone. The betaine 2 was reacted with sodium alkylsulfinates (alkyl = methyl, phenyl, 4-tolyl) to afford the corresponding sulfones 4. The coordination chemistry of [1'-(diphenylphosphino)ferrocenyl]methyl(methyl)sulfone (4a) was investigated in its zinc(II) complexes. Surprisingly, only insoluble mixed-metal coordination polymers of the general formula [MZnX3(4a)(MeOH)]n (M/X = Na/Br, K/Br, Na/I) and six-centre complex [Li2Zn2Br6(4a)2(MeOH)4(H2O)] could be obtained. Two isomeric homologues of 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf, II), viz. 1'-(diphenylphosphino)ferrocenylacetic acid (HIIa) and 1'- [(diphenylphosphino)methyl]ferrocene-1-carboxylic acid (HIIb), were prepared and their coordination preferences were assessed in their palladium(II) complexes. The palladium(II) complexes were prepared by reacting various (acetylacetonate)palladium(II) precursors with these acids with concomitant release of acetylacetone....
82

Studium syntézy a struktury keramických perovskitových materiálů pro energetické aplikace / Study of the synthesis and structure of ceramic perovskite materials for energy applications

Strejček, Josef January 2010 (has links)
Method, so called “glycin- nitrate process”, combined with high temperature solid state reaction, of preparation multi- component ceramic perovskite materials was studied. Two types of perovskite systems were prepared by this method. Firs one, based on LaNiO3 doped by calcium and aluminium and second one, based on SmFeO3 doped by calcium and nickel or cobalt. This method made possible preparation of one phase perovskite or perovskites with few percent of nickel in form of oxide. In systems containing both nickel and calcium another phases rich in calcium and nickel appeared.
83

Příprava inhibitorů chřipkové neuraminidasy a polymerasy / Preparation of Influenza Neuraminidase and Polymerase Inhibitors

Zima, Václav January 2021 (has links)
Influenza is an infectious disease caused by the influenza virus. This virus causes a severe viral infection that spreads easily from person to person in yearly pandemics. Vaccination is the most effective way to prevent the infection, however, due to the high rate in mutations of the virus, the vaccine needs to be often reformulated. Another option to combat influenza is based on administration of antiviral drugs. Clinical studies of isolated influenza strains ("avian flu" H5N1, 2004; "swine flu" H1N1, 2009) revealed resistance towards known influenza neuraminidase inhibitors (zanamivir, oseltamivir). The resistance is caused by structural changes close to the enzymatic site. This calls for the development of new neuraminidase inhibitors as well for development of inhibitors targeting different influenza enzymes. This Thesis is focused on design and synthesis of new inhibitors of influenza neuraminidase and RNA-dependent RNA polymerase, namely PA subunit and the assembly of PA-PB1 heterodimer enzymes (Scheme 1). Influenza neuraminidase inhibitors were prepared by C-5 derivatization of oseltamivir followed by subsequent extension of its structure with binders of 150-cavity. Binding potencies of new oseltamivir derivatives against two influenza strains were determined. The next part contributed to...
84

Syntéza a příprava bezolovnaté piezokeramiky / Synthesis and fabrication of lead-free piezoceramics

Řeháková, Bára January 2018 (has links)
The topic of this thesis is synthesis and preparation of lead-free pizoceramic with perovskite structure, in particular potassium-sodium niobate (KNN). In theoretical part are described possibilities of KNN synthesis and of it’s shaping and sintering. Experimental part deals with three types of synthesis described in the theretical part – solid state reaction, hydrothermal synthesis, sol-gel synthesis, and subconsequentional shaping of prepared powders by uniaxial pressing, cold isostatic pressure method, sintering (classical in oven, in some cases SPS – spark plasma sintering) of such green body and their following properties like relative density, grain size or charge constant. Preparation of KNN powder by each described method took place, followed by shaping and sintering. Best properties were shown by SPS sintered samples, which reached the highest density and lowest grain growth.
85

Digitální elektronický hudební syntezátor s analogovým řízením pro platformu Eurorack / Digital Musical Synthesizer with Analog Control for Eurorack Platform

Klecl, Martin January 2019 (has links)
This work explores the topic of digital audio signal processing for modular synthesizers and the design of digital oscillator for modular standard known as Eurorack. Introduction of the theoretical part is dedicated to basic terms and blocks used in modular synthesizers. The thesis also characterizes and presents the methods of sound synthesis. The second part of the theory concerns analog and digital signal conversion made by digital signal processors DSP, focusing on ARM with focus on ARM architecture. The practical part of the thesis concerns design and construction of the digital oscillator which generates periodic waveforms without aliasing distortion. The oscillator also allows several types of modulations and waveforming and the module has several inputs for connecting control voltages or external audio signals.
86

Kmitočtové syntezátory / Frequency Synthesizers

Lapčík, Josef January 2011 (has links)
This diploma thesis concerns with analysis and dividing of frequency synthesizers and design of DDS, PLL synthesizers. Base types of frequency synthesizers are described including differences between methods of their operation. Base circuits of both – DDS and PLL synthesizers and other important circuits are described in details at design part of this thesis. Design of DDS and PLL synthesizer is described in particular sections. Both synthesizers are directly realized and stand-alone control applications are created. PLL synthesizer is also ready to control thru Agilent VEE program environment. Particular example application is designed in Agilent VEE. This application is used as basis of attached lab project.
87

Implementing and Improving a Speech Synthesis System / Implementing and Improving a Speech Synthesis System

Beněk, Tomáš January 2014 (has links)
Tato práce se zabývá syntézou řeči z textu. V práci je podán základní teoretický úvod do syntézy řeči z textu. Práce je postavena na MARY TTS systému, který umožňuje využít existujících modulů k vytvoření vlastního systému pro syntézu řeči z textu, a syntéze řeči pomocí skrytých Markovových modelů natrénovaných na vytvořené řečové databázi. Bylo vytvořeno několik jednoduchých programů ulehčujících vytvoření databáze a přidání nového jazyka a hlasu pro MARY TTS systém bylo demonstrováno. Byl vytvořen a publikován modul a hlas pro Český jazyk. Byl popsán a implementován algoritmus pro přepis grafémů na fonémy.
88

Kantova nauka o schematismu / Kant's Theory of Schematism

Bis, Ondřej January 2015 (has links)
The thesis focuses on a chapter from Kant's Critique of Pure Reason, "The Schematism of the Pure Concepts of the Understanding". Kant assumes two independent sources of knowledge, understanding and intuition. These sources need to be overcome, because of their heterogeneity. Schematism is closely related to "The Deduction of the Pure Concepts of the Understanding". That is why the analysis of schemata is preceded by the analysis of this chapter. It shows a more detailed description of a role of intuition with respect to understanding. Firstly, the validity of the categories regarding whatever form of intuition is proved. Secondly, the proof of the validity of the categories regarding specific forms of time and space follows. The chapter on schematism deals with the specific methods by means of which the categories relate to intuition. Kant introduces transcendental schemata bridging the heterogeneity of understanding and intuition. The relation between category and schema is understood as one of analogy. The categories are rules of discursive type of unity of any kind of intuition, whereas schemata are determined as rules of perceptive unity of intuition. Intuition is brought under unity of apperception by means of schemata of imagination. Inseparable part of the thesis is the schematism of...
89

Interactive Preview Renderer for Complex Camera Models / Interactive Preview Renderer for Complex Camera Models

Zámečník, Bohumír January 2012 (has links)
Title: Interactive Preview Renderer for Complex Camera Models Author: Bohumír Zámečník Department: Department of Software and Computer Science Education Supervisor: Dr. Alexander Wilkie Supervisor's e-mail address: alexander@wilkie.at Abstract: An interactive renderer was implemented that allows users to preview the effects of imaging with lenses, such as depth of field, bokeh (defocus highlights) and tilt-shift lens configurations. It is based on a state-of-the-art method which com- bines the power of GPU rasterization and ray tracing. Many models and interactive visualizations were created. A non-interactive simulation of a complex geometrical lens model has been made which is able to produce optical aberrations. Also a prototype implementation of recent fast spreading filters is available. A thorough summary of the principles of optical image formation, lens models and depth of field rendering methods used in computer graphics is given along with a comparison of the approaches and new insights. New possibilities of representing the behavior of complex lenses are suggested, which could be employed to accelerate the rendering. Keywords: image synthesis, camera models, depth of field, GPU, image-based ray tracing
90

Komparace filosofie Jana Amose Komenského a René Descarta / Comparison Philosophies of Jan Amos Komenský and René Descartes

Dobrovodská, Helena January 2015 (has links)
Comparison of Philosophies of Jan Ámos Komenský and René Descartes The aim of this work is comparison of philosophies of Jan Ámos Komenský and René Descartes based on their essential works, i.e."Labyrint světa a ráj srdce" (The Labyrinth of the World and the Paradise of the Heart) and "Úvahy o první filozofii" (Meditations on First Philosophy), in which God's existence and the difference between the human soul and body are proved. The philosophy of both contemporaries originated in the 17th century on the background of the Thirty Years' War and the Counter-Reformation. The rationalism of René Descartes, which starts Cartesian thinking, seems to be substantially different from the philosophy of Komenský based on Neoplatonism and Christianity. In the thought of Descartes analysis, mathematical operationalism, is principal, whereas Komenský synthesizes and puts the whole together. The first chapter of the thesis deals with the lives, period and works of Komenský and Descartes. It is possible to find significant similarities in their life stories. The second chapter deals with the interpretation of "The Labyrint of the World and the Paradise of the Heart" and the interpretation of "Meditations of First Philosophy", in which God's existence and the difference between the human soul and body are proved....

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