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Preparation and testing of lightweight composite materials
Peroutka, Jakub ; Bartlová, Milada (referee) ; Žídek, Jan (advisor)
This thesis deals with simulation of composite origami-like auxetic materials, which exhibit self – assembly effect (SE). The freeware named INKSCAPE was used for preparing structures. Simulations were made by MATLAB with GIBBON plugin using finite element method. For structure evaluation, freeware programme FEBIO Studio were used. The theoretical part was divided into four sections – auxetic materials, shape memory polymer materials, self-assembly auxetic materials and thermal expansion of auxetic materials. Each section contains of basic information and knowledge from its category. For each area of the theoretical part, literature searches were conducted based on the latest findings on the given topic. The experimental part consisted of simulations of prepared structures and their subsequent evalution using MATLAB programme. Simulations were performed for two types of auxetic structures that differed in the size of external angle (121,99 °and 131,78 °) in total. In the next step, simulation of cubic structure with dimensions 20 × 20 mm was performed. The prepared auxetic structures were composed of two neo- Hookean materials and were further divided into homogeneous, two-layered and multi-layers structures. For two-layer and multi-layer structures, a thermal expansion simulation was performed, and with the help of the values obtained from the simulation of the cube structure, the temperature change was calculated for individual simulation states, which were randomly determined. Furthermore, stress histograms were made for prepared structures and the most frequent stress value for the given simulation state was determined. The last part consisted of determining the thermal expansion of the simulated materials. Coefficient of thermal expansion of prepared materials was calculated using data obtained during each simulation of the cubic structure of dimensions mentioned above.
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Evaluation of the quality of collagen samples in solid phase using circular dichroism
Ďubašák, Matej ; Žídek, Jan (referee) ; Vojtová, Lucy (advisor)
Diplomová práca sa zaoberá novou kvalitatívnou analýzou kolagénových vrstiev pomocou cirkulárneho dichroizmu v pevnej fáze. Teoretická časť opisuje kolagén a jeho sekundárnu štruktúru, spektroskopické metódy cirkulárneho dichroizmu (CD) a zoslabenej úplnej reflektancie (ATR). Experimentálna časť sa zaoberá prípravou homogénnych a transparentných kolagénových filmov a optimalizáciou objemu, koncentrácie a sušenia. Následne sa zmerala a vyhodnotila kalibračná krivka s rôznymi pomermi kolagénu a želatíny. Získaná rovnica lineárnej regresie sa použila na stanovenie obsahu kolagénu v modifikovaných vzorkách. Výsledky hodnotených modifikovaných vzoriek boli porovnané s meraniami ATR spektroskopie. Merania ATR ukázali vyšší obsah kolagénu ako CD merania. Vzorky s najnižším a najvyšším obsahom kolagénu sú pre obe metódy rovnaké. Dokazuje to, že môžme porovnávať vzorky s rôznym obsahom kolagénu navzájom, ale nemôžeme určiť presný obsah kolagénu pripojením týchto dvoch metód. Optimalizovaná metóda CD sa môže použiť na prípravu a meranie presného obsahu kolagénu vo vzorkách, najmä v rámci výroby kolagénu, aby sa dosiahla konštantná kvalita kolagénu v každom kroku výroby.
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Influence of Solvent on Deformation Behavior of Hydrogels
Kulovaná, Eva ; Bartlová, Milada (referee) ; Mráček, Aleš (referee) ; Žídek, Jan (advisor)
The thesis deals with molecular dynamic simulation of the influence of water on the deformation of hydrogels. Hydrogels are model materials formed from macromolecular networks solvated with water. It was found that water can form bridges between macromolecules that take the form of temporary ionic crosslinks. These bridges affect the behavior of the network during deformation. Water bridges are water molecules that have a limited radius of motion in the space between two macromolecules. The concentration of the water bridges was regulated by a partial charge on the macromolecular chain in the organic network. Bridges are a type of interaction that is relatively strong but significantly delocalized. It is not possible to dissociate the water bridge, after dissociation it will be re-created in another place in a short time. The influence of water bridges was compared with other types of network crosslinks, especially covalent and physical bonds. Covalent crosslinks are modeled as a simple binding interaction between two macromolecules. They are undissociable and are local throughout the simulation. Physical bonds are modeled as micelles, where hydrophobic groups form the core and hydrophilic groups form the micelle shell. Physical bonds have the nature of dissociable bonds that are local. Different types of crosslinks have different effects on deformation properties. The deformation of a network containing a combination of two types of crosslinks was simulated: (i) physically-covalent, (ii) ionically-covalent, and (iii) physically-ionic networks and (iv) ternary physically-covalent-ion networks. For individual and combined networks, the behavior depending on simple networks was verified. The number of water bridges was fundamentally affected by the primary structure of the chains. When the PEG chain was replaced with hydrophobic polyoxymethylene (POM) or polyoxytrimethylene (POTM), their solvation and mechanical behavior deteriorated.
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Processing of tomographic data by principal component analysis method for archaeological applications
Prokop, David ; Žídek, Jan (referee) ; Pořízka, Pavel (advisor)
Rentgenová počítačová tomografie je metoda sloužící ke 3D zobrazování vnitřní struktury objektů. Mikrostruktura objektů ukrývá důležité informace, které mohou být použity k jejich charakterizaci. Tato práce podává spojení mezi datasety získanými pomocí rentgenové počítačové mikrotomografie a oblastí statistického zpracování dat. Výstupem metody, pak bude klasifikace vzorků na základě informací o jejich mikrostruktuře. Z výsledků klasifikace vzorků, pak můžeme vyvodit různé hypotézy týkající se původu vzorků. Tato práce by mimo jiné mohla sloužit jako takový nový vhled do problematiky kombinace dat různého původu, pomocí metod statistické analýzy.
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Tocharian loanwords in Chinese
Židek, Jan ; Kim, Ronald (advisor) ; Elšík, Viktor (referee)
This work was created to review the evidence for lexical borrowing from the Tocharian languages to the Chinese languages. The used methodology relies on lexical lists, previous etymological findings, linguistic typology and anthropological input. For preparatory data manipulation, a set of semi- automatic scripts has been created. Presented is a qualitative research based on previous findings assisted by raw data. The outcome of this work should be testable findings which could be extracted to a computer processable form.
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Institutional arbitration procedure
Žídek, Jan ; Růžička, Květoslav (advisor) ; Dobiáš, Petr (referee)
vi Summary The thesis focuses on the description and comparison of the arbitration proceedings in the Czech Republic and Switzerland before local arbitration institutions. The choice of Switzerland has been influenced by the fact that this country is a traditional seat of arbitration and several arbitration institutions are domiciled there. The diploma thesis consists of an introduction, four main chapters and a conclusion. The first chapter contains a general description of arbitration and alternative dispute resolutions. Following chapters address the comparison issue outlining the arbitration regulations in both above mentioned countries and provide a thorough analysis of two major arbitration institutions. The first being the Arbitration Court attached to the Chamber of Commerce and the Agricultural Chamber of the Czech Republic which is the sole permanent arbitration court with a full jurisdiction seated in the Czech Republic. The other institution being presented is the Swiss Chambers'Arbitration Institution that, in order to administrate arbitration proceedings, introduced in 2012 a new set of rules and revised its organisational structure. Last but not least, the thesis concentrates on description and comparison of the principle arbitration stages under the current rules of both institutions. The...
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Hypostasis, Conversion, Categoriality
Židek, Jan ; Bičovský, Jan (advisor) ; Starý, Zdeněk (referee)
In modern linguistics since the 1970s, there seems to be a general shift from langue to parole and from discrete categories to more "blurry" ones. With it comes a need for revitalisation of some older terms that fell out of usage because of the fact that they describe something (seemingly) outside system. One such term is hypostasis, a synchronic phenomenon of word- formation under certain constrains (e.g. null derivation from an inflected form). This work's aim is to probe its usefulness in modern linguistics and the viability of its revitalisation. In this work, I agree with now generally accepted idea that every grammatical system is in itself inadequate with regard to completeness of its function, and that it needs from time to time adapt to new situational contexts through compensation strategies; some of the ways it does that can collectively be called "hypostasis".
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Micro-grinding applications in high precision manufacturing focusing on surface quality
Macháčová, Veronika ; Dvořák, Jaromír (referee) ; Žídek, Jan (advisor)
The object of this bachelor thesis is to write a research study dealing with micro-grinding technology. Increasing the requirements of components and dimensional accurancy (in micrometer units), further the requirement of high surface quality and the application of a wide range of difficult to process materials has led to the development of this technology as an independent field. The content is overview of the micro-grinding process with its advantages and disadvantages, used tools and their machining, micro-grinding machines and an example of aplication in various areas of industry.
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Cutting tools manufacturing for micro-milling
Tkadlec, Jiří ; Dvořák, Jaromír (referee) ; Žídek, Jan (advisor)
This bachelor work is focused on the research of the problems of micro-cutting, exactly of micro-milling and manufacturing of cutting tools. The introduction contains basic analysis of micro-milling and specification of micro-milling. The main aim of this work is analysis of the manufacturing of cutting tools and analysis of cutting tools materials used for micro-milling.
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