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Study of durability of FRP reinforcements
Dipold, Václav ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
This thesis deals with monitoring the durability of FRP reinforcement in different types of environments which cause degradation. The theoretical part of the thesis describes reinforcing fibers, matrix materials, manufacturing technology of composite reinforcements by pultrusion and durability of FRP materials in environmental degradation. In the experimental part of this thesis was carried storing samples reinforcements in alkaline environment with various temperatures. As suitable were selected temperatures of 20 °C, 40 °C and 60 °C. Subsequently are described changes in physical properties of the reinforcements and tracking optical microscope.
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Study of optoelectrical properties of organic semiconductor thin film layers of phtalocyanines
Miklíková, Zdeňka ; Vala, Martin (referee) ; Zmeškal, Oldřich (advisor)
Diploma thesis is focused on the study of optoelectric properties of thin layers of organic materials based on phthalocyanines, which can be used as an active layer of photovoltaic cells. Especially are studied the properties of the thin active layers of PdPc and PdPc + IL on the glass or ceramic substrates with aluminium contact, which are prepared by material printing here. On the prepared samples were first measured current-voltage characteristics in the dark and in the light and then were measured impedance spectrums in the dark. The received results will be used to improve the properties and structures of photovoltaic cells.
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Study of emulsion stability by means of physical-chemical and optical methods
Kuchyňová, Jitka ; Veselá, Mária (referee) ; Zmeškal, Oldřich (advisor)
The diploma thesis deals with the stability determination of model O/W (30/70) emulsions at 25°C. In fact, the time and emulsifier concentration (Tego Care PS) dependences of physical properties (aging) were monitored. In the second part of the work, the influence of conservant on emulsion stabilities were studied. In order to study physical properties of emusions rheometry, differential scanning calorimetry (DSC) and optical microscopy were employed. The rheological measurement provided information on viscosity and viscoelastic modulus. DSC experiments used the repeated freezing/thawing cycles which allowed monitoring of changes in crystallization temperature of water present in emulsions and melting enthalpy of ice formed during the cooling. The optical microscopy was used to examine the change in oil droplet size in the course of emulsion destabilization and phase separation. In this case the image analysis was carried out using program HarFA. The results showed that due to the emulsion creaming, the oil droplets diffuse and aggregate which causes phase separation. Those processes were quickest for the emulsion with lowest emulsifier concentration 0.1 % (destabilization during 51 days) The emulsions with emulsifier concentration about 1.5 and 1.3 % were stable at least for 4 months. The presence of the coemulsifiers increased the elastic modulus and descreased the phase difference due to the network formation. It was shown that for the stability determination is necessary to use conservant due to risk of microbial contamination. DSC experiments allowed to distingush samples prepared under different conditions. Lower rotational speed during emulsion preparation caused the appearance of two melting and crystalization peaks while for higher speed only one peak was observed.
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Use of biomaterials for optoelectronic applications in semiconductor technology
Čuboň, Tomáš ; Salyk, Ota (referee) ; Zmeškal, Oldřich (advisor)
The bachelor´s thesis is aimed to measurement optical properties of thin layer films of biomaterials which could be used in optoelectronics and semiconductor technology. DNA and BSA were chosen in order to represent such extensive group of biomaterials. The theoretical part describes the way of preparation of thin layer. It also provides some information about basic phenomena and biomaterials. The practical part is focused on the description of preparation of thin layer film using spin-coating method. The chosen materials were studied by optical microscopy, UV-VIS spectrophotometry and spectroscopic ellipsometry. The thickness of prepared samples was measured by mechanic profilometry. In the last section of the bachelor´s thesis, there is discussion and evaluation of results.
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Preparation of graphene layers by various methods and characterization of their properties
Zahradníček, Radim ; Bartošík, Miroslav (referee) ; Lišková, Zuzana (advisor)
This bachelor's thesis deals with the production of graphene by different methods. Graphene was prepared by mechanical exfoliation and chemical methods. Graphene oxide (GO) was first prepared by modified Hummers method and disolved the solution in isopropyl alcohol. It was subsequently reduced by photoreduction, UV radiation and thermal reduction. Produced graphene samples were characterized using optical microscopy, electron microscopy, atomic force microscopy, Raman spectroscopy and X$-$ray photoelectron spectroscopy. Measurement results and evaluation of production quality of graphene are shown in this work.
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Methodology of Dictyostelium discoideum imaging with the transmission digital holographic microscope
Křížová, Aneta ; Ježek, Jan (referee) ; Uhlířová, Hana (advisor)
The task of this bachelor’s thesis was to image Dictyostelium discoideum with a transmission digital holographic microscope and compare this imaging with a commonly used microscopy technique. This bachelor's thesis is structured into a theoretical part and an experimental part. The theoretical part describes the setting of the transmission digital holographic microscope, basic operation and physical principles of imaging with this microscope. Further the process of image reconstruction and numerical process of phase reconstruction is illustrated. At the end of this part, basic biological characteristics of observed cells of Dictyostelium discoideum are introduced. The experimental part describes the cultivation and preparation of Dictyostelium discoideum for the observations, and further the process of performed experiments. The cells of Dictyostelium discoideum have been imaged in couple experiments by a method of the classical phase contrast. By the transmission digital holographic microscope the cells of Dictyostelium discoideum have been imaged in two mediums. Images captured by the transmission digital holographic microscope were processed by a method of Dynamic phase differences and analysed.
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User programme for imaging and visualization of quantitative phase from the digital holographic microscope
Hladík, Lukáš ; Kvasnica, Lukáš (referee) ; Uhlířová, Hana (advisor)
This bachelor thesis deals with creation of an user computer program for processing of phase contrast images from a digital holographic microscope. The theoretical section of the thesis contains basic information about obtaining and evaluation of processed images, including a description of their digital representation in the computer. The experimental part deals with techniques and algorithms on which the program is built. This part also contains a description of the graphical user interface of the program and evaluate the impact of different user settings for output files properties.
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Mesoporous and microstructured layers of titanium dioxide
Lepičová, Martina ; Ing. Viera Jančovičová,Ph.D. (referee) ; Veselý, Michal (advisor)
This bachelor thesis provides an overview of modern ways of titanium dioxide thin layer preparation including material printing and their principles. Preparation of tetrabutoxide sol as a precursor of titanium dioxide with diethanolamine and polyethylene glycol as templating agents and its delivery to glass substrate by material printing is described. This work is focused on characterization of prepared thin layers of titanium dioxide by optical microscopy and making of microphotography database of prepared samples.
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A method for the visualization of high phase gradients in a microscopic image
Druckmüllerová, Hana ; Martišek, Dalibor (referee) ; Chmelík, Radim (advisor)
Holografická mikroskopie je nekonvenční mikroskopická technika, vhodná zvláště pro vzorky s malou optickou hustotou, která umožňuje zviditelnit index lomu pozorovaných objektů. Na Ústavu fyzikálního inženýrství Fakulty strojního inženýrství VUT v Brně byl sestrojen unikátní transmisní digitální holografický mikroskop (TDHM). Pořízené snímky (hologramy) jsou zpracovány metodou založenou na Fourierově ransformaci, čímž je zrekonstruována intenzita a fáze světelné vlny procházející pozorovaným objektem. Fáze popisuje index lomu a tloušťku pozorovaného objektu. V místech, kde se mění index lomu nebo tloušťka, dochází i ke změně fáze. Úkolem této bakalářské práce bylo najít metodu pro zviditelnění míst s vysokým gradientem fáze. Podařilo se vytvořit metodu, která nevyžaduje navazování fáze, a proto je vhodná pro libovolné obrazy pořízené TDHM. Tato metoda byla implementována do počítačového programu Gradient3D, který kromě výpočtu gradientu ve dvou a třech rozměrech umožňuje i vytváření barevných obrazů, jejichž složkami jsou kombinace intenzity, fáze a gradientu. Program též umožňuje odstranění falešných gradientů v místech s nízkou intenzitou, kde je hodnota fáze nespolehlivá. Program byl testován na několika souborech hologramů pořízených TDHM při pozorování biologických vzorků.
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Microscopy - Point Spread Function, Focus, Resolution
NÁHLÍK, Tomáš
The aim of this thesis was to design new algorithms for processing image data from microscopes and demonstration of the possibilities of their use on standard samples (latex particles of different diameter). Results were used for the analysis of real objects inside the living mammalian cell. For the design of these algorithms was necessary to first understand how the image in the microscope is build, including a variety of lens aberrations. It was necessary to start with simulations of ideal case displaying one point (simulation PSF). Images of Airy discs in the plane of focus, or simulations using the ENZ theory. Available ENZ simulations provide only a few sections of different focal planes. It was necessary to adjust them to a usable form for generating a full 3D view. Using these algorithms, it was examined the behavior of the basic lens aberrations, and the behavior of two particles (objects) at different distances from each other. At the conclusion of these observations, it was necessary to redefine the terms Focus and resolution. Furthermore, the definitions have been introduced for discriminability and distinguishability of objects in an image. Thanks to the new definitions and new viewing (information entropy) to challenge the discriminability/distinguishability problem of objects in the image was possible to design and develop algorithms for image processing that enable to detect objects below the Abbe resolution condition using standard optical bright field microscopy. It has been found experimentally that the limiting factor for resolution using this method is the size and resolution of the camera chip. When using a chip with a higher density of points, we can achieve better results (detection of smaller objects) using the same algorithms.
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