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Reaction synthesis of bulk Fe-Al intermetallic materials
Dyčková, Lucie ; Hutařová, Simona (referee) ; Jan, Vít (advisor)
Bachelor’s thesis deals with iron aluminides. In literature analysis are the best known and the most widely used intermetallics materials, diffusion and other possible processing technologies of intermetallic materials. In experimental part was used sprayed coating. This sprayed coating was produced by cold gas-dynamic spray. In this thesis were analysed changes in microstructure of iron aluminides depending on annealing temperature. This thesis contains photographs of microstructure and analyses from electron microscopy and measurement of microhardness.
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Transport properties of humic gels
Sárová, Michaela ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
This bachelor’s thesis is focused on study of transport properties of humic gels. For research of these properties was used diffusion method of organic dyes in diffusion cells which is based on spectrophotometric monitoring of concentration changes depending on time. Dyes used in the experiment were specifically methylene blue and rhodamine 6G and diffusion experiments were performed on an agarose hydrogel without the addition of humic acid, with the addition of unmethylated humic acid and then with the addition of methylated humic acid. The aim of this thesis was to investigate the effects of interactions between diffusing dye and the particular type of gel to the resultant effective diffusion coefficient of dye. It has been found that the presence of humic acid in agarose hydrogel greatly influences the transport of dyes.
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Selected Fractal Algorithms and Their Use
Michálek, Bedřich ; Španěl, Michal (referee) ; Herout, Adam (advisor)
To read up on the problems of fractal algorithms, to program a simple demo application of this algorithms and propose alternatives of a further study was the goal of my project. Since the subject of fractals and fractal algorithms is very extensive, I concentrated on three specific types of them - the Mandelbrot set and the Julia sets related to it, iterated function systems with application of different algorithms for generating, and the stochastic fractals and their utilization for grass, shrub and plasma modelling. I tried out for a certain rate of their optimalization, acceleration and the comparison of time and memory requirements in my study and application although it is not ever possible due to the characteristic of the given fractal type. I also theoretically present some utilization options of the SSE technology for the acceleration of fractal algorithm calculations. The demo application is proposed in the very easy way because there was not the goal to programme a new carefully worked-out software, but rather to try to implement the read up algorithms. For this reason I focused on the clear implementation of these algorithms to be their utilization easily possible. The application is written in C/C++ language with SDL library used to handle the graphics output.
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Reaction synthesis of bulk intermetallic materials from kinetic spraying deposits
Stejskal, Pavel ; Roupcová, Pavla (referee) ; Jan, Vít (advisor)
This work deals with issues of preparation of intermetallics based on iron, nickel and titanium aluminides. It works with an idea of preparation of bulk material by reaction synthe-sis from kinetic spraying deposits by cold spray. Theoretical part is concerned with phases and compounds of these aluminides for structural applications, their characteristics and present fabrication. In experimental part there are studied microstructures created by annealing of deposits.
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Barrier properties of hydrogels
Královič, Michal ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
The main objective of this thesis is to judge the barrier properties of hydrogels. It was examined in total six kinds of agarose hydrogels, of which five kinds of gels was enriched with humic acids isolated from various sources. Humic acids were selected from IHSS standards, specifically Leonardite, Elliott Soil, Suwannee River, Pahokee Peat and Nordic Lake. Using UV-VIS spectrometry, copper ion concentrations were used to serve as a diffusion solution. Results of diffusion coefficients were evaluated by several diffusion methods. The method of diffusion in the plane of the board and three possible diffusion solutions of the constant source were used.
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Reaction synthesis of bulk intermetallic materials in Ti Ni system form kinetic spraying deposits
Dyčka, Martin ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
Bachelor’s thesis deals with intermetallic compounds which are formed in nickel-titanium binary system. The theoretical part of this thesis deals with the best known titanium based intermetallics, diffusion and possible processing technologies of intermetallic materials. In experimental part, a nickel-titanium coating created by cold spray technique was used. The changes in microstructure depending on annealing temperature were analysed. The results contain photographs of microstructure and fractures, values of microhardness and results of chemical analyses.
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Study on Reactivity of Cationic Biopolymer by Simple Diffusion Techniques
Tesařová, Barbora ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis is focused on study of chitosan reactivity by simple diffusion processes realized in hydrogel media based on agarose. Mechanical properties studied by oscilatory measurements and the pore size were determined at agarose gels with the addition of chitosan as the main parameters influenced the transport properties. The main goal of this work is the investigation the reactivity of chitosan. Agarose is used only as a supporting matrix for the formation of a hydrogel. The state of the art is aimed primarily on the study of chitosan reactivity based on already published scientific papers.
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A method for the solution of non-spherical (fiber) particles deposition by means of the Fokker-Planck equation for ODF in a laminar flow
Kopečková, Barbora ; Knotek, Stanislav (referee) ; Jícha, Miroslav (advisor)
The Bachelor's thesis deals with a deposition efficiency for a fibers by various mechanisms of a deposition. It explains deposition efficiency by diffusion, by sedimentation and by impaction. The implementation of Peterlin's analytical solution for calculation of the ODF, which is used for individual efficiencies solution, is also mentioned. Afterwards, the thesis summarizes formulas for calculation of particular efficiencies derived for spherical particles and recomputation appropriate parameters for fibers. The purpose of the thesis is to create graphs, which illustrate deposition efficiencies dependence by various mechanisms on the aspect ratio of fibers. Another goal is the graphs creation, which shows juxtaposition for various breathing modes for given deposition mechanisms. The software MATLAB is used for the whole calculation process and graphs plotting.
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Transport Properties of Thin Films Based on Polyvinylalcohol
Blažková, Dominika ; Smilek, Jiří (referee) ; Kalina, Michal (advisor)
This bachelor thesis deals with the optimization of the preparation of hydrogel thin films based on polyvinyl alcohol (PVA). The first step was to optimize the preparation of films. PVA, with a molecular weight of 130 kDa, was used for the preparation of films and 10 wt.% solutions in ultrapure water were prepared from it. The heating duration time of the solution was set at 1.5 h at 90 °C. This was followed by drying at 50 °C for 24 h. Subsequently, PVA films were also prepared from solutions of methylene blue in water and from solutions of methylene blue in an aqueous NaCl solution. The prepared films were subsequently characterized by measuring their thickness, swelling ability, specific surface area and diffusion properties. The morphology of the PVA films was also visualized by SEM microscopy. All prepared films were smooth and had a very small specific surface area. The transport properties were monitored by the method of release into solution and Methylene blue was used as a probe. Release into 5, 10 and 20 ml of ultrapure water was observed. The results obtained show that the most methylene blue was released into the solution with the greatest volume and the release of methylene blue from the PVA film takes place freely without significant interaction with the matrix of the PVA film.
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