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Properties and application of ferrofluids
Vaverka, Jakub ; Šedivý, Dominik (referee) ; Zbavitel, Jan (advisor)
Ferrofluids are substances that can change their properties through an external magnetic field. The theoretical part of this bachelor thesis explains the nature and properties of these liquids, and how they are made. The next chapter provides concrete examples of ferrofluid use, and where it is possible to direct current research. The principal objective of the experimental part is to measure and evaluate the surface tension of two different samples of kerosene-based ferrofluids.
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Investment casting waxes and measurements of their properties with regard to simulation software
Bochníček, Štěpán ; Mikulka, Vít (referee) ; Kosour, Vojtěch (advisor)
Today, the use of simulations is increasing in order to reduce cost and complexity of production and also to prevent product defects. For this purpose, we use simulation programs, such as ProCAST. This program is designed for simulation of casting parts. In my bachelor thesis I focused on the methods of casting lost wax, where the model is made of wax mixture. In each simulation we have to obtain and specify the properties of the material to casting. I described these properties and methods of measurement in this bachelor thesis.
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Deposition and characterization of SA layers from vinyltriethoxysilane
Veverka, Miroslav ; Veselý, Michal (referee) ; Čech, Vladimír (advisor)
Development of composite material is very much progressive sector and leads to evolution of material with new property. This type of material has one, but important deficiency. It is small adhesion armature to matrix. My study is sight on improvement adhesion the surface by deposition self assembled (SA) monolayer from organosilanes. Property of this layer, like thickness, surface tension, homogenity and wettability, was evaluated by the contact angle measurement and spektroscopical elipsometri.
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Theranostic systems in sonography
Říkovská, Klára ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
This work deals with preparation of microbubble suspension from a mixture of phospholipids, palmitic acid and polyethylene glycol. Properties of prepared systems were studied using bubble tensiometry and dynamic light scattering method and were compared with commercial contrast agent SonoVue®. Suspensions were prepared in various conditions including different atmosphere and increased temperature in some steps of preparation and different solution. Effect of polyethylene glycol addition on surface activity of the system was studied. Surface activity of phospholipids was insignificant. Surface tension decreased with increasing concentration and molecular weight of polyethylene glycol in the system. Effect of different atmosphere and increased temperature showed no substantial trend. It emerged that dynamic light scattering is not suitable for this type of samples because of high polydispersity and phase separation of the system.
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Surface tension measurements
Hála, Ondřej ; Vimmr, Jan (referee) ; Košťál, David (advisor)
The thesis deals with study of surface tension of liquids and measuring possibilities of this parameter. The paper is then focused on design of measuring apparatus based on pendant drop method. The apparatus is controlled with software written in Matlab. Several measurements are done at the end of this work, which confirm possibility to practical use of this apparatus for surface tension measurements. A part of this work is manual to use the apparatus and complete design documentation.
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Insulation and dielectric properties of water
Grill, Jiří ; Frk, Martin (referee) ; Špinka, Jiří (advisor)
This master´s thesis deals about insulation and dielectric properties of water. It describes the structure of water, covalent and hydrogen bonds. It outlines primary chemical and physical properties of water and then it describes parameters of water - dynamic viscosity, conductivity, surface tension, pH and also describes dielectric properties - dielectric loss, loss factor, permittivity, polarization. Part of the work is practical section, which includes measurements of deionized water, destilled water, tap water and shows primary dependence such as dependence loss factor on frequency or relative permittivity on frequency.
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Dynamic surface tension in study of hyaluronan-surfactant interactions
Herzog, Milan ; Žídek, Jan (referee) ; Pekař, Miloslav (advisor)
The main task was to characterize interactions between negatively charged biopolymer sodium hyaluronate and two cationic surfactants: cetyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB). Interactions between sodium hyaluronate and these surfactants are based on their different charge and can be detected by changes of surface tension. The influence of constant addition of sodium hyaluronate (MW = 90 and 1400 kDa) on interface tension values at increasing bubble lifetime was observed. For this purpose, the maximum bubble pressure method was choosen. The measurements were performed in water and in 0,15 mol•l-1 NaCl solution. The obtained results can be used as for description of dynamic properties of hyaluronate-surfactant systems as, e.g., in targeting drug delivery.
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Minimum head of triangular-notch thin-plate weir
Vicena, Dušan ; Žoužela, Michal (referee) ; Zachoval, Zbyněk (advisor)
The bachelor´s thesis consists of research and experimental part. The content of research part is the description of the overflow height of thin-plate weir with triangular notch, description of surface tension and overview of literature dealing with measuring of overflow height of thin-plate weir. Experimental part contains the description of the experimental equipment, process of measurement and results of experiment. The results are evaluation of measured values and determination dependence of minimal overflow height on the angle of triangular notch and comparison with formulas given in scientific literature.
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Discharge coefficient of slit weirs
Havran, David ; Žoužela, Michal (referee) ; Zachoval, Zbyněk (advisor)
This work deals with experimental research, with outcomes of design and recommendation for determination of the discharge coefficient of the slit weir. At the same time states the possible effects on capacity. Then comparing the data with already existing ones. The thesis provides an overview and insight into the meaning of slit weirs as well. The goal is to recommend the determination of the discharge coefficient.
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Properties and application of ferrofluids
Vaverka, Jakub ; Šedivý, Dominik (referee) ; Zbavitel, Jan (advisor)
Ferrofluids are substances that can change their properties through an external magnetic field. The theoretical part of this bachelor thesis explains the nature and properties of these liquids, and how they are made. The next chapter provides concrete examples of ferrofluid use, and where it is possible to direct current research. The principal objective of the experimental part is to measure and evaluate the surface tension of two different samples of kerosene-based ferrofluids.
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