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Verification of the properties of concrete with carbon nanotubes
Kutová, Lenka ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis deals with monitoring the properties of concrete with carbon nanoparticles. The theoretical part describes properties of nanoparticles, their dosing and dispersion. In the practical part of the diploma thesis the physico-mechanical properties of the concrete with the addition of carbon nanotubes were determined after 7 and 28 days of aging. The frost resistance test was then determined after 100 cycles. All results were compared with the reference samples.
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Effect of flexural loading on electrical properties of alkali-activated slag composites
Šimko, Lukáš ; Kusák, Ivo (referee) ; Rovnaník, Pavel (advisor)
Ordinary concrete is the most commonly used building material, but nowadays the requirements for low energy consumption, durability of structures together with their easy diagnostics as well as ecological production raises. This thesis deals with cement and aluminosilicate composites with content of conductive fillers, which allows to monitor the change in electrical properties, most commonly electrical resistance in dependence on mechanical stress. In the experimental part of the thesis, test beams were produced based on alkali-activated slag with content of carbon nanotubes, graphite powder, carbon black and carbon fibre. The beams were subjected to flexural loading in a three-point bending configuration and the shift in electrical resistance was monitored.
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Tip modification for high-resolution AFM imaging of nanostructures
Faitová, Hana ; Matolínová, Iva (advisor) ; Vorokhta, Mykhailo (referee)
Atomic force microscopy (AFM) is a young and widely used method of ima- ging surface, nanostructures, biological and other sensitive objects using sharp tip on a flexible cantilever scanning the sample surface. When operating in air it reaches resolution of about several nanometers. The resolution is mainly depen- dent on the used tip. The thesis deals with modification of old tips by carbon nanotubes (CNT) in scanning electron microscope (SEM) using techniques inclu- ding focused ion beam (FIB) and gas injection system (GIS). Several procedures of CNT sample preparation and attaching the CNT on tip are presented. The functionality of modified tips was checked in AFM using the calibration sample consisting of well-defined nanostructures. 1
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The issue of the use of carbon nanotubes in cement composites
Pacltová, Klára ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with the analysis of the efficiency of carbon nanoparticles in cement composites. The theoretical part of the bachelor thesis is focused on the research of information about carbon nanotubes and their influence on cement composites. The practical part follows the research of the theoretical part, where is verified the effectiveness of carbon nanotubes in cement composites at different dosages.
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The issue of concrete resistance to high temperatures
Krejčík, Jakub ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Bachelor´s thesis deals with resistance of cement concrete to high temperatures. Theoretical part of bachelor´s thesis describes changes that occures in concrete at thermal loading and behavior of each component of concrete. Next there were discribed ways to improve resistance of concrete to high temperatures, by choosing the right component or by adding fibre reinforcement. In experimental part composites with bassalt and polypropylen fibre and with bassalt aggregates were tested. In these composites changes of compressive strenght and changes of density were mesured according to the thermal loading. Next individual fibre reinforcement polypropylen, celulose and bassalt fibres were exposed to the thermal loading and their changes were observed.
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Detection of Oxidative Stress Using Electrochemical DNA Biosensors
Jurečková, Zuzana ; Vyskočil, Vlastimil (advisor) ; Fischer, Jan (referee)
Presented Diploma Thesis is focused on the development, characterization, and utilization of simple and inexpensive electrochemical DNA biosensor for the detection of DNA damage caused by oxidative stress. The initial part of the work is devoted to preparation and characterization of a large-surface carbon film electrode (ls-CFE) modified with carbon nanotubes (CNT/ls-CFE). Carbon nanotubes improve electrochemical properties of the transducer and increase the amount of adsorbed DNA on the electrode surface. Testing of the electrode surface modified with multiwalled carbon nanotubes (MWCNT) was performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using a redox system [Fe(CN)6]4-/3- and using square wave voltammetry without any redox indicator. Carbon nanotubes have proved to be unsuitable material for our type of biosensor, but it can be used inanalytical chemistry for the determination of electroactive substances. The second part of this Thesis deals with the application of the prepared DNA biosensor for the detection of DNA damage by oxidative stress. The biosensor based on the ls-CFE was chosen for this purpose, having several advantages, such as its fast preparation, a simple mechanical renewal of the electrode surface, a good reproducibility of measurements,...
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Prerequisites for building magnetometer out of carbon nanotubes for geological applications
Mazanec, Martin ; Kletetschka, Günther (advisor) ; Kohout, Tomáš (referee)
This thesis is the first step in a long-therm project with object to built magnetometer from carbon nanotubes. At the beginning of the thesis is introduction to magnetism and its basic physical characteristics, brief description of the Earth's magnetic field, some magnetic minerals and material behavior in a magnetic filed. All this in a geological context. In the second part I focus on the measurment of the magnetic field, especially on some specific device. The third part deals with the allotrope of carbon - graphene structures. It offers a brief overview of thein properties, one chapter about the productiona and possible use. In discussion I try to combine these parts with a specific purpose, which is the uso of carbon nanotubes in measuring the rock magnetism. We present a simplified funcion principle of the discussed device, the first steps of construction and inicial measurment.
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Carbon nanomaterials and their interactions with bacteria
Jurková, Blanka ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Recently, carbon nanomaterials gain attention especially for their interesting, often unique, properties. They can be used in wide range of applications, such as electronics, optics, cosmetics, solar cells, construction materials, air filters, polishing materials, protective coatings and dry lubricants. Whereas their physical and chemical attributes have already been intensively examined, the research on their effects on living organisms is still at the preliminary stage. This work is focused on the interactions of carbon nanomaterials, namely graphene, fullerene, carbon nanotubes and nanodiamonds, with bacterial cells and their antibacterial and antiadhesive properties. The mechanisms of the toxic action of carbon nanomaterials against bacteria include damage of outer cell structures as a consequence of the direct contact with a nanomaterial, impairment of bacterial metabolism or reactive oxygen species production. Exact understanding of the processes that take place between bacterial cell and carbon nanomaterials can contribute to the research on their medical applications and ecological recycling in the future.
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Study of concrete properties with nanoparticles
Michnová, Kamila ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis discusses the basics of nanotechnology as a science and nanotechnology of concrete. Additionally, it describes carbon nanotubes and the possibilities of their dispersion using high shear mixing and sonication. This thesis further provides findings about ultrasonic dispersion parameters and characteristics of materials with the addition of carbon nanotubes. The experimental of part of this thesis focuses on the possibility of dispersing carbon nanotubes, deals with the issue of incorporating carbon nanotubes into the concrete matrix and describes its effects on the final properties of concrete. It has been observed to which extent the carbon nanotubes may affect selected physico-mechanical properties and durability of concrete.
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