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Potential risks of nano-particle materials utilization
Flimelová, Miroslava ; Šmejkalová, Daniela (referee) ; Kučerík, Jiří (advisor)
The thesis „Potential risks of nano-particle materials utilization“ summarizes scientific knowledge on nanotechnology, nano-particle and nano-chemistry. The aim of the work is the literature overview on potential problems associated with their utilization. Thesis is focused particularly on nanoparticles exploitation and limits connected with their understanding and prediction of their fate in the environment. The impact of nanotechnology on the society and every-day life is discussed with respect to various risk sources.
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Preparation and Characterization of Drug Carrier Systems on the Basis of Magnetic Nanoparticles
Chvátalová, Barbora ; Burdíková, Jana (referee) ; Kalina, Michal (advisor)
This bachelor thesis deals with the study of magnetic nanoparticles, optimizing their preparation and stabilization. The nanoparticles with different ratios of Fe2+ and Fe3+ ions were prepared by coprecipitation by variously concentrated sodium hydroxide. Three samples of particles were selected and were further observed. Their stability in Milli-Q water, buffer, polyvinylalcohol, hyaluronic acid and chitosan was studied in function of time using methods of dynamic and electrophoretic light scattering. By UV-VIS spectrometry it was confirmed that the magnetic nanoparticles were actually prepared. Nanoparticles coated with chitosan and hyaluronic acid were then further characterized using FT-IR, XRD and SEM.
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A Nanocomputer Simulator Using Cellular Automaton
Kmeť, Dušan ; Bidlo, Michal (referee) ; Sekanina, Lukáš (advisor)
This master thesis deals with the realization of a simulator based on asynchronous cellular automata simulating delay insensitive circuits. In connection with nanotechnology, cellular automata have several interesting properties, such as self-replication, regular structure and high parallelism that make them very useful as models for some types of nanocomputers. This text describes the relationship between cellular automata and nanotechnology. Emphasis is given to the possibility of using asynchronous timing mode. Asynchronous cellular arrays based on asynchronous cellular automata could prove to be a suitable architecture for future nanocomputer, which was the reason for implementation of this simulator. The simulator's functionality was verified by experiments.
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Diagnostics of Diaphragm Discharge in Water Solutions and its Application for the Nanomaterials Surface Treatment
Dřímalková, Lucie ; Brablec, Antonín (referee) ; Janda,, Mário (referee) ; Krčma, František (advisor)
The exact mechanism of the discharge in liquids ignition is not sufficiently known up to now. Although during the last years was achieved the great progress and overloading which some of them are written in this theoretical part of thesis. This thesis is divided into two experimental parts. When the first part deals with diagnostics of diaphragm discharge in electrolyte solutions and the second part is focused on its use for uncoiling (higher homogenization) of carbon nanotubes in solutions. In experiment 1, three different sized (4 l, 100 ml, 50 ml) diaphragm discharge configurations were used to diagnose diaphragm discharge in electrolyte solutions. Diagnostics is done through current and voltage waveforms with the addition of synchronized ICCD camera images that have been connected to a four-channel oscilloscope. The V-A characteristic can be described by three events occurring in the electrolyte solution with a gradual increase in voltage. Slowly increasing of the voltage in the solution leads first to electrolysis. The next phase is the formation of microbubbles or bubbles, which is characteristic of the curve by a slight decrease in the increase of the current passing between electrodes. The sudden increase in the current flow is characteristic of the last phase, namely the discharge phase. The distance of the electrodes from the diaphragm does not significantly affect the V-A characteristic. The higher diameter of the pin hole, therefore, has a higher voltage, but this does not affect the origin of bubble generation or breakdown. The higher thickness of diaphragm, the higher voltage is needed to the beginning of the bubbles generation, and consequently the discharge breakdown. Comparison of the voltage of the start generation of the bubbles and breakdown for PET diaphragms and diaphragms from the ceramic there was no mark able difference. One of the most important parameters is the conductivity of the electrolyte solution. The lower voltage is needed for the start generation of the bubbles at the higher solution conductivity, and also the discharge generation is observed at a lower breakdown voltage. The second experimental part is focused on the study of the diaphragm discharge effect on carbon nanotubes. A specially designed U-shaped reactor is used to modify carbon nanoparticles. Tap water and aqueous solutions of organic compounds are used as the electrolytic solutions. The discharge is generated by a non-pulsed DC high source with a voltage in the range of 0-2.8 kV supplied to platinum electrodes located in the electrolyte solution. The experimental results have shown that the diaphragm discharge has positive effects on the disintegration of clusters and agglomerates of carbon nanotubes. The primary effect on disintegration is probably the shock waves generated by the discharge. It turned out that it depends on the electrode configuration, where the treatment in anode space has far greater effects than the treatment in cathode half of the reactor. Effects of carbon nanotubes disintegration in solution are long-lasting and the treatment effect is not loosed after several months. There were detected no significant changes in the structure of plasma-treated nanotubes by Infra-red spectroscopy.
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Flexible generators of electrical energy
Tesařová, Tereza ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bachelor thesis is focused on actual research part of energy harvesting technologies – flexible electrical generators, which mean the special generating of electricity using specific flexible materials. The net charge result is affected by the incidental mechanism to transform certain energy form into electrical power and is influenced of material range, which determines what will be harnessed as a source of energy. The energy harvesting is aiming at producing alternative and efficient ways instead of harmful and strained manufacture processing.
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Study of gas influence on nanoparticle generation by electrical discharge in liquids
Simić, Sanja ; Horák, Jakub (referee) ; Kozáková, Zdenka (advisor)
The work is focused on the preparation and characterization of Ag nanoparticles generated by plasma of the electric discharge in liquids. In more detail, it examines the DC discharge and the formation of hydroxyl and hydrogen radicals. The process is chemical in situ reduction, which is one of the most important methods of producing Ag nanoparticles because it is simple and economical and can perform better dimension size control by optimizing experimental parameters. During experiments, changes were made in various parameters such as concentration, conductivity, solution pH, intensity and polarity of the applied voltage. Different parameters such as particle size, shape, specific surface, crystallinity and many others can affect the properties of the nanoparticles. In view of these facts, detailed analysis of both plasma and nanoparticles generated for the control of nanoparticle synthesis and subsequent application is essential. In this work a plasma analysis was performed by optical emission spectroscopy (OES) and the characteristics of nanoparticles by UV-VIS spectroscopy and scanning electron microscopy (SEM). Silver nanoparticles are used in many industries such as the food, textile, construction and energy industries as well as in medicine, cosmetology and pharmacy. Thanks to their widespread use they represent the future of nanotechnology.
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Thermal aging of nanocomposites
Janíček, Martin ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
This thesis deals with issues of properties of nanocomposites and it´s heat aging. In the first part there are theoretically analysed some of the basic therms connected with nanocomposites. Also there are outlined basic methods of production of these matherials. The most important is specification of individual properties when bigger attention is gived to electrical properties. Practic part deals with heat aging of samples of nanocomposites filled with nanoparticles Al2O3. There was monitored impact of time of aging on values of internal resistance, dissipation factor and relative permitivity.
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Nanostructured sensors for detection of organic compounds
Šťávová, Karolína ; Fohlerová, Zdenka (referee) ; Hrdý, Radim (advisor)
This bachelor's thesis is focused on the fabrication of sensitive layers composed of an array of gold nanorods and their modifications. Firstly, a nanoporous mask is made from a layer of aluminum using a method called anodic oxidation. Afterwards electrochemical deposition of gold and polypyrrole or gold and mercury is carried out into the mask. The sensitive layer is characterized by the scanning electron microscopy and other methods for elemental analysis. A sensor with this type of sensitive layer can be used for the detection of various organic compounds.
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Gold nanoparticles as a tool of targeted therapy of cancer
Knoblochová, Lucie ; Hodný, Zdeněk (advisor) ; Brábek, Jan (referee)
Nanomaterials have caught the interest of biomedical science because of their size (which enables them to interact with cellular structures), high surface area, and unique physical properties. Gold nanoparticles (GNPs) can be synthesised in various shapes. Their common property is surface plasmon resonance, which makes it possible to detect these particles with high resolution using dark field microscopy. GNPs can be efficiently modified with various ligands such as drugs, antibodies, or aptamers; this can be utilized to selectively bind GNPs to tissues, e.g. for drug delivery. Conjugated GNPs can also be used in diagnostics of tumor cells as well. Photothermal therapy consists of GNPs selectively binding to the tumor tissue, where they transform light into heat upon irradiation by near-infrared (NIR) light, thereby damaging nearby cells. The toxicity of GNPs is currently unclear. Research into modified gold nanoparticles is of great interest for targeted tumor therapy, as it may yield a tool for the selective destruction of tumor cells.
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