|
|
Investigation of nanomaterials for their nuclear power and research utilization
Jelínek, Martin ; ČEZ,, Jiří Skalička, (referee) ; Katovský, Karel (advisor)
This bachelor thesis provides a comprehensive overview of the properties of various nanomaterials and summarizes the latest findings and knowledge of advanced applications in all sectors of nuclear power engineering from construction materials through nuclear fuel, fuel cladding, neutron moderator and coolant to the advanced methods for detection of ionizing radiation ad its direct utilization for electricity production. A significant space is devoted to the applications in safety systems of nuclear power plants. The experimental part of the thesis deals with the possibility of using carbon nanofibers as an additive to the coolant in VVER reactor type in order to improve the thermal properties of the coolant. So far a very little examined issues of neutron balance changes due to interaction with nanoparticles was experimentally verified on the paraffin wax mixture of two different concentrations. The comparison with the reference sample of pure paraffin was also made.
|
|
|
Molecular Communication in Nano-networks Utilizing Diffusion Process
Kupka, Lukáš ; Mašek, Pavel (referee) ; Hošek, Jiří (advisor)
The bachelor thesis is focused on theoretical desription of diffusion-based molecular communication in nanonetworks, description of simulation framework N3Sim and building a model of nanocommunication in this simulator. Second part of thesis is focused on molecular communication based on electromagnetic waves. In this case simulator NS-3 and Nano-Sim module has been used. Practical part contains detail analysis of simulators adjustment and results of simulations. Simulations are performed with different settings in several scenarios. Their comparison and results is summarized in conclusion.
|
|
|
Degradation of nanocomposites
Polách, Ondřej ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present work deals with the electrical properties of nanocomposite materials. Samples for the practical part consisting of epoxy resin as matrix and SiO2 as nanofillers and were made in four different percentage performance. There is investigated the influence of thermal degradation of nanocomposite materials change resistivity, loss factor and relative permitivity.
|
|
|
Electrochemical etching of silicon
Vrzal, Pavel ; Voborný, Stanislav (referee) ; Šamořil, Tomáš (advisor)
The electrochemical etching is very used technique for semiconductor materials modification. Different structures which find applications in many fields (biotechnology, nanotechnology or electronics) can be prepared by this technique. The task of bachelor’s thesis was preparation of porous silicon using electrochemical etching. At first, a study dedicated to porous Si was carried out. Experimental part of this work deals with a design of etching cell which was used for preparation of porous silicon by electrochemical etching. In addition, the porous Si was prepared by metal assisted chemical etching. Subsequently, created structures were analyzed by scanning electron microscopy. Photoluminescence properties of porous silicon were studied as well.
|
|
|
Trends in Solder Paste Area and Nanoparticles Influence
Dosedla, Milan ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis deals with novel trends in solder paste technology. It focuses on nanoparticle applications used as a tool for improving a state of the art lead free solder alloys. The recently published results about the impact of different types of nanoparticles on properties of newly-emerged nanocomposite solders are discussed and summarized in the thesis. Preparation, practical application and testing of new solder paste based on low temperature SnBi alloy with an admixture of titanium dioxide are also discussed. Finally, properties of solder joints using these solder pastes are investigated and the results are evaluated.
|
|
| |
|
|
Advanced ceramics for tissue engineering
Vojtíšek, Jan ; Koplík, Jan (referee) ; Bartoníčková, Eva (advisor)
This bachelor´s thesis deals issues of ceramics materials suitable for tissue engineering. An artificial substitute for human tissue can be divided to several generations. This include inert, bioactive and bioresobable materials. Resorbable substitutions are prepared from materials, which could substitute host tissue, for example hydroxyapatite. HA can be prepared in different ways (dry and wet way). To better application in medicine, ceramics foams prepared by in situ foaming or replication technique are using. Experimental part of this paper deals preparing of hydroxyapatite powder and process optimization. Samples was characterized by IR and Raman spectrometry, XRD analysis and particle size was studied by SEM. Ceramics foams was prepared by in situ foaming from Al2O3, HA and composites (in ratio 50 – 50, 75 – 25, 90 – 10). Porosity was evaluated by stereomicroscope, density and level of sintering was studied by SEM microscopy.
|
|
|
Study of interactions of biomaterials with human cell cultures.
Maslonková, Ivana ; Kostovová, Iveta (referee) ; Márová, Ivana (advisor)
The bachelor thesis was focused on introducing of techniques of cultivation of human cells in vitro and optimization of their uses in variety of cytotoxicity tests. Further, in this work were studied also interactions of cells with biomaterials and prepared organic-inorganic nanoparticles. In the theoretical part the basic conditions of cell cultivation, the characteristics of keratinocytes as cell cultures, basic characteristics of particles and also short search about the most used tests of cytotoxicity on various cells systems were described. The experimental part was focused on the optimizing the preparation of silver particles, where maltose was chosen as the most appropriate reduction agent. The average size of these prepared particles was 35 nm. The possibility of preparation of combined organic-inorganic particles including liposome particles, PHB particles, alginate particles and chitosan particles was also tested in the thesis. Later, the silver nanoparticles were encapsulated into these organic-inorganic particles as an inorganic component. The liposome particles prepared by ultrasound were evaluated as the most stable of all the other prepared particles. Human keratinocytes were chosen as the cell cultures that were needed for the observation of the particle interactions with human cells. In this work basic methods of cell cultivation and passage were introduced. Conditions of experimental work in cell culture laboratory were setting and possible application of cell cultures to cytotoxicity testing by MTT was tested.
|
|
|
Concretes with high temperature fly ash activated by nanoparticles.
Labaj, Martin ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
The aim of this thesis is to summarize the knowledge regarding reduction of negative impact of high volumes of fly ash in HVFA concretes using nanotechnology and experimentally verify the findings. To compensate the inferior early-age properties, it is possible to use active nanoparticles, such as nanosilica or nanolimestone. The first step of the experiment was the production of stable nanoparticle’s dispersions using ultrasonic homogenization and UV/Vis spectroscopy. In subsequent steps the influence of nanoparticle’s presence on cementitious materials’ properties was verified on cement pastes and mortars with 40 a 60 % of fly ash. The best variant was then used to produce nano-modified HVFA concretes. Even at a minimum dose, the positive effect on early-age properties indicates the usefulness of nanoparticles in technology of concrete. An important contribution of this thesis is also the acquired knowledge related to the nanoparticle’s behavior and handling.
|
|
|
Electrode Active Materials for Lithium-Ion Accumulators
Čech, Ondřej ; Oriňáková, Renáta (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
This doctoral thesis deals with synthesis and characterisation of electroactive electrode materials for li-ion batteries and accumulators. The work is divided into two main parts. One deals with LiFePO4 based cathode composite electroactive material and in the second is described the synthesis and utilization of monoclinic TiO2(B) as an anode for li-ion cell. The main aim of the work is to relate the synthesis procedure and structural properties of both materials to its electrochemical preformance.
|
guest ::
