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Plazmochemické odstraňování korozních vrstev bronzu / Plasma chemical removal of bronze corrosion layersMiková, Petra January 2019 (has links)
The thesis deal with applying low-pressure low-temperature plasma to corrosion products layers on bronze. Layers of corrosion products on samples were artificially prepared. As a result, they had the same composition and could be irreversibly destroyed during experiments, which would not be possible with real archeological artifacts. Bronze, copper and tin alloy, samples were cut with respect to the size of the plasma-chemical device. XRF was used to determine the bronze composition. Before being corroded by the active medium, each sample was washed with ethanol and dried with a hot air stream. Until now, the procedure was the same for all samples. During formation of corrosion products layers, two factors have to be taken into account: the time consumption and the corrosiveness of the active environment. By focusing on one or the other factor, several groups of samples with differently degraded surfaces were created. The fastest way was to place samples in a corrosion chamber where sodium chloride solution was applied at the elevated temperature. The samples were corroded within a few days there. Longer, but in terms of corrosion products layers compactness better way proved procedure where the samples were sealed in the desiccator. At the desiccator bottom the Petri dish with an inorganic acid was placed, in our case, with hydrochloric acid inside. This method corroded the samples within one month. The longest but the most closed to the real live method was the burial of samples into soil or compost. However, this method corroded the samples within two years. Final step after the samples were removed from any corrosive environment, were dried under low pressure and were placed in a barrier film made bag together with moisture and oxygen absorbers. So prepared samples with layers of corrosion products have been treated in a low-pressure low-temperature plasma. Treatment was carried out in the apparatus which is based on the reactor: cylinder of quartz glass having a diameter of 100 mm and a length of 900 mm. The reactor was supplied with a working gas or a mixture of working gases with a total flow rate of 50 sccm. In our case, one is pure hydrogen or a combination with argon. A rotary oil pump was used to provide vacuum. The reactor base pressure was 10 Pa before treatment, while during the treatment it was 150 Pa. High-frequency generator (13.54 MHz) was used for supply the system with energy through two copper electrodes located outside the reactor. According to the energy delivery method, the treatment was carried out in a continuous or pulse mode. The sample temperature was monitored during the experiment and were evaluated the emission spectra from OES. The sample temperature was one of the key factors. The measurement was first done with a thermocouple, later switched to a thermocouple with optical data transmission. A safe temperature was set and then the whole process was controlled through it. In addition, the effect of the energy delivery method, value of the delivered power, sample size, presence of incrusted layers and composition of working gas were studied. After application of plasma, samples were analyzed by SEM – EDX and XRD. After the evaluation of the acquired knowledge and experience, a real artifact - a bronze chisel from the site of Boskovice - was treated. This documentation lacked the artifact, so it could be used to verify the lessons learned about plasma chemical reduction.
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Implementace točivých redukcí v teplárenské praxi / Implementation of micro turbines at thermal power stationsPísařovic, Antonín January 2012 (has links)
The thesis is devoted to the utilisation of expansion turbines in the thermal power stations and in the industry companies using gas pressure reduction for technology purposes. The theoretic part of this thesis deals with the technology equipment such as steam and gas turbines, generators and reduction stations. The special attention is given to the expansion turbines with regard to its dividing in two groups: for steam reduction and for gas reduction. The parctical part includes the preliminary and detailed calculation of the expansion turbin for parameters of reduction line for combustion turbines, the generator proposal and the possibility of power extraction. The economic part completes the thesis with the economic evaluation of investment efficiency.
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Návrh opatření pro plnění emisních limitů u kotle bloku 210 MW / The proposal of measurements to fulfill emission limits for boiler of power unit 210 MWSmokoň, Pavol January 2014 (has links)
This master‘s thesis deals with denitrification of brown coal-fired boiler of electric power plant. First chapters describe technical characteristics of the boiler and possible measurements which would lead to lowering NOx emissions. In order for boiler to meet emission standards valid from 1.1.2016 flue gas treatment by selective catalytic reduction is proposed. Main part of the thesis is thermal calculation of the boiler with modifications necessary in order to apply SCR. The aim of calculation is to determine flue gas exit temperature and temperature at catalyst area in order to assess the suitability of proposed modifications.
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Strojové učení v klasifikaci obrazu / Machine Learning in Image ClassificationKrál, Jiří January 2011 (has links)
This project deals vith analysis and testing of algorithms and statistical models, that could potentionaly improve resuts of FIT BUT in ImageNet Large Scale Visual Recognition Challenge and TRECVID. Multinomial model was tested. Phonotactic Intersession Variation Compensation (PIVCO) model was used for reducing random e ffects in image representation and for dimensionality reduction. PIVCO - dimensionality reduction achieved the best mean average precision while reducing to one-twenyth of original dimension. KPCA model was tested to approximate Kernel SVM. All statistical models were tested on Pascal VOC 2007 dataset.
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In-situ reduktivní dehalogenace / In-situ reductive dehalogenationDvořák, Petr January 2018 (has links)
This master thesis is focused on groundwater remediation of chlorinated ethylenes and methanes in the area of chemical factory Spolchemie in the Czech Republic, Ústí nad Labem city. For these purposes nano zero valent iron particles were used. For the remediation two separate applications of different types of particles together in suspension with tracer (lithium chloride), were carried out. The results from the first application were evaluated by the supervisor of this thesis and are briefly summarized and discussed together with the second application which was evaluated by the author of this thesis. Second application of particles was carried out in October 2015 and observed for 424 days. Observation consisted of monitoring of groundwater level, physical-chemical parameters and collection of water samples for the analysis of concentrations of chlorinated hydrocarbons, their degradation products and several chosen ions. Nanoiron particles had the assumed effect onto the physical-chemical parameters and reduction of contamination. The application of tracer had proven the expected groundwater flow and made a possibility to distinguish between the process of reductive dehalogenation and dilution caused by the injected water, the dilution did not exceeded 5 % in most monitored points. Other...
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Vysoce výkonné prohledávání a dotazování ve vybraných mnohadimenzionálních prostorech v přírodních vědách / High-performance exploration and querying of selected multi-dimensional spaces in life sciencesKratochvíl, Miroslav January 2020 (has links)
This thesis studies, implements and experiments with specific application-oriented approaches for exploring and querying multi-dimensional datasets. The first part of the thesis scrutinizes indexing of the complex space of chemical compounds, and details a design of high-performance retrieval system for small molecules. The resulting system is then utilized within a wider context of federated search in heterogeneous data and metadata related to the chemical datasets. In the second part, the thesis focuses on fast visualization and exploration of many-dimensional data that originate from single- cell cytometry. Self-organizing maps are used to derive fast methods for analysis of the datasets, and used as a base for a novel data visualization algorithm. Finally, a similar approach is utilized for highly interactive exploration of multimedia datasets. The main contributions of the thesis comprise the advancement in optimization and methods for querying the chemical data implemented in the Sachem database cartridge, the federated, SPARQL-based interface to Sachem that provides the heterogeneous search support, dimensionality reduction algorithm EmbedSOM, design and implementation of the specific EmbedSOM-backed analysis tool for flow and mass cytometry, and design and implementation of the multimedia...
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Složitost kompaktních metrizovatelných prostorů / Complexity of compact metrizable spacesDudák, Jan January 2019 (has links)
We study the complexity of the homeomorphism relation on the classes of metrizable compacta and Peano continua using the notion of Borel reducibil- ity. For each of these two classes we consider two different codings. Metrizable compacta can be naturally coded by the space of compact subsets of the Hilbert cube with the Vietoris topology. Alternatively, we can use the space of continuous functions from the Cantor space to the Hilbert cube with the topology of uniform convergence, where two functions are considered as equivalent iff their images are homeomorphic. Similarly, Peano continua can be coded either by the space of Peano subcontinua of the Hilbert cube, or (due to the Hahn-Mazurkiewicz theo- rem) by the space of continuous functions from r0, 1s to the Hilbert cube. We show that for both classes the two codings have the same complexity (the complexity of the universal orbit equivalence relation). Among other results, we also prove that the homeomorphism relation on the space of nonempty compact subsets of any given Polish space is Borel bireducible with the above mentioned equivalence relation on the space of continuous functions from the Cantor space to the Polish space.
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Redukce počtu parametrů v konvolučních neuronových sítích / Reducing Number of Parameters in Convolutional Neural NetworksHübsch, Ondřej January 2021 (has links)
In the current deep learning era, convolutional neural networks are commonly used as a backbone of systems that process images or videos. A lot of existing neural network architectures are however needlessly overparameterized and their performance can be closely matched by an alternative that uses much smaller amount of parameters. Our aim is to design a method that is able to find such alternative(s) for a given convolutional architecture. We propose a general scheme for architecture reduction and evaluate three algorithms that search for the op- timal smaller architecture. We do multiple experiments with ResNet and Wide ResNet architectures as the base using CIFAR-10 dataset. The best method is able to reduce the number of parameters by 75-85% without any loss in accuracy even in these already quite efficient architectures. 1
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Bariatrické výkony a motivace obézních pacientů / Bariatric Surgery and Obese Patients' MotivationLaštovičková, Jitka January 2013 (has links)
This diploma thesis deals with obese patients' motivation to undergo or refuse a bariatric surgery in obesity treatment. The aim of the thesis was to create an overview of patient's motivation to undergo or refuse a bariatric surgery, to show an obese patient's situation (a candidate for a bariatric surgery) from a closer perspective and offer recommendations for the work with obese patients. The qualitative research method in a form of a semistructured interview with the obese patients, who are being treated in obesity ambulances, and with the psychologists, who work with obese patients, was used to analyse the theme of the research. The eight interviews were conducted and analysed with open coding. Obese patients are motivated to undergo a bariatric surgery by improvement of their health, increased attractiveness and by expectation of their obesity's final solution. Obese patients don't want to undergo a bariatric surgery because they're convinced, that they could manage to lose weight and keep it without undergoing a bariatric surgery. Also because they are worried about the bariatric surgery, its complications, its restrictions, required anesthesia and about the failure after undergoing bariatric surgery. Obese patients' motivation to undergo or refuse a bariatric surgery is also influenced by...
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Numerické modely pro posuzování stability zemního svahu / Numerical Patterns for Evaluation of the Stability SlopeEkr, Jan January 2012 (has links)
The master’s thesis deals with numerical patterns for evaluation of the stability slopes. Solutions have been made with finite element method for different design situations with using programme system ANSYS. The results were compared with conventional approaches determining of the slope safety factor.
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