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Preparation and characterisation of ceramic electroactive materials for Na-ion batteries
Vaněk, Martin ; Libich, Jiří (referee) ; Čech, Ondřej (advisor)
Hlavním cílem této práce je charakterizace vzorků titanátů, jako materiálů pro sodíko-iontové (Na-ion) akumulátory. Syntéza některých vzorků je součástí této práce. Charakterizace je zaměřena na elektrochemické vlastnosti, složení a morfologii použitých materiálů. První část se zabývá lithium-iontovými (Li-ion) akumulátory. Byly vybrány, protože jsou ve vědeckých článcích dobře popsány a základní funkční princip je aplikovatelný také na Na-ion akumulátory. Materiály používáné pro katody, anody a elektrolyty následují po krátké části shrnující parametry a konstrukci Li-ion akumulátorů. Následující kapitola je zaměřena na sodíko-iontové akumulátory. Srovnání sodíku a lithia je následováno materiály používanými pro elektrody a elektrolyty (s důrazem na anodové materiály). Třetí část popisuje analytické metody použité pro charakterizaci elektrod a materiálů. Jedná se o elektrochemickou charakterizaci (cyklická voltametrie a galvanostatické cyklování s potenciálovým omezením), morfologii (rastrovací elektronová mikroskopie) a složení (X-ray difrakční spektroskopie). Poslední dvě kapitoly obsahují syntézu a charakterizaci sodného titanátu a charakterizaci dvou vzorků TiO2. Výsledky této práce jsou shrnuty v závěru.
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Use of selected fluorescence techniques to characterization of microbial cells
Vaněk, Martin ; Pekař, Miloslav (referee) ; Márová, Ivana (advisor)
Carotenoids are one of the most abundant natural pigment. Furthermore, they have great potential for wide industrial utilization. Nowadays, prefered (and cheaper) synthetic method counters progressively improved biotechnological production. Far more cheaper production should be reached via implementing methods of on-line optimization, such as flow cytometry. In this thesis the dependence of yeasts autotofluorescence intensity on carotenoids concentration in dry mass was studied. The dependence was established by means of linear regression. Moreover, the dependence between light scatter and the amount of dry mass was established by means of model utilizing forward scatter, side scatter and number of cells in unit volume. Yeasts' cells was also studied under the lenses of laser scanning confocal microscope. The goal was to localize carotenoids inside cells. Experiments undertaken suggest that they are localized inside the lipidic granules, but more experiments are required for a proof.
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Additive in unsaturated polyester resin for pultrusion process
Vaněk, Martin ; Bábík, Adam (referee) ; Přikryl, Radek (advisor)
Theoretical part of bachelor’s thesis deals with composite materials based on fiberglass and unsaturated polyester resins. It focuses on Low profile aditives, which are added in matrix to lower polymerization shrinkage. The thesis studies the influence of additives on the changes of matrix behavior and mechanical composite properties. Nature of those changes was monitored by differential scanning calorimetry (DSC), scanning electronmicroscopy (SEM), touchscreen profilometry, tensile test and bending test. Influence of LPs on matrix polymerization shrinkage, roughness and geometry in fiberglass composites were evaluated. Matrix Polipol 3870 and aditive Norsolook A71074 were found to be the most suitable because the best result was observed.
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Photopolymerization kinetics of dimethacrylate dental resin
Vaněk, Martin ; Bystřický, Zdeněk (referee) ; Poláček, Petr (advisor)
Aim of magister´s thesis was to study reaction kinetics of dental materials. Thesis was focused on dimethacrylate dental polymers, which are for example used for dental restoration, tooth repair and creating now teeth. First part of the thesis concentrates on influence of molar ratio on reation kinetics by addition of other monomer to polymer resin. Second part concentrates on influence of addition of additive silica on reaction kinetics of polymerization. Essential variables know as a polymerization ratio, conversion, gel point, glass transition temperature and storage modulus were studied. Firstly, polymerization ratio and conversion were observed by differential scanning calorimetry (DSC). Secondly rheology was observed by photoreometr. Finally, glass transition temperature and storage modulus were observed by dynamic mechanical analysis (DMA). Behaviour changes caused by addion of monomer or filler point out decrease of polymeration ratio and converstion. Same behaviour was observed by short exposure. In order to established network formation, values of gel point increased by higher concentration of monomer or filler. Glass transition temperature and storage modulus measured by DMA were evaluated. Those valuables had variable tendency due to monomer acting like filler at higher concentration. Also contradictory impact of different material conversion and filler concetration was discussed.
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Study of carotenogenic yeasts doring growth by using advanced instrumental techniques
Vaněk, Martin ; Breierová, Emília (referee) ; Márová, Ivana (advisor)
This work is dealing with application of advanced fluorescence techniques for gaining knowledge about culture development during fermentation of red yeasts. Flow cytometry was used for auto-fluorescence measurement a carotenoids quantitation. It was resolved that while carotenoids are stored mainly in membranes the technique was feasible. If red yeast starts to accumulate carotenoids into lipid bodies mainly throughout the course of stationary phase, then the method starts to fail. Flow cytometric method using cell size measurement and light scatter for lipid quantitation was proved as applicable, too. However, it works only if cells are not starved. Individual calibration for each species is needed for elimination inter-species variations of intracellular structures. Fluorescence lifetime imaging microscopy was also used for studying of red yeast. Inherent ability to resolve different fluorescent species of the same molecule, which arise due to different molecular environment, helps with quantitation of cellular lipidic structures changes through the course of fermentation. Increase in the levels of carotenoids and/or rigidity of membranes was found as mechanism of protection during metabolic shifts, when intracellular content is vulnerable to damage.
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System level analysis of thermal properties of integrated circuits
Vaněk, Martin ; Jirák, Josef (referee) ; Frk, Martin (advisor)
Hlavním cílem této práce je shrnout základní poznatky o tématech spojených s teplem, se zaměřením na aplikace v elektrotechnice, a provést měření tepelného odporu pouzder integrovaných obvodů. První část je praktická a zabývá se teorií přenosu tepla, tepelnými vlastnostmi materiálů a metodologií JEDEC pro měření tepelných vlastností pouzder integrovaných obvodů. Druhá část se skládá ze sestrojení teplotní komory s přirozeným prouděním, návrhu testovacích desek plošných spojů a tepelných měření. Na závěr je shrnuta metodologie pro měření tepelného odporu čip-okolí spolu s uvedením praktických poznatků z předchozích měření. Tato práce může sloužit jako základ pro další vyhodnocování tepelných vlastností integrovaných obvodů a pro ověřování přesnosti tepelných simulací. Také může pomoci při vyhodnocování tepelné vodivosti desek plošných spojů.
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Optimization of the performance of fuel cell stacks using an ultrasonic humidifier.
Vaněk, Martin ; Yakovlev, Yurii (advisor) ; Václavů, Michal (referee)
Title: Optimization of the Performance of Fuel Cell Stacks Using an Ultrasonic Humidi- fier. Author: Martin Vaněk Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This work is concerned with the optimization of the performance of PEM hydrogen fuel cell stacks, a technology that opens up new possibilities for clean energy storage and restoration. We have hand-built a PEMFC open-cathode stack of 20 cells and measured its basic characteristics such as the j-V and j-P curves as well as the dependency of the temperature of the stack on power produced by the stack for constant power of the cooling fans. We have implemented and tested the performance of a new method for water and thermal management - the humidification of air via the use of an ultrasonic water fog generator. Several tests - measuring cooling efficiency, voltage variations between different cells, and j-V and j-P curves - were performed under different temperatures and with or without humidification. Keywords: fuel cell, self humidification, open cathode, performance 1
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Set-off Defence
Vaněk, Martin ; Dvořák, Bohumil (advisor) ; Holčapek, Tomáš (referee)
63 Set-off Defence Abstract The thesis deals with set-off from the point of view of procedural law and using the method of functional interpretation of law, strives to provide answers to questions that appear in the court proceedings in connection with its use. It builds on theorists who dealt with the issue of inducing an effect of set-off in the proceedings in the late 20th century, but also takes into account the findings of current academic community and presents the judicial conclusions reached by (not only Czech) courts. The thesis is divided into 4 chapters. The first chapter briefly deals with the substantive legislation of set-off (especially the requirements laid down for the receivables that are to be set-off, and cases where set-off is prohibited by law). A declaration of set-off as a substantive act may be decisive in assessing the admissibility of set-off in proceedings. The second chapter describes the origin of set-off in ancient Rome and the different concepts of set-off in current legal codifications, which is the result of inconsistent interpretation and reception of this institute by medieval scholars. This is reflected by Czech legal science in existence of civilian and procedural theory of offsetting. In the third chapter, the thesis deals with purely procedural aspects of set-off. The...
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Stroje a strojní linky pro zpracovní dřevního odpadu - štěpkovače
Vaněk, Martin
Thesis describes machines and mechanical lines for the processing of wood waste - chippers. The teoretical part reports about chippers and their ulitization. Thesis introduces basic division of chippers with presentation of basic types of crushing devices. Czech and foreign producers are presented with their produced types of machines. At the end of the teoretical part are described individually machines and machinal lines with complete work process. This process is used for felling and following disposal of wood mass in wood lands and in cities. In the practical part thesis compares desinged machine sets in field laboratory mensuration. Measured values were compared. Costs and economical aspects of the compared machine lines are quantified in the end.
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Vývoj komoditní vertikály cukrové řepy v českém agrárním sektoru
Vaněk, Martin
The diploma thesis deals with the definition and characteristics of decisive factors that influenced the production and economic context of the development of the individual phases of the commodity vertical sugar - sugar beet in the Czech Republic and within the EU common market. It defines in more detail the crucial changes affecting the business environment related to sugar beet and sugar production. It characterizes the impacts of specific measures on individual phases of commodity vertical. It examines the development of sowing areas, yield per hectare and sugar content of sugar beet for agricultural producers. Within the downstream industry, it describes the development of our sugar industry and compares current processing capacities with selected EU countries. In conclusion, the thesis deals with the balance of import and export of sugar and confectionery, as well as the analysis of the relationship between price and sugar consumption and the reaction to price movements in individual phases of commodity vertical.
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