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Effect of heat treatments on the microstructure and hardness of high-entropy alloy
Jesenská, Mária Ľudmila ; Adam, Ondřej (referee) ; Moravčíková de Almeida Gouvea, Larissa (advisor)
V tejto práci je študovaná neekviatomická Al0.2Co1.5CrFeNi1.5Ti vysoko entropická zliatina, ktorá bola vyrobená pomocou vákuového indukčného tavenia. Zliatina v odliatom stave bola analyzovaná a tepelne spracovaná pri teplote 1000 °C po dobu 5h, a následne podrobená tepelnému spracovaniu pri teplote 750 °C po dobu ďalších 5h, s cieľom skúmania vplyvu teploty a doby tepelného spracovania na fázové zloženie, mikroštruktúru a mechanické vlastnosti. Na vyhodnotenie možných fáz prítomných v zliatine bol použitý pseudobinárny fázový diagram (CALPHAD). Mikroštruktúra zliatin bola charakterizovaná a chemicky analyzovaná pomocou röntgenovej difrakcie (XRD), elektrónovej mikroskopie (SEM) a energeticky disperznej spektroskopie. Výsledné vyhodnotenie tvrdosti materiálu prebehlo pomocou skúšok mikrotvrdosti a nanoindentácie.
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Influence of fluxes on weld metal properties
Holub, Kamil ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
This thesis deals with the topic of submerged arc welding – an electric arc method of fusion welding, that uses a layer of granulated flux to shield the weld pool from atmospheric gases. Theoretical part is devoted to the description of the welding method and fluxes currently used. The practical part contains an experiment, which consists of making two weld deposits on structural steel S235JR by using different fluxes. First weld deposit is made with OK 10.62 Flux. The same flux alloyed with the Tribaloy T-800 laser cladding powder is used for the second weld deposit. Test specimens are examined on the basis of influence of fluxes combined with a single electrode wire.
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Chemical composition of berries juices from some cultivars of European elder
Šafránková, Petra ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This thesis deals with chemical composition of the juice from selected species of elderberry (Sambucus nigra L.). The theoretical part is dedicated to botanical characteristic of elderberry including the origin and the extension. There are also mentioned the medical effects of elderberry with the description of the cultivation of this herb with the examples of particular cultivated species. In the experimental section were laid down the particular chemical parameters (yield, pH, relative density, titrable acidity, formol number, content of instant dry mass and reducing sugar) in the juice from the fruits of these cultivated species of elderberry: Albida, Allesö, Aurea, Bohatka, Dana, Heidegg 13, Haschberg, Körsör, Mammut, Pregarten, Riese aus Voßloch, Sambo, Sambu, Samdal, Sampo, Samyl a Weihenstephan. The median of the yield has been 700,0 ml/kg, the median for the pH assessment has been 4,03. The median of relative density of all species was 1,0361, the median of titrable acidity was 141,83 mmol l -1. The median of the overall content of amino acids was 30,5 ml 0,1 mol l-1 NaOH/100ml, the median of the content of the dry mass was 9,5 weight %. The median of the assessment of the reducing sugar was 5,02%.
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The basic chemical parameters of berries from some black currant cultivars
Sailová, Genar ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This thesis deals with the chemical analysis of the juice from fruits of cultivated varieties of blackcurrant (Ribes nigrum L.) The theoretical part is dedicated to botanical characteristic of black currant including the origin and the extension. There are also mentioned the history of cultivation currant and breeding of the varieties of black currant. Chemical composition of currant is also described in this part. In the experimental part some basic chemical parameters (yield of juice, soluble dry matter content, dry matter general content, pH, titratable acidity, formol number and reducing saccharides content) of four black currant cultivars were determined.
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Study of the effect of metallurgical and technological parameters on mechanical properties of aluminium alloys
Pešek, Jakub ; Krahula, Karel (referee) ; Zemčík, Ladislav (advisor)
Sugested thesis has been made with the intent to observe and describe the length of the modifying effect of three different types of modifiers and their effect on the mechanical properties of aluminium alloy. Next step was to process and evaluate links between mechanical properties and chemical composition. Chemical analysis and mechanical properties of cast samples were obtained. For this purpose and a method of metallographic processing was applied afterwards. The grain size was evaluated before and after the heat treatment. Measurements of the secondary dendrite branches and evaluation of the eutectic morphology were made. The hardness was measured on selected samples.
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Characteristic of nutrition values of meat from different animals
Kubištová, Petra ; Zlámalová Gargošová, Helena (referee) ; Omelková, Jiřina (advisor)
ABSTRACT In this thesis, there were assessed basic nutrition values of meat from different animals. Beef meat (bulls, heifers and veal), pork meat ( castrates, boars and gilts ), rabbit meat and chicken meat were included in the experimental part. There were moisture, lipids, proteins, ash and hydroxyproline determinated. Attention was given especially to the content of lipids and moisture. The animals were compared in terms of their type and on the basis of possible differences between sex (beef and pork meat), breed (beef and rabbit meat) or between different parts of animals` body (chicken and rabbit meat). Individual types were also compared with each other. For human nutrition it is possible to recommend veal meat, which contained the least amount of fat, MLD from rabbit meat and chicken breasts. Pork meat from young animals is comparable to chicken breast as regards the content of fat. We should also not omit beef meat in our bill of fare. Thanks to breeder technology the beef is now lower in fat than it used to be and contains valuable matters of red meat.
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Production of castings from austenitic-ferritic hyperduplex stainless steels
Kaněra, Miloš ; Pernica, Vítězslav (referee) ; Záděra, Antonín (advisor)
The thesis deals with hyper duplex stainless austenitic-ferritic steels and their mechanical and castability properties. The evaluation of resistance to pitting corrosion is divided by PRE values. Steels with a PRE value higher than 48 belong to the group of hyper duplex steels. The theoretical part contains an introduction to the chemical composition, structure and properties of these steels. The practical part is focused on the conditions of tendency to crack castings during solidification and cooling. Furthermore, there is evaluated influence of intermetallic phases on mechanical properties.
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Quality parameters of dry fermented sausages
Pavlík, Zdeněk ; Ing.Miroslav Jůzl, Ph.D. (referee) ; Alena,, Saláková (advisor)
The aim of this study was to evaluate quality parameters of dry fermented sausages. Samples of two types of dry fermented sausages were sampled – sausage “Poličan“ and “Lovecký salám“, from three different producers. Basic physical-chemical analysis of quality parameters were performed in sausage mixture and immediately after end of ripening (21 days for Poličan and 16 days for Lovecký salám). Results of quality parameters analysis were compared with requirements of Czech legislation and differences between producers were observed. There were significant differences between producers, however all of them met requirements set by 326/2001 Czech notification as amended of Ministry of agricultural.
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