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Characterization of VTR-7000 deposition furnace
Petrová, Lenka ; Ulrych, Jan (referee) ; Semiconductor, Vlastimil Hanáček, ON (advisor)
Tato práce je zaměřena na problém nastavení CVD pece pro produkci ve výrobním závodu. Problém je, že přesná zařízení jako depoziční pece musíbýt pro produkci nastaveny až na místě, kde budou provozovány. Toho je možno docílit pomocí statistických nástrojů jako například DOE (design of experiment). Vstupní hodnoty procesu ovlivňují výstupy. Úkolem DOE je definovat, jakým způsobem. Z předchozího DOE provedeného v závodě COM1 vyplývají některá nastavení proměnných. Jiné proměnné musí být nastaveny dle předchozích zkušeností. Úkolem práce je seznámit čtenáře se základy depozice z plynné fáze a konceptem DOE. Následně je navržen vlastní experiment. Tento je vyhodnocen a výstupem práce je pak ideální nastavení reaktoru. Čtenáři bude též nepřímo představen proces DMAIC, který byl použit při samotném experimentu a vyhodnocování v ON Semiconductor, Rožnov pod Radhoštěm, CZ4 WFAB.
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FET aging model
Novosád, Jiří ; Legát, Pavel (referee) ; Semiconductor, Aleš Litschmann, ON (advisor)
This work deals with problems aging of unipolar transistors. In theoretical parts are described the mechanisms which causing aging unipolar transistors and way leading to the restriction the change of parameters in time. The measurement and data evaluation was built on theoretical knowledge. The model of aging FET is a result of this works; it is creating extraction of data from measured data. Finally, the degradation constants are evaluation from this data. This FET aging model is easy to use in simulators of electronics circuits including aging simulations (e.g. ELDO).
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Inner geometry optimization of flat-panel photobioreactor
Hlaváč, Ivan ; Babička Fialová, Dominika (referee) ; Rebej, Miroslav (advisor)
This master thesis focus on optimatization of flat-panel photobioreactor. The optimatization was performed using CFD models and Design of experiement. The CFD model used for the optimatizaion was before performing the experiment validated with real experiment data. Hydrodynamic parameters affecting microalgae yield were monitored during CFD calculations. They were: gas holdup, gas velocity, turbulent kinetic energy, dead zone ratio. interfacial area and shear stress.The photobioreactor with a stirrer and with vertical baffles, which were selected based on research, were compared. The higher values of hydrodynamic parameters were reached with a stirrer. Baffels were evaluated as more suitable for microalgae, which are more sensitive to shear stress.
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Aplication of picosecond laser micromachinning for manufacturing of reflective DOE for CW power lasers
Mrňa, Libor ; Novotný, Jan ; Kolařík, Vladimír
Reflective optical elements are advantageous in terms of ease of cooling, where even a less efficient element can be easily operated without damage by a simple cooling system. When material interacts with the ultrashort pulses, the interaction is largely non-thermal and the material can be removed in a very defined manner without affecting the surrounding area. Direct ablation with ultrashort laser pulses enables fast and flexible fabrication of diffractive optical elements (DOEs). Ultrashort pulses can also be used to machine difficult-to-machine materials with conventional lasers and easily create spatial structures on the order of tens of micrometers.
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Machining of bio-composite materials
Obid, Daniel ; Slaný, Martin (referee) ; Zouhar, Jan (advisor)
This diploma thesis is focused on machining of composite materials mainly from natural fibers. The first part describes the production of composite materials and the methods used for their machining. The practical part of the work is devoted to the study of the influence of tool choice and cutting conditions on the cutting process and the quality of machined surfaces. The measured data are analysed using regression analysis.
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Obtaining and complex charaterization of Aronia spp. extracts
Seidlová, Kateřina ; Zemanová, Jana (referee) ; Veselá, Mária (advisor)
Aronia (Aronia melanocarpa) is a berry fruit with distinctive sensory characteristics and health-promoting properties. Polyphenols are the main bioactive compounds found in aronia including natural pigments – anthocyanins. Bioactive compounds are usually obtained from natural materials by extraction, in this work, two methods of extraction were compared – maceration and PHWE. Based on the total phenolic content, maceration was chosen as a more suitable method and then was optimized with statistical model – Design of Experiment. Optimal conditions were set to temperature of 30 °C, extraction agent 50 % ethanol, solid-solvent ratio 10 g per 50 ml and time of extraction for 30 minutes. Extract obtained under these conditions was characterised by total phenolic content – 1441 ± 90 mg/100 g DW, total anthocyanin content 943 ± 8 mg/100 g DW and antioxidation activity by ABTS 24,78 ± 0,09 molTE/g. In total of 25 volatile compounds were indentified in the optimal extract with content > 0,5 %. Major part created aldehydes and esters, with the main compounds being benzaldehyde (32,25 %) and methyl hexanoate (21,37 %).
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Weight control of soft cheese formed on a manual production line
Páral, Marek ; Zemanová, Jana (referee) ; Tomečková, Šárka (advisor)
The thesis deals with the control of the weight of soft cheeses during molding on a manual line. The theoretical part describes the classification of cheeses into groups, the basic characteristics of soft cheeses and their representatives. Furthemore, the whole technology of soft cheese production is processed and the effects on curd formation and factors influencing the weight of cheeses during molding are explained. The theoretical part ends with the basics of statistics for data processing. Basic measuring techniques (dry matter measurement, pH measurement, measurement of temperature and weight) were selected to determine the technological parameters (pH of whey, pH, dry matter and temperature of cheese grain, weight of cheese etc.) to describe the quality of grain in the experimental part of the thesis. The Design of Experiments method was used to find the optimal setting of the molding machine. Three partial experiments were designed and done. Results were verified in real production. The pH of whey was chosen to describe the grain quality. Two factors have been discovered that have a significant effect on the weigh of cheeses during molding, namely the position of the operator during molding and the amount of whey flowing into the forms with the cheese grain. The proposed molding modifications were successfully tested in production and no statistical difference was found between the weight of cheeses formed with the new setting of molding machine.
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Obtaining and complex charaterization of Plectranthus spp. extracts
Boboková, Alexandra ; Saláková, Alena (referee) ; Vítová, Eva (advisor)
Plectranthus amboinicus is a herb that was found to have a lot of bioactive compounds, most of them are polyfenolic compounds. Extraction is neccesary to obtain bioactive compounds and to use them subsequently in food or cosmetic industry. Three methods of extraxtion – maceraction, PHWE and PFE, were used in this study. The best yield of extracted polyfenols was observed by maceration. Maceration was, in the next step, optimized using mathematical statistical method of planned experiment (DOE). The optimal conditions found for extraction were: temperature 60 °C, solvent 40% ethanol, time 90 minutes, solid-solvent ratio 1:10. Total phenolic compunds content in this extract was 0,18 ± 0,05 mgGAE·ml-1, which means 1,83 ± 0,53 mgGAE·g-1 of plant. The antioxidant activity was 148,69 ± 26,92 gTEACml-1. Percentage of radical scavenging activity ABTS•+ was 30,03 ± 5,44 %. Further, 27 of volatile aroma compounds were identified in optimal extract, the most important were: -selinene (16,67 %), trans--bergamotene (14,22 %), caryophyllene (14,11 %), 3-carene (8,22 %), -copaene (7,55 %), -terpinene (6,28 %), humulene (5,87 %), cadina-1(10)-4-diene (5,19 %).
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Foaming of fermentation residues during a vacuum evaporation
Knob, Jan ; Brummer, Vladimír (referee) ; Vondra, Marek (advisor)
The diploma thesis deals with the processing of digestate, which is the remaining material after biogas production. It aims to experimentally prove how chosen operational parameters of antifoaming agents influence digestate foaming associated with the vacuum evaporating technology. Based on the research of available antifoamers and the issue of digestate foaming itself, it was observed how three selected antifoamers (i.e. rapeseed oil, silicone antifoamer Erbslöh Schaum-ex and oleic acid), together with the decrease in the pH factor of the evaporating digestate, influence the final foam production. For the purposes of the research, an apparatus simulating the vacuum evaporating process was set up in which the heated sample was brought to boil by gradual pressure decrease. The process of foaming was observed in a transparent cylinder of a testing culumn. The essential part of the experimental activity is represented by a planned experiment which by means of a DoE (Design of experiments) method proved rapeseed oil to be very efficient. In contrast, other antifoamers, as well as the influence of the pH factor decrease, manifested themselves as insignificant factors, while the oleic acid even supported the foaming. The supplementary measurements led to a more detailed research of the effects of rapeseed oil and to the construction of a mathematical model describing how the concentration of rapeseed oil undermines the amount of generated foam. The main contribution of the thesis is firstly the evidence that rapeseed oil plays an important part in the reduction process of digestate foaming and secondly the determination of minimum substance concentration leading to the foaming reduction of a particular sample which is considered efficient enough to enable functioning of a vacuum evaporator. The thesis has also experimentally demonstrated the influence of some polymer organic flocculants which have been proved to support the foaming.
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Elimination of internal stress in the polycarbonate moldings
Selucký, Jaroslav ; Hrbáček, Jan (referee) ; Chladil, Josef (advisor)
This diploma theses raises the issue of internal tension in two-component outer lense, which are made by injection of polycarbonate. The theses gives a more detail view on treatment of the lenses in heating ovens. Heating ovens have been used for decreasing the internal tension in lenses. The subject of the experiment is to determine the influences of the adjustable parameters of the heating oven. The Experiment will be taken by DoE method. The influence of the adjustable parameters is researched and compared among the two types of outer lense with different type of design.
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