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Step-Up converter for mobile device
Gabriel, Petr ; Červinka, Dalibor (referee) ; Huták, Petr (advisor)
The purpose of this bachelor‘s thesis is about to intoduce possibilities of construction and use of switched power supplies. Thesis focuses mainly to description of different types of converters. There are possibilities of power supplie's design and sizing of its components described in this thesis. This thesis contains concrete design of power supply for realization. There are results of the measurement and comparision to the parameters given by manufacturer set forth at the end of this thesis.
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Switching supply source 5,5kV/4,3kW with silicon-carbide semiconductors
Gabriel, Petr ; Patočka, Miroslav (referee) ; Vorel, Pavel (advisor)
This thesis is about to introduce the development of switched power supply with output voltage of 5,5 kV and power of 4,3 kW. This thesis directly follows the outputs of two previous semester projects. Main task is about to finish the development of remaining printed circuit boards and perform launching of all parts of developed power supply. Next necessary task is about to assemble a functional prototype of the supply using the developed parts, performing a series of measurement supply’s parameters and creating of technical documentation of mechanical part. There are all stages of supply’s development included in this thesis. From the first part, that describes various types of converters, through the design of all the supply’s parts, to final implementation of functional prototype. There are the results of measurement supply’s parameters at the end of this thesis.
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Objects Classification in Images
Gabriel, Petr ; Petyovský, Petr (referee) ; Janáková, Ilona (advisor)
This master's thesis deal with problems of classification objects on the basis of atributes get from images. This thesis pertain to a branch of computer vision. Describe possible instruments of classification (e.g. neural networks, decision tree, etc.). Essential part is description objects by means of atributes. They are imputs to classifier. Practical part of this thesis deal with classification of object collection, which can be usually found at home (e.g. scissors, compact disc, sticky, etc.). Analyzed image is preprocessed , segmented by thresholding in HSV color map. Then defects caused by a segmentation are reconstructed by morfological operations. After are determined atribute values, which are imputs to classifier. Classifier has form of decision tree.
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Enzymatic hydrolysis of waste cardboard using the SSF method - a source of raw materials for the production of liquid biofuels.
Hlaváček, Viliam ; Stloukal, Radek (referee) ; Gabriel, Petr (advisor)
This master’s thesis discusses the useof enzymatic hydrolysis process of waste cardboard using simultaneous saccharification and fermentation (SSF) as a source of raw materials for production of liquid biofuels. This thesis is based on theses written by Ing. Brummer and Ing.Lepař.Thus, results gained in these works have been used and also further developed. The theoretical part summarizes the reasons for further development of SSF method and discusses, as well, the achievements reached in the processing of lignocellulosic waste materials by the SSF method so far.This section also discusses the general characteristics of lignocellulosic materials and also of the cellulolytic enzymes. It focusses also on individual pretreatment methods of lignocellulosic material and options of increasing the yield of the whole process. The experimental part verifies the particular results reached in previous theses and at the same time a further optimization of the method has been carried out because of the transfer of the whole process into a fermenter. Cardboard was set as the substrate for the experiments as it was evaluated by Ing. Brummer as the best one for enzymatic hydrolysis which was carried out by enzymes from Novozymes®. Parameters such as temperature, pH and kind of used buffer, the loading concentration of substrate and enzymes, were set according to the thesis of Ing. Lepař, which was aimed to their optimization. The SSF process done in fermenter of 2.0 l volume confirmed the previous results and furthermore it has been more effective through optimization of the added inoculum volume. It has been confirmed that the best substrate is cardboard finely grinded by vibrating mill. Also experiments with added nutrients had been done as an effort to increase the ethanol concentration, but these haven’t resulted insatisfying results. The maximal concentration of ethanol was 23,49 g/l, which was achieved after further optimization of various conditions. This result equals to experimental yield of 84,79 %.
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The enzymatic hydrolysis of waste paper - a source of raw materials for production of liquid biofuels
Lepař, Petr ; Stloukal, Radek (referee) ; Gabriel, Petr (advisor)
In diploma thesis the process of enzymatic hydrolysis of waste paper as a source for the production of liquid biofuels is discused. It follows directly the homonymous diploma thesis from Ing. Brummer, and it is based on the findings, which were solved and decided in previous work. In the theoretical part there is a summarization of basic information on the enzymatic hydrolysis of waste paper and the associated influences of various factors of the rate and degree of hydrolysis. Higher attention is paid to a waste cardboard and its pretreatment methods due to the maximalization of the yield of hydrolysis. The next part summarizes options of the fermentative production of biofuels, focusing on the method of simultaneous saccharification and fermentation, where the further appropriate organism for ethanol fermentation is discussed. The last part is about the technological process from the raw material input to the separation of ethanol. In the experimental section the pre-treatment of waste paper in order to maximize the efficiency of hydrolysis was examined. The best results were achieved using a vibratory mill. In addition, various parameters for simultaneous saccharification and fermentation were optimized using enzymes from Novozymes® company and the yeast Saccharomyces cerevisiae. The conversion rate of waste paper cellulose to reducing sugars was observed by spectrophotometric method by Somogyi - Nelson and the amount of produced ethanol was quantified using HPLC / RI. As a part of this thesis some conditions (amount of enzyme, substrate, nutrients, yeasts, temperature, pH, type of buffer) were optimized to maximize the effectiveness of the overall process. All experiments were carried out on corrugated cardboard, which was chosen as the most promising material for hydrolysis that was among the waste paper pulp in diploma thesis by Ing. Brummer.
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Enzymatic hydrolysis of waste paper pulp - source of raw material for production of liquid biofuels
Brummer, Vladimír ; Ing.Marián Illáš (referee) ; Gabriel, Petr (advisor)
This master’s thesis is aimed at process of enzymatic hydrolysis of lignocellulosic material – waste paper as a source of raw material for production of liquid biofuels. In the theoretical part of this work are summarized previously used methods of hydrolysis and lignocellulosic materials used for the process of hydrolysis as a source of fermentable sugars for fermentation technology. The different types of waste paper are evaluated from the composition and usability with consideration to the papermaking process in order to select the appropriate type of waste paper for the enzymatic hydrolysis process. In the next part of this work are suggested technological premises and procedures for the preparation of raw materials and the subsequent enzymatic hydrolysis of these pre–treated materials. In the experimental part were optimized parameters of enzymatic hydrolysis using the Novozymes company enzyme package. Enzymatic degradation of cellulose to reducing sugars was observed using Somogyi – Nelson method. For the verification of hydrolysis conditions were used model materials with high cellulose content – pulp and filter paper. Conditions, which seems to be the best after testing on the model materials, were verified on specific waste paper materials – offset cardboard, recycled paper, matte MYsol paper and for comparison again on model materials – pulp and filter paper. The highest yields was achieved with the use of cardboard, which was further tested using various combinations of pretreatment to material for purpose of increase the yields of hydrolysis.
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Possibilities of fermentation production of butanol as raw material for motor fuels - introductory study
Janošková, Lenka ; Radek, Stloukal (referee) ; Gabriel, Petr (advisor)
The aim of this work was to map out the theoretical basics of acetone-butanol fermentation. In addition, it is to find available data for possibility of the industrial use of this process and to make conclusion for next procedure. The microorganisms producing butanol, conditions of fermentation and usable raw material were described. Batch, Fed-batch and Continuous fermentation processes are described in more detail from the point of view of productivity of process and yield. Available data was evaluated, but there was a lack of technological data to construct an operational system. Therefore, an experimental pilot plant system was constructed that allowed different types of microorganisms and substrates to be tested. The pilot plant system is for single stage Continuous fermentation with gas stripping product recovery with possibility of expansion to two-stage Continuous fermentation. As well the balance of this process was done.
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Optical Absorption Sensors for Evaluation of Yeast Acidification Power
Rychtáriková, Renata ; Frančič, N. ; Hetflejš, Jiří ; Kuncová, Gabriela ; Gabriel, P. ; Lobnik, A.
The acidification power test provides a fast and simple method of assessing the ability of cells to perform a successful fermentation. It has been used as a rejection criterion for assessing the technological quality of starter yeast cultures in brewing, cider production, baking, as well as cheese making based on lactic acid bacteria. The cell acidification power responses to pH decrease of the environment after glucose addition. We have prepared novel recognition elements of pH sensors suitable for evaluation of yeast acidification power by absorption of two pH sensitive sulfonphthalein dyes (bromocresol green and bromophenol blue) into hydrogel of poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate). The absorption spectra, function ranges, pKa values, and response times for each absorbed dye were evaluated, compared with the free dyes, and further discussed with regard to its application to the acidification power test.
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