National Repository of Grey Literature 106 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Unconventional methods of increasing power of internal combustion engines
Smrček, Martin ; Pech, Ondřej (referee) ; Štětina, Josef (advisor)
Nowadays the most common method for increasing the performance of internal combustion engines are most used chip tuning or expanding presence of ethanol. The aim of this thesis is to perform a basic analysis of the thermodynamic cycle internal combustion engines, various effects on the thermodynamic efficiency and performance and analyze various methods to additionally increase the performance of the engine. The following are the principles of the analyzed methods, advantages and disadvantages, compared to the methods used in terms of use, price / performance ratio, as well as practical application examples.
UTILIZATION OF FOOD PROCESSING WASTE FOR LACTIC ACID AND ETHANOL PRODUCTION
Hudečková, Helena ; Kráčmar, Stanislav (referee) ; Buňka, František (referee) ; Márová, Ivana (advisor)
The doctoral thesis is focused on the microbial production of lactic acid and ethanol using food processing waste as substrate. Coffee processing waste (spent coffee grounds), wine production waste (grape pomace) and orange processing waste (orange peel) were chosen as substrates for experiments. The theoretical part is dedicated to summarizing current knowledge about waste from food production and possibilities of its processing. It also deals with selected metabolites (lactic acid, ethanol) to which these wastes can be used. Part of the experiments was focused on the characterization and optimization of hydrolysis to maximize the amount of fermentable saccharides. Different combinations of chemical, physical and enzymatic hydrolysis of selected substrates have been tested. Subsequently, a suitable strain for lactic acid and ethanol production was searched for. In the case of lactic acid production, 7 bacterial strains were selected (Lactobacillus casei CCM 4798, Bacillus coagulans CCM 2013, Bacillus coagulans CCM 2658, Lactobacillus rhamnosus CCM 1825T, Lactobacillus delbruckii subsp. bulgaricus CCM 7190, Lactobacillus plantarum CCM 7039T, Streptococcus thermophilus CCM 4757). These strains were first cultivated on the synthetic media containing different kind of saccharides. Afterward, the cultivation on the waste biomass hydrolysates were tested. In the case of ethanol production, 2 yeast strains kmeny (S. cerevisiae CNCTC 6646 a S. cerevisiae CNCTC 6651) were cultivated on hydrolysates of individual waste substrates. Subsequently, the experiments focused on the production of lactic acid and ethanol on hydrolysates of waste biomass in bioreactor were done. The last part of this doctoral thesis deals with the microaerobic pretreatment of lignocellulosic biomass to increase the production of organic acids during the acetogenic phase of anaerobic digestion.
Preparation of Microbial Metabolites from Waste Materials
Zichová, Miroslava ; Márová, Ivana (referee) ; Stloukal, Radek (referee) ; Rosenberg, Michal (advisor)
In this thesis the use of waste materials for the microbial production of important metabolites is reported. The first part is focused on the use of waste paper (a lignocellulosic material) as a non-traditional source for the production of bioethanol. The second part is focused on the immobilization of cellulolytic enzymes, which are used for the hydrolysis of lignocellulosic materials. First, the waste paper (cardboard) was pre-treated using a blender and a vibratory mill. The pre-treated cardboard was used for the production of ethanol by the method of simultaneous saccharification and fermentation. This method was optimized with free cells of Saccharomyces cerevisiae. Then strains suitable for the immobilization were selected. Strains of S. cerevisiae and Pichia kudriavzevii were immobilized by encapsulation into the polyvinyl alcohol carrier and tested again for the ethanol production by simultaneous saccharification and fermentation. In the second part of the work a carrier from waste polyethylene terephthalate bottles was prepared and used for the immobilization of the cellulolytic complex. The basic characteristics were determined, such as optimal pH and optimal temperature, storage, operational and thermal stability, enzyme kinetics and the mode of action of the enzyme. Compared to two other commercial carriers this carrier showed to be suitable for the immobilization of the cellulolytic complex.
Industrial production of ethanol
Flajs, Roman ; Zichová, Miroslava (referee) ; Omelková, Jiřina (advisor)
This bachelor thesis deals with ethanol production for food and car industry. The aim of this work is to give a summary of different kinds of raw material especially lignocelluloses and microorganisms used for its processing and fermentation. The thesis focuses especially on technological process of ethanol production and the utilization of different materials for fuel production.
Calibration of temperature sensors
Záboj, Jakub ; Charvát, Pavel (referee) ; Štětina, Josef (advisor)
How the change of temperature works on physical properties of substance and materials is described in this bachelor’s thesis. Historical development of thermometers and measuring of temperature that goes to the standard temperature scale. There is summary of today's ther-mometers and their detailed descriptions. Select calibrators follow as an instrument for check and calibration temperature sensors (thermome-ters). For example there is described calibration of thermocouple, where we put at their self - characteristics of thermocouple. The most frequen-cies mistakes during calibration are summered there and also description between different calibrations methods finally.
Optimization of ethanol bioproduction from waste materials using SSF method
Filová, Dagmar ; Vránová, Dana (referee) ; Babák, Libor (advisor)
Presented diploma thesis is dealing with the problematics of fuel ethanol production. Relevant basic terminology is explained in the theoretical part, methods of lignocellulose pre-treatments and their conversion to bioethanol are introduced. Attetion is also given to microorganisms used for bioethanol production on industrial scale, as well as analytical instrumental techniques for glucose and ethanol detection. In experimental part, we are focusing on substrate composition analysis – contents of dry matter, cellulose and ash was investigated. Waste paper was chosen as substrate, as it does not find any other use beside recycling these days. Chosen production microorganism, that conversts sugars into etanol was the unknown strain of Saccharomyces cerevisiae. Primal substrate pre-treatment – removal of rigid parts was performed in several physical and physical – chemical ways. Substrate with such pre-treatment was ready for enzymatic hydrolysis, during which monomers from polymer matrix were formed. Ethanol was produced using method of simultaneous saccharification and fermentation, when enzymatic hydrolysis and fermentation take place at the same time and the same container.
Product analysis of electrical discharge in mixtures of water and ethanol
Lokajová, Aneta ; Slavíček,, Pavel (referee) ; Kozáková, Zdenka (advisor)
The thesis is focused on electrical discharge in liquid solutions, in particular in ethanol solutions. In the theoretical section, the plasma is defined along with its important parameters, types of plasma generation and usage of plasma technologies. Main part is focused on the discharges in water solutions. Electric discharges in liquid solutions enable physical processes (shock waves, UV radiaton, electric current) as well as chemical ones (generation of radicals and ions). Both types of the processes are used in many fields – medicine (tool sterilization, destruction of pathogens), consumer technologies (surface adjustemen, processing of the textiles, surface clearing) of environmental protection (clearing water, decomposition of organic compounds). Goal of the thesis was to analyze discharge products on ethanol solution. Multiple samples were measured and concentration od selected products was monitored during the measurement – ethanol, acetone and acetaldehyde. PTR-TOF-MS method was used to collect and analyze the data. This method is well used thanks to quick response and immediate measurement. It produce the reset accurate enough for our purpose. It would be more efficient to use this method in combination with another analytical metohod in the future research, e.g. gas chromatography.
Alternative Fuels in Agricultural Engineering and Trucks
Masnica, Pavel ; Svída, David (referee) ; Dundálek, Radim (advisor)
The purpose of this thesis is introduction of alternative fuels especially in agriculture. Compare the properties of alternative fuels, their impact to ecology and engine power. Advantages and disadvantages of alternative fuels. And their expectations.
Issues of stopping the hydration of alkali-activated slag using organic substances
Chadima, Jan ; Novotný, Radoslav (referee) ; Bílek, Vlastimil (advisor)
This thesis deals with the stopping of hydration of alkali activated slag by organic solvents and investigates to what extent the selected organic solvent affects the results of the analyses. The solvents used were acetone, diethyl ether, ethanol, isopropanol and methanol, and this is because these are the most commonly used organic solvents in practice. Thermogravimetric analysis along with differential thermal analysis was used to assess the degree of influence of organic solvents on the alkali activated slag and Portland cement samples. Methanol and acetone affected the samples the most and the longer the sample was stored in the solvent, the more it reacted with the organic solvent. The adverse interaction of organic solvent was greatest for the Portland cement samples. Samples that were rinsed with diethyl ether prior to analysis had lower mass losses than samples that were not rinsed. In the case of alkali activated slag, it was found that the way in which the thermogravimetric results were affected by organic solvents was highly dependent on the activator used, with the smallest effect observed for Na2CO3 activation, while the largest effect was observed for NaOH activation at temperatures below 600 °C, and for higher temperatures for water glass activation.
Monitoring the stability of the beer brewing process
Tichá, Anna ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the analysis of 3 samples of the same beer, brewed in different batches of the brewing process. The analyzed sample is Dalešická jedenáctka - light lager of 11% of the Stock Brewery Dalešice, a.s., which was taken directly from the lager tanks in the brewery. The aspect we have examined were total protein content, total carbohydrate content, maltose content, total polyphenol content and ethanol content. The Hartree-lowry method was used to analyzed the total protein content. Total carbohydrates were measured spectrophotometrically using anthrone reagent. The maltose content was analysed by HPLC with an ELSD detector. The total polyphenol content was analyzed by the Folin-Ciocaltau reagent method and measured spectrophotometrically. The ethanol content was analyzed on a HPLC using a refractometric detector. The aim of the work was to compare to what extent the process of beer production is stable and what parameters may change in the final product

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