National Repository of Grey Literature 95 records found  beginprevious41 - 50nextend  jump to record: Search took 0.01 seconds. 
New generation of biofuels
Pražák, Vojtěch ; Lisá, Hana (referee) ; Baláš, Marek (advisor)
This bachelor's thesis deals with different generations of biofuels. Their advantages and disadvantages and problems associated with their use in practice. The first part of the theses focuses on legislation and acquaintance with the issue of biofuels as a whole. The second part is focused on acquaintance and description of individual biofuels with examples of use in practice. At the end of the work there is an analysis of individual generations, representation in the fuel market and their efficiency.
Usage of flue gas as a source of CO2 for algae cultivation in bioreactors
Slonek, Jaroslav ; Juřena, Tomáš (referee) ; Brummer, Vladimír (advisor)
This master`s thesis is focused on possibility of use of flue gas as source of CO2 for algae cultivation in bioreactors. The first part of the master`s thesis is devoted to a qualitative and quantitative description of flue gas sources as CO2 source for algae cultivation. In the thesis industry sectors with the largest share of CO2 emissions on a global scale and in the Czech republic are summarized. On the basis of these data it was possible to determine cheap sources of CO2 for algae cultivation producing valuable biomass and other bio-products. The composition of flue gas from these sources was discussed in this section also with given expected outlook within the following years. The next part of the thesis is devoted to the influence of flue gas properties on algae cultivation. The impact of flue gas individual parameters on cell growth rate, quality and composition of biomass is described there. The description and design of the bioreactor is processed in the next part of the thesis. The experimental part of the thesis was performed on a bioreactor with similar properties. The next part of the thesis describes the effect of light on algae cultivation and the design of a regulation scheme for bioreactor light source. The experimental part of the thesis describes methods used to determine the concentrations of flue gas substances that could pass from flue gas into cultivation medium for algae cultivation to measure the changing composition of the flue gas in the closed experimental bioreactor system. The processed data from experimental measurements are presented and are discussed. The change in the composition of the culture medium for algae (without the presence of algae) due to flue gas aeration was monitored in the experimental part. It includes also the measurement of the change in the composition of the flue gas in time. All obtained and collected information are then summarized and discussed in the final part of the master`s thesis.
CO2 reduction with algae
Naider, Jakub ; Rebej, Miroslav (referee) ; Vondál, Jiří (advisor)
The aim of this final thesis is the process of algae cultivation their use for carbon dioxid reduction. The main objective of this work is the mass and heat balance of the photobioreactor and the design of a temperature control system. Within the research work, an overview of certain types of bioreactors and photobioreactors, the current situation around the climate and the impact of the cultivation of algae on carbon dioxide emissions. The model for temperature control and mass transfer of a plate photobioreactor is created in this work.
Allometric scaling of cellular morphologies in evolution and ecology of unicellular algae
Mezník, Daniel Heliodor ; Neustupa, Jiří (advisor) ; Woodard, Kateřina (referee)
Allometry is a type of relationship between two changing traits of an organism's body. One of the most studied types is morphological allometry, which deals with the change of shape in relation to the size of an organism. The surface area to volume ratio is an immensely important feature that impacts many aspects of a cell's life, and there are ways of changing it. Unicellular algae are a diverse group with many specifics and a wide-ranging impact on the global ecosystem. The goal of this thesis is to introduce allometry and its types and applications with an emphasis on morphologic allometry and changes to the surface area to volume ratio, using specifically unicellular algae as model organisms.
Optimization of extraction of pigments from yeast and algae cells
Šimanský, Samuel ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The presented diploma thesis deals with the extraction and storage stability of lipophilic pigments produced by selected strains of yeasts and algae. In this thesis, there was studied the influence of the selected solvents on the efficiency of extraction, as well as the effect of ambient temperature on the stability of the pigments during storage. The work is divided into two main parts, theoretical and practical part. In the theoretical part knowledge about algae, yeasts and their cultivation parameters is summarized. Furthermore, some information regarding the selected lipid metabolites, their properties and possibilities of application in various branches of industry is mentioned. The practical part deals with the preparation of extracts and stability tests. Extracts were prepared from selected biomass samples in solvents suitable for applications in food industry or cosmetics (ethanol and hexane). Subsequently, the long-term stability tests lasting 4 months and short-term stability tests lasting a total of 28 days were performed on these extracts. The pigments were determined by HPLC and spectrophotometrically, the fatty acid content was determined by GC. For the extraction of pigments from biomass, in the most cases ethanol appears to be the optimal solvent. However, for lipid extraction from biomass, hexane appears to be the optimal solvent for a significant number of samples. In most samples, storage in the freezer showed the most favourable effect on pigment stability, but some samples showed comparable stability even when stored in the refrigerator.
Analysis of glucans in plant and microbial samples
Vít, Radek ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of the diploma thesis is study of glucans production in selected species of yeasts, algae and plants. Cultivation conditions for yeast strains were performed to gain increased production of glucans under different temperature conditions and in media of different composition. Into the set of tested yeasts species strains Saccharomyces cerevisiae (CCY 6646), Sporidiobolus pararoseus (CCY 19-9-6), Phaffia rhodozyma (CCY 77-1), Rhodotorula glutinis (CCY 20-78-26) and Cystofilobasidium infirmominiatum (CCY 17-18-4) were enrolled. Saccharomyces cerevisiae was cultivated as a control strain because of its verified production of -glucans. -glucans were determinated by the enzyme kit K-YBGL Megazyme. For comparison, algal strain Euglena gracilis (CCALA 349), some species of mushrooms (shiitake, oyster mushroom, garden champignon and Jew’s ear) and cereals (wheat, rye, oats, rice and barley) were analysed too. Further, fatty acid content in the yeast cells was determined by the GC/FID. The best producer of yeast -glucans was R. glutinis CCY 20-7-26, which showed the highest biomass production (12-14 g/l) and also a relatively high amount of -glucans (25-30 %), in cultivation at 15 °C in a medium containing yeast extract in combination with ammonium sulphate. The presence of -glucans has been demonstrated in the microalgae, Euglena gracilis CCALA 349, as well as in samples of higher fungi and cereals.
Algal and Cyanobacterial Adaptations to Low Temperature and Desiccation
Jimel, Matouš ; Elster, Josef (advisor) ; Košťál, Vladimír (referee)
Algae and cyanobacteria, due of their evolutionary antiquity, are widely distributed primary producers that can withstand extreme environmental stresses. Low temperature, freezing and melting, and desiccation and rewetting, are common stresses prevalent mainly in polar regions and in winter seasons of temperate areas. In terms of physiological effects, these types of stresses share similar effects or are closely related to one another. Low temperatures and desiccation exert a variety of stresses that need to be negated or lessened by adaptations. Specifically, adaptations to chill, freeze, and desiccation stresses will be discussed, as well as strategies that allow for stress avoidance or resistant morphological adaptations. In this thesis, characteristics, functions and mechanisms of these adaptations and stresses are reviewed, as well as potential biotechnological uses of said adaptations. Key words: algae, cyanobacteria, freezing, chill, desiccation, abiotic stress, cryoprotectants, osmoprotectants, akinetes, cryoinjury
Study of the ETICS surface resistance to biotic attack
Těžká, Adéla ; Žák,, Antonín (referee) ; Žižková, Nikol (advisor)
This diploma thesis deals with the study of resistance of ETICS surface treatments to biotic attack. The theoretical part elaborates a research focused on biotic attack of facades of buildings insulated by contact insulation systems ETICS. Based on the information obtained during the elaboration of the bachelor thesis and further study, the optimization methodology of ETICS surface treatment resistance to biotic attack proposed in 2018 is elaborated. In the practical part, the proposed methodology is verified, evaluated and recommendations concerning the suitability of using the proposed methodology in construction practice are implemented.

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