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Spatial heterogeneity of physico chemical parameters and phytoplankton along the longitudinal profile of the Římov Reservoir
NOVOTNÁ, Jitka
In 2011, vertical and longitudinal gradients of temperature, oxygen, pH, conductivity and chlorophyll were measured in the Římov Reservoir. Relative distance model was employed to evaluate spatial heterogeneity of parameters measured along the longitudinal axis of the reservoir. The inflow part comprised 15 % of the overall reservoir length and was characterized with temperature, pH and chlorophyll values lower than the rest of the reservoir. Highest chlorophyll and dissolved oxygen concentrations along with pH were measured in the transition zone constituting 40 % of the reservoir length. Lacustrine zone with low chlorophyll concentration accounted for 45 % of the reservoir. It was characterized with pronounced metalimnetic and hypolimnetic oxygen minima during summer as well as the marked increase in conductivity towards bottom.
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Self-assembled layers based on silicon
Bábík, Adam ; Veselý, Michal (referee) ; Čech, Vladimír (advisor)
Thin film deposition, characterization and properties of self-assembled monolayers based on silicon were studied with emphasis on the SA monolayers deposited from vinyltriethoxysilane and vinyltrichlorsilane. The thesis is aimed at basic properties of the SA monolayer and explanation of its growth. Methods and techniques used for analysis of the monolayer were described as well. Contact angle measurements and an evaluation of the surface free energy are depicted in details. The deposited SA layers were observed with respect to their chemical composition and surface morphology by X-ray photoelectron spectroscopy (XPS), ellipsometry and atomic force microscopy (AFM).
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Conversion of family farm on organic farming system
ŠVOJGR, Josef
The thesis is focused on the evaluation of current situation of farming and making a plan for a transition of Angus farm to an organic way of farming in plant and stock farming. During the period of conversion that takes 2 years for arable land, meadows and grazing the farmimg has to be in compliance with the law No. 344/2011 about organic farming. The theoretical part contains basic information about organic farming history in the Czech Republic, basic concept specification such as organic farming, ecofarm, organic product, organic food. The other information deal with the main goals of organic farming, legislation, check, certification and last but not least the subsidy of organic farming. The second part of the thesis analyses the current situation of the farm where the plant farming structure, stock farming structure, used machinery and agrotechnological operation, staffing, balance of nutrients, balance of forage, chemical means using, and SWOT analysis of the current situation are described. In the final part of the thesis there is offerred the structure of plant and stock farming for the conversion where balance of nutrients, balance of forage, staffing, operation modernization, introducing the agritourism, economic evaluation and SWOT analysis of the current situation after the conversion are described.
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Divergent organohalide-respiring consortia in PCB-contaminated sediments
Mikešová, Martina
This study is focused on one particular group of the halogenated molecules called polychlorinated biphenyls (PCBs) - synthetic, organic compounds derived from biphenyl with bound chlorine atoms. Depending on the position and number of the chlorine atoms, there are theoretically 209 individual PCB congeners. Although PCBs production was brought to a halt thirty years ago, recalcitrance to degradation makes them a major environmental pollutant at a global scale. Large amounts of PCBs were produced in several countries, and former Czechoslovakia belonged to the ten major world producers. Despite the PCB congener resistance to chemical modification, bacterial process of reductive dechlorination, named organohalide respiration (OHR), was shown to be efficient in the dechlorination of extensively chlorinated PCB congeners and a prerequisite step towards their subsequent complete mineralization by aerobic bacteria. In our study, reductive dechlorination of polychlorinated biphenyls (PCBs) was assessed using long term anaerobic microcosms. The microcosms were inoculated with highly contaminated with weathered Delor sediments, sampled from the efflux channel of the former PCB manufacturer Chemko Strazske. After one year of cultivation the chemical analysis showed a degradation of up to 36 % of the highly...
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Fatigue crack growth and delamination in fiber metal laminate (GLARE) during loading with positive mean stress
Chlupová, Alice ; Kozák, Vladislav
The aim of the paper is to present the results of a study on the damage of fiber metal laminate (GLARE) subjected to the low cycle fatigue loading with positive mean stress. The fatigue crack initiation and growth was observed on the surface of notched specimens and then the individual layers of fatigued specimens were removed by chemical etching and polishing to obtain data about cracks length and delamination shape and area. Mechanism of initiation and crack growth in this type of materials differs from homogeneous monolithic materials. The fatigue life in term of number of cycles to crack initiation depending on amplitude of local plastic deformation and local stress in the notch root was evaluated.
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Studying Formation and Kinetics of Belite Clinker Hydration
Halešová, Adéla ; Walter, Martin (referee) ; Gazdič, Dominik (advisor)
DIPLOMA THESIS IS DEVOTED TO THE STUDY OF PREPARATION OF PURE BELITE CLINKER FOR THE POTENTIAL INCREASE OF KINETICS OF THE HYDRATION PROCESS BY CHEMICAL ACTIVATION. THE THESIS OF THIS WORK IS BASED ON RESEARCH FINDINGS CONCERNING BELITE CLINKER AND RESEARCH AT THE INSTITUTE OF THD. THE THESIS AIMS TO DESIGN COMPOSITION OF THE RAW MEAL BURNING BELITE, FOLLOWING MODIFICATION BY SULPHATE AND POTASSIUM CARBONATE IN ORDER TO POTENTIALLY INCREASE THE REACTIVITY OF THE BURNT BELITE CLINKER AND THE LABORATORY FIRING OF PREPARED SAMPLES. THE LAST STEP WAS TO ASSESS THE MINERALOGICAL COMPOSITION OF BURNED SAMPLES XRD ANALYSIS AND FOLLOWING COMPARISON CELL PARAMETER OF BELITE WITH AND WITHOUT ADDED MODIFYING ADDITIVES.
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Technology of monofilamentous fibers based on oxidized hyaluronic acid
Běťák, Jiří ; Mráček, Aleš (referee) ; Burgert, Ladislav (referee) ; Klučáková, Martina (advisor)
Předkládaná dizertační práce se zabývá vývojem technologie výroby nového typu biodegradabilních vláken na bázi oxidované kyseliny hyaluronové. V rámci práce je postupně představován vývoj jednotlivých jednotkových operací výroby, jejichž správné porozumění a schopnost jejich řízení jsou klíčové pro žádaný chod celé vícestupňové technologie. V rámci práce je představen nezbytný vývoj technologického zařízení, průběžně konstruovaného pro účely laboratorního testování a následně až po samotnou linku pro finální výrobu vláken, která byla realizována v roce 2015. V rámci dizertační práce jsou dále navrhovány možnosti dodatečné chemické úpravy vláken s ohledem na zvyšování jejich stability ve vlhkém prostředí. S ohledem na cílené aplikace vláken pro vnitřní chirurgické implantace, jsou v práci vlákna též hodnocena z hlediska jejich materiálové biokomaptibility (toxicity).
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Frustrated Lewis pairs-assisted reduction of carbonyl compounds
Marek, Aleš ; Pedersen, M. H. F.
An alternative and robust method for the reduction of carbonyl groups by frustrated Lewis pairs (FLPs) is reported in this paper. With its very mild reaction conditions, good to excellent yields, absolute regioselectivity and the non-metallic character of the reagent, it provides an excellent tool for 1H, 2H as well as 3H chemistry. It is a new strategy for the one-pot synthesis of aromatic alcohols selectively labeled with heavy isotopes of hydrogen.
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