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Changes of slag particles during its alkaline activation
Petrů, Ludmila ; Hrubý, Petr (referee) ; Bílek, Vlastimil (advisor)
This bachelor thesis deals with changes of slag particles during its alkaline activation. The altered parts of the slag as well as the course of the alkaline activation varies depending on the activator used, and therefore suspensions of blast furnace slag in sodium hydroxide, water glass, sodium carbonate and, for comparison, in water were prepared. Slag particles were isolated from these suspensions at selected time intervals (5 min, 30 min, 1 h, 2 h, 5 h and 24 h) for particle size analysis and evaluation of BET specific surface. After solidification, the microstructure of the samples was observed using an electron microscope. To better assess the reaction processes, the pore solution was isolated from the suspensions and its composition was analyzed using optical emission spectrometry in inductively coupled plasma. The hydration process was monitored using isothermal calorimetry.
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Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions
Murmiliuk, Anastasiia ; Štěpánek, Miroslav (advisor) ; Šachl, Radek (referee) ; Hoffmann, Ingo (referee)
Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions Abstract: This PhD thesis is dedicated to the study of polyelectrolytes and their self-assembly in aqueous solutions. The morphology and ionization state of individual polymer chains were investigated as well as their co-assembly with oppositely charged species. First, the charge regulation of short and long weak polyelectrolytes in aqueous solution was investigated to deeper understand their pH-responsive properties. The changes of ionization degree and charge of oligopeptides composed of 5 amino acids with acid side-chains and 5 with basic side chains were followed upon varying the pH in order to reveal the effect of interactions between the like-charged and oppositely charged groups. It was shown that intra-molecular electrostatic interactions and conformational flexibility caused the suppression of the total charge and enhancement of ionization of the peptides. To get an insight into the distribution of local H+ concentration in the proximity of a polyelectrolyte chain, a modified polyelectrolyte structure was used with a fluorescent pH- indicator, covalently attached at the end of the chain. Ionization of the pH-responsive fluorophore revealed its effective pK which was compared with the local...
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Preparation of Ethyl 2-acetoxypropanoate
Kučerová, Eliška ; Pospíšilová, Aneta (referee) ; Figalla, Silvestr (advisor)
The bachelor thesis focuses on the preparation of ethyl 2-acetoxypropanoate as a potential nonpolar biosolvent. Selected preparation should provide the highest yield possible. For this purpose, a theoretical review of possible syntheses was developed, with emphasis on syntheses based on acetylation of ethyl lactate. The experimental part of the work then focuses in more detail on the possibility of isolating ethyl 2-acetoxypropanoate from the reaction mixture. Product isolation was verified by fractional distillation and extraction method. In the isolated product, the basic physical properties were determined and the spectrum measured by Fourier transformation infrared spectroscopy. Furthermore, the hydrolytic stability of ethyl 2-acetoxypropanoate was investigated and a series of calorimetric measurements were performed. From these measurements, the effect of reaction temperature on reaction rate and product conversion and the effect of catalyst presence was assessed.
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Study of single stranded DNA by biophysical techniques
Svoboda, Jakub ; Schneider, Bohdan (advisor) ; Novák, Petr (referee)
DNA is the fundamental functional molecule of all domains of life. One of its characteristics is the ability to self-associate to form a double stranded helix. Nevertheless, even single stranded DNA can form non-canonical structures such as hairpins, triplexes or tetraplexes. One of the interesting single stranded sequences are REP elements. These sequences form a part of bacterial transposable elements, so-called insertion sequences, which can be found in a great number of copies in wide range of bacterial species. This thesis studies structure and properties of selected REP sequences. It presents the results of spectral measurements by technique of circular dichroism, melting curves from differential scanning calorimetry, and monocrystal diffraction data. Key words Single-stranded DNA, crystallography, circular dichroism, calorimetry, transpozone, REP elements, insertion sequences.
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Development of Web-Based Computational Tool for Analysis of Microcalorimetry Data
Nedeljković, Sava ; Musil, Miloš (referee) ; Sumbalová, Lenka (advisor)
Proteins are organic molecules made up of amino acids which are present in all living organisms. They are the main building blocks of life. Study of protein stability has great application in pharmaceutical, biochemical and medical industries, which makes it in high demand. Stability of a protein and many other properties can be determined by observing its unfolding mechanisms. Differential Scanning Calorimetry (DSC) has proven to be a very precise method for this task. The main goal of this thesis is to improve functions of software CalFitter, which analyses data obtained from DSC experiments. The new functionality of the software enables it to automatically calculate initial parameters, which are needed for successful analyses.
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Self-Assembly in Mixture of Surfactants and Stimuli-Responsive Polymers with Complex Architecture
Bogomolova, Anna ; Filippov, Sergej (advisor) ; Štěpánek, Miroslav (referee) ; Hanyková, Lenka (referee)
Title: Self-assembly in mixture of surfactants and stimuli-responsive polymers with complex architecture Author: Anna Bogomolova Department: Physical and Macromolecular Chemistry Supervisor: PhD. Sergey K. Filippov, IMC AS CR, v.v.i. Supervisor's e-mail address: filippov@imc.cas.cz Abstract: The issue of construction of complex multi-block copolymers is currently one of the most researched areas. It became a logic consequence of the continuous development in polymer chemistry. Nowadays, a great interest is attracted to multi- responsive block copolymers. As a rule, they consist of hydrophilic, hydrophobic and responsive blocks. That responsive block can be either thermo-sensitive or pH-sensitive as well as sensitive to some other external stimuli. In the present work, we will try to cover topic of stimuli-responsive block copolymers and their interactions with different types of surfactants. Understanding of polymer/surfactant interactions can be a crucial step for future modeling of drug/polymer or protein(DNA)/surfactant interactions. There is a great interest in the investigation of polymer-surfactant interactions. However, while the homopolymer-surfactant interactions are characterized well enough, the same interactions for block copolymers are poorly described. The main development in the latter topic...
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Study of intermolecular interactions by isothermal titration calorimetry
Pšenáková, Katarína ; Obšil, Tomáš (advisor) ; Alblová, Miroslava (referee)
Calorimetric methods are used to studying the mechanism of regulation and control of biological processes at the molecular level. Isothermal titration calorimetry (ITC) is used for monitoring the heat exchange of molecular interactions in an environment with constant temperature. This method is also preferred because of its ability of direct measurement of thermodynamic parameters associated with complex formation. ITC measures mostly the energetics of biochemical reactions or molecular interactions protein-protein, protein-ligand, or enzyme-substrate. Main goals of this bachelor thesis were: (I) to acquire working skills with nano isothermal titration calorimeter; (II) to prepare the DNA-binding domain of human transcription factor FOXO4 (FOXO4-DBD); and (III) to study thermodynamic aspects of the interaction between FOXO4-DBD and the double-stranded DNA containing specific binding motif. FOXO4 protein is one of the four members of a "O" subgroup of forkhead transcription factors FOX, which play an important role in many cellular processes including stress resistance, age control and oncogenesis. Forkhead DNA- binding domain recognizes sequences containing the core motif 5'-(A/C)AA(C/T)A-3' with the binding stoichiometry 1:1. Results of this bachelor thesis show that FOXO4-DBD binds the...
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Reological properties of cement pastes modified by amorphous SiO2
Zimmermann, Štěpán ; Rovnaník, Pavel (referee) ; Vyšvařil, Martin (advisor)
The subject of this thesis are the rheological properties of cement paste with the addition of amorphous silicon dioxide. The basic rheological parameters are that describe the behavior of cement pastes in the fresh state. The work also included rheological tests including measurement principle and method of evaluation. Effect of mineral admixtures with high content of amorphous SiO2 is summarized the available scientific articles. In the experimental part, the effects of impurities with a high content of amorphous SiO2 on the rheological properties of fresh cement paste. It was tested by substitution of up to 10 % by weight of cement in the cement pastes mineral admixtures of different chemical composition, particle size and pozzolanic activity. Flow measurement was measured yield value, viscosity, and flow index. The stability of cement pastes was investigated oscillatory measurements. To complement the behavior pastes in the fresh state was determined by calorimetry. Test results were compared with those determined by reference samples and compared the effect of various ingredients.
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Optimalization of Technological Properties of Cement Sand Mixtures
Burianová, Klára ; Jelínek, Petr (referee) ; Tegel, Michal (referee) ; Rusín, Karel (advisor)
The work deals with optimization of the technological properties of cement-sand mixtures. The main objective is to find the correct mixture of the individual components which contribute to the rapid solidification of the mixture, hence shorter dismantling. The content is also of a method of measuring and recording during the plasticity of the mixture. Also assessment of the velocity of hydration heat cement mixture in the initial stage of the solidification process in the course of the strength properties of the mixture. To assess these phenomena was used calorimetric method used for measuring hydration heat cement mixture. Further measurements plasticity mixtures and mechanical and physical methods for measuring the compressive strength with the help of a measuring instrument LRU-D.
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Microcalorimetric study of bacterial degradation of oil and its products
Bola, Tomáš ; Benešová, Pavla (referee) ; Krouská, Jitka (advisor)
This bachelor thesis deals with a study of the oil degradation as one of the possible products of petroleum using bacterial stems Pseudomonas Putida a Pseudomonas Chlororaphis. The work is motivated by the research of usability of a method which has not been used for those purposes so far – calorimetric analysis. Using IČ spektrometry (ATR), calorimetry and UV-VIS spectrometry was studied a degree and a character of interactions. Calorimetric analysis showed that the Pseudomonas Putida has bigger abbility of the degradability than Pseudomonas Chlororaphis. There was also detected that the optimal concentration for more effective degradation of oil fuel is 5 g/l and 20 g/l. By measurement of the absorbance deppending on time was verified that the bigger is the concentration of the sample, the higher is the resulted absorbance. Using UV-VIS analysis was determined a quantity of biomass. Using IČ spectometry in the ATR mode (reduced reflectance) was detected structure of the sample and also verified that the bacterial cultures Pseudomonas Putida and Chlororaphis degradated entire amount of petroleum.
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