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Rheology in Technology of Inorganic Binders
Kosár, Petr ; Másilko, Jiří (referee) ; Zmrzlý, Martin (advisor)
This final thesis deals with the study of rheological behaviour of cement pastes. The introductory part describes the composition of Portland cement. Next, a detailed description of mutual interaction between cement and water and the principle of superplasticizer affection follows. The thesis includes a description of properties and interaction of alumina cement with water as well as rheological properties of suspensions and cement pastes. Finally, the theoretical part provides a survey of the elementary methods and equipment for the evaluation of rheological properties of cement materials. The experimental part includes measurement and evaluation of rheological properties (flow curves, plastic viscosity and yield stress) of cement pastes with different composition. The influences of water-cement ratio, amount of superplasticizer and the kind of cement on rheological properties of cement pastes are compared here.
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Effect of lubricant rheology on lubrication film thickness.
Prášilová, Alena ; Šperka, Petr (referee) ; Křupka, Ivan (advisor)
Lubrication is a very important part of mechanical engineering, which ensures high lifetime of machine parts, reduction of friction and wear and also it leads to decreasing of power consumption. In this bachelor`s thesis there is described rheology of newtonian and non-newtonian lubricants and its effect on lubrication film thickness. Measured central film thickness values are compared with theoretical prediction.
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Thermoplastic extrusion of ceramic materials with ionic and mixed conductivity
Kaštyl, Jaroslav ; Matoušek, Aleš (referee) ; Trunec, Martin (advisor)
In the bachelor thesis, an overview of the existing literature focused on thermoplastic extrusion method was worked out and based on the findings; the conditions for extrusion of mixtures with zirconia were optimized in order to produce rods. Great attention was paid to dimensional and shape precision of ceramic parts. Two methods were applied when preparing the ceramic mixtures – mixing and dissolving. These methods have been compared on the basis of the results achieved in rheological measurements of flow properties, microstructure and dimensional accuracy of the sintered rods. Having verified the efficiency of mixture dissolving, this method was used to prepare mixtures with different contents of cellulose and binder.
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Viscosimetry of hyaluronan-amphiphile systems
Trojan, Martin ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
This bachelor thesis investigates the interaction between the polysaccharide sodium hyaluronate (HA) and some amphiphilic molecules. As amphiphilic molecules the aminoacids lysine and 6 – aminocaproic acids were chosen. The presence of the carboxylic group on HA and the aminogroup on the aminoacids suggests electrostatic interaction between these two compounds. This supposal offers the possibility to modificate HA and uses it as a new type of a carrier of bioactive compounds, for example medicals. The HA of two molecular weights (1.75MDa and 70kDa) were chosen for the study of the interactions with the aminoacids. Solutions of HA and stock solutions of the aminoacids were prepared for their mutual mixing in the various volume ratios. The solutions and the mixtures were measured in three types of environment: pure water, 0.15M solution of NaCl and in phosphate buffer (PBS) of pH 6. The interactions were investigated by means of reometry. Our results show, the presence of interactions between HA and the aminoacids mainly in the system consisting the 1.75 MDa HA and lysine in water. As a result of the interactions, a decrease in the viscosity of the mixtures comparing to the HA solutions was observed.
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Rheology of humic gel
Smilek, Jiří ; Gregorová, Eva (referee) ; Klučáková, Martina (advisor)
The main aim of the bachelor thesis was to test several modifications of humic hydrogels’ preparation method and to discuss their effects on mainly viscoelastic properties of resulting materials. Main conditions, tested in the experimental part, were presence of acidic impurities from the gelation step in the gel and an addition of cations with a higher valence during or after the preparation step. The most important evaluated parameters of the materials were inner pH, solid content and mainly basic viscoelastic characteristics.
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The development of self-compacting concrete with fast runs of strength and elasticity modulus
Skřivánek, Michal ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
My bachelor thesis is about a development of self-compacting concrete. The main advantage of this method is a shorter duration of producing strength concrete and also modulus of elasticity. My analysis consists of describing self-compacting concrete properties, methods for speeding up the process of building strength concrete from less effective heating to using advanced concrete admixtures. Further, an important chapter about influence of concrete mixture composition on modulus of elasticity measurements and in-depth analysis of the SCC mixture composition. Theoretical part is ended by a summary of SCC properties in a fresh or hardened state – all experiment specifics are included. In order to deliver a shorter duration of producing strength concrete and modulus of elasticity in early stages of curing, every SCC mixture mentioned in practical part have been carefully created based on achieved theoretical knowledge with a goal to minimize the impact on rheology of concrete mixture.
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MSCR test in dynamic shear rheometer
Střasáková, Monika ; Coufalík, Pavel (referee) ; Kudrna, Jan (advisor)
The laboratory properties of bituminous binders in relation to permanent deformation are described in this bachelor‘s thesis. The principle and procedure of MSCR test will be explained in the theoretical part. The principle of empirical tests (needle penetration, elastic recovery and softening point) will be also described. The properties of four bituminous binders will be evaluated in practical part. The comparison of binders will be performed based on test results.
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Testing of binders of thermal insulations for specific applications on technical appliances
Maňák, Jan ; Kulísek, Karel (referee) ; Petránek, Vít (advisor)
This work focus on testing alcali-activated binders for thermal insulation which could be used for special industry devices. In the beginning of this work is presented example of thermal energy storage where these specific alcali-activated materials can be used. Ensuingly two construction with thermal energy storage tanks are mentioned. Most of the interest aims on ageing and rheological properties of alcali-activated binder. Some rheological methods are also discussed. In the end of this work is added practical experience.
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Flow properties of hyaluronan colloids
Gabrielová, Michaela ; Ptáček, Petr (referee) ; Pekař, Miloslav (advisor)
The purpose of this study is to zoom in implication of flow properties of hyaluronan colloids with respect to physiological role. In the first part I will introduce physical formulation and definition of flow properties and reology, process to its measurement and utilization. In the second part you can read about hyaluronic acid and colloids of its salts. In this part I will focus on first studies of hyaluronic acid throught its occurence to its chemical properties. Within this work I will try to demonstrate interconnection of both subjects.
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