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Diagnostics of reinforced concrete structures
Holbová, Monika ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
This diploma thesis deals with the building survey and diagnosis of the station building of a railway station in Vítkovice. It describes process of survey and evaluation of existing reinforced concrete structures and used diagnostic methods. The survey of the object is described in the practical part of the thesis, which involves location of testing spots, taking the samples for testing from the structure, laboratory testing and evaluation of the results – determination of compressive strength of concrete with classification of concrete and elastic modulus. The last part includes static calculation of selected part of the structure.
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The influence of triaxial deformation of aggregates on properties of concrete
Fójcik, Tomáš ; Kalina, Lukáš (referee) ; Šoukal, František (advisor)
This diploma work takes focus in elastic modulus of unbound granular aggregates, which was determined by repeat load triaxial test and in deformation behaviour of unbound granular aggregates - elastic and plastic deformation. It was examine the propriety of this aggregate for its service as underlying granular material in pavement. Further, there was observed the influence of elastic modulus of unbound granular aggregates on concrete characteristics - compressive and bending strength. Finally, it was observed the influence of individual fractions of aggregates on its elastic modulus and strength of concrete.
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Rheological properties of gelatin-based gels for ultrasound brain phantom
Bojňanská, Terézia Marianna ; Šnejdrová, Eva (advisor) ; Holas, Ondřej (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRALOVE DEPARTMENT OF PHARMACEUTICAL TECHNOLOGY Author: Terezia Marianna Bojnanska Supervisor: PharmDr. Eva Snejdrova, Ph.D. Title of diploma thesis: Rheological properties of gelatin-based gels for ultrasound brain phantom The diploma thesis deals with the evaluation of the viscoelastic properties of gelatin gels modified by addition of glutaraldehyde and glycerol using a rheometer with goal to verify the suitability of tested materials for their intended use as ultrasound brain phantoms. The theoretical part deals with gels in general and is focused on gelatin gels as a possible basic component of ultrasound phantoms, and the possibilities of characterizing gels as viscoelastic systems using methods of oscillatory rheometry. Gelatin gels of different concentrations (5; 7,5 and 10%) with the addition of glutaraldehyde and glycerol were characterized by complex modulus, complex viscosity, yield stress, phase angle. Temperature stability of the samples in the range from 20 to 50řC was tested. All tested gels were viscoelastic solids with a clearly defined linear-viscoelastic region, which is confirmed by phase angle values close to 0ř. With the increasing concentration of gelatin the values of the complex modulus increased, increasing...
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Rheological properties of agar-based gels for ultrasound brain phantom
Schneiderová, Marie ; Šnejdrová, Eva (advisor) ; Holas, Ondřej (referee)
CHARLES UNIVERSITY FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ DEPARTMENT OF PHARMACEUTICAL TECHNOLOGY Author: Marie Schneiderová Supervisor: Phar Dr Eva nejdrová Ph D Title of diploma thesis: Rheological properties of agar-based gels for ultrasound brain phantom The diploma thesis deals with the evaluation of the rheological properties of agar gels on a rotational rheometer. The theoretical section contains the characterization of gels, their distribution, properties and use in pharmacy, describes agar and its characteristic properties. It also provides brief information on phantoms and describes the agar-based phantom in more detail. The principles of oscillation tests and their evaluation are described. Twelve gels with different agar concentrations were tested: a series of gels without glycerol and a series of gels with glycerol. The structure of the gels was characterized by the test Evaluating product texture using oscillatory testing and te perature stability in the range of 20 ř C to 40 ř C by the Single frequency strain controlled temperature ramp test. The viscoelastic properties of pig brain tissue were characterized by the same tests. The gel structure was confirmed in all samples tested. The stiffness expressed by the value of the complex modulus G * increases with the agar concentration....
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Oxygen-strengthened biomedical beta titanium alloys
Preisler, Dalibor ; Stráský, Josef (advisor)
Oxygen strengthened biomedical beta titanium alloys Beta titanium alloy Ti-35Nb-6Ta-7Zr-0.7O (wt. %) exhibits a low Young's modulus and high strength thanks to interstitial strengthening effect of oxygen. These mechanical properties are promising for implant production. In this thesis, the aforementioned alloy is thoroughly studied in conditions prepared by various thermomechanical treatments, namely: material after casting, hot compression testing, die-forging, hot rolling and finally, cold-swaged and annealed condition. Mechanical properties and microstructure of prepared conditions are studied with special interest of enhancing the fatigue performance that is poor after casting due to porosity and large grains. The hot rolling was shown to improve the fatigue performance significantly, mainly through grain refinement. It is shown that by combining the effects of cold-swaging and recrystallization annealing, extensive refinement of grain structure can be achieved. Industrial aspects of implant production by the studied methods were discussed. In the second part of the thesis, the possibility of lowering the Young's modulus by reducing the beta phase stability (by reducing of Nb and Ta content), while retaining high strength caused by high interstitial oxyen content is explored. Several alloys were...
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Oxygen-strengthened biomedical beta titanium alloys
Preisler, Dalibor ; Stráský, Josef (advisor)
Oxygen strengthened biomedical beta titanium alloys Beta titanium alloy Ti-35Nb-6Ta-7Zr-0.7O (wt. %) exhibits a low Young's modulus and high strength thanks to interstitial strengthening effect of oxygen. These mechanical properties are promising for implant production. In this thesis, the aforementioned alloy is thoroughly studied in conditions prepared by various thermomechanical treatments, namely: material after casting, hot compression testing, die-forging, hot rolling and finally, cold-swaged and annealed condition. Mechanical properties and microstructure of prepared conditions are studied with special interest of enhancing the fatigue performance that is poor after casting due to porosity and large grains. The hot rolling was shown to improve the fatigue performance significantly, mainly through grain refinement. It is shown that by combining the effects of cold-swaging and recrystallization annealing, extensive refinement of grain structure can be achieved. Industrial aspects of implant production by the studied methods were discussed. In the second part of the thesis, the possibility of lowering the Young's modulus by reducing the beta phase stability (by reducing of Nb and Ta content), while retaining high strength caused by high interstitial oxyen content is explored. Several alloys were...
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The use of the secondary aggregates to pavement
Hurtiš, Maroš ; Hrbek, Kamil (referee) ; Stehlík, Dušan (advisor)
The master thesis deals with the possibilities of using waste aggregate from main rock production to hydraulically bound mixtures, witch are used in base and sub base pavement. The theoretical part describes conditions and properties of bound mixtures, aggregates and cement. The practical part describes the process of design, mixture preparing and laboratory test carried out on them. The bound mixtures are testing in compressive strength, frost and water resistace and resilient modulus.
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Effect of aggregate type on lime mortar rheology
Vozák, Rastislav ; Rovnaník, Pavel (referee) ; Vyšvařil, Martin (advisor)
The subject of this bachelor thesis is examining the effect of aggregate type on lime mortar rheology. In the theoretical part, the thesis describes types of liquids and basic rheological quantities. Afterwards there are described some of the rheological behaviour models of non-Newtonian fluids. Furthermore, the theoretical part characterizes measurement of the flow, devices used for the measurement including the oscillatory measurement and its individual modes. Scientific literature was used to describe the rheology of the lime mortars and it covers the effect of different additives on the rheological behaviour. There is also characterized the effect of aggregate on the properties of lime mortars. The experimental part talks about the effect of three various kinds of aggregate on rheological prop-erties of the fresh lime mortar. The chemical composition of aggregates and their granulometry was determined. Subsequently, flow measurements were carried out and evaluated into flow curves. The yield stress, coefficient of consistency and flow index were assayed. In the oscillatory measurement there were measured complex, elastic and viscous modulus and loss factor.
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