National Repository of Grey Literature 39 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Utilisation of already deposited energy by-products in cement production
Lukášek, David ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis focuses at study of deposited high-temperatured fly ash and its utilization in production of cement. The theoretical part of the bachelor thesis deals with the production and division of cements. The individual advantages and disadvantages of high-temperature and fluid fly ash when added to cements are addressed. The theoretical knowledge was used to design subsequent experiments. The conclusion of the theoretical part of the work deals with pozzolans. The main content of the experimental part was the analysis of raw materials and subsequent analysis of the mechanical properties of the prepared mixtures. The experiments were designed in accordance with valid standards.
Combined aluminium-silicon based sol-gel binding system for refractory
Taraba, Vojtěch ; Koplík, Jan (referee) ; Švec, Jiří (advisor)
The following piece of work deals with the use of a combined aluminium-silicon based sol-gel binding system for refractory. The effect of different gelling agents on the gelation process was observed and rheometric measurements were performed for MgO. After optimizating the drying process, the resulting gel was characterized by thermal analyses, based on which the firing temperatures were selected. Qualitative analysis of the gels fired to the selected temperatures was performed using FTIR. Using XRD, the semi-quantitative phase composition of the samples was monitored as a function of firing temperature. The topography of the test bodies prepared based on results of the previous analyses was later observed using a scanning electron microscope.
Thermal analysis methods application for characterisation of sol-gel binding system for ceramic materials
Cesnek, Ľuboš ; Másilko, Jiří (referee) ; Švec, Jiří (advisor)
The master thesis deals with the study of the binder system of silica sol and its characterization mainly by methods of thermal analysis. The master thesis also uses method of rheology to determine the gelatinization time, method of TG/DTA do analyse the exo and endothermic effects during heating, the method of FT-IR to quickly determine the composition of samples, method of XRD to analyze phase composition of the samples and the method of SEM to observe the topography of the samples. MgO is used as a gelling agent, reactive alimina is used as a filler.
Influence of fumed silica on the properties of ultra-high performace cement composite
Hrbáčová, Markéta ; Švec, Jiří (referee) ; Novotný, Radoslav (advisor)
This diploma thesis deals with the properties of concrete based on reactive powdered materials. Pyrogenic nanosilica (Aerosil 200, Aerosil 380) was added to the concrete in various volume ratios. The aim was to design and prepare a series of samples in order to determine their basic properties, and to determine the behavior of selected samples during penetration by a high-speed projectile compared to the reference sample. In order to determine the strength of the samples, compression and tensile bending tests were performed. The so-called multihit test was used to determine ballistic resistance. The differential effect factor was also determined experimentally and compared with the reference sample. An electron microscope was used to monitor the behavior of the fibers in the binder as well as the binder itself. Hydration curves for individual samples were generated using calorimetric measurements. The bulk density of the samples and the spills during their preparation were also monitored. The resulting strength of the nanosilica samples did not show higher values compared to the reference sample. The results of the multihit test did not show considerable changes compared to the reference composite.
New markers of colon cancer evolution in ulcerative colitis
Švec, Jiří ; Kment, Milan (advisor) ; Keil, Radan (referee) ; Hampl, Aleš (referee)
Background: Long-standing ulcerative colitis (UC) has an increased risk of evolving into colorectal cancer (CRC) and upregulated expression of cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), survivin, telomerase catalytic subunit (TERT), integrin-linked kinase (ILK) and transcription factors c- MYB and TCF-4, has been implicated in the development and progression of sporadic colorectal cancer. Nevertheless much less is known about their role in the process of UC-associated colon carcinogenesis. Methods: We analyzed the gene expression of these markers during the transition of colonic mucosa from chronic inflammation to epithelial neoplasia in biopsies of UC patients using quantitative real-time polymerase chain reaction and immunohistochemistry, and compared the expression profiles of this gene panel in samples of patients with CRC and in human tumor xenografts of SW620 malignant colonic cells. Additionally, we determined the expression of these genes in mouse models of sporadic and colitis-associated CRC in A/J and ICR mouse strains using quantitative RT-PCR and laser microdissection. Results: The transcript levels of survivin, c-MYB, COX-2, iNOS, and TCF-4 showed statistically significant increase during neoplastic transformation of UC-patient colonic mucosa, whereas TERT and ILK...
Influence of chemical agents on stability of PTC ceramics based on BaTiO3
Koller, Kryštof ; Švec, Jiří (referee) ; Sita, Zdeněk (advisor)
The thesis deals with the study of the influences of selected groups of chemical agents on the stability of PTC ceramics based on BaTiO3. The experimental part includes elaboration of methodology for determination of these influences, their evaluation, including the hypotheses for their description, and evaluation of groups of chemical agents having these influences.
Preparation of yttrium based chemically bounded phosphate ceramics
Uher, Samuel ; Šiler, Pavel (referee) ; Švec, Jiří (advisor)
The thesis is focused first on the research of literature on the topic of phosphate ceramics and then on the search for a suitable synthesis of phosphate binder based on Y2O3-P2O5-H2O and characterization of the resulting products. Various types of syntheses were prepared with subsequent characterization of the phase and chemical composition of the final products. The samples were measured on an electron microscope to determine their surface morphology and also element maps were obtained. The samples were also analyzed by heat microscopy to determine the temperature behavior of the samples. After measurement on a heat microscope, the samples were measured again on an electron microscope, in order to detect changes caused by the action of high temperatures, in particular to assess the presence of binder or sintered phases.
Aplikace pro získávání názorů z uživatelských recenzí
Švec, Jiří
This paper describes some current methods for customer's opinion mining and text processing. Application architecture is created along with database structure. Based on this architecture, new application is implemented. Emphasis is placed on automated downloading and processing of customers' reviews with opinion extraction and user-friendly presentation. Part of this paper is dedicated to optimizing the application for better efficiency and speed boost.
Inorganic thermal insulation material for masonry elements
Sedlačík, Martin ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This master’s thesis deals with preparation of foam glass and explores the possibilies of utilization of this material as an inorganic thermal insulating filler of fired hollow bricks. Foam glass was prepared via powder sintering method from waste packaging glass, using limestone and graphite as foaming agents. After inital analysis of raw materials, the effect of mixture composition and different processing parameters on bulk density, pore size and morphology of foam glass was investigated. Last but not least, different ways of manufacturing thermal insulating bricks, by preparation of foam glass directly in the cavities of fired hollow bricks, were tested.
Alumina based refractories for noncement application
Böhm, Petr ; Dlabajová, Lucie (referee) ; Švec, Jiří (advisor)
The thesis deals with the possibility of bonding the ceramic mixture by a sol-gel method, Colloidal alumina was used as the sol and the gelation was performed by changing the ionic strength or pH. The influence of different gelling agents (NaCl, NH4Cl, NH3, MgO a CO(NH)) on the gellation time and on the course of the gelation was compared. The aim of the work is the preparation of refractory monolith with the highest packing desity possible, which was solved by modeling the granulometric curve of the solid part of the ceramic mixture based on alumina. The thesis also describes the behavior of prepared gels during thermal processing of ceramics. Subsequently the resulting structure of prepared ceramic bodies was monitored.

National Repository of Grey Literature : 39 records found   1 - 10nextend  jump to record:
See also: similar author names
8 ŠVEC, Jakub
13 ŠVEC, Jiří
2 Švec, J.
1 Švec, J. G.
8 Švec, Jakub
12 Švec, Jan
4 Švec, Jaroslav
3 Švec, Josef
12 Švec, Ján
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