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Utilization of mica separated from washed kaolin
Vaculík, Josef ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
The Master’s Thesis aims to laboratory test the possibilities of utilization mica separate, which arises during the process of floating kaolin as a by-product together with sand. Mica and sand are then separated by flotation or vibration. The mica separate thus formed was subjected to analysis. XRD and heating microscopy methods were used for analysis. Subsequently, experiments with mica separation as a filler in composites based on epoxy resins were set up and performed. Furthermore, the separate was tested as a part of plasters and visual building elements. Last but not least, the separate was mixed into the ceramic, which was then subjected to firing in the selected mode. The diploma thesis provides a comprehensive overview of the above-mentioned possibilities of using mica separation, which is based on a sufficient amount of experimental data.
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Design of Hairdryer
Jankejechová, Eva ; Bukvald, Jiří (referee) ; Rubínová, Dana (advisor)
Object of my thesis is the analysis and design of hair dryer regards to the aesthetic, environmental and technical requirements. The aim of the design is to create hair dryer, which manipulation will be comfortable in ergonomic way and the shape will be enriched by another functional elements.
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Determination of acoustic properties of brick body
Hladík, Lukáš ; Skotal, Zbyněk (referee) ; Sokolář, Radomír (advisor)
Bachelor thesis deals with the possibility of increasing the index of the air soundless the wall brick forms. The theoretical part summarizes the present knowledge in the field of acoustic properties of the ceramic shard and also the theory and methodology of the appraisal the index of the air soundless of building materials. Then there is the possibility of using ultrasound for indirect appraisal of the index the air soundless of a brick shard described both in the theoretical part in the form of a research of existing sources and in the practical part.
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Diagnostic Methods Suitable for Monitoring of Drying Process of Brick Product
Sarvaš, Ondřej ; Sokolář, Radomír (referee) ; Nevřivová, Lenka (advisor)
This work deals with the study of diagnostic methods suitable for monitoring of the drying process of brick raw materials. Based on the extensive literature search, several parameters are selected, which are appropriate to monitoring during drying. In addition, a methodology for measuring these selected parameters is proposed. In the experimental part, the use of all described methods is gradually verified on the brick raw material with and without shortening additive (also known as grog). Was carried out: measurement of the surface temperature in the climatic chamber, determination of humidity distribution in the sample, determination of moisture diffusivity, determination of tensile strength, determination of ultrasonic wave velocity and determination of dynamic E-modulus of elasticity. Results of experiments and the gained experiences show, that at least two of the above-mentioned monitoring methods are very appropriate and beneficial – determination of moisture diffusivity and determination of tensile strength. In the work was described in detail the procedure of determination of moisture diffusivity of material. The dependence of moisture diffusivity on the moisture content of the dried material, has been described. Also, differences between raw material with grog and without grog has been described. As part of the practical verification of the experiment designed to determine the tensile strength at different humidity levels of test samples. A new shape of the test specimens and a new device were designed to allow them to be attached to a hydraulic press. The results of this work show that the tensile strength of the ceramic green bodies is primarily dependent on the moisture content of the material. The type of raw material almost does not affect the tensile strength.
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Thermophysical and electrical properties of illite-based ceramics
Csáki, Štefan ; Dobroň, Patrik (advisor) ; Koštial, Pavol (referee) ; Labaš, Vladimír (referee)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
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Thermophysical and electrical properties of illite-based ceramics
Csáki, Štefan ; Dobroň, Patrik (advisor)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
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Comparing the Results of Probability of Ceramic Head Fracture According to Weibull's Theory with Inclusion of One or Three Principal Stresses
Kovář, J. ; Fuis, Vladimír
This paper focuses on the assessment of probability of ceramic head hip joint endoprothesis fracture.\nThe Weibull's weakest link theory with inclusion of one or all three principal stresses was used for calculations of probability of failure and the results were compared. The test of head of the hip joint endoprothesis according to ISO 7206 was modelled. Three variants were considered. In the first variant, the head of hip joint endoprothesis ended up without any imperfections from ideal geometry. In other two variants, the ceramic head had shape imperfection from nominal conicity. Principal stresses needed for the calculation of probability of failure were calculated by finite element method. The results with the use of linear and quadratic solid elements were compared and better option was chosen for the next calculations. The influence of allowed penetration, density of the mesh on the results of stresses and probability of failure was assessed. The Gaussian quadrature of 13th order was used for integration over the surface of unit hemisphere in space of principal stresses which was needed for computation of probability of failure with inclusion of all principal stresses. The influence of imperfection from nominal conicity on probability of failure of the head hip joint endoprothesis was calculated and the relative difference between the results of Weibull's weakest link theory with the inclusion of one or all three principal stressed was analyzed.
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DPF for SI Engines
Pohludková, Lenka ; Prokop, Aleš (referee) ; Dundálek, Radim (advisor)
This bachelor thesis deals with gasoline particulate filters. Emissions of internal combustion engines and their impact on air pollution and human health, especially the impact of particulate matter, are discussed. It also describes what these filters are made of, where they are located in the car, and explains the principle of their function and regeneration.
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Preparation of nanocrystalline ceramic materials made from zirconia oxide
Vlček, Ondřej ; Prajzler, Vladimír (referee) ; Šťastný, Přemysl (advisor)
Bachelor thesis is focused on preparation of nanocrystalline stabilized zirconia ceramics. The theoretical part is dedicated to zirconia ceramics. Theoretical part describes and unveil the transformation-induced toughening mechanism in partially stabilized zirconia ceramics, the processing routes of these ceramic materials and their utilization. The research part describes preparation of yttria partially stabilized nanocrystalline zirconia ceramics by slip casting method.
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