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Assessment of state banks and a proposal for stabilizing the selected dam reservoir
Kroček, Tomáš ; Pelikán, Petr (referee) ; Šlezingr, Miloslav (advisor)
This thesis covers the state assessment of the selected bank sections of dam reservoirs Vranov and Boskovice. Data used and processed in this thesis were acquired by visiting both sites several times in order to perform measurements and make photographic documentation. Futhermore, data on reservoirs' water levels from 2000-2011 provided by Povodí Moravy s.p. were used. In order to determine bank line regression, the above-mentioned data were processed using the Šlezingr's modification of the method of abrasion terminants determination. Results for dam reservoirs Vranov and Boskovice are then compared with results of dam reservoir Brno, which were produced by the author within the framework of his bachelor thesis using the same method. At the end of the thesis, the author presents several possible forms of stabilization and protection of disrupted banks of dam reservoirs, including their drawings.
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Wear resistence of cladding
Pagáč, Aleš ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The subject of this Diploma thesis was study of wear resistant deposits, including appropriate basic and filler materials and welding technologies suitable for a particular application of hard carbide overlays of blade mixer for foundry sand. Analysis of suitable filler materials focused on extreme abrasion and select tungsten carbide hardfacing, together with a selection of appropriate overlays welding methods for welding tungsten carbide, including the conditions and parameters surfacing. The practical part deals with the design and evaluation of the experiment, three samples welding of non-alloy structural steel, tungsten-carbide hardfacing, technology MCAW - WC flux cored electrode in protective active gas.
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Development of abrasion-resistant concrete and testing methods
Procházka, David ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with concrete abrasion resistance against abrasion. The constructions of transport and water management structures are most stressed by the action of abrasion by means of travel of vehicles and flowing water. Abrasion reduces the durability of the structures. The prerequisites for achieving the best possible abrasion resistance are examined. Furthermore, test methods that are currently used worldwide. The experimental part deals with the influence of individual types of aggregates amphibolite (Želešice), fecal gravel sand (Žabčice) and basalt (Bílčice) on abrasion resistance. Furthermore, the dependence between the strength of the concrete and the hardness of the surface for abrasion resistance. Abrasion resistance testing was determined by concrete abrasion, abrasion resistance by the Böhm method and by water jet.
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Stabilization of the flooded sand pit near Hulín
Tomšej, Lukáš ; Svoboda, Ondřej (referee) ; Šlezingr, Miloslav (advisor)
The diploma thesis assesses the current state of the Hulín gravel and sand plant and pays attention to abrasions of severely damaged banks of the reservoir. With the help of the design of a suitable biotechnical stabilization, the receding of the shoreline in the section of interest will be prevented. The basis for the processing of appropriate bank stabilization proposals is the results achieved using a method of determining shore retreat. The individual developed variants of the bank remediation solution emphasize the use of vegetation support, especially suitable bank stands to ensure the stability of the banks and protection against abrasion.
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Návrh stabilizace abrazí porušených břehů - údolní nádrž Brno
Hašpica, Radek
This Bachelor thesis concentrates on proposal of stabilizations damaged shores abrasions, which are situated in valley dam Brno. The author focuses on concrete location Osada, as well as on concrete part of shore. In the beginning is processed covering message, processing general proposal of shores stabilization and after that technical report. There are stated hydrological calculations after that, description of own designs of the author for stabilization shores in given locality. For processed photodocumentation, maps and drawing outputs please find attached.
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Study the abrasion resistance of concrete
Kolková, Kristína ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis deals with the issues of concrete abrasion resistance and it consists of a theoretical research part and an experimental part. The types of abrasion affecting concrete construction and abrasion effect of flowing water-borne sand are described in the theoretical research part. A substantial part is dedicated to the impact of concrete properties and to each material of the concrete mixture on the abrasion resistance. The impact of addition of various types of fibers is inquired. The mixtures with the addition of 2 kg.m-3 and 4 kg.m-3 of basalt fibers and the addition of 1 kg.m-3 and 2 kg.m-3 of polypropylene fibers are designed in the experimental part. The mixtures are compared to a reference mixture without fibers. Density and consistency of fresh concrete settling at 5 minutes are determined in fresh condition. Density, compressive strength, tensile strength, watertight, concrete absorption and bending tensile strength are determined on hard concrete. The impact of the addition of fibers to the concrete abrasion resistance is inquired using the Bohm abrasion method and wheel abrasion method. A water jet is used as another method for testing abrasion resistance and for comparing the suitability of the used methods.
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Effect of toothpaste abrasiveness on friction and wear of dental fillings
Formánková, Pavla ; Čípek, Pavel (referee) ; Vrbka, Martin (advisor)
This bachelor thesis dealt with research, that links dental hygiene issues with tribology. The aim of the thesis was to analyze the effect of abrasive particles of toothpastes on friction and wear of dental fillings. The friction coefficient was evaluated in a tooth brushing simulation on an UMT TriboLab tribometer that lasted 260 minutes. The tribological system consisted of a toothbrush, a sample of composite material and a solution of artificial saliva with a selected toothpaste. Each paste was defined by an RDA value from 0 to 250, expressing the degree of abrasiveness therefore the ability of the toothpastes to wear the material. Wear was analysed on a Bruker Contour GT-X optical profilometer. From the measured values it was found that the influence of abrasive particles is significant in terms of wear of dental fillings. For both the friction coefficient and the material loss when measured only in the presence of artificial saliva, the resulting values were generally lower. However, the material loss in the toothpastes measurments did not increase linearly with the RDA value as expected. Literature studies and measurements have shown that this may be due to other factors affecting wear. Future research on these factors could lead to the selection of more gentle toothpastes in dentistry and thus prevent the increase in wear of dental fillings
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Stabilization of the flooded sand pit near Hulín
Tomšej, Lukáš ; Svoboda, Ondřej (referee) ; Šlezingr, Miloslav (advisor)
The diploma thesis assesses the current state of the Hulín gravel and sand plant and pays attention to abrasions of severely damaged banks of the reservoir. With the help of the design of a suitable biotechnical stabilization, the receding of the shoreline in the section of interest will be prevented. The basis for the processing of appropriate bank stabilization proposals is the results achieved using a method of determining shore retreat. The individual developed variants of the bank remediation solution emphasize the use of vegetation support, especially suitable bank stands to ensure the stability of the banks and protection against abrasion.
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Stabilization of the flooded sand pit near Hulín
Patková, Aneta ; Pelikán,, Petr (referee) ; Šlezingr, Miloslav (advisor)
The aim of this bachelor thesis is to assess the current state of the bank damaged by abrasion of the flooded gravel and sand pit in Hulín with the subsequent proposal of suitable biotechnical or biological stabilization and hydrological calculations to determine the prognosis of the prognosis retreat of the coast. As part of the field survey, photo documentation of abrasive log cabins caused by wind waves and water level fluctuations was taken. Part of the work is also the proposal of a total of six stabilization measures, the construction of which should prevent or slow down the effects of abrasion.
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Study on wear of material in contact with MR fluid
Žáček, Jiří ; Vimmr, Jan (referee) ; Kubík, Michal (advisor)
This paper is focused on MR dampers and its critical parts in term of damper`s durability, which seems to be a piston-rod seals, and it should find an ideal material combination of seal and MR fluid for increasing the damper`s life. The tests were conducted in modified pin-on-flat configuration, which was supposed to be more suitable for laboratory testing. There was tested and compared a suitable material for seals, like PTFE, NBR, SBR of polyurethanes. The article is also focused on MR fluids and its contribution to seal`s wear. The impact of particle concentration, wear of MR fluid and effect of modification of MR fluid was tested. It showed up, that the best material for seal is H-PU95FDA. The effect of particle concentration is negligible on seal`s wear, while effect of modification and wear of MR fluids are significantly higher.
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