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Belt conveyor for transport of limestone
Kaderka, Zdeněk ; Škopán, Miroslav (referee) ; Malášek, Jiří (advisor)
This thesis is dealing with the design of the inclined belt conveyor for transport of crushed limestone. Thesis is specialized on the functional calculation, main dimensions of the conveyor, according to the valid standard ČSN ISO 4058 and design of the drum drive. Thesis includes assembly drawing of the conveyor, subassembly drawing of the welded support and subassembly drawing of through part of conveyor frame.
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Lime mortars with the addition of ground limestone
Žižlavský, Tomáš ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The thesis is focused on an effect of addition of ground limestone on properties of lime based mortars. Theoretical part of the thesis deals with diferenciation of plasters and their utilization, history of using limestone as an aggregate, its exploitation in the present and its impact on properties of lime based plasters, specially on strenghts. In the next part there's elaborated the carbonation reaction including the influence of external agents. Practical part of the thesis is focused on proving assumtions from theoretical part, particulary on the influence of ground limestone on the strenght properties of lime based plasters.
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Study of the influence of additions on the durability of aerated concrete
Halešová, Adéla ; Voves, Jiří (referee) ; Hubáček, Adam (advisor)
The aim of this work is to summarise and consider the possibilities of using admixtures and their influence on the durability of aerated concrete.This bachelor's thesis is based on research findings concerning aerated concrete. Furthermore, it deals with the study of inert and active additions. The experimental part is focused on testing trial samples with the addition of admixtures. It examines what is the rate of the possible chosen physically-mechanical features such as the rate of air density, the durability of surface against the effect of water and chemical defrosting substances and achieving the required strength.
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Possibilities of using different types of admixtures in shotcrete technology
Berčík, Martin ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
The Bachelor’s thesis is conceived in the form of research findings on current knowledge of inert and active ingredients and their effects on the shotcrete. It focuses mainly on the composition of individual ingredients, their function executing in the concrete mix and explains how they affect the selected physical and mechanical properties. The work enlightes the importance of using co-products from the industry production as an additive to concrete in terms of both ecological and partly economical.
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SCC with secondary raw materials
Ťažká, Lucia ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
Bachelor thesis is focused on the possibility of using secondary raw materials and their application to the production of SCC. Large part deals with impurities of type I and its application results mainly from abroad. Furthermore, this work examines the impact of different types of impurities on the resulting concrete durability in various aggressive environments. The practical part is focused on the use of chemically non-reactive additives of type I instead of the commonly used additives of type II which are used to replace part of cement and the resulting design and manufacture of low-strength SCC using appropriate additives.
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Modification of dry stuff with lime sludge
Švec, Jiří ; Kovářová, Alena (referee) ; Ptáček, Petr (advisor)
In modern point of view of waste management is desirable to effectively process the grates possible amount of wastes. Sediments from cleaning of mined lime stones contains a lot of clay components, but there is also indispensable share of soft calcite. Especially this can be use in following processing. After firing, where is necessary to set suitable temperature, arises a mixture of soft calcinated lime and remaining dehydrated mineral components. This calcinated mixture could partially replace used binders in dry stuffs.
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Preparation of PP composites by grafting using monomer treated filler
Kramerová, Nina ; Žídek, Jan (referee) ; Kučera, František (advisor)
Bachelor thesis is focused on preparation of composite materials with polypropylene matrix. The composites were prepared “in situ” with using Brabender mixer. Homogenization of matrix and filler and grafting of PP with anhydride of itaconic acid treated filler proceed together according to radical mechanism of polymerization. Luperox 101 [2,5-dimethyl-2,5-di(tertbutyl-peroxy)hexane] was used as an initiator of the reaction, the concentration of the initiator was 0.5 wt %, processing temperature 210 °C, 30 rpm. PP-g-IA is a compatibilizer between the matrix and the filler. Glass fibers, calcite and two types of ground wood pulp were used as filler. Two analytical methods were chosen to analyze the efficiency of grafting, acid-base titration and infrared spectroscopy. Assigned conversion of monomer was from 42 to 87 % for various fillers.
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Cyanobacteria in the splash zone of the Veruda and Ugljan islands, Croatia
VONDRÁŠKOVÁ, Alžběta
Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed on 16 localities both in horizontal and vertical directions. In 336 samples 42 cyanobacterial species, 1 green alga, and 1 red alga were found. On both islands Hyella spp. and Gloeocapsopsis crepidinum dominated. Solentia spp., Kyrtuthrix dalmatica, and Mastigocoleus testarum were also found frequently. According to statistical analyses 3 horizontal parts of the splash zone were shown to host different cyanobacterial communities. In the horizontal direction there were no statistical differences among sampling points; however, for uncovering the whole cyanobacterial diversity more samples from various distances are necessary. The species diversity and distribution were not dependent on the orientation of the locality toward cardinal points.
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Cyanobacteria in the splash zone of the Veruda and Ugljan islands, Croatia
VONDRÁŠKOVÁ, Alžběta
Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed on 16 localities both in horizontal and vertical directions. In 336 samples 42 cyanobacterial species, 1 green alga, and 1 red alga were found. On both islands Hyella spp. and Gloeocapsopsis crepidinum dominated. Solentia spp., Kyrtuthrix dalmatica, and Mastigocoleus testarum were also found frequently. According to statistical analyses 3 horizontal parts of the splash zone were shown to host different cyanobacterial communities. In the horizontal direction there were no statistical differences among sampling points; however, for uncovering the whole cyanobacterial diversity more samples from various distances are necessary. The species diversity and distribution were not dependent on the orientation of the locality toward cardinal points.
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Aerophytic cyanobacteria from limestone quarry Malá Amerika
KOČVARA, Luboš
The presented work was aimed on discovery of diversity of aerophytic cyanobacterial vegetation of Malá Amerika limestone quarry located in Český kras Protected Landscape Area, Czech Republic. It was found and determinated 20 morphotypes of cyanobacteria. Moreover, putative effects of light, water availability and a distance from water level on species diversity have been studied. It has been shown that the limiting factor on this locality is humidity, not light.
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