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Innovative wood-based materials
Buriánek, Vlastimil ; Brožovský, Jiří (referee) ; Vaněrek, Jan (advisor)
This bachelor’s thesis deals with the issue of optimizing the modification process for plywood boards. Optimization consists mainly in evaluating different densification methods with different parameters of plasticization and stabilization. Psychical parameters (bulk density, swelling, water absorption) and strength parameters (bending strength, modulus of elasticity) of modified plates were chosen for the evaluation parameters. The practical part involved the verification of two thickening treatments on birch plywood.
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Monitoring of the wheat quality for food production
Slavíčková, Radka ; Hýsková, Eva (referee) ; Omelková, Jiřina (advisor)
The aim of this study was to monitor the quality of wheat Triticum aestivum, imported into the laboratory MORAGRO after harvest by eight different suppliers, and to evaluate the main quality parameters decisive for the final use of cereal crops. The introduction of the theoretical part was devoted to understanding commercial and agricultural importance of wheat and description of morphological and physiological characteristics of wheat grain. The core of the theoretical part has been focused on the description and explanation of physical and chemical properties of the wheat grain, which largely affect the final product quality of wheat. External factors affecting final quality and yields of wheat were also commented. The experimental part was based on measurements of main quality parameters of wheat (moisture content, bulk density, falling number, amount of gluten and the wheat proteins, sedimentation value and content of additives and impurities). In most cases, measurements were carried out using automated instruments. The quality of wheat was determined based on the obtained results, which allows deciding, whether it is appropriating for food production.
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Structural Properties of Ultralight Concrete and its Optimal Application in Structures
Kadlec, Jaroslav ; Bílek,, Vlastimil (referee) ; Adámek, Jiří (referee) ; Terzijski, Ivailo (advisor)
This doctoral thesis deals with design of three variants of ultra lightweight concrete (ULC) and their mechanical properties. The ULC usually has the dry density of 900-1200 kg/m3 and it is possible to use it for load bearing structures. Low density of ULC is achieved by replacing heavy aggregate for lightweight aggregate. The lightweight aggregate is known under the trade name Liapor in the Czech Republic. To achieve density below 1000 kg/m3, an aeration of the paste has to be done. An exchange of heavy aggregate for lightweight aggregate results in a very fragile behavior of ULC. A great attention is paid to bond strength between concrete and reinforcing steel in the thesis. In addition to the standard test of bond strength testing by pull-out, a modified pull-out test is designed, which includes the effect of minimum reinforcement cover. The mentioned test more precisely simulates a real behaviour of the structure exposed to bending moment. The doctoral thesis tries to point out on different parameters between measured data and the applicable standard for the design of load-bearing structures.
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Material properties research for use in high-temperature solar thermal storage tank
Šot, František ; Vala, Jiří (referee) ; TROJAN,, Karel (referee) ; Steuer,, Radek (referee) ; Šťastník, Stanislav (advisor)
The use of thermal storage energy, using phase change materials appears to be an effective way to store thermal energy storage with the benefits of the high amount of energy while maintaining isothermal nature of the process. PCM methods are used in latent thermal storage systems for heat pumps, as well as in solar engineering or for temperature control in spacecraft. The past decade has extended these principles for cooling and heating in the building. There are a number of PCM systems, which operate over a wide temperature range, are used in various applications. This document includes a brief overview of the development and analysis of available thermal storage working mainly on the principle of PCM.
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Optimization of Working Mass Composition for Dense Silica Bricks Production.
Maňák, Jan ; Lang,, Karel (referee) ; Nevřivová, Lenka (advisor)
A silica bricks is a refractory material which is used mainly in coke industry, glass industry and metallurgy. This material constitute of the quartz modifications. Compact silica is an irreplaceable part of the coke battery and its compactness and robustness is important for quality and long endurance. Very important for large compactness is a grain curve of work matter. This thesis deals with influence of different grain of work matter.
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Ultralight concrete with high utility properties
Popelková, Adéla ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.
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