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Mortar with alkali-activated matrix
Černá, Hana ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis addresses the issue of alkali-activated materials and their manufacturing components. In the theoretical part the description of such materials is provided and the requirements for source materials are defined. The theoretical part further addresses the resistance of alkali-activated materials and their lifespan - namely sulphate resistance, chloride resistance, acid resistance, frost resistance, porosity, carbonation, resistance, abrasion resistance and heat resistance. The experimental part of the thesis focuses on compounding four different mixtures of alkali-activated materials. In the loosened stage, the weight was measured. In the hardened stage the weight was measured as well as the tensile strength when bending, the strength under pressure applied, heat resistance, water and defrosting chemicals resistance and formation of cracks.
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Thorium in environment
Adam, Rostislav ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
All known isotopes of thorium are radioactive, 6 of them occur in nature decay chains. Thorium forms mainly cation Th4+ . Because thorium behaves like REE, Ce, Zr, Hf, Sc and U, it is a problem with thorium separation. There is requested leach thorium from ore for production of thorium. Monazite is mostly used for industrial production of Thorium. Electrolysis or chemical reduction are the most spread technologies for metal thorium production. For determination of thorium can be used many methods. Currently there is are usualy used radio-spectrometry or mass-spectrometry for determination of Thorium. Thorium occurs in small amounts in all parts of environment. Most of naturally occuring thorium are in the solid part of environment. Radioactive decay of thorium are using in geochronology. Thorium could be use in future as nuclear reactors fuel. Some other usage of thorium are catalyst in organic synthesis, Welsbach lamps or non-silicate glass. Thorium have also some chemical toxic efects for all organism, but more serious problem is its radioactivity. Final product of radioactive decay is lead. Non-stable products are radium, radon, bismuth, thalium and polonium. All products of radioactive decay have some specific chemical toxicity. 1
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Study utility properties of heat-reflective insulation for the buildings
Rauchfussová, Karolína ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
Presented work deals with the study progressive heat-reflecting foil thermal insulating materials and defines their thermal insulation properties. The work describes a transport mechanism of thermal energy in the structure of heat-reflecting materials, their physical properties, especially heat resistance, compared to the conventional thermal insulating materials available on Czech market. The main applications ways and installation methods of these materials (especially in low-energy and passive buildings) are also shown. The practical part is focused on asembling the measuring device HOT BOX in accordance with the valid standards, to determine the heat resistance of heat-reflecting materials. In next step the measurement of reflection of aluminum foils (an integral part of the structural arrangement heat-reflecting foil insulations) was performed.
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The Effect of Sawdust on the Refractoriness of Insulation Chamotte
Smékalová, Veronika ; Kotásek, Martin (referee) ; Sokolář, Radomír (advisor)
Lightweight refractory products have their place between refractory materials. Still the most common way of lightweighting is by using burnable components. This bachelor work includes the theoretical part, which deals with raw materials for lightweight fireclay, manufactory, and also testing lightweight refractory products. The second part of this work deals with foreign research and its results in this area. The practical part examines the influence of the types of sawdust (spruce or beech) on properties of lightweight refractory materials. The work focuses mainly on heat resistance, temperature usability, thermal conductivity, and density. These properties are evaluated with consideration to the ash which is created by burning sawdust.
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Determination of thermal properties of gloves by means of thermal manikin
Pidrová, Kateřina ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on determination of thermal properties of gloves by means of thermal manikin. The background research with relation to this topic together with derivation of the computational equations used for the following measurement are presented in the first part. The most significant part of this work is suggestion of procedure for measuring the heat resistance of gloves with thermal manikin based on procedure from ČSN EN 511. This methodics was verificated with 5 pairs of gloves together with analysing the uncertainties and testing the repeatability of this measurement. This work also contains the outline for all of the measured pairs with posibilities of their usage in specific situations and surrounding air temperatures. At the end of this work is mentioned brief summary of achieved results.
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Evaluating and modeling of fouling process in heat exchanger
Čirka, Martin ; Kilkovský, Bohuslav (referee) ; Jegla, Zdeněk (advisor)
This diploma thesis discusses fouling processes and mechanisms of industrial heat exchangers, with focus on shell side fouling of heat transfer area by flue gases, and eventually taking fouling into account, or more precisely its modeling and predicting by calculation. Thermal-hydraulic design of heat exchanger is focused mainly on shell side, as flue gases are dominant process medium in terms of fouling and heat transfer. Based on available operational data of evaluated industrial heat exchanger, specific process has been developed to determine by calculation, or more precisely predict change of fouling factor throughout operational period of heat exchanger. Usage and various options of this specific calculation technique are being discussed in conclusion, whether there is a potential to use this technique regarding more complex operational inputs or prediction of fouling process for different operational regime of heat exchanger.
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Sports complex
Touš, Jakub ; Pobořil, Lukáš (referee) ; Petříček, Tomáš (advisor)
The main focus of this thesis is to design the expansion and modernization of a sport complex "U Jezu" for a sport club TJ Roztoky. This thesis is consisted of a study for a territorial agreement. In this study, there are indicated a formation of two playing fields with the artificial surfaces, beach volleyball court proposing two building objects as a base for the entire complex, which consists of garages, storages and a main building. A more detailed design was created for the main building. As the supporting structure of the object, the transverse wall system completed with outdoor columns supporting the cantilevered portion of the ceiling tiles, which are mainly unidirectionally reinforced concrete floor slabs. The supporting structure is based on the strip foundations. The designed building object has two-above ground floors and a ground floor, which will be created by embedding the building object into the hill side. The ground floor is designed for the relaxation and the leisure purposes. Moreover, there is also a technological equipment necessary for the operation of the facility. On the first above ground floor, there are designed locker rooms for athletes, a club room with a kitchen and an accommodation unit for a manager of the complex. The second floor is for the accommodation. There are designed rooms with lounge and office of the president of the sport club. Part of the second floor consists of a terrace. For the roofing, a flat roof with a single-classic sequence of layers is designed. In this thesis, the static is partially solved. Furthermore, the object is evaluated in the terms of lighting, acoustic and thermal requirements as well as requirements for the fire safety of buildings.
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Lodging house for cyclists
Jirka, Petr ; Peterka, Tomáš (referee) ; Müller, Jan (advisor)
The subject of this thesis is a design of a newly built guesthouse on a bicycle path in the village Spálené Poříčí. The building is designed in a gently sloping terrain towards the west. The main entrance faces the south. It is an object without a basement and with two above ground floors. The structure of the building is a transverse wall system made of ceramic fittings. Other walls are also made of ceramic fittings. The entire building is based upon the stripe foundations and footings. Pension is covered in the part of the accommodation and in the restaurant part with a gable roof. For the restaurant, a terrace is designed on the west side of the building. In this thesis, static and building equipments are solved. The building is also evaluated in the terms of lighting, thermal, acoustic requirements and the fire safety of building is also solved.
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Determination of Vuppor admixture for the refractory light weighting bodies
Svobodová, Markéta ; Keršner, Štěpán (referee) ; Sokolář, Radomír (advisor)
Lightweight refractory products are materials used for the construction of certain parts of industrial furnaces, especially for iron, but also in other sectors where is operated with high temperatures. There are special requests on refractories. The theoretical part contains an overview of used raw materials, production and properties of lightweight refractory products and description of not burnable lightener - chemical additives VUPPOR I and information about previously conducted trials dealing with these topics. The practical part is divided into four parts, which are evaluated by tests which were performed on a refractory clay with chemical additive Vuppor I (samples are lightened and not lightened) - it was primarily a test of sensitivity to drying, density, compressive strength, thermal insulating properties, etc.
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Monitoring the Influence of ceramic bond on the properties of insulating refractory materials
Friček, Jakub ; Kovář,, Pavel (referee) ; Nevřivová, Lenka (advisor)
Thermal insulating refractories are an integral part of each thermal unit since they reduce its energy consumption. The current phenomenon of saving in both environmental and financial aspects reflects in searching for such possibilities to produce at lower manufacturing and material costs. One of the possible ways is to valorise waste materials. The theoretical part then deals with the division of refractory materials, classification of thermal insulation refractory materials and manufacturing technologies. The experiment is focused on the production of insulating refractory materials made from plastic dough with a possibility of using sawdust and materials made by pressing mixture moist, with a focus on coal bottom ash. Both of these technologies will be tested for the possibility of modification by using mixed clays and of increasing the strength by using clays with lower sintering temperature.
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