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Thermal degradation of hyaluronan
Šimáčková, Marcela ; David, Jan (referee) ; Chytil, Martin (advisor)
This diploma thesis investigated thermal stability and the degradation of hyaluronan (HA) in HA with a molecular mass of 90–130 kDa and in HA with a molecular mass of 1 500–1 750 kDa. The following methods were used for the research: rheology, SEC-MALLS, TGA and DSC. Low-molecular HA was subject to time dependency of degradation investigation, where it was dried at a temperature of 90 °C for a period of 30 minutes and 60 minutes prior to the preparation of the solutions itself. High-molecular HA was investigated not only from the point of view of time but from the point of view of temperature dependency of degradation as well. In the case of investigating the time dependency of degradation, high-molecular HA was dried at a temperature of 75 °C at a time range from 15 minutes to 120 minutes prior to the preparation of the solutions. During the preparation of the solutions for discovering the temperature dependency of degradation, the high-molecular HA was then dried for a period of 30 minutes at a temperature range from 60 °C to 90 °C. For low-molecular HA, thermal stability was proven. Therefore, there is no decrease in the molecular mass and the solutions did not demonstrate a significant decrease of viscosity. For high-molecular HA, thermal stability was not proven. Degradation due to the temperature of drying as well as the time of drying occurred, which was demonstrated by a significant decrease in molecular mass and viscosity of the solutions. While in the case of using a drying temperature of 60 °C, a decrease in the molecular mass occurred by approximately 5 %, the molecular mass decreased by approximately 20 % at a drying temperature of 90 °C compared to undried HA. Due to this reason, high-molecular HA was also further investigated by means of the TGA method, where the decrease of humidity of HA samples in relation to the drying temperature was observed. The DSC method was also used. The objective of the DSC method was to find out temperatures, at which evaporation of humidity contained in an HA sample in relation to its form (undried HA, dried HA and lyophilized HA) occurs. This method further finds out the heat necessary to evaporate humidity from an HA sample. To conclude this research, the results obtained for high-molecular HA were compared with the results of other drying processes – lyophilized proved to be a very gentle drying method because a decrease in the molecular mass for lyophilized HA compared with undried HA almost did not occur.
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The effects of vegetative roofs onto the thermal stability of a building object
Majsniar, Michal ; Moudrý, Ivan (referee) ; Vimrová,, Hana (referee) ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
Dissertation deals with thermal technical assessment songs vegetation roof with moisture, the more the influence of vegetation on the roof thermal stability of the structure. The aim of this work is to demonstrate the beneficial effect of vegetation roofs, specifically growing Formation of thermo-technical point of view on the favorable temperature conditions in the building. Such speech can be captured only if it is judged-temperature profile dynamically daily operation of real marginal climatic temperatures. Using a stationary or quasi-stationary boundary climatic temperatures which are usually used for the determination of the energy performance of buildings, said effect can not be collected. Demanding simulation calculation, which apply material properties - thermal conductivity, density and thermal capacity, but gives a realistic picture of the thermal processes in progress not only in the roof structure of the building, but also across the entire circuit construction of a building. During the preparation of the dissertation was assembled machine program that works with the energy flow between rooms in the building and the surrounding environment. Furthermore calculates temperature gain of residence of persons, internal lighting and sunlight. The values of the internal environment are calculated from surface temperature, relative humidity, air exchange and, of course, the indoor air temperature with hourly weather data. In constructing the program was included in the calculation of the solar radiation both on flat and on an inclined surface. The output of the energy value and temperature conditions in individual rooms, which include not only thermal insulation but also thermal storage properties of an object. Using experimental measurements were able to demonstrate that the calculated values closely correlate real thermal processes, so it can be demonstrated through the calculated results of the vegetation roof has a favorable effect on the thermal state espe
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Energy-efficient hotel building in Karviná
Segeďa, Petr ; Rubinová, Olga (referee) ; Počinková, Marcela (advisor)
The aim of the master’s thesis is to design an energy-efficient hotel in Karviná. In the first part, an architectural and structural solution was proposed. The building has three above-ground storeys. The structural system was designed as structural frame with beams and slabs, made of reinforced concrete. The material of external wall is aerated concrete blocks insulated with the ETICS with poly. The roof is flat. There are 40 thermal collectors and 69 photovoltaics panels. On the first floor, there are four guest rooms, a restaurant, a kitchen, a reception, toilets, a utility room, a mechanical room, and facilities for employees. The guest rooms are located on the second and third floor. HVAC was designed in the second part. Heating is provided by two heat pumps. The first heat pump provides domestic hot water in the winter, heating with radiators, for air handling unit heaters and cooling in the summer. The second heat pump is used only for floor heating in the winter. In the building are designed four air handling units for the kitchen, the restaurant and two for the guest rooms. Rainwater from the roof is collected in accumulation tank for flushing the toilets. In the third part, I evaluated the calculation of energy performance certificate in two softwares, namely Energie 2021 and DEKSOFT. The aim to find out, why the results are different in these softwares. The Drawings were done in ArchiCAD. The calculation part was made in Excel.
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Heat-moisture and Heat Storage Properties of Heavy Structures of Sloping Roofs
Pilný, Ondřej ; Ostrý, Milan (referee) ; Novotný,, Marek (referee) ; Kalousek, Lubor (advisor)
The heavy claddings of sloping roofs are increasingly being incorporated into the common constructions of family houses, apartment buildings and other civic amenities. Thanks to the increasing demands for energy savings in the form of ever-tightening values of heat transfer coefficients and other thermal engineering requirements, these designs are the answer to how to achieve the requirements more easily. Furthermore, they are able to influence the passive thermal stability of interiors and thus solve not only the issue of overheating of buildings, but also to achieve energy savings in the case of thermal stabilization of the interior throughout the year. However, if there is a lack of understanding of these different constructions for heat-moisture and heat storage behaviour, there is a risk of the opposite effect and a risk of deterioration of interior thermal stability. Therefore, it is necessary to better understand these structures in terms of behaviour and the impact that their use has on the building itself. Also, it is desirable to understand the effect of changes in their partial material properties and of the composition itself on the functioning of heat-moisture and heat storage properties of compositions that use these materials.
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Polyfunctional house
Kuklová, Jana ; Pilný, Ondřej (referee) ; Berková, Petra (advisor)
The main aim of the thesis is to design a new building of the mixed-use building in Brno. The building consists of two parts. One part consists of shops. The second part consists of offices and conference space. It is a building that has three floors above ground and one underground. In the basement there are a facilities and a garage. Shops are designed on the ground floor. There are offices on the second floor. Conference rooms are on the third floor. The building has a flat roof. The vertical load-bearing structures are designed from Porotherm ceramic blocks. In the core of the building, the vertical load bearing structures are designed as monolithic reinforced concrete walls. Columns are used in the building for the possibility of open space. The masonry of the basement consists of white bathtub. The floors are designed as folded from the Spiroll system. Internal non-load-bearing walls are designed from gypsum board with double cladding. The second part of the work deals with forced ventilation, cooling and central heating. In the third part of the project I deal with acoustics. The project was carried out in the Auotocad program. All constructions comply with valid standards and regulations.
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Flame retardant treated thermosets for composite materials used in transport industry
Novotný, Kamil ; Kučera, František (referee) ; Poláček, Petr (advisor)
First part of this bachelor‘s thesis contains a literature review, which describes basic mechanisms of flame retardancy, distribution of flame retardants into groups based on their composition and commercially available compounds. Experimental part studied the change of thermal stability and flammability of a thermoset resin with the adition of flame retardants. Change in mechanical properties of the resin was investigated as well. Epoxy resin was selected as a specimen of the resin group due to its excellent properties, which make it widely used in transportation industry. The main disadvantage of epoxy is its high flammability. The effect of two low cost, eco-friendly, easily applicable flame retardants was observed, namely expanded graphite and magnesium hydroxide. Materials were evaluated by a burning test, tensile test and thermogravimetric analysis. Overall, the additives caused a decrease in mechanical properties. Material with a combination of both compounds was found to be the least flammable, but had the worst mechanical properties.
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Civic amenities building
Baroň, Alexandr ; Pilný, Ondřej (referee) ; Berková, Petra (advisor)
The first part of this diploma thesis is to design an energy-efficient hotel with restaurant and car parking. The second part is also to create an assessment of the energy performance of the building and usage of energy from renewable sources. Hotel is designed with the idea of „smart buildings“ which means, that all the technological background is controlled by the main computer, which also harvests data to achieve a minimum energy use and financial demand and maximum comfort and safety at the same time by controlling the connected technology. By placing on a sloped terrain in the center of Brno, the basement floor can be used as car parking. The roof of this building is flat, green, with modifications for placing solar panels, whose design is part of this work. The third part of this diploma thesis is the spatial acoustics of the conference room on the first ground floor.
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Stability of soil organic matter and humic substances
Nováková, Šárka ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
This diploma thesis is focused on changes of stability in organic matter by extraction in different agents. Two soils of a different type and isolated humic acids were used for stability determination. Extraction agents were selected usually used for soil metal extraction, and a changes in the structure of the organic matter was observed. Samples were characterized using FTIR analysis and elemental analysis, the extracts were measured by UV-VIS spectroscopy, absorption ratios E2/E3, E4/E6 were discovered, dynamic light scattering were determined for particle size distributions. Next part of the thesis was the assessment of the change of thermal stability using thermogravimetric analysis and differential scanning calorimetry, degradation temperatures of the extracted samples were discovered and compared with the original samples.
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Tepelná stabilita pektinů
Vališová, Petra
Thesis on Thermal stability of pectins analyzes the physical properties of food hydrocolloids focusing on pectins. The theoretical part explains the general use of hydrocolloids in food with a detailed description of linear polysaccharide galacturonic acid. This part of the thesis pectins divides into groups according to various criteria, describes the mechanism of gel formation, explains the influence of various factors, and also shows the enzymatic reaction. The experimental part is focused on the physical parameters of selected types of pectins, depending on the time of warming and high temperature. The primary physical properties as viscosity, which was measured using a rotational viscometer and strength which was measured by a mechanical and digital penetrometer. This was measured thermal stability.
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