|
|
Suitability of vitrified lignite bottom ash for composite cements.
Bayer, Petr ; Krátký, Josef (oponent) ; Wolter, Albrecht (vedoucí práce)
The present master’s thesis seeks to develop a better understanding of using vitrified lignite bottom ash as a clinker substitute in composite cements. The influence of added vitrified bottom ash, as well as its fineness, alkaline solutions and its concentration was investigated. In composite cements prepared as specified in DIN EN 197 - 1, the clinker was replaced by 30 % of the vitrified bottom ash. In particular, the composite cements with vitrified bottom ash of fineness 5549 cm2/g and 8397 cm2/g were prepared. Furthermore, in order to stimulate the pozzolanic and/or geopolymeric reaction of the vitrified bottom ash, alkaline solutions of hydroxides and sulphates in two different concentrations were added. Mechanical properties of the prepared samples were characterized by mechanical strength testing on prisms with a proportion of 40×40×160 mm as specified in DIN EN 196 - 1. The non-destructive measurement of dynamic E-modulus and destructive testing on compressive and flexural strength were conducted. Moreover, particle size distribution and chemical analysis of input materials were performed by means of laser granulometry and X ray fluorescence, respectively. The hardened composites were investigated on phase composition and microstructure using X-ray diffraction and scanning electron microscopy after 2 and 28 days of hydration. Finally, the results showed that the mechanical properties are independent on the added amount of alkaline concentration or fineness of grounded bottom ash. However, the noticeable lower mechanical strengths were observed for samples with hydroxides activation likely due to the early silicate hydrogel formation. The strengths for samples with sulphate activation did not reach the strength of the reference mortar.
|
|
|
Volumetric Method for the Determining kg CO2 eq. and Energy Requirements for the Production of Power Tools at an Early Stage of Product Design
Sovják, Richard ; Sobotová,, Lydia (oponent) ; Grall, Günter (oponent) ; Křenek, Ladislav (vedoucí práce)
Emissions of kg CO2 eq. occur at different stages of the product life cycle and have a significant impact on global warming. The method used to assess these negative impacts is Life Cycle Assessment (LCA), which enables the determination of the carbon footprint, energy requirements of materials production, manufacturing processes, transport, use, and end of life (EoL). These analyses are time-consuming, costly to train, and require mass and material characterisation of products. The proposed VEME (Volumetric Evaluating Method of Ecodesign) method uses the volumetric properties of the product and its structural and material compositions. To achieve the objective, 134 power tools (manufactured from 1989 to 2018) were analysed with the inclusion of 10 types of categories based on the type of tool. 3D scanning was used to determine the volume of the product followed by material analysis and then the Oil Point Method (OPM), which is based on LCA. Tools were evaluated in three possible EoL variants (Landfilling, Combustion, and Recycling 90%). From the data obtained, a Monte Carlo simulation was performed for each tool sample of n = 1,000 with 95% confidence. Equations were established to determine the energy requirements for tool production, emissions of kg CO2 eq. (for 11 world countries), packaging and transport data. With 90% recycling, energy savings of up to 32.4% are possible compared to landfill. Of the 134 samples, 9.7% were recycled, where recycling was up to 6.2% more energy intensive than landfilling. This is due to the high energy requirements of the recycling materials. The new method will find applications in product design in industrial design, but also in the areas of the economic evaluation of production method and location. It can also be used to extend the energy labelling of products to include the energy intensity of production, transport, and packaging.
|
|
|
Daňové zatížení vozového parku vybraného podnikatelského subjektu
Dostal, Šimon
Bakalářská práce se zabývá roční silniční daní s environmentálními aspekty a jejím vlivem na vozový park vybraného podnikatelského subjektu. Teoretická část práce se zaměřuje na základní typy daní uvalené na silniční dopravu, teoretický rámec zdanění s environmentálními aspekty a v neposlední řadě analyzuje silniční daň v České republice a ve vybraných státech Evropské unie. Získané poznatky jsou uplatněny ve vlastní části práce při návrhu úpravy konstrukce silniční daně, která zohledňuje složku emisí CO2. Navrhnutá úprava je následně aplikována na vozový park podnikatelského subjektu s cílem kvantifikovat její dopady.
|
|
|
Suitability of vitrified lignite bottom ash for composite cements.
Bayer, Petr ; Krátký, Josef (oponent) ; Wolter, Albrecht (vedoucí práce)
The present master’s thesis seeks to develop a better understanding of using vitrified lignite bottom ash as a clinker substitute in composite cements. The influence of added vitrified bottom ash, as well as its fineness, alkaline solutions and its concentration was investigated. In composite cements prepared as specified in DIN EN 197 - 1, the clinker was replaced by 30 % of the vitrified bottom ash. In particular, the composite cements with vitrified bottom ash of fineness 5549 cm2/g and 8397 cm2/g were prepared. Furthermore, in order to stimulate the pozzolanic and/or geopolymeric reaction of the vitrified bottom ash, alkaline solutions of hydroxides and sulphates in two different concentrations were added. Mechanical properties of the prepared samples were characterized by mechanical strength testing on prisms with a proportion of 40×40×160 mm as specified in DIN EN 196 - 1. The non-destructive measurement of dynamic E-modulus and destructive testing on compressive and flexural strength were conducted. Moreover, particle size distribution and chemical analysis of input materials were performed by means of laser granulometry and X ray fluorescence, respectively. The hardened composites were investigated on phase composition and microstructure using X-ray diffraction and scanning electron microscopy after 2 and 28 days of hydration. Finally, the results showed that the mechanical properties are independent on the added amount of alkaline concentration or fineness of grounded bottom ash. However, the noticeable lower mechanical strengths were observed for samples with hydroxides activation likely due to the early silicate hydrogel formation. The strengths for samples with sulphate activation did not reach the strength of the reference mortar.
|
host ::
RSS.