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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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The optimalization of clay building components
Melichar, Jindřich ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
Clay building components are nowadays one of the most used building materials in the world. Except easy availability and processability clay building components have also heat storage function. This master´s thesis will be considering possibilities of improving thermal and mechanic properties of these materils by additing suitable reinforcements.
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Detached Family Residence
Mikuš, Martin ; Vávra, Petr (referee) ; Vajkay, František (advisor)
The subject of this work is the design of a detached family house in area Nove Domky near Jihlava in which natural construction materials were used. Instead of concrete or bricks, this building is designed with materials such as straw, rock, timber, clay, hemp or sheep's wool. Furthermore, the work deals with methods of plumbing, electrical installations and heating. The possible utilization of natural energy resources or ecological processing of waste were also taken into account. The conclusion contains the financial comparison with a building where traditional and industrially produced materials are used.
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Cost of construction of houses of alternative building materials
Lošáková, Jana ; Gilar, Ing Přemysl (referee) ; Výskala, Miloslav (advisor)
This bachelor`s thesis deals with cost of construction of houses from natural building materials. There are defined natural building materials. There are also introduced their properties and specific options of use of individual materials. Prices and properties of materials are compared with prices and properties of industrially produced materials. This thesis is supposed to show, that there is no need to be affraid of using natural building materials. These materials are fully comparable, ether by price and its features, with materials commonly used.
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Rehabilitation technology of embankment dams by using suitable types of waste
Michalčíková, Magdaléna ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
The subject of this work is to find an optimal technology for repairing existing embankment dams with emphasis on simplicity and ecological scalability. Next, secondary energy and waste materials will be evaluated as a partial replacement of a quality montmorillonitic clay. The aim of this will be to maximize the use of these waste materials. In the end a selection of materials for the locality will be made. The use of appropriate types of waste for repairs of embankment dams with clay based grouting compound technology has a great potential, especially with those dams that are not fulfilling their function due to their age.
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An experimental study of initial succession on different substrata: analysis of changes in plant species cover and some soil biological parameters and their relationships
KRESÁČ, Martin
A four year experimental study of initial stages of succession on different substrata (sand, peat and gray clay overburden from brown coal mining) was carried out. The substrata were transplanted into two different landscape types in the Czech Republic. Control plots were filled with autochthonous topsoil treated with high temperature vapor. Plots with un-treated autochthonous topsoil were also established. Plant species cover and several soil-biological parameters (soil microbial biomass, basal soil respiration, exchangeable pH(KCl), organic-C extractable by potassium sulfate solution, and nitrate-N content) were measured once a year. Obtained data were mainly processed by unimodal (plant cover data) and liner (soil-biological data) ordination methods. Biological species traits (life span, seed dispersal vector, seed bank type, ecological strategy type following Grime, life form following Raunkiaer) were used to characterize early stages of plant succession. Vegetation and measured soil-biological parameters, except pH(KCl), were significantly changing during four growing seasons. Variance partitioning analysis based on plant species cover data indicated the landscape type to be the main governing factor and physico-chemical characteristics of substrate to be less important during the studied initial stages of succession. The same analysis based on soil-biological parameters showed the reverse result. Great variability of plant species ecological traits was noticed during four growing seasons. The earliest plant colonizers were mainly ruderal, anemochorous terophytes with persistent seed bank. The number of species with C-strategy type increased during the study. The relationship between the average plant species cover and measured soil-biological parameters was also examined during the experimental study of early succession. Direct and indirect ordination revealed the average sum of plant species cover to be weakly positively correlated with soil microbial biomass, basal soil respiration, nitrate-N, potassium sulfate extractable organic-C, metabolic quocient (qCO2) and negatively correlated to exchangeable pH(KCl). The relationship was significant only in the case of microbial biomass and potassium sulfate extractable organic-C. More detailed studies of the relationship between aboveground plant species biomass and soil microbial communities in initial stages of succession are required. Comparability of presented study is limited because not many experimental investigations of similar kind have been presented until now.
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Může průchod střevem žížal ovlivnit strukturu jílových minerálů: předběžné výsledky
Hušák, M. ; Frouz, Jan ; Had, J.
The effect of gut passage by three earthworm species (.i.Lumbricus rubellus, Dendrobaena octaedra, Dendrodrilus rubidus./i.) on the structure of ingested clay minerals was studied using X ray powder diffractometery. No differences were found in the peak's positions in diffraction spectra of clay spoil and clay in earthworm casts, indicating no changes in clay lamella inter-spacing. Differences were found in the peak's sizes, which seem to be caused by changes in preferential orientation of clay minerals during gut passage.
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Sensitivity framework-a tool for the constitutive modelling of double-porosity materials
Mašín, David
An original approach to constitutive modelling of double-porosity materials is presented in the paper. The approach is based on the parallel in the mechanical behaviour of these materials and sensitive clays. After summary of the framework for the behaviour of natural clays (Cotecchia a Chandler, 2000) a new simple constitutive model based on the Modified Cam-Clay model, which allows for modelling of the degradation of the intergranular porosity, is proposed. Finally, its application to the double-porosity materials is discussed.
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