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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Struktura, vývoj a funkce mikrobiálních společenstev v odumřelém dřevě / Assembly, successional development and functioning of microbial communities in deadwood

Bernardová, Natálie January 2020 (has links)
Dead wood is one of the most important reservoirs associated with forest ecosystems. In natural forests, its volume is counted in hundreds of m3 ha-1 , whereas it reaches only tens of m3 ha-1 in productive commercial forests. In contrast to soil and plant litter, deadwood is unevenly distributed on the forest floor. The specific physicochemical properties such as high content of recalcitrant polymers, low nitrogen level and impermeability negatively affect the rate of decomposition especially in the initial stages of wood deconstruction. The deadwood decomposition is very slow in comparisons with other substrates, it accumulates and thus it represents the important reservoir of nutrients. This thesis is focused on the structure, development and function of microbial (fungal) community in decomposing deadwood in unmanaged forest. Functional screening of fungi isolated from fruit bodies collected from coarse deadwood was set aside. Physico-chemical properties of deadwood including pH, carbon and nitrogen content and microbial biomass were estimated for four wood decomposition stages and three different tree species. New generation sequencing (Illumina MiSeq platform) was applied for fungal community structure analysis based on ITS2 fragment. Fungal functional screening was based on physico-chemical...
102

Boj proti únikům v oblasti nepřímých daní / Fight against evasion in indirect taxation

Havránek, Štěpán January 2013 (has links)
Thesis is focused on fight against indirect tax evasion. This topic was selected because it is a current issue. This is evidenced by media coverage regarding revealed tax evasion schemes; total estimated volume of tax evaded and increased activity of legislator in this field. The thesis is divided into three parts. In first part, I start with a general description of indirect taxes. I subsequently proceed with description of individual indirect taxes in the Czech Republic - value added tax, excise tax, and energy tax - and a brief summary of their evolution, main principles of functioning and their sources of law, both Czech and European. In second part, I tackle the problem of tax optimization, in particular the difference between legal and illegal methods of lowering ones tax. For this purpose, I go into more detail in explaining differences between tax planning, tax avoidance and tax evasion. I also draw attention to problems related to distinguishing these categories and to how these are interpreted differently by tax authorities in Anglo-Saxon and Continental area. After establishing theoretical background, I proceed by describing particular methods of evading tax, focusing mainly at illegal imports and carousel fraud, which, according to the Ministry of Finance, deprives Czech Republic of CZK 15...
103

Využití výživových suplementů v jednotlivých sportovních odvětvích / Use of Nutritional Supplements in Individual Sport Sectors

Weiser, Martin January 2015 (has links)
The aim of the diploma thesis was to determine, which nutritional supplements are selected by athletes of strength and endurance sports branches and what is the reason for their option. The theoretical part characterizes the 8 selected sports sector from point of view of the sport performance structure. There is also mentioned the issue of nutritional supplements, their division, legislation or general recommendations for the use in sport. The last chapter deals with the requirements for the use of nutritional supplements in different periods with respect to the branche of sport. Research part has specifically determined the nutritional strategy for athletes in the field of mentioned food supplements at strength and endurance-oriented sports disciplines by using the questionnaire. The research is supported by an interview with an expert nutritionist and sports through collaboration with the staff of the Centre for Sports of the Ministry of Interior
104

Vývoj kompozitů na bázi anorganických pojiv určených pro extrémní aplikace / The development of composites based on inorganic binders designed for the extreme applications

Janoušek, Petr January 2013 (has links)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
105

Vývoj požárně odolných správkových malt s jemnozrnným plnivem / The development of fire-resistant repair mortars with fine-grained filler

Záruba, Jiří January 2015 (has links)
The diploma thesis is focused on fire-resistant repair mortar with fine-grained filler. The aim of this work is the research and development of fine-grained Mortars resistant to high temperatures, which are characteristic at the beginning of the fire. The theoretical knowledge with subsequently realized laboratory verification was used. At-tention was paid to the masses based on the mixed binder comprising cement and blast furnace slag, respectively. high-temperature ash. Cellulose fibres were used as the dis-persed reinforcement. Two kinds of aggregate were assessed - fly ash agloporit and am-phibolite incl. combinations thereof. Laboratory tests were carried out via determination of basic material properties (density, strength, consistency, dimensional changes etc.) after exposure to extreme temperatures. A substantial part of the research was also study of different cooling conditions - slow and fast (water and air). Selected formulations were subjected to temperatures up to 1200 ° C. In the conclusion is selected several recipes that have been found to be optimal for continuing research on the basis of the results and findings.
106

Trvanlivost sanačních hmot pro železobetonové konstrukce s vyšší odolnosti proti požáru / Durability of repair materials with higher fire resistance for concrete structures

Počekajlo, Václav January 2015 (has links)
This dissertation deals with the study of durability and degradation repair mortars for reinforced concrete structures. In its theoretical part, there are the research findings on the behavior of repair mortars exposed to corrosive environments with different exposure time and selected high temperatures. Processes occurring in repair mortars during their loading at high temperatures or when exposed to chemically aggressive environments are described, We can find recipes designed for cementitious binder based with a specific replacement using slag or fly ash in its practical part. The object of the research was to determine the durability of the proposed repair mortars, and determine their suitability for use on concrete structures, which may be exposed to a synergistic effect of chemically aggressive environments with high temperatures simulating fire.
107

Vliv rozptýlené výztuže na průběh zrání polymercementových hmot / Dispersed reinforcement influence on the maturation of polymercement materials

Zaťko, Petr January 2017 (has links)
The diploma thesis is focused on polymercement materials with dispersed reinforcement. The aim of this work is development of suitable polymercement mixture and monitoring of the impact of dispersed reinforcement on the course of maturation of these materials and physico-mechanical properties. The effect of high temperatures on the properties of the mortar is also examined. Emphasis is placed on the use of alternative resources and byproducts. Mixed binder of cement and slag and admixture of microsilica was used. Recycled cellulose was used as dispersed reinforcement and was compared with commercial polypropylene fibers.
108

Quantitative Imaging in Scanning Electron Microscope / Quantitative Imaging in Scanning Electron Microscope

Skoupý, Radim January 2020 (has links)
Tato práce se zabývá možnostmi kvantitativního zobrazování ve skenovacím (transmisním) elektronovém mikroskopu (S|T|EM) společně s jejich korelativní aplikací. Práce začíná popisem metody kvantitativního STEM (qSTEM), kde lze stanovenou lokální tloušťku vzorku dát do spojitosti s ozářenou dávkou, a vytvořit tak studii úbytku hmoty. Tato metoda byla použita při studiu ultratenkých řezů zalévací epoxidové pryskyřice za různých podmínek (stáří, teplota, kontrastování, čištění pomocí plazmy, pokrytí uhlíkem, proud ve svazku). V rámci této části jsou diskutovány a demonstrovány možnosti kalibračního procesu detektoru, nezbytné pozadí Monte Carlo simulací elektronového rozptylu a dosažitelná přesnost metody. Metoda je pak rozšířena pro použití detektoru zpětně odražených elektronů (BSE), kde byla postulována, vyvinuta a testována nová kalibrační technika založená na odrazu primárního svazku na elektronovém zrcadle. Testovací vzorky byly různě tenké vrstvy v tloušťkách mezi 1 až 25 nm. Použití detektoru BSE přináší možnost měřit tloušťku nejen elektronově průhledných vzorků jako v případě qSTEM, ale také tenkých vrstev na substrátech - qBSE. Obě výše uvedené metody (qSTEM a qBSE) jsou založeny na intenzitě zaznamenaného obrazu, a to přináší komplikaci, protože vyžadují správnou kalibraci detektoru, kde jen malý posun úrovně základního signálu způsobí významnou změnu výsledků. Tato nedostatečnost byla překonána v případě qSTEM použitím nejpravděpodobnějšího úhlu rozptylu (zachyceného pixelovaným STEM detektorem), namísto integrální intenzity obrazu zachycené prstencovým segmentem detektoru STEM. Výhodou této metody je její použitelnost i na data, která nebyla předem zamýšlena pro využití qSTEM, protože pro aplikaci metody nejsou potřeba žádné zvláštní předchozí kroky. Nevýhodou je omezený rozsah detekovatelných tlouštěk vzorku způsobený absencí píku v závislosti signálu na úhlu rozptylu. Obecně platí, že oblast s malou tloušťkou je neměřitelná stejně tak jako tloušťka příliš silná (použitelný rozsah je pro latex 185 - 1 000 nm; rozsah je daný geometrií detekce a velikostí pixelů). Navíc jsou v práci prezentovány korelativní aplikace konvenčních a komerčně dostupných kvantitativních technik katodoluminiscence (CL) a rentgenové energiově disperzní spektroskopie (EDX) spolu s vysokorozlišovacími obrazy vytvořenými pomocí sekundárních a prošlých elektronů.
109

Rozklad černé, technika nedůsledného překládání Světla / The Breaking Down of Black, the Technique of Inconsistent Transfer of Light

Trnková, Barbora Unknown Date (has links)
Im interested in the topic of praying machine, because I want to analyze aspects of photography and its functions. It's known, that the reality is manipulated by photography. Bud we can also say, that the relationship between reality and photography is neutral in fact, that the manipulation is made by our interpretation of photography. The change of the reality can be realized just in the dialog between photography and reality. Can it be, that the mechanization change into the will? Does it prays praying mill or the buddhistic monk, who rotates the mill? When he believes into it, is it enough? Or is it enough if believes who watch the monk with his mill? ... The computers from he place A are "praying" the prayers from the place B. With Tomáš Javůrek we collaborated with Vladimír Veselý and Radek Lát to create the Game for re-articulation our reality on the base of the revision of our faith.

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