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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.
11

Nové modifikované 7-deazapurinové báze a nukleosidy / New modified 7-deazapurine bases and nucleosides

Krömer, Matouš January 2015 (has links)
The three ways of synthesis of 5'-deoxy and 5'deoxy-5'-fluoromodified nucleosides derived from known cytostatic compounds was designed. Two routes were successfully developed and target substances were prepared. Third one was unsuccessful due to difficulties with deprotection of the key intermediate.
12

Aktivace sponzoringu u partnerů Českého atletického svazu / Sport sponsorship activation of partners of Czech Athletic Federation

Kuklík, Jan January 2021 (has links)
Title: Sponsorship activation of partners of Czech Athletic Federation Objectives: The aim of thesis is to create proposals for activating sponsorship for intentionally selected entities in connection with the Czech Athletic Federation on the basis of their own observations, case studies and in- depth interviews. The secondary goal is to evaluate the profile of companies in the role of sponsors and to determine the proposal for activations as a new discipline. Methods: Qualitative research based on in-depth interviews with representatives of selected companies, a case study and analysis of secondary data from documents dealing with athletics were used to determine specific activation proposals. Results: The results obtained from the research and the analysis of the profile of the Czech Athletic Federation and selected companies were used to determine specific proposals for activations for individual companies with involvement in Czech sports practice. Keywords: athletics, marketing communication, new media, sponsorship activation
13

Vliv typu aktivátoru na reologii a povrchovou chemii alkalicky aktivované strusky / Effect of activator nature on rheology and surface chemistry of alkali-activated slag

Russkykh, Kostyantyn January 2021 (has links)
V této závěrečné práci bylo popsáno časné reologické chování alkalicky aktivované strusky, anorganického materiálu, který vzniká aktivací mleté granulované vysokopecní strusky alkalickým roztokem. Vliv typu aktivačního roztoku (hydroxidů, křemičitanů a uhličitanů) a jeho koncentrace na časné reologické parametry byl zkoumán pomocí amplitudových oscilačních měření. Bylo pozorováno, že typ aktivátoru je hlavním faktorem ovlivňujícím reologické chování alkalicky aktivované strusky. Dále bylo pozorováno, že aktivátory na bázi draslíku vedou ke slabší struktuře (nižší mez kluzu, mez toku a nižší hodnoty viskoelastických modulů) oproti použití aktivátorů na bázi sodíku. To lze vysvětlit rozdíly ve velikosti alkalických iontů. Na rozdíl od ostatních aktivátorů křemičitany způsobovaly zvýšení ztrátového faktoru, přičemž vykazovaly spíše kapalné chování. Z výsledků vyplynulo, že většina aktivátorů má tzv. kritickou hodnotu koncentrace, po jejímž dosažení mají reologické vlastnosti vzorků tendenci se měnit s rostoucí koncentrací. Získané výsledky korelovaly s výstupy zeta potenciálu.
14

Funkce superplastifikátorů ve směsích alkalicky aktivovaných aluminosilikátů / Role of superplastisizers in alkali activated aluminate silicate mixtures

Habrdová, Eva January 2008 (has links)
Preparation of geopolymers with main components of slug and metakaolin. After being alcali activated the raw materials are complemented by superplasticizers of different kind and concentracion.
15

Příprava historických geopolymerů / Preparation of hystorical geopolymers

Šrámková, Eva January 2008 (has links)
Diploma thesis studies historical bonding agents on the base of geopolymers. The aim of the thesis is to find a proper material composition, especially made of natural clay materials (kaolinite, bentinite) and their modifications (metakaoline). These bonding agents have to have a suitable type of an activator that guarantees good bonding properties. Therefore testing of various kinds of alkaline activating ingredients on the same mineral composition was done. Except of usual hydroxides and a water glass, ancient natrons (mixtures of alkaline carbonate with addition of appropriate chlorides) and a lime mash were used as the activators. From the above mentioned mixtures, series of samples (columns 20 x 20 x 100 mm) stored at the laboratory temperature were prepared. In the prepared mashes, their workableness and moulding were investigated. In the developed samples, their surface appearance was observed together with a number of efflorescence and its types. An indivisible part of the research was formed by determination of mechanical properties of the experimental columns such as a compressive strength and a tensile strength in bending. Furthermore, phase composition of the samples and its changes with a temperature increase were investigated. For these tests, XRD and TG – DTA methods were used. A multi-seat isoperbolic calorimeter was used to study hydratation that was also the important part of the general evaluation of designed mixtures.
16

Příprava a vlastnosti ryzích geopolymerů / Preparation and properties of authentic geopolymers

Bartoňová, Pavla January 2009 (has links)
Evaluation of physical and chemical properties of geopolymer composites based on alkali aktivated metakaoline and silicate oxide.
17

Změny aktivity a obsahu enzymu Rubisco v listech špenátu v průběhu dne / Diurnal changes of Rubisco activity and its content in spinach leaves

Riegerová, Jana January 2010 (has links)
The graduation theses theme was to determinate changes of initial activity, total activity and Rubisco enzyme content in spinach leaves. Ascertained activities and Rubisco enzyme content were determined from extracts of spinach leaves, which were collected during two distinctively climatic different days. Both activities were determined by spectrometric method and content of enzyme Rubisco by SDS-PAGE method. The findings were compared with findings determined in earlier done works.
18

Příprava geopolymerních pojiv pro inhibici toxických prvků / Preparation of geopolymeric binders for toxic metals inhibition

Jevická, Lucie January 2011 (has links)
This thesis deals with preparation of geopolymeric binders for inhibition of toxic elements, especially arsenic. It studies influence of content progress of different phases in prepared binders on leachability of As during the setting. The aim of this study is to determine the type of inhibition or the cause of leachability of As in prepared binders respectively. Fly ash from high-temperature coal combustion, slag, cement kiln dust and sodium hydroxide solution were used for experimental works. FT-IR, TG-DTA, XRD analyses after different hydration times were used. The leachates were analyzed by ICP-MS. Calorimetric measurements of tested mixtures fresh pastes were implemented to learn about setting process. Hardened binder specimens were tested for bending and compressive strength.
19

Vztah parametrů přípravy belitického cementu a jeho hydraulických vlastností / Relation between Preparation Parameters of Belite Cement and its Hydraulic Properties

Staněk, Theodor January 2009 (has links)
The dissertation thesis is devoted to the study of belite clinkers and to the possibilities of the increase in their hydraulic activity. The mechanism and the kinetics of belite clinker formation were studied together with the relation of the velocity of these processes and the hydraulic activity of clinker. The influence of various parameters (degree of lime saturation, duration and temperature of burning) of the belite clinker preparation on the belite clinker development in time, on belite polymorphism, on the chemical composition of belite crystals and on the belite cement hydraulic activity was studied, too. The research methods used for the investigation involved electron microscopy, optical microscopy, X-ray diffraction analysis, high-temperature microphotometry and calorimetry. The resulting clinkers were hydraulically activated by addition of calcium sulfate. The experiments have proven that the higher rate of belite formation does not lead to the increase of its hydraulic activity, as opposed to that of alite. On the other hand, the chemical activation by sulfate anions enables to prepare clinker with relatively higher degree of lime saturation with minor admixture of alite and anhydrite, which is hydraulically activated. The work was concluded by experimental burning of belite clinker doped with sulfate anions in a model rotary kiln and by the preparation of cements blended with common industrial alite clinker. The results indicate the possibility of separate industrial production of special belite clinker alongside with common alite clinker and the production of economically and environmentally beneficial blended Portland cements with suitable technological parameters, or targeted production of special cements with properties corresponding to their required utilization.
20

Syntéza aluminátosilikátových systémů na bázi geopolymerů orientovaná na využívání sekundárních surovin / Synthesis of Aluminosilicate Systems Based on Alkali Activation of Industrial By-Products

Kalina, Lukáš January 2011 (has links)
Portland cement-based products are the most commonly used building materials. However, it is well known that the production of OPC not only consumes a significant amount of natural resources and energy but also releases high quantity of carbon dioxide (CO2) to the atmosphere. Purpose of this work is to develop new cementitious material similar to Portland cement-based concrete, which is convenient in terms of energy and is environmental-friendly at once. This work presents preparation, composition and properties of inorganic aluminosilicate polymer, called geopolymer, synthesized from blast furnace slag and fly ash, activated by sodium hydroxide and cement kiln dust. Study of the microstructure was based on SEM-EDX-WDX, TG-DTA-EGA and XRD analysis.

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