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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.
21

Samozhutnitelné betony SCC pro monolitické konstrukce / Self-compacting concrete SCC for monolithic construction

Gajdoš, Jan January 2015 (has links)
This thesis contains two parts: theoretical and experimental. In the theoretical part are described materials for production SCC and their effect on the properties of fresh and hardened concrete. Practical part is divided into two experiments. First experiment deals with the design, production and properties of hardened SCC strength classes C16/20, C20/25 and C25/30 with high volume fly ash and inert admixtures. The main endpoints were long-term compressive strength and modulus of elasticity. Second experiment of practical part deals with designs SCC with modulus of elasticity more than 40 kN/mm2.
22

Studium pojivového systému pro žárobetony na bázi kyseliny fosforečné a hlinitanového cementu / The study of the refractory concrete binding system based on phosphoric acid and aluminous cement

Pavlík, Tomáš January 2020 (has links)
This thesis deals with refractory concrete binding system based on aluminous cement and phosphoric acid. The prepared refractory concretes were fired at 1 000 °C. Various effects on compressive strength of refractory concrete were studied. The influence of aluminous cement content and phosphoric acid content, the influence of various admixtures, the influence of plasticizers and the influence of time and method of sample storage were studied. Simultaneous thermogravimetry and differential thermal analysis of the basic unfired sample were performed. Finally, selected refractory concretes were fired at 110, 200, 400, 600, 800, 900, 1 000 and 1 100 °C. The compressive strength of these samples was measured and powder X ray diffraction analysis was performed. The compressive strength of refractory concretes under intermediate temperatures (800–1 100 °C) was most increased in samples with metakaolin and gray microsilica.
23

Proces zavádění robotizace ve výrobě zásobníku tlaku pro vstřikovací systém common rail / Integration od robot in production of pressure tank for common rail system

Krejčí, Monika January 2020 (has links)
This diploma thesis is about integration process of assembly line automation on rail assembly. In the beginning is introduced Bosch Company, then follows up theoretical part about automation and assembly lines. After theoretical introduction continues description of current state of rail assembly and choice the best line for automation and its detailed description. After that, the work deals with finding of the best solution for line automation. Found solutions are evaluated using the decision matrix. After the best one of them is chosen. There is also calculation of investments, because the one of important conditions is, that payback period has to be less than two years. Next step is choice of the most suitable supplier and integrator, which can cope with all requirements. At the end of thesis is analysis of risks done and thanks to this, are potentials for improvement of workplace safety found.
24

Latexy modifikované cementové materiály / Latexes modified cementitious materials

Vinter, Václav January 2008 (has links)
In this thesis, the development of mechanical properties and structure of latex modified cementious materials during hydration was studied. Latex modified materials are composites of inorganic cement (portland cement) and organic polymer latex. Preparation, processing and fabrication of the polymer cement material based on portland cement was optimized with aim to reach the most compact structure of the product with the finest mechanical characters. The experimental part was pointed to observe influence of the type and amount of polymer latex with focus on mechanical characters and hydration kinetics with given filling as well as without it. In presented work, the possibility of compaction of the material by high-shear mixing within twin-roll mixer (the prototype for production of MDF composite) was verified. The second part of the labor was aimed to analysis of prepared polymer-cementitious material. For determination of influence of batching of added polymer latex on hydration of cement paste the thermal analysis (DTA/TGA) and infrared spectroscopy of composite was done. At last the microscopic observation by optical microscope was carried.
25

Dynamická tenziometrie ve výzkumu biokoloidů / Dynamic tensiometry of biocolloids

Kulilová, Pavlína January 2008 (has links)
Hyaluronová kyselina je v současné době velmi významná biomolekula používaná v medicíně a kosmetice, a její výzkum je důležitý pro další budoucí použití. Zaměření této práce je studování povrchových vlastností hyaluronové kyseliny, jejích hydrofobních derivátů a roztoků SDS pro srovnání, za použití tenziometrie. Tyto sloučeniny byly zkoumány ve vodě a v roztocích ve formě sodné soli. Sledované vzorky byly měřeny dvěmi metodami v různých koncentračních rozmezích při laboratorní teplotě pomocí nového BPA-800P bublinového tenziometeru. Byly navrženy takové experimenty, aby se zjistily využitelné možnosti tohoto přístroje pro další výzkum. Výsledky práce ukazují rozdílnosti jednotlivých povrchově aktivních látek v závislosti na jejich koncentraci a použitém prostředí. Hyaluronová kyselina nevykazuje povrchovou aktivitu, zatímco její deriváty a SDS ano.
26

Kontrast v obraze získaném pomocí scintilačního detektoru sekundárních elektronů ve VP SEM / Contrast in image aquired by scintillation SE detector for VP SEM

Koudela, Oldřich January 2011 (has links)
First part of this thesis is a theoretical essay which deals with the basics of scanning electron microscopy, with structure and function of a scanning electron microscope, its’ special case of an various pressure scanning electron microscope, electron interaction with surrounding environment and with a scintillation detector. The applied part of the thesis is focused on evaluation of material contrast on Cu-W specimen. Material contrast is evaluated for different pressures of water vapors in the microscope specimen chamber and for different detection conditions.
27

Využití tlustých vrstev v moderní elektronice / Application of Thick Films in the Modern Electronics

Somer, Jakub January 2013 (has links)
Tato diplomová práce se zabývá technologií tlustých vrstev a jejím možným použitím pro nekonvenční aplikace. První část práce je rešeršní a zaměřuje se především na aplikace tlustovrstvé technologie v různých oblastech použití. V teoretické části práce je dále popsána technologie LTCC, včetně technologických postupů výroby. V praktické části jsou řešeny dvě aplikace v tlustovrstvé technologii. Jedná se návrh a výrobu vysokofrekvenčního filtru a optického senzoru tlaku technologií LTCC. V závěru práce jsou provedena měření a jsou zhodnoceny dosažené výsledky.
28

Měření na turbínové mříži / Measurements on Turbine Cascade

Vondra, Marek January 2015 (has links)
The Aim of this Diploma thesis is the measurement on turbine cascade. The first part is focused on measurement of the flow characteristics of the turbine cascade using a three–hole pressure probe. The second part includes the blade profile pressure measurement. Both measurements are performed both experimentally and by computer simulation in Ansys and the results are compared. Part of the work is also file containining the computer simulation, which was carried out in CFX program.
29

Analýza diesterů diolů v novorozeneckém mázku pomocí HPLC/APCI-MS2 / Analysis of diol diesters in vernix caseosa using HPLC/APCI-MS2

Šubčíková, Lenka January 2014 (has links)
Vernix caseosa is a natural biofilm which covers the skin of a human fetus from the third trimester of pregnancy. It has hydrating, regenerating and anti-microbial effects. The components responsible for these properties of vernix caseosa could be used in the pharmaceutical and cosmetic industries. For this reason, the total composition is analyzed. The lipid components of vernix caseosa consist of squalene, wax esters, sterol esters, 1,2-diol diesters, triacylglycerides, free fatty acids, fatty alcohols, cholesterol, diacylglycerides, monoacylglyceridesů and phospholipids . This study is focused on structure analysis of the 1,2-diol diesters of vernix caseosa. Conditions were optimized for the HPLC separation. Nova -Pak C18 column was used and a gradient of acetonitrile:ethyl acetate was chosen as a mobile phase. Before entering the APCI source ammonium formate was added; ammonium adducts [M +18]+ were formed. Eight scan events was set in MS method. One for the full scan spectrum, second for MS2 spectrum of the precursor ions and six MS3 data-dependent spectra. The position of the double bonds of unsaturated 1,2-diol diesters was determined by fragmentation of their [M+C3H5N]+ adducts. There were identified over 2200 of 1,2-diol diesters differing in lengths of alcohol and fatty acid chains, and...
30

Možnosti uplatňování štíhlé výroby ve vybraném podniku / Possibilities of implementation the lean production in the choosen company

MALATÍNOVÁ, Lenka January 2015 (has links)
The aim of this thesis work is to evaluate the functioning of the already established elements of lean production, analyze production effectiveness before and after the introduction of these elements in the choosen company. This thesis characterizes the production before the introduction of lean production and shows deficiencies in the production process. These deficiencies have been eliminated implementation of lean production on the line. Subsequently indicators are evaluated before and after the introduction of the lean production. The experiment participants explains the principle of push and pull, one-piece-flow or customer tact.An integral part of the implementation of lean manufacturing was 5S method. It was proposed posible improvements for enterprise . It was recommended to conduct thorough supplier evaluation and subsequent communication with them. Other recommendations focused on Kaizen management, which is a system for proposals to improve employees.

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