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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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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.
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Showing 951 to 960 of 962 (0.137 seconds)| 951 |
Kalibrace experimentálního zařízení pro testování kosmických technologií / Calibration task of experimental device for space technology testingLazar, Václav January 2019 (has links)
Diplomová práce se zabývá možnosti kalibrace experimentálního testovacího zařízení. Zejména se věnuje návrhu termálního matematického modelu popisujícího tepelné procesy uvnitř zařízení v průběhu měření tepelné vodivosti vzorku. První část práce je věnována seznámení se s testovacím zařízením, jeho limity a principem měření. Popisuje řešení třetí verze testovací komory, společně s nezbytnými úpravami, provedenými za účelem zajištění předepsaných simulačních podmínek. Zmiňuje také potřebu a důvody kalibrace. Druhá část je především zaměřená na návrh kalibračních vzorků a termálního modelu. Uvádí definované požadavky a konečné vlastnosti vyrobených vzorků. Matematický model prezentuje postup výpočtu zjištěných tepelných ztrát a poukazuje na možnosti jejich zpřesnění. Testování kalibračních vzorků bylo provedeno na nově zprovozněné třetí verzi testovací komory. Naměřené výsledky poslouží k ladění termálního modelu, nezbytného k dokončení kalibračního procesu, který umožní přikročení k další fázi testování v experimentální komoře.
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Experimentální ověření pasivních prvků tepelné regulace družic / Experimental study on satellite´s passive thermal-regulation unitsMateášik, Timko Marek January 2021 (has links)
Diplomová práca sa zaoberá vplyvom termálnych medzivrstiev na tepelnú kontaktnú vodi- vosť a tepelný kontaktný odpor. Práca sa zameriava na aplikáciu termálnych medzivrstiev pre vylepšenie tepelnej kontaktnej vodivosti v tepelnom spínači a v kozmických zariade- niach obecne. Teoretická časť práce stručne skúma rôzne pasívne termálne kontrolné systémy použí- vane v kozmických zariadeniach, vrátane termálnych medzivrstiev, a vysvetľuje pozadie tejto práce. Táto práca ďalej skúma rôzne termálne medzivrstvy, predovšetkým povlaky a fólie, a uvádza výber vhodnej termálnej medzivrstvy. Experimentálna časť práce skúma povrchové parametre, tepelnú vodivosť a mikrotvr-dosť medených vzoriek, ktoré slúžia ako substrát pre povlak čistého striebra. Ďalej rieši podmienky merania, metódy vyhodnocovania a samotné experimentálne merania. Experimentálne merania sú vykonané v termo-vákuovej testovacej komore a na základe výsledkov sú vyvodené závery. Pre ďalšiu prácu sú uvedené doporučenia.
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Použití mobilního robotu v inteligentním domě / Mobile robot in smart houseKuparowitz, Tomáš January 2013 (has links)
Aim of this thesis is to search the market for suitable autonomous robot to be used by smart house. The research in this work is partly done on the range of abilities of smart houses in matter of sensor systems, ability of data processing and their use by mobile robots. The output of this thesis is robotics application written using Microsoft Robotics Developer Studio (C#) and simulated using Visual Simulation Environment. Main feature of this robotic application is the interface between robot and smart house, and robot and user. This interface enables employer to directly control robot's movement or to use automated pathfinding. The robot is able to navigate in dynamic environment and to register, interact and eventually forget temporary obstacles.
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Development of the Solution-Spray Flash-Vacuum-Pyrolysis Technique in the Synthesis of Allenyl Isothiocyanates and Synthesis of Complex 2-Amino-1,3-thiazole DerivativesRichter, Frank 29 June 2015 (has links)
Gas-phase thermolysis is a long-known and well established method for the preparation of reactive species. It is, however, limited to relatively volatile substances, which are easily vaporised. In the present work, the solution-spray technique for preparative scale was developed. With this technique, it is possible to subject low-volatile substances, which hardly vaporise even under high-vacuum conditions, to gas-phase thermolysis. By utilising oil nozzles used in heating and burner systems, it was possible to integrate a stable solution-spray into the existing flash-vacuum-pyrolysis system. The influence of several variables, such as flow-rate, pressure, temperature and solvent was determined. The solution-spray technique was applied in [3,3]-sigmatropic rearrangements of certain propargyl thiocyanates to the corresponding allenyl isothiocyanates.
Furthermore, the parent compound propa-1,2-dienyl isothiocyanate was reacted with various sterically demanding primary and secondary amines to form 2-amino-1,3-thiazoles in moderate to excellent yields. Based on this, a catalyst-free four-center three-component reaction was developed. 2-Amino-1,3-thiazoles with complex substituents in 5-position at the heterocyclic ring are formed. Reaction mechanisms are discussed to explain the occurance of a highly substituted 1,3-thiazine structure. The influence of reaction temperature, concentrations and solvent were determined and are also discussed.
It was shown that 2-amino-5-methyl-1,3-thiazoles are the apparently first aromatic substance class, that readily undergoes Prins-type 1,3-dioxane ring-formation. / Die Gasphasenthermolyse ist eine lang bekannte und etablierte Methodik zur Synthese reaktiver Spezies. Sie ist allerdings auf flüchtige Substanzen mit einer guten Verdampfbarkeit beschränkt. Für schwerflüchtige Verbindungen, welche sich selbst im Hochvakuum nur mäßig oder gar nicht in die Gasphase bringen lassen, wurde in der vorliegenden Arbeit die Solution-Spray-Technik für die Anwendung im präparativen Maßstab entwickelt. Unter Verwendung von Ölzerstäuberdüsen, wie sie in der Heizungs- und Brennertechnik Anwendung finden, wurde die Erzeugung eines stabilen Lösungs-Sprays in die vorhandene Blitzvakuumpyrolyse-Technik integriert. Der Einfluss verschiedener Variablen, wie Flussrate, Druck, Temperatur und Lösungsmittel wurde untersucht. Die Solution-Spray-Technik wurde für die [3,3]-sigmatrope Umlagerung bestimmter Propargylthiocyanate zu Allenyl-isothiocyanaten angewendet.
Des Weiteren wurde Propa-1,2-dienylisothiocyanat – das einfachste Allenylisothiocyanat – mit diversen sterisch anspruchsvollen primären und sekundären Aminen in mäßigen bis exzellenten Ausbeuten zu 2-Amino-1,3-thiazolen umgesetzt. Darauf aufbauend konnte eine Vier-Zentren-drei-Komponenten-Reaktion entwickelt werden. Es entstehen in hohen Ausbeuten 2-Amino-1,3-thiazole mit komplexen Substituenten an der 5-Position des Heterocyclus. Reaktionsmechanismen werden diskutiert um die alternative Bildung einer hochsubstituierten 1,3-Thiazinstruktur zu erklären. Der Einfluss von Reaktionstemperatur, Konzentration und Lösungsmittel auf das Produktverhältnis wurde ebenfalls untersucht und wird diskutiert.
Es konnte gezeigt werden, dass 2-Amino-5-methyl-1,3-thiazole als offenbar erste aromatische Substanzklasse sehr gute Substrate für die Bildung von 1,3-Dioxanen nach Prins darstellen.
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Construção de um sistema experimental para desaceleração de átomos. / Construction of an experimental system for stopping atoms.Firmino, Marcel Eduardo 21 March 1991 (has links)
Neste trabalho apresentamos a construção e teste de um sistema experimental que nos permite produzir um fluxo intenso de átomos lentos. Discutimos o desenho e construção do solenóide que compensa o efeito Doppler que surge durante o processo de desaceleração, as câmaras de vácuo, o forno que gera o feixe atômico e o sistema ótico utilizado. Estudamos a técnica de desaceleração de átomos pelo ajuste Zeeman. Uma nova técnica de observação que consiste no acompanhamento da fluorescência do feixe ao longo do caminho de desaceleração é usada, o que nos permite uma observação direta do processo. / This work presents the development and test of an experimental set-up which allows to produce a very strong slow motion atomic beam. We discuss the calculation and construction of the solenoid to compensate the Doppler effect arising during the deceleration process, vacuum chambers, the oven which produces the atomic beam and the optical system used. We have studied the Zeeman-tuned technique to slow an atomic beam of sodium atoms. A new technique to study the deceleration which Consist in monitoring the fluorescence along the deceleration path is used, which allow us a direct observation of the process.
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Construção de um sistema experimental para desaceleração de átomos. / Construction of an experimental system for stopping atoms.Marcel Eduardo Firmino 21 March 1991 (has links)
Neste trabalho apresentamos a construção e teste de um sistema experimental que nos permite produzir um fluxo intenso de átomos lentos. Discutimos o desenho e construção do solenóide que compensa o efeito Doppler que surge durante o processo de desaceleração, as câmaras de vácuo, o forno que gera o feixe atômico e o sistema ótico utilizado. Estudamos a técnica de desaceleração de átomos pelo ajuste Zeeman. Uma nova técnica de observação que consiste no acompanhamento da fluorescência do feixe ao longo do caminho de desaceleração é usada, o que nos permite uma observação direta do processo. / This work presents the development and test of an experimental set-up which allows to produce a very strong slow motion atomic beam. We discuss the calculation and construction of the solenoid to compensate the Doppler effect arising during the deceleration process, vacuum chambers, the oven which produces the atomic beam and the optical system used. We have studied the Zeeman-tuned technique to slow an atomic beam of sodium atoms. A new technique to study the deceleration which Consist in monitoring the fluorescence along the deceleration path is used, which allow us a direct observation of the process.
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Funkční zkouška tepelného spínače pro prostředí planety Mars / Qualification test of heat switch for Martian conditionsMašek, Jakub January 2016 (has links)
Diplomová práce se zabývá studiem projektu tepelného spínače a dosažených výsledků. Zaměřuje se především na vývoj zařízení pro zkoušení tepelného spínače v podmínkách odpovídající prostředí planety Marsu. První část práce se zabývá především popisem vývoje zkušební komory určené pro simulaci extrémních podmínek, tj. nízkého tlaku a teplot, od předběžného návrhu až po konečnou podobu komory, která bude použita pro předepsané zkoušky. Práce popisuje také důvody úprav některých částí komory a uvádí návrhy řešení nepředvídaných událostí, které vznikly v průběhu testů. Cílem druhé části práce je návrh kampaně pro zkoušení tepelného spínače od úvodních zkoušek ověření základní funkčnosti komory, přes ověření vlastností a nastavení všech systémů měřícího zařízení, až po zkoušky na prvních vzorcích a závěrečném kvalifikačním modelu tepelného spínače. Dále se práce zaměřuje na postup vyhodnocení naměřených dat a jevů, které jej ovlivňují. Kalibrační zkoušky zařízení, systémů a postupu vyhodnocení naměřených dat, které byly provedeny na speciálně navržených náhradních vzorcích, jsou téměř u konce. Jakmile budou výsledky schváleny, zkušební komora i navržené postupy měření budou připraveny pro požadované zkoušení vzorků tepelného spínače.
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Kondenzační technika a odvody spalin / Condensing technology and flue gasMüller, Jan January 2014 (has links)
This thesis is developed as a proposal for heating for a primary school and kindergarten in the region of Brno-countryside. For the insulated building, a combination of heating and air-conditioning is proposed. The concept is designed so that the air-conditioning preheats the exterior air and the heating system warms the incoming air to a comfortable temperature. For the required thermal performance, sources of heat (for gas and pellets) and a layout solution for the boiler room is designed. Drainage of combustion products is proposed for both solutions. The project solution is per the extent of the construction permit. The theoretical part is linked with the practical part through the condensation boilers, their function and division, and drainage of combustion products. The experiment for the given topic was conducted on the drainage of combustion products. The pressure loss of the reverse knob was determined in relation to the flow rate of air in the condensation boilers as this loss is essential in assessing the drainage of combustion products.
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“Accumulation by Dispossession” by the Global Extractive Industry: The Case of CanadaKinuthia, Wanyee 13 November 2013 (has links)
This thesis draws on David Harvey’s concept of “accumulation by dispossession” and an international political economy (IPE) approach centred on the institutional arrangements and power structures that privilege certain actors and values, in order to critique current capitalist practices of primitive accumulation by the global corporate extractive industry. The thesis examines how accumulation by dispossession by the global extractive industry is facilitated by the “free entry” or “free mining” principle. It does so by focusing on Canada as a leader in the global extractive industry and the spread of this country’s mining laws to other countries – in other words, the transnationalisation of norms in the global extractive industry – so as to maintain a consistent and familiar operating environment for Canadian extractive companies. The transnationalisation of norms is further promoted by key international institutions such as the World Bank, which is also the world’s largest development lender and also plays a key role in shaping the regulations that govern natural resource extraction. The thesis briefly investigates some Canadian examples of resource extraction projects, in order to demonstrate the weaknesses of Canadian mining laws, particularly the lack of protection of landowners’ rights under the free entry system and the subsequent need for “free, prior and informed consent” (FPIC). The thesis also considers some of the challenges to the adoption and implementation of the right to FPIC. These challenges include embedded institutional structures like the free entry mining system, international political economy (IPE) as shaped by international institutions and powerful corporations, as well as concerns regarding ‘local’ power structures or the legitimacy of representatives of communities affected by extractive projects. The thesis concludes that in order for Canada to be truly recognized as a leader in the global extractive industry, it must establish legal norms domestically to ensure that Canadian mining companies and residents can be held accountable when there is evidence of environmental and/or human rights violations associated with the activities of Canadian mining companies abroad. The thesis also concludes that Canada needs to address underlying structural issues such as the free entry mining system and implement FPIC, in order to curb “accumulation by dispossession” by the extractive industry, both domestically and abroad.
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“Accumulation by Dispossession” by the Global Extractive Industry: The Case of CanadaKinuthia, Wanyee January 2013 (has links)
This thesis draws on David Harvey’s concept of “accumulation by dispossession” and an international political economy (IPE) approach centred on the institutional arrangements and power structures that privilege certain actors and values, in order to critique current capitalist practices of primitive accumulation by the global corporate extractive industry. The thesis examines how accumulation by dispossession by the global extractive industry is facilitated by the “free entry” or “free mining” principle. It does so by focusing on Canada as a leader in the global extractive industry and the spread of this country’s mining laws to other countries – in other words, the transnationalisation of norms in the global extractive industry – so as to maintain a consistent and familiar operating environment for Canadian extractive companies. The transnationalisation of norms is further promoted by key international institutions such as the World Bank, which is also the world’s largest development lender and also plays a key role in shaping the regulations that govern natural resource extraction. The thesis briefly investigates some Canadian examples of resource extraction projects, in order to demonstrate the weaknesses of Canadian mining laws, particularly the lack of protection of landowners’ rights under the free entry system and the subsequent need for “free, prior and informed consent” (FPIC). The thesis also considers some of the challenges to the adoption and implementation of the right to FPIC. These challenges include embedded institutional structures like the free entry mining system, international political economy (IPE) as shaped by international institutions and powerful corporations, as well as concerns regarding ‘local’ power structures or the legitimacy of representatives of communities affected by extractive projects. The thesis concludes that in order for Canada to be truly recognized as a leader in the global extractive industry, it must establish legal norms domestically to ensure that Canadian mining companies and residents can be held accountable when there is evidence of environmental and/or human rights violations associated with the activities of Canadian mining companies abroad. The thesis also concludes that Canada needs to address underlying structural issues such as the free entry mining system and implement FPIC, in order to curb “accumulation by dispossession” by the extractive industry, both domestically and abroad.
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