Search for dissertations about: "thermal activation"

Showing result 1 - 5 of 115 swedish dissertations containing the words thermal activation.

  1. 1. Photon stimulated CVD of amorphous carbon thin films : By Mikael Lindstram

    Author : Mikael Lindstam; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Chemistry; photolysis; thermal activation; CVD; amorphous carbon; modelling; kinetics; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

    Abstract : Amorphous carbon has attracted much interest for several decades now because of its complex crystal structure and microstructure. Depending on the carbon sp2/sp3 bonding ratio, these materials yield a broad spectrum of useful properties; which can be tailored for specific applications. READ MORE

  2. 2. Investigations of the Kinetics of Reduction and Reduction/Carburization of NiO-WO3 Precursors

    Author : Hesham M. Ahmed; Seshadri Seetharaman; Ricardo Morales Estrella; Hesham Ahmed; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduction; Reduction-Carburization; Gas-solid Reactions; Kinetics; Hydrogen; Methane; Thermogravimetric analysis; Fluidized bed; Simulation; Thermal diffusivity; Thermal conductivity; Laser flash; Metallurgical process engineering; Metallurgisk processteknik; Process Metallurgy; Processmetallurgi;

    Abstract : Kinetic studies of reduction of the mixtures of NiO and WO3 having different Ni/(Ni+W) molar ratios in flowing hydrogen gas were investigated by means of Thermo Gravimetric Analysis (TGA), Fluidized Bed (FB) technique as well as Thermal diffusivity measurements under isothermal conditions. In the case of TGA, the reaction progress was monitored by mass loss, while evolved gas analysis by a gas chromatograph was the indicator of the reaction progress in the case of FB. READ MORE

  3. 3. The Plastic Flow Behaviour of Aluminium Alloys Exhibiting Dynamic Strain Ageing

    Author : Magnus Hörnqvist; Chalmers University of Technology; []
    Keywords : Dynamic strain ageing; Portevin-Le Chatelier effect; Temperature sensitivity; Strain rate sensitivity; Al-Zn-Mg; Thermal activation;

    Abstract : The phenomenon known as dynamic strain ageing, abbreviated DSA, has been known since the beginning of last century. It was first discovered as serrations in the load-elongation curve obtained upon deforming specimens of certain alloys in tension. This phenomenon became known as the Portevin-Le Chatelier (PLC) effect. READ MORE

  4. 4. Innovative process solutions towards recycling of salt cake from secondary aluminum smelting

    Author : Peng Li; Lidong Teng; Sankaran Subramanian; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal diffusivity; Model; Solubility; CO2; AlN; Crystals; Hydrolysis; Enhance; Hinder; Leaching; Absorption; Synthesis; SiMgAlON; Oxidation; Arctan; Activation energy; Mullite; Liquid; Crystallization.; SRA - Production; SRA - Produktion;

    Abstract : To offer better solutions for the recycling of salt cake from secondary aluminum melting, several innovative investigations were carried out based on hydrometallurgical and pyrometallurgical views.Thermal diffusivity measurements as a function of temperature on salts-Al composites having various compositions (0, 2, 4, 6, 8, 10, 12wt pct metallic Al) were carried out. READ MORE

  5. 5. Structure, Morphology, and Catalytic Properties of CuOx/CeO2 Model Catalysts

    Author : Björn Skårman; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Synchrotron radiation; High-energy Diffraction; X-ray Absorption Fine Structure Spectroscopy.; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Chemistry; Kemi; Material technology; Materiallära; materialteknik; X-ray photoelectron spectroscopy; Atomic force microscopy; Gatan Image Filter GIF ; Energy-filtered TEM; High-resolution electron microscopy; Inert gas condensation IGC ; rf Magnetron sputtering; Thermal activation; Batch reactor; Carbon monoxide oxidation; Surface sensitivity; Catalytic anisotropy; Growth; Nucleation; Topography; Roughness; Core-shell structures; Morphology; Nanostructured; Nanocomposite; Nanoparticles; Surface structure; Polycrystalline surfaces; Thin films; Copper oxide; Cerium dioxide CeO2 ; Ceria;

    Abstract : Cerium dioxide, or ceria, is a chemically stable oxygen ion conducting material with a capacity to store and release oxygen, and is therefore extensively used in combustion catalysts. The Cu-Ce-O system has been identified as one of the most active catalysts for the combustion of carbon monoxide. READ MORE