Search for dissertations about: "hydrogen and oxygen diffusion"

Showing result 1 - 5 of 32 swedish dissertations containing the words hydrogen and oxygen diffusion.

  1. 1. Modified oxygen and hydrogen transport in Zr-based oxides

    Author : Clara Anghel; Gunnar Hultquist; Magnus Limbäck; Truls Norby; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Zirconia; Zirconium; Zircaloy; hydrogen and oxygen diffusion; SPP; oxygen dissociating elements; oxidation; dissociation; hydration; CO adsorption; molecular transport; porosity.; Materials science; Teknisk materialvetenskap;

    Abstract : Most metals and alloys in the presence of oxygen and moisture will instantaneously react and form a thin (2-5 nm) surface oxide layer. For further reaction to occur, oxygen ions and/or metal cations often diffuse through the already formed oxide layer. READ MORE

  2. 2. Alternative methods for analysing moisture transport in buildings : Utilisation of tracer gas and natural stable isotopes

    Author : Kjartan Gudmundsson; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tracer gas; water vapour permeability; diffusion; surface diffusion; isotopic analysis; deuterium; oxygen-18; fractionation; vapour barrier; transient numerical modelling of diffusion; Building engineering; Byggnadsteknik;

    Abstract : New methods, based on tracer gas measurements and isotopicanalysis can be used to evaluate the moisture properties ofbuilding materials and provide the means for forensic analysisof the origins and history of excessive water in buildings, theimmediate practical consequences of which will be the abilityto improve the moisture performance of constructions. It is shown, in theory and through measurements how thewater vapour permeability of porous building materials can witha good degree of accuracy be estimated with tracer gasmeasurements that provide an efficient alternative to the cupmethod. READ MORE

  3. 3. Alumina Thin Films : From Computer Calculations to Cutting Tools

    Author : Erik Wallin; Ulf Helmersson; Patrick Desjardins; Linköpings universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Alumina; thin films; coatings; sputtering; density functional theory; high power impulse magnetron sputtering; HIPIMS; Material physics with surface physics; Materialfysik med ytfysik; Surface engineering; Ytbehandlingsteknik; Surfaces and interfaces; Ytor och mellanytor;

    Abstract : The work presented in this thesis deals with experimental and theoretical studies related to alumina thin films. Alumina, Al2O3, is a polymorphic material utilized in a variety of applications, e.g., in the form of thin films. READ MORE

  4. 4. Escape to space or return to venus : ion flows measured by venus express

    Author : Moa Persson; Yoshifumi Futaana; Hans Nilsson; Maria Hamrin; Dmitrij Titov; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Venus; water; escape; planetary physics; oxygen; O ; hydrogen; H ; ions; space physics; space plasma physics; Venus Express; ASPERA-4; IMA; spacecraft measurements; rymd- och plasmafysik; Space and Plasma Physics;

    Abstract : The present-day Venusian atmosphere is crushingly dense, extremely hot and arid. Yet, in its early history, Venus presumably had a massive amount of water, which, if spread evenly over the surface, provided a water depth of 10s to 100s of meters. Therefore, over the course of the atmospheric evolution, the water must have been removed from Venus. READ MORE

  5. 5. Studies of transport in oxides on Zr-based materials

    Author : Clara Anghel; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Zirconium; hydrogen; oxygen diffusion; second-phase particle; oxidation; dissociation; hydration; carbon monoxide; adsorption; porosity; Other materials science; Övrig teknisk materialvetenskap;

    Abstract : Zr-based materials have found their main application in the nuclear field having high corrosion resistance and low neutron absorption cross-section. The oxide layer that is formed on the surface of these alloys is meant to be the barrier between the metal and the corrosive environment. READ MORE