Sökning: "scale chemistry"

Visar resultat 16 - 20 av 512 avhandlingar innehållade orden scale chemistry.

  1. 16. Atomic Scale Degradation of Zirconium Alloys for Nuclear Applications

    Författare :Gustav Sundell; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Irradiation damage; Hydrogen microanalysis; Hydrogen pick-up; Zirconium alloys; Atom probe tomography; Corrosion;

    Sammanfattning : Due to their low thermal neutron capture cross-section, zirconium alloys are widely used in the nuclear industry as fuel cladding and for structural components. The lifetime of the fuel assemblies in the reactors is primarily dictated by the ability of the cladding to withstand oxidation and hydrogen pick-up from the coolant water and radiation damage induced by the neutron flux. LÄS MER

  2. 17. Structure and spectroscopy of bio- and nano-materials from first-principles simulations

    Författare :Weijie Hua; Yi LUO; Mauro Stener; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; soft x-ray spectroscopy; bio- and nano-materials; first-principles simulation; host-guest interaction; generalized energy-based fragmentation; Quantum chemistry; Kvantkemi; Spectroscopy; Spektroskopi; SRA - Molecular Bioscience; SRA - Molekylär biovetenskap;

    Sammanfattning : This thesis is devoted to first-principles simulations of bio- and nano-materials,focusing on various soft x-ray spectra, ground-state energies and structures of isolated largemolecules, bulk materials, and small molecules in ambient solutions. K-edge near-edge x-ray absorption fine structure (NEXAFS) spectra, x-ray emission spectra, andresonant inelastic x-ray scattering spectra of DNA duplexes have been studied by means oftheoretical calculations at the density functional theory level. LÄS MER

  3. 18. Structure and chemical ordering in metallic nanoparticles from atomic scale modeling

    Författare :Magnus Rahm; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nanoparticles; regular truncated octahedron; chemical ordering; nanoparticle shapes; molecular dynamics; icosahedron; Monte Carlo; modeling; Marks decahedron; nanoparticle structures;

    Sammanfattning : In the last decades, a wide range of attractive properties have put metallic nanoparticles in the spotlight. These properties, often related to optical response and catalytic performance, are to a large extent dependent on structure and chemical ordering, that is, the distribution of elements in the nanoparticle. LÄS MER

  4. 19. Interactions between non-polar surfaces in water: Fokus on talc, pitch and surface roughness effects

    Författare :Viveca Wallqvist; Per Claesson; Janne Laine; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Talc; surface forces; capillary attraction; hydrophobic interaction; pitch control; wetting agent; dispersing agent; adsorption; imbibition; absorption; permeation; atomic force microscopy; colloidal probe; Hamaker constant; surface roughness; nanostructure.; Talk; kapillärattraktion; ytkrafter; hydrofob växelverkan; hartskontroll; vätningsmedel; dispergeringsmedel; adsorption; uppsugning; absorption; permeabilitet; atomkraftsmikroskopi; kolloidal partikel; Hamakerkonstant; ytråhet; nanostrukturerad yta.; Surface and colloid chemistry; Yt- och kolloidkemi; Physical chemistry; Fysikalisk kemi; Chemistry; Kemi;

    Sammanfattning : The aim of this thesis work was to gain understanding of the interactions between talc mineral and surfaces, liquids and chemicals relevant for industrial applications, such as pulp and paper. Talc is used in the pulp and paper industry as a filler pigment, in control of pitch (lipophilic extractives) deposits and as a coating pigment. LÄS MER

  5. 20. Aspects of Ash Transformations in Pressurised Entrained-Flow Gasification of Woody Biomass : Pilot-scale studies

    Författare :Charlie Ma; Marcus Öhman; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; woody biomass; gasification; ash transformation; slag behaviour; refractory corrosion; Energiteknik; Energy Engineering;

    Sammanfattning : Pressurised entrained-flow gasification (PEFG) of woody biomass has the potential to produce high purity syngas for the production of vital chemicals, e.g., biofuels. However, ash-related issues such as reactor blockages and refractory corrosion need to be addressed before this potential can be realised from a technical perspective. LÄS MER