Sökning: "surface oxide"

Visar resultat 1 - 5 av 681 avhandlingar innehållade orden surface oxide.

  1. 1. ROLE OF SURFACE OXIDES IN SINTERING OF CHROMIUM-ALLOYED STEEL POWDER

    Författare :Henrik Karlsson; Chalmers University of Technology; []
    Nyckelord :water atomisation; surface analysis; sintering; chromium-alloyed steel.; Powder metallurgy; surface reactions; surface; surface oxide; SEM; XRD; AES; XPS;

    Sammanfattning : During water-atomisation and handling of steel powder the surface inevitably oxidises. The surface bound oxide is an important factor in the processing of powder metallurgical (PM) steels, especially in case the powder contains elements forming stable oxides, such as Cr, Mn, and Si. LÄS MER

  2. 2. The effect of surface steps and oxides on the catalytic activity on model Pd and Rh catalysts

    Författare :Chu Zhang; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Surface X-ray diffraction SXRD ; X-ray photonelectron spectroscopy; Catalytic activity; Oxide; Single Crystal surface; surface structure; vicinal surface; CO oxidation; stepped surface; Fysicumarkivet A:2018:Zhang;

    Sammanfattning : A catalyst is a substance that can speed up the rate of a chemical reaction without itself being consumed. Catalysts are crucial for chemical production industries, where about 90% of all chemicals are produced using catalysts. LÄS MER

  3. 3. Bioaccessibility of Stainless Steels : Importance of Bulk and Surface Features

    Författare :Gunilla Herting; Inger Odnevall Wallinder; Stuart Lyon; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Stainless steel; iron; chromium; nickel; corrosion; metal release; artificial rain; synthetic body fluids; acetic acid; surface oxide; surface finish; Surface and colloid chemistry; Yt- och kolloidkemi;

    Sammanfattning : With increasing environmental awareness, the desire to protect human beings and the environment from adverse effects induced by dispersed metals has become an issue of great concern and interest. New policies, such as REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) within the European Community, have been implemented to reduce hazards posed by the use of chemicals on producers and downstream users. LÄS MER

  4. 4. Combined Molecular Dynamics and Embedded-Cluster Calculations in Metal Oxide Surface Chemistry

    Författare :Björn Herschend; Kersti Hermansson; Micael Baudin; Joachim Sauer; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; embedded-cluster; ab initio; molecular dynamics; metal oxide; ceria; magnesium oxide; adsorption; surface defect; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

    Sammanfattning : The development and improvement of the functionality of metal oxides in heterogeneous catalysis and other surface chemical processes can greatly benefit from an atomic-level understanding of the surface chemistry. Atomistic calculations such as quantum mechanical (QM) calculations and molecular dynamics (MD) simulations can provide highly detailed information about the atomic and electronic structure, and constitute valuable complements to experimental surface science techniques. LÄS MER

  5. 5. Transition metal oxide surfaces : Surface structures and molecular interaction

    Författare :Markus Soldemo; Jonas Weissenrieder; Mats Göthelid; Sarp Kaya; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; Physics; Fysik;

    Sammanfattning : Metal oxides are both corrosion products and useful materials with a wide range of applications. Two of the most used metals today are iron and copper. In this thesis, surface structures and molecular interaction with surfaces of iron oxides and copper oxides are studied using spectroscopy and microscopy methods. LÄS MER