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Visar resultat 1 - 5 av 10 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. On the microstructure and mechanical properties of Mg-Al alloys

    Författare :Haiping Cao; Linköpings universitet; []
    Nyckelord :Mg-AI; microstructure; mechanical properties; divorced degree; modeling; mould constraint; segregation band; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The microstructural features and the mechanical properties of binary Mg-Al alloys have been investigated by using a gradient solidification technique. Homogeneous and nearly defect-free samples were produced under well controlled cooling conditions, through which the microstructural characteristics as well as the relationships between microstructure and mechanical properties in Mg-AI alloys were precisely defined. LÄS MER

  3. 2. Characteristics of cast magnesium alloys : microstructures, defects and mechanical properties

    Författare :Haiping Cao; Anders Jarfors; Linköpings universitet; []
    Nyckelord :Mg alloys; microstructure; mechanical properties; defects; modelling; segregation bands; hot tear; mould constraint; semi-solid casting.; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : Magnesium is the lightest of all structural metals. As such, and combined  with good mechanical and physical properties, it forms the basis for commercial alloys that have found successful use in a wide variety of applications. LÄS MER

  4. 3. Environmentally Friendly Plasticizers for PVC : Improved Material Properties and Long-term Performance Through Plasticizer Design

    Författare :Annika Lindström; Minna Hakkaraninen; Anders Södergård; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; poly butylene adipate ; poly vinyl chloride ; plasticizers; miscibility; mechanical properties; surface segregation; migration; degradation products; Polymer chemistry; Polymerkemi;

    Sammanfattning : Linear and branched poly(butylene adipate) polyesters with number-average molecular weights ranging from 700 to 10 000 g/mol, and degrees of branching ranging from very low to hyperbranched were solution cast with PVC to study the effects of chemical structure, molecular weight, end-group functionality, and chain architecture on plasticizing efficiency and durability. Miscibility was evaluated by the existence of a single glass transition temperature and a shift of the carbonyl group absorption band. LÄS MER

  5. 4. Mechanisms of unreduced gamete formation in Arabidopsis thaliana

    Författare :Jun Yi; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Polyploidy is a widespread phenomenon in plants, which is commonly believed to arise through the production of unreduced (2n) gametes due to meiotic failure. Despite the importance of unreduced gamete formation for plant polyploidization, the mechanisms leading to their formation are not well understood. LÄS MER

  7. 5. Characterization of Si-based heterostructures prepared by MBE and containing Ge, C, or Er

    Författare :Kenneth B. Joelsson; Karl Eberl; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Silicon molecular beam epitaxy (MBE) has been used to prepare various Si-based structures.The first part of the work concerns hole transport in Si1-xGex layers for Ge contents 0≤x≤0.36 and B-doping concentrations 2-7.5x1018 cm-3. LÄS MER