Sökning: "surface elements"

Visar resultat 1 - 5 av 624 avhandlingar innehållade orden surface elements.

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

    Författare :Henrik Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  3. 2. Perceptual Surface Reconstruction

    Författare :Jens Månsson; Kognitionsvetenskap; []
    Nyckelord :HUMANIORA; HUMANITIES; system; kontroll; Psychology; Psykologi; numerisk analys; Datalogi; systems; control; numerical analysis; Surface; Contour; Depth; Vision; Binocular; Computer science;

    Sammanfattning : How does the brain transform the 2-D light arrays in our eyes into a meaningful 3-D description of surfaces around us? What assumptions does the visual system make about the world when information is incomplete? And how are these assumptions computationally expressed in this perceptual reconstruction process? These questions, and other aspects of binocular depth perception are analysed from a theoretical and computational perspective, as well as through empirical investigations. In paper one, the fundamentals of stereopsis are briefly reviewed, and the difficulties related with resolving the (stereo) correspondence problem are particularly discussed. LÄS MER

  4. 3. Adsorption of surface active elements on the iron (100) surface : A study based on ab initio calculations

    Författare :Weimin Cao; Seshadri Seetharaman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sulfur; oxygen; surface adsorption; iron surface; ab initio calculations; adsorption energy; work function; difference charge density; thermodynamic stability; average velocity; Materials science; Teknisk materialvetenskap;

    Sammanfattning : In the present work, the structural, electronic properties, thermodynamic stability and adatom surface movements of oxygen and sulfur adsorption on the Fe surface were studied based on the ab initio method. Firstly, the oxygen adsorbed on the iron (100) surface is investigated at the three adsorption sites top, bridge and hollow sites, respectively. LÄS MER

  5. 4. Surface Chemical Characteristics of Chromium-alloyed Steel Powder and the Role of Process Parameters during Sintering

    Författare :Dimitris Chasoglou; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbothermal reaction; sintering atmosphere; depth profiling; XPS AES; HR SEM EDX; water atomized powder; surface coverage; reduction oxidation; PM steels; sintering; Cr-Mn-spinel oxides; surface oxides;

    Sammanfattning : Powder Metallurgy (PM) is a cost efficient method suitable for sustainable production of structural parts that have strict dimensional tolerances and complex geometries. It has been a common practice to utilize Ni and Cu as alloying elements in PM steels, but the high and fluctuating prices of Ni and the concerns around it associated with health hazards as well as the difficulty in recycling Cu lead the PM industry to search for effective alternatives such as Cr and Mn. LÄS MER

  7. 5. Gear tribology : friction and surface topography

    Författare :Li Xiao; Bengt-Göran Rosén; Liam Blunt; Högskolan i Halmstad; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Friction; Surface topography; Toughness; Lay; Gears; Power transmission; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The quest for energy efficiency leads to the development of highly efficient power transmissions for vehicles. Gears are some of the most rugged and durable torque transmitters among machine elements. Friction between sliding surfaces at gear teeth is one major source of power loss. LÄS MER