Sökning: "Surface Potential"

Visar resultat 1 - 5 av 1917 avhandlingar innehållade orden Surface Potential.

  1. 1. Potential Flow Panel Methods for the Calculation of Free-surface Flows with Lift

    Författare :Carl-Erik Janson; Chalmers University of Technology; []
    Nyckelord :desingularized; shape optimization; Rankine source; waves; OCTOPUS; dipole; MMA; Dawson operator; boundary layer; vortex; Method of Moving Asymptotes; nonlinear; sailing yacht; four point operator; surface piercing wing; Navier-Stokes; numerical method; lift force; raised panel method; discrete Fourier transform; collocation point shift; potential flow; CFD; free surface; induced drag; SHIPFLOW; dispersion; damping; analytical method; hydrofoil;

    Sammanfattning : Two non-linear Rankine-source panel methods are developed and implemented in the same computer code. The first method uses a four-point upwind operator on the free-surface to compute the velocity derivatives and to enforce the radiation condition while the second method uses an analytical expression for the velocity derivatives and a collocation point shift one panel upstream to prevent upstream waves. LÄS MER

  3. 2. Aqueous Processing of WC-Co Powders

    Författare :Karin M. Andersson; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Hard Metal; Cemented Carbide; WC-Co; Tungsten Carbide; Cobalt; Oxidation; Dissolution; Surface Complexation; XPS; AFM; Colloidal Probe; Hamaker Constant; Cauchy; WO3; CoOOH; ESCA; Zeta-Potential; Surface Potential; Poly ethylene imine ; PEI; Suspensi;

    Sammanfattning : The object of this work is to obtain a fundamentalunderstanding of the principal issues concerning the handlingof an aqueous WC-Co powder suspension.The WO3 surface layer on the oxidised tungsten carbidepowder dissolves at pH>3 with the tungsten concentrationincreasing linearly with time. 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 :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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. Localised corrosion and atmospheric corrosion of stainless steels

    Författare :Sukanya Hägg Mameng; Rachel Pettersson; Christopher Leygraf; Thomas Ladwein; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stainless steel; localised corrosion; atmospheric corrosion; alloy composition; surface finish; surface roughness; surface treatment; surface orientation; contamination; chloride; sulphate; temperature; chlorination; exposure conditions.; Kemi; Chemistry;

    Sammanfattning : This research is focused on defining limiting conditions for corrosion of stainless steels. The aim of the first part (Papers I-IV) was to understand the role of alloying level and environmental parameters on localised corrosion in aqueous conditions. LÄS MER

  7. 5. Electrical Charges on Polymeric Insulator Surfaces and their Impact on Flashover Performance

    Författare :Sarath Kumara; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; streamer criterion; polymeric insulation; flashover voltage; surface potential; bulk conductivity; surface conduction; humidity; bulk neutralization; charge decay; Surface charge; silicone rubber; corona charging; gas neutralization;

    Sammanfattning : Utilization of remotely located sustainable energy resources such as solar, wind and hydro calls for further developments of long-distance electric power transmissions operating at ultra-high voltage (UHV) levels which may exceed 1000 kV ac and 800 kV dc utilized today. It is foreseen that insulation of such transmission systems is to be based on polymeric materials that can provide a number of technical benefits over traditionally used glass and porcelain based insulation. LÄS MER