Sökning: "Diffusion coefficients"

Visar resultat 1 - 5 av 125 avhandlingar innehållade orden Diffusion coefficients.

  1. 1. Diffusion in Bone Tissue

    Författare :Gustav Lindberg; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bone growth; diffusion; stress enhanced; finite element method; steady-state; periosteal membrane; diffusion in bovine bone; diffusion experiment; Conductivity measurement; Fick’s law; Fourier series; Kalman filter; transient solution;

    Sammanfattning : In order to prevent or modify the processes of bone degeneration the modeling and remodeling of bone tissue must be better understood. In this thesis it is assumed that the primary condition leading to bone growth is a change of the chemical environment caused by transport of matter resulting from stress driven diffusion. LÄS MER

  3. 2. On the determination of diffusion coefficients in bone

    Författare :Abdallah Shokry; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kalman filter; Mathematical model; Spatially dependent diffusion; Diffusion in bone; Diffusion coefficient; Conductivity; Elastic modulus; Porous materials;

    Sammanfattning : Diffusion in bone is needed for bone remodeling and bone healing. Understanding the phenomenon is often important for comprehension bone diseases. Mathematical modeling of the diffusion processes is a required prerequisite in the study of this important physical process in living bone tissue. LÄS MER

  4. 3. Hydrogen in nano-sized metals : Diffusion and hysteresis effects

    Författare :Wen Huang; Björgvin Hjörvarsson; Max Wolff; Gavin Walker; Uppsala universitet; []
    Nyckelord :Hydrogen; diffusion; hysteresis; optical technique; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Metal hydrides can be used as hydrogen storage materials for fuel cells and batteries, and as sensors for detecting hydrogen gas. The use of metal hydrides for hydrogen storage can be hindered by poor kinetics and low capacity. Moreover, poor sensitivity, long recovery and response time, limit the applications of metal hydrides as hydrogen sensors. LÄS MER

  5. 4. Transport Coefficients during Drying of Solids containing Multicomponent Mixtures

    Författare :Rafael Gamero; Joaquín Martínez; Evangelos Tsotsas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; capillary; conduction; convection; diffusion; evaporation; heat transfer; hydraulic conductivity; liquid film; liquid transport; mass transfer; Maxwell-Stefan diffusion coefficients; molar fluxes; phase equilibrium; temperature gradient; ternary mixture; thermodynamic factors; Chemical engineering; Kemiteknik;

    Sammanfattning : This study investigated the transport coefficients involved in mass and heat transfer during the drying of a porous solid partially saturated with multicomponent mixtures.  It included the coefficients governing liquid transport through the solid, the matrix of multicomponent diffusion coefficients in the liquid phase, and the effective thermal conductivity. LÄS MER

  7. 5. Theory of Hydrogen Quantum Diffusion

    Författare :Thomas Mattsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; path-integrals; isotope effect; transition state theory; quantum; diffusion; hydrogen; first-principles calculations; nickel;

    Sammanfattning : Atomic hydrogen adsorbed on a metal surface is one of the simplest possible examples of chemisorption, yet it is very challenging. The adsorption and the very elementary process of surface diffusion, a single atomic jump, have been investigated theoretically using several methods. LÄS MER