Sökning: "volume fractions"

Visar resultat 1 - 5 av 92 avhandlingar innehållade orden volume fractions.

  1. 1. Macroscopic Volume and Free Volume of Polymer Blends and Pressure-densified Polymers

    Författare :Marcus Schmidt; [2000]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; free-volume theories; refractive index; Lorentz-Lorenz equation; loss tangent; Avrami equation; freezing fractions; copolymers; polymer blends; pressure dilatometry; Tait equation of state; free-volume distributions; pressure-densified polymers; entropy of melting; dynamic-mechanical analysis; positronium; positron annihilation; free volume; cavity size; polymers; bulk modulus; PVT; phase separation; compressibility; thermal expansivity;

    Sammanfattning : The macroscopic volume V as a function of pressure P and temperature T is obtained from PVT measurements. PVT data is sensitive to the state of polymers and changes therein. Moreover, PVT data gives access to the free-volume fraction. LÄS MER

  2. 2. Water diffusion and free volume in hydrophilic polymers

    Detta är en avhandling från Department of Polymer & Materials Chemistry

    Författare :Charlotte Trotzig; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; free volume; self-diffusion; degree of crystallinity; glass transition temperature; tensile storage modulus; surface tension; isotherm; HPMC; PEO; water; triacetin; clay; Macromolecular chemistry; dynamic mechanical analysis; Fysikalisk kemi; differential scanning calorimetry; nuclear magnetic resonance; positron annihilation; Makromolekylär kemi;

    Sammanfattning : During moisture uptake in polymers, the diffusion of the water molecules is believed to occur via unoccupied voids. These voids are called free volume cavities and their sizes are continuously altered when the moisture content in the polymer is enhanced. LÄS MER

  3. 3. Modelling of Mass and Heat Transport in Paper - Evaluation of Mechanisms and Shrinkage

    Detta är en avhandling från Chemical Engineering, Lund University

    Författare :Erik Baggerud; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; solid-based coordinates; paper; porous medium; convection; diffusion; volume fractions; mercury displacement; shrinkage; simulations; convective; hot surface; Modelling; drying; Wood; pulp and paper technology; Pappers- och massateknik;

    Sammanfattning : In this work a one-dimensional model for the mass and heat transport in the thickness direction of paper has been developed. Solid-based coordinates were applied to simplify incorporation of shrinkage. Liquid diffusion, gas convection and vapour and air diffusion were incorporated as mass transport mechansims. LÄS MER

  4. 4. Modeling Phase Transformations and Volume Changes during Cooling of Case Hardening Steels

    Detta är en avhandling från Stockholm : KTH

    Författare :Matilda Tehler; Stefan Jonsson; Åsa Gustafson; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase transformation; volume changes; TECHNOLOGY Materials science Other materials science; TEKNIKVETENSKAP Teknisk materialvetenskap Övrig teknisk materialvetenskap;

    Sammanfattning : Case hardening distortions are a major problem for gear manufacturers. The aim of the current work is to create a simulation model, able to predict how and when case hardening distortions arise. The results presented in this thesis form a basis for such a model.Two case hardening steels, with base carbon contents of 0. LÄS MER

  5. 5. Robust intersection of hexahedral meshes and triangle meshes with applications in finite volume methods

    Detta är en avhandling från Stockholm : KTH

    Författare :Frida Svelander; Göteborgs universitet.; Gothenburg University.; [2016]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; triangle-hex intersection; overlapping triangles; degenerate mesh; volume fraction; area fraction; cut cell; conjugated heat transfer.; degenerate mesh; volume fraction; area fraction; conjugated heat transfer.; cut cell; overlapping triangles;

    Sammanfattning : The topic of this thesis is the intersection of a structured hexahedral grid andone or more triangle meshes. The interest in the problem has arisen in connection with a finite volume method for simulation of conjugated heat transfer. LÄS MER