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Visar resultat 1 - 5 av 18 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Optics of coated paperboard : Aspects of surface treatment on porous structures

    Författare :Erik Bohlin; Caisa Johansson; Magnus Lestelius; Per Edström; Per-Åke Johansson; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Engineering; Kemiteknik;

    Sammanfattning : Calendering of coated and uncoated paper is widely used to enhance optical properties such as gloss and print quality. The aim of this thesis is to characterize coatings and prints, and to validate models using experimental results from optical measurements of physical samples. Calendering of coated paper often leads to a brightness decrease. LÄS MER

  3. 2. Mathematical modeling and numerical tools for simulation and design of light scattering in paper and print

    Författare :Per Edström; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mathematical modeling; radiative transfer; integro-differential equations; inverse problems; parameter estimation; solution method; numerical performance; light scattering; paper industry applications; Kubelka-Munk; MATHEMATICS; MATEMATIK;

    Sammanfattning : This work starts with a real industrial problem - the perceived need for a moredetailed and more accurate model for light scattering in paper and print than theKubelka‐Munk model of today. A careful analysis transfers this problem into aphysical description of the phenomena involved. LÄS MER

  4. 3. Mathematical Modelling of Light Scattering in Paper and Print

    Författare :Per Edström; Mårten Gulliksson; Inge Söderkvist; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mathematical modeling; radiative transfer; solution method; numerical stability; speed; light scattering; light absorption; Kubelka-Munk; errors; reflectance calculations; MATHEMATICS; MATEMATIK;

    Sammanfattning : A problem formulation and a solution method are outlined for the radiative transfer problem in vertically inhomogeneous scattering and absorbing media, using discrete ordinate model geometry. The treatment spans from the physical problem via a continuous formulation, a discretization and a numerical analysis, to an implementation with performance evaluation and application to real-world problems. LÄS MER

  5. 4. Measuring and modelling light scattering in paper

    Författare :Niklas Johansson; Per Edström; Mattias Andersson; Magnus Neuman; Jon Yngve Hardeberg; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; goniophotometry; anisotropy; angle resolved light scattering; reflectance measurements; turbid media;

    Sammanfattning : Avhandlingen behandlar de teoretiska och praktiska aspekterna av att använda spektrala vinkelupplösta reflektansmätningar för optisk karakterisering av fiberbaserade material såsom papper och kartong. En spektral goniofotometer används för att mäta det reflekterade ljusets vinkelfördelning. LÄS MER

  7. 5. Surface and porous structure of pigment coatings : Interactions with flexographic ink and effects on print quality

    Författare :Erik Bohlin; Caisa Johansson; Per Edström; Göran Ström; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Coating; Pigment; Calendering; Porosity; Flexographic Printing; Print quality; Chemical Engineering; Kemiteknik;

    Sammanfattning : Each day, we are confronted with a large amount of more or less important information that we have to consider, and even in our digital society we need paper for communication, documentation and education. Much of the paper we use or are confronted by in our daily life, such as newspapers, books and packages, contains printed images or texts, and the appearance of both the print and the supporting surface is important. LÄS MER