Sökning: "diffusion modelling"

Visar resultat 1 - 5 av 187 avhandlingar innehållade orden diffusion modelling.

  1. 1. Upflow anaerobic sludge blanket reactor : modelling

    Författare :Raul Rodriguez; Luis Moreno; Olle Wahlberg; Gunno Renman; KTH; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; wastewater; anaerobic treatment; modelling; UASB reactor.; Chemistry; Kemi;

    Sammanfattning : Anaerobic treatment is widely used around the world as a biological stage in both domestic and industrial wastewater-treatment plants. The two principal advantages of anaerobic over aerobic treatment are the production of biogas, which can be used as fuel, and the lower rate of biomass production, which results in lower maintenance costs for the plant. LÄS MER

  3. 2. Failure of thermal barrier coatings under thermal and mechanical fatigue loading : microstructural observations and modelling aspects

    Författare :Håkan Brodin; Anette M. Karlsson; Linköpings universitet; []
    Nyckelord :thermal barrier coating; TBC; delamination; crack initiation; crack propagation; crack growth; oxidation; alumina; spinel; MCrAIY; diffusion; fatigue; modelling; modeling; degradation; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : Industrial and air-borne gas turbine hot components suffer from creep, oxidation, corrosion and microstructural degradation if not shielded from the hot and aggressive combustion gases. Two major strategies commercially available are adopted; film cooling by pressurised air and application of protective coatings. LÄS MER

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

    Författare :Erik Baggerud; Avdelningen för kemiteknik; []
    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

  5. 4. Characterization of the Mechanisms of Drug Release from Polymer-Coated Formulations using Experiments and Modelling

    Författare :Mariagrazia Marucci; Avdelningen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ethyl cellulose; Release mechanism; coating; polymer blend; modelling; ESPI; diffusion; osmotic pumping; SEM; single pellet; CLSM; hydroxypropyl cellulose; multiple-unit release;

    Sammanfattning : The main objectives of the work presented in this thesis were to develop new experimental methods to improve the understanding of the release mechanism from a coated formulation and to develop new mechanistic models to describe the release process for pellets coated with a semi-permeable film. Another aim was to characterize the release mechanism from a formulation coated with films made of a blend of a water-insoluble polymer, ethyl cellulose (EC), and a water-soluble polymer, hydroxypropyl cellulose (HPC). LÄS MER

  7. 5. Modelling of Drug Release from Reservoir and Matrix Formulations - Multiple Unit Dosage Forms and Swelling and Dissolving Matrix Systems

    Författare :Per Borgquist; Avdelningen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swelling; XEDS; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Polymer technology; biopolymers; Polymerteknik; Pharmaceutical and related technologies; Läkemedelsteknik och relaterad teknik; simulation; single pellet; single-unit release; SEM; reservoir system; poly ethylene oxide ; film-coated; matrix; mathematical model; diffusion; pellet shape; controlled release; polymer dissolution; modelling; ethyl cellulose; Coating; multiple-unit release;

    Sammanfattning : In this work, mathematical models have been developed describing drug release from film-coated reservoir systems as well as drug release and polymer dissolution from swelling and dissolving polymer tablets. The model derivation of both systems is based on a mechanistic approach. The model describing drug release from reservoir systems, i.e. LÄS MER