Sökning: "fractionation"

Visar resultat 1 - 5 av 286 avhandlingar innehållade ordet fractionation.

  1. 1. Flow Field and Fibre Fractionation Studies in Hydrocyclones

    Författare :Jonas Bergström; Bo Norman; Mark Martinex; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre suspension; fractionation; hydrocyclone; measurement technique; velocity measurement; shear forces; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : Hydrocyclones can be used to fractionate fibres according to their papermaking potential. The obtained fractions typically differ in fibre wall thickness and/or degree of fibre treatment. Despite a multitude of potential application scenarios, the process has so far had little commercial success. LÄS MER

  3. 2. Fractionation of Cu and Fe isotopes in metal-rich mine sites : biotic and abiotic processes

    Författare :Nathalie Pérez Rodríguez; Magnus Land; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cu and Fe isotopes; fractionation; tailings; plants; phytoremediation; organic amendments; soil bacteria; Cu and Fe cycle; covellite; redox processes; Applied Geology; Tillämpad geologi;

    Sammanfattning : After mineral exploitation the residual grinded and milled material, rich in sulphide minerals and heavy metals, is often left exposed to the atmospheric variables. This weathered mine waste material can lead to the formation of acid mine drainage (AMD) which has negative effects to the environment. LÄS MER

  4. 3. Searching for the optimal radiotherapy treatment time, dose and fractionation - the role of hypoxia and reoxygenation : A modelling study

    Författare :Emely Lindblom; Iuliana Toma-Dasu; Ingmar Lax; Ludvig Paul Muren; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hypoxia; Reoxygenation; SBRT; Fractionation; Medical Radiation Physics; medicinsk strålningsfysik;

    Sammanfattning : The search for the optimal choice of treatment time, dose and fractionation regimen is one of the major challenges in radiation therapy. Several aspects of the radiation response of tumours and normal tissues give different indications of how the parameters defining a fractionation schedule should be altered relative to each other which often results in contradictory conclusions. LÄS MER

  5. 4. Farm to furan derivatives : Fractionation of agricultural residues and transformation of sugars to chemical building blocks

    Författare :Sara Jonsdottir Glaser; Bioteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biorefinery; sugar beet pulp; wheat bran; agricultural residue; biomass valorisation; fractionation; bio-based platform chemicals; HMF; levulinic acid; heterogeneous catalysis; whole-cell catalysis;

    Sammanfattning : The transition of industrial production from petrochemistry to a more sustainable economy requires the use of carbon neutral, renewable feedstock, which does not compete with food and feed supplies – by-products of farming and agro-food industry offer this possibility. With a limited range of low-value applications today coupled with the need for maximal utilisation of resources, the by-products of farming can be repurposed as feedstock for biorefineries. LÄS MER

  7. 5. Fractionation of woody biomass : lignin and suberin in focus

    Författare :Ivan Kumaniaev; Joseph Samec; Claudia Crestini; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lignocellulose; lignin; suberin; biomass; palladium; catalysis; flow chemistry; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis is dedicated to the research of fractionation and valorization of different types of woody biomass. In the first part, oak (Quercus suber) and birch (Betula pendula) barks are considered. Bark is the outer layer of wood and is treated as waste in the current wood processing technologies. LÄS MER