Sökning: "fractionation"

Visar resultat 1 - 5 av 235 avhandlingar innehållade ordet fractionation.

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

    Detta är en avhandling från Stockholm : KTH

    Författare :Jonas Bergström; Bo Norman; Mark Martinex; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre suspension; fractionation; hydrocyclone; measurement technique; velocity measurement; shear forces; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik 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

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

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Nathalie Pérez Rodríguez; [2012]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cu and Fe isotopes; fractionation; tailings; plants; phytoremediation; organic amendments; soil bacteria; Cu and Fe cycle; covellite; redox processes; Earth sciences - Exogenous eart sciences; Geovetenskap - Exogen geovetenskap; 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

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

    Detta är en avhandling från Stockholm : Department of Physics, Stockholm University

    Författare :Emely Lindblom; Iuliana Toma-Dasu; Ingmar Lax; Ludvig Paul Muren; [2014]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hypoxia; Reoxygenation; SBRT; Fractionation; medicinsk strålningsfysik; Medical Radiation Physics;

    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

  4. 4. Radiobiological end-points for the theoretical evaluation of the effectiveness of carbon ions and photons in treating tumours with dynamic hypoxia

    Detta är en avhandling från Stockholm : Department of Physics, Stockholm University

    Författare :Antonovic Laura; Iuliana Toma-Dasu; Tatsuaki Kanai; [2014]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; OER; hypoxia; LOC; RCR; hypofractionation; SBRT; carbon ion; fractionation; TCP; SF; RCE; RBE; medicinsk strålningsfysik; Medical Radiation Physics;

    Sammanfattning : Tumours are characterised by unorganised vasculature, which often results in hypoxic regions. Hypoxia is a common cause for photon radiotherapy (RT) treatment failure, as hypoxic cells require up to 2-3 times higher doses compared to well-oxygenated cells for the same effect in terms of cell kill. LÄS MER

  5. 5. Alternative methods for analysing moisture transport in buildings Utilisation of tracer gas and natural stable isotopes

    Detta är en avhandling från Stockholm : KTH

    Författare :Kjartan Gudmundsson; [2003]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tracer gas; water vapour permeability; diffusion; surface diffusion; isotopic analysis; deuterium; oxygen-18; fractionation; vapour barrier; transient numerical modelling of diffusion; TECHNOLOGY Civil engineering and architecture Building engineering; TEKNIKVETENSKAP Samhällsbyggnadsteknik och arkitektur Byggnadsteknik;

    Sammanfattning : New methods, based on tracer gas measurements and isotopicanalysis can be used to evaluate the moisture properties ofbuilding materials and provide the means for forensic analysisof the origins and history of excessive water in buildings, theimmediate practical consequences of which will be the abilityto improve the moisture performance of constructions.It is shown, in theory and through measurements how thewater vapour permeability of porous building materials can witha good degree of accuracy be estimated with tracer gasmeasurements that provide an efficient alternative to the cupmethod. LÄS MER