Sökning: "Thermal modification"

Visar resultat 11 - 15 av 114 avhandlingar innehållade orden Thermal modification.

  1. 11. Birch xylan modification by lactide grafting

    Författare :Johanna Persson; Ann-Christine Albertsson; Monica Ek; Mikael Lindström; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The wood based biorefinery concept has led to an increasing interest in the possibility of using hemicelluloses as a source for value added products. Hemicelluloses are dissolved in large amounts in the process liquor during kraft pulping. LÄS MER

  3. 12. On the impact of temperature perturbations on the creep of sensitive clay

    Författare :Yanling Li; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; thermal cycles; sensitive clays; oedometer tests; temperature; natural bonding; apparent preconsolidation pressure; multi-physics modelling; geothermal; static thermal loading;

    Sammanfattning : Temperature affects the soil response, but is not fully understood and quantified and thus often ignored. The temperature fluctuations resulting from energy foundations and construction activities, such as excavations and soil stabilization, however, may lead to changes in the hydromechanical response of the clay. LÄS MER

  4. 13. Proton-Conducting Sulfonated and Phosphonated Polymers and Fuel Cell Membranes by Chemical Modification of Polysulfones

    Författare :Benoit Lafitte; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Macromolecular chemistry; Makromolekylär kemi; Material technology; Materiallära; materialteknik; chemical modification; lithiation; fuel cells; polyelectrolyte; sulfonated polymers; proton-conducting polymer membranes polysulfone; phosphonated polymers;

    Sammanfattning : The proton exchange membrane fuel cell (PEMFC) is currently emerging as an efficient and environmentally friendly power source. The technology is very complex and relies ultimately on materials and components which need further development. LÄS MER

  5. 14. Cellulose-fiber-based thermal insulation materials with fungal resistance, improved water resistance and reaction-to-fire properties

    Författare :Chao Zheng; Monica Ek; Dongfang Li; Lars Wågberg; Folke Björk; KTH; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biorefinery; birch bark; cellulose; reaction-to-fire properties; fungal resistance; thermal insulation; water resistance; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Thermal insulation materials made from natural fibrous materials, such as cellulose fibers, have advantages over others from a sustainability point of view. However, cellulosic materials are generally prone to mold and absorb moisture, and these have negative effects on the insulation properties, the durability of insulation materials, and interior air quality. LÄS MER

  7. 15. Secondary Electromagnetic Radiation Generated by HF Pumping of the Ionosphere

    Författare :Lars Norin; Bo Thidé; Savely M. Grach; Bengt Gustafsson; James W. LaBelle; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; space physics; ionospheric modification experiments; plasma turbulence; stimulated electromagnetic emission; ionospheric irregularities; radio waves; parametric processes; thermal parametric instability; transient dynamics; wave-wave interactions; Physics; Fysik;

    Sammanfattning : Electromagnetic waves can be used to transmit information over long distances and are therefore often employed for communication purposes. The electromagnetic waves are reflected off material objects on their paths and interact with the medium through which they propagate. LÄS MER