Sökning: "gas exchange"

Visar resultat 31 - 35 av 283 avhandlingar innehållade orden gas exchange.

  1. 31. Carbon gas biogeochemistry of a northern peatland - in a dynamic permafrost landscape

    Författare :Kristina Bäckstrand; Patrick M. Crill; Torben R. Christensen; David Bastviken; Kimberly P. Wickland; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon balance; Carbon exchange; Peatland; Subarctic; Climate change; Earth sciences; Geovetenskap; geokemi; Geochemistry;

    Sammanfattning : This thesis is about biogeochemical processes of a northern peatland and their importance as a link between the climate and the terrestrial system. Increased temperatures on a global level, and particularly in the Arctic, have led to melting permafrost and changes in hydrology. LÄS MER

  3. 32. Lung aeration and pulmonary gas exchange during general and epidural anaesthesia : Influenced by inspired oxygen concentration and diaphragm shape

    Författare :Adrian Reber; Uppsala universitet; []
    Nyckelord :Medical sciences; Anesthesia: epidural; MEDICIN OCH VÅRD; MEDICINE; MEDICIN; Clinical Physiology; klinisk fysiologi;

    Sammanfattning : Induction of general anaesthesia causes a rapid decrease in functional residual capacity, which can promote alveolar collapse (atelectasis) and airway closure in dependent lung regions. Mismatching of ventilation and perfusion (VA/Q) in the lungs is accompanied by impairment of pulmonary gas exchange. LÄS MER

  4. 33. Investigations of proton conducting polymers and gas diffusion electrodes in the polymer electrolyte fuel cell

    Författare :Peter Gode; Göran Lindbergh; Steven Holdcraft; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; polymer electrolyte fuel cell; proton conducting membrane; porous electrode; gas permeability; degradation; water transport; Teoretisk kemi; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : Polymer electrolyte fuel cells (PEFC) convert the chemically bound energy in a fuel, e.g. hydrogen, directly into electricity by an electrochemical process. Examples of future applications are energy conversion such as combined heat and power generation (CHP), zero emission vehicles (ZEV) and consumer electronics. LÄS MER

  5. 34. Nanoparticles based molecular electronic devices with tunable molecular functionalization shell and gas sensing measurements

    Författare :Omer Sher; Klaus Leifer; Khaled Saoud; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Molecular electronics; gas sensor; hybrid devices; gold nanoparticles; organic molecules; secondary molecular functionalization process;

    Sammanfattning : The idea to use molecules as a basic building block in electronic circuits was developed about 50 years ago when a molecular rectifier was developed, but it has been a challenge for this field to make its way to real-world application. Now, due to the advancement in technologies, the properties of single molecules are better understandable and controllable. LÄS MER

  7. 35. Air-sea exchange of O2 and CO2 : Processes controlling the transfer efficiency

    Författare :Andreas Andersson; Anna Rutgersson; Brian Ward; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; air-sea flux; oxygen; transfer velocity; water-side convection; Arctic; UVCN; Meteorologi; Meteorology;

    Sammanfattning : World oceans cover more than 70% of the earth surface and constitutes a major sink of atmospheric CO2. Two of the most important gases in the marine carbon cycling are O2 and CO2 and hence accurate descriptions of the air-sea gas exchange of these gases are crucial. LÄS MER