Search for dissertations about: "concentration o3"

Showing result 16 - 20 of 21 swedish dissertations containing the words concentration o3.

  2. 16. Origin of volcanic sulfur in Iceland : a sulfur isotope study

    Author : Peter Torssander; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The chemistry and sulfur isotope composition have been determined in fresh and altered rocks and geothermal fluids in Iceland. Sulfur isotope ratios were analysed in 27 selected volcanic rocks, eight lava incrustations and three volcanic gas samples.The 63% of the basalts ranges from -2.0 o/oo to + 0. READ MORE

  4. 17. Neutron scattering for sustainable energy materials: investigations of proton dynamics in acceptor doped barium zirconates

    Author : Daria Noferini; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; neutron scattering; fuel cells; QENS; Proton conductors; perovskites; proton dynamics; energy materials;

    Abstract : Proton conducting oxides are currently receiving considerable attention for their present or potential use as electrolytes in technological devices such as sensors and electrolysers and, in particular, solid oxide fuel cells, which are among the most promising apparatuses for energy conversion. One of the main challenges for these latter devices is to combine the advantages of a solid electrolyte with those of operational temperatures below 750 °C, which is currently hampered by insufficient conductivities in the targeted temperature range. READ MORE

  5. 18. Experimental study of alkalinisation of cellulose in industrial relevant conditions

    Author : Diana Carolina Reyes Forsberg; Ola Sundman; Bertil Eliasson; Ulf Germgård; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Mercerisation; Alkalinisation; Cellulose I; Cellulose II; Alkali cellulose; Viscose; Cellulose ether; Carboxymethylcellulose; Sodium glycolate; Sodium diglycolate; Raman spectroscopy;

    Abstract : Mercerisation of cellulose pulp with a solution of NaOH is the first step of manufacturing cellulose-based value-added products, e.g. viscose fibres and cellulose ethers. During this process, cellulose transforms into a swollen crystalline structure, alkali cellulose (Na-Cell). READ MORE

  6. 19. Modelling the middle atmosphere and its sensitivity to climate change

    Author : Andreas Jonsson; Jörg Gumbel; Joanna Haigh; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; climate change; middle atmosphere; ozone; carbon dioxide; stratosphere; mesosphere; chemical kinetics; atmospheric tides; Meteorology; Meteorologi;

    Abstract : The Earth's middle atmosphere at about 10-100 km has shown a substantial sensitivity to human activities. First, the ozone layer has been reduced since the the early 1980s due to man-made emissions of halogenated hydrocarbons. READ MORE

  7. 20. Physical and Chemical Processes in the Formation of Biogenic secondary Organic Aerosols

    Author : Åsa M. Jonsson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Tropospheric chemistry; monoterpenes; ozonolysis; secondary organic aerosol SOA ; G-FROST; AIDA; humidity; temperature; hydroxyl radicals; volatility; pinonaldehyde; climate and health;

    Abstract : Vegetation emits a vast number of biogenic volatile organic compounds (BVOC). In the atmosphere they are oxidised, predominantly by O3, OH radicals or NO3 radicals, depending e.g. on chemical structure. READ MORE