Sökning: "infrared absorption spectroscopy"

Visar resultat 21 - 25 av 133 avhandlingar innehållade orden infrared absorption spectroscopy.

1. 21. Infrared Laser-Induced Grating Techniques for Diagnostics in Reactive Flows

   Författare :Dina Hot; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser diagnostics; infrared; laser-induced grating spectroscopy; degenerate four-wave mixing; flames; temperature; concentration; Fysicumarkivet A:2020:Hot;

   Sammanfattning : AbstractThe work presented in this thesis is mainly focused on the development andapplication of infrared laser-induced grating techniques in order to measure the gasphase temperature and species concentrations in reactive flows. The two techniquesused for this purpose are laser-induced grating spectroscopy (LIGS) and degeneratefour-wave mixing (DFWM). LÄS MER

3. 22. Surface Vibrational and Electron Spectroscopy - Experiments and first-principle calculations

   Författare :Martin Andersson; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gränsskikt; anharmonicity; Ytkemi; Surface and boundary layery chemistry; adsorbates; metal surface; density functional theory; first-principle calculations; electron spectroscopy; reflection-absorption infrared spectroscopy; vibrational spectroscpy;

   Sammanfattning : This work deals with interpretation of experimental surface spectroscopic data with the aid of first-principle calculations. Surface infrared reflection-absorption spectra as well as spectra from the electron spectroscopic methods photoemission and X-ray absorption are considered. LÄS MER

4. 23. Microfabrication of Optical Components in Synthetic Diamond : Infrared Optics for Applications  in Astronomy and Spectroscopy

   Författare :Ernesto Vargas Catalan; Mikael Karlsson; Thomas Schuelke; Uppsala universitet; []
   Nyckelord :Diamond; microfabrication; microoptics; astronomy; IR-spectroscopy; corongraph; waveguide;

   Sammanfattning : Infrared optics is a broad general term, relevant to a range of fields. The manufactured diamond optical components utilized within this thesis were applied to both astronomy, in which direct imaging of star system using large ground-based telescopes and diamond coronagraphs was performed, and in absorption spectroscopy probing solvents and proteins using a tuneable quantum cascade laser and diamond waveguides. LÄS MER

5. 24. Excited States of Carotenoids and Their Functions in Light Harvesting

   Författare :Donatas Zigmantas; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spektroskopi; magnetic and optical properties; Carotenoids; light-harvesting; excited states; excitation energy transfer; femtosecond spectroscopy; supraconductors; magnetic resonance; electrical; Condensed matter:electronic structure; time-resolved fluorescence spectroscopy; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; relaxation; spectroscopy;

   Sammanfattning : The research presented in this thesis is focused on characterization of photophysical properties of lowest singlet excited states of carotenoids and their functions in the process of photosynthetic light harvesting. It is shown that the various light-harvesting complexes utilize different strategies to achieve efficient energy transfer from carotenoids to (bacterio)chlorophylls. LÄS MER

7. 25. Infrared - X-ray pump probe spectroscopy

   Författare :Viviane Costa Felicissimo; Faris Gelmukhanov; KTH; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biochemistry; Biokemi; Biochemistry; Biokemi;

   Sammanfattning : The present thesis concerns theoretical studies of molecular interactions investigated by infrared and X-ray spectroscopic techniques, with emphasis on using the two technologies combined in pump probe experiments. Three main types of studies are addressed: the use of near-edge X-ray absorption fine structure spectra (NEXAFS) to manifest through-bond and through-space interactions; the role of hydrogen bonding on the formation of X-ray photoelectron spectra as evidenced by simulations of the water dimer; and the development of theory, with sample applications, for infrared X-ray pump probe spectroscopy - the main theme of the thesis. LÄS MER