Sökning: "IR spectroscopy"

Visar resultat 21 - 25 av 147 avhandlingar innehållade orden IR spectroscopy.

1. 21. Cellulose-water interaction: a spectroscopic study

   Författare :Erik L Lindh; István Furó; Lennart Salmén; Lisbeth G Thygesen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cellulose; water; hydrogen exchange; deuterium; NMR spectroscopy; FT-IR spectroscopy; Kemi; Chemistry;

   Sammanfattning : The human society of today has a significantly negative impact on the environment and needs to change its way of living towards a more sustainable path if to continue to live on a healthy planet. One path is believed to be an increased usage of naturally degradable and renewable raw materials and, therefore, attention has been focused on the highly abundant biopolymer cellulose. LÄS MER

3. 22. Shining Light on Molecules : Electron Transfer Processes in Model Systems for Solar Energy Conversion Investigated by Transient Absorption Spectroscopy

   Författare :Jens Föhlinger; Leif Hammarström; Davidsson Jan; Benjamin Dietzek; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photophysics; photoinduced electron transfer; transient absorption spectroscopy; laser spectroscopy; solar energy conversion; p-type DSSCs; Charge separation; recombination; mesoporous NiO;

   Sammanfattning : In the recent years, solar energy conversion has attracted a huge research interest due to the potential application for limiting the greenhouse effect. In many solar cells and solar fuel cells, understanding of charge transfer (CT) and recombination is important for future improvement of the overall efficiency. LÄS MER

4. 23. Development and Application of Non-linear Mid-infrared Laser Spectroscopy for Combustion Diagnostics

   Författare :Zhiwei Sun; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Degenerate four-wave mixing; Polarization spectroscopy; Mid-infrared; Non-linear laser spectroscopy; Laser diagnostics; Combustion; Flame; HITRAN; Concentration; Temperature; Fysicumarkivet A:2012:Sun;

   Sammanfattning : The work reported in this thesis involved the development and application of two novel infrared non-linear laser techniques, namely mid-infrared polarization spectroscopy (IRPS) and mid-infrared degenerate four-wave mixing (IR-DFWM) to combustion diagnostics. These two techniques meet the needs of species concentration detection in combustion environments, especially for those species lacking accessible electronic (one-photon) transitions in the ultraviolet (UV) or visible spectral region. LÄS MER

5. 24. Time-Resolved Attosecond Spectroscopy of He Using COLTRIMS

   Författare :Predrag Ranitovic; Reinhold Schuch; C. L. Cocke; Robert Moshammer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; attosecond spectroscopy; Physics; Fysik; Physics; fysik;

   Sammanfattning : Tunable ultrafast lasers are becoming a standard tool for probing and controlling the dynamics of atoms, molecules and chemical reactions. This thesis is a contribution to a large, ongoing effort to make spectroscopic tools for inducing and controlling, in real time, the natural processes which occur on the femto and attosecond times scales. LÄS MER

7. 25. X-ray Spectroscopy of Molecules Driven by Strong IR Fields

   Författare :Freddy Fernandes Guimaraes; Faris Gelmukhanov; Michael Meyer; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : The current thesis deals with one important branch of the physics of ultrafast processes, namely modeling of femtosecond nuclear dynamics. We suggest a new type of time resolved spectroscopy, the phase sensitive infrared-x-ray pump probe spectroscopy, which combines rich opportunities of IR laser techniques in quantum control of molecular systems with the site selectivity of x-rays. LÄS MER