Sökning: "Fluorescence lifetimes"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden Fluorescence lifetimes.

  1. 1. Electronic Energy Transfer within Asymmetric Pairs of Fluorophores: Partial Donor-Donor Energy Migration (PDDEM)

    Författare :Stanislav Kalinin; Lennart B.-Å. Johansson; Helge Lemmetyinen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; fluorescence resonance energy transfer FRET ; donor-donor energy migration DDEM ; homotransfer; fluorescence relaxation; lifetimes; time-resolved fluorescence anisotropy; time-correlated single photon counting; distance measurements; protein structure; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : A kinetic model of electronic energy migration within pairs of photophysically non-identical fluorophores has been developed. The model applies to fluorescent groups that exhibit different photophysical and spectral properties when attached to different positions in a macromolecule. LÄS MER

  3. 2. Temporal Modulation in Fluorescence Spectroscopy and Imaging for Biological Applications

    Författare :Gustav Persson; Jerker Widengren; Jörg Enderlein; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fluorescence; spectroscopy; microscopy; modulated excitation; intensity modulation; fluorescence correlation spectroscopy; transient states; molecular kinetics; Physics; Fysik;

    Sammanfattning : This thesis explores the benefits of intensity modulation for the purpose of extending the range of applications of fluorescence spectroscopy and imaging in cellular and molecular biology and medicine. Long-lived transient states of fluorescent molecules can, because of their long lifetimes, be used to detect subtle changes in the microenvironment of the molecule. LÄS MER

  4. 3. Short-Pulse Laser Spectroscopy for Combustion Diagnostics - Laser-Induced Fluorescence of Polyatomic Molecules and Developments in Measurement and Evaluation

    Författare :Thomas Metz; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pulsed lasers; Physics; Fysik; Laser technology; Laserteknik; non-linear spectroscopy; maximum likelihood; curve fitting; data adjustment; statistical inference; formaldehyde; PAH; polycyclic aromatic hydrocarbons; lifetime imaging; two-dimensional; streak camera; LIF; laser-induced fluorescence; Fluorescence lifetimes; time-resolved;

    Sammanfattning : Combustion is the most important source of energy worldwide. A better understanding of it is essential if pollutant emissions are to be reduced and combustion devices be made more efficient. This requires measurement of physical and chemical combustion parameters. LÄS MER

  5. 4. Time-Varying Excitation in Fluorescence Spectroscopy for Biological Applications

    Författare :Gustav Persson; Jerker Widengren; Måns Ehrenberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fluorescence; spectroscopy; molecular kinetics; Physics; Fysik;

    Sammanfattning : The focus of this thesis is to explore and use the benefits of time-varying excitation in fluorescence spectroscopy for studies of biomolecular dynamics. Two new techniques taking advantage of modulated excitation are presented. LÄS MER

  7. 5. Laser Diagnostics in Combustion - Elastic Scattering and Picosecond Laser-Induced Fluorescence

    Författare :Frederik Ossler; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spray; Picosecond laser; Streak camera; Time resolved; Fluorescence lifetimes; 3 – D flow imaging; 2 - D lifetime imaging; Pressure; Temperature; Hydrogen atoms; Oxygen atoms; 3-pentanone; Acetone; Lorenz-Mie theory; Aerosol; Fysicumarkivet A:1999:Ossler; Scattering; Fysik; Physics; Polycyclic aromatic hydrocarbons.;

    Sammanfattning : Elastic scattering and the Lorenz-Mie (LM) theory in particular is used for the characterization of sub-micron- and micron-sized droplets of organic fuels in sprays and aerosols. Calculations on the Lorenz- Mie theory show that backward-sideward scattered visible radiation can be used for unambiguous detection of ensembles of homogeneous droplets of organic substances with diameters around 1 micrometer (size parameter between 2 and 6). LÄS MER