Search for dissertations about: "spektroskopi"

Showing result 1 - 5 of 126 swedish dissertations containing the word spektroskopi.

  1. 1. Road surface characterization using near infrared spectroscopy

    Author : Johan Casselgren; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spektroskopi; Väglagsklassificering; Friktion; Väglagskarakterisering; Experimentell mekanik; Experimental Mechanics;

    Abstract : This thesis presents a technology and method for classifying and characterizing different road conditions such as dry asphalt and asphalt covered with water, ice and snow. The method uses light sources of different wavelengths to illuminate the road surface and a detector to measure the reflected light from the road surfaces, dependent on how the surface have absorbed, scattered and polarized the light it is possible to classify the road condition. READ MORE

  2. 2. Continuous-filtering Vernier spectroscopy

    Author : Chuang Lu; Aleksandra Foltynowicz; Ove Axner; Wei Ren; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; spectroscopy; spectrometer; laser; optical frequency comb; optical cavity; NIR; MIR; flame; robust; time resolution; spectrum; fysik; Physics;

    Abstract : Continuous-filtering Vernier spectroscopy (CF-VS) is a laser-based detection technique that combines the broad spectral coverage of an optical frequency comb (OFC) with the enhanced interaction length provided by an optical cavity. The resonances of the cavity filter the OFC to a small group of comb modes that probe the transitions of the species present in the cavity. READ MORE

  3. 3. Formation and Dynamics of Molecular Excitons and their Fingerprints in Nonlinear Optical Spectroscopy

    Author : Pär Kjellberg; Kemisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; supraledare; magnetisk resonans; spektroskopi; Physical chemistry; Fysikalisk kemi; Photochemistry; Fotokemi; Kondenserade materiens egenskaper:elektronstruktur; magnetiska och optiska ; egenskaper elektriska; supraconductors; magnetic resonance; relaxation; spectroscopy; Fysik; Chemistry; Kemi; Condensed matter:electronic structure; electrical; Physics; Redfield relaxation theory ; Inhomogeneous broadening ; Time-dependent density functional theory ; Conjugated polymers ; Three-pulse photon echo ; Molecular excitons ; magnetic and optical properties; Nonlinear spectroscopy ;

    Abstract : An efficient transfer of energy in molecular systems has proven to be of fundamental importance both in nature and industrial applications. The ability of molecules to work together forming collective excitations, so-called excitons, plays a key role in for example the extraordinary fast energy transfer involved in the first steps of photosynthesis. READ MORE

  4. 4. Laboratory and stellar spectroscopy of the complex ions Fe+, Mo+, Th+ and U+

    Author : Hampus Nilsson; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; molybdenum; iron; thorium; uranium.; Atomic and molecular physics; Atom- och molekylärfysik; Astronomy; space research; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi; Condensed matter:electronic structure; electrical; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; magnetic and optical properties; supraconductors; astrophysics; radiative lifetimes; oscillator strengths; term analysis; Fourier transform spectroscopy; branching fractions; Fysicumarkivet A:2002:Nilsson;

    Abstract : The new generation of high resolution astronomical instruments such as the Hubble Space Telescope (HST) or the Very Large Telescope (VLT) has renewed the demand for accurate atomic parameters like wavelengths, oscillator strengths and line profiles accompanied by reliable uncertainty estimates. Fourier transform spectroscopy has proven to be a powerful tool when measuring these parameters. READ MORE

  5. 5. Quantitative Modeling of Gain in Quantum Cascade Lasers under Operational Intensities

    Author : David Winge; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; non-linear response; quantum cascade lasers; modelling; Non-equilibrium Green s functions; Gain clamping; Fysicumarkivet A:2016:Winge; kvantkaskadlaser; terahertz; infrarött; Halvledarfysik; spektroskopi; simulering;

    Abstract : This thesis adresses modeling of quantum cascade lasers using non-equilibrium Green’s functions. Focus lies on the quantitative modeling of the gain when the systems are exposed to strong laser fields, as under realistic opertional conditions. READ MORE