Sökning: "Laser-based"

Visar resultat 1 - 5 av 113 avhandlingar innehållade ordet Laser-based.

  1. 1. Laser-based absorption spectrometry : development of NICE-OHMS towards ultra-sensitive trace species detection

    Författare :Florian Schmidt; Ove Axner; Livio Gianfrani; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; trace species detection; fiber laser; modulation; cavity-enhanced spectroscopy; optical saturation; laser frequency stabilization; free-spectral-range; Physics; Fysik;

    Sammanfattning : Laser-based absorption spectroscopy (AS) is a powerful technique for qualitative and quantitative studies of atoms and molecules. An important field of use of AS is the detection of species in trace concentrations, which has applications not only in physics and chemistry but also in biology and medicine, encompassing environmental monitoring, regulation of industrial processes and breath analysis. LÄS MER

  3. 2. Laser-Based Techniques for Combustion Diagnostics

    Författare :Nikola Georgiev; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; LIF; Laser-based diagnostic techniques; PS; DFWM; Fysik; Fysicumarkivet A:1997:Georgiev;

    Sammanfattning : Two-photon-induced Degenerate Four-Wave Mixing, DFWM, was applied for the first time to the detection of CO, and NH3 molecules. Measurements were performed in a cell, and in atmospheric-pressure flames. In the cell measurements, the signal dependence on the pressure and on the laser beam intensity was studied. LÄS MER

  4. 3. Applications of Laser Based Measurements to Combustion Related Fluid Dynamics

    Författare :Jens Klingmann; Kraftverksteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; applied thermodynamics; Thermal engineering; flame speed.; combustion; turbulence; Laser based measurements; laser Doppler anemometry; Termisk teknik; termodynamik;

    Sammanfattning : This thesis is concerned with laser based techniques for the measurement of fluid dynamical properties and their application to combusting flowfields or flowfields related to combustion. As an introduction, the theory of turbulent flows and combustion is shortly presented. An overview of laser based measuring techniques is given. LÄS MER

  5. 4. Phenomena in laser based material deposition

    Författare :Himani Naesstroem; Frank Brückner; Alexander Kaplan; Prashanth Konda Gokuldoss; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Produktionsutveckling; Manufacturing Systems Engineering;

    Sammanfattning : This thesis is regarding the use of a laser beam to deposit material. Phenomena in two processes, laser beam welding with filler wire and blown powder directed energy deposition (DED) also known as laser metal deposition (LMD)1, are discussed. LÄS MER

  7. 5. Laser-Based Investigations of Combustion Phenomena in Gas Turbine Related Burners

    Författare :Arman Subash; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Combustion; Gas turbine; Chemiluminescence; laser-based techniques; LIF; PIV; DLE; TARS; CH4; H2; OH; CH20; Equivalence ratio; flame stabilization; LBO; Flashback; RPL; Fysicumarkivet A:2018:Subash;

    Sammanfattning : Experiments were performed on various combustion devices to investigate the flames employing different optical measurement techniques under atmospheric pressure conditions. Non-intrusive laser-based techniques provided in-situ information concerning different parameters of the combustion process, with a high degree of temporal and spatial resolution. LÄS MER