Sökning: "laser attenuation"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden laser attenuation.

  1. 1. Laser Sheet Imaging and Image Analysis for Combustion Research

    Författare :Rafeef Abu-Gharbieh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-linear diffusion filtering; optically dense sprays; curve evolution propagation; image sequence analysis; laser induced fluorescence; geodesic paths; level sets; LIF; optical density; spray characterization; flame propagation; laser; particle image velocimetry; spectroscopy; combustion engines; spray diagnostics; Mie scattering; flame fronts; laser attenuation; tracking; combustion diagnostics; curve matching; combustion; laser sheet imaging; PIV; time resolved imaging; segmentation;

    Sammanfattning : This Thesis presents techniques that aim at exploiting the potential of image analysis and processing in order to solve problems of data reduction, interpolation, quantification, and interpretation within the field of experimental laser imaging of combustion processes. Combustion is the most important source of energy for power generation, heating, and transportation in the world today and its strong dominance is projected to continue in the foreseeable future. LÄS MER

  3. 2. Pulsed laser ablation studied using digital holography

    Författare :Eynas Amer; Bill O’Neill; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimental Mechanics; Experimentell mekanik;

    Sammanfattning : Pulsed digital holographic interferometry has been used to study the plume and the shock wave generated in the laser ablation process on different targets under atmospheric air pressure. A pulsed Nd-YAG laser system (pulse duration 12 ns) has been used both for ablating the material (wavelength 1064 nm) and for measurement (wavelength 532 nm). LÄS MER

  4. 3. Multi-Dimensional Quantitative Laser-based Diagnostics - Development and Practial Applications

    Författare :Rikard Wellander; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Post injection; Structured illumination; Mie scattering; Dense sprays; Extinction coefficient; Signal attenuation; Laser extinction; Multiple scattering; Scattering measurements; Planar laser induced fluorescence; Time resolved; Imaging through turbulent media; Three-dimensional image acquisition; Diesel particulate filter regeneration; Wall impingent; Biodiesel; LII; Large-bore gas Engine; Pre-chamber ignition; Fysicumarkivet A:2014:Wellander;

    Sammanfattning : Laser based optical diagnostic methods are routinely used in combustion research. Many of the more common approaches are based on illuminating a cross-section of the sample with a thin laser sheet. For example, by targeting an electronic transition in a molecule, its concentration within the plane illuminated by the laser sheet can be deduced. LÄS MER

  5. 4. Structured Laser Illumination Planar Imaging SLIPI Applications for Spray Diagnostics

    Författare :Elias Kristensson; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; signal attenuation; Multiple light scattering suppression; laser extinction; extinction coefficient; structured illumination; Fysicumarkivet A:2012:Kristensson;

    Sammanfattning : Laser sheet imaging, also known as planar laser imaging, is one of the most versatile optical imaging techniques known and is frequently applied in several different domains. It furthermore constitutes the basis for a variety of other 2D methods, in turn allowing visualization of e.g. velocity, particle size, species concentration and temperature. LÄS MER

  7. 5. 1060 nm GaAs VCSELs for Extended Reach Optical Interconnects in Data Centers

    Författare :Ewa Simpanen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-speed modulation; reach; vertical-cavity surface-emitting laser; multi-mode; single-mode; optical interconnect; chromatic dispersion; attenuation;

    Sammanfattning : The data centers of today are increasing in size and are built to accommodate strong data traffic demands while providing sustainably by having clients sharing resources under one roof. Their massive scale puts pressure on the server network topology and has incited a need for data transmission links that are energy efficient and capable to operate at high bit rates with reach up to a few kilometers. LÄS MER