Sökning: "LASER"

Visar resultat 16 - 20 av 1854 avhandlingar innehållade ordet LASER.

1. 16. Conduction laser welding : modelling of melt pool with free surface deformation

   Författare :Josefine Svenungsson; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Conduction laser welding; numerical modelling; Computational Fluid Dynamics; OpenFOAM; free surface deformation; melt pool; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

   Sammanfattning : Laser welding is commonly used in the automotive-, steel- and aerospace industry. It is a highly non-linear and coupled process where the weld geometry is strongly affected by the flow pattern in the melt pool. Experimental observations are challenging since the melt pool and melt flow below the surface are not yet accessible during welding. LÄS MER

3. 17. Nonlinear optical techniques for ultrafast laser diagnostics : Development of femtosecond LIF, LIGS, CARS and backward lasing

   Författare :Maria Ruchkina; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser diagnostics; femtosecond laser; nonlinear interactions; ultrafast spectroscopy; multi-photon excitation; laser-induced fluorescence; rotational coherent anti-Stokes Raman spectroscopy; laser-induced grating spectroscopy; lasing; backward lasing technique; Fysicumarkivet A:2021:Ruchkina;

   Sammanfattning : The thesis work concerns development and application of four versatile nonlinear optical techniques, based on exploiting ultrashort laser pulses, for diagnostic purposes in gases and flames. The four techniques, all laser-based, are two-photon laser-induced fluorescence (TPLIF), hybrid femtosecond/nanosecond (fs/ns) rotational coherent anti-Stokes Raman scattering (fs/ns RCARS), fs-laser-induced grating spectroscopy (fs-LIGS), and backward lasing. LÄS MER

4. 18. Approaches to particle acceleration in intense laser-matter interaction

   Författare :Joel Magnusson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; particle-in-cell; nonlinear dynamics; laser; plasma; laser-matter interaction; particle acceleration;

   Sammanfattning : In the interaction of ultra-intense laser fields with matter, the target is rapidly ionized and a plasma is formed. The ability of a plasma to sustain acceleration gradients, orders of magnitude larger than achievable with conventional accelerators, has led to a great interest in laser-driven plasma-based particle acceleration and radiation generation, with applications in materials science, biology and medicine. LÄS MER

5. 19. By Means of Beams : Laser Patterning and Stability in CIGS Thin Film Photovoltaics

   Författare :Per-Oskar Westin; Marika Edoff; Uwe Zimmermann; Lars Stolt; Friedrich Kessler; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser patterning; laser ablation; laser micro-welding; stability; Cu InGa Se2; CIGS; thin film solar cells; thin film photovoltaics; module technology; solar energy; Electronics; Elektronik; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

   Sammanfattning : Solar irradiation is a vast and plentiful source of energy. The use of photovoltaic (PV) devices to convert solar energy directly to electrical energy is an elegant way of sustainable power generation which can be distributed or in large PV plants based on the need. LÄS MER

7. 20. Phenomena in material addition to laser generated melt pools

   Författare :Himani Siva Prasad; Frank Brueckner; Alexander Kaplan; Sebastian Piegert; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laser metal deposition; additive manufacturing; laser welding; multi-material; high speed imaging; powder incorporation; off-axis wire feed; streak imaging; laser cladding; absorptivity; Produktionsutveckling; Manufacturing Systems Engineering;

   Sammanfattning : .... LÄS MER