Sökning: "diffraction"

Visar resultat 36 - 40 av 359 uppsatser innehållade ordet diffraction.

1. 36. Particle Simulation and Optimization of a Relativistic Magnetron for HPM Applications

   Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Fasta tillståndets elektronik

   Författare :Wilhelm Thunberg; [2022]
   Nyckelord :Relativistic Magnetron; FOI Magnetron; TE11; HPM; High Power Microwaves; Particle in cell; MAgic3d;

   Sammanfattning : A relativistic magnetron (RM) is a high-power microwave (HPM) source. The main objective of the RM is to generate directed electromagnetic pulses with high power, which can be used in e.g. HPM weapons and for electromagnetic compatibility testing. LÄS MER

3. 37. Laser Scattering for Fast Characterization of Cellulose Filaments

   Kandidat-uppsats, KTH/Fiber- och polymerteknologi

   Författare :Alexandra Konstantinidou; Saga Holmström; Susanna Hellberg; [2022]
   Nyckelord :Cellulose nanofibrils; Fibers; Sustainable development; Bio-based material; Characterization; Microscale; Microscopy; Small-angle light scattering; Laser diffraction; Cellulosananofibriller; Fiber; H˚allbar utveckling; Biobaserade material; Karakterisering; Mikroskala; Mikroskopi; Ljusspridning; Laserdiffraktion;

   Sammanfattning : Cellulosananofibriller (CNFs) hör till naturens mest fundamentala byggstenar och förser naturliga material, såsom den yttre cellväggen i trä, med en otrolig styrka och styvhet. Genom att imitera träets arkitektur öppnas möjligheter upp för tillverkning av nya, biobaserade och lättviktiga strukturella material med mekaniska egenskaper som överskrider de för glasfiber, metaller och legeringar. LÄS MER

4. 38. Nanoscale characterisation of model Ni-Mo catalyst active phases

   Uppsats för yrkesexamina på avancerad nivå, Lunds universitet/Centrum för analys och syntes

   Författare :Jonas Elmroth Nordlander; [2022]
   Nyckelord :Ni-Mo catalysts; Hydrodeoxygenation; TEM; PXRD; Materials chemistry; Chemistry;

   Sammanfattning : An important stepping stone in transitioning from a fossil-fuel based transportation system is the production of bio-fuels such as bio-oils. For bio-oils to be commercially viable, catalytic upgrading via hydrodeoxygenation is required, typically using Ni-Mo oxide or sulfide catalysts. LÄS MER

5. 39. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

   Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

   Författare :Lassi Linnala; [2022]
   Nyckelord :femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

   Sammanfattning : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. LÄS MER

7. 40. The Effect of Alternative Tungsten Carbide Grain Size Distribution on Microstructure and Mechanical Properties in Cemented Carbides

   Master-uppsats, KTH/Materialvetenskap

   Författare :Filip Ivarsson; [2022]
   Nyckelord :Cemented Carbides; WC Grain Size Distribution; Mechanical Properties; Microstructure Analysis; Hårdmetall; WC Kornstorleksfördelning; Mekaniska Egenskaper; Mikrostruktur Analys;

   Sammanfattning : In the constant pursuit of better-performing cemented carbides, recent studies suggest that a combination of better hardness and toughness can be obtained by changing its WC grain size distribution. As the area is still rather unexplored, this  thesis  aims  to  broaden  the  knowledge  and  answer  whether mechanical properties can be changed by changing the WC grain size distribution, in the context of mining drill bit inserts. LÄS MER