Sökning: "diffraction and scattering"

Visar resultat 11 - 15 av 121 avhandlingar innehållade orden diffraction and scattering.

1. 11. Direct imaging of Stimulated Raman scattering : 3D spatial control and spatial generation

   Författare :Ronja Eriksson; Kerstin Ramser; Mikael Sjödahl; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Experimental Mechanics; Experimentell mekanik;

   Sammanfattning : Stimulated Raman scattering (SRS) is a powerful imaging technique that has become popular during the last decades for its ability to image species specific in a sample with high accuracy. The purpose of this thesis is twofold. Firstly, to demonstrate 3D spatial control of where in the sample SRS is generated. LÄS MER

3. 12. Elastic Wave Scattering by Cracks - Interfacial Forces and High Frequency Diffraction

   Författare :Gert Persson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic testing; Wiener-Hopf calculations; Geometrical Theory of Diffraction; edge diffracted body waves; PEDGE; two-dimensional diffraction; geometrical elastodynamic waves;

   Sammanfattning : This thesis treats elastic wave scattering by cracks with interfacial forces. The results are of practical interest in ultrasonic testing and includes development of numerical methods used to predict such testing. First the canonical problem of two-dimensional (2-D) diffraction from a semi-infinite crack is solved. LÄS MER

4. 13. Ordered arrays of low-dimensional Au and Pd : synthesis and in situ observations

   Författare :Giuseppe Abbondanza; NanoLund: Centre for Nanoscience; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; nanowires NWs ; nanorods; nanoparticles; Au; Pd; Al; Al2O3; anodization; nano-porous anodic aluminum oxide; powder diffraction; x-ray diffraction; x-ray scattering; SAXS; WAXS; grazing-incidence; two-dimensional surface optical reflectance;

   Sammanfattning : Electrodeposition of metals in templates of nano-porous anodic aluminum oxide (NP-AAO) is a versatile way of fabricating ordered arrays of metal nanowires. Thanks to the self-arranged long-range hexagonal order of the pores, electrodeposition in NP-AAO is an easily scalable bottom-up synthesis route and an attractive alternative to traditional top-down fabrication methods such as electron beam lithography. LÄS MER

5. 14. Picosecond X-ray Diffraction Studies of Bulk and Nanostructure Materials

   Författare :Andrius Jurgilaitis; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solid-liquid transitions; X-ray diffraction and scattering; nanowires; laser beam impact phenomena; phonons in crystal lattices; Fysicumarkivet A:2012:Jurgilaitis;

   Sammanfattning : Fast phenomena occurring after laser excitation were studied using time-resolved X-ray diffraction (TXRD). In most experiments, a femtosecond laser pulse was used to excite the sample, and X-rays were used as a probe. LÄS MER

7. 15. Carbides in martensitic medium carbon low alloyed tool steels studied with small angle scattering techniques, electron microscopy and atom probe tomography

   Författare :Erik Claesson; Peter Hedström; Hans Magnusson; Erik Offerman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low alloyed tool steel; Martensite; Small angle scattering; Scanning transmission electron microscopy; Energy dispersive x-ray spectroscopy; atom probe tomography; Scanning precession electron diffraction; Precipitation; carbides; Tempering.; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning : Medium carbon low alloyed tool steels are used today in various areas to shape plastics, nonferrous metals, and steels, and they are crucial in the manufacturing industry. To be effective, tool steels must be strong and tough, and have high wear resistance and temperature stability. LÄS MER