Search for dissertations about: "diffraction"

Showing result 6 - 10 of 1031 swedish dissertations containing the word diffraction.

2. 6. Studies of Edge Diffraction and Scattering: Applications to Room Acoustics and Auralization

   Author : Rendell Torres; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diffraction; virtual environments; scattering; diffusion; architectural acoustics; auralization; virtual reality; room acoustics;

   Abstract : This thesis examines ways of including edge diffraction and surface scattering to improve room acoustics auralization, i.e., the binaural replication of an acoustic environment. The approach combines numerical and psychoacoustical studies to discern what level of computational accuracy is necessary to obtain perceptually adequate replication. READ MORE

4. 7. Electromagnetic simulation and design of etched diffraction grating demultiplexers

   Author : Jun Song; Sailing He; Dries Van Thourhout; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; etched diffraction grating; wavelength division multiplexing; passive devices; diffraction grating; planar waveguide devices; DWDM; optical communication.; Photonics; Fotonik;

   Abstract : Among various planar lightwave circuits for multiplexing/demultiplexing in an optical communication system, etched diffraction gratings (EDGs) have shown great potential due to their compactness and high spectral finesse. Conventional numerical methods for grating simulation cannot be used to simulate an EDG demultiplexer of large size (in terms of the wavelength). READ MORE

5. 8. Phase transformation and stability studies of the Zr-H system

   Author : Tuerdi Maimaitiyili; Lars Hallstadius; Malmö högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Zirconium hydride; synchrotron X-ray diffraction; Nuclear materials; phase transformation; in-situ hydrogen charging; hydrogen related degradation; neutron diffraction; powder diffraction; Rietveld analysis; γ-ZrH; hydrogen embrittlement; zirconium hydride; γ-ZrH; synchrotron X-ray diffraction; neutron diffraction; hydrogen charging; in situ phase transformation; hydrogen embrittlement; hydrogen induced degradation;

   Abstract : Zirconium alloys are widely used in the nuclear industry because of their high strength, good corrosion resistance and low neutron absorption cross-section. Zirconium has a strong affinity for hydrogen, however, and if hydrogen concentration builds up, the material will gradually degrade. READ MORE

6. 9. Characterization of crystalline materials by rotation electron diffraction : Phase identification and structure determination

   Author : Yifeng Yun; Xiaodong Zou; Christian W. Lehmann; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; electron microscopy; phase identification; rotation electron diffraction; structure determination; three-dimensional electron diffraction; Inorganic Chemistry; oorganisk kemi;

   Abstract : Electron crystallography is powerful for determination of complex structures. The newly-developed 3D electron diffraction (ED) methods make structure determination from nano- and micron-sized crystals much easier than using other methods, for example X-ray diffraction. READ MORE

7. 10. Studies of Inorganic Layer and Framework Structures Using Time-, Temperature- and Pressure-Resolved Powder Diffraction Techniques

   Author : Anne Krogh Andersen; Rolf Norrestam; Kenny Ståhl; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; inorganic structure; framework structure; x-ray diffraction; synchrotron radiation; powder diffraction; Chemistry; Kemi;

   Abstract : This thesis is concerned with in-situ time-, temperature- and pressure-resolved synchrotron X-ray powder diffraction investigations of a variety of inorganic compounds with twodimensional layer structures and three-dimensional framework structures. In particular, phase stability, reaction kinetics, thermal expansion and compressibility at non-ambient conditions has been studied for 1) Phosphates with composition MIV(HPO4)2·nH2O (MIV = Ti, Zr); 2) Pyrophosphates and pyrovanadates with composition MIVX2O7 (MIV = Ti, Zr and X = P, V); 3) Molybdates with composition ZrMo2O8. READ MORE