Far-field Coarsening and Mesh Adaptation for Inviscid Flows on Cartesian Grids

2004 ◽  
Author(s):  
Andrea Dadone ◽  
Bernard Grossman
Keyword(s):  
Mesh Adaptation ◽  
Far Field ◽  
Cartesian Grids ◽  
Inviscid Flows

Far field simulation for short transients of compressible inviscid flows

Meccanica ◽  
1988 ◽  
Vol 23 (1) ◽  
pp. 44-50
Author(s):  
Marcello Onofri ◽  
Maurizio Di Giacinto
Keyword(s):  
Far Field ◽  
Inviscid Flows ◽  
Field Simulation

Possible applications of fraunhofer holography in high resolution electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 222-223 ◽  
Author(s):  
N. Bonnet ◽  
M. Troyon ◽  
P. Gallion
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Transfer Function ◽  
Radiation Damage ◽  
High Resolution Electron Microscopy ◽  
Far Field ◽  
Field Region ◽  
Crystalline Materials ◽  
Resolution Electron ◽  
The Ideal

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.

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