A novel material detection algorithm based on 2D GMM-based power density function and image detail addition scheme in dual energy X-ray images

2012 ◽  
Vol 20 (2) ◽  
pp. 213-228 ◽  
Author(s):  
Hossein Pourghassem
Author(s):  
David Cockayne ◽  
David McKenzie

The technique of Electron Reduced Density Function (RDF) analysis has ben developed into a rapid analytical tool for the analysis of small volumes of amorphous or polycrystalline materials. The energy filtered electron diffraction pattern is collected to high scattering angles (currendy to s = 2 sinθ/λ = 6.5 Å-1) by scanning the selected area electron diffraction pattern across the entrance aperture to a GATAN parallel energy loss spectrometer. The diffraction pattern is then converted to a reduced density function, G(r), using mathematical procedures equivalent to those used in X-ray and neutron diffraction studies.Nearest neighbour distances accurate to 0.01 Å are obtained routinely, and bond distortions of molecules can be determined from the ratio of first to second nearest neighbour distances. The accuracy of coordination number determinations from polycrystalline monatomic materials (eg Pt) is high (5%). In amorphous systems (eg carbon, silicon) it is reasonable (10%), but in multi-element systems there are a number of problems to be overcome; to reduce the diffraction pattern to G(r), the approximation must be made that for all elements i,j in the system, fj(s) = Kji fi,(s) where Kji is independent of s.


2017 ◽  
Author(s):  
Khalaf Alshamrani ◽  
Amaka Offiah ◽  
Elzene kruger
Keyword(s):  
Bone Age ◽  

2013 ◽  
Author(s):  
Christine Wohlfahrt-Veje ◽  
Jeanette Tinggaard ◽  
Annette Mouritsen ◽  
Casper Hagen ◽  
Mikkel Grunnet ◽  
...  
Keyword(s):  
Body Fat ◽  
X Ray ◽  

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