scholarly journals Mapping the coke formation within a zeolite catalyst extrudate in space and time by operando computed X-ray diffraction tomography

Author(s):  
David S. Wragg ◽  
Georgios N. Kalantzopoulos ◽  
Dimitrios K. Pappas ◽  
Irene Pinilla-Herrero ◽  
Daniel Rojo-Gama ◽  
...  
2003 ◽  
Vol 104 ◽  
pp. 27-30 ◽  
Author(s):  
T. Beetz ◽  
C. Jacobsen ◽  
C.-C. Kao ◽  
J. Kirz ◽  
O. Mentes ◽  
...  

Optica ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 733 ◽  
Author(s):  
Zheyuan Zhu ◽  
Ryan A. Ellis ◽  
Shuo Pang

2011 ◽  
Vol 67 (a1) ◽  
pp. C113-C113
Author(s):  
H. Liu ◽  
L. Wang ◽  
Z. Yu ◽  
L. Kong ◽  
J. Zhao ◽  
...  

2019 ◽  
Vol 8 (3) ◽  
pp. 388-399 ◽  
Author(s):  
Jiwoong Kang ◽  
Ning Lu ◽  
Issac Loo ◽  
Nancy Senabulya ◽  
Ashwin J. Shahani

Abstract Direct imaging of three-dimensional microstructure via X-ray diffraction-based techniques gives valuable insight into the crystallographic features that influence materials properties and performance. For instance, X-ray diffraction tomography provides information on grain orientation, position, size, and shape in a bulk specimen. As such techniques become more accessible to researchers, demands are placed on processing the datasets that are inherently “noisy,” multi-dimensional, and multimodal. To fulfill this need, we have developed a one-of-a-kind function package, PolyProc, that is compatible with a range of data shapes, from planar sections to time-evolving and three-dimensional orientation data. Our package comprises functions to import, filter, analyze, and visualize the reconstructed grain maps. To accelerate the computations in our pipeline, we harness computationally efficient approaches: for instance, data alignment is done via genetic optimization; grain tracking through the Hungarian method; and feature-to-feature correlation through k-nearest neighbors algorithm. As a proof-of-concept, we test our approach in characterizing the grain texture, topology, and evolution in a polycrystalline Al–Cu alloy undergoing coarsening.


2020 ◽  
Vol 9 (1) ◽  
pp. 151-151
Author(s):  
Jiwoong Kang ◽  
Ning Lu ◽  
Issac Loo ◽  
Nancy Senabulya ◽  
Ashwin J. Shahani

2016 ◽  
Vol 648 ◽  
pp. 141-149 ◽  
Author(s):  
Pablo del Campo ◽  
Wojciech Andrzej Slawinski ◽  
Reynald Henry ◽  
Marius Westgård Erichsen ◽  
Stian Svelle ◽  
...  

1996 ◽  
Vol 437 ◽  
Author(s):  
D.P. Piotrowski ◽  
S.R. Stock ◽  
A. Guvenilir ◽  
J.D. Haase ◽  
Z.U. Rek

AbstractIn order to understand the macroscopic response of polycrystalline structural materials to loading, it is frequently essential to know the spatial distribution of strain as well as the variation of micro-texture on the scale of 100 μm. The methods must be nondestructive, however, if the three-dimensional evolution of strain is to be studied. This paper describes an approach to high resolution synchrotron x-ray diffraction tomography of polycrystalline materials. Results from model samples of randomly-packed, millimeter-sized pieces of Si wafers and of similarly sized single-crystal Al blocks have been obtained which indicate that polychromatic beams collimated to 30 μm diameter can be used to determine the depth of diffracting volume elements within ± 70 μm. The variation in the two-dimensional distribution of diffracted intensity with changing sample to detector separation is recorded on image storage plates and used to infer the depth of diffracting volume elements.


Author(s):  
Doĝa Gürsoy ◽  
Tekin Biçer ◽  
Jonathan D. Almer ◽  
Raj Kettimuthu ◽  
Stuart R. Stock ◽  
...  

A maximum a posteriori approach is proposed for X-ray diffraction tomography for reconstructing three-dimensional spatial distribution of crystallographic phases and orientations of polycrystalline materials. The approach maximizes the a posteriori density which includes a Poisson log-likelihood and an a priori term that reinforces expected solution properties such as smoothness or local continuity. The reconstruction method is validated with experimental data acquired from a section of the spinous process of a porcine vertebra collected at the 1-ID-C beamline of the Advanced Photon Source, at Argonne National Laboratory. The reconstruction results show significant improvement in the reduction of aliasing and streaking artefacts, and improved robustness to noise and undersampling compared to conventional analytical inversion approaches. The approach has the potential to reduce data acquisition times, and significantly improve beamtime efficiency.


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