Category: Research Highlights

3D Visualization of Textures in Metals and Alloys

In a separate article, we described how one can use the neo-Eulerian orientation representations to create new 3D visualizations of the Rodrigues Fundamental Zones in homochoric, cubochoric, 3D stereographic, Euler and Rodrigues-Frank orientation representations. In the present article, we use these visualization modes to illustrate how one can represent Orientation Distribution Functions as 3D objects. …

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Electron Channeling Pattern Dictionary Indexing Manuscript

One of our recent papers on dictionary indexing of electron channeling patterns (ECPs) was just accepted for publication in Microscopy & Microanalysis.  The original final submitted manuscript can be found HERE. The figure below represents one of the simulated ECPs from Fig. 5 of the manuscript; it is a false color version and will be …

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3D Visualization of neo-Eulerian and other rotation representations

3D visualization of rotations and crystallographic fundamental zones [This page provides Supplementary Material for the following paper: (DOI:10.1107/S1600576717001157) P. G. Callahan, M. Echlin, T. M. Pollock, S. Singh and M. De Graef, “Three-dimensional texture visualization approaches: theoretical analysis and examples”, J. Appl. Cryst. (2017) 50.] 3D rotations are typically represented in terms of 3×3 rotation …

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New Release of EMsoft Package

EMSoft 3.1 Release It is our pleasure to announce the release of the EMsoft 3.1 software package for the dynamical simulation of electron back-scattered diffraction patterns (EBSD), electron channeling patterns (ECP), and electron Kossel patterns (EKP), Dictionary Indexing for EBSD and ECP, along with a series of smaller support programs. This release once again focuses …

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Software for Time Interlaced Model Based Iterative Reconstruction (TIMBIR)

Summary The time-interlaced model-based iterative reconstruction (TIMBIR) [1,2] is a method for 4D time-space reconstruction of data acquired using synchrotron X-ray computed tomography. TIMBIR is a synergistic combination of two innovations. The first innovation, interlaced view sampling, is a novel method of data acquisition which distributes the view angles more evenly in time. The second …

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3D Model-Based Iterative Reconstruction for Synchrotron Tomography

Introduction and Theory Synchrotron based X-ray tomography is widely used for three dimensional imaging of material samples. Typically, reconstructions are done using analytical reconstruction techniques such as filtered back projection (FBP) or Fourier reconstruction methods like gridrec. However, direct reconstruction of synchrotron data typically result in strong ring and streak artifacts in the reconstruction. The …

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A predictive data mining approach for microstructure optimization

We ask and seek answers for these questions: can we identify the microstructure that is theoretically predicted to yield a desired property demanded by a selected application? What if what’s demanded is a combination of multiple properties? What if there’re more than one microstructure that yield the same property? Can we identify the complete space (or as much of it …

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A unified markov random field/marked point process image model and its application to computational materials

Both Markov Random Field (MRF) and Marked Point Process (MPP) models have their limitations in image analysis. While MRF is a pixel-based representation, it is useful for imposing local constraints, but global constraints are not easily modeled. On the contrary, it is convenient to model global constraints, such as geometric shape and object interactions, within …

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Modeling dynamical scattering using Bethe potentials

Our research focuses on determing the optimal criterion for using the so-called Bethe potentials to reduce the matrix size in electron dynamical scattering calculations and thus the computational time. Electron micrographs display a rich variety of contrast features such as thickness change, bending and defects in the materials. It is important to understand these features …

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Analysis and representation of microstructure data

Recent improvements in experimental and computational techniques in material characterization have led to a vast amount of data on the microstructure and deformation of heterogeneous media. This information is traditionally arrayed in pixels, on grids. The massive extent of data in this form renders identifying key features difficult, and the cost of digital storage expensive. Our following research highlights introduce ways of efficient representation, construction, and analysis.