scholarly journals Multi-scale mechanics of granular solids from grain-resolved X-ray measurements

2017 ◽  
Vol 473 (2207) ◽  
pp. 20170491 ◽  
Author(s):  
R. C. Hurley ◽  
S. A. Hall ◽  
J. P. Wright
Keyword(s):  
Three Dimensional ◽  
Coarse Grained ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical Responses ◽  
Multi Scale ◽  
Granular Solids ◽  
X Ray Computed ◽  
Fundamental Insight ◽  
Particle Force

This work discusses an experimental technique for studying the mechanics of three-dimensional (3D) granular solids. The approach combines 3D X-ray diffraction and X-ray computed tomography to measure grain-resolved strains, kinematics and contact fabric in the bulk of a granular solid, from which continuum strains, grain stresses, interparticle forces and coarse-grained elasto-plastic moduli can be determined. We demonstrate the experimental approach and analysis of selected results on a sample of 1099 stiff, frictional grains undergoing multiple uniaxial compression cycles. We investigate the inter-particle force network, elasto-plastic moduli and associated length scales, reversibility of mechanical responses during cyclic loading, the statistics of microscopic responses and microstructure–property relationships. This work serves to highlight both the fundamental insight into granular mechanics that is furnished by combined X-ray measurements and describes future directions in the field of granular materials that can be pursued with such approaches.

In Situ Three-Dimensional Orientation Mapping in Plastically-Deformed Polycrystalline Iron by Three-Dimensional X-Ray Diffraction

2014 ◽  
Vol 777 ◽  
pp. 118-123 ◽  
Author(s):  
Yujiro Hayashi ◽  
Yoshiharu Hirose ◽  
Daigo Setoyama
Keyword(s):  
Three Dimensional ◽  
Diffraction Method ◽  
Inverse Pole Figure ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Polycrystalline Iron ◽  
X Ray ◽  
Orientation Mapping

In situ three-dimensional crystallographic orientation mapping in plastically-deformed polycrystalline iron is demonstrated using a modified three-dimensional x-ray diffraction method. This voxel-by-voxel measurement method enables the observation of intragranular orientation distribution. The experiment is performed using coarse-grained ferrite with a mean grain size of ~ 60 μm and an incident x-ray beam with a beam size of 20 μm × 20 μm. Grains averagely rotate approximately toward the <110> preferred orientation of body-centered cubic uniaxial tensile texture. Intragranular orientation distributions are spread as the tensile strain increases to 10.7 %. Furthermore, intragranular multidirectional rotations are observed in grains near the <100> and <111> corners in the inverse pole figure.

scholarly journals Mechanisms of root reinforcement in soils: an experimental methodology using four-dimensional X-ray computed tomography and digital volume correlation

2020 ◽  
Vol 476 (2237) ◽  
pp. 20190838
Author(s):  
D. J. Bull ◽  
J. A. Smethurst ◽  
I. Sinclair ◽  
F. Pierron ◽  
T. Roose ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Shear Loading ◽  
Soil Reinforcement ◽  
Experimental Methodology ◽  
Digital Volume Correlation ◽  
X Ray ◽  
Reinforced Soils ◽  
Multi Scale ◽  
X Ray Computed

Vegetation on railway or highway slopes can improve slope stability through the generation of soil pore water suctions by plant transpiration and mechanical soil reinforcement by the roots. To incorporate the enhanced shearing resistance and stiffness of root-reinforced soils in stability calculations, it is necessary to understand and quantify its effectiveness. This requires integrated and sophisticated experimental and multi-scale modelling approaches to develop an understanding of the processes at different length scales, from individual root–soil interaction through to full soil-profile or slope scale. One of the challenges with multi-scale models is ensuring that they sufficiently closely represent real behaviour. This requires calibration against detailed high-quality and data-rich experiments. This study presents a novel experimental methodology, which combines in situ direct shear loading of a willow root-reinforced soil with X-ray computed tomography to capture the three-dimensional chronology of soil and root deformation within the shear zone. Digital volume correlation (DVC) analysis was applied to the computed tomography dataset to obtain full-field three-dimensional displacement and strain information. This paper demonstrates the feasibility and discusses the challenges associated with DVC experiments on root-reinforced soils.

scholarly journals Quantitative grain-scale ferroic domain volume fractions and domain switching strains from three-dimensional X-ray diffraction data

2015 ◽  
Vol 48 (3) ◽  
pp. 882-889 ◽  
Author(s):  
Jette Oddershede ◽  
Marta Majkut ◽  
Qinghua Cao ◽  
Søren Schmidt ◽  
Jonathan P. Wright ◽  
...  
Keyword(s):  
Domain Switching ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Bulk Sample ◽  
Coarse Grained ◽  
X Ray Diffraction ◽  
X Ray ◽  
Volume Fractions ◽  
Fine Grained ◽  
Ferroic Materials

A method for the extension of the three-dimensional X-ray diffraction technique to allow the extraction of domain volume fractions in polycrystalline ferroic materials is presented. This method gives access to quantitative domain volume fractions of hundreds of independent embedded grains within a bulk sample. Such information is critical to furthering our understanding of the grain-scale interactions of ferroic domains and their influence on bulk properties. The method also provides a validation tool for mesoscopic ferroic domain modelling efforts. The mathematical formulations presented here are applied to tetragonal coarse-grained Ba0.88Ca0.12Zr0.06Ti0.94O3and rhombohedral fine-grained (0.82)Bi0.5Na0.5TiO3–(0.18)Bi0.5K0.5TiO3electroceramic materials. The fitted volume fraction information is used to calculate grain-scale non-180° ferroelectric domain switching strains. The absolute errors are found to be approximately 0.01 and 0.03% for the tetragonal and rhombohedral cases, which had maximum theoretical domain switching strains of 0.47 and 0.54%, respectively. Limitations and possible extensions of the technique are discussed.

scholarly journals Measuring and modeling diffuse scattering in protein X-ray crystallography

2015 ◽  
Author(s):  
Andrew H. Van Benschoten ◽  
Lin Liu ◽  
Ana Gonzalez ◽  
Aaron S. Brewster ◽  
Nicholas K. Sauter ◽  
...  
Keyword(s):  
Data Collection ◽  
Diffuse Scattering ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Coarse Grained ◽  
X Ray Diffraction ◽  
Diffuse Intensity ◽  
X Ray ◽  
Protein Motions ◽  
Extra Effort

AbstractX-ray diffraction has the potential to provide rich information about the structural dynamics of macromolecules. To realize this potential, both Bragg scattering, which is currently used to derive macromolecular structures, and diffuse scattering, which reports on correlations in charge density variations must be measured. Until now measurement of diffuse scattering from protein crystals has been scarce, due to the extra effort of collecting diffuse data. Here, we present three-dimensional measurements of diffuse intensity collected from crystals of the enzymes cyclophilin A and trypsin. The measurements were obtained from the same X-ray diffraction images as the Bragg data, using best practices for standard data collection. To model the underlying dynamics in a practical way that could be used during structure refinement, we tested Translation-Libration-Screw (TLS), Liquid-Like Motions (LLM), and coarse-grained Normal Modes (NM) models of protein motions. The LLM model provides a global picture of motions and were refined against the diffuse data, while the TLS and NM models provide more detailed and distinct descriptions of atom displacements, and only used information from the Bragg data. Whereas different TLS groupings yielded similar Bragg intensities, they yielded different diffuse intensities, none of which agreed well with the data. In contrast, both the LLM and NM models agreed substantially with the diffuse data. These results demonstrate a realistic path to increase the number of diffuse datasets available to the wider biosciences community and indicate that NM-based refinement can generate dynamics-inspired structural models that simultaneously agree with both Bragg and diffuse scattering.SignificanceThe structural details of protein motions are critical to understanding many biological processes, but they are often hidden to conventional biophysical techniques. Diffuse X-ray scattering can reveal details of the correlated movements between atoms; however, the data collection historically has required extra effort and dedicated experimental protocols. We have measured three-dimensional diffuse intensities in X-ray diffraction from CypA and trypsin crystals using standard crystallographic data collection techniques. Analysis of the resulting data is consistent with the protein motions resembling diffusion in a liquid or vibrations of a soft solid. Our results show that using diffuse scattering to model protein motions can become a component of routine crystallographic analysis through the extension of commonplace methods.

scholarly journals Multi-Scale X-Ray Computed Tomography Analysis to Aid Automated Mineralogy in Ore Geology Research

2021 ◽  
Vol 9 ◽  
Author(s):  
Mathis Warlo ◽  
Glenn Bark ◽  
Christina Wanhainen ◽  
Alan R. Butcher ◽  
Fredrik Forsberg ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Trace Metal ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Ore Deposit ◽  
X Ray ◽  
Multi Scale ◽  
X Ray Computed ◽  
Automated Mineralogy ◽  
Ore Characterization

Ore characterization is crucial for efficient and profitable production of mineral products from an ore deposit. Analysis is typically performed at various scales (meter to microns) in a sequential fashion, where sample volume is reduced with increasing spatial resolution due to the increasing costs and run times of analysis. Thus, at higher resolution, sampling and data quality become increasingly important to represent the entire ore deposit. In particular, trace metal mineral characterization requires high-resolution analysis, due to the typical very fine grain sizes (sub-millimeter) of trace metal minerals. Automated Mineralogy (AM) is a key technique in the mining industry to quantify process-relevant mineral parameters in ore samples. Yet the limitation to two-dimensional analysis of flat sample surfaces constrains the sampling volume, introduces an undesired stereological error, and makes spatial interpretation of textures and structures difficult. X-ray computed tomography (XCT) allows three-dimensional imaging of rock samples based on the x-ray linear attenuation of the constituting minerals. Minerals are visually differentiated though not chemically classified. In this study, decimeter to millimeter large ore samples were analyzed at resolutions from 45 to 1 μm by AM and XCT to investigate the potential of multi-scale correlative analysis between the two techniques. Mineralization styles of Au, Bi-minerals, scheelite, and molybdenite were studied. Results show that AM can aid segmentation (mineralogical classification) of the XCT data, and vice versa, that XCT can guide (sub-)sampling (e.g., for heavy trace minerals) for AM analysis and provide three-dimensional context to the two-dimensional quantitative AM data. XCT is particularly strong for multi-scale analysis, increasingly higher resolution scans of progressively smaller volumes (e.g., by mini-coring), while preserving spatial reference between (sub-)samples. However, results also reveal challenges and limitations with the segmentation of the XCT data and the data integration of AM and XCT, particularly for quantitative analysis, due to their different functionalities. In this study, no stereological error could be quantified as no proper grain separation of the segmented XCT data was performed. Yet, some well-separated grains exhibit a potential stereological effect. Overall, the integration of AM with XCT improves the output of both techniques and thereby ore characterization in general.

Multi-scale X-ray tomography for process and quality control in 3D TSV packaging

2014 ◽  
Vol 2014 (1) ◽  
pp. 000184-000187 ◽  
Author(s):  
Ehrenfried Zschech ◽  
Sven Niese ◽  
Markus Löffler ◽  
M. Jürgen Wolf
Keyword(s):  
Computed Tomography ◽  
Quality Control ◽  
Process Development ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
X Ray ◽  
Two Dimensional Image ◽  
Multi Scale ◽  
Advanced Packaging ◽  
X Ray Computed

Advanced packaging processes and the resulting 3D products challenge process and quality control. X-ray imaging and X-ray computed tomography (XCT) provide non-destructive characterization capabilities on specimens across a range of length scales, observing features with sizes spanning from millimeters over micrometers down to several 10 nanometers. They are the techniques of choice for two- or three-dimensional inspection of medium and small sized objects with a resolution down to several 10 nm. In this paper, the potential and the limits of XCT for process development, process monitoring, and failure analysis in 3D TSV stacks are described. It is shown that a multi-scale approach, i.e. using imaging techniques with several resolution ranges, is necessary for these particular tasks. Since sub-micron XCT and nano XCT are very useful techniques with a promising prospect for the future, we focus on the capabilities of two lab-based XCT tools with sub-micron resolution (Zeiss Versa) and with &lt; 50 nm resolution (Zeiss Ultra). We demonstrate the capabilities for nondestructive imaging of multi-die stacks with TSVs and AgSn microbumps. Major filling defects in TSVs are clearly visualized. An analysis of individual bumps reveals mismatches in relative positioning, micron-size pores, and the distribution of intermetallic phases. This information provides important information regarding the respective process steps (process control) and the product quality (quality control). In addition, TSV etch profiles and small voids in Cu TSVs are visualized. Since deviations from the targeted geometry and defects are difficult to locate precisely from a two-dimensional image, X-ray computed tomography has to be applied.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

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