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Opportunity at National Institute of Standards and Technology   NIST

Measurements and Modeling of Particle Shape and Properties

Location

Material Measurement Laboratory, Applied Chemicals and Materials Division

opportunity location
50.64.72.B8253 Boulder, CO

Please note: This Agency only participates in the February and August reviews.

Advisers

name email phone
Ann Chiaramonti Debay chiaramonti@nist.gov 303.497.5701
Edward Joseph Garboczi edward.garboczi@nist.gov 301.318.8618

Description

Particulate materials, ranging in size from millimeters to nanometers, play an important role in many natural (e.g., soils) and industrial (e.g., metallic additive manufacturing) applications. In many of these applications, the shape of the particles plays a key role (e.g., soil strength, suspension rheology, granular flowability, light scattering from aerosols and lunar soil, composites) in structure and properties. At NIST-Boulder, there is a world-class program in measuring particle shape and size in three dimensions (3D) using X-ray tomography and scanning and transmission electron microscopy, and modeling the 3D shape using spherical harmonic series. However, for random non-spherical particles, shape and size measurements are often interdependent. Some of the characterized particles are then used in various computational models, including the generation of statistically similar particles. Many opportunities exist in this area involving experimental and computational approaches to particle problems in 3D, including new methods of 3D measurement and new applications of 3D particle shape data. This opportunity mostly focuses on inorganic particles, but proposals involving organic/biological particles can be considered. Collaboration with NIST-Gaithersburg particle research is also possible.

 

References

Garboczi EJ: Three-dimensional mathematical analysis of particle shape using x-ray tomography and spherical harmonics: Application to aggregates used in concrete. Cement and Concrete Research 32: 1621-1638, 2002

Taylor TA, Garboczi, EJ, et al: Some properties of irregular particles in 3-D. Powder Technology 162: 1-15, 2006

Erdogan ST, Fowler DW, Garboczi EJ: Shape and size of microfine aggregates: X-ray microcomputed tomography vs. laser diffraction. Powder Technology 177: 53-63, 2007

Liu X, Garboczi EJ, et al: Spherical harmonic-based random fields based on real particle 3D data: Improved numerical algorithm and quantitative comparison to real particles. Powder Technology 207: 78-86, 2011

Garboczi EJ: Three Dimensional Shape Analysis of JSC-1A Simulated Lunar Regolith Particles. Powder Technology 207: 96-103, 2011

Garboczi EJ, Liu X, Taylor MA: The Shape of a Blasted and Crushed Rock Material over More than Three Orders of Magnitude: 20 mm to 60 mm. Powder Technology 229: 84-89, 2012. DOI: 10.1016/j.powtec.2012.06.012

Garboczi EJ, Bullard JW: Contact function, uniform-thickness shell volume, and convexity measure for 3D star-shaped random particles. Powder Technology 237: 191-201, 2013. 10.1016/j.powtec.2013.01.019

Bullard JW, Garboczi EJ: Defining shape measures for 3D star-shaped particles: Sphericity, roundness, and dimensions. Powder Technology 249: 241-252, 2013

Slotwinski JA, Garboczi EJ: Characterization of Metal Powders Used for Additive Manufacturing. Journal of Research of the National Institute of Standards and Technology Volume 119, 2014. http://dx.doi.org/10.6028/jres.119.018

Qian Z, Garboczi EJ, et al: Anm: A geometrical model for the composite structure of mortar and concrete using real-shape particles. Materials and Structures, 2014. DOI: 10.1617/s11527-014-0482-5

Audus DJ, et al: Interplay of particle shape and suspension properties: A study of cube-like particles. Soft Matter 11: 3360-3366, 2015. DOI: 10.1039/C4SM02869D (2015)

 

Keywords:
Particles; Shape; Size; Properties; Light scattering; Composites; Characterization; Modeling; Spherical harmonics; X-ray tomography; Scanning electron microscopy; Transmission electron microscopy; Flowability; Granular media; Composites; Soil; Suspensions;

Eligibility

Citizenship:  Open to U.S. citizens
Level:  Open to Postdoctoral applicants

Stipend

Base Stipend Travel Allotment Supplementation
$74,950.00 $3,000.00
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