Statistical Engineering Division Seminar

Dr. Edward J. Garboczi
Leader, Inorganic Materials Group
Materials and Construction Research Division
Building and Fire Research Laboratory
Thursday, May 8, 2008, 10:45-11:45 AM
Building 222, Room A330

Abstract

It has been estimated that 70 % of industrial processes involve some kind of particles, and of course, particles are ubiquitous in nature. Their size scale, for both man-made and naturally-occurring particles, range from a few nanometers up to many meters. This talk focuses on using a combination of X-ray computed microtomography (CT) and spherical harmonic analysis to characterize and model the shape of particles, in three dimensions, ranging in size from tens of millimeters down to tens of micrometers. There will also be some mention of focused ion beam techniques that can investigate sub-micrometer particles. The particles I have been mainly interested in have been those found in the cement and concrete industry (e.g., cement, sand, gravel), although I have studied other kinds of particles as well, including glass beads and calcium carbonate powders, and studies have been initiated on simulated lunar soil particles. Once the particles have been mathematically characterized, almost any kind of volume or surface integral can be performed for each particle, allowing for many shape parameters to be calculated. One result of the availability of having many shape parameters is that the “size� of particles turns out to be intimately related to their shape. An outstanding statistical problem is to generate new particles that are statistically “like� those of a class of particles that have been previously characterized. Progress on this problem will also be discussed.