John R. Dunning
Do you remember using the X-ray powder diffraction system (XRD) in Physics 316?
Well the analysis system for unknown compounds just got much better.
State-of-the-art search and match software, trade named Jade Plus , has been funded by our campus Library
and Information Technology Committee. The powder diffraction file of patterns to search for has been upgraded to include 62,000 different compounds. Through Dr. Edward Liston, the Philatelic Foundation in New York has funded a state-of-the-art PC to run these programs. The new 17-inch monitor and a lightning-fast 150 MHz Pentium arrived in April. They are a joy to use.
Greg Madruga has been comparing the ink on modern and 1903 era stamps using
both the present XRD system and our X-ray fluorescence system. Amazingly, the
ink forms sufficiently fine crystals on the stamp to analyze by simply laying the stamp on a sample holder. At present, our exposures of the stamps to X-rays are sufficiently short that no visible browning is observed. And, yes, there are significant differences in composition between modern and ninety-year-old stamps. Greg is working on a paper describing the details.
We propose to be even better.
Our NSF proposal is currently pending for a brand new Scanning
Electron Microscope (SEM) with elemental analysis via detecting the X-rays. This involves five SSU departments and seven faculty directly. When installed, this instrumentation will provide surface elemental composition for all elements down to and including number five, boron. This information will be added to the above crystal structure
determination to help identify the harder cases. Also the SEM provides a picture of the unknown sample. We all know a picture is worth 1000 words.
