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2011 Tour Speaker Program

MAS provides interesting technical speakers for meetings of its Affiliated Regional Societies (AReS).


Speaker Bio Title Abstract
Ed Vicenzi


Ed Vicenzi

Edward Vicenzi is a research scientist and microanalysis expert at the Smithsonian Institution’s Museum Conservation Institute. He uses a variety of techniques to probe natural materials to understand their origin and history. Ed has previously served as a researcher at the US National Museum of Natural History, a staff member at Princeton University, and a postdoctoral fellow at Macquarie University in Australia. He obtained his BSc from McGill University, MS from the University of Oregon, and his PhD from Rensselaer Polytechnic Institute all in Earth Sciences.    

Microanalysis of Martian Salts From The Comfortof Your Laboratory

Over the past decade information regarding minerals precipitated from ancient bodies of water on Mars has become available from spectrometers/cameras systems mounted on orbital spacecraft. Ground-based studies of rocks by the Mars Exploration Rovers have added significant, and unique, detail to our understanding of these deposits.  Microanalysis of carbonates and sulfates in Martian meteorites yield perhaps the greatest wealth of chemical data concerning their origin, as these specimens are available in-hand for Earth-based laboratory studies.  One drawback to meteorite analysis of Martian salts is the potential terrestrial overprinting for samples that have been subjected to Earth’s atmosphere/hydrosphere for 1000s of years in some cases.  Careful microscale examination of these precious specimens give clues to which materials formed preterrestrially (on Mars) versus those that formed after their arrival on Earth.

 Robert Simmons
  
 Robert Simmons

Robert Simmons is a native of Atlanta, Georgia. He earned his Bachelor of Science (Hons) degree in biological sciences at the University of Ulster, and continued with MS and Ph.D. degrees at Georgia State University. He joined the Biology Department at Georgia State University in 1983 and is the Program Director for Biological Imaging. He teaches laboratory courses for TEM and SEM plus a survey of imaging technology lecture course at Georgia State. His main research involves the interaction of microorganisms with the human environment, with an emphasis on fungi and air handling systems. Recent work of a slightly different nature includes X-ray microanalysis of glass used for making art glass jewelry.

Microorganisms and You: A Tale of Cohabitation

Many microorganisms are primarily recyclers. Their main function in the environment is to break down complex materials, which allows the components to be re-used by other organisms. These complex materials include dead plants, dead animals, building materials, valued artifacts of civilization and any number of other things.  Problems arise when these organisms invade the built environment such working/ living spaces or even the air handing systems of our vehicles. Various methods, such as air sampling, surface cultures and bulk sample analysis have been used to estimate the density of organisms in a given environment. Volumetric sampling may indicate high levels of fungi or one particular fungus in a building compared to the outdoor environment or some predetermined standard. This method may indicate the presence of viable fungal conidia or hyphal fragments in the air column but it cannot identify sites of fungal colonization. Surface cultures may indicate the presence of viable fungal propagules but do not prove colonization. Surface sampling for light microscopy using clear adhesive tape mounts may demonstrate the presence of colonizing fungi. The methodology, such as types of tape and optics employed may affect the results obtained. Examination of tape samples from environmental surfaces may show the level of colonization and, in many cases, allow for identification of colonizing species. Electron microscopy studies of suspect materials may determine the nature of surface features and types of microbial contamination not readily identifiable in the light microscope. Suspect materials may be shown to be biological in nature or non-biological surface. Microanalysis of materials may yield clues to the origin of non-biological contamination. Rapid and accurate analysis of suspect materials on indoor surfaces is vital to the identification of potential microbial colonization sites. These data may be used as an aid to determining an appropriate course of action.

Previous Years Speakers


Paul Hlava
  
 Paul Hlava

Paul Hlava recently retired from Sandia National Laboratories in Albuquerque, New Mexico after 33 years. He worked in the electron microprobe laboratory (as staff member in charge of the lab since 1980)  the entire time. Because the EMP lab is part of the Materials Characterization Department, a centralized analytical facility for Sandia, Paul got to work on a wide variety of (prosaic to exotic) materials and projects.  He normally analyzed many alloys and joins  (welds, brazes, solders, metal to ceramic, glass/metal seals, etc.) but also did work on high tech ceramics, low-temperature superconductors, electronic materials, phosphors, contamination, corrosion,  failure analyses, nuclear waste simulants, thermal batteries, et hoc genus omne. As a result, he has written, co-authored, and/or presented over a hundred papers on a wide variety of materials.

Paul graduated from the University of New Mexico  with a geology MS in 1974. At UNM he worked as a research graduate doing probe research under Klaus Keil in the Institute of Meteoritics. He worked on moon rocks, Hawaiian basalts, ultramafic rocks,  meteorites, and inclusions in diamonds. Paul occasionally uses his geological and mineralogical expertise on Sandia projects but also does some personal research on minerals. He has been co-discoverer and co-author on the descriptions of several new mineral species.

Paul stays active in the area of geology, mineralogy, crystallography, and gemology. He has been president of the Albuquerque Gem and Mineral Club three times. He is the Chair for AGMC's annual show, geological/mineralogical expert for the New Mexico Facetors Guild, and often gives talks on geological/mineralogical/ crystallographic/  gemmological subjects. About twenty years ago, Paul started a side business, Access to Gems and Minerals, Inc., dealing in gemstones, jewelry, and related items. This has not only given him access to wholesale rooms full of gemstones but it has piqued his interest in the research side of this field. He has given several well-received talks on gem related subjects such as this one.

Since retirement Paul has dabbled in penny stocks. Buying low isn’t difficult it’s the selling high that takes skill.

The Materials Known as Gemstones 

Unlike most materials, gemstones are prized for beauty first; all other properties are of secondary interest. Other materials are chosen for various applications because they are strong or weak, hard or soft, insulating or conductive, transparent or opaque, et hoc genus omne. In defining gem and gemstone, I will show that some properties, such as hardness, durability, cleavage, etc. are also considered important. These definitions also introduce properties such as rarity and high cost or intrinsic value. By discussing the BIG seven (the more precious of the gemstones – diamond, emerald, ruby, sapphire, tanzanite, opal, and pearls – or DERSTOP), I will show how arbitrary is our consideration of these other properties compared to the all important property of beauty. A brief mention of other gemstones will illustrate the many varieties of beauty desired by people.

Crystal form is a property of the “rough” gem material which, unexpectedly, often carries over into the shape of the polished  gemstone. The shape of the original crystals and the desire to waste as little of this most valuable material as possible are mostly responsible for the creation of the standard round brilliant cut of the diamond, the emerald cut of the emerald, and the ovals of ruby and sapphire. I shall mention where history has also played a part in determining these gemstone shapes.

I will discuss the distinctions between natural, synthetic, and  simulated gemstones. Because natural gemstones (mined from the Earth, then ground to shape and polished) are so valuable and pricey, people (some with honorable intentions and some not) have been working to make lower cost substitutes. There have been many successes. Synthetic gemstones (also known as lab-grown, “cultured”, etc.) are medium- to low-cost materials of the correct chemical composition and physical properties. Simulants may look like a particular gemstone but are inexpensive to cheap (in all ways) substitutes for the “real” thing.

I will end with general guidelines to the properties one should consider when purchasing a gemstone. The guidelines for diamonds is quite specific and considers the properties of color, clarity, cut, and carat weight (the 4 C’s of diamond buying). The guidelines for colored stones are more generalized.

*This talk was originally developed for the Albuquerque chapter of ASM International, “The Materials Information Society,” ergo the emphasis on properties.

Paul Kotula
  
 Paul Kotula

 or

Joe Michael

MichaelJR2009.jpg

Paul Kotula is a Principal Member of Technical Staff in the Materials Characterization Department at Sandia National Laboratories in Albuquerque, NM. Paul received his B.S. from Cornell University and Ph.D. from the University of Minnesota, both in Materials Science and Engineering. Before joining Sandia, he was a Postdoctoral Fellow at Los Alamos National Laboratory. His work at Sandia includes analytical electron microscopy support for microelectronic and micro-electromechanical device development, welding, brazing, soldering, forensics, process feedback, failure analysis, and 3D materials characterization and microanalysis. He has helped build a research program on spectral imaging and automated multivariate statistical analysis. The software developed from this work for x-ray microanalysis is commercially available from Thermo Fisher Scientific and is now in over 500-labs worldwide. It is also in research-form in over 25-labs worldwide. Paul’s work has also garnered several awards over the years, among them an R&D 100 Award in 2002, two Best Analytical Techniques paper of the year in the journal Microscopy and Microanalysis (2003, 2006) and the Heinrich Award for outstanding young scientist from MAS in 2008.

Paul has been an Adjunct Professor in the Department of Materials Science and Engineering at North Carolina State University since 2001 and has authored or co-authored over 70 journal articles on a wide variety of topics involving electron microscopy and microanalysis as well as two patents and two book chapters. He was also a Director of MAS (2002-2004), a Tour Speaker (2003-2004) and President of the Society (2006-2007).

Joe Michael is a Distinguished Member of the Technical Staff at Sandia National Laboratories in Albuquerque, NM. He currently works in the Materials Characterization Department of the Materials Science Center where he develops and applies electron and ion microscopy to the characterization of materials. Prior to coming to Sandia in 1990, Joe worked as a Senior Research Engineer in the Homer Research Laboratories of the Bethlehem Steel Corporation. He received his BS, MS and PhD. in Materials Science and Engineering from Lehigh University in Bethlehem, Pa. Notable awards for Dr. Michael include the Microscopy Society of America Burton Medal, an R&D 100 Award, the International Center for Diffraction Data’s Hanawalt Award, the Microbeam Analysis Society’s Heinrich and Presidential Science Awards, and the ASM’s Grossman Award. Joe is a Fellow of the Microscopy Society of America. He is a co-author of the leading textbook on Scanning Electron Microscopy. Joe has authored many book chapters and has published over 100 papers in the areas of materials science and electron microscopy.

Microanalysis and the FBI's Amerithrax Investigation of the 2001 Anthrax Attacks 

The Anthrax attacks of 2001 in the US killed 5, sickened 22 others and caused a significant disruption of mail and other government facilities. Although the attack materials were for the most part recovered (Bacillus Anthracis) in powder form in sealed envelopes, the US Federal Bureau of Investigation (FBI) was unprepared to perform the needed forensic analyses on these bio-weapon materials. In particular, it was identified that microanalysis from the micro- to nano-scale was a key missing piece of their capabilities. As a result, Sandia was asked to analyze the materials from the attacks by early 2002 and we reached our general conclusions within a few months. We also analyzed over 200 samples of B. anthracis between 2002 and 2008 in an attempt to discern the method of manufacture of the attack materials.

This talk will describe Sandia's involvement in the FBI's investigation and in particular the power of microanalysis in answering several critical questions: Was the Bacillus Anthracis intentionally weaponized (i.e., contain an additive to make it disperse predictably) and were the materials from the attacks from the same source? In particular x-ray spectral imaging (in the SEM and STEM) combined with multivariate statistical analysis were used to answer these questions. Specimen preparation was both by conventional microtomy and focused ion beam (FIB) sectioning of spore preparations. In addition, significant advances in analytical throughput were achieved by modification of a FE-SEM with an annular Si-drift detector with a solid angle of over 1 steradian. STEM in SEM was then performed with this new hybrid instrument in order to analyze large numbers of spores in a short time.

Nestor Zaluzec

   Nestor Zaluzec

A senior scientist and principle investigator in the Electron Microscopy Center at Argonne National Laboratory, Nestor is a Fellow of both Oak Ridge National Laboratory, and the Computational Institute of the University of Chicago, a Visiting Professor of Physics at Northern Illinois University and a Fellow of the Microscopy Society of America. Nestor's research includes the development of state-of-the-art instrumentation and techniques for atomic resolution x-ray and electron spectroscopy, analytical, and scanning confocal electron microscopy. In addition to creating tools for science, he also uses these leading-edge technologies to study issues in technologically important materials. His work over the last 30 years has included studies in the areas of structural phase transformation in metals, radiation damage in alloys, ceramic oxides for geologic immobilization of nuclear waste materials, elemental segregation in semiconductors devices, magnetism, genetically engineered proteins for bio-materials nanoarrays and most recently studies of catalysis using analytical microscopy. He was one of the earliest to realize the potential impact of the Internet on science and established the first TelePresence Microscopy Collaboratory, which is serves as a model for outreach to both the scientific and education communities, providing unencumbered access to scientific resources.

Nestor received his B.S. degree in Physics at Illinois Institute of Technology in Chicago, and his PhD in 1978 from the Department of Metallurgy at the University of Illinois Urbana-Champaign.

Have your Pi and EDS too: A Transmission X-ray Detector for Nano-Particle Analysis

In nano-materials research, one of the ubiquitous instruments we employ for characterization is the electron microscope. After electrons, the signal most often measured in these instruments is the emission of characteristic x-rays. During the last 40 years, either the solid state Si(Li) or more recently the SDD Energy Dispersive Spectrometer (EDS) have been the detector most often used for this task. On one hand these detectors are remarkably, simple and efficient devices, but on the other there nearly always remains opportunities for improvement.

One of the factors which governs the ability to measure an x-ray signal is the detector geometrical collection efficiency and is typically defined in terms of the collection solid angle . For EDS systems interfaced to a scanning electron microscope (SEM) values can range from < 0.005 to ~0.1 sR, while in transmission or scanning-transmission electron microscopes (TEM/STEMs) values of up to ~ 0.1- 0.3 sR have become routine.

To improve this situation specifically for nano-particle characterization, a prototype 42.5 mm2 SDD x-ray detector which operates in a novel transmission configuration has built and has been interfaced to the column of a FEG-ESEM. The detector is enclosed in a stainless steel housing (0.75" in diameter), while the detector crystal is protected from electron irradiation by using a 12.5 µm thick Be window. In this geometry, nano-particle specimens for analysis are supported on TEM grids held in a custom built, Be shielded stage, which can be adjusted using the existing SEM stage translation mechanisms. The SDD detector is inserted beneath the specimen by means of a standard linear insertion mechanism interfaced to a side entry port of the microscope. At closest distance tested the detector solid angle just exceeds 3.14 sR. Research continues to refine the performance and solid angle of this configuration, as well as to consider alternative configurations for use in TEM geometries.

 

Remember that all arrangements by Affiliated Regional Societies for Tour Speakers must be made through the MAS AReS Director.

   
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