Working With Living Cells – Triumphs, Tribulations, and Tragedies
Jeremy Pickett-Heaps, University of Melbourne School of Botany, and Brian J. Ford, Cambridge University, Gonville and Caius College
This was an open, informal and wide-ranging discussion of any aspect of video microscopy of living specimens in which delegates are interested. There will be discussions of equipment (e.g. cameras, tape decks, etc.) and illustrations of how various preparative methods work in practice using published sequences of unusual and/or difficult material (including slime molds, feeding protozoa, etc.). Topics to be discussed will include: choice of microscope; sturdiness; second-hand and antique microscopes; macroscopy (including darkfield illumination); attaching the camera to the microscope; coping with vibration; choosing specimens; cleaning glass surfaces in lenses; the critical importance of using healthy cells; mounting specimens; time-lapse and the importance of shutter control of specimen illumination. Attendees will learn how they can obtain images through the most unlikely microscopes, including primitive or antique methodologies. Emphasis will be given on how some technical problems were resolved – and how many others still await inspired new approaches.
Airborne & Settled Dust Particle Identification
Andrew A. Havics, pH2, LLC, and Randy Boltin, MVA Scientific Consultants
This one-day workshop investigates the types of particulate matter that commonly occur as indoor environmental contaminants. Participants will learn the identifying characteristics and significance of those particles most frequently encountered during indoor environmental quality (IEQ) surveys as well as relevance with regard to some common maladies or building conditions associated with certain types of particles. Special methods of dealing with opaque particles (rubber, combustion, metals/corrosion) will also be presented. Common sampling methods for both air and surfaces, as well as their comparative advantages and disadvantages will be dealt with as they relate to the microscopical examination of samples.
Techniques and Instrumentation
New Directions in the Design of Polarized Light Microscopes
Jan Hinsch, Leica Microsystems
In 2003, the first of a new series of Polarized Light Microscopes from Leica appeared – the DM EP. Early this year two more instruments, the DM P 2500 and DM P 4500 were introduced to upwardly complete the line. Both microscopes go well beyond the features of the DM EP. With this talk I will present the design philosophy behind these new arrivals and how they reflect the conclusions of its designers where polarized light microscopy is headed.
Using Digital Imaging to Enhance the Performance of Your Microscope
Tony Havics, pH2, LLC
Most microscopists look to align, calibrate and refine their microscopes in order to produce better digital images. But by reverse engineering, the digital images can be used to enhance the alignment and performance of the microscope – light and electron. Examples include alignment of illumination, determination of best focus, determination of resolution (not how you think), evaluation of astigmatism, evaluation of spherical aberration, and so on.
Video Microscopy of Living Cells: Getting Started
Jeremy Pickett-Heaps, University of Melbourne School of Botany
This illustrated presentation will introduce fundamental and important technical considerations involved in setting up video systems capable of imaging living cells. Topics included range from the choice of microscope to the selection of cells. These topics will be more fully explored in a practical setting during the subsequent Workshop.
Brian J. Ford, Gonville and Caius College, Cambridge University
It is 40 years since Brian showed his remarkable micrographs of erythrocytes in hemostasis. Some of his early work was published in Volume 17 of The Microscope in 1969. The research has recently been the subject of invited contributions to current journals, and this presentation sets the original research in a present-day context.
Nano-Tubes and Nano-Particles
James R. Millette, MVA Scientific Consultants
It is generally accepted that some nano-materials may have the potential to cause harm to people and the environment. As the toxicology of certain types of nano-particles becomes clear, exposure evaluation will be necessary to address the health concerns. The finding of nano-materials may also prove useful as clues in forensic studies. There is no comprehensive list of products that currently contain man-made nano-materials but it spans the range from pharmaceutical delivery systems to baseball bats. Microscopy will be an important tool in assessing the presence of nano-materials because many nano-particles such as nanotubes and clusters of fullerenes, molecules composed of 60 carbon atoms, are best characterized by their morphology. Microscopy is already used to characterize nano-particles of metal fumes and aggregates of nano-particles of aciniform soot generated by various sources of combustion. Among the first challenges facing the microscopy community are the validation of methods of collection for nano-particles and the development a database of known nano-materials.
New High Speed Raman Imaging with Laser Line Focus and Synchronous Sample Scanning for Pharmaceutical Product Analysis
Richard Bormett, Renishaw, Inc.
The ability to create chemical images by acquiring Raman spectra from an array of positions and then processing them to reveal the parameter of interest is a powerful chemical imaging technique. Traditionally, these spatially related data have been collected by raster scanning the sample beneath the incident laser focused to a point or to a line, typically in micrometer intervals. A new method of sample scanning combined with the static laser line focus has been developed that dramatically increases the image acquisition speed without compromising Raman image or spectrum quality. This innovative approach allows the Raman imaging to be applied to small and large areas where it had previously been impractical due to time constraints that would otherwise produce poor spectral signal-to-noise. Raman imaging is now possible for large and small areas at speeds much greater than possible with traditional methods. Pharmaceutical examples will be shown to illustrate the benefits of this method.
High School Criminalistics Course Emphasizing Forensic Microscopy
Wayne Moorehead; and Sid Rogers, Cerritos High School
Because many non-forensic instructors of science consider criminalistics and forensic science simply as an application of their science while others view forensic science as ‘‘edutainment,’‘ rarely do they have an understanding of the philosophy, application, and comprehension of the difference between forensic science and their particular science. A high school instructor teamed with a practicing forensic scientist to develop a year-long high school curriculum representing a realistic criminalistics course. The presence of stereo microscopes and biological, light microscopes presented several good opportunities:
1. to teach students to use microscopes
2. because most schools have microscopes
3. to learn practicality of physics theory on light and optics
4. because microscopes require the user to observe and critically think about their analysis
5. to acquire a variety of analytical skills at the microscopical level
6. to easily convert biological, light micro scopes to polarizing light microscopes for chemical microscopy
The course was designed for the college bound high school science student who had already taken biology and chemistry. Students followed the six foundational concepts of criminalistics with an emphasis on observing, documenting, and communicating, the essential aspects of microscopy. Laboratory exercises were developed based on skill set building, critical thinking and problem solving. Constant feedback, particularly of unanticipated irregularities, meant instant revisions in content. At the end of the semester, in addition to a comprehensive written exam, students were required to use all of the skill sets, write a final report on their analyses with inclusion of data, provide a courtroom presentation poster, and testify about their work.
The Light Microscope in Multi-Disciplinary Analysis
Andrew M. Bowen, Stoney Forensic, Inc.
The light microscope plays an integral part in any analytical scheme that involves several different types of instruments. The data obtained from most analytical instruments can be interpreted with much greater confidence when combined with the information available from light microscopy. In addition, the light microscope plays a critical role in decision-making during analysis of non-standard samples, such as those encountered in forensic situations. The role of the light microscope in multi-disciplinary analysis will be discussed in the context of recent case examples.
Diketopyrrolo-Pyrrole (DPP) Pigments: A Look at Their Characterization and Identification
Meggan King, McCrone Research Institute
The DPP pigments are one of the newest groups of synthetic organic pigments available today. Since their discovery in 1974, their use has steadily grown. These pigments range in shade from orange to red and can be found in artist’s paint, industrial and automotive coatings and plastics. Synthetic organic pigments are notoriously difficult to identify. These new pigments can pose a challenge to art conservators and forensic scientists. Previously published methods by Vesce and Zona will be addressed as well as the use of modern instrumental analysis. This presentation will propose to evaluate various microscopical techniques that could be used to aid in their characterization and identification.
Vibration Sensitivity of Optical Microscopes
Dr. Hal Amick, Colin Gordon & Associates
Bench-mounted optical microscopes have a wide variety of applications in science and technology. This paper presents the results of experimental studies addressing their vibration sensitivity as well as the amplification and attenuation provided by typical laboratory casework. The vibration sensitivity was found to be a function of magnification, vibration direction, support conditions and the presence or absence of ‘‘peripherals’‘ such as electrophysiology apparatus. The benchtop vibration amplitudes at which the effects of motion first become perceptible were found for magnifications of 40x, 100x, 400x and 1000x using sinusoidal excitation. In addition, the amplitudes associated with several (subjective) levels of image degradation were explored.
Options are examined for future work which might document relationships between vibration parameters (e.g., amplitude and frequency) and quantifiable performance parameters such as loss of resolution viewing spheres of known size or degradation in fourier space.
Typical floor vibration in lab buildings is reviewed in the context of potential effects on microscopy. Transfer functions were determined for benchtop motion with respect to floor motion, using both conventional casework and a representative pneumatic isolation bench. Floor vibration criteria were developed for microscopes with the two types of support.
Using the Olympus E-330 DSLR Camera with Compound and Stereomicroscopes
Theodore M. Clarke
The recently introduced Olympus E-330 DSLR camera has a 7.5 mega pixel CMOS sensor. A live view feature allows critical focusing from a selected area of the sensor displayed at full resolution required for satisfactory use on a microscope. The Olympus f/2.8 28 mm lens mounted in the MF-1 adapter and focused at infinity allows an 18 mm FN of a 10X eyepiece, which need not be high eyepoint, to be recorded with the E- 330 held separately from the microscope in a suitable stand. This capability is especially useful for older design microscopes using compensating eyepieces as well as for stereo-microscopes. This camera was used in a study to resolve vibration issues with a modified Lomo Biolam using oil immersion objectives. It was also used with a novel, multimode, transmitted light illuminator for stereo microscopes.
Drawn and Undrawn Fibers
Gary J. Laughlin, McCrone Research Institute
In fiber and textile terminology the terms ‘‘undrawn fiber’‘ and ‘‘drawn fiber’‘ are used to describe stages in the production of polymer fibers. To the polymer microscopist, the word ‘‘undrawn’‘ is misleading because the resultant filaments are noticeably drawn but with much variability in their physical, mechanical, and optical properties; making them more difficult to identify. This talk will describe the macroscopic and microscopic deformation process and how it influences these optical properties, especially those readily observed and measured (refractive indices, birefringence, etc.) by polarized light microscopy.
Space Shuttle Stiffener Ring Foam Failure Analysis: A Non-Conventional Approach
Philip M. Howard, NASA Kennedy Space Center
The Space Shuttle makes use of the excellent properties of rigid polyurethane foam for cryogenic tank insulation and as structural protection on the solid rocket boosters. When foam applications debond, classical methods of analysis do not always provide root cause of the failure of the foam. Realizing that foam is the ideal medium to document and preserve its own mode of failure, thin sectioning was seen as a logical approach for foam failure analysis. Thin sectioning in two directions, both horizontal and vertical to the application, was chosen to observe the three dimensional morphology of the foam cells. The cell foam morphology provided a much greater understanding of the failure modes than previously achieved.
The Box, Experiment No. 4, and Two Books by Elizabeth Wood
Most analytical microscopists are familiar with Elizabeth Wood’s book ‘‘Crystals and Light An Introduction to Optical Crystallography.’‘ The full title of the first edition was ‘‘Special Edition for Bell System Science Experiment No. 4 Crystals and Light; An Introduction to Optical Crystallography.’‘
My curiosity about ‘‘Experiment No. 4’‘ was answered when a friend of mine brought to me a blue box with a variety of die-cut paperboards, a smaller box with a variety of objects, five labeled vials, several full and half-slides, and a lamp with a cord but no bulb. He said he had found this box of stuff but didn’t know its application. In checking the book by Elizabeth Wood, ‘‘Experiments with Crystals and Light, Bell System Experiment No. 4,’‘ the significance of the contents of the box became clear.
This presentation will explore the contents of the box, the book of experiments and the optical crystallography book written by Elizabeth Wood, and portray some of the results of the experiments.
The E-Learning Imperative – Microscopy at a Distance
Brian J. Ford, Gonville and Caius College, Cambridge University
Traditional formal training is being supplanted by e-learning. Does this mean the end of institutes? Are we witnessing the end of the era of the great teacher? What are the implications of the internet in the world of specialist education? And are the courses effective? In this evening’s presentation (live and online) we will find out more about the e-learning revolution and discover some surprising truths about the future of microscopy on the net.
Environmental and Industrial Microscopy
Adventures in Microscopy: Learning a Little About a Lot of Things, While Learning a Lot About Little Things
Kevin Brady, Tredegar Film Products
The light microscope is a great catalyst for science education. As a microscopist in a plastics industry analytical laboratory, I never know what my microscopy lab has in store for me. Even the most mundane looking samples can suddenly launch me on a safari through the fields of mineralogy, mycology, botany, etc… Sometimes the learning continues long after the initial problem has been solved. Images from some of my own excursions far from plastics industry will be resented.
Sebastian Sparenga, McCrone Research Institute
These days, people use the word extreme to describe just about everything, including Frisbee, fishing, and even walking. Why not microchemistry? A case example involving the microchemical analysis of glass samples to test for the presence of boron will be discussed. The procedure requires much practice and patience, hence warranting the ‘‘extreme’‘ title.
The In-Situ Identification of Pigments in CMYK Printing Inks
Chris Palenik and Brendan Nytes, Microtrace, LLC
The Raman microprobe is a powerful tool for phase characterization of microscopic and sub-microscopic particles. This talk will provide a basic introduction to the theory of Raman spectroscopy, but focus mainly on the ways in which Raman can be used to supplement traditional microscopical problem solving techniques. In particular, the in situ analysis of traditional four-color CMYK printing ink will be presented. Using Raman spectroscopy, the pigments used to produce the standard color cyan ( C ), magenta (M), yellow (Y) and black (K) in several inks were identified without removing the ink from the paper. In areas of overlapping ink used to produce composite colors, the individual component pigments can be resolved and identified.
Characterization of Fibrosity in Amphibole Minerals
Eric J. Chatfield, Chatfield Technical Consulting LTD
Current controversy regarding ‘‘naturally occurring asbestos’‘ relates to whether individual fibers of amphiboles such as tremolite and actinolite can be classified as asbestos or whether they should be classified as non-asbestiform. This controversy has arisen in environmental measurements in several locations in the U.S. and elsewhere.
In a hand sample, a fragment of massive tremolite or actinolite appears superficially to exhibit none of the characteristics of asbestos. However, on crushing such minerals, a small and variable proportion of long, thin fibers is produced. Similar crushing of the apparently asbestiform variety of the same mineral may, but does not necessarily, produce a high proportion of long, thin fibers. It appears that some of the properties of these amphibole minerals are not fully understood.
A series of experiments has been conducted on various varieties and different sources of amphibole minerals to collect data on the sizes of fibers produced following crushing. The data appear to show that the propensity of an amphibole mineral to produce long, thin fibers on crushing is a variable that is not completely related to its appearance.
Comparative Study on Outdoors Spores in New York
Eliza Domenech, ATC Associates, Inc.
The purpose of this short technical paper was to gather an insight as to what types of spores are prevalent during the year in the New York area. Our detailed findings were for the time period of January 1st 2005 through December 31st, 2006. There were similar findings achieved and published in journals in Europe and USA in reference to spore population by month during the year.
Our study is a work in progress for we’re developing a useful database that will serve as a guide for mold issues with indoor air quality. In the context of this knowledge, what types of spores are present in outdoor air will serve as an instrument and an indispensable tool to help in identifying any indoor mold issues. Using this approach, we can target and learn more about what types of spores that are in our environment. Achieving this goal provides the Industrial Hygienist, with client consultations, the data that’s pertinent to their specific mold issues.
Using Quantomix Cells for Observing Aqueous Crystallization of Gypsum and Portland Cement in a Conventional Scanning Electron Microscope (SEM)
Arthur W. Struss, USG Research
Quantomix capsules enable the imaging of wet samples in a conventional Scanning Electron Microscope (SEM) using Backscatter Electron Imaging (BEI). A thin electron-transparent membrane is used to separate the aqueous sample from the vacuum in the SEM chamber. The capsules have been used to image biological samples, plant tissue, and personal care products. In this study, early crystallization of gypsum using crystal modifiers and the early hydration of Portland cement systems were investigated. Image resolution, the interaction of the electron beam with the membrane, and other experimental parameters will be reviewed.
Direct Observation of Asbestos Fibers on Contaminated Cotton Fabric and Measurement of Fiber Release
Eric J. Chatfield, Chatfield Technical Consulting LTD
A recent lawsuit involved woven cotton fabric that had been removed from asbestos-containing pipe insulation. The pipe insulation was originally installed as half-round sections and the fabric was intended to function as a covering and normally would have been painted to seal the installation. The pipe insulation sections contained both amosite and chrysotile. For reasons unknown, workers had removed the fabric covering before installing the pipe insulation sections and had taken the fabric home. At the residence, the fabric was washed and it was reported that some of the material had been used for various domestic applications.
Pieces of the fabric were examined to determine whether any asbestos remained after the reported washing. Samples of the fabric were then examined using a vibration treatment to determine the extent to which asbestos fibers could be dispersed into the air. The measurements were used to predict the maximum exposure of an individual performing the reported activities
A Critical Methodological Contrast Between the Recent Japanese Industrial Standard JIS A 1481 March 2006 ‘‘Determination of Asbestos in Building Material Products’‘ and the American EPA- 600/M4-82-020 Dec 1982 ‘‘Interim Method For the Determination of Asbestos in Bulk Insulation Samples’‘
Mark R. Hagadone, INALAB, Inc.
For nearly 20 years NIST/NVLAP Accredited American Laboratories have been analyzing bulk asbestos samples based on methodology largely developed by Dr. Walter McCrone using polarized light, often coupled with Dispersion Staining. During this time period, the EPA 1982 Interim method for the determination of Asbestos in Bulk Insulation Samples has been the primary analytical method employed for asbestos determinations in friable building materials.
This method was supplemented (not replaced) by the later EPA-600/R-93/116 method which addressed asbestos determinations in various difficult (non-friable) matrixes as well as providing methodological enhancements which substantially improved the precision and accuracy of those analytical determinations. These methods are generally considered to be sufficient for the detection of asbestos in building materials down to concentrations of approximately 1% by weight, the current EPA definition for an Asbestos Containing Material (ACM).
Recently, Japan has developed its own methodology for the determination of asbestos in bulk building materials purportedly down to a 0.1% concentration by weight. This methodology is based upon a combination of phase contrast microscopy (PCM), dispersion staining, particle extinction determination, and x-ray diffraction. We will analytically contrast the essential elements of the American and Japanese methods.
Problem Solving in the Microscopy Lab of a Polyester Resin and Fiber Manufacturer
Stan Hovis, Wellman, Inc.
Working in the microscopy lab of a polyester resin and fiber manufacturer is much more than acquiring pretty digital images or, mundanely, measuring fiber birefringence. To really succeed in assisting manufacturing, research and development, technical service, and sales; the microscopy lab must solve difficult problems. The problem solving requires the lab to be well rounded. In addition to optical, electron, and fourier transform infrared microscopy, the lab benefits from the (1) knowledge of materials engineering fundamentals – such as fractography and polymer thermal properties, (2) possession of particle manipulation and cross sectioning skills, and (3) willingness to apply a detective’s approach. This presentation is focused on some of Wellman’s more interesting problems and their resolution.
Microscopy in the Pulp and Paper Industry
Wendy Cheng, International Paper
Microscopy is one of the most useful analytical techniques for analyzing paper process and product related issues in the pulp and paper industry. Our microscopy laboratory at International Paper is fully equipped with state-of-the art optical microscopes, scanning electron microscopes, X-ray analyzers, and various instruments for sample preparation. In this presentation, I will give examples of how we perform reverse engineering of various paper and paperboard products; identification of paper contamination and papermachine deposits; product defect analysis; and characterization of pigments and fibers using different microscopical techniques. The microscopy findings are valuable for supporting new product and process development. They are also critical for resolutions of mill operation upsets, field product quality issues, and customer complaints.
Investigation and Mitigation of Fumed Alumina Processing Problems
Kevin Boto and Soundar Kumaran, Cabot Corporation
One of the products that Cabot Corporation produces is fumed alumina for a variety of end users. This material consists of elongated, branched, ‘‘fractal’‘ particles (aggregates) of ca. 200 nm equivalent spherical diameter, and with high surface areas, 55 to 100 m2/g, depending on grade. An end user had reported filtration problems with dispersions made from one of our alumina products. This paper describes how polarized light microscopy (PLM) was used to determine that unwanted formation of alpha alumina particles was the main contributor to the filtration problems. A PLM method was then developed to screen the product prior to release.
Estimation of Nanoparticle Size Using Bet Surface Area Analysis
Richard S. Brown and Greg Thiele, MVA Scientific Consultants
Samples of nanoparticles were chosen from a variety of industries and were simply identified as nickel, carbon, titanium di-silicide (TiSi2), and tantalum. Samples were analyzed using a Micromeritics TriStar 3000 gas adsorption instrument which calculated a BET surface area. From this, an average particle diameter was calculated assuming nonporous spherical particles and a theoretical density of the individual materials. The equation for calculating the average particle diameter in nano-meters is 6000/(BET surface area in m2/g) x (density in g/cm3). Particle size was measured directly by transmission electron microscopy (TEM). The BET surface area and the average particle size results, as determined by TEM, correlated well within the same order of magnitude) and suggests that BET surface area analysis is a useful way to estimate the primary particle size of nanoparticles.
The Analysis of Various Types of Disposable Plateware
Walter J. Rantanen, Integrated Paper Services
This examination covers a number of different types of disposable plates, bowls and some food containers. They vary from the traditional paper plate to those that are all plastic or Styrofoam with some composites in between. The microscopical analysis examines the composition and structure of these products. The range of materials used can be interesting and sometimes unusual.
D. Scott Aldrich, Ultramikro, LLC
The United States Pharmacopeia is an annually revised compendium of methods, product and drug monographs, guidance chapters, and reference standards for the pharmaceutical industry. It is published in concert with the National Formulary, a reference for pharmaceutical formulation. The USP provides and revises standards for pharmaceutical products in Chemical, Biological, Microbiological and Physical categories. The 2007 versions are USP 30 and NF 25. Several official chapters are of primary interest for pharmaceutical physical stability and particulate matter issues; <1> Injections, <381> Elastomeric Closures for Injections, <788> Particulate Matter in Injections and <789> Particulate Matter in Ophthalmic Solutions. Many monographs and reference standards are maintained. The related quarterly publication Pharmaceutical Forum publishes letters, comments, and proposed revisions to chapters and monographs, seeking public dialogue. The presentation will provide an overview of the USP organization, industrial and expert contributions, and the subject matter in the current version.
Chemical and Forensic Microscopy
Problem Solving: Analysis and Synthesis
Mark E. Palenik, Microtrace, LLC
In chemistry, analysis is defined as the separation of a material into its basic components or elements for the purpose of identification. A variety of instruments and techniques are available to perform this function; however, the information derived from these techniques alone often does not satisfactorily answer the problem at hand. It is only by assembling the individual pieces of data obtained by analysis into a new usable form, a synthesis, that the full answer is revealed and the problem can be solved. A case study is used to demonstrate how the process works.
Use of Morphology, Micrometry, and Mass to Accomplish Brand Identification of Reloading Smokeless Powders
Smokeless powder is a common low explosive used in the construction of pipe bombs. Oftentimes bombers use reloading smokeless powders from canisters rather than remove the powder from ammunition cartridges, which is a very labor intensive activity. Ample powder remains when a device is rendered safe or when a low-order explosion occurs. While many methods use chromatography combined with spectroscopy, this presentation examines the combination of morphology, micrometry, and mass to characterize reloading smokeless powders for brand identification.
Using morphology of the particles, measuring the various dimensions of the particles (micrometry), and obtaining a collective average mass can either reduce the brand possibilities to a small number or to a single brand. After placing the powder into a morphological category, the appropriate dimensions (and sometimes mass) are entered into a statistical program to reduce the number of possibilities. If needed, a side-by-side low-power visual comparison of the questioned powder with a few suspected brands with the questioned sample may be required to provide a single brand or reduce the candidates to a small list of possible brands. This information will be useful as investigative information early in an investigation or for adjudication of the case.
Allotropes and Polymorphs; The Importance of Geometry
Jeff Hollifield, Micro Analytical
The molecular geometry of a substance is extremely important in determining how it behaves chemically and in predicting what physical and optical properties it will exhibit. For the analytical chemist, varying geometries of substances that are otherwise identical can be an advantage in determining more precisely the form of a substance and under what conditions it originated. Geometry-related terms will be defined, examples of allotropes and polymorphs will be described, and optical techniques for differentiating them will be discussed.
What’s Your Handle? A Brief Look at the Wood Used in Common Hand Tool Handles
Jason Beckert, Microtrace, LLC
This talk will focus on the wooden handles from a variety of commonly encountered hand tools. Utilizing basic microscopical wood identification skills, the wood from these handles will be identified. Different tools require different properties from their handles and these requirements dictate which woods are suitable for particular tools. Both older and newer tool handles will be examined to see how the selection of woods has changed over time.
Oblique Illumination: A Forgotten Technique?
Jan Hinsch, Leica Microsystems
In the early part of the 20th century, the ‘‘Large Illumination Apparatus after Abbe’‘ was part of just about any of the advanced compound microscopes. In this type condenser, the aperture diaphram was adjustable in diameter and decenterable to achieve oblique illumination. With many contemporary condensers, satisfactory oblique illumination can be achieved by trivial modification. This presentation attempts to show that oblique illumination still has a place in the arsenal of instruments of the contemporary microscopist.
This White, Lead-Based Paint Really Does Contain Barite: PLM & SEM-EDS
Frank S. Welsh, Welsh Color and Conservation, Inc.
The authentication of paintings involves a process that includes many aspects of research and analysis, one of which is the examination of pigments. One such case study involves an oil painting on canvas that appears to be in the Spanish genre of the 16th century. One of two samples submitted for analysis was a small piece of canvas cut from the return edge of the stretcher showing only a white ground paint. A small amount of the paint was sampled and analyzed with the polarized light microscope (PLM). Only two white pigments were identified: white lead (lead carbonate) and barytes (barium sulfate). Dispersion staining was decisive in the identification of the barytes. However, the client requested SEM EDS confirmation of the barytes because its presence would indicate that the painting could not be earlier than the very late 18th century-to-early 19th century, which is when the pigment (both natural and artificial) was first used in association with artists’ paints. The results of the SEMEDS analysis identified the presence of lead, carbon, oxygen, barium, and sulfur. However, because of the overlapping energy peaks of lead and sulfur at 2.3 keV, the peak for sulfur was not always apparent. This paper will examine and demonstrate why, in this case PLM and SEM-EDS are useful for identifying barytes and for providing evidence to help date this painting.
Microspectral Analysis of Colored Glass Fragments
Mike Eyring, Paul Martin, and John Hoang, Micro Forensics Institute, Ltd., CRAIC Technologies, Arizona Dept. of Public Safety
Microspectrophotometry (MSP) has not been generally applied to the forensic analysis of glass fragments or colored gems for a variety of reasons. Glass fragments are usually of nonuniform shape and thickness, they are relatively large for typical MSP setups, and the refraction of light from their irregular air-interface surfaces makes reproducible or comparable results almost impossible to produce. Casework involving numerous mixed collections of similarly colored glass particles has led to a need for a sorting technique to help minimize analytical time without altering the particles. A well-slide immersion technique was originally developed to sort mixtures of colorless glass particles by dispersion staining observation. This well-slide technique had been modified to allow the MSP based, UV-VIS, discrimination of some natural vs. synthetic gemstones and was previously reported by Martin and Eyring. Cargille refractive index (RI) liquids were used to closely match the RI’s of the gems in that work. Those liquids suffered from UV light induced breakdown and led to the need for frequent liquid replacement. The current work on glass fragments has shown that close RI matching of glass or gem fragments to their immersion liquids is not necessary. Glass fragments have been mounted in non-fluorescing Cargille immersion oils that are UV insensitive and within about 0.08 RI units of the glass RI. Refraction effects have not been an issue. The MSP results presented in this talk will be compared with Auto GRIM (Glass Refractive Index Measurement) and SEM-EDS results produced from the same glass fragments. The relative usefulness of the analytical techniques will be shown.
World’s Worst Microscopy
Brian J. Ford, Gonville and Caius College, Cambridge University
Once again Brian presents some examples of poor microscopy from around the world, and concludes (as before) with some great achievements in bringing microscopy to the public.
Photons, Art, Crepusculations, and Images: How Many Photons Do We Need To Make an Image?
Bill C. Mikuska, Microchem Consulting, LLC
Newton, probably the first amateur to pay attention to scientific reality, noticed that scientists cannot understand the world unless they perform experiments. As a result of his work, he suggested that light is particulate; and this insight helps us now understand the way nature may be. This paper will begin to demonstrate to the microscopist the classical and quantum mechanical aspects of light’s interaction with materials.
An Evaluation of Kevlar Fibers as a Bullet Recovery Medium
Peter Diaczuk and Meghan Miller, John Jay College of Criminal Justice
Firearm examiners base their comparisons on the minute marks imparted on bullets as they travel down the barrel of a gun. To perform a comparison between questioned and known bullets, the forensic scientist will test fire a firearm and recover the bullets. The gradual deceleration of bullets with the expectation of microscopical analysis is not a trivial matter. Historically, various methods and materials have been used to safely recover bullets that are test-fired for use in comparison microscopy.
It is crucial that the recovery medium neither create any marks of its own on the bullet, nor remove or mute any marks created by barrel imperfections. This evaluation involves a microscopical analysis of bullets fired into a new recovery material, shredded Kevlar fibers, as compared to bullets fired into traditional recovery materials such as cotton or water.
Dr. Thorndyke to the Rescue
Skip Palenik, Microtrace, LLC
The solution of the Hummert Murder Case in York, Pennsylvania in 2006 depended, in part, on the examination of small soil stains on the victim’s stretch pants. Her corpse was found stuffed in the back of her Land Rover in a supermarket parking lot. The police suspected that her husband had committed the murder, changed her clothes, and then dragged her across their driveway before stuffing her into her vehicle and driving her to the store early in the morning.
The quantity of soil on her pants was very small and attempts to compare the soil by two laboratories, before we became involved, resulted in the loss of most of this evidence. In spite of our initial skepticism that enough soil could be recovered from the clothing for a comprehensive comparative analysis, we were able to recover enough of the soil for our analysis, along with a considerable number of fibers from the pants. Although the fibers proved to be of considerable importance as well, their presence was a major impediment to the conduct of the petrographic comparison. A little known technique, employed by R. Austin Freeman’s medico-legal expert, Dr. John Evelyn Thorndyke in 1922, was used to separate the mass of fibers from the minute quantity of fine soil.
The silt sized heavy mineral suite of the minute sample turned out to be amazingly large and diverse and a positive comparison was made. Hummert was convicted of the murder of his wife. The technical (and some of the anecdotal) details of the case will be described and excerpts from the Forensic Files Television episode about this case will be shown.
Identification of Synthetic Fibers by Eutectic Melting Point with Pnitrophenol
Kelly Brinsko, McCrone Research Institute
The melting point of synthetic fibers as a means of identification has been used before. However, this method has several known disadvantages: (1) the melting points for a given fiber class tend to occur over a range of temperatures, so that the melting points of some fiber classes overlap those of others; (2) many synthetic fibers melt at relatively high temperatures; (3) some classes of fiber decompose before the melting point is reached, and: (4) without a microscope, it is difficult, to determine the melting characteristics of very small fiber fragments. procedure that was published in 1956 by Donald G. Grabar and Rita Haessly uses a light microscope and p-nitrophenol as a standard organic chemical compound to obtain a ‘‘mixed fusion’‘ eutectic melting temperature with thirteen synthetic fiber types. presentation will revisit their technique and include many new fibers that have been introduced in the last fifty years.
Utilizing Detrital Heavy Minerals for Geochronology and Source Rock Prediction
Jack Hietpas, Syracuse University
This talk reviews the utility of detrital heavy minerals isolated from both modern and ancient sediments for the timing of thermotectonic events as well as rock. This review will primarily on geologic provenance investigations however the same principles are easily applied to forensic investigations and geosourcing applications. To illustrate these principles, preliminary data derived from modern river alluvium collected from the French Broad River and its tributaries will be presented. This work is part of an ongoing research project assessing the strengths and limitations of detrital zircon-based provenance studies.
Matching Matches: Part 3
Thomas J. Hopen, Chris Taylor, Larry Peterson, and Walter Rantanen, ATF Forensic Science Laboratory, US Army Criminal Investigation Laboratory, Georgia Bureau of Investigations, Integrated Paper Services
Matching Matches, Part 1, was presented at INTER/ MICRO-2003 and this presentation dealt mainly with the examination and comparison of paperbook matches based on their physical characteristics. Part 2 was presented last year by Walter Rantanen, Integrated Paper Services, where he addressed the examination, identification, and comparison of the paper fibers from the match stems. Part 3 will address a supplemental physical feature useful when conducting a match examination which was not addressed in Part 1. Also, Part 3 will discuss examination and comparison of matches by PLM, SEM-EDS, XRF, TLC, microspectrophotomety, as well as use of Photoshop® in the comparison of the match stem color.