Wood Identification Workshop
Walter J. Rantanen, Integrated Paper Services, Inc., substituting for Regis B. Miller, Ph.D., Forest Products Lab, retired
Wood identification depends on the morphological characteristics of wood cells revealed by the microscope. This full-day workshop, designed by wood anatomy expert Regis Miller, explored the use of hand lenses and compound microscopes for identifying various North American hardwoods and softwoods. Participants in this workshop learned how to make small thin-sections and microscope slide preparations to explore the anatomical features observable at low and high magnification. Regis is frequently consulted in forensic cases where wood evidence is collected. Those who participated in the ‘Wood Identification Workshop’ were presented with a certificate of successful completion by McCrone Research Institute, Chicago.
(Because Professor Miller was unable to attend due to an injury, Walter Rantanen conducted the workshop.)
Paper Fiber Identification Workshop
Walter J. Rantanen, Integrated Paper Services, Inc.
This full-day workshop, conducted by paper-fiber expert Walter Rantanen, concentrated on many of the same species of wood, hardwood and softwood, presented by Dr. Miller in the earlier Wood Identification Workshop. The concentration focused on the microscopy of common types of wood and fibers used in the paper industry. Walter is frequently consulted in cases of fiber source determination and methods of processing (mechanical, chemical, sulfite, Kraft, etc.). Participants in this workshop learned how to use reference paper pulp slurries to make microscope slide preparations for their own use. Those who participated in the ‘Paper Fiber Identification Workshop’ were presented with a certificate of successful completion by McCrone Research Institute, Chicago.
Techniques and Instrumentation
Know Your Tool An Investigation Into the Unwanted Side Effects of Using Commonly Available Image Processing Software to Handle Electronic Images
Richard S. Brown, MVA Scientific Consultants, and Ben Zipperer, Sugarloaf Tech
Scanning electron microscopes with digital X-ray imaging capabilities produce electronic image data in file formats that can be processed using widely available commercial and open-source image processing programs. When these images are displayed on a computer screen they appear to be similar to monochrome optical photographs. It is important to remember, however, that for quantitative analysis the pixel data in these images is directly correlated to a specific physical quantity such as the concentration of an element. Quantitative errors as much as 5% to 10% can easily be introduced into this data by the nave use of software (such as Photoshop) which was designed for processing and publishing optical photographs in a manner consistent with the visual response characteristics of the human eye. An investigation into the errors introduced by procedures and processes commonly performed using such software, was performed.
A New Standard System for Establishing the Performance of an Automated Electron-Beam Particle Analyzer
Frederick Schamber, ASPEX Corporation
An automated electron-beam particle analyzer is a powerful tool for studying populations of particles. Due to the growing importance of assessing micron-scale particulate contaminants in regulated industries, such as pharmaceutical manufacturing, there has been an urgent need for a simple yet reliable means of assuring that such measurements are performed accurately and consistently. Previously available standards have not been suitable for this task for many reasons, but a particular problem is associated with the inevitable accumulation of foreign particulate material on any specimen handled in a normal laboratory environment. A new particle standard system (patents pending) has been developed which addresses the specific challenges of this type of application. The special specimen, fabricated by semiconductor-type lithographic techniques, simulates a filter membrane loaded with low-atomic number particles of precisely known size, shape, location, and composition. A software component matches the particles identified in a measurement of the specimen against the database of known features. From this match, accurate measures of parameters such as false positives and false negatives, magnifications accuracy, and sizing precision are automatically extracted. A comprehensive report is generated which provides a ‘pass/fail’ assessment of the instrument’s performance.
A Portable Microscope From Poland
Brian J. Ford, Gonville and Caius College, Cambridge University
An amateur Polish microscopist has produced prototypes of a portable field microscope. The design has many advantages over earlier essays in this field, and Brian will present an account of the work and show photographs of the microscope in use. In many ways it is a remarkable tribute to the amateur hobbyist and could point to a viable design for commercial exploitation.
An Overview of the Ring Oven
Publications on the use of the ring oven first appear in the mid 1950s. The original monograph Microanalysis by the Ring Oven Technique was published in 1961 with 26 literature citations. By the second edition, in 1970, there were over 200 publications in the literature covering a wide variety of analyses. Analyses included cations, anions, organic compounds and radionuclides, all using the ring oven technique. The ring oven was also combined with other methods such as electrography, paper chromatography, thin layer chromatography, and ion exchange to expand its applications.
Publications on the ring oven peaked in the 1970s and tapered off at the end of the decade. By the 1980s, only a few publications appeared. The ring oven was primarily a qualitative microchemical technique and functioned as a modification of spot tests to improve their sensitivity by separating and concentrating the analytes into narrow bands. It also allowed for multiple tests on a single band with a variety of reagents. Despite these advantages, the advances in electronic instruments for qualitative and quantitative analysis, like the atomic absorption spectrometer, ended the reign of the ring oven as an analytical tool.
Although difficult to find these days but not impossible to build, the ring oven remains a useful tool for those scientists doing microchemical and spot test analysis on small samples.
Recent Activities of the Georgia Microscopical Society
Randy Boltin, MVA Scientific Consultants
Consultants The Georgia Microscopical Society (GMS) was formed in 1988 as The Georgia Microscopical Study Group. The Society was formally incorporated in 1993. Over the years, GMS has hosted such distinguished speakers as Dr. Walter McCrone, founder of McCrone Associates and the McCrone Research Institute, Martin Scott, Senior Biomedical Imaging Specialist with Eastman Kodak Co. and founder of Scientific Imaging, and Brian Ford, renowned scientist, lecturer, broadcaster, and author. Lecture topics have ranged from Leeuwenhoek’s simple microscopes to telescopes.
The GMS began teaching a Young People’s Microscopy course in 1984. Thom Hopen, former instructor at the McCrone Research Institute, was instrumental in putting together this course, which was modeled after the State Microscopical Society of Illinois’ course in which Mr. Hopen also participated as an instructor. Course topics include an introduction to the microscope and its history, polarized light microscopy, chemical microscopy, classification of organisms, rocks and minerals, forensic microscopy, electron microscopy, and digital microscopy.
In 2005, GMS instituted the Walter C. McCrone Student Science Award. This award recognizes students who have incorporated microscopy as an integral part of projects accepted for exhibition at the Georgia Science & Engineering Fair. Separate awards were given for the Junior (7th and 8th grade) and Senior (8th through 12th grade) divisions in 2006.
Elementary Microscope Calibrations, Measurements, and Calculations
Jan Hinsch, Leica Microsystems
Early microscopists already strived for quantitative descriptions of objects under the microscope: ‘this last kind of animal is a thousand times smaller than the eye of a large louse’ reports Leeuwenhoek according to his biographer Paul de Kruif who goes on to say that the eyes of adult lice are remarkably consistent in size. This paper traces some of the progress that has been made since then from the eyepiece reticule to more recent ways of measuring length, area, volume, depth, angle, retardation, and many other properties by computers and software. The first step to precise measurements is the calibration of the microscope and this paper deals with empirical as well as automated methods that are part of digital microscopes.
Microscopy at Home: The Top Ten Reasons Why it Pays to be a Microscopist
Andrew A. Havics, pH2, LLC
It seems that every microscopist takes a piece of their work home with them often resulting in a home lab. As the labor of love progresses, so does the size of the home lab, and the size of the challenges to be tackled. Inevitably, similar to the workplace, the resistance from others to having a home lab fades as the benefits are seen to clearly outweigh the trifling cost. A top 10 list of these reasons/benefits to being a microscopist at home will be presented in the form of a puzzle series. A photomicrograph of the reason will be revealed and the audience will be asked to join in to solve the puzzle as a clue or two (and perhaps more of the image) is released.
Describing Stains and Deposits: Suggestions for a Standard Terminology
Chesterene Cwiklik, Pacific Coast Forensic Science Institute, Inc.
The microscopist who is asked to identify or compare stains and deposits on other items, or to interpret alterations or damage, relies not only on the nature of the material to be tested, but also on the nature of the deposit itself. The analyst needs to know what the deposit looks like (the nature of the deposit), what it comprises (the type of material), how it got there (the manner of deposit), and what happened to it (alteration and wear). Although there is significant information from initial low-magnification observations, there is little standard terminology for describing stains and deposits. Terminology used to describe soil deposits, accretions in metal conduits, and defects in paint coatings are a useful beginning, but are far from comprehensive. Suggestions for terminology presented in this paper, drawn from descriptions of stains, deposits and damage to clothing items in forensic science casework, are offered in the hope of stimulating the development of a comprehensive standard vocabulary.
Broad categories of types of deposits and damage to be described include: 1.) stains, spatter and any change in luster or sheen; 2.) crusts, films, accretions and gummy deposits; 3.) dust, powdery matter, aggregates of particles, residues, debris; 4.) cuts, tears, punctures and other holes; 5.) melting, color change or change in luster that might indicate thermal, mechanical, chemical and biological damage; and 6.) direction and sequence of damage and deposits.
A checklist is suggested for recording observations and preliminary conclusions, including a.) description of stain, deposit or damage; b.) how the sample was deposited (smeared on, stuck in, loose, originally liquid, originally dust); c.) whether mixed in/deposited on/wadded up with other materials; d.) whether a stain is visible, or detected chemically; e.) whether a stain or deposit is part of a pattern; f.) whether damage appears recent or not; and g.) whether stains and deposits appear recent.
A standard terminology is not only a matter of convenience, but should stimulate attention to the information resident in macroscopic observations of stains and deposits, so that even inexperienced examiners would have a reference, and scientists who are not principally microscopists would have a tool for conveying information that might otherwise be lost.
A Study of the Diagnostic Microtextures of Quartz
Sebastian Sparenga, McCrone Research Institute
Is it possible that one of the most common minerals can be a source of valuable information in an investigative analysis? Using 15 microtextures for comparative purposes, more than 300 quartz grains from several depositional environments were studied by stereomicroscopy, polarized light microscopy, and scanning electron microscopy. By noting the microtextures and general morphology of the grains, the capability of determining the transport history of the grains will be explored.
Characterizing Organic and Inorganic Materials Using Automated Electron-Beam Particle Analyzers and Energy Dispersive Spectroscopy
Timothy Drake, ASPEX Corporation
Particle characterization has enormous importance to many industries. The majority of the instruments used for particle analysis are based on photon technology. Though such instruments have many virtues, the wavelength of light and the physics of photon interactions impose fundamental limits on the extension of these techniques. As industrial processes become increasingly concerned with the morphology and composition of ever-smaller particles, there is a growing need for new approaches. Scanning electron microscopes are often regarded as the instruments of choice for imaging and elemental characterization of microscopic entities; however traditional implementation of such instruments are not well-suited to routine analysis of particle populations.
However, over the last decade, efficiently automated instruments have been developed which operate unattended, are cost-effective for routine analyses, and are now being adopted for diverse industrial applications, including pharmaceutical quality control, automotive critical-cleanliness, and steel making. Particles commonly characterized are made of inorganic materials which have atomic number contrast higher than that of organic-based filters. In this work, organic as well as inorganic particles were analyzed using a metal-coated filter with varying pore sizes which were as low as 0.2 Âµm. Although energy dispersive spectroscopy will not be able to give detailed identification of carbon based materials, the spectra of organic particles can differentiate different types of particles based on oxygen content as well as inorganic elements in the molecular formula of the organic particles, such as metallorganics or F, P, S, Cl complexes. Samples were investigated to provide total particle counts, elemental signatures, particle types, size distributions, and the shape distributions based on single particle characterizations.
A Revival of Chemical Microscopy Using the Infrared Microprobe
John A. Reffner and Pauline E. Leary, Smiths Detection
Mid-infrared spectroscopy is bringing renewed interest and extended applications to chemical microscopy. Extracting and confirming chemical identity of objects seen with the light microscope is an innovating and rewarding scientific experience. The results of micro-crystal tests used for illicit drug analysis are documented and confirmed by recording their infrared spectra. Minerals in rocks are seen and their chemistry is disclosed by the infrared spectra. When I see a diatom, I immediately know more about this material than its chemistry. Infrared spectra will not distinguish corn starch from wheat flour. On the other hand, determining optical crystallographic analysis of a new drug will not disclose its molecular chemistry. There is a new world of chemical microscopy. Its foundation is solid; its future is bright.
So Many Particles, So Little Time
Gary J. Laughlin, McCrone Research Institute
Microscopists are often believed to be able to recognizes all solid substances from any origin: animal, vegetable, mineral, or other. However, chemists tell us that there are several million known inorganic and organic solid substances. Mineralogists have identified just over 4,000 known minerals. Biologists know that there are over 100,000 species of fungi and far more protists, plants, animals, and bacteria that together comprise or make up countless numbers of microscopic cells. How does a microscopist learn to identify so many particles in his/her lifetime? This talk will discuss a reasonable solution including starter lists of particles that any student, amateur, or professional should know, including selected substances gleaned from forensic, industrial, environmental, and chemical categories.
Novel Applications of Cathodoluminescence Microscopy
Christopher Palenik, Microtrace
Cathodoluminescence (CL) refers to the emission of visible (or near visible) light from a sample that has been bombarded by an electron beam. This luminescence originates from defects and/or impurity atoms (e.g., rare earth elements) in semi-conducting inorganic materials. These materials include many commonly encountered minerals such as quartz, feldspar, and zircon as well as many industrial materials that contain inorganic fillers such as pigments, paint, glass, flyash, and duct tapes. This talk will provide an overview of the equipment and analytical concerns of CL as well as ways in which CL can be used to supplement information provided by polarized light microscopy. This includes the screening of geological samples to quickly identify the major mineral components, the differentiation of various samples on the basis of luminescence, and the use of luminescence to provide constraints on the environment from which a sample originated.
Evening with Brian: How Tomorrow’s Lifestyle Fosters Yesterday’s Pestilence
Brian J. Ford, Gonville and Caius College, University of Cambridge
Microscopists are regularly reminded of the recurrence of age-old pests and diseases. Currently there is a raft of food-poisoning outbreaks that are related to modern practices, and pests that we once thought vanquished are re-emerging as a hazard for people on the latest style of vacation. The modern world is meant to be ending scourges of the past, but in many ways is fostering their re-emergence. Tonight, Brian will demonstrate the point with some eye-catching examples causing concern.
Environmental and Industrial Microscopy
An Organizational Chart to Guide Sample Preparation for Polarized Light Microscopical (PLM) Analysis of Bulk Samples for Asbestos
Bharati Lakshmi and Mary Helen Scott, Marine Chemist Service, Inc.
A microscopist in an asbestos laboratory analyzing bulk samples for asbestos by PLM encounters a variety of samples on a daily basis. In this analytical method, sample preparation is a very important step in sample analysis. One slide preparation technique definitely is not suitable for all samples. Recognizing this limitation, NVLAP (National Voluntary Laboratory Accreditation Program) requires the laboratories to have written procedures for dealing with samples ‘in which the fibers are heavily coated with binders that hinder analysis’ and ‘that are semi- or non-friable.’ Generally PLM laboratories prepare lengthy procedures separately for each type of material like floor tile, roofing, ceiling tiles, etc.
Here we describe a chart that combines various methods suitable for different types of bulk samples generally received by an asbestos laboratory. This chart encompasses a variety of samples and procedures for preparing those samples that work best on the nature of this binder. This chart is concise and easy to read and follow. It can also be used to train new analysts in sample preparation techniques. Additionally, the ‘Comments’ Column gives hints about the nature of sample and what type of material can be expected to contain asbestos and how to examine the sample.
Dust Sample Analysis Problems
Randy Boltin, MVA Scientific Consultants
Challenging situations are often encountered while attempting microscopical characterization of particles in dust samples. Every living creature or inanimate object that enters a building or that encounters wind currents on the upwind side of a structure is a potential contributor to particulate accumulation in the indoor environment. A wide variety of particle types from multiple sources is thus potentially generated.
Many interior dust deposits are characterized by components that mark them as “typical” indoor, or household, dusts. Even these often-encountered deposits consist of mixtures of particles exhibiting a broad spectrum of physical and chemical properties. Floral, faunal, mineral, and synthetic particle types are all commonly found in a single dust sample. Both sampling and analysis of such heterogeneous particulate deposits can be problematic.
Uneven collection of particle types exists among the various mechanisms used to obtain dust samples. Microvac sampling of dust containing a substantial population of biofilm, adhesive, or charge-bound particles can result in underestimation of the amount of such particles actually present. Tape lift or wipe samples may yield a more accurate representation of relative abundance of the particle types constituting a sample. Tape sampling is probably the most effective at obtaining a complete sampling of dust particles from a surface but often will collect substrate material as well. An additional problem with tape is that observation of the physical and optical properties needed for accurate identification of many particle types can not be accomplished while the particles are attached to the tape. Wipe sampler substrate composition can interfere with the analysis. Ultimately, examination of adjacent samples taken using different sampling methods yields the most complete picture of the relative distribution of dust components.
Once a satisfactory sample is obtained, a number of obstacles may occur. Some common situations include: (1) Artifacts from sampling utensils can potentially be misidentified as constituents of dust. (2) A variety of fine, opaque black particles can be found in dust. Such particles require observation in reflected light, manipulation testing to determine deformation characteristics, and sometimes further characterization using alternative instrumentation to confirm their identity. (3) Some constituents may be soluble in, or have the same refractive index as, a particular mounting medium. In the former case the constituent will not be present; in the latter, it may be more difficult to detect and its relative abundance underestimated. Multiple mounting media should therefore be used in the examination of dust particles. (4) Relative abundances should be expressed accurately but should not be misleading. For example, fungal spores may occupy <1% by volume of a sample but may be numerically abundant and this information should be conveyed to the client.
Amphibole Asbestos and Nonabestiform Amphibole: Does Either Morphology Exist Without the Other?
Eric J. Chatfield, Chatfield Technical Consulting Limited
A water elutriation method has been applied to separate the respirable fraction from parallel samples of crushed amphibole asbestos and crushed nonasbestiform amphibole of similar compositions. The respirable fractions were examined by TEM to determine the lengths and widths of the amphibole fibers longer than 5 Âµm. It appears that, even for well-characterized crystals of non-asbestiform amphibole, a small proportion of the fibers generated by crushing these crystals have widths smaller than 1 Âµm and aspect ratios higher than 20:1. The amphibole associated with some commercial minerals has been shown to include amphibole fibers with dimensions that could be classified as asbestiform. The continuing controversy concerning discrimination between asbestiform and non-asbestiform amphiboles at the microscopical level will be discussed.
Light & Electron Microscopy of Mineral Wool Fibers
Richard S. Brown, Bryan Bandli, Randy Boltin, and Bill Turner, MVA Scientific Consultants
Mineral wool fibers are routinely encountered in environmental dust samples due to their use in building insulating materials, fireproofing, and ceiling tiles. The characterization of mineral wool fibers is performed utilizing a combination of polarized light microscopy (PLM) and scanning electron microscopyenergy dispersive X-ray spectrometry (SEM-EDS). Recent attempts to classify mineral wool fibers by their elemental composition based on dusts examined as a result of the World Trade Center disaster have led to an incorrect classification of some mineral wool fibers as slag wool. Mineral wool fibers consist of slag wool and/or rock wool. Their respective optical properties, thermal properties, and elemental compositions are the result of the ingredients used by a manufacturer at the time the mineral wool product is produced. Slag wools may contain iron, zinc, copper, lead, and manganese depending on the source of the slag used. Rock wools may or may not contain iron and other heavy elements, depending on the raw materials incorporated into the manufacturer’s formulae. Products from different manufacturers have been characterized using PLM and SEM-EDS and the results show a large variation in the elemental compositions amongst products termed slag wool and rock wool. This makes the classification of a mineral wool fiber (as either slag or rock wool) difficult if not impossible, based on the overlap of elemental composition and optical properties amongst the mineral wool products available.
A New Application of the PCM Method Used for Asbestos in Air Samples to Prepare Reference Slides for Mold Spores
Bharati Lakshmi and Gillian Jones, Marine Chemist Service, Inc.
Environmental microbiology laboratories are required to identify and count mold spores during nonviable spore trap analysis. It is desirable to have a set of reference slides to facilitate mold spore identification. Here we report a simple method for making permanent slide mounts of mold spores.
Frequently, during the air sample analysis for asbestos fibers by Phase Contrast (PCM) technique (NIOSH 7400), we notice mold spores. These observations prompted us to prepare mold spores collected from known fungi following the method used in PCM analysis. The spores were lightly spread on the Mixed Cellulose Ester (MCE) filters taken from PCM cassettes. The filter was cleared using acetone vapors injected through a ‘Quick Fix’ commonly used in asbestos laboratories. Later, the filters were mounted in triacetin. Slide mounts of materials containing spores like Chaetomium sp., Stachybotrys sp., and basidiospores showed very good resolution. These slide mounts can be easily stored for long periods of time.
This technique provides an easy and simple method for laboratories currently analyzing asbestos by PCM to make a collection of known mold spores to be used as reference slides.
Analysis of Outdoor Airborne Mold Flora
Ghulam Rabbani and Albio Marquez, STAT Analysis Corporation
Humans have evolved in harmony with mold flora in the environment. Indeed, normal environmental mold flora is a sign of a balanced ecosystem. However, health problems may sometimes arise as a result of unusually high numbers of airborne mold spores or due to the presence of mycotoxic or pathogenic mold in the environment.
Outdoor air mold flora varies over diurnal and seasonal cycles. Geographic location, microclimate, and the surrounding vegetation also influence the total number, proportion, and type of mold flora in the environment. Certain mold spores can multiply within susceptible human hosts and in indoor environment conducive for their growth, which in turn can lead to other health hazards and can trigger allergic reactions.
In the present study, the fungal flora in the outdoor air in the Chicago area has been characterized through the analysis of air samples over three years. This study may be useful for evaluating normal versus problem environments and assessing the risk.
Microscopy of Taraxacum-Learning From Experience
Brian J. Ford, Gonville and Caius College, Cambridge University
The familiar dandelion, Taraxacum, can modify its growth pattern in the light of experience. The plant exhibits memory, which can persist for many months. In this illustrated presentation, Brian relates how the plant responds to memories of previous experiences and reveals how microscopy can disclose the mechanisms responsible for the morphological change observed in the mature plant.
Investigation of Problems Caused by Darkening Agents
J.R. Millette, W. Turner, Jr., W. Hill, P. Few, and J.P. Kyle, MVA Scientific Consultants
The investigation of dark contamination problems on the surfaces of buildings and outdoor facilities relies on microscopical analysis. The ASTM Standard D6602 provides a framework for sampling and using both light and electron microscopy to classify the particles involved (the darkening agents). The darkening agents may be biological (mold, algae, bacterial deposits), soil minerals, black carbon (BC) such as soot, or carbon black. This paper presents information about identifying the various types of contaminants that might be the cause of a dark appearance on an outdoor surface.
Chemical and Forensic Microscopy
Confocal Laser Scanning Microscopy (CLSM)
John Dale, Imperial Chemical Industries
Imperial Chemical Industries, in the United Kingdom, has a long history of problem solving using applied microscopy techniques. A brief introduction to the historical use of microscopical techniques in ICI will be followed by a review of the development of Confocal Microscopy as an analytical tool. The use of confocal microscopy as a problem solving and research tool in materials science will be discussed and set within the context of a busy micro-analytical laboratory.
Some Microscopical Methods for Modeling Macroscopic Crystallization Systems
Michael Bayard, Bayard Development Company
Over the past few decades, microscopy based methodology and devices have been developed that have successfully predicted trends in industrial scale crystallizers ranging from simple batch crystallization in stirred tanks with external cooling to the more complex continuous systems such as baffled chambers with selective fines destruction. Sizes range from a few liters to thousands of gallons. Items such as particle size distribution, morphology (favorable or unfavorable), retained liquid inclusions, phase separated impurities and materials handling characteristics can be predicted with a reasonable degree of certainty. The extension of these methods to the largest crystallizers, those with volumes measured in millions of gallons, will be discussed.
An Equine(?) Parasite Problem
Andrew A. Havics, pH2, LLC, and Anthony R. Caldwell, Animal Protection Coalition, Inc.
While engaged in Equine Protozoal Myeloencephalitis (EPM) research, investigators observed worms in the blood samples being processed. The worms were subsequently identified as strongyle-type parasites. As a result of these findings, all of the EPM research blood samples were examined for parasites. The findings showed parasitic infections at an alarming level.
A comparison of these findings showed a pattern that demanded further investigation. A large number of horses showing EPM-like symptoms tested low or negative for Sarcocystis neurona and/or Neospora infections; however, upon examination, strongyle-type parasites were present in the blood samples. The investigation into the link between EPM negative equine and neurologically deficit equine with vascular parasite infections continued.
At the onset of the investigation collection and cataloging of samples was limited to rescued equine from Indiana. The test results from those blood samples revealed a high parasitic infection level in most subjects. It was determined that this was not an adequate sampling of the general equine population, so the research was expanded to include a variety of equine from a larger geographical area. In the beginning the blood collections were limited to Indiana equine of all ages, breeds, and all ranges of facilities. The results of the analysis of the blood samples collected were comparable to the initial findings. Parasitemia was found in a wide variety of the most well kept, well maintained equine in Indiana.
The research area was increased to include Arizona, Arkansas, Kentucky, Ohio, and Texas. The analysis supported the earlier findings. Parasitemia was diagnosed successfully by the veterinarians, based on an analysis of the blood samples. The horses were treated by the veterinarians and success stories started mounting. Not only EPM-like symptoms, but a wide variety of disorders and diseases, were resolved after treatment for the parasitemia. The most devastating adverse health conditions were noted in long term, low level parasitemia.
In addition to equine at the research facility, there are canines with medical disorders. A select group from the research staff began to analyze the canine blood with the same protocol used in the equine research. The results were remarkably similar to the equine findings. Upon successful treatment of the test subjects, different levels of recovery were noted.
Unexpected Results From Analysis of Lung Tissue Samples From Two Patients
Eric Chatfield, Chatfield Technical Consulting Limited
Lung tissue samples from two patients were examined by transmission electron microscopy (TEM).
One patient had been employed by a company that produced titanium and iron from ilmenite. Asbestos exposure was alleged, but although the lung tissue contained a high concentration of ferruginous bodies, there was only a trace of uncoated amosite fibers. It was shown that the ferruginous bodies were related to ilmenite, and not to asbestos. The case was eventually classified as general dust pneumoconiousis.
Another patient had been a dentist, and had died from mesothelioma. Exposure to chrysotile for a short period during dental school training was alleged. Examination of the lung tissue showed that the patient had experienced significant exposures to both amosite and richterite/winchite. The sources of these amphibole exposures remained undetermined, but the case underlies the fact that significant exposures to asbestos may have occurred without the knowledge of a person who eventually exhibits asbestos-related diseases.
Microscopical Evaluation of the Airvoid System in Concrete
Victoria Jennings, CTL Group
To the naked eye, concrete appears to be a hard and dense material. On a microscopical level, however, it is actually quite porous. As such, it can absorb and retain moisture. If concrete is exposed to freezing temperatures while saturated, water within the pores will expand as it freezes, creating tensile stresses in the concrete. Over many cycles of freezing and thawing, the concrete may begin to crack and deteriorate.
To alleviate the stresses created by freezing pore water, and thus prevent freeze-thaw damage, air bubbles are often incorporated into concrete. These air voids provide space for the water as it expands when freezing. To ensure adequate protection from deterioration, the air voids must: 1) comprise a minimum volume within the concrete, 2) be of a sufficiently small size, and 3) have an adequately close spacing. A method for the microscopical determination of these parameters of the air-void system is provided in ASTM Standard Test Method C 457. Further microscopical examination of concrete can identify characteristics of the air-void system that may adversely affect concrete quality and performance. One such characteristic discussed in this paper is clustering of air voids within the cementitious paste and along the interface with concrete aggregates.
An Introduction to Nano Test System and Nano Indentation
Richard S. Brown, MVA Scientific Consultants
The Nano TestTM is a modular testing tool used to examine the mechanical properties of small volume samples and thin films. The tool uses a diamond probe to measure force, displacement, and time throughout indentation of a sample. The high resolution and sensitivity achieved through its unique design allows for the analysis of mechanical and tribological properties of a materials/coating system at the nanoscale. The techniques of Nanoindentation and nano-scratch will be introduced from a microscopist’s point of view.
Why is Product Appearance Important in a World of Nano-Detection?
Scott Aldrich, Ultramikro, LLC
Applied microscopy has certainly taught us an important lesson; that the value of direct observation is profound. We have also learned that using all available tools will augment the final analysis of materials; that the integration of all data is essential. Visual inspection is a common, but an often unappreciated product-improvement tool. Visual clues and macroscopic observation are sometimes overlooked in state-of- the-art analytical setting. In the evolution of instrumental capability, with increasing sensitivity and narrowing specificity, practical approaches sometimes suffer. Keeping the approach simple, and broadly inclusive, keeps us on track, in perspective, and includes all clues in the pursuit of the correct conclusion. Just as in applied microscopy, a number of inspection techniques and considerations will aid in forming the best conclusion.
Industrial inspection is conducted prior to, during and after assembly, and in the medical industries, according to defined release criteria. What we can detect is affected by our own experience, training, and attention to detail. The procedure used will affect sensitivity of detection through many parameters, but principally pace/dwell time, illumination level, and illumination color will be enhanced by product actuation or use-testing.
The presentation will review typical observational habits and insights, will focus on the importance of inspection training, and will give insights to the importance of factors affecting inspection sensitivity.
Microscopy of Building Materials at USG
Art Struss, USG Research
Microscopy is used extensively for analyzing building materials like gypsum wallboard, tape joint compound, ceiling tile, and cement board. The strength of wallboard and gypsum products is related to gypsum crystal morphology and pore structure. Retention of microstructure is critical to retaining fire proofing properties in ceiling tile and gypsum wallboard. The investigation of paint, plaster, and joint compound delamination is aided by microscopical analysis. Cement board analysis includes microscopic image analysis of porosity and the study of crystal microstructure formation. Examples of these investigations will be used to show how microscopy is used to solve applied industrial problems related to building materials.
Applied Analytical Microscopy
John Dale, Imperial Chemical Industries
Imperical Chemical Industries has leveraged the field of Analytical Microscopy for decades. This talk by an ICI Business Scientist will describe the field of Analytical Microscopy in its broadest sense. Deep scientific work will be described and placed in the context of human (customer) interaction and the resolution of problems such as contamination, the elucidation of structure property relationships and production problem solving. The position of Light Microscopy as a Key problem solving tool will be highlighted within the context of a growing ‘Chemical Imaging’ field that encompasses much more sophisticated techniques.
‘Individualizing’ Minerals: A Proposed Approach for Forensic Soil Comparison
Andrew Bowen, Stoney Forensics, Inc.
Forensic soil comparison has been an important tool in crime investigations for over 100 years. However, there has been debate over the validity of some of the techniques commonly used by forensic scientists to compare soil samples, such as density gradients and bulk elemental analysis. One method espoused by some scientists has been the use of ‘unique’ particles in a sample. However, this method depends upon the fortuitous presence of a rare or unusual particle type in either the questioned or known soil sample.
This talk will propose the use of techniques that could be used to ‘individualize’ mineral grains in a sample. They include isotopic dating techniques, morphological analyses, and trace element analyses performed on individual mineral grains. It is not suggested that two mineral grains can be ascribed to a single common source with a degree of certainty similar to that achievable for pattern evidence or biological evidence. However, it is believed that this approach would allow a higher degree of confidence to be ascribed to conclusions drawn during forensic soil comparisons than is currently possible. In addition, these methods are not affected by sample fractionation during transfer, unlike properties such as particle size distribution and bulk chemistry.
An Update on the Optical Characterization of Triacetonetriperoxide (TATP)
Jacqueline Speir, McCrone Research Institute; Jack Hietpas and Skip Palenik, Microtrace
At Inter/Micro 2005, Jack Hietpas presented research concerning the optical and physical characterization of triacetonetriperoxide (TATP). At that time, refractive indices were not measured. This talk will summarize former observations as well as provide recent updates on the continued characterization of this exotic explosive.
The Use of Microscopy in Firearm and Tool Mark Examination
Peter Diaczuk, John Jay College
The light microscope is a crucial component in the forensic analysis of firearm and tool mark evidence. An understanding of its potential is necessary to appreciate its versatility and discriminating power in physical evidence problem solving. This presentation will review applications of light microscopy in firearm and tool mark examinations, including comparison microscopy and the recognition of trace evidence using stereomicroscopy and polarized light microscopy. The angle and type of illumination, which is particularly important for impression evidence, will also be discussed. Case studies will be used to demonstrate the integration of these methods in analyzing firearm and tool mark evidence in both the investigative and adjudicative stages.
Microscopical Identification of Gunstock Wood From Selected Firearms of World War II
Jack Hietpas, Microtrace, and Regis Miller, Forest Products Laboratory (retired)
The authors present the sampling techniques, slide preparation, and microscopical characteristics present in wood thin sections which allowed for the identification of gunstock woods. To our knowledge, there have been no other published articles concerning the specific identification of gunstock woods. The identification of gunstock wood is important particularly for authenticating firearms of historic value and/or vintage. We have included military firearms from the United States, Australia, Japan, Russia, Switzerland, Germany, and England.
2, 4-Dinitrophenol: Weight Loss and Explosive
John B. Crowe, Lorrie Lin, and Mark R. Witkowski, FDA Forensic Chemistry Center
Two events helped define the Food Drug and Cosmetic Act in 1938. One involved a liquid form of the drug sulfanilamide in which diethylene glycol was used as a drug solvent. In this case, over 100 children were killed. The second involved the use of dinitrophenol as a drug promoted for weight loss. The use of dinitrophenol (DNP) resulted in numerous injuries and deaths and was removed from the market in 1938. The use of 2, 4-dintrophenol for weight loss has had a recent resurgence, due in part to its unapproved use in body building. Dinitrophenol compounds include 2, 4-dinitrophenol, 2, 5- dinitrophenol and 2, 6- dinitrophenol. These compounds are explosive materials and poisons. Evidence received at the FCC in 2005 involved a suspected selling of capsules to body builders. The evidence submitted was thought to be steroidal in nature. Subsequent analysis determined that the capsules contained 2, 4-dinitrophenol. DNP compounds are well suited for analysis by light microscopy and infrared spectroscopy. Based on optical and spectroscopic properties, 2, 4-dinitrophenol can be differentiated from 2, 5-dinitrophenol and 2, 6-dinitrophenol. The materials used to cut or dilute the 2, 4-dinitrophenol were determined as well. The optical and spectroscopic methods used in the analysis of 2, 4- dinitrophenol will be presented.
Evaluation of Nitron Sulfate as a Microchemical Test for Some Common Oxidizers
Gene Lawrence, San Diego County Sheriffs Crime Lab
The Nitron test has long been used as a color test for nitrates in the forensic analysis of low explosives. Chamot and Mason list nitron sulfate as a microchemical test for the nitrate anion. Having noted that nitron sulfate forms a precipitate with other compounds, we tested nitron as a microchemical reagent for some other common oxidizers found in low explosives. Other oxidizers we tested included nitrite, chlorate, perchlorate, and permanganate.
Teaching PLM Using Macroscopic Techniques
Bill Mikuska, SMSI
Teaching polarized light microscopy (PLM) challenges both the student and the instructor: the instructor must ensure that the student understands why operations are performed and not merely told the mechanics to get a job done. Involved are optics, polarization, pleochroism, birefringence, among optical concepts. Historically these concepts were demonstrated macroscopically by means of a simple polariscope or in this case, a viewgraph (over head) projector, or a light bench. Later came the polarized light microscope when the optical properties of smaller size substances were desired; thus, the light microscope could be made into a small polariscope or optical bench with magnifying lenses. By using a few linear polarizers, a laser pointer, hand held UV sources, colored glass filters, hand sized pink or green calcite crystals of optical quality, students can understand and study all of the properties mentioned above, in addition to fluorescence, phosphorescence, non-linear optics, and the Stokes shift.
The Use of the Microscope in Forensic Biology
Edwin L. Jones Jr., Ventura Sheriff’s Forensic Sciences Laboratory
This talk will cover the subject of the light microscope and its use in the identification of spermatozoa, saliva, vaginal secretions, and feces. The identification of sperm heads with the use of Oppitz’s stain (also known as Christmas tree stain) will be discussed. The differentiation of nucleated squamous epithelial cells from the mouth and vagina using Lugol’s iodine test for glycogen will be covered. The use of bright field transmitted light microscopy, phase contrast microscopy, and polarized light microscopy in this identification process will be discussed.
Microscopical Analysis of Check Papers
Walter J. Rantanen, Integrated Paper Services, Inc.
A microscopical examination of the paper used for checks was performed over numerous decades and from different source areas. The features of interest involved the grade of paper, fiber types, and some notes on the printing used. This was a partial survey due to limited available material. The results may imply the typical trends in what was used over the time period.
The Identification of Unapproved Materials Injected Into Human Tissue for the Purpose of Cosmetic Enhancement
Mark Palenik, Microtrace
Silicone along with a variety of other non-sterile materials injected into human tissue is being used as a means of cosmetic enhancement surgery. These surgeries are being performed by people with no medical training. Typical areas of injection are cheekbones, brows, buttocks, hips, thighs, and calves.
This case involves a woman who died eight days after having injections of a substance into her buttock area. Police suspected silicone caulk was used in the procedure. Material removed from the buttocks during an autopsy was submitted for analysis. Techniques used to identify the foreign substance found in the tissue are described.
Matching Matches: Part 3
Thomas J. Hopen, ATF Forensic Sciences Laboratory; Chris Taylor, U.S. Army Criminal Investigation Laboratory; Larry Peterson, Georgia Bureau of Investigation; and Walter Rantanen, Integrated Paper Services, Inc.
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, microspectrophotometry, as well as use of Photoshop in the comparison of the match stem color.
Investigation of Post-Flight Solid Rocket Booster Thermal Protection System
Linda Nelson, United Space Alliance, LLC
After every Shuttle mission, the Solid Rocket Booster (SRBs) are recovered and observed for missing material. Most of the SRB is covered with a cork-based thermal protection material (MCC-1). After the most recent shuttle mission, STS-114, the forward section of the booster appeared to have been impacted during flight. The darkened fracture surfaces indicate that this might have occurred early in flight. The scope of the analysis included microscopic observations to assess the degree of heat effects and locate evidence of the impact source as well as chemical analysis of the fracture surfaces and recovered foreign material using Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy/Energy Dispersive Spectroscopy.
The amount of heat effects and presence of soot products on the fracture surface indicated that the material was impacted prior to SRB re-entry into the atmosphere. Fragments of graphite fibers found on these fracture surfaces were traced to slag inside the Solid Rocket Motor (SRM) that forms during flight as the propellant is spent and is ejected throughout the descent of the SRB after separation. The direction of the impact mark matches with the likely trajectory of SRBs tumbling prior to re-entry.
The World’s Worst Microscopy
Brian J. Ford, Gonville and Caius College, Cambridge University
Once again, Brian scours the world of scientific reporting and laboratory practice for examples that can win our nomination for the worst microscopy of the past twelve months. Delegates to I/M 2006 are encouraged to send their own examples in so that they can be added to the list. This fascinating summary has become a landmark presentation at Inter Micro and this year’s entrants will be well up to the standard we expect (or ‘down to,’ depending on how you look at these things).
The Use of Microscopic Trace Evidence to Develop Investigative Leads in Criminal Investigations
Skip Palenik, Microtrace
The majority of trace evidence examinations performed by forensic science laboratories at present are devoted to comparisons between known and questioned evidence. Scientific examinations of microscopic evidence for the purpose of developing investigative leads are rarely performed for a variety of reasons, not the least of which is the current trend of requiring fixed procedures (protocols) before an examination of any type is undertaken. Developing useful information from a few particles of dust does not lend itself to fixed procedures but calls instead for the ability to perform accurate identification and analyses of entirely unknown substances as well as skill in interpretation which can only be cultivated by experience gained over time.
This presentation will briefly describe two historic investigations that inspired the author in his boy scientist days and then describe his recent work on a series of unsolved rapes in Montgomery County (Rockville), Maryland. The identity of the rapist remained unknown for three years in spite of the fact that his DNA was identified in every one of the crimes. Investigative leads developed from items of clothing left at two of the rapes led to the apprehension of the suspect and his subsequent confession. The methods of analysis applied and the conclusions drawn from them will appear surprisingly simple when the results of the analyses and the reasoning applied to them is explained.
Structure-Property Relationships in Nanomagnetic Materials
A.K. Petford-Long, Argonne National Laboratory
There is a wide range of novel magnetic phenomena that are exhibited by nanoscale magnetic materials, including giant magnetoresistance (GMR). The materials from which these structures are fabricated are inhomogeneous at the nanoscale, and the novel magnetic and transport phenomena that these materials exhibit depend critically on their microstructure and composition, with variations on the atomic scale leading to variations in properties. We have applied high resolution electron microscopy (HREM), transmission electron microscopy (TEM) chemical mapping and three-dimensional atom probe (3DAP) analysis to a range of information storage materials including spin-dependent tunnel junctions, multilayers composed of materials suitable for spin-valves and magnetic nanoparticles.
The behavior of these materials relies on the local magnetic domain structure and magnetization reversal mechanism, and one of the techniques enabling micromagnetic studies is Lorentz transmission electron microscopy (LTEM) which allows the magnetic domain structure and magnetization reversal mechanism of a FM material to be investigated dynamically in real-time with a resolution of a few nanometres. We have used LTEM or off-axis electron holography, combined with in-situ magnetizing experiments to analyze magnetization reversal in a range of materials including spin-tunnel junctions and patterned magnetic arrays. Quantitative analysis of the Lorentz TEM data enables access to the phase change experienced by the electrons, and this allows quantitative maps of the in-plane magnetic induction of the sample, in a plane perpendicular to the electron beam, to be obtained.