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The Microscope - Volume 65, First Quarter 2017

IN THIS ISSUE:

On the cover:
Quantitative volume fraction measurements of nodular cast iron (top) and flake graphite cast iron (bottom) surfaces are obtained by superimposing a grid of points onto the images. See Stereology: An Introduction to Some Basic Structural Measurements, page 3. (Photo courtesy of John C. Russ)


Editorial | T-shirts, Atoms, and the Lost Art of Crystal Rolling

Gary J. Laughlin
The Microscope 65 (1), p ii
Excerpt: The study of crystals (orderly, repetitive, three-dimensional atomic structures) through the microscope is essential to the identification of a wide variety of small particles. Essentially, all solid particles may be classified as “made up of atoms” and either crystalline, non-crystalline, or microscopically and optically like a crystal but lacking a crystal lattice. One necessary requirement for a good description, and to show the orthographic projections, is to orient and roll the crystal, which is similar to the function of a universal stage or the spindle stage.


Stereology: An Introduction to Some Basic Structural Measurements

John C. Russ
The Microscope 65 (1), pp 3 – 12
Abstract: Quantitative measurement of structures in both biological and inorganic specimens can be efficiently obtained by superimposing simple grids of lines and points onto images of surfaces or thin sections obtained by light and electron microscopy. In many cases, counting the intersections or “hits” the grid makes with the structures of interest provides efficient determination of volume fraction, areas of surfaces (interfaces, cell membranes, etc.), and lengths of linear structures (fibers, vasculature, etc.). In some cases, the number of objects per unit volume can also be determined. Counting also provides an estimate of the precision of the measurements and facilitates the design of experiments. Examples are shown covering a wide range of disciplines.


The Discrimination of Pencil Marks on Paper in Forensic Investigations

Correction: The print version of this article has the wrong image of the “completed and ready Duro-Tak ball” for Figure 2 on page 14. The original version of the article and a Correction page with the correct Figure 2 image are available as a PDF from the link below. The Microscope regrets the error.

Larry Peterson
The Microscope 65 (1), pp 13 – 20
Abstract: Little information is available on the ability to discriminate pencil marks on writing paper, primarily due to the lack of a method to remove pencil marks from the paper substrate. In this study, pencil marks were removed from the paper backing using Duro-Tak 405A, an acrylic-based adhesive. Removed markings were analyzed using a combination of X-ray fluorescence (XRF), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and chemical extraction. Of the 12 No. 2 pencils studied, all but one pair of samples was discriminated.
Full article and correction (PDF)


Critical Focus | The Latest Tally: 100 Talks … and Counting

Brian J. Ford
The Microscope 65 (1), pp 21 – 31
Excerpt: Columns aren’t easy to write, and this one is unusually challenging. The brief is to look back at 100 presentations given to the same conference [Inter/Micro], yet without it looking like a shopping list. This will be unusual — and it takes me straight back to 1969. If you were around at the time, it was an unforgettable year.


Microcrystal Tests for the Identification of Illicit Drugs: Cocaine

Kelly M. Brinsko, M.S.; Dean Golemis, B.A.; Meggan B. King, B.S.; Gary J. Laughlin, Ph.D.; and Sebastian B. Sparenga, M.S.
The Microscope 65 (1), pp 33 – 44
Excerpt: The Microscope is publishing selected monographs from McCrone Research Institute’s “A Modern Compendium of Microcrystal Tests for Illicit Drugs and Diverted Pharmaceuticals,” which contains 19 different drugs and their microcrystal test reagents. This installment includes four monographs for cocaine with the reagents gold chloride with acetic acid, gold chloride with hydrochloric acid, platinum chloride with acetic acid, and platinum chloride with hydrochloric acid.









Afterimage | Potassium Perchlorate Party

JenaMarie Baldaino
The Microscope 65 (1), p 48
A color-enhanced SEM photomicrograph of potassium perchlorate from firecrackers after recrystallization from a water extract.


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