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. LaughlinThe Microscope 65:1, p. ii, 2017https://doi.org/10.59082/GZEF5969
Excerpt: T-shirts with rock band logos and messages were all the rage when I was growing up in Chicago during the 1960s and 1970s. For a few dollars, I could go to The Funny Farm, a local tricks and gags shop on Devon Avenue, and purchase a new, white shirt and choose from dozens of iron-on transfers that the store owner would apply for you “while-u-wait.”
Stereology: An Introduction to Some Basic Structural Measurements
John C. Russ
The Microscope 65:1, pp. 3–12, 2017https://doi.org/10.59082/PHDU7030
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.
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
Larry PetersonThe Microscope 65:1, pp. 13–20, 2017
https://doi.org/10.59082/UGAA9931
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.
Critical Focus | The Latest Tally: 100 Talks … and Counting
Brian J. FordThe Microscope 65:1, pp. 21–31, 2017
https://doi.org/10.59082/KFII9654
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, 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, Dean Golemis, Meggan B. King, Gary J. Laughlin, and Sebastian B. Sparenga
The Microscope 65:1, pp. 33–44, 2017https://doi.org/10.59082/JYFC8683
Abstract: 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 (see pages 34–44).
Afterimage | Potassium Perchlorate Party
JenaMarie Baldaino
The Microscope 65:1, p. 48, 2017
A color-enhanced SEM photomicrograph of potassium perchlorate from firecrackers after recrystallization from a water extract.
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