image description

The Microscope - Volume 69, First Quarter 2022

IN THIS ISSUE

What Happened to 2021?

This issue, Vol. 69, First Quarter 2022, is the current edition of The Microscope; the preceding issue Vol. 68, Third/Fourth Quarters 2020 was published last year. The Microscope has leaped over publication-year 2021 and into 2022 due to the Covid-19 pandemic, which caused disruptions and backlogs in our publishing operations during the last two years. Maintaining an uninterrupted year sequence at this point was making the current research that we publish appear dated. More important is the continuous volume number, which is the principal issue identifier of most research journals. Subscribers, be assured that your subscription-term expiration will be updated and not be affected by the change. We hope you enjoy the variety of topics in this issue of The Microscope and look forward to your continued readership. Questions? Email us at themicroscope@mcri.org.

On the cover:
Photomicrographs of a selection of single fibers targeted for UV-Vis MSP analysis, illustrating the color fading effects observed through microscopical observation.
See The Effect of Ultraviolet Radiation on Dyed Man-Made Textile Fibers Using UV-Vis Microspectrophotometry (MSP), page 3. (Chart courtesy of Patrick Buzzini)



Editorial | The Microscopy of Degradation

Dean Golemis
The Microscope 69:1, p ii, 2022

Excerpt: Forensic casework often involves the examination of dyed man-made fabrics and fibers, which are often degraded by environmental conditions, especially prolonged exposure to ultraviolet (UV) radiation from sunlight and artificial light. But little is known about how the dyed fibers are affected by UV light sources. Enter UV-visible microspectrophotometry (UV-Vis MSP), the preferred microanalytical technique to study small sections of these fibers, preferably without inflicting further damage to them.



The Effect of Ultraviolet Radiation on Dyed Man-Made Textile Fibers Using UV-Vis Microspectrophotometry (MSP): Technical Aspects on Spectral Alterations in Time

Patrick Buzzini, Meggan King Dempsey, Gary J. Laughlin, and Sebastian B. Sparenga
The Microscope 69:1, pp 3 – 24, 2022

Abstract: Little is known about changes in dyed man-made fibers caused by environmental conditions, especially exposure to ultraviolet (UV) radiation over long periods of time. Even less known are the deviations of the spectral curves collected from these samples using UV-visible microspectrophotometry (UV-Vis MSP) from the spectral curves collected from unexposed fiber samples. Spectral alterations, however, may derive from undesired causes inherent to the operation of the instrument or the samples themselves. Hence, the primary goal of this research was to study the effect of UV radiation on various combinations of man-made fiber types, color, and dye types. A UV radiation box was constructed as a controlled (indoor) environment and was compared to a dedicated (outdoor) natural exposure facility in Buckeye, AZ. In both settings, the fiber samples were exposed up to 32 weeks and collected and analyzed at intervals of 8 weeks. The undesired causes of UV exposure of induced photobleaching inherent to the xenon source of the spectrophotometer and the latent polarization of the selected fiber samples as a function of their orientation on the stage of the microscope were also evaluated.

Although issues due to latent polarization from the samples were not identified, induced photobleaching was observed within 8 seconds of exposure to the xenon source in a few instances. In this study, different types of spectral alterations were observed, which occurred both in the visible and the UV spectral regions. These alterations were the same as observed in the indoor setting, the outdoor setting, and the instrument-induced photobleaching study, although their times of occurrence differed.

This study focused on technical aspects related to the proper use of UV-Vis MSP to the analysis of textile fibers exposed to UV radiation. It has led to the formulation of recommended measures that aim at minimizing the risks of spectral alterations resulting from causes other than the environmental UV exposure of interest.



Critical Focus | Our Disappearing Dirt



Brian J. Ford
The Microscope 69:1, p 25 – 36, 2022

Excerpt: Soil is not some plain substance we step on but a habitat for hungry microbe communities working diligently to make it vanish forever — spurred on by harmful human intervention.

We dismiss it as dirt. Well, people call it dirt, but to me it’s a paradise, rich in complex life and harboring all manner of mysterious creatures. Whatever you think about soil, if you want to appreciate it you should best do so soon. Dirt won’t be here long. It’s evaporating before your eyes; give it half a century and most of it will be gone. And why? Because microbes like to consume the organic component of soil. They metabolize it, converting it to carbon dioxide and water vapor, and it simply floats off into the air. It leaves nothing behind.



On Magnification, Calibration, Visibility, and Resolution

John C. Russ
The Microscope 69:1, pp 37 – 41, 2022

Abstract, and a Warning: What follows is basically a commentary, and a somewhat exasperated one at that. The author has been involved with microscopy and related instrumentation in many forms (light, electron, scanned probe, acoustic, neutron, and X-ray in 2-, 3- and 4-D), and with the processing, measurement, and analysis of images for nearly seven decades. He has reviewed hundreds, if not thousands, of papers and proposals. During that time he has often been frustrated by the errors he has encountered, whether due to oversight, misunderstanding, or willful ignorance of the concepts listed in the title. The terms seem to be familiar and well understood, but there remains plenty of room for confusion; so let’s try to be clear about 1) what they mean and 2) how to assure that we are using and measuring them properly.



Microscope Past: 30 Years Ago | The Use of the Common Glue Gun in Light and Scanning Electron Microscopy

Leo Barish
The Microscope 69:1, pp 43 – 47, 2022
Originally published in The Microscope, Volume 39, Third/Fourth Quarters, pp 175 – 185, 1991.

Abstract: Because the common glue gun can simplify the application of melts, it has proven to be most helpful in microscopy. Some procedures employing the glue gun include: the attachment of specimens to studs in SEM, the formation of a permanent mounting medium, the embedment of specimens for cross-sectioning, the replication of surfaces and the ringing of coverslips.



Afterimage | Boundary Migration



Andrew Anthony Havics — pH2, LLC
The Microscope 69:1, p 192, 2022

Crystals of 2,4-dichlorophenol (DCP), used in the production of herbicide 2,4-D (dichlorophenoxyacetic acid), exhibiting grain boundary migration on a hot stage, wherein two crystals (identical phases) have contacted and proceeded to grow into and through each other simultaneously; original field of view is 110 × 155 μm.



Subscribe to The Microscope

Copyright © 2022 Microscope Publications, Division of McCrone Research Institute. All rights reserved.