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Mechanical Engineering. 2003;125(09):46-49. doi:10.1115/1.2003-SEP-1.
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This article focuses on innovations done by engineers for spying. If there has been espionage, engineers have been a part of it. In World War II, infiltrators and downed pilots had to be able to find their way behind enemy lines. Compasses were hidden in cufflinks, pencil clips, and buttons. Maps were printed on rice paper so they wouldn't rustle when opened. British pilots wore special flying boots with cutaway tops that, when removed, left normal-looking shoes. Bugging is another method of the spy. The purpose of a bug is to detect sound vibrations in air or in other materials, such as wood, plaster, or metal. A good bug must reject unwanted noise, be easily concealed, and be energy efficient. The United States had an entire listening kit in the 1950s and 1960s with an assortment of accessories like a tie clip and wristwatch microphones.

Topics: Water
Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2003;125(09):50-52. doi:10.1115/1.2003-SEP-2.
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This article illustrates research and development work in nanotechnology for manufacturing computers at the molecular level. Computers have gone from large and mechanical, like Babbage's Difference Engine, to molecular. Researchers have shown that carbon nanotubes can be strung across electrodes to make minute transistors. Beyond sheer density of data, the nanotube chips have another, perhaps even more important, potential advantage over their electronic rivals: the memory does not disappear when the power goes off. The tubes may be drawn to the electrode by an electrical attraction, but they are held there by van der Waals attraction, a sort of molecular-level suction. In that way, an electromechanical memory chip will have more in common with a computer hard drive or floppy disk than with random access memory. Physicist Paul McEuen and his colleagues at Cornell have fabricated a transistor that passes signals through a single atom.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2003;125(09):54-56. doi:10.1115/1.2003-SEP-3.
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Models need to be meshed and made acceptable for analysis before finite element analysis (FEA) can be run. Software providers that make pre-processing applications must keep up with changes in FEA technology to remain competitive. The mesh contains the data on material and structural properties that define how the part will react to certain load conditions. Today's closely integrated computer-aided design (CAD), pre-processing, and FEA applications allow CAD and entry-level FEA technologies to work together within a common user interface and give design engineers a quick, effortless way to see if their designs will meet specifications. Simplifying the FEA programs so a design engineer can use them limits the intricacy of the mesh as well as the depth of analysis. HyperMesh prepares CAD geometries for analysis. The meshed geometries are then exported to Procter & Gamble's customized package analysis system called Virtual Package Simulation. Today, engineers use mesh technologies and attendant FEA programs for an array of analyses. Some are related to manufacturing, but as often as not they've found their way into other industries.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2003;125(09):58-60. doi:10.1115/1.2003-SEP-4.
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MJT Lewis has published a work that is a combination of classical scholarship and pragmatic experimentation, Surveying Instruments of Greece and Rome. Among other things, he has undertaken a comprehensive study of the limits of accuracy that are attainable using modern reconstructions of ancient instruments. Graceful Roman arches, built about 2,000 years ago, held up a carefully crafted water course more than 50 km long, from a rural spring to the city of Nimes. The chorobates was a tool used to get a horizontal reference by sighting along the top. A modern writer, who tried it, doubts its usefulness. The Roman practice of reducing a problem of irregular shapes to a series of manageable-sized orthogonal blocks may have been primitive; however, it got remarkable results. The recent interest in applying modern analytic and experimental techniques to the study of ancient engineering has inspired a good deal of research. Hubert Chanson, a reader in the Department of Civil Engineering at the University of Queensland in Australia, has published several papers on the subject and has mounted an introductory website, ‘Some Hydraulics of Roman Aqueducts’. The site gives numerous references to other literature, including experimental work by himself and V Valenti in 1995.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2003;125(09):62-64. doi:10.1115/1.2003-SEP-5.
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The design analysis techniques, used to determine vulnerability to attack or lethality of an explosive detonation, have been tested against a large database of experimental and test results. Building explosive testing chambers presents a whole new set of challenges, since the purpose of such tests is not the survival or destruction of the vessel, but gaining a better understanding of the explosion's dynamics. Los Alamos and Lawrence Livermore National Laboratory have chosen to combine aboveground testing using mock materials, advanced X-ray and proton radiography, and advanced computing capabilities for complex simulations. These vessel systems, when used with diagnostics such as flash or proton radiography, provide important data that help our weapon's designers validate design codes and support the certification of the weapon systems. The Atomic Weapons Establishment in the United Kingdom has similar activity under way. Testing has shown that within a millisecond, the stresses within the pressure vessel shift from a sharp, uniform impulse to a 1 kHz vibration. The amount of stress, or excitation, that the impulse places on the structure can be figured as the integral of the load over time of duration.

Commentary by Dr. Valentin Fuster

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