Marked bullet casing won't solve crime; MRF is better suited to lower volumes; Field effects credited for eye repair...

Marked bullet casing won't solve crime

Your December 2002 cover story "Laser etching may help investigators ID bullets," (December 2002, p. 13), contained several glaring problems with the title, content, and logic contained in this story. The most obvious erroneous statement is that bullets will be identified and traceable to a specific firearm. It is the case that will be marked and, thus, identifiable, not the bullet.

Jason R. Guth
Materials Engineer
Hawthorne & York Intl.
Chandler, AZ

Note that the technology described would not identify the bullet, but rather the cartridge primer or the cartridge case. The bullet is the portion that flies out the front of the firearm, the brass cartridge case remains in the firearm or is ejected, depending on the firearm design, and may or may not be found at the site where the firearm was discharged.

While the technology may indeed be useful in forensic investigations, it would not provide identification of the bullet.

Alan Boyer
Keene, NH

MRF is better suited to lower volumes

Thank you for mentioning us in the November issue ("Semi-flexible tools remove ripples," November 2002, p. 17). Let me clarify a fairly common misconception of magnetorheological finishing (MRF). Magnetorheological finishing is actually better suited for "low- and medium-volume" production than for "high-volume production." In addition, I would also suggest that while the MRF machine cost is higher than more conventional polishers, MRF is much more efficient (cycle-time, yield, flexibility, automation) than conventional polishing, resulting in a very attractive cost of ownership.

Don Golini
QED Technologies
Rochester, NY

Field effects credited for eye repair

I read with great interest your article "LEDs may heal laser-damaged eyes," (October 2002, p. 20). But I would debate with you about some of your conclusions. We have carried out complex investigations to clarify the mechanisms of laser and light treatment. At this time, we are sure that the main (trigger) mechanism is based on field effects, which lead to restructure of biological liquids in an organism. We detected these effects in biological models, blood samples, and directly in irradiated organisms. We also have arrived at the conclusion that the laser source does not have any advantage compared with LEDs, but will if some special conditions are met.

Valeri Zakharov
Samara State Aerospace University

We welcome your comments. Please send letters to Carol Settino, managing editor, at carols@pennwell.com. Letters may be edited for length.

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