Thermal Spore Exposure Vessels

Thermal masses are minimized to enable rapid heating and cooling. Thermal spore exposure vessels (TSEVs) are laboratory containers designed for use in measuring rates of death or survival of microbial spores at elevated temperatures. A major consideration in the design of a TSEV is minimizing thermal mass in order to minimize heating and cooling times. This is necessary in order to minimize the number of microbes killed before and after exposure at the test temperature, so that the results of the test accurately reflect the effect of the test temperature.

Posted in: Medical, Briefs

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Enumerating Spore-Forming Bacteria Airborne With Particles

Complementary data are obtained by use of two instruments and correlated. A laboratory method has been conceived to enable the enumeration of: Cultivable bacteria and bacterial spores that are, variously, airborne by themselves or carried by, parts of, or otherwise associated with, other airborne particles; and Spore-forming bacteria among all of the aforementioned cultivable microbes.

Posted in: Medical, Briefs

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10G and “Killer Apps” Excite Telecom Market in ‘07

In the optical communications industry, it’s important to look back before you look forward. History has a way of putting the future into perspective.

Posted in: Features, ptb catchall, Photonics, Articles

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Laser Diode Market Stays Hot in 2007

The high-power laser diode market has grown rapidly in the last twelve months, a trend that is set to continue throughout 2006 and beyond. The global market for laser systems is forecast to grow by 8% in 2006 to US $5.9 billion, with diode lasers alone growing by 8%.

Posted in: Features, ptb catchall, Photonics, Articles

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Optical Software in ‘07: Isn’t that Easy?

Optical software programs provide optical designers with the means to predict and analyze performance characteristics of optical systems without experimental prototyping. Looking ahead into 2007, optical software will continue to enhance optical design capabilities in several ways. Optical software developers are concentrating their efforts on improving communication channels between engineers in disparate fields who are asked to collaborate. In a word, the direction is “inter-operability.”

Posted in: Features, ptb catchall, Photonics, Articles

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Holographic Plossl Retroreflectors

Lightweight, inexpensive holographic optical elements would be used in place of lenses. Goddard Space Flight Center, Greenbelt, Maryland Holographic retroreflectors that function equivalently to Plossl eyepieces have been developed and used in free-space optical communication systems that utilize laser beams. Plossl eyepieces are well known among telescope designers. They have been adopted for use as retroreflectors and as focusing elements (for reception) and collimating elements (for transmission) in optical communication systems. A retroreflector that incorporates a Plossl eyepiece is termed a cat’s eye retroreflector (see figure).

Posted in: Tech Briefs, ptb catchall, Photonics, Briefs

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High-Speed Laser Scanner Maps a Surface in Three Dimensions

Surface flaws can be scanned automatically and displayed in real time. Ames Research Center, Moffett Field, California A scanning optoelectronic instrument generates the digital equivalent of a three-dimensional (X,Y,Z) map of a surface that spans an area with resolution on the order of 0.005 in. (≈0.125mm). Originally intended for characterizing surface flaws (e.g., pits) on space-shuttle thermal-insulation tiles, the instrument could just as well be used for similar purposes in other settings in which there are requirements to inspect the surfaces of many objects. While many commercial instruments can perform this surface-inspection function, the present instrument offers a unique combination of capabilities not available in commercial instruments.

Posted in: Tech Briefs, ptb catchall, Photonics, Briefs

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