Technology bulletin

Electronic signals ride the plasma wave

When a musician blows into a flute and pushes particles of air into a resonance cavity, audience members don't wait for the moving air particles to reach their ears. Instead, a pattern of sound waves quickly carries the music to the listeners. A similar use of plasma waves to carry information could create a whole new generation of devices or "electronic flutes" that are much faster than conventional computer chips. At least that's the belief of Michael Shur, the Roberts Professor of Solid State Electronics at Rensselaer Polytechnic Institute. At present, messages on computer chips are carried by electrons moving in a semiconductor. But if industry is to reach gigascale integrations (1 billion transistors crowded onto a single chip that operates at 1 billion cycles per second) in the next 10 years, these electron messengers need to travel much more quickly. Shur says that plasma waves could carry the data 10 times faster. He and a colleague have successfully built a primitive version of a detector that makes use of the waves. As Shur sees it, the first use of plasma-wave devices may be as extremely sensitive detectors for hard-to-find substances, such as environmental pollutants or minute quantities of explosives. E-mail

One-step system cuts foam part-making steps

Millennium Petrochemicals Inc. has developed a polyethylene rotational-molding system the company says significantly reduces manufacturing steps for making foam parts. The new system eliminates the need and added costs for drop boxes in molds or a secondary foam application step. The technique can produce structures with a solid outer skin and a foam core or inner layer in one continuous molding cycle. In operation, the system blends three polyethylene resins: a compounded pellet for the foam layer and, for the outer skin, a blend of two polyethylene powders. Use of two powder resins for the skin ensures very smooth, pin-hole-free outer surfaces, according to the company. For single-wall foamed parts that require a smoother inner foam surface, a different foaming pellet is recommended. The three ingredients are blended directly in the mold. A dry colorant can be added to color the outer layer. Parts can have an outer skin thickness of 0.08 to 0.25 inch, and a foam layer or core of 0.25 to 6 inches with a density of 8 lb/ft 3. FAX Henry D. Gudrian at (513) 530-6119.

Virtual endoscopy helps determine treatment feasibility

Scientists at Siemens Corporate Research have under development a virtual endoscopy system that could play a big role in helping physicians determine the feasibility of actual endoscopic procedures. In addition, the company says, the system could be used in diagnostic evaluation and physician training. For example, in one "virtual" application--bronchoscopy--a computer model of the trachea, bronchi, and lungs is created using actual computed tomographic (CT) images from a patient. Employing computer graphics, such as CAD/CAM, the CT images are used to re-create 3-D organ models in a computerized format. Similarly, using the dimensions of a real endoscope, a computer model of the camera is created with CAD/CAM, and a computer

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