Technology Bulletin 1002

DN Staff

March 3, 1997

8 Min Read
Technology Bulletin

Laser-based treatment could benefit stroke victims

Researchers at Sandia National Laboratories are helping Wellman Laboratories of Photomedicine, a leading research institution on laser/tissue interaction, to better understand a new laser-based therapy for the victims of subarachnoid hemmorrages (SAH). Current treatments, such as general or local muscle relaxants and balloon angioplasty, have been largely unsuccessful. The new procedure, called "pulsed laser hydraulic vasodilation," offers more hope, says Robert Setchell, a researcher at Sandia's Advanced Systems Technology Department. The procedure requires a very flexible catheter be placed in the artery that extends from the patient's leg up to the brain. The catheter contains and guides an optical fiber and saline solution to the constricted area. A laser is fired through the optical fiber, instantly causing the saline near the end of the fiber to heat to above the boiling point. A vapor bubble forms and grows, which produces a fluid surge or "hydraulic pulse" in the artery. This results in a sudden pressure increase that forces the artery to stretch and remain open. E-mail [email protected].

Light-emitting silicon coupled with conventional circuitry

Engineers at the University of Rochester and the Rochester Institute of Technology have taken an important step toward the long-sought marriage of electronics and optics by integrating a porous silicon light-emitting diode (LED) into conventional microelectronic circuitry. The technology will make possible an all-silicon system that can process light as well as electricity. "This is a necessary rite of passage if porous silicon is to truly become a technology," says Philippe Fauchet, professor of electrical engineering at the University of Rochester. To accomplish this feat, the engineers removed hydrogen atoms from the outer layer of silicon nano-particles less than 100 angstroms wide. They then replaced the hydrogen with a double layer of silicon oxide to create a porous silicon known as silicon-rich silicon oxide. These steps enable the material, which is about three-quarters air and only one-quarter silicon, to withstand temperatures of 900C. FAX (716) 275-2073.

Copper a more perfect electronics material?

Purity is not necessarily an advantage in electronic materials, at least according to Shyam Murarka, director of the new Semiconductor Research Corporation (SRC) at Rensselaer Polytechnic Institute. He leads a research effort that uses "advantageous impurities" in copper to help increase speeds on advanced computer chips. Most interconnects are aluminum, but as circuits grow smaller and faster, that metal is reaching its physical limits. One solution: replacing aluminum connections with copper, says Murarka. Copper has a lower resistance than aluminum, and it lets messages travel more quickly. It is also reliable, easy to deposit, and can be processed by chemical-mechanical planarization, a technique used to create level surfaces in the manufacture of multilevel chips. The main drawback: copper corrodes more easily than aluminum, and diffuses through the dielectric materials into the silicon devices. Murarka hopes to solve this through the addition of small amounts of magnesium, aluminum, or boron. E-mail [email protected].

Miniature camera project focuses on security

Police, security guards, and the public may soon have access to a miniature video camera developed by Oak Ridge National Laboratory (ORNL) researchers and licensed by Turtle Mountain Communications, Maryville, TN. For the project, Instrumentation and Control Div. researchers at the lab reduced the size of the lens on a commercial video camera, then equipped it with a transmitter that sends the picture to a site up to 100 feet away. Another key feature of the camera is its disguised lens. The aperture has been moved from the middle of the lens mechanism to the front, leaving only a pinhole size opening. "This makes the camera unobtrusive," says co-inventor David Sitter. Researchers expect the camera to be little larger than a microcassette case (about 1 x 2 x 1/2 inches). This would make the device small enough to place in police or security badges and other tiny objects. FAX Ron Walli at (423) 574-0595.

Glass formulation to set 'new industry standard'

Owens Corning has launched AdvantexTM, a glass-fiber reinforcement that the company predicts will become a new industry standard because of its enhanced heat and corrosion resistance. The glass fiber combines the electrical and mechanical properties of the current industry standard--E-glass--with higher heat resistance and the acid-corrosion properties of E-CR glass, according to Rhonda Brooks, vice president, marketing, Composites. "The introduction of Advantex glass fiber marks another industry milestone in Owens Corning's tradition of innovation," Brooks adds. "An important advantage of Advantex is the common technology platform it provides, which enables customers to confidently specify the same product anywhere in the world." The glass-fiber reinforcements will be available in both continuous and chopped strands. The new formula, Brooks notes, also minimizes air pollutants during the manufacturing process without relying solely on costly control devices. FAX William K. Hamilton at (800) 758-5804, ext. 677350.

Coating has the touch of leather or suede

A new coating promises to give virtually any product the look and feel of expensive leather or suede. Developed by the Alsa Corp., Vernon, CA, the Sof-TouchTM polyurethane-based coating can be applied on wood, metal, glass, plastic, paper, PVC, or many other substrates to produce a variety of velvety, leather-like surfaces. "It is incredibly soft and feels almost fragile to the touch," says Ike Banoun, Alsa president, "yet its surface is far more durable than leather and can't be scratched." A solvent-based, crosslinked, two-part system, the product coating and catalyst remain separate until they are ready to apply. Once mixed, the material has a pot life of about three hours. It may be mixed and applied with conventional spray equipment and requires no special training to use. FAX Banoun at (213) 581-6523.

Digital analysis of speech could lead to sobriety test

Slurred speech often portends that someone's been drinking. Now, a Georgia Tech researcher, in collaboration with colleagues from Indiana University, has under development a way to digitally quantify this telltale sign. It could, says Georgia Tech's Kathleen Cummings, an instructor in the School of Electrical and Computer Engineering, lead to a simple, non-invasive way to test a person's sobriety. "This is basically an effect of fine motor control," Cummings explains. "We're looking specifically at what happens during speech production at your vocal cords, how steadily you can produce the excitation going through those cords." Cummings believes that translating her research into a practical public-safety device could be relatively easy. Law enforcement officials could record someone's speech at an accident or traffic stop, then analyze it later by computer against a sample taken at a different time. E-mail [email protected].

Clock could reset itself after power outage

You know the drill. A thunderstorm knocks out your power, and afterward you trek from room to room resetting the time on clocks, appliances, and VCRs. Someday these clocks may reset themselves to within a few hundredths of a second with time and frequency signals broadcast from the National Institute of Standards and Technology (NIST). The Institute has boosted the power of time and frequency signals broadcast from its radio station, WWVB, in Ft. Collins, CO., increasing the power of the signal four-fold. This, in turn, provides more reliable coverage to the far corners of the continental U.S., Mexico, and southern Canada. The station improvement will provide a signal strong enough to be picked up with much smaller antennas than the bulky ones previously required for distant locations. In fact, the signal is so strong that manufacturers now should be able to build automatic, WWVB-controlled clocks into all kinds of appliances, even wristwatches. Telephone Wayne Hanson at (303) 497-5233.

Real-time furnace contouring sensor tested

Initial tests of an instrument for rapid, continuous measurement of the interior surface of steelmaking vessels have begun at Bethlehem's Sparrows Point facility. Using a stand-alone Scannerless Range Imager (RI), researchers from Sandia National Laboratories successfully demonstrated the feasibility of imaging the interior of a hot furnace vessel in seconds, under normal operating conditions. Currently, furnace interiors are checked daily for refractory wear, using a time-consuming, portable, laser-scanning technique with the vessel in the "turned down" position. SRI would enable furnace contouring to take place in real-time, eliminating costly furnace downtime, while maximizing the vessel lining life. The SRI sensor is the final component to be incorporated into a lance-based sensor being developed by Sandia, Insitec Inc., Berry Metal Co., and Bethlehem Steel under a program sponsored by the American Iron and Steel Institute. FAX Mark Stephenson at (202) 463-6573.

Open access system wholesales electric-power services

Using the new Open Access Same Time Information System (OASIS), "cybersales" of wholesale transmission services can be conducted on the electric grid. The Electric Power Research Institute (EPRI) and the North American Electric Reliability Council (NERC) jointly spearheaded the OASIS design and testing in response to federally mandated, open-access electric power transmission. "Authorized users anywhere in the world have access to transmission services being offered by providers," notes Peter Hirsch, EPRI manager of power systems engineering. This is possible through the use of tools based on standard Internet applications, such as World Wide Web browsers, HyperText Markup Language (HTML), and Hypertext Transport Protocol (HTTP). The OASIS network is structured around 22 computer nodes located across the U.S., each of which corresponds to a communication and information processing system. The nodes act like "hubs" for wholesale transmission providers and their customers. E-mail [email protected].

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