Technology bulletin 1049

DN Staff

September 8, 1997

9 Min Read
Technology bulletin

Air-toair missile to acquire new tactical skills

McDonnell Douglas has received a contract to develop technology for a "revolutionary" new air-to-air missile. During the five-year, $22 million program, the company hopes to design and demonstrate an advanced flight control system that will allow a single missile to perform close-in and beyond-visual-range air-to-air missions. "The dual range capability of the missile results from a hybrid combination of flight control and propulsion technologies for both short and longer range missiles," notes Larry Perlmutter, program manager. The new flight control system combines small, side-thrusting reaction jets integrated into the aft section of the main rocket motor with reduced-span tailfins. The jets, which bleed propulsive gas from the rocket motor, are used when high levels of agility are required to engage a threat. The Air Force envisions using the dual-range missile concept on an advanced fighter aircraft that would also include a helmet-mounted sighting system. FAX (314) 234-4878.

Better parachutes through computer simulation

Parachutes have long played an important role in the deployment of soldiers, ammunition, equipment, and supplies. Airdrop technology will take on an even greater role in the future, as humanitarian operations increase in frequency and demand for the rapid deployment of food, medicine, and relief shelters rises. Helping to advance airdrop capabilities is the Computational Analysis Team (CAT) at the Natick (MA) Research, Development and Engineering Center. The team has under development analytical models that predict the physics of parachutes by coupling equations that govern the air to equations that govern the motion of the parachute. Soon, designers can use computer software based on these models to create new parachute systems, rather than relying on full-scale testing. To date, the team has designed an axisymmetric model that features coupled structural dynamics code and computation computational fluid dynamic codes. Next: applying the approach in 3-D. FAX (508) 233-5390.

Magnetic tweezers move DNA molecules

Magnetic tweezers developed at Johns Hopkins University could help a physician move a microscopic sac filled with cancer-destroying medicine through a patient's vein, then dump the sac directly into diseased cells. The magnet consists of three sets of coiled copper wires, each connected to a power source. The coils are positioned to produce electromagnetic fields backward and forward, side to side, and up and down. With a joystick, the tweezers' inventor, Denis Wirtz, an assistant professor of chemical engineering, can shift the amount of electricity flowing to each set of coils to move a magnetic object. The tweezers are currently being used to manipulate DNA molecules coated with iron oxide beads no larger than one-hundredth of a micron in diameter. This allows Wirtz to measure how a DNA molecule moves and changes shapes. Wirtz feels that the sac study will provide data for many other potential uses for his technology. E-mail [email protected] .

Technology 'prints' tailored drugs

Researchers at the Massachusetts Institute of Technology have devised a technique for "printing" drugs into pills using a 3-D printing device similar to a computer inkjet printer. The process involves dropping a precise drug dose onto a thin layer of fine powder in a process repeated between 30 and 50 times. The developers, Michael J. Cima and Emanuel M. Sachs, believe the technique can deliver ultra-precise doses. It can also put a cocktail of drugs into a single tablet and make slow-release tablets that deliver very precise doses at different times. Currently, the process is limited to drugs of low dosages, such as a few milligrams, because the drug is deposited as a solution. Other methods, including mixing the solid form of the drug with the matrix powder and enhancing the drug's solubility, are being investigated. The process is now under review by the FDA. E-mail [email protected] .

Teraflops computer up and running for first time

The full complement of 84 cabinets that compose the teraflops high-performance ultracomputer, said to be the fastest in the world, have begun operation at Sandia National Laboratories. The Intel massively parallel computer consists of 76 computer cabinets with 9,072 Pentium Pro processors. It has nearly six hundred billion bytes of memory. The remaining eight cabinets, called disconnect cabinets, separate the machine so that classified and unclassified calculations can be run at the same time. The entire computer consists of four rows with 21 cabinets in each row. It covers about 1,600 sq ft. The system can perform up to 1.8 teraflops or floating point operations per second. It would take someone operating a hand-held calculator about 57,000 years to calculate a problem the teraflops computer could do in one second. FAX (505) 844-6367.

Energy-storage system bridges power disturbances

The plant manager at the Brockway Standard Lithograph plant (Homerville, GA) works a lot more relaxed during thunderstorms these days. No longer will slight voltage sags or swells wreak havoc with the sensitive electronics that control his metal printing and curing process. In a pilot project funded by Oglethorpe Power Corp. and the Electric Power Research Institute, the first commercial installation of a PQ2000 energy storage system developed by AC Battery Corp. operates at the Brockway facility. The system continually monitors the voltage supplied to the plant and compensates with a brief energy supply of its own whenever a disturbance is detected. If needed, the system can deliver up to 2 megawatts of energy in about 1/4 cycle (1/240th of a second) to maintain power to critical equipment. Self-contained, the system fits into an outdoor area of about 30 x 40 ft. It consists of: an Electronic Selector Device, a matching transformer, and the PQ2000. At its heart are 48 Delco 1150 maintenance-free batteries, an inverter and bridge, a charger, and a hydrogen exhaust system. A computer monitors the system and records the number of times it runs. E-mail [email protected].

Mini pump could simplify diabetics' lives

Biomedical engineers at Case Western Reserve University have built a prototype drug pump the size of a contact lens. The miniature implant could monitor its own flow rate to ensure a steady stream of medicine, such as insulin for diabetics. The closed-system micropump employs a flow sensor to measure and adjust the pumping rate for more accurate pumping. The prototype, invented by Michael Huff, an assistant professor of electrical engineering and applied sciences, and a diabetic, reports that his prototype consists of a rectangular silicon chamber with one of the outer walls made of two thin layers of a titanium-nickel alloy sandwiched around a layer of silicon. The alloy forcefully changes shape when heated to around 60C. To operate the pump, a staggered pulse of electrical current passes directly through the alloy, setting up a cycle of heating and cooling that causes it to flex. This forces the chamber to expand and contract. The expansion pulls fluid into the chamber through an intake valve, and the contraction expels the fluid through an exhaust valve. FAX (216) 368-2668.

Novel metals furnace flies on the Space Shuttle

Pennsylvania State University researchers launched the Large Isothermal Furnace (LIF) on the most recent Space Shuttle voyage to conduct a series of experiments on the formation of metal alloys. The furnace, developed by the National Space Development Agency of Japan, heated powdered-metal mixtures of tungsten, nickel, iron, and copper at very high temperatures until some of the metal particles melted and caused the whole mass to stick together or sinter. The same technique is used on Earth to make teeth fillings, golf clubs, armor-piercing bullets, and radioactive heat shielding. "Understanding the rules" that metal mixtures follow when sintered may eventually enable the researchers to develop techniques that permit the production of tungsten alloy containing more copper, for example. An earlier series of experiments were aboard another shuttle flight in April, but the mission had to be cut short because of the shuttle's electrical problems. However, three of the five experiments were processed. "We're still completing the analysis, but the data appear to show us that the higher number of grains that are in direct contact with one another, the fewer you need to have in the mix," reports Randall German, the study's chief investigator. E-mail [email protected] .

Artificial intelligence helps find cancerous breast tissue

Researchers at Washington University in St. Louis have under development a novel way to pre-screen mammograms. It's based on the use of an intelligent computer system trained to recognize abnormalities in breast tissue. The researchers, Barry L. Kalman and Stan C. Kwasny, research associates in the computer science department, used the system to analyze 55 two-view, digitized mammograms of biopsied patients. The system correctly identified 79% of images where cancer was present. Once perfected, the method should lessen the workload of radiologists who examine an increasing number of women undergoing screening for early detection of cancer. The technique also could reduce costs involved with unnecessary trips to a specialist to interpret X-ray images. The goal: 95% accuracy in discriminating normal mammograms from those that indicate possible cancers. E-mail [email protected] .

Generator harnesses the wind more efficiently

A prototype generator built by a researcher at the Rensselaer Institute of Technology could make wind power more practical for farms, isolated homes, and remote settlements in Third World countries. David A. Torrey, an associate professor of electric power engineering, reports that his variable-reluctance generator has the potential to act as a robust and highly efficient electrical conversion system for use with variable-speed, direct-drive wind turbines. The generator operates at no more than 120 rpm--about 15 times slower than an off-the-shelf generator. This eliminates the need for a gear box, which reduces construction costs and provides a sturdy, low-maintenance system. Following the successful demonstration, Torrey plans to redesign the generator based on what he has learned, build another, and incorporate it in a turbine for field testing. E-mail [email protected].

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