NEWS
1992 Waters Symposium Proposals Proposals are solicited for the 1992 James L. Waters Annual Symposium recognizing collaboration in the in vention, development, and implementation of estab lished analytical instrumentation. These symposia stim ulate awareness of how new instruments—and through them—new fields are created, how inventors perceive the need for new instrumentation, and how difficulties are overcome in creating a commercial instrument. Pre vious symposia covered gas chromatography (1990) and atomic absorption spectroscopy (1991). Proposals, including a list of individuals available to speak on the invention, production, and use of the sub ject instrumentation, should be sent to Richard Obrycki, PPG Industries, Inc., 440 College Park Dr., Monroeville, PA 15146. Deadline is April 30.
Image Analysis for PCs?
Clustering is not new, but earlier programs employing this technique used too few clusters and overlooked im portant details. The Los Alamos technique increases the number of clusters to 256, which researchers say provides an accu rate representation of the data. According to White, im age processing that takes about three weeks by the old methods would only require a day with their clustering program. "Our system is so good that even experts in this field can rarely tell the difference between the origi nal data and our clustered data."
Chip Off the Old Laser Scientists at IBM's Zurich Research Laboratory report that they have, for the first time, been able to mass pro duce and test as many as 20,000 semiconductor lasers crammed onto a 5-cm diameter wafer. The development opens the way for less expensive and higher quality semiconductor laser chips. In addition, the announce ment promises advances in the manufacture of optoelec tronic chips that use both light and electric current to carry information. The semiconductor lasers (see photo) are fabricated by epitaxily depositing doped AlGaAs crystals on a substrate, where they emit light at 830-850 nm. Mirrors for the la sers are formed from the sides of δ-μΜ-deep trenches next to the laser. The trenches are etched into the semiconductor crystal by photolithography and then coated with a semireflective material. Photodiodes and other com ponents are fabricated into the wafer for testing of the lasers. Following perfor mance checks, the wafer is sliced into individual lasers.
Researchers at Los Alamos National Laboratory have developed a new computer algorithm that they claim greatly speeds the analysis of images and reduces them to a form that can easily be manipulated and analyzed by a small computer. The new technique is being applied to the analysis of satellite images. According to James White of Los Alamos's Computer Research and Applications Group, "[The system] pre sents satellite data in a way that allows it to be manipu lated and understood even by someone who is not an expert in remote sensing." Images from satellites, such as Landsat, can be used to identify such features as forests, grasslands, urban areas, and even likely sites for oil or certain minerals. However, traditional methods of image, analysis require enormous numbers of calcu lations to pull out the rele vant information. The new algorithm is based on a process called cluster ing, in which the computer defines groups with certain characteristics and assigns each pixel to the cluster it most resembles. Thus cluster ing collapses the original im age into a representation de fined by a smaller set of 5000 lasers on a 5-cm wafer. Enlarged photos show an array numbers that require fewer ofsix lasers with photodiodes (left) and a single laser and calculations for analysis. photodiode (right). (Courtesy IBM.)
For Your Information Mass spectrometrist Fred Saalfeld was named Execu tive of the Year by the Fed eral Executive Institute Alum ni Association. Saalfeld directs the Office of Naval Research, which manages about 4500 civilian and military person nel and has a budget of $1.2 billion. The career and life of wellknown analytical chemist Jeanette Grasselli were fea tured in the January 6 edition of The Plain Dealer Mag azine (Cleveland, OH).
ANALYTICAL CHEMISTRY, VOL. 63, NO. 7, APRIL 1, 1991 · 381 A
