DLR's control center in Oberpfaffenhofen, near Munich. A shuttle flight next month is scheduled to carry Atlas-2, an atmospheric laboratory for applications and science. An April flight will bear Spacehab-1, a commercially owned pressurized module for conducting experiments, and will retrieve a platform, the European Retrievable Carrier, launched into orbit last August with 15 microgravity experiments. Other shuttle launches are envisaged for July, August, November, and December. The July flight will deploy into space and later retrieve ORFEUS, a German-developed "orbiting and retrievable far and extreme ultraviolet spectrometer/' which will explore the distribution and character of radiationabsorbing material in the solar system. This flight also will deploy an advanced communications technology satellite. The August flight will carry a space life sciences laboratory. A Russian cosmonaut will join the crew for the November launch, which will carry Spacehab-2. And the December flight will rendezvous with the Hubble Space Telescope for repairs and servicing.
There's More Than Pots & Pans in Our Hands
Richard Seltzer
Liquid lead fills carbon nanotubes Nanometer-scale carbon tubules, or nanotubes, readily fill with molten lead by capillary suction, according to researchers at NEC Corp., Tsukuba, Japan. The nanotubes thus act as molds for the fabrication of wires, some of which are less than 2 nm in diameter. Carbon nanotubes consist of concentric graphitic carbon tubes capped by fullerenelike hemispheres that curve through incorporation of five-membered rings. Nanotubes were discovered by NEC's Sumio Iijima in 1991, and a method for bulk synthesis of nanotubes was developed in 1992 by NEC's Thomas W. Ebbesen and P. M. Ajayan. Now, Iijima and Ajayan report that annealing the nanotubes in the presence of liquid lead causes the capped tube ends to open and the tubes to fill with molten material [Nature, 361,333 (1993)]. The NEC scientists first produced nanotubes by the method developed by Ebbesen and Ajayan, dispersed them in ethanol, and deposited the tubes on a perforated carbon grid. They
erving today's contract manufacturing marketplace requires more than an array of reactors — some@ I times known as pots & pans. It requires process expertise and a track record of quality performance in a wide range of chemicals and custom needs —from core to unique technologies. If you require a contract manufacturing partner to help maximize profits and minimize manufacturing hassles, call Cambrex. Let us rattle our pots & pans for you! Call Susan Kolstad at 717-420-3930 for our brochure.
Cambrex Corporation subsidiaries: CasChem, Inc • Heico Chemicals, Inc · The Humphrey Chemical Co., Inc · Nepera, Inc · Salsbury Chemicals, Inc •Zeeland Chemicals, Inc.
Cambrex Corporation CAMBREX
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SCIENCE/TECHNOLOGY
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Wako Chemicals USA, Inc.
Wako
1600 Bellwood Road, Richmond, VA 23237, U.S.A. Telephone: (804) 271-7677 FAX: (804)271-7791 CIRCLE 2 4 ON READER SERVICE CARD
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deposited lead particles with diameters ranging from 1 to 15 nm onto the nanotubes by electron beam evaporation of pure lead under a vacuum. The grid containing the sample was then annealed in an oven for 30 min utes at 400 °C, a temperature that is above the melting point of lead. Exam ination of the annealed sample by trans mission electron microscopy (TEM) showed that the interiors of some of the nanotubes had filled with a solid material. Dispersive x-ray analysis sug gests that the material in the tubes is lead. TEM images of the filled tubes show damage to the nanotube tips but not to other regions of the tubes. The NEC re sults suggest that lead and oxygen at tack the relatively more reactive fivemembered carbon rings at the nano tube tips, opening the tubes and allowing the liquid lead to fill them. The lead extends into the nanotubes up to many tens of nanometers, Iijima and Ajayan report. The NEC scientists suggest that the "modification of carbon nanotubes into composite nanofibers by filling them . . . opens up several possibilities for potential uses/ 7 They believe that sepa rating filled from empty nanotubes should be straightforward, and that the mechanical properties of the modified fibers are likely to be quite different from those of the original material. En capsulation could have intriguing ef fects on the properties of the interior phase, they suggest. Rudy Baum
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Gordon Conference director to retire
FDH
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Alexander M. Cruickshank, 73, orga nizer of the Gordon Research Confer ences for the past 45 years, has an nounced that he will retire as director within the next two years. The board of trustees will retain an executive search firm to hire his replacement. The conferences were founded by chemistry professor Neil E. Gordon of Johns Hopkins University in 1931. First called the Gibson Island Research Con ferences and then the Chemical Research Conferences, they grew from one event in 1931 to 130 conferences this year. Gordon withdrew in 1944 owing to ill health. The gatherings were named the
