Plastic bottles recycled into sails for tall ship Using new and conventional plastics recycling technology, Du Pont has converted plastic soda bottles (right) and plastic car fenders into 13,000 sq ft of sail for the tall ship HMS Rose (left). The largest operational wood en tall ship in the world, the private ly owned HMS Rose is a replica of a British 24-gun frigate of the same name that operated off the U.S/s East Coast during the Revolutionary War. The ship is visiting U.S. ports this summer with a Du Pont plastics recy
to two per year, with no cap on the number of inspections per country. In spections at facilities producing dual-use chemicals would be restricted to two a year, with a country cap of 20 per year. No caps would be placed on the num ber of so-called challenge inspections, a point the U.S. finds problematic. A coun try could delay access to a challenged site for up to five days, but then must al low an inspection team access. "Access is the only thing guaranteed, anything else beyond that is negotiable between the inspection team and the challenged facility// explains a U.S. official. The challenge inspection regime in the draft text is similar to the most recent proposal the U.S. offered, which was crafted to alleviate concerns about pro tection of proprietary information, Fourth Amendment rights, and national security secrets. Challenge inspections are not limited to chemical facilities. Challenge inspections, which would
cling exhibit aboard. Polyester fiber to weave the sail cloth came from more than 126,000 plastic bottles that Du Pont processed through conven tional sort, clean, and grind technolo gy. Additional resins for the sail cloth came from recycled prototype Bexloy Κ polyester composite auto mobile fenders, broken down using a new proprietary depolymerization process. Du Pont will supply Bexloy Κ for a new line of Chrysler automo biles to debut in 1993. The company
last no longer than 84 hours, would be conducted according to the concept of managed access. This means that the inspected facility would be obligated to verify to the inspection team's satisfac tion that no illegal activities are taking place. But in doing so, the inspected site could safeguard whatever it be lieves to be irrelevant to the inspection. It could do this by shrouding equip ment, turning off computers, negotiat ing the types of analyses on samples it allows to be taken, and even denying inspectors access to specific places. Despite its qualms about several is sues—among them the size and role of the executive council (the treaty's ad ministrators), and the export control language in the draft text—the U.S. will likely sign the treaty. One indication is that U.S. negotiators "are now worry ing about treaty implementation," a U.S. official says. Lois Ember
believes costs to depolymerize and reuse the Bexloy Κ fenders will be com petitive with costs of using virgin material. With environmental groups clamoring for greater use of recycled materials, Du Pont's public relations ploy in outfitting the tall ship seems aimed at demonstrating that recycled polymers are not neces sarily destined for inferior products. "We must remove the secondhand stigma associated with recycled ma terials and show they can perform in many applications as well as virgin materials," says Archie W. Dunham, senior vice president and chairman of Du Pont's Environmental Leader ship Council.
Rail benzene spill forces major evacuation A derailed tankcar last Tuesday fell 135 feet from a trestle into a Wisconsin river, cracking open and spilling most of its 26,200 gal of benzene solution, and forc ing a 10-hour evacuation of more than 50,000 people. About 25 persons went to hospitals in Superior, Wis., and Duluth, Minn., complaining of dizziness, head aches, and burning eyes and skin, after a noxious gas cloud enveloped low-lying areas. The vapor was dispersed later that day by wind and rain. The spill occurred as a 54-car Burling ton Northern train crossed the Nemadji River, which empties into nearby Lake Superior. Of the 14 cars that derailed, three were carrying chemicals from Cana da-based Novacor Chemicals to the Gulf Coast. One was the tanker that cracked JULY 6,1992 C&EN
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NEWS OF THE WEEK open, bearing a benzene solution containing about 13 products. The other two were a car with liquid petroleum gases and one bearing butadiene, which both fell on the river bank. Only the benzene tanker leaked, Novacor's corporate safety and emergency planning manager, Stanley T. Dodds, tells C&EN. A Chemical Manufacturers Association spokesman says ChemTrec, CMA's emergency hotline, responded to calls for information from area police and emergency response teams within hours of the derailment. The Coast Guard is supervising cleanup of the spill, which threatens local drinking water and area fish. The National Transportation Safety Board and Federal Railroad Administration are investigating the spill. Marc Reisch
The helium-nitrogen compound forms when a mixture of helium and nitrogen at room temperature is pressurized to 77 gigapascals, or 77,000 times atmospheric pressure. The mixture is squeezed between two flat diamond surfaces inside a high-pressure device called a diamond-anvil cell. The researchers were able to photograph the growth of a single microcrystal and to measure its x-ray diffraction pattern. Their results indicate its structure is distinct from that of any of the known highpressure phases of pure nitrogen and helium. The group now is trying to obtain He(N 2 ) n 's x-ray crystal structure. Vos hasn't yet completely mapped out the limits of the compound's stability. But he believes it probably is stable at much lower pressures if the temperature is lowered. He also is checking helium-argon, helium-xenon, and hydrogen-xenon mixtures to see if they form similar van der Waals compounds. One inorganic chemist consulted by C&EN questions whether He(N 2 ) n can A newly discovered family of cellreally be called a compound, since it surface proteins called neurexins, found lacks covalent bonds. David A. Young, only in the brain, may play a major role a theoretical physicist at Lawrence in formation and maintenance of synLivermore National Laboratory in Caliapses—the junctions between nerve cells fornia, agrees He(N 2 ) n is not a comwhere signal transmission occurs. The pound in the classical sense. It is more finding appears in the July 3 Science [257, like a packed assembly of different-size 50 (1992)] by molecular geneticists Yuri marbles, he says. A. Ushkaryov, Alexander G. Petrenko, Martin Geppert, and Thomas C. Sudhof Young, who has seen Vos' paper, exof the University of Texas Southwestern plains that He(N 2 ) n represents a stoichiMedical Center, Dallas. Researchers unexpectedly have pro- ometric ratio in the helium-nitrogen The specificity of synaptic connections duced a solid compound of helium and phase diagram that is unusually stable. is a major determinant of brain function. nitrogen at room temperature under The He and N 2 "marbles," he says, arrange themselves in a 1:11 array because However, little is known about how d e very high pressure. veloping nerve cells form synaptic conThe material—He(N2)n—is the first that leads to an energy mirrimum. This nections with each other, or how those solid compound of helium to be report- special packing arrangement apparently connections are maintained in mature ed. However, unlike other compounds is seen only at high pressure. "If you retissue, where dendrites and axon termi- involving noble gases, which contain co- lease the pressure, the compound goes nals are believed to continually retract valent bonds, this one is held together by away," Young says. and regrow. 'The simplest way to ex- a combination of pressure, packing forcThe chemistry of such simple van plain the specificity of synaptic connec- es, and relatively weak dipole-based in- der Waals compounds "may be importions would be that the proteins respon- teractions known as van der Waals forc- tant for understanding the structure sible for their establishment and mainte- es. The new material appears to be the and properties of the interiors of the nance might be polymorphic [capable of first of a novel family of van der Waals outer planets and their satellites, where taking many forms] and localized to compounds formed at high pressures. pressures are high and such componerve endings/' the researchers say. The research is detailed in last week's nents may be abundant," note Vos and Neurexins are the first proteins found Nature [358,46 (1992)] by chemical phys- coworkers. Adds Young: "We need to that appear to fit the bill. First, they are icist Willem L. Vos of the Geophysical know more about the behavior of solid, encoded by two or more genes that can Laboratory of the Carnegie Institution of icy mixtures at high pressure" that potentially generate more than 100 dif- Washington (D.C.) and coworkers there may exist inside some moons in the ferent neurexins by using alternative and at the University of Amsterdam. A outer solar system. And Vos' paper "is promoters (different start sites for DNA French group has discovered a related, a very interesting statement about transcription) and variably spliced exons high-pressure compound of helium and what might happen under those condi(different ways of arranging protein cod- neon (NeHe2), but their report hasn't yet tions of pressure and composition." Ron Dagani ing regions on the genes). Second, neu- been published.
Family of proteins may play key role in brain
rexins are found only in brain tissue, and tests indicate they are probably localized in synapses. And, they contain sequences similar to those found in several other proteins believed to play a role in axon guidance and synapse formation. 'The polymorphic structure of the neurexins, their neural localization, and their sequence similarity to proteins associated with neurogenesis suggest a function as cell-recognition molecules in the nerve termini," the researchers say. The scientists found the neurexins in an interesting way—by working backward from ot-latrotoxin, a component of black widow spider venom. a-Latrotoxin binds to receptors in presynaptic nervecell membranes, causing massive neurotransmitter release. When the researchers screened a complementaryDNA library for clones encoding the receptor for oc-latrotoxin, they discovered the receptor belonged to a large family of novel proteins, which they named neurexins. They speculate that "neurexins may align synaptic vesicles in the nerve terminal with structures on the extracellular side of the synaptic membrane/' among other functions. Stu Borman
First solid helium compound found
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JULY 6,1992 C&EN
