News of the Week science technology division. The 100-Mg sample of einsteinium—at the moment, the noncommunist world's entire supply—that was analyzed by the researchers was provided by Richard Haire, a staff scientist at Oak Ridge National Laboratory. To make their measurements, Ward and Kleinschmidt use a Knudsen diffusion system built specifically to handle very small samples. The metal under study is placed in a cell and heated to different temperatures long enough to establish an equilibrium between the metal and its vapor phase. The cell has a hole in it that is small enough that vapor leaking from it does not alter the equilibrium. The metal vapor that escapes is deposited on a target or directed into a mass spectrometer.
From the amount of metal that escapes, the researchers can determine the vapor pressure in the cell. ' T h e vapor pressure gives us the heat of vaporization, which is effectively the cohesive energy of the material," Ward says. "Once we have that, we can do the complete thermodynamics of the solid, liquid, and gas over the temperature range of the measurement." The researchers previously have used the system to determine the properties of americium, curium, berkelium, and californium—elements that, in the future, could be produced in fast breeder reactors. They believe that einsteinium is the last element they will be able to analyze because of the very short half-lives of the higher-number, transplutonium elements. •
Ammonia detector uses reversible dye A small, reusable detector made of inexpensive, off-the-shelf components that can detect ammonia gas at concentrations of less than 60 ppm has been developed by researchers at the Naval Research Laboratory in Washington, D.C. Physicist John F. Giuliani, principal investigator on the project, and N. Lynn Jarvis, section head, say the heart of their system is a small glass capillary tube coated on the inside with an ammonia-sensitive dye, oxazine perchlorate. At one end of the tube they have fitted a small green light-emitting diode. At the other end is a phototransistor detec-
NRL's Giuliani tests sensitivity of optical waveguide ammonia detector, which is enclosed in a small column 8
February 7, 1983 C&EN
tor. The whole system works as a multiple reflecting waveguide device. The system in its present state of development is not really portable, Guiliani says, but with further development he believes a portable unit can be made. One of the chief advantages of the new system, he says, is that the dye used to detect the presence of ammonia is a reversible one. Thus, the unit can be used repeatedly. Its sensitivity is limited by the dye's sensitivity to water vapor. In dry air, the unit can detect concentrations of ammonia as low as 10 ppm, but at more normal 50% relative humidity, the sensitivity decreases to about 60 ppm. Even this level, however, is low enough to satisfy requirements of the Occupational Safety & Health Administration, Giuliani says. An added bonus, the researchers find, is that their dye is also sensitive to hydrazine, a toxic gas of particular importance to the Navy because it is used as a rocket propellent. The researchers are trying to develop other chemical microsensors whose detection is based on very small changes in the acoustic or electrical properties of coatings. The work is funded jointly by the Army and Navy. •
Tax rule may harm corporate R&D in U.S. Large, high-technology industries in the U.S. will increase their research and development spending at foreign facilities to the detriment of R&D spending in the U.S. if a moratorium on a particularly vexing tax regulation is allowed to expire this year. That is the main conclusion of a report sponsored by four major U.S. trade associations on the effects of Internal Revenue Service rule 1.8618, a rule issued in 1977, but put on hold by Congress in 1981. The intent of the report is to convince a potentially reluctant Congress that the regulation must be repealed soon. A similar study of the rule is supposedly being done by the Treasury Department, but it was due a year ago and still shows no sign of appearing. Bills are expected to be introduced soon in both houses of Congress calling for repeal. This rule basically says that companies that do business internationally (not just research) must apportion part of their R&D expenditures in the U.S. to the costs of their foreign operations, making that portion of expenses not deductible as a normal business expense. The report is based on a study by Arthur Andersen & Co., in which 85 of the largest U.S. multinational firms were surveyed on their R&D spending, both in the U.S. and overseas. These firms account for more than one third of all private U.S. R&D s p e n d i n g . The study found that in the past decade, foreign investment in R&D by the 53 interviewed corporations that do overseas research had risen 66%, whereas R&D in the U.S. had risen just 42% for the same firms. One of the reasons cited was rule 1.861-8. Another, and often bigger, reason given for larger foreign R&D spending is the tax incentives being offered by other nations. Sponsoring the study were the National Association of Manufacturers, the Electric Industries Association, the Emergency Committee for American Trade, and the Pharmaceutical Manufacturers Association. •
