ŒÏÏEÏÏÏME Science
Laser enrichment of uranium in its 2 3 5 U isotope has been demonstrated on a microscopic scale, Lawrence Livermore Laboratory says. The technique involves aiming a laser beam and an ultraviolet light through a thin stream of vapor from a heated uranium sample. The laser selectively excites the electrons of only 2 3 5 U , enabling the UV light to ionize the atoms so that a negatively charged collector cup can attract them. In the experiment, Livermore scientists increased the concentration of 2 3 5 U from the natural abundance of 0.7% to more than 60%. Vegetarian diets can be nutritionally adequate if there is enough variety and if certain nutrients are included, according to a statement issued last week by the National Research Council's Committee on Nutritional Misinformation. With judicious mixing, the committee says, combinations of lower-quality protein foods can give about the same nutritional value as high-quality animal protein foods. Calcium, iron, riboflavin, and vitamin B12 are likely to be inadequate in all-plant diets, it says, and fortified soybean milk or a vitamin B12 supplement are necessary. Vitamin BQ may be a factor in liver tumors, say scientists at West Virginia University. Rats fed a diet deficient in vitamin BQ (pyridoxine) developed smaller tumors (about one half to one third the size) than did rats fed a diet containing pyridoxine. Other experiments have shown that withholding pyridoxine from rats with liver tumors increases the activity of an enzyme, tyrosine transaminase, in the liver. This effect is not seen in cancer-free rats. A slow, controlled-release drug treatment for glaucoma has been approved by FDA, according to the maker, Alza Corp., Palo Alto, Calif. Alza expects labeling approval shortly from FDA for its Pilo 20 and Pilo 40 Ocusert pilocarpine therapeutics, small laminates of several polymeric materials designed for insertion directly under the eyelid. Marketing will begin in about two or three months.
Technology Auto exhaust emissions don't increase linearly after a tune-up as is generally assumed, says Exxon Research and Engineering. In a one-year study of about 400 cars, Exxon scientists found that after emission control maintenance work, carbon monoxide emissions remain constant for about 12 months, and then rise rapidly, while hydrocarbon emissions rise sharply after the first few months before dropping to a plateau. Reactivation of the Project Gasoline pilot plant at Cresap, W.Va., will turn the plant into a multipurpose process testing facility. Fluor Corp. will operate the facility—closed four years ago—under a
three-year, $13 million contract from the Office of Coal Research. Emphasizing production of fuel oil for large industrial users and utilities, development work will include evaluation of numerous liquefaction processes, using both eastern and western coals. Fluor is already on site, determining necessary modifications. Natural gas production testing of the Project Rio Blanco nuclear-stimulated well is continuing. A new well will angle into the middle of three nuclear explosion zones to study the extent of fractures around that zone. Last fall, the project sponsors (AEC and industry) drilled back through the original well bore into the top explosion zone. Natural gas was produced from that zone, but no connection was found between the top zone and the two explosion zones below it. A new process for gas and oil recovery from shale can extract 100% of the oil assay value of the shale, according to Union Oil Co. of California. Union has nearly completed pilot testing of its gas and steam recycle process near Brea, Calif., and plans a larger, 1500 ton-per-day plant in Colorado later this year. Development of the process effectively increases the company's shale oil reserves by 15% through the more efficient recovery afforded by gas recycling. Union also says it is economically attractive enough to compete in a $13to $15.-per-barrel oil market. Research on technology for improving electric power production, transmission, distribution, and utilization is being boosted by the Electric Power Research Institute, which has approved sponsorship of 27 projects costing $5.1 million. The new funding, most of which is for research toward conversion of coal into gases and liquids for clean energy production, brings EPRI research projects now under management or in contract negotiations to 172, with a value of $178 million. A new optical fiber that transmits light with only about a 33% loss over a mile has been developed by Bell Telephone Laboratories. The glass fiber is made by a chemical vapor deposition technique, similar to that used in making semiconductors. The fiber is formed as gases passing through a fused quartz tube are heated to a temperature at which they react and are deposited on the tube walls. When enough core material has been formed, the tube is collapsed by further heating and drawn into the optical fiber. Synthetic materials for artificial organs will be investigated by Case Western Reserve University's Case Institute of Technology under a $2.5 million NI H grant, the largest program/project grant ever awarded to Case. The five-year, three-part program will involve synthesis and design of new soft materials; testing and evaluation of the materials' physical properties; and biological testing of the materials using blood clotting and tissue culture. June 17, 1974 C&EN
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