The Chemical World This Week RESEARCH & TECHNOLOGY
MAY is, 19 β A
CONCENTRATES
• Deposition of silicon oxide films on silicon without changing electrical properties of the silicon is possible via a technique devised by Dr. Joseph R. Ligenza of Bell Telephone Laborato ries. The oxide films can be used to protect the silicon's surface and to prevent electrical leakage in silicon devices. Dr. Ligenza has grown a 6000A. coat of vitreous silica on silicon in one hour at 270° C. A steam process used for the same pur pose requires 1050° C. At the higher tempera ture, high-resistivity silicon's conductivity changes and its p-n junctions are displaced. In the new process, a silicon anode extracts species of nega tive ions from an oxygen plasma. • A new nuclear fragment, the C resonance, has been found by physicists at European Organization for Nuclear Research (CERN, in Geneva) and the Nuclear Physics Laboratory of the Collège de France ( Paris ). The CERN physicists say that the C° may be the first in a new group of subnuclear fragments. The new particle has a mass of 1230 m.e.v./c 2 and a lifetime of ΙΟ -20 second. It seems to have a spin (angular momentum) of 1 and positive parity. The European physicists used CERN's accelerator to project protons with an energy of 18,000 m.e.v. onto a beryllium target. Under bombardment, the target emits numerous "secondary" particles, among them antiprotons. The antiprotons are channeled toward a liquid-hydrogen bubble chamber detector 81 cm. long. The scientists observed 700,000 antiprotons in 300,000 photo graphs taken with the chamber. Of these antiprotons, 770 were annihilated with protons, pro ducing simultaneously a neutral kaon and the C° resonance. The latter rapidly disintegrates into another neutral kaon and a pair of pions, one posi tive and one negative. • Beryllium disk brakes and valve spring retainers have been fabricated at Brush Beryllium (Cleveland, Ohio). The nickel-plated beryllium disks and beryllium support linings reduce weight of each brake by 9 pounds. Beryl lium, with a density of 0.066 pound per cubic inch, reduces by 70% the weight of a part designed to absorb the same amount of heat as a steel part. The metal's specific heat is 0.46 B.t.u. per pound per ° F., compared to 0.12 for steel. In addition, beryllium dissipates heat faster than steel because its thermal conductivity (104 B.t.u. per square foot per hour) is four to seven times greater than steel's, Brush says. Conventional brakes last only
175 miles under racing conditions; the beryllium brakes lasted through a 200-mile race recently after having already gone through testing and qualifying. Light weight and high strength of the beryllium valve retainers increase engine power without a valve float problem. • À structural adhesive that does away with the need for removal of rust-inhibiting oils from metal surfaces has been developed at Goodyear. The one-component, nonsag adhesive (called Pliogrip AD-1033) bonds metals without the usual solvent degreasing that removes mill oils, according to Robert S. Savage, manager of Goodyear chemical division's adhesives department. It cures at 350° F. The adhesive also can bond dissimilar metals because it is flexible enough to absorb thermal stresses that result from differences in coefficients of expansion, Mr. Savage says. The adhesive is intended for use in automatic assembly of lightweight metal structures such as vending machines, refrigerators, ranges, and automobile hoods, deck lids, and doors. • A study of radiation problems that may be met by man during space flights is being started by the Oak Bidge Institute of Nuclear Studies ( OWNS ) for the National Aeronautics and Space Administration. The program, by ORINS' medical division, will include clinical and preclinical research, medical physics, and training. The division will also try to become a repository of information concerning radiation effects in man. Subjects that will be included in the program are radiation accident cases; therapeutic radiation of the entire body; and animal studies. Information that will be developed will cover the effects of various doses of irradiation on performance; early and late damage to the health of an astronaut; and ways to prevent and treat radiation damage.
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A facility for studying living organisms under a wide range of controlled environments will be built at the University of Wisconsin, Madison. Known as the Biotron, the facility will cost $4.2 million. Work will start this summer and be completed by fall of 1966. Scientists will be able to study plants and animals in 50 controlled environment rooms. Equipment will control pressure, temperature, air velocity, and light to reproduce almost any climatic condition ( including rain and snow). MAY 18, 1964 C&EN
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