I&EC TRENDS TODAY A vapor-pressure standard for measuring cryogenic temperatures (between 0.3' and 3.2" K.) is o$ered as high purity helium-3 formed by the disintegration of the excited state of lithium. Lithium-7 formed from neutron-bombarded lithium4 disintegrates into helium-4 and tritium. The decay of tritium results in the formation of helium-3 and a low energy particle. Developed by Monsanto's Isotope Diu. under license from the AEC, the material is useful as a cryogenic bath, as a projectile in high energy nuclear research, and as a neutron detector. Heat to convert sea water to fresh water will be supplied by the incineration of refuse. The town of Hempstead, L. I., has contracted with A M F ' s M a x i m Diu. to purchase four heat recovery evaporators which could provide up to 450,000 gallons of fresh water per day. The units constructed of nickel-copper alloys and other nonferrous metals will supply the town with water containing less than 1Op.p.m. of salts. Use of this water to minimize fly ash is expected to control air pollution and to decrease scaling and corrosion in the steam generating equipment. For advanced cryogenic system design, correlation and compilation of experimental data and property tables for cryogenicfluids is expected to provide the basis for tabulations of thermodynamic properties. Property tabulations of cryogenic fluids, available at the NBS Cryogenic Center in Colorado, are based on the existing data which have been extrapolated to higher pressures and lower temperatures. Data weighted and collected from individual laboratories and researchers plus the use of generalized equation of state have been used to represent PV T data and thermodynamic properties of helium, parahydrogen, neon, carbon monoxide, oxygen, and argon. These compilations have indirectly benefited investigators by defining those areas where additional experimental data on cryogenicfluids are needed. Super refractory zirconia fibers for high temperature requirements of rocket engine propellants and re-entry space vehicles have been developed by H. I. Thompson Fiber Glass Co. Thesejbers with low conductivity and high melting points can be molded by any conventional process into ablative and insulative componentsfrom 3000' to 4000 O F. service. The fibers with a circular cross section range in diameter from 0. 1 to 0.3 mil and are now being processed in the forms of paper, batting, and foamlike solids. The government program is continuing to develop and produce zirconia jbers of truly continuous length. New concepts in chemical engineering are gaining momentum, according to Professor P . Le Go$ of the University of Nancy (France) in an article in the December 1963 issue of Genie Chirnique. Professor Le Go$ sees modern chemical engineering as bridging the gap between the thermodynamic, kinetic, and atomistic asFects of physical chemistry, on the one hand, and the traditional Unit Operations on the other. The bridges are six groups of mathematical relations: principles of conservation of extensive properties; laws of static equilibrium; kinetic laws of change; capacitive relations of speciJic extensive properties; economic balances; and principles of optimization. Probably the most important group is that containing the kinetic laws of change which include transport of matter and energy within a phase, transfer of matter and energy between phases, and the transformation of matter and energy without displacement. Professor Le Go$'s description is one of the f e w comprehensive attempts, to date, to identifr the scope of modern chemical engineering. VOL. 5 6
NO. 3
MARCH 1964
7
10 reasons why vour comDetitor alreadv sent for samdes of
phone for yours Phone? Sure! It's not every day a new modified-acrylic latex for exterior paint is introduced. Especially one that offers ten specific advantages over polyacrylate latices. And that's exactly what A C R Y L E N E ' ~ 4 5 does. So read on . , . when you're convinced, dial our number collect, 1 . Chalking? Easily controllable. Pigments and ACRYLENE 45 love each other. They must, the way they hang together. 2. Peeling? ACRYLENE 45 adheres to most surfaces , . . and adheres to stay. 3. Lim-
ited formulations? A 20% increase i n solids content to 56% gives you much wider formulation latitude. 4. Trouble with new stucco? ACRYLENE4 5 has excellent alkali resistance. 5. PVC giving you the profit squeeze? Your Pound Volume Cost is reduced with a new low in specific gravity . . . ACRYLENE45 1.05 vs 1.15for polyacrylic latices. 6. Fading out of the m a r k e t ? 1000-hour fadeometer tests prove the ercelient tint retention of new 45. 7. Additives adding more ACRYLENE
cost than color? ACRYLENE 45 permits full color development with low surfactant 45 levels. 8. Short surface life? ACRYLENE has excellent initial film flexibility and elongation retention that give long-service surface with low film embrittlement. 9. ACRYLENE45 is low-foaming. And 10. . . . non-yellowing; whites stay white longer. Phone for samples today: 216-7943310. Or, i f o u r l i n e i s busy, w r i t e : Goodyear, Chemical D a t a Center 0-20, P.O. Box 9115, Akron, 0 . 4 4 3 0 5 .
CHIEMICALS -
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Circle No. 41 on Readers' Service Card
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INDUSTRIAL A N D ENGINEERING C H E M I S T R Y
I&EC TRENDS
INDICATORS FOR TOMORROW Optical devices which r'see" and "read," predicted almost a decade ago, may be developed more rapidly because of an advance in optical spatial filtering technology reported from Michigan University's Institute of Science and Technology. The experimental device consists of a conventional coherent optical processing system with a modijed arrangement of interferometers and a gas laser light source which gives a beam that can be manipulated to permit the recording of certain vital light factors on ordinary photographic film. The Institute has developed a technique which simultaneously produces the required phase information and records it on ordinary photographic film without the use of auxiliary phasejlters. The required complex spatial jilter may then be easily constructed for an arbitrary two-dimensional shape; with a simple modijication, the processing system may also use its own components to construct the required filter directly from the object to be recognized.
has been demonstrated by Westinghouse's Aerospace Diu. The pump, a specially designed cathode ray, contains a laser crystal and standard electron tube cathodes arranged in a coaxial design. Electrons accelerated through a high potential bombard a special phosphor Jilm which emits light required to excite neodymium ions in the laser. The pumping light brings the internal energy of the atoms to an excited state to provide a means of controlling and operating a laser ouer a wide range ofpulse lengths from microseconds to continuous wave operation. This control factor is claimed to make the technique useful for long range radar and communications equipment. Cathodoluminescent pumping with a solid-state laser
Two chemicals, P-Fe203and y-FezOs, available in aquasol and organosol dispersions, range in particle size from 2 to 12 millimicrons. These sols, according to Diamond Alkali's M . W. Jackson, have demonstrated a stability for periods in excess of 2 years and have possible use as transparent colorants, as liquid cores for heat dispersion in high frequency electrical equipment, and as materials for magnetic tapes and inks. The superparamagnetic y variety prepared in a 30% concentration aquasol and a 40% dispersion in hydrocarbons such as kerosine, toluene, or xylene can be included in plastics to impart magnetic properties without accompanying electrical conductivity .
A comparatively stable auto-ionizing state of electrons has been discovered by physicists R. Novick and P. Feldman of Columbia University. In the new state, electrons occupy an unusual class of unstable orbits for as long as a f e w millionths of a second compared to previously known orbits that last only a f e w billionths of a second. This long-lived auto-ionizing state owes its comparative stability to the shape and symmetry of its orbit in which the electrostatic forces between electrons in the atom average zero. The new state is expected to shed new light on the forces that bind protons and neutrons together and to more accurately portray atomic structure. Use of plasma to create new types of materials through the combination of subcolloidal sizes of metal particles with those of plastics and ceramics is being investigated by Quantum, Inc., of Connecticut. Early work done by the laboratory on plastimets (particulate combinations of metals andplastics) led C. M . Doede, president of Quantum, to regard plasma as a potential tool for making physical mixtures of metals and plastics, the properties of which would be something more than additive. Already polymers which withstand temperatures to 1000" F. have been synthesized. VOL. 5 6
NO. 3
MARCH 1964
9
