TRENDS
There is ioy as well as wonder in science, and a science writer makes eveiy effort to communicate as muchjoy as he can t o offer a balanced menu to the reader. Serve some solid, heavy food, but also some frothy French pastry. This is the summa?y of PValter Sullivan, Science Editor of the New York Times, in an article ” Writzng Science for the Public” (Physics Today, Vol. 23, N o . 8, August 7970, 51-53). A s our technology becomes more and more spectalized, interpretation for the public becomes close t o impossible. Therefore, the scientist and engineer have an obligation to improve the cornmunication of their technology to the public, so that the publzc appreciates the technology they use. I n thzs way any professzon can gain status and acceptance on a universal basis.
Numerical lreatment of multicomponent vapor-liquid equilibria by zs described by V . Sanchez, G. Guiglion, and J . Mahenc, Instztut du
a general method Genze Chimique, Laboratorie de Chimze Physique, 7 78 route de -Varbonne, 31- Toulouse-04, France (Chzm. Ind., Genze Chim.. V o l . 703, No. 70, June 1970, $161278-7284). The iterative ,Veaton’s method zs applwd to calculation of lzquid-vapor equilibria, using U’ilson’s equation. Illustrations are given concerning different binary and ternary systems. Further znformation is avazlable from the authors relative to the Fortran IV computer brograms developed in this study. Pressure vessel analysis may be made by uszng edge znjuence coeficzents. Engzneers leho are not famzlzar zezth the detazls of shell theory can use thzs method to obtazn accurate answers to pressuie vessel stress problems azthout expendzng a great deal of tzme zn the J. ( J . Eng. iMater.. Compi ocess. Wzllzam Grzfel, Pzcatznny Arsenal, Doz’er, ponents and Deszgn, Vol. 37, X o . 8, Aug. 7970. p p 981-983) has tabulated these coeflczents calculated from shell theory for cylznders and spherzcal caps of varzous dzmenszons. The author descrzbes the method azth a numerical example.
I n the study of a column of lzquzd vzbratzng vertzcally, bubbles of gas move downward and coalesce at the bottom of the contazner to form a slug that, after reachzng a suflciently large size, moues upward. E. Ruckenstezn and 0 . Muntean, Polytechnz Instztute of Bucharest, Romanza (Chern. Eng. Scz., Vol. 25, 7970,p p 7 759-1766)obtazn the veloczty dzstributzon zn the continuous Fhase for the movzng bubble and use the neloczty dzstributmn to predzct ttansfer rates. The velocity dzstrzbutzon for small Reynolds numbers around a bubble moving zn the zizbratzng lzquzd zs obtazned. B y using thzs zleloczty dzstrzbutzon, the tzme-dependent conziectzve dzfuszon equatzon zs solved by means of a szmzlarzty transformation, and an equation zs establzshed for the mass-transfer coeficzent.
Mass transfer rates are improved by sonic vibration.
according t o Theoretzcal @ Engineering Technzques Ltd., Lzttle Melton, Norwich, England. The component, called a ”Radfoil” can produce aerodynamic lift, reduce drag in fluid systems, pump lzquzds or compress gases, and propel marzne aessels, particularly submarmes. The mazn advantage of the Generating thrust in fluids i s now possible,
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
concept is that the disadvantages of a propeller-cavitation, for example-are eliminated. The component, based on the concept of j u i d i c switching in fluids, permits a designer to use an impeller rather than apropeller to provide axialjow (Prod. Eng., Vol. 47, No. 78, Aug. 31, 1970, p 32). Pulverized fuel ash (PFA) from power stations in the United Kingdom is being marketed for a diverse and growing list of uses. This gray powder, seemingly useless, is now being used in agriculture to mix with organic waste to give a material akin to soil. Also, this material is finding widespread use in civil engineering and building activities, particularly lightweight aggregate manufacture. Of the 70 million tons of this material produced in Britain annually, 40% goes into the building or civil engineering activities and the remainder is returned to the soil ( J .Rippon and E. J . Barger, Sci. J.,Vol. 6, No. 8, Aug. 1970, pp 74-79). W h a t was a waste material is today a valuable by-product for usefulpurposes; in addition, it is eliminating a pollution problem.
which varies reversibly with temperature, plays an important role in many solid state processes such as dzfusion, ionic conduction, and chemical reactions in the solid phase. Jens Nolting, Institut fur Physikalische Chemie der Universitat, 34, Gottingen, Burgestrasse 50, Germany (Angew. Chem., Int. Ed., Vol. 9, No. 7, 7970, pp 489-500) reviews the problems and possibilities for the determination of intriizsic disorder. The physical and chemical descriptions of the state of disorder are given, and the principle methods of investigation are discussed. The author places emphasis on methods o f determining disorder data from “anomalous” speciJic heats. Intrinsic disorder in crystalline solids,
in studying natural products poses a serious problem owing to the high cost of commercial j a s h evaporators. G . R. Pettit and F . Gruschweiler, Department of Chemistry, Arizona State University, Tempe, Arizona, have developed a useful, all g l a s s j a s h evaporator that can be constructed by a skillful glassblower in about two days, at a cost of less than $50. The authors present a diagram and symbol key that should allow the apparatus to be readily constructed [Chem. Ind. (London), No. 31, Aug. 7 , 1970,p 10181. Solvent distillation of materials encountered
in very small drops and letting the drops solidify as they fall. Jets of molten steel pour through fine nozzles into an atomization chamber. Nozzles blow high-speed jets of gas (argon) into the upper part of the chamber to break the steel sprays into showers of small droplets. The powders are compacted to form a uniform structure. The Stora Kopparberg Company of Soderfors, Sweden, is using this technique to produce steel powder with a grain size of about mm. Stora claims that steel produced from powder has many advantages over conventionally made steel ( N e w Sci., Vol. 47, No. 777, Sefit. 3, 7970,p 477). Also, completely new types of steel can be developed, in particular, steel with a high alloy content. Steel powder can be made by spraying molten steel
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