Hardy

Pande, S.G. and D.R. Hardy (1990), "A practical evaluation of published cetane indices". Fuel, Vol. 69. 

The idea that unsymmetrical molecules will orient at an interface is now so well accepted that it hardly needs to be argued, but it is of interest to outline some of the history of the concept. Hardy [74] and Harkins [75] devoted a good deal of attention to the idea of force fields around molecules, more or less intense depending on the polarity and specific details of the structure. Orientation was treated in terms of a principle of least abrupt change in force fields, that is, that molecules should be oriented at an interface so as to provide the most gradual transition from one phase to the other. If we read interaction energy instead of force field, the principle could be reworded on the very reasonable basis that molecules will be oriented so that their mutual interaction energy will be a maximum. 

Much of the classic work with boundary lubrication was carried out by Sir William Hardy [44,45]. He showed that boundary lubrication could be explained in terms of adsorbed films of lubricants and proposed that the hydrocarbon surfaces of such films reduced the fields of force between the two parts. 

Levine and Zisman [46] confirmed and extended Hardy s results, using films on glass and on metal surfaces that were deposited by adsorption either from... 

Hardy s explanation that the small coefficients of friction observed under boundary lubrication conditions were due to the reduction in the force fields between the surfaces as a result of adsorbed films is undoubtedly correct in a general way. The explanation leaves much to be desired, however, and it is of interest to consider more detailed proposals as to the mechanism of boundary lubrication. 

Fig. Xn-9. Contact region in boundary lubrication according to Hardy. (From Ref. 45.)...

This second picture, while an advance over Hardy s, again encounters difficulties. It does not suggest how A could be so much greater than A i or why Sf... 

W. B. Hardy, Collected Works, Cambridge University Press, Cambridge, England, 1936. 

Hardy W B 1912 The tension of composite fluid surfaces and the mechanical stability of films of fluids Proc. R. See. A 86 610-35... 

Schottky mechanism Schott nomenclature Schradan [152-16-9] Schreibersite [12424-46-3] Schugi mixer Schulze-Hardy rule Schwann cells Schwarzembergite Schwenzfeier process Science policy... 

Specifications and Analytical Methods. Butanediol is specified as 99.5% minimum pure, determined by gas chromatography (gc), sohdifying at 19.6°C minimum. Moisture is 0.04% maximum, determined by Kad-Fischer analysis (dkecdy or of a toluene a2eotrope). The color is APHA 5 maximum, and the Hardy color (polyester test) is APHA 200 maximum. The carbonyl number is 0.5 mg KOH/g maximum the acetal content can also be measured dkecdy by gc. 

D. F. W. Hardie, Electrolytic Manufacture of Chemicals from Salt, The Chlorine Institute, Inc., New York, 1975. 

Parsley (Parsley Flakes). The dried leaves of Petroselinum hortense syn. P. crispum (Mill) (UmbeUiferae), are from a hardy biennial, native to the Mediterranean region and now cultivated commercially in the United States and southern Europe. The aroma is green and the flavor is pleasant, characteristic, and nuld. Parsley is used for the seasoning of fish, meats, soups, salads, etc. Parsley seed, the dried ripe fmit of the parsley herb, has an aroma and flavor less pronounced than the leaves. 

R. C. Bums and R. W. F. Hardy, Nitrogen Eixation in Bactena and Higher P/ants, Springer-Vedag, Berlin, 1975, p. 43. 

C. W. Hardy and co-workers. Committee on Technology—Special Study Team on Refractories, Refractory Materials for Steelmaking International Iron and Steel Institute, Bmssels, Belgium, 1985. 

---