Bartel

The relationship between the shape-dependent quantity H and the experimentally measurable quantity S originally was determined empirically [66], but a set of quite accurate XjH versus S values were later obtained by Niederhauser and Bartell [67] (see also Refs. 34 and 68) and by Stauffer [69],... 

J. M. Andreas, E. A. Hauser, and W. B. Tucker, J. Phys. Chem., 42, 1001 (1938). D. O. Niederhauser and F. E. Bartell, Report of Progress—Fundamental Research on the Occurrence and Recovery of Petroleum, Publication of the American Petroleum Institute, The Lord Baltimore Press, Baltimore, 1950, p. 114. 

The equilibrium shape of a liquid lens floating on a liquid surface was considered by Langmuir [59], Miller [60], and Donahue and Bartell [61]. More general cases were treated by Princen and Mason [62] and the thermodynamics of a liquid lens has been treated by Rowlinson [63]. The profile of an oil lens floating on water is shown in Fig. IV-4. The three interfacial tensions may be represented by arrows forming a Newman triangle ... 

Donahue and Bartell verified Eq. IV-16 for several organic alcohol-water systems. 

Small metal clusters are also of interest because of their importance in catalysis. Despite the fact that small clusters should consist of mostly surface atoms, measurement of the photon ionization threshold for Hg clusters suggest that a transition from van der Waals to metallic properties occurs in the range of 20-70 atoms per cluster [88] and near-bulk magnetic properties are expected for Ni, Pd, and Pt clusters of only 13 atoms [89] Theoretical calculations on Sin and other semiconductors predict that the stmcture reflects the bulk lattice for 1000 atoms but the bulk electronic wave functions are not obtained [90]. Bartell and co-workers [91] study beams of molecular clusters with electron dirfraction and molecular dynamics simulations and find new phases not observed in the bulk. Bulk models appear to be valid for their clusters of several thousand atoms (see Section IX-3). 

Bartell and co-workers have made significant progress by combining electron diffraction studies from beams of molecular clusters with molecular dynamics simulations [14, 51, 52]. Due to their small volumes, deep supercoolings can be attained in cluster beams however, the temperature is not easily controlled. The rapid nucleation that ensues can produce new phases not observed in the bulk [14]. Despite the concern about the appropriateness of the classic model for small clusters, its application appears to be valid in several cases [51]. 

This distinction between 7 s and 7svo seems first to have been made by Bang-ham and Razouk [33] it was also stressed by Harkins and Livingstone [34]. Another quantity, introduced by Bartell and co-workers [35] is the adhesion tension A, which will be defined here as... 

Ruch and Bartell [84], studying the aqueous decylamine-platinum system, combined direct estimates of the adsorption at the platinum-solution interface with contact angle data and the Young equation to determine a solid-vapor interfacial energy change of up to 40 ergs/cm due to decylamine adsorption. Healy (85) discusses an adsorption model for the contact angle in surfactant solutions and these aspects are discussed further in Ref. 86. 

Bartell and co-workers report the following capillary pressure data in porous plug experiments using powdered carbon. Benzene, which wets carbon, showed a capillary pressure of 6200 g/cm. For water, the pressure was 12,000 g/cm, and for ben-... 

Two approaches of this type, purporting to give absolute surface areas, might be mentioned. Bartell and Flu [19] proposed that the heat of immersion of a powder in a given liquid... 

Bartell and Flu [19] were able to determine the adhesion tension, that is, ysv -7SL. for the water-silica interface to be 82.8 ergs/cm at 20°C and its temperature change to be -0.173 erg cm K . The heat of immersion of the silica sample in water was 15.9 cal/g. Calculate the surface area of the sample in square centimeters per gram. 

J. J. Bartel, H. J. Rack, R. W. Mar, S. L. Robinson, E. P. Gersde, Jr., and K. B. Wischmann, 1. Molten Salt and Eiquid Metal, Sandia Eaboratories Materials Fast Group Keview of Advanced Central Eeceiver Preliminary Designs, Sept. 1979, SAND 79-8633, available from National Technical Information Service, Washington, D.C. 

References Parfitt (ed.). Dispersion of Powders in Liquids, Elsevier Applied Science Publishers Ltd., 1986. Washburn, Phys. Ren, 17, 273 (1921). Bartell Osterhof, Ind. Eng. Chem., 19, 1277 (1927). 

Graphite [7782-42-5]. Treated with hot 1 1 HCl. Filtered, washed, dried, powdered and heated in an evacuated quartz tube at 1000° until a high vacuum was obtained. Cooled and stored in an atmosphere of helium [Craig, Van Voorhis and Bartell 7 Phys Chem 60 1225 1956]. 

Lysne, P.C., Graham, R.A., Bartel, L.C., and Samara, G.A., Solid State Research and Application Series, VII. Shock Wave-Induced Phase Transformations A Review of the Field, Sandia Laboratories Technical Memorandum No. SC-TM-710907, Albuquerque, NM, 64 pp., December 1971. 

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