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Line Tension (line + tension)

Distribution by Scientific Domains
Chemistry75%

Selected Abstracts

Theoretical study of wetting behavior of nanoparticles at fluid interfaces

AICHE JOURNAL, Issue 3 2009
Jianguo Mi
Abstract In this work, a theoretical model was developed to describe the wetting behavior of nanoparticles at liquid-vapor interface by the integration of the renormalization group transformation, the cell theory, and the modified fundamental measurement theory with the first-order mean spherical approximation method. The results show that the new model can be used to investigate the global behavior and surface tensions of nanoparticle/fluid systems. Particularly, the nanoparticle's wetting behavior inside critical region was discussed systematically. More important, this work proposed a methodology for calculating line tension and contact angle, showing that line tension has considerable influence on wetting properties for small nanoparticles, whereas it is negligible for large nanoparticles. Therefore, this work provides a general method for studying the wetting behavior of nanoparticles that may find wide applications in the field of chemical engineering. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Effect of hydrogen on electronic structure of fcc iron in relation to hydrogen embrittlement of austenitic steels

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 12 2007
S. M. Teus
Abstract The total structural energy per primitive lattice cell, density of electron states, spatial distribution of electrons and elastic modulus in fcc Fe,H solid solutions are studied using the density functional theory and Wien2k program package. It is shown that hydrogen increases the density of electron states at the Fermi level. The density of conduction electrons is increased in the vicinity of hydrogen atoms, which suggests that the latter migrate over the crystal lattice surrounded by the clouds of conduction electrons. Calculations of elastic modulus show that hydrogen decreases the shear modulus c44. The consequences for mechanical properties of hydrogen-charged austenitic steels are analysed taking into account the stress for activation of dislocation sources, the line tension of dislocations and the distance between dislocations in pile-ups. It is concluded that hydrogen-induced brittleness of austenitic steels can be satisfactorily interpreted in terms of the hydrogen effect on the electronic structure. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Growth process of the ridge,trough faces of a twinned crystal

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 4 2005
Jae-Wook Lee
For a twinned face-centered-cubic crystal, the energy barrier for two-dimensional nucleation on a concave trough (or a re-entrant edge) and that for a layer advancing across a convex ridge were calculated. The former was obtained by analyzing the line tension of the trough. The results show that their energy barriers are 39 and 50% compared to that for nucleation on a flat {111} face, respectively. Therefore, the layer advance across the ridge is found to be more difficult than the nucleation on the trough. Based on these results, the morphology of the growing surface is predicted and an alternative growth process by the twin-plane-re-entrant-edge mechanism is suggested. [source]