Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Transport Phenomena
A Mushy-Zone Rayleigh Number To Describe Interdendritic Convection During Directional Solidification Of Hypoeutectic Pb-Sb And Pb-Sn Alloys, Surendra N. Tewari, R. Tiwari
A Mushy-Zone Rayleigh Number To Describe Interdendritic Convection During Directional Solidification Of Hypoeutectic Pb-Sb And Pb-Sn Alloys, Surendra N. Tewari, R. Tiwari
Chemical & Biomedical Engineering Faculty Publications
Based on measurements of the specific dendrite surface area (S-nu), fraction of interdendritic liquid (phi), and primary dendrite spacing (lambda(1)) on transverse sections in a range of directionally solidified hypoeutectic Pb-Sb and Pb-Sn alloys that were grown at thermal gradients varying from 10 to 197 K cm(-1) and growth speeds ranging from 2 to 157 mum s(-1), it is observed that S-nu = lambda(1)(-1) S*(-0.33) (3.38 - 3.29 phi + 8.85 phi(2)), where S* = D-l G(eff)/V m(1) C-o (k - 1)/k, with D-l being the solutal diffusivity in the melt, G(eff) being the effective thermal gradient, V being the …
Gibbs Dividing Surface And Helium Adsorption, Sasidhar Gumma, Orhan Talu
Gibbs Dividing Surface And Helium Adsorption, Sasidhar Gumma, Orhan Talu
Chemical & Biomedical Engineering Faculty Publications
All adsorption data is based on the definition of Gibbs dividing surface, which is a purely mathematical transformation. Adsorption measurements in microporous solids necessitate experimental determination of the dividing surface. An international protocol does not exist on how to perform this important measurement. Commonly, helium is assumed not to adsorb and used as a probe molecule for this measurement. Each experimentalist chooses an arbitrary set of conditions, often without even disclosing them, which adds to the confusion in adsorption literature. Here, a self-consistent method for the analysis of helium data is proposed which does not assume non-adsorbing helium …