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Prediction of mixed gas adsorption by the multisite Langmuir (MSL) theory is significantly improved by incorporating the multiregion adsorption (MRA) theory. The new model, called the multiregion multisite Langmuir (MR-MSL) model, is thermodynamically consistent. MR-MSL uses the same pure-component isotherm parameters as MSL does, and no new parameters are introduced. Eight binary systems and one ternary system are used to test the MR-MSL model. For systems containing like components (such as mixtures of hydrocarbons and that of O2 + N2), MR-MSL yielded only minor improvements over MSL. This is true regardless of the magnitude of the differences in the pure-component MSL parameters among different components. For highly nonideal mixtures, MR-MSL results in very substantial improvements. It is also capable of predicting the azeotropic behavior of the adsorption of CO 2 + C3H8 on H-mordenite and the correct azeotropic compositions. For such systems, it is also shown that surface heterogeneity needs to be considered.

The mechanical behaviors of the self‐stressing steel slag aggregate concrete filled steel tubular (SSSACFST) stub column are investigated for practical structural applications. Twelve specimens under axial and eccentric compression are tested. The influences of different parameters, such as the eccentricity, the diameter–thickness ratio of the steel tube and the expansion rate of the steel slag aggregate concrete (SSAC) are studied. The experimental results show that the shear and the bending deformation dominate the failures of the specimens under axial and eccentric compression, respectively. The column with a high diameter–thickness ratio has a low ultimate bearing capacity and ultimate strain. The incremental range of the load capacity and the ultimate axial and circumferential strains of the specimens will be increased by raising the expansion rate of the SSAC. Based on the experimental results, the applicability of the current concrete filled steel tube design provisions for the SSSACFST stub columns is evaluated, and two analytical models for predicting the bearing capacity of the SSSACSFT stub columns under axial and eccentric compression are proposed.

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