Bu-Ali Sina University

About: Bu-Ali Sina University is a education organization based out in Hamadan, Hamadān, Iran. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 4078 authors who have published 7969 publications receiving 122828 citations.

An investigation on the energy absorption characteristics of multi-cell square tubes

Abstract: Due to increasing applications of thin-walled structures, especially as energy absorber, considerable researches have been made about them In this paper, firstly, behavior of simple and multi-cell square tubes with equal cells is studied analytically, experimentally and numerically Then, it is shown that for 3×3 square tubes with unequal cells, adding the partitions at corners increases energy absorption capacity of the tubes Furthermore, the Zhang's formula for prediction of mean crushing load (MCL) is revised to inclusion of unequal cells square tubes; then, analytical and numerical results are validated with experiments Finally, it is shown that the energy absorption capacity of the proposed new multi-cell square section is about 227% greater than that of simple section

Removal of heavy metals from aqueous solutions using sunflower, potato, canola and walnut shell residues

Abstract: In this research, the residues of sunflower, potato, canola, and walnut shell were used as sorbents to sorb heavy metals (Fe, Mn, Zn, Ni, Cu, and Cd) from aqueous solutions using batch experiments. The effect of pH and contact time was investigated. Maximum sorption of heavy metals by different sorbents was observed around pH 4–8. The optimal contact time was in the range of 20–600 min. The values of pHzpc (zero point of charge) measured for sunflower, potato, canola, and walnut shell residues were 6.06, 6.80, 6.15 and 5.85, respectively. The plant residues showed considerable capacity for removal of Fe, Mn, Zn, Cu, and Cd from aqueous solution but Ni sorption by residues was negligible. Chemical activation of sorbents with NaOH enhanced Ni sorption. Competitive sorption decreased the removal of heavy metals compared to the single system. The Langmuir isotherm model fitted well to experimental metals sorption. The sorption kinetic of heavy metals was described well by pseudo second order model. In our study, the sorption mechanisms such as electrostatic attraction and ion exchange as well as complexation seem to be the most occurring phenomena.