M. Goodarzi and A. R. Azimian,
Volume 22, Issue 2 (1-2004)
Abstract
For implementation
of the free surface boundary condition, a new subroutine has been introduced to an existing steady 3-D body fitted code. This code was previously written for steady flow simulation in closed ducts. The algorithm used in this subroutine reduces the instability problem according to the free surface wave generation. For code validation, it was applied to two different open channels. The results obtained for these test cases were compared with existing data. The comparison of the two sets of data was promising and proved that with this subroutine it is possible to predict the free surface position very well. The results of this routine were also compared with the symmetry boundary condition at the free surface for two mixing flows and it showed that, if the changes of the free surface elevation were small, the symmetry boundary condition could be considered as an accurate enough method
A. Mehdikhani, H. Fallah-Arani, F. Dabir, A. Ghanbari,
Volume 41, Issue 2 (11-2022)
Abstract
In this research, the effect of hydrogen peroxide (H2O2) and benzoyl peroxide (BPO) on the structural properties, porosity, active pores, and surface area of the MOF-5 (Zn4O(BDC)3) metal-organic framework was studied. For this purpose, the metal-organic framework was synthesized by direct mixing and the molar ratios of the precursors to the ligand were modified to minimize the stoichiometric calculation error as well as the washing process to improve the properties of the synthesized MOF-5. In order to characterize the synthesized compounds and to investigate the effect of peroxides and washing process on the properties of the samples, X-ray diffraction (XRD), fourier Transform infrared spectroscopy (FTIR), and thermogravimetric/Differential scanning calorimetry (TG-DSC) analysis were performed. Structure, pore volume (1.212 cm3/g), and specific surface area (2307 m2/g) were compared to the sample synthesized with H2O2. DM-P-03 was selected as the optimal sample and prepared for thermal stability. According to TG-DSC analysis, the remaining zinc compounds in the sample were checked and the thermal stability of MOF-5 structure was confirmed up to 470°C.
