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In this paper, nominal compositions of NdFeAsO 0.8 F 0.2 , NdFeAs 0.95 Sb 0.05 O 0.8 F 0.2 and NdFeAs 0.95 P 0.05 O 0.8 F 0.2 were prepared by one-step solid-state reaction method. The structural, electrical and morphological properties of samples were characterized through the XRD pattern, the 4-probe method and SEM, respectively. The crystal structure of our samples was tetragonal with P4/nmm:2 symmetry group. Also, the (x, y, z), occupancy of ions and lattice parameters were changed by isovalent substitution of Phosphorus (P) and Antimony (Sb)in the NdFeAsO 0.8 F 0.2 sample. The ⍺, β bond angles and Fe-As bond length are changed from the corresponding value of ⍺ and β regular FeAs4-tetrahedron by isovalent doping P/As and Sb/As, that they are effective on the superconductivity transition temperature. The microstrain and crystalline size of samples were studied by the Williamson Hall method. The superconducting critical temperatures were attained at 56 K and 46 K for NdFeAsO 0.8 F 0.2 , NdFeAs 0.95 Sb 0.05 O 0.8 F 0.2 , respectively. The NdFeAs 0.95 P 0.05 O 0.8 F 0.2 showed the structural transition temperature at 140 K. It seems that there is a relation between the superconductivity and shrinkage of the crystal lattice. The flake-type of grains was observed by SEM pictures of samples.

Two different types of hollow‐fiber membrane contactors were used for CO2 separation from the gas stream with monoethanolamine (MEA) absorbent and numerically investigated. After the model validation with experimental data, CO2 removal efficiency, MEA concentration, and pressure drop variation were examined under different conditions by variation of some effective parameters such as gas stream velocity, absorption solution velocity, membrane porosity, and membrane tortuosity. Membrane tortuosity and porosity enhancement led to light decrease and light increase in CO2 removal efficiency, respectively, but gas stream velocity enhancement significantly reduced the CO2 removal efficiency.

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