Determination of atmospheric concentrations of inorganic anions by ion chromatography following ultrasonic extraction

The capability of the suppressed conductometric detection ion chromatography (IC) was investigated for the separation and determination of inorganic anions (F-, Cl-, NO3- and SO4(2-)) in standard reference materials SRM-1648 urban particulate matter following ultrasonic extraction. The effects of the cationic surfactant (SDS) and the anionic surfactant (CTAB) on ultrasonic extraction efficiency of inorganic anions from complex matrix of airborne particulate matter were investigated. The results showed that surfactant can enhance the extraction efficiency. Finally, the concentrations of inorganic anions in the atmosphere of the city of Isfahan were determined. The results showed a trend of SO4(2-) > NO3- > Cl- > F-.     

Synthesis and cytotoxicity of novel chromenone derivatives bearing 4-nitrophenoxy phenyl acryloyl moiety

This work describes synthesis of novel chromenone derivatives bearing 4-nitrophenoxy phenyl acryloyl moiety through the reaction of 4-(4-nitrophenoxy)benzaldehydes and 3-acetyl-2H-chromen-2-ones in refluxing toluene. Cytotoxicity of all compounds was evaluated using a tetrazolium (MTT) colorimetric assay against human breast cancer cell line, MDA-MB-231.     

The influence of CH…π interaction on hydrogen bonding ability of –CONH<Subscript>2</Subscript> functional group of benzamide

Interplay between CH…π and hydrogen bond interactions of benzamide has been investigated by quantum mechanical calculations. The effect of the substituents on geometrical parameters has also been studied at the B3LYP level with 6-311++G(d,p) basis set. The electron-withdrawing substituents enhance the total interaction energy of the complexes. The results indicated that the cooperativity of interactions leads to extra stability of the ternary complexes. The CH…π interaction and the hydrogen bond energies have been estimated using the electron densities calculated by the atoms in molecules (AIM) method at hydrogen bond critical points. The strength of hydrogen bonding increases in the presence of CH…π interaction in the ternary complexes. The effect of CH…π interaction on the hydrogen bond interaction has also been studied by the natural bond orbital, AIM and the molecular electrostatic potential analyses.     

Experimental and kinetic study of catalytic cracking of heavy fuel oil over E-CAT/MCM-41 catalyst

The catalytic cracking of heavy fuel oil was investigated over the equilibrium fluid catalytic cracking catalyst (E-Cat) as a base component with the mesoporous MCM-41 as an additive. The catalytic performance of the E-Cat/MCM-41 system was assessed in a fixed-bed MAT unit. The reaction was performed at temperatures of 500, 530, 550 and 600°C and the product distributions in both gaseous and liquid phases were studied. The yields of products including light olefins, liquefied petroleum gas (LPG), gasoline, dry gas, coke and also the conversions obtained over different temperatures were reported and some generalities discussed. The maximum yield of propylene (17.5%) was obtained at 550°C whereas the highest conversion and gasoline yield was gained at 530°C. An eight-lump kinetic model containing 11 kinetic parameters was considered. Those parameters were estimated based on experimental data at specific temperatures by fourth order Runge–Kutta algorithm and the least square method. In addition, Arrhenius equation was used to calculate apparent activation energies. The calculated data of the product yields were in a close agreement with the experimental data.     

Thermodynamic study of complexation reactions between 1,7,10,16 Tetra oxa 4,13 diaza cyclo octa decane (Kryptofix22) and Ni<Superscript>2+</Superscript>, Cd<Superscript>2+</Superscript> and Ag<Superscript>+</Superscript> metal cations in some pure and binary mixed non-aqueous solvents using conductometry

The complexation reactions between Ni²⁺, Cd²⁺ and Ag⁺ metal cations with the macrocyclic ligand Kryptofix22 (K22), in pure acetonitrile (AN), ethylacetate (EtOAc), methanol (MeOH) and their binary mixtures have been studied at different temperatures using conductometric method. The obtained results show that in most solvent systems, the stoichiometry of the complexes formed between the macrocyclic ligand and the metal cations is 1: 1 [ML], but in some of the solvent systems, a 1: 2 [ML₂] complex and also [M₂L], [M₂L₂] and [M₂L₃] complexes are formed in solutions. The stability constans of the 1: 1 complexes were obtained using a computer program GENPLOT. A non-liner behavior was observed for changes of logK_f of the 1: 1 complexes versus the composition of AN–EtOAc binary solutions. The stability order of the 1: 1 complexes at 25°C in the binary solvent solution of AN–EtOAc (mol % AN = 50) was found to be: (K22.Ag)⁺ > (K22.Ni)²⁺ > (K22.Cd)²⁺. The obtained values of thermodynamic quantities (ΔH_c⁰,ΔS_c⁰) show that in most of the AN–EtOAc binary solvent solutions, the 1:1 complexation reactions are enthropy stabilized, but from the enthalpy view point, depending on the nature and composition of mixed solvents they are exothermic or athermic.     

Derivations on the Module Extension Banach Algebras

Ukrainian Mathematical Journal - We correct some results presented in [M. Eshaghi Gordji, F. Habibian, and A. Rejali, Int. J. Contemp. Math. Sci., 2, No. 5, 213 (2007)]. By using the obtained...