Two novel potentiometric Morphine sensors were designed, optimized and used for the determination of this alkaloid drug. The electrodes were based on the symmetric and asymmetric designs for the application of PVC membrane sensors. Both the symmetric membrane and the asymmetric wire coated electrodes were worked based on morphine-tetraphenyl borate ion-pair complexes which act as the sensing material and they responded based on ion exchange mechanism. The optimal response behavior was at 5% wt. of the ion-pair, 30% wt. of PVC and 65% wt. of DBP for the symmetric devices and at 25% wt. of PVC, 5% wt. of the ion-pair morphine-tetraphenyl borate, 2% wt. of ionic additive and 68% DBP. The PVC membrane sensor was found to have a Nernstian behavior in the concentration range of 5. 0×10-5-1. 0×10-2 mol L-1, while the wire coated electrodes showed linear behaviors from 1. 0×10-7 to 1. 0×10-4 mol L-1. Both devices proved to satisfactorily applicable in the analysis of Morphine hydrochloride in pharmaceutical formulation under laboratory conditions.

Asymmetrically mixed matrix Matrimid-MIL-53 membranes with silicone cover layer were fabricated. For better understanding of membrane fabrication process, three main parameters of fabrication, Matrimid concentration, silicone concentration and weight percentage of metal organic framework (MIL-53) particles, were optimized by an experimental design method. Cross-section SEM images were used to study the membrane structure and polymer-particles interface. Moreover, thermal resistance of the membranes and the existence of various bonds in them were investigated by FTIR and TGA analyses. The results showed that membranes had porous structure with finger-like morphology. At low and moderate percentages of particles, there were no non-selective voids observed at polymer-particles interface.The thermal resistance of membranes increased with the increase of MIL-53 weight percentage and the destruction temperature of polymer increased from 410°C to 450°C.The permeability tests results showed that the Matrimid (20% wt) -MIL-53 (15% wt) / PMHS (10%wt) membrane exhibited the highest level of CO2/CH4 selectivity (23.6).However, in the membrane with 30 wt% particles loading, selectivity decreased due to particles agglomeration and void formation. The experimental design results showed that the concentration of silicone in covering solution had significant effect. CO2 and CH4 permeability decreased and ideal selectivity of CO2/CH4 increased with silicone concentration enhancement. Although the Matrimid concentration had a little effect on CO2/CH4 ideal selectivity, its enhancement increased the selectivity of the gases.The optimization results showed the membrane with 17.8% of Matrimd polymer, 13.2% of silicone polymer and 15.5 wt% of MIL-53 particle displayed the highest selectivity and CO2 permeability.

The refining industry is one of the most important industries in the Tehran Stock Exchange, and it has a significant impact on the behavior of the existing shares in it due to fluctuations in global oil prices. These effects are in such a way that they also affect the relationship between each share and the others. Therefore, in order to address the impossibility of examining all the shares available in the stock market, the formation of an optimal portfolio of various industries requires the identification of leading shares in this industry. To this end, in this study, using daily data in the period from August 30, 2016, to May 21, 2023, and employing the Asymmetric TVP-VAR method, the relationship between refining industry shares in three states of positive returns, negative returns, and general returns has been examined. The results of this study indicate that there is an asymmetrical relationship between negative and positive returns, with a stronger relationship observed in positive returns. Additionally, Shabna, Shabriz in negative returns, and Shebandar in positive returns are the leading shares in the refining industry.

In this study, effect of asymmetric functionalized graphene oxide (Janus GO) on Young′ s modulus and glass transition temperature of Polysulfone (PSf) ultrafiltration membranes was investigated. The membranes were prepared via phase inversion method and GO nanosheets were dispersed in casting solution by sonication. Results showed that the Normalized Young’ s modulus (on the basis of neat PSf membrane Young’ s modulus) increased from 1 to 1. 35 for neat PSf membrane compared to the membrane with 1% Janus GO nanosheets. This enhancement indicated the improvement of mechanical properties of modified membranes. Also, application of Janus GO nanosheets caused enhancement of thermal stability of modified membranes by increasing glass transition temperature to 182. 97 ° C compared to 180. 1 ° C for neat PSf membrane. These improvements were ascribed to the enhancement of dispersion and stability of Janus GO nanosheets in membranes matrix.