We represent a metal complex which has been synthesized by the simple reaction with Ni(II) chloride and pyridine (as a lignd) affording a complex having the molecular formula [], characterized on the basis of elemental analyses, electronic, infrared, ¹ H NMR, ¹³ C NMR spectra, magnetic susceptibility, and also aid of molar conductivity measurement. Conductivity measurement reveals nonelectrolytic nature of the complex. IR and ¹³ C NMR spectra reveal the presence of cis ‐ and trans ‐structure. On the basis of above analyses the square planar cis ‐ and trans ‐structures are proposed for the prepared complex.

Sluggish oxygen reduction reaction (ORR) of electrodes is one of the main challenges in fuel cell systems. This study explored the kinetics of the ORR reaction mechanism, which enables us to understand clearly the electrochemical activity of the electrode. In this research, electrocatalysts were synthesized from platinum (Pt) catalyst with multi-walled carbon nanotubes (MWCNTs) coated by three polymers (polybenzimidazole (PBI), sulfonated tetrafluoroethylene (Nafion), and polytetrafluoroethylene (PTFE)) as the supporting materials by the polyol method while hexachloroplatinic acid (H₂PtCl₆) was used as a catalyst precursor. The oxygen reduction current of the synthesized electrocatalysts increased that endorsed by linear sweep voltammetry (LSV) curves while increasing the rotation rates of the disk electrode. Additionally, MWCNT-PBI-Pt was attributed to the maximum oxygen reduction current densities at −1.45 mA/cm² while the minimum oxygen reduction current densities of MWCNT-Pt were obtained at −0.96 mAcm². However, the ring current densities increased steadily from potential 0.6 V to 0.0 V due to their encounter with the hydrogen peroxide species generated by the oxygen reduction reactions. The kinetic limiting current densities (J_K) increased gradually with the applied potential from 1.0 V to 0.0 V. It recommends that the ORR consists of a single step that refers to the first-order reaction. In addition, modified MWCNT-supported Pt electrocatalysts exhibited high electrochemically active surface areas (ECSA) at 24.31 m²/g of MWCNT-PBI-Pt, 22.48 m²/g of MWCNT-Nafion-Pt, and 20.85 m²/g of MWCNT-PTFE-Pt, compared to pristine MWCNT-Pt (17.66 m²/g). Therefore, it can be concluded that the additional ionomer phase conducting the ionic species to oxygen reduction in the catalyst layer could be favorable for the ORR reaction.

Industrialization and urbanization grow up the development of any country. Chittagong, the second largest city of Bangladesh, is suffering a great deal for water pollution problem. Various types of compound contaminated with heavy metals or heavy metals compound are conventionally used in different industry. Wastage from the industries is finally discharged into different surface water body without treatment creating pollution. Our investigation was carried out to evaluate the status of heavy metal in the different canal of Chittagong City. Concentration of Cu, Mn, Zn, Pb, Ni, Co, Ag Fe, Cd, Al and Ag were determined by Atomic Absorption Spectrophotometer (AAS). In all canals Pb contents were higher than the standard limit of Environment Conservation Rules 1997. Pb concentration of Hamzerbagh canal was the highest (8.03 mg/ml) of all and second highest was Mirzapol canal i.e. 7.777 mg/l. Cr content that found to very much higher in the two canals near from Kulgoan (Tannery Bottal) area were 23.73 mg/L and 10.45 mg/L. Fe concentration of sample, collected from Muradpur canal, Hamzerbag canal and Mirzarpol canal found higher than the standard limit were 7.95, 4.94 and 4.41 respectively. High concentration of Pb, Cr and Fe were found also higher than the standard limit indicating imperiled state of canal water of Chittagong City.

ObjectiveTo explore the antidiabetic and the antidiarrhoeal effects of ethanolic extracts of Cynodon dactylon Pers. aerial parts (EECA) in Wistar rats.MethodsTo assess the antidiabetic activity of EECA, oral glucose tolerance test (OGTT) model and alloxan induced diabetic test (AIDT) model were performed. The EECA was used at the doses of 2 g/kg, 1 g/kg and 500 mg/kg body weight in OGTT model and 1.5 g/kg was used for AIDT model. Castor oil-induced diarrhoeal model and gastrointestinal motility test with barium sulphate milk model were performed for evaluating the antidiarrhoeal effects at doses of 1 g/kg, 750 mg/kg respectively.ResultsThe dose 2 g/kg in OGTT and 1.5 g/kg in AIDT model blood glucose levels decreased significantly (P < 0.01) in Wistar rats that showed antidiabetic effect of EECA. After administration of EECA at the dose of 1 g/kg, the extract showed significant (P < 0.05) antidiarrhoeal activity in castor oil-induced diarrhoeal model. The results were also significant (P < 0.05) in barium sulphate milk model for the same dose by using above mentioned animals.ConclusionsIt is concluded that EECA contains both antidiabetic and the antidiarrhoeal properties