Undoped and gadolinium doped nanostructured mesoporous materials, such as NiO, Ni0.98Gd0.02O, Ni0.95Gd0.05O, and Ni0.92Gd0.08O, were synthesized by a facile hydrothermal route using urea as the hydrolysis controlling agent and were studied for supercapacitor applications. The thermal stability of the synthesized samples was identified by thermogravimetric analysis. The phase structure of the as-synthesized and calcined materials was characterized by using powder X-ray diffraction. The average crystallite size of the oxide materials was found to be in the range of 8.2–11.3 nm. Fourier transform infrared spectroscopy revealed the metal–oxygen bond in the compounds. The analyzed morphological phenomenon of the prepared samples confirms the mesoporous flake-like shape. The N2 adsorption/desorption isotherms were performed to examine the surface area and pore-size distribution. The elemental composition and charge states analyses were obtained by energy-dispersive X-ray and X-ray photoelectron spectroscopy, respectively. Cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopic measurements were applied in an aqueous electrolyte to investigate the electrochemical performances of the active electrodes. Among the four electrodes, Ni0.98Gd0.02O exhibits the highest surface redox reactivity and shows optimum high specific capacitance of 1190 F/g at a current density of 2 A/g. The cycling lifespan of Ni0.98Gd0.02O with capacitance retention of 81.43% was inspected over 3000 cycles at a current density of 3 A/g.

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Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 Å resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 Å , = 109.35 . Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit.