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The effects of mechanical alloying on the microstructure of binary and ternary powder mixtures with stoichiometric compositions of Mg₂Ni and Mg₂Ni_0.75Nb_0.25 were studied, respectively. Also, the electrode properties of the milled products were investigated in 6M KOH solution. X-ray diffraction and scanning electron microscopy of the milled products showed the formation of Mg₂Ni-based nanocrystallites after 15 and 10h of milling using the initial binary and ternary mixtures, respectively. It was found that partial substitution of Nb for Ni has beneficial effect on the formation kinetic of nanocrystalline Mg₂Ni. Longer milling times resulted in the formation of an amorphous phase. A relatively high discharge capacity of 350mAhg^-1 was measured for the electrode made up of the ternary milled product after 20h. Also, the ternary milled product showed longer discharge life. This ternary electrode showed a microstructure consisting of Mg₂Ni nanocrystallites and an amorphous phase. Nb substitution for Ni was found to be beneficial to electrode properties of the milled products.

Excitonic effects are observed in the optical absorption and photoluminescence of strongly confined CdS quantum dots embedded in the polymer matrix. CdS nanoparticles of different crystallite sizes have been prepared by chemical route with polymer as a host material. The CdS nanocomposite film was made up of particle smaller than 5 nm and shows a composite band gap up to 3.2 eV, whereas the band gap for bulk hexagonal CdS is about 2.42 eV. Photoluminescence spectra show a strong emission band corresponding to electron–hole recombination and a weak band due to defect emission. The decrease of particle size was monitored from the U-V visible absorption measurement as well as photoluminescence, which suffered blue shift with decrease in particle size. The particle size and surface morphology were also analyzed by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM).

Polyvinyl alcohol (PVA) has been used as a matrix to synthesize ZnS/PVA nanocomposite film on glass substrate by chemical method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Scanning electron microscopy (SEM) has been used for structural, morphological and compositional characterization. Optical properties have been studied by UV-Visible spectrophotometry and photoluminescence (PL) spectroscopy. Changing pH value from 4.8 to 0.8 decreases the particle size and correspondingly increases the band gap. The PL emission intensity also increases by decreasing the pH values.

To study the formation mechanism of magnesium ammonium phosphate (MAP) stones. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and nanoparticle size analyzer were used to investigate the nanocrystallites in urines of 10 MAP stone patients and 10 healthy persons. Most of the nanocrystallites in healthy urines were uric acid, calcium oxalate dihydrate (COD), β-Ca₃(PO₄)₂ and NH₄MgPO₄. However, there were mainly MAP·6H₂O, calcium oxalate monohydrate (COM), hydroxylapatite, β-Ca₃(PO₄)₂ in the urine of MAP stone patients. The sizes of nanocrystallites were ranged from 22-68 nm in healthy urines and 17-92 nm in lithogenic samples. The stability of nanocrystalline in healthy urines was better than that in lithogenic samples. The nanocrystallites in MAP stone patients have a large size variation and a poor stability, easily aggregated to each other and contained more COM crystals which having a strong adhesion ability to cell membrane. All these factors promote the formation of kidney stones.