New spectrofluorimetric method for the determination of nizatidine in bulk form and in pharmaceutical preparations

Optics and Spectroscopy - A simple, accurate and highly sensitive spectrofluorimetric method has been developed for determination of nizatidine in pure form and in pharmaceutical dosage forms. The...     

Sandwiched trilayer of Bethe lattices in the form of spin-(1/2,1,1/2)

The sandwiched trilayer of Bethe lattices in the form of the spins with spin-(1/2,1,1/2) Ising model is studied in terms of the recursion relations with either ferromagnetic or antiferromagnetic type bilinear interactions between the nearest-neighbor (NN) spins. The ground-state (GS) phase diagrams are obtained and it was found that the model presents six different GS phase configurations. In order to obtain the phase diagrams, the thermal variations of the order-parameter, spin-spin correlation functions and free energy are analyzed and different topological phase diagrams are obtained. It was found that the system exhibits different critical behaviors such as, second- and first-order phase transitions, tricritical and bicritical points for the values of the coordination numbers q=3,4 and 6.     

Revalidation of the isobaric multiplet mass equation

We have determined the energy of the J(pi) = 1/2(+), T = 3/2 resonance in 32S(p,p) to be E(p) = 3374.7+/-0.8 keV. This disagrees with the previously accepted value of E(p) = 3370+/-1 keV by Abbondanno et al. [Nuovo Cimento 70A, 391 (1970)] and solves a problem raised by recent observations of unexpected deviations from the isobaric multiplet mass equation. This resonance is also important in calibrating the beta-delayed proton spectra from 33Ar and 32Ar, and our findings may modify previous conclusions.     

Nano-crystalline aluminum-containing hydroxyapatite based bioceramics: synthesis and characterization

The hydroxyapatite and hydroxyapatite-based bioceramics with high Al contents were synthesized using sol–gel method, and their characterization was carried out by X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy. With the increase of Al content, the crystallinity is dramatically decreased, and the phase structure belonging to hydroxyapatite was transformed into the new phases, including aluminum calcium phosphate and/or aluminum phosphate. The average crystallite size of the bioceramic samples was found to be in the range of 10–50 nm. FTIR spectroscopy results verified the presence of various $ {\text{PO}}_{4}^{3 - } $ and $ {\text{OH}}^{ - } $ groups in the samples. The density value of the samples significantly increased with the addition of Al. It is evaluated that hydroxyapatite bioceramic can be converted to new bioceramics with high Al contents.     

Structure and conductivity characterization of new type ionic conductor stabilized bismuth oxide ternary systems

In this study, the new type electrolyte (Yb₂O₃)_x(Dy₂O₃)_y(Bi₂O₃)_1-x-y ternary compounds were synthesized with different stoichiometric ratios by the solid-state reaction method at different annealing treatment and also their microstructural and electrical properties were analysed. X-ray powder diffraction results showed that the high temperature δ-phase of pure monoclinic Bi₂O₃ has been synthesized by doping of Yb₂O₃. Grain size and grain form of pellet formed samples was compared from their surface images taken by the scanning electron microscopy. The grain size has been varying between ～17–37 µm, and degrading with the increasing dopant concentrations. The relationships between the structural parameters (e.g. lattice parameters, crystallite size and the lattice microstrain) and structural properties (e.g. ionic radii of dopant cations and heat treatment procedure) were particularly discussed. Total conductivity values were calculated by Nyquistic complex impedance plot. Impedance measurement revelaed that total conductivity values of the samples increase with the increasing Yb dopant ratio. The activation energies calculated by the Arrhenius approach are measured at around 1?eV. In addition, activation energies and pre-exponential terms decrease with the increasing Yb cation dopant rate for the same ambient temperature.