The effects of spin-orbit coupling on optical properties of monolayer [Formula: see text] due to mechanical strains.

We have studied the optical conductivity of a quasi two-dimensional [Formula: see text] in the presence of external magnetic field and spin-orbit coupling. Specially, we address the frequency dependence of optical conductivity due to spin-orbit interaction. Using linear response theory the behavior of optical conductivity has been obtained within Green's function method. We have also considered the effects of uniaxial and biaxial in-plane strain on the optical absorption of [Formula: see text] layer. In the absence of external magnetic field with negative uniaxial strain parameter, optical conductivity includes Drude weight at zero frequency limit while Drude weight vanishes for [Formula: see text] layer under positive uniaxial strain. Our results show that the increase of uniaxial positive strain parameter causes to move the position peak to the higher frequencies. In contrast to uniaxial strain case, the Drude weight in optical conductivity appears at positive biaxial strain value 0.15. Also we have studied the effects of magnetic field, electron doping, hole doping in the presence of spin-orbit coupling on frequency dependence of optical conductivity of [Formula: see text] in details. The magnetic field dependence of optical absorption shows a monotonic decreasing behavior for each value of temperature in the absence of strain parameter.

Selective removal of uranium ions from contaminated waters using modified-X nanozeolite.

In order to efficiently remove of uranium anionic species (which are the most dominant species of uranium in natural water at neutral pH) from contaminated waters, nano-NaX zeolite was synthesized and then modified using various divalent cations (Mg2+, Ca2+, Mn2+) and ZnO nanoparticles (from 1.7 to 10.3wt%). Different characterization techniques of XRF, XRD, FE-SEM, TEM, FT-IR, and AAS were used to characterize the final synthesized absorbents. Sorption experiments by batch technique were done to study the effect of solid-liquid ratio, initial uranium concentration, contact time and temperature under neutral condition of pH and presence of all anions and cations which are available in the waters. Results showed that although nano-NaX zeolite due to its negative framework charge had a low sorption capacity for adsorption of uranium anionic species, but modification of parent nano-NaX zeolite with ZnO nanoparticles and various cations effectively improved its uranium adsorption capacity. Also, results showed that under optimum condition of pH=7.56, contact time of 60min at 27°C with solid-liquid ratio of 20g/L a maximum uranium removal efficiency of 99.7% can be obtained in the presence of all anions and cations which are available in the drinking waters by NaX/ZnO nanocomposite.

Antidepressant activities of Feijoa sellowiana fruit.

OBJECTIVE: Many pharmacological activities have been reported for Feijoa sellowiana. The aim of present study was to investigate antidepressant activities of its leaf and fruit extracts. MATERIALS AND METHODS: Antidepressant activities of methanolic extracts were evaluated by modified forced swimming test (FST) and tail suspension tests (TST) in male Swiss albino mice. RESULTS: Extracts showed signicant antidepressant activity in both models. They shortened remarkably the immobility period in both FST and TST and exhibited a dose dependent activity (p < 0.001). Leaf extract showed better activity than fruit extract. At 800 mg kg-1, it showed far better activity than imipramine in FST (p < 0.001). Both extracts showed significantly better activity than imipramine in increasing climbing time (p < 0.001). They showed significant activity in increasing in swimming time as compared to the control group (p < 0.001). CONCLUSIONS: Our studies indicate that Feijoa showed significant antidepressant activity. It produced dose dependent effect on both models. It seems this effect is mainly mediated by inhibition of reuptake of catecholamines. These results introduced these plants as easily accessible source of natural antidepressant.