Tapered optical fibers are promising one-dimensional
nanophotonic waveguides that can provide efficient coupling between their
fundamental mode and quantum nanoemitters placed inside them. Here,
we present numerical studies on the coupling of single nitrogen-vacancy
(NV) centers (single point dipoles) in nanodiamonds with tapered fibers.
Our results lead to two important conclusions: (1) A maximum coupling
efficiency of 53.4% can be realized for the two fiber ends when the NV
bare dipole is located at the center of the tapered fiber. (2) NV centers
even in 100-nm-sized nanodiamonds where bulk-like optical properties
were reported show a coupling efficiency of 22% at the taper surface,
with the coupling efficiency monotonically decreasing as the nanodiamond
size increases. These results will be helpful in guiding the development
of hybrid quantum devices for applications in quantum information science.

Thin films of As46Te46S8 with different thicknesses were prepared via thermal evaporation
onto chemically cleaned glass substrates at different temperatures. X-ray diffraction of the
deposited film at room temperature revealed the formation of an amorphous structure. In
addition, the selected-area electron diffraction (SAED) patterns confirmed the amorphous
phase. The mechanism of the optical absorption was observed to follow the rule of direct
transition. An increase in the optical gap (E0) from 2.35 to 2.73 eV was observed when the
substrate temperature TS was varied from room temperature to 463 K (film thickness = 100
nm). In addition, E0 was observed to be dependent on the film thickness and increased
from 1.7 to 2.38 eV when the film thickness was increased from 35 to 135 nm (TS = room
temperature). The effect of TS on the electrical properties was also studied. The electrical
resistivity (ρ) and the activation energy for conduction ( E ) decreased from 7.74 x105 to
6.81 x 102 Ω cm and from 0.55 to 0.15 eV, respectively, when TS increased from room
temperature to 448 K (film thickness = 100 nm). The Mott and Davis model for the
density of states in amorphous solids was used to interpret and discuss the results.

Thin films of As46Te46S8 with different thicknesses were prepared via thermal evaporation
onto chemically cleaned glass substrates at different temperatures. X-ray diffraction of the
deposited film at room temperature revealed the formation of an amorphous structure. In
addition, the selected-area electron diffraction (SAED) patterns confirmed the amorphous
phase. The mechanism of the optical absorption was observed to follow the rule of direct
transition. An increase in the optical gap (E0) from 2.35 to 2.73 eV was observed when the
substrate temperature TS was varied from room temperature to 463 K (film thickness = 100
nm). In addition, E0 was observed to be dependent on the film thickness and increased
from 1.7 to 2.38 eV when the film thickness was increased from 35 to 135 nm (TS = room
temperature). The effect of TS on the electrical properties was also studied. The electrical
resistivity (ρ) and the activation energy for conduction ( E ) decreased from 7.74 x105 to
6.81 x 102 Ω cm and from 0.55 to 0.15 eV, respectively, when TS increased from room
temperature to 448 K (film thickness = 100 nm). The Mott and Davis model for the
density of states in amorphous solids was used to interpret and discuss the results.

Previous studies have examined the effects of gamma-radiation on Japanese fish, in particular medaka(Oryzias latipes). In the present work, alterations in erythrocytes were recorded as haematological bio-indicators of exposure to gamma-radiation. After exposure of medaka fish to two different doses ofradiation (2 Gy and 10 Gy), many malformations in red blood cells were observed in the irradiatedfish compared with control fish. These malformations included acanthocytes, crenated cells, amoeboidcells, and sickle cells. More malformations were seen at the higher radiation dose. No micronuclei wereseen in any group, but nuclear abnormalities were observed. We conclude that gamma-radiation causesmorphological malformations of erythrocytes and is harmful to medaka fish.

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Adsorptive stripping voltammetry of antibiotics of rifamycin SV (RSV) and rifampicin (RIF) was investigated by cyclic
voltammetry and differential pulse voltammetry using a renewable pencil graphite electrode (PGE). The nature of the
oxidation process of RSV and RIF taking place at the PGE was characterized. The results show that the determination
of highly sensitive oxidation peak current is the basis of a simple, accurate and rapid method for quantification of RSV
and RIF in bulk forms, pharmaceutical formulations and biological fluids by differential pulse adsorptive stripping
voltammetry (DPASV). Factors influencing the trace measurement of RSV and RIF at PGE are assessed. The limits of
detection for the determination of RSV and RIF in bulk forms are 6.0 × 10–8 mol/L and 1.3 × 10–8 mol/L, respectively.
Moreover, the proposed procedure was successfully applied to assay both RSV and RIF in pharmaceutical formulations
and in biological fluids. The capability of the proposed procedure for simultaneous assay of antibiotics RSV-isoniazid
and RIF-isoniazid was achieved. The statistical analysis and calibration curve data for trace determination of RSV and
RIF are reported.

Sulfated zirconia catalysts were prepared by wetness impregnation of zirconium hydroxide with an aqueous solution of (NH4)2SO4 with SO42− loadings (1–30%, w/w) and calcined at 450 °C for 3 h in a static air atmosphere. The catalysts were characterized by FT-IR, XRD, TEM and BET measurements. The surface acidity of the catalysts was investigated by the dehydration of isopropanol and the adsorption of pyridine (PY) and 2,6-dimethyl pyridine (DMPY). The catalysts were tested for dehydration of methanol in a fixed-bed reactor at 230 °C using air as a carrier gas. The results revealed that among different catalysts, 10% SO42− supported onto zirconia showed the highest catalytic activity with 83% conversion and 100% selectivity toward dimethyl ether. A good correlation was found between the acidity of the catalysts and their ability to dehydrate methanol.