Microstructures of InN film on 4H-SiC (0001) substrate grown by RF-MBE

InN film was grown on 4H-SiC (0001) substrate by RF plasma-assisted molecular beam epitaxy (RF-MBE). Prior to the growth of InN film, an InN buffer layer with a thickness of ~ 5.5 nm was grown on the substrate. Surface morphology, microstructure and structural quality of InN film were investigated. Micro-structural defects, such as stacking faults and anti-phase domain in InN film were carefully investigated using transmission electron microscopy (TEM). The results show that a high density of line contrasts, parallel to the growth direction (c-axis), was clearly observed in the grown InN film. Dark field TEM images recorded with diffraction vectors g = 1120 and g = 0002 revealed that such line contrasts evolved from a coalescence of the adjacent misoriented islands during the initial stage of the InN nucleation on the substrate surface. This InN nucleation also led to a generation of anti-phase domains.     

Gamma-rays shielding properties of xPbO:(100 − x)B2O3 glasses system at 662 keV

The mass attenuation coefficients, total interaction cross-sections and effective atomic numbers of xPbO:(100 − x)B₂O₃ (where 30  x  70% weight) glass system have been investigated on the basis of the mixture rule. The results are good agreement with the theoretical values, calculated by WinXCom. Mass attenuation coefficients were increased with increase PbO content, due to increase effective atomic number of glass samples, which increase probability of photoelectric absorption in glass. However, Compton scattering gives dominant contribution to the total mass attenuation coefficients for studied glass samples. Their shielding properties of glass samples are also better than ordinary shielding concretes and commercial window glass which can be used with advantage as transparent in visible region. These results are indicating the potential of glasses in radiation shielding materials.     

Improvement of optical properties of nanocrystalline Fe-doped ZnO powders through precipitation method from citrate-modified zinc nitrate solution

Nanocrystalline Zn_1−xFe_xO (where x = 0, 0.01 and 0.02) powders were successfully synthesized by a precipitation method from citrate-modified zinc nitrate solution. X-ray powder diffraction, Fourier transformed infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy were used to study the structural properties. The optical properties were determined by UV–vis spectrophotometer and luminescent spectrometer. In this study, the optical band gap of nanocrystalline ZnO powder increased from 3.170 eV to 3.214 eV when the Fe concentration in the solution was increased up to 2 mol. %.     

Designs and investigations of anti-glare blue-tint side-view car mirrors

Recent developments for luxury car industries have been in favor of anti-glare color-tint side-view exterior car mirrors. In this study, we explore the designs, the fabrications, and the investigations of anti-glare blue-tint samples suitable for the side-view car mirrors. With an aid of the thin film design software, the TiO₂-based backside-coated optical systems are prepared by the homemade and the retailed sputtering systems, and examined for the reflection spectra and the chromaticity diagrams. From four major designs of the anti-glare blue-tint mirrors, the ultra-thin metallic layer and the dielectric stack with the bottommost reflective layer offer the blue-tint at 85% highest reflection. Although the design requires only 40 min of the deposition time, the careful control of the ultra-thin metallic film thickness is crucial.     

Synergetic removal of aqueous phenol by ozone and activated carbon within three-phase fluidized-bed reactor

Synergetic removal of aqueous phenol by decomposition with ozone and adsorption on activated carbon was experimentally investigated. To enhance phenol removal performance, two activated carbons (AC1 and AC2) with BET surface areas of 1106 and 1150 m² g^?1 and average pore diameters of 2.3 and 1.7 nm, respectively, were employed. While the slowest initial removal of phenol was achieved with introduction of ozone only, the much better removal of phenol was obtained with utilization of activated carbon with ozone. Some intermediate products, which were detected as total organic carbon (TOC), were found to remain even after phenol was completely decomposed. Regarding to higher mesopore fraction, AC1 could better remove intermediates than AC2. With the synergetic performance of AC1 and ozone it was found that the highest removal of phenol and TOC was up to 100% and 89%, respectively.     

Safety and immunogenicity of REMUNE in HIV-infected Thai subjects

The safety and immunogenicity of REMUNE, an HIV-specific immune based therapy for HIV infection, was evaluated in a cohort of 30 HIV infected subjects in Thailand. This therapy utilizes a gp120 depleted inactivated virus (HZ321), which exhibits a high degree of conservation with the core antigens of both type B' and E strains of HIV, the predominant Thailand isolates. The treatment was well tolerated, with no serious adverse events reported over the course of the 4-month trial. Treatment in which four doses were administered with REMUNE appeared to boost HIV-specific immune responses, with approximately 75% of the treated subjects demonstrating an increase in either the repertoire or the intensity of the serological response to HIV as measured by Western blot. CD4%, viral load, and weight remained stable over the course of the 4-month study relative to baseline values. Viral subtyping of this cohort revealed a predominance of type 'E'. These data suggest that REMUNE is safe and immunogenic in seropositive Thai subjects and supports further study of the therapeutic potential of REMUNE to treat HIV-1 infection.     

Characterization of inhomogeneity in TiO2 thin films prepared by pulsed dc reactive magnetron sputtering

This article discusses an analytical method for characterizations of TiO₂ thin films and determinations of the degree of their inhomogeneity. The TiO₂ films were prepared by a pulsed dc magnetron sputtering with an operating pressure as a main experimental parameter. The obtained films were primarily characterized for film crystallinity, microstructures and optical properties by spectroscopic ellipsometry. The measured ellipsometric data were analyzed by the single-, the double, and the triple-layer models in order to match with the inhomogeneous film structure proposed in the Thornton structure zone model. The results were then compared with those obtained from grazing-incidence X-ray diffraction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The study revealed that the pulsed dc sputtered TiO₂ films could be best described by the inhomogeneous triple-layer physical model. Although the films deposited at lower operating pressure had a dense structure with a mirror-like surface topography, the films deposited at higher operating pressure had the porous structure with the rough surface and the void.     

Temperature effects on freshwater snail shells: Pomacea canaliculata Lamarck as investigated by XRD,EDX, SEM and FTIR techniques

In this study, the XRD, EDX, SEM and FTIR analyses are used for the characterization of the thermal decomposition process of Pomacea canaliculata Lamarck (PCL) samples. All these shells are abundant in Thailand. The shell was ground into fine powders. A set of four samples each was then separately annealed for 2 h in air atmosphere at 300°C, 400 °C, 450 °C and 500 °C, respectively. The PCL shell mainly consists of aragonite and a fraction of calcite. If the PCL powder samples were annealed at a temperature higher than 450 °C, it resulted in an irreversible phase transformation from aragonite to calcite. The FTIR spectra analyses of PCL show that, after an annealing, the relative intensities of CO₃²⁻ absorption bands and the intensities of OH⁻ absorption band increased.