Development of high luminous efficacy red-emitting phosphor-in-glass for high-power LED lighting systems using our original low Tg and Ts glass.

Red-emitting phosphor-in-glass (PiG) materials with a high luminescence efficiency were developed by co-firing commercial red-emitting (Sr,Ca)AlSiN3:Eu2+ (SCASN) phosphor and our original glass frits with a composition of Li2O-Na2O-ZnO-Al2O3-B2O3-P2O5, which has a low Tg (271°C) and Ts (380°C) temperatures. By optimizing the sintering temperature and the content of the phosphor, the highest luminous efficacy was obtained for the 3 wt.% SCASN-based PiG sintered at 400°C, which showed a luminous efficacy of 25 lm/W rad by combining the PiG materials with a blue light-emitting diode (LED) chip-on-board (COB, incident power = 100 mA). The internal quantum efficiency of this sample under excitation at 450 nm was 53%. The PiG-based LED maintained a high luminous efficacy when the incident power of the blue COB increased up to 5.5 W (47 lm).

Temperature and Vibration Dependence of the Faraday Effect of Gd2O3 NPs-Doped Alumino-Silicate Glass Optical Fiber.

All-optical fiber magnetic field sensor based on the Gd2O3 nano-particles (NPs)-doped alumino-silicate glass optical fiber was developed, and its temperature and vibration dependence on the Faraday Effect were investigated. Uniformly embedded Gd2O3 NPs were identified to form in the core of the fiber, and the measured absorption peaks of the fiber appearing at 377 nm, 443 nm, and 551 nm were attributed to the Gd2O3 NPs incorporated in the fiber core. The Faraday rotation angle (FRA) of the linearly polarized light was measured at 650 nm with the induced magnetic field by the solenoid. The Faraday rotation angle was found to increase linearly with the magnetic field, and it was about 18.16° ± 0.048° at 0.142 Tesla (T) at temperatures of 25 °C-120 °C, by which the estimated Verdet constant was 3.19 rad/(T∙m) ± 0.01 rad/(T∙m). The variation of the FRA with time at 0.142 T and 120 °C was negligibly small (-9.78 × 10-4 °/min). The variation of the FRA under the mechanical vibration with the acceleration below 10 g and the frequency above 50 Hz was within 0.5°.

Scheduled interval trans-catheter arterial chemoembolization followed by radiation therapy in patients with unresectable hepatocellular carcinoma.

Combination treatment of trans-catheter arterial chemoembolization (TACE) and conformal radiation therapy (RT) reported promising results in patients with hepatocellular carcinoma (HCC), but, optimal interval was not determined. We hypothesized that a two-week interval between TACE and RT would be optimal. Therefore, we designed this study to evaluate the safety and efficacy of scheduled interval TACE followed by RT. HCC patients who were not eligible for standard therapies were enrolled for scheduled interval TACE followed by RT (START). Patients received TACE on the first day of treatment, and then RT was delivered after 14 days. The entire course of treatment took between four and five weeks. In 81 patients (96.4%), START was completed in the planned treatment period. RT was delayed in the remaining three patients because of decreased liver function or poor performance status after TACE. Of the 81 patients, objective response was observed in 57 patients (70.4%). One unexpected death occurred after START due to hepatic failure. Other toxicities were manageable. The median survival was 14.7 months. There was a significant difference in overall survival according to the response to START (P < 0.001). In conclusion, START is safe and feasible.

The phase analysis of spark plasma sintered MgB2 after ball milling.

Mg and amorphous B powders below 10 and 3 micro meter were used as raw materials, and mixed by planetary-mill for 9 hours at argon atmosphere. MgB2 bulk was fabricated at the various temperatures by Spark Plasma Sintering. In the sintering process, mixed powders were sintered in graphite mold, at the pressure of 55 Mpa. The fabricated MgB2 samples were evaluated with XRD, EDS, FE-SEM, PPMS. MgB2, MgO and Fe phases were observed from XRD result. In the results, MgO and Fe were impurity which may affect superconducting properties of MgB2 samples, and it's distribution could be confirmed from EDS mapping result. In order to confirm the formation of MgB2 phase, DTA was used as heating rate of 10 degrees C/min at Ar atmosphere from room temperature to 1200 degrees C. In the PPMS result, the Tc (critical temperature) was about 21 K, and the density of spark plasma sintered samples increased to 1.87 g/cm3 by increasing sintering temperature.

Flow modification enhancing the growth rate in top seeded solution growth of SiC crystals.

In this study, multiphysics simulations were carried out to understand the convection mechanisms of the top seeded solution growth (TSSG) of SiC. Experimental melting tests and crystal growth were conducted to verify the simulation results in the growing temperatures between 1700 and 1900 °C with rf induction heating furnace. From the solidified melt of Si-Cr solution after the melting test, the melt flow in the simulation was successfully verified. In the given experimental conditions, the electromagnetic convection was found to govern the global fluid flow, while other mechanisms including the Marangoni convection, the buoyancy convection and the centrifugal forced convection influence the fluid flow near the crystal. Based on an understanding of the fluid flow obtained with the simulations, a structural flow modifier (FM) was applied to enhance the growth rate of the SiC crystal. The growth rates of SiC with/without FM were successfully estimated from simulations showing good agreements with the experimental values. After the experimental crystal growth using FM, a remarkable enhancement in the growth rate was found in an FM configuration, which suggests a way to improve the growth rate by the TSSG method based on the efficient use of the dissolved C in the melt.

Effect of aluminum on the formation of silver metal quantum dots in sol-gel derived alumino-silicate glass film.

The effect of aluminum incorporation on silver metal quantum dots formation in the alumino-silicate glass film processed by sol-gel process was investigated. The sol-gel derived glass was coated onto the silica glass plate by spin coating with the mixture solution of tetraethyl orthosilicate (TEOS), C2H5OH, H2O, AgNO3, Al(NO3)3. 39H2O, and HNO3 with the molar ratios of Ag/Si = 0.12 and Al/Si varying from 0 to 0.12. The formation of the silver metal quantum dots was confirmed by the measurements of the UV/VIS optical spectra, the X-ray diffraction patterns, and the transmission electron microscope images. While the radius of silver metal quantum dots increased with the increase of aluminum concentration, the concentration of the silver metal quantum dots decreased. The formation of the silver metal quantum dots was found strongly suppressed by incorporation of aluminum ions in the glass. The change in the glass structure due to the aluminum incorporation was investigated by the analysis of the Raman spectra. The silver ions in the glass contributed to form stable (Al:Ag)O4 tetrahedra by pairing with aluminum ions and thus clustering of silver metal quantum dots was hindered.

Fabrication and optical characteristics of a novel optical fiber doped with the Au nanoparticles.

Optical fibers containing gold metal nanoparticles were developed by modified chemical vapor deposition, in which Au(OH)3 and tetraethyl-orthosilicate (TEOS) was used via sol-gel process to incorporate gold metals by providing the reduction atmosphere. The absorption peak appeared near 490 nm was found to be due to the surface plasmon resonance of the gold nanoparticles incorporated in the fiber core.