Synthesis of Nano Silica Particles for Polishing Prepared by Sol–Gel Method

In order to produce an excellent abrasive, a fabrication method for cocoon shaped silica particles has been studied. The particles are prepared from TMOS, water, ammonia and methanol by a sol–gel method. The method is to add the methanol solution of TMOS at a constant supply rate to a mixture of water, ammonia and methanol. Effects of various reaction conditions such as temperatures, supply rates of TMOS, and amounts of TMOS are studied on the diameter and shape of the particles. The diameter and shape are resulted in depending strongly on temperatures. High temperature makes particles with the high aspect ratio and the small diameter. And the mechanism of forming the cocoon shaped particle is also discussed. It is concluded that the primary particles are generated at the beginning stage of reaction and two of them become the cocoon shaped particle. For the polishing efficiency, particles have high polishing efficiency with the diameter between 40 nm and 210 nm. As a result, best diameter of particles for abrasive is 40–100 nm with respect to polishing efficiency and surface finish.     

Reaction of 2,3-diphenylpyrazine 1-oxides with acetic anhydride

Some 2,3-diphenylpyrazine 1-oxides were heated with acetic anhydride to give the corresponding 2,3-di-acetoxy-2,3-dihydro-5,6-diphenylpyrazines. By X-ray diffraction analysis, the configuration of two acetoxyl groups was determined to be trans.     

Soluble Polymer Complexes Having AlQ3‐Type Pendent Groups

Summary: Polymethacrylate having a pendent 8‐hydroxyquinoline moiety was prepared using Kelex‐100 (7‐(4‐ethyl‐1‐methyloctyl)‐8‐hydroxyquinoline) as a starting material. A soluble polymer having tris(8‐hydroxyquinolinato)aluminum (Al Q ₃)‐type side chains was obtained through the complexation of the polymer with Me₃Al in the presence of a monomeric Kelex‐100. The polymer complex was applied to an organic light‐emitting diode (OLED) device through a spin‐cast process.

Structure of the tris(8‐hydroxyquinolinato)aluminum‐type pendent group bound to polymethacrylate giving rise to the first soluble polymer of its kind.     

Flexible Twin Open Ring Metro WDM Network

We have demonstrated a flexible twin open ring WDM network for metro applications. A pair of optical switches in the network keeps the fiber rings open to prevent signal circulation. Traffics are broadcast to every node and selected at the receiving side. Superior transmission and protection switching are proved.     

Formation of Si structure in glass with a femtosecond laser

Mixing metallic Al into the starting material for silicate glass is proposed as a means of forming Si structures in glass. We confirmed that Si nanocrystals are space-selectively deposited in silicate glass via a thermite reaction triggered by femtosecond laser pulses. Small Si particles were transformed into larger, but still micrometer sized, Si particles by laser irradiation. These structures grew to micro-size particles due to the thermite reaction promoted by heat treatment. We discuss what effect the irradiation of the focused laser pulse had on the Si deposition process in the laser-irradiated region. Localized high temperatures and pressures and generation of shock waves appear to be very important in forming Si-rich structures that contribute to the growth of Si particles. The diffusion of calcium ions by the generation of shock waves and the presence of Al-rich structures is important for forming Si-rich structures such as Si clusters, which is achieved by continuously breaking Si–O bonds using localized high temperatures.     

Esaki diodes live and learn

We report, as the result of shelf-life tests for Esaki diodes, the observation of minute but tangible reductions in the tunnel current after the lapse of half a century. The reduction could be attributed to 0.25% widening in the tunnel path.     

Emission mechanism of radiophotoluminescence in Ag-doped phosphate glass

The objective of this study is to investigate the emission mechanism of radiophotoluminescence (RPL) in the Ag⁺-doped phosphate glass (glass dosimeter), which is now used as individual radiation dosimeter, because the emission mechanism of RPL in glass dosimeter was not fully understood. Optical properties such as optical absorption spectrum, RPL spectrum and change of RPL spectrum as a function of X-ray irradiation dose were measured for commercially available glass dosimeter. In this study, we discuss the emission mechanism of two RPL peaks at 460 nm and 560 nm, based on the fact that electrons and holes produced by X-ray irradiation are trapped at Ag⁺ ions to produce Ag⁰ and Ag²⁺ ions, respectively, when the Ag⁺-doped phosphate glass is exposed to X-ray. We would like to propose the emission mechanism of RPL peaks at 460 nm and 560 nm, concerning with Ag²⁺ and Ag⁰ ions.     

Determination of fluvoxamine in rat plasma by HPLC with pre-column derivatization and fluorescence detection using 4-fluoro-7-nitro-2,1,3-benzoxadiazole

A sensitive, simple and reliable method using high-performance liquid chromatographic (HPLC) assay of fluvoxamine (FLU), a selective serotonin reuptake inhibitor (SSRI), in rat plasma after pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was developed in this study. Extracted plasma samples were mixed with NBD-F at 60 degrees C for 5 min and injected into HPLC. Retention times of FLU and an internal standard (propafenone) derivative were 15.5 and 13.5 min, respectively. The calibration curve was linear over the range 0.015-1.5 microg/mL (r2 = 0.9985) and the lower limits of detection and quantification of FLU were 0.008 and 0.015 microg/mL, respectively, in 100 microL of plasma. The derivative sample was stable at 4 degrees C for 1 day. The coefficients of variation for intra-day and inter-day assay of FLU were less than 8.3 and 9.6%, respectively. Other SSRIs and centrally acting drugs did not interfere with the peak of the FLU derivative. The method was applied for analysis of the plasma samples from rats treated with FLU. These results indicate that the method presented is useful to determine the FLU levels in rat plasma of volumes as small as 100 microL and can be applied to pharmacokinetic studies.