Near Infrared Absorption of Tungsten Oxide Nanoparticle Dispersions

Homogeneous dispersions of reduced tungsten oxide and tungsten bronze nanoparticles with ternary additives Na, Tl, Rb, and Cs have been prepared in the wet process and examined for optical properties. The dispersions of reduced tungsten oxide and tungsten bronze nanoparticles are found to show a remarkable absorption of near infrared light while retaining a high transmittance of visible light. This property is highly suitable for solar control filters in automotive and architectural windows.     

A visualization study on relationship between water-droplet behavior and cell voltage appeared in straight, parallel and serpentine channel pattern cells

It is a critical issue to understand the relationship between water-droplet behavior and cell voltage for the establishment of PEFC water management. We fabricated three cells, whose channel pattern is different: straight one channel, parallel three channels and serpentine one channel. We operated these different channel-pattern cells and visualized water droplets in cathode channel, with systematically changing operation condition to quantitatively compare the performance and water droplet behavior between the cells. Successive process of water behavior, named as flooding, plugging and flushing, emerged in every channel-pattern cell. However, the each channel pattern cell also has inherent water behavior, showing particular cell voltage variation. Within our experimental condition, the serpentine one channel cell showed a superior tolerance to flooding and the highest performance among the three cells.     

An approach to the automation of the assembly of flexible belt-shaped objects

A robot system was developed for the assembly of flexible belt-shaped objects, and the assembly procedures employed by workers in using it were analysed. A multi-fingered hand was developed to hold the objects at several points, and to move them into the proper position for attachment to a part. In addition, an image processing method that can recognize the gripping positions on source objects and conditions after the source objects are attached is proposed.     

STABILITY OF STRONTIUM(II) AND BARIOM(II) COMPLEXES WITH 18-CROWN-6 IN AQUEOUS SOLUTION AND THEIR EXTRACTABILITY AS PICRATES

When strontium(II) and barium(II) were extracted with 18-crown-6(l 8C6) and picrate ions into chloroform, log(distribution ratio of metal(II)) approached flat in a higher region of log[18C6], although it is reported that the distribution ratio of copper(II) or zinc(II) increases in proportion to the second order of 118C6]. From the extraction data analysis, the flat distribution ratio was explained by the formation of the aqueous complex with 18C6 and the stability constants for strontium(II) and barium(II) were determined to be 2.89 and 3.68 as logβ1respectively.     

Sol-Gel Preparation of Transparent and Conductive Aluminum-Doped Zinc Oxide Films with Highly Preferential Crystal Orientation

Transparent aluminum-doped zinc oxide (ZnO) films were prepared via the sol-gel method on silica-glass substrates from 2-methoxyethanol solutions of zinc acetate and aluminum chloride that contained monoethanolamine. Dip coating was conducted at room temperature, with substrate withdrawal rates of 1.2-7.0 cm/min. After each deposition, the films were heat-treated in air at 200°-450°C for 10 min (pre-heat-treatment). After six to fourteen layers had been deposited, the films were then subjected to annealing in air at 500°-800°C for 1 h (the first post-heat-treatment), followed by annealing in nitrogen at 500°-700°C for 15 min to 4 h (the second post-heat-treatment). All the films obtained were transparent and showed only an extremely sharp ZnO (002) peak in the X-ray diffractometry (XRD) patterns. The effects of the aluminum content, the substrate withdrawal speed, and the heat-treatment conditions on the electrical resistivity of the films were studied. All these factors strongly affected the resistivity. The lowest resistivity value (6.5 10^-3 Omegacm) was achieved in a film that contained 0.5 at.% aluminum, prepared with a low substrate withdrawal speed (1.2 cm/min), and a pre-heat-treatment of individual layer at 400°C in air and a post-heat-treatment of the entire film at 600°C in air, followed by a post-heat-treatment at 600°C in nitrogen. These preparation parameters also affected the degree of crystal orientation, which was revealed by the intensity of the ZnO (002) XRD peak. Higher crystal orientation was effective in reducing the film resistivity, whereas the higher grain-packing density and possible aluminum segregation were thought to have positive and negative effects, respectively, in reducing the resistivity.     

Improvement of a Real Gas-Sensor for the Origin of Methane Selectivity Degradation by µ-XAFS Investigation

Nano-Micro Letters - We have directly investigated the chemical state of the Pd species in a real μ-gas sensor device by examining the μ-fluorescence X-ray absorption fine structure. The...     

Thermoplastic softening behavior of organically modified polyoxotitanates: Effects of the amount of water and benzoylacetone for hydrolyzing alkoxides

Organically modified polyoxotitanates were prepared by hydrolyzing titanium tetra‐n‐butoxide in the presence of benzoylacetone (BzAc) in solution at Ti(OC₄H₉)₄ : BzAc : H₂O : CH₃COCH₃ mole ratios of 1 : (1 or 2) : (1 or 10) : 20. The solutions were concentrated at 80°C and dried at 140°C in N₂ flow, producing transparent and yellow materials of BzAc‐modified polyoxotitanate. The materials had refractive indices of ～1.7 and exhibited thermoplastic softening at temperatures below 70°C. Low contents of BzAc and high contents of H₂O in solution led to higher softening temperatures of the materials, indicating the tunability of the softening temperature. Gel permeation chromatographic analyses showed that the higher softening temperatures originated mainly from polymerized species of higher molecular weights that were generated by hydrolysis and condensation reactions promoted by the low BzAc and high H₂O contents in solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42653.     

High-intensity laser-driven particle and electromagnetic wave sources for science, industry, and medicine

We simultaneously observed both the fast proton generation and terahertz (THz) radiation in the laser pulse interaction with a thin-foil target.The maximum proton energy of ～2.3 MeV and an intense THz radiation were observed at the pulse duration of ～30fs.We also measured the proton beam and UV harmonics from a thin-foil target by changing the laser pulse duration.In the case of the ～500 fs, peaks of UV harmonics up to fourth order appeared.This unique combination of the multiple beams will provide useful applications such as pump-probe experiments.