Takai-Yamashita C.,Nagoya Institute of Technology |
Ishino T.,Nagoya Institute of Technology |
Fuji M.,Nagoya Institute of Technology |
Inoue K.,Mie Prefecture Industrial Research Institute
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2016
A ZnO supported hollow SiO2 (ZnO/h-SiO2) composite nanoparticle with a strong yellow emission has been prepared using the Zn(OAc)2 precursor with a catalytic amount of NaOH. A single nano-sized ZnO having defective oxygen homogeneously dispersed on the SiO2 shell. How this desired structure was achieved is discussed by comparison of three carrier nanoparticles of h-SiO2, calcite core-SiO2 shell (CS), and dense SiO2 (d-SiO2) which have several spaces where the precursor solution was trapped. That is, h-SiO2 has a micropore/hollow interior/interspace among the particles, CS has a micropore/interspace, and d-SiO2 only has an interspace. On the CS carrier, similar ZnO single nanoparticles were dispersed and the ZnO/CS composite showed a strong yellow emission. On the d-SiO2 carrier, aggregated ZnO nanoparticles were localized on part of the SiO2 surface. Consequently, the existence of micropores is the key structure to obtain the ZnO nanoparticle dispersion. During penetration of the ZnO precursor into the hollow interior through the micropores, dissociated Zn2+ ions adsorb on the SiO2 surface. Hydroxide ions (OH-) of NaOH then make contact with the adsorbed Zn2+ on the SiO2 shell to form ZnO. The micropore could work as a mold to prevent excess growth of the ZnO. The strong emission was also contributed by defects among the siloxane bonds in the SiO2 shell due to its light scattering ability. The obtained ZnO/h-SiO2 can be useful as a yellow phosphor of a white light emitting diode (LED). © 2015 Elsevier B.V.
Matsuoka T.,Mie Prefecture Industrial Research Institute |
Kanai H.,Shinshu University
Journal of Textile Engineering | Year: 2015
Sitting comfort of leather car seat, whose grain leather pattern were different, were evaluated by the sensory evaluation. Physical properties and body pressure distributions of leather car seat were also measured. The adjectives used for sensory evaluation were examined by principle component analysis. From the results of subjective measurements, samples with larger unevenness of the grain were evaluated as not high-quality, not relaxed and not comfortable. Samples with smaller unevenness of the grain and smooth were evaluated as simple, familiar and comfortable. From the use of principal component analysis, two principal components were obtained, therefore, the sitting comfort were evaluated by “high-class” and “familiar”. From the correlations between sensory evaluations and physical properties or body pressure distributions, the sitting comfort of leather car seat have correlations with the physical properties, which are friction properties of surface, and with the contact pressure of the mannequin and the car seat. From the correlations of tactile sensations and sitting images adjectives, the sitting comfort for leather car seat could not be predicted by the tactile sensations of leather car seat covers. There were greatly difference between the evaluation of sitting comfort for the fabric car seat and those for the leather car seat. © 2015 The Textile Machinery Society of Japan.
Phoo-Ngernkham T.,Rajamangala University of Technology at Tawan-ok |
Maegawa A.,Mie Prefecture Industrial Research Institute |
Mishima N.,Mie University |
Hatanaka S.,Mie University |
Chindaprasirt P.,Khon Kaen University
Construction and Building Materials | Year: 2015
This article investigated the effects of sodium hydroxide and sodium silicate solutions on the properties of fly ash (FA)-granulated blast furnace slag (GBFS) geopolymer. Three types of geopolymer pastes viz., FA paste, FA + GGBS paste and GGBS paste were tested. They were activated with three types of alkaline solutions viz., sodium hydroxide solution (NH), sodium silicate solution (NS), and sodium hydroxide plus sodium silicate solution (NHNS). NH with 10 molar concentration, alkaline liquid/binder ratio of 0.60 and curing at ambient temperature of 23 °C were used for all mixes. The results indicated that the reaction products and strengths of geopolymer depended on the types of source materials and alkali activators. The use of NH and NHNS solutions resulted in the formation of crystalline calcium silicate hydrate (CSH) which co-existed with amorphous gel. Whereas the use of NS solution resulted in mainly the amorphous products with only a small amount of crystalline CSH in GBFS paste. The increase in GBFS content enhanced the compressive strength and microstructure of geopolymer pastes due to the formation of additional CSH. The shear bond strength between Portland cement concrete substrate and geopolymer paste was found to relate to both compressive strength and amount of NASH gel of geopolymer paste. © 2015 Published by Elsevier Ltd.
Matsuoka T.,Mie Prefecture Industrial Research Institute |
Kanai H.,Shinshu University |
Andou R.,Shinshu University |
Wakako L.,Kanazawa University
Journal of Textile Engineering | Year: 2014
The tactile sensations of leather car seat covers with different grain patterns were evaluated by physical touch. The covers' physical properties were also measured. The tactile sensations were evaluated using adjectives like "high-class" and"smoothness" which were examinedusing principal component analysis. From the correlations between physical properties andsensory evaluations, it was foundthat tactile sensations correlate with the physical properties of compression andsurface friction. The tactile sensations of leather covers were influencedby the grain leather pattern, and those sensations could be predicted by the physical properties. These results will contribute to a final seat design. © 2013 The Textile Machinery Society of Japan.
Wada N.,Japan National Institute of Materials Science |
Fujita K.,Japan National Institute of Materials Science |
Inoue K.,Mie Prefecture Industrial Research Institute |
Kojima K.,Ritsumeikan University
Surface and Coatings Technology | Year: 2015
To prepare transparent 90GeO2-10BaO-0.1MnO glass-ceramics for Mn4+ red fluorescence, a glass was prepared by a melt-quenching method, and then the glass was crystallized at 700 and 800°C for various seconds. The crystallization processes were investigated by measuring and observing the glass-ceramics using an XRD analyzer, an IR absorption spectrophotometer, a field emission scanning electron microscope, and a fluorescence spectrometer. As a result, for the heat treatment at 700°C, α-GeO2 and BaGe4O9 crystals doped with Mn4+ ions were formed with oxidation of Mn2+ ions to Mn4+ ones in the surface layer by heterogeneous nucleation. For the heat treatment at 800°C, by homogeneous crystallization with nano-sized phase separation, α-GeO2 and Mn4+:BaGe4O9 nanocrystals were formed in a GeO2-rich phase and an Mn4+ ions-containing BaO-rich phase, respectively. In this study, transparent 90GeO2-10BaO-0.1MnO glass-ceramics crystallized at 800°C for 102.0s by homogeneous crystallization with nano-sized phase separation, showed the strongest red fluorescence band due to the 2E(2G)→4A2(4F) transition of Mn4+ ions in the BaGe4O9 nanocrystals. © 2015 Elsevier B.V.