Nara Prefectural Institute of Industrial Technology

Nara-shi, Japan

Nara Prefectural Institute of Industrial Technology

Nara-shi, Japan

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Kimura H.,Osaka Institute of Technology | Morishima M.,Gifu City Womens College | Nishioka T.,Shinshu University | Wakako L.,Nara Prefectural Institute of Industrial Technology | Matsumoto Y.-I.,Shinshu University
Journal of Textile Engineering | Year: 2010

Many yarns are made from chemical fibers with various kinds of functional properties, and filament yarn surpasses spun yarn in terms of mechanical properties. However, in this century, "comfort", "safety", "user-friendly" and "green" are key concepts. The Food and Agriculture Organization of the United Nations (FAO) officially launched the International Year of Natural Fibers (IYNF) 2009 to celebrate the virtues of cotton, flax, sisal and hemp, and also those of wool, alpaca, camel hair and angora. In order to make effective use of natural fibers and reduce carbon dioxide emission, it is worthwhile to design and develop new spun yarns from vegetable fibers. It is also known that, in comparison with ring spun yarn, open-end spun yarn is inferior in quality. So, to produce open-end rotor spun yarn with novel functional properties, we investigated how to give it greater extension (and / or stretch), as in synthetic filament yarn. Thus, 100% cotton hollow yarns were produced using a hybrid open-end rotor spinning frame and an experimental covering machine, and the resulting mechanical properties were assessed. © 2009 The Textile Machinery Society of Japan.


Wada T.,National Institute of Technology, Nara College | Nakanishi J.,National Institute of Technology, Nara College | Miki Y.,Nara Prefectural Institute of Industrial Technology | Asano M.,Nara Prefectural Institute of Industrial Technology | And 2 more authors.
Advanced Materials Research | Year: 2012

Aluminum alloys are used for mechanical parts, but the alloys have poor wear-resistance. To increase their wear resistance, a hard coating is applied to the surface of the alloys. Diamond-like carbon (DLC) is applied in surface modification technology due to its superior mechanical characteristics. In this study, in order to achieve effective surface modification to improve the wear resistance of the aluminum alloys, a new coatings-system was designed. This coating-substrate system is a multilayer coating-substrate system, which consists of nitriding pretreatment of the substrate, the intermediate layer of the silicon-based film and the outer layer of the DLC film. This new coating-system was used to deposit DLC film on three kinds of aluminum alloys that have different Si contents. In order to determine the influence of the Si contents on the mechanical properties of the DLC film, SEM observation of the cross section of the coating layer, the adhesion and the wear resistance of the layer were experimentally investigated. The results were as follows: (1) In the case of the DLC un-coated aluminum alloys, the rapid progress of the friction coefficient in the case of 10-N load was found at the short sliding distance. (2) The hardness of the DLC film was not decreased with the increase of Si contents. And the increase of Si contents did not have a negative influence upon the hardness of the DLC film. (3) The frictional coefficient of the Al-4%Si alloy was the smallest, the frictional coefficient of the DLC film was decreased with the increase of Si contents, and it was effective for improvement of the frictional coefficient to increase Si contents. The new coating-substrate system is effective for improving the adhesion between the substrate of the aluminum alloy and the DLC film. Moreover, the increase of Si contents was effective for the decrease in the frictional coefficient. © (2012) Trans Tech Publications.


Wada T.,National Institute of Technology, Nara College | Nakanishi J.,National Institute of Technology, Nara College | Miki Y.,Nara Prefectural Institute of Industrial Technology | Asano M.,Nara Prefectural Institute of Industrial Technology | And 2 more authors.
Advanced Science Letters | Year: 2013

In order to establish effective surface modification to improve the wear resistance of aluminum alloys, a new coating system was designed. This substrate-coating system is a multi-layer substrate-coating system consisting of nitriding pretreatment of the substrate, an intermediate layer of silicon-based film, and an outer layer of DLC film. In this study, three substrate coatings, which have different thicknesses of Si-based layer and DLC film, were deposited on 6061 aluminum alloy. In order to determine the influence of the substrate-coating system on the performance of surface modification, the micro-hardness, scratch resistance, friction coefficient, wear resistance, and abrasion resistance of the coating layer were experimentally investigated. The main results obtained are as follows: (1) The DLC film hardness of each test piece was about 19 GPa and there was little difference in the DLC film hardness. (2) In the scratch resistance and adhesion test using a scratch tester, the load that caused the first cracking on the surface increased with the increase in DLC film thickness. And the load that caused catastrophic failure became larger by inserting an Si-based layer. (3) The frictional coefficient of test piece no. 3, which had an Si-based layer thickness of 0.6 μm and a DLC film thickness of 6.4 μm, was the smallest and was almost constant among the three test pieces at a sliding distance of 120 km. (4) In spite of the long sliding distance, both the width and the depth of track wear of test piece no. 3 were very small. (5) In the wear resistance test using a SUGA abrasion tester at a sliding load of 9.8 N and 19.6 N and a sliding number of 400 double strokes, no remarkable wear of test piece no. 3 was found on the sliding surface from the surface profile. © 2013 American Scientific Publishers. All rights reserved.


Islam M.R.,Japan Solartech Bangladesh Ltd | Fukugauchi M.,Nara Prefectural Institute of Industrial Technology | Morii N.,Hirano Techseed Co. | Uegaito H.,U TEC Corporation | And 2 more authors.
Proceedings of 2nd International Conference on the Developments in Renewable Energy Technology, ICDRET 2012 | Year: 2012

Oxytitanium phthalocyanine (TiOPc) and zinc oxide (ZnO) pigments working as photoactive layers have been used to fabricate pigment particle hetero-junction structured solar cells. Performance test with this double layer cell shows an energy conversion around 0.15%. On the other hand, triple layered solar cell where TiOPc is sandwiched between H 2Pc (metal-free phthalocyanine) and ZnO shows an efficiency of about 2.4%. In both cases, good life test results have been obtained. Dependences of photovoltaic characteristics on the structure of double and triple layered devices, comprised of semiconductor pigment particles are shown and their potential for future application has been discussed. © 2012 ICDRET.


Tanaka K.,Kyoto University | Adachi S.,Kyoto University | Adachi S.,Nara Prefectural Institute of Industrial Technology | Chujo Y.,Kyoto University
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2010

To investigate the relationship between the chemical structures of the side chains of polyoctahedral oligomeric silsesquioxanes (POSS) fillers and the ability to decrease the refractive indices of the polymer composites, we examined the influence on the degree of polymer chain packing by the existence of the octa-substituted POSS derivatives. The polymer composites containing methyl-, ethyl-, vinyl-, isobutyl-, octyl-, octadecyl-, cyclopentyl-, and phenyl-substituted POSS in poly(methyl methacrylate) (PMMA) were prepared. The packing coefficients of the PMMA composites containing POSS derivatives were evaluated from molar refractions and refractive indices of the films with the Lorentz-Lorenz equation. We found that the ethyl group shows the lowest values of the packing coefficients and a significant effect in reducing the refractive indices of the polymer composites. Finally, in summary, it was shown that POSS molecules can intrinsically offer to reduce a packing. In addition, less entanglement and smaller interactions between polymer chains and the substitution groups are favorable to release a packing, resulting in decreases in refractive indices. Our findings described here are the first efforts to quantitatively evaluate the ability of POSS fillers to lower refractive indices at the molecular level. © 2010 Wiley Periodicals, Inc.

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