Sen'i Gakkaishi
Online ISSN : 1884-2259
Print ISSN : 0037-9875
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Volume 65, Issue 12
Displaying 1-13 of 13 articles from this issue
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  • Discussion on School Bags Using Shoulder Strap Pressure for Reducing Body Load
    Harumi Morooka, Tomoko Kawakami, Hideo Morooka
    2009 Volume 65 Issue 12 Pages 325-331
    Published: 2009
    Released on J-STAGE: February 02, 2010
    DOIhttps://doi.org/10.2115/fiber.65.325
    JOURNAL FREE ACCESS
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    This study aims to obtain some guidelines for designing school bags that will reduce the body load. We analyzed school bag factors that affect shoulder strap pressure in terms of the shape of strap, its cramp and waist belt. Waist belts are not used usually in school bag design. However we thought that it would be useful for reducing the body load. Seven pupils were used as test subjects. The strap pressure of the shoulder part of the curved strap was lower than that of the straight strap. But the maximum pressure and standard deviation of the curved strap were larger than that of the straight strap. The curved strap was dependent on subject's body size. An important factor was the shape of the curve. The strap pressure of the pivoting cramp was lower than that of the fixed one. Therefore, it was shown that the pivoting cramp reduced the body load. The strap pressure of school bag with waist belt tended to reduce the body load. But the effectiveness of some waist belts were dependent on the subject's height. In particular, the waist belt with the soft and wide pad didn't fit some tall subjects. It was suggested that the change in the height of one's waist due to growth was the most important factor.
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  • Specific Attraction at the Carboxyl Terminus of Fatty Acid/Oxidized Aluminum Interface for the Sizing Appearance of Fiber-network Materials
    Shingo Yokota, Kana Matsuyama, Hiroki Yamamoto, Takuya Kitaoka, Hiroyu ...
    2009 Volume 65 Issue 12 Pages 332-337
    Published: 2009
    Released on J-STAGE: February 02, 2010
    DOIhttps://doi.org/10.2115/fiber.65.332
    JOURNAL FREE ACCESS
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    The attractive force acting at a carboxyl group of a fatty acid/oxidized aluminum interface was precisely determined by atomic force microscopy (AFM). The correlation of the attractive force with the sizing behavior of paper sheets sized by a fatty acid-aluminum sulfate (alum) system was investigated. The surfaces of gold-coated AFM probes were modified with alkylthiol terminating methyl or carboxyl groups through self-assembling chemisorption. Pure cellulose film and oxidized aluminum plate were used as model substrates of cellulosic pulp fibers and aluminum components, respectively, in the sized paper sheet. A strong attractive force was detected at a carboxyl-terminated AFM probe/aluminum oxide interface both in air and water, while very weak interaction was found at the other pairs of probe/ substrates. In the fatty acid-alum systems, it was observed that such a combination was indispensable for good sizing appearance of not only organic pulp fiber sheet, but also inorganic glass filter. Consequently, the specific attractive interaction between carboxyl termini of acid sizing agents and oxidized aluminum components in the alum-treated fiber matrix should play a significant role in the water-repellent properties of porous fiber-network materials.
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  • Influence of Hydrothermal Treatments on the Chemical Composition of Intercellular Matrix Regions of Kenaf Fibers
    Hideaki Minami, Shigenori Nishiuchi, Junichiro Kadono, Yukio Sugimura, ...
    2009 Volume 65 Issue 12 Pages 338-343
    Published: 2009
    Released on J-STAGE: February 02, 2010
    DOIhttps://doi.org/10.2115/fiber.65.338
    JOURNAL FREE ACCESS
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    The influence of hydrothermal treatments on the chemical composition of intercellular matrix regions of kenaf fibers was investigated. The treatment using the hot stream of water vapor was more effective to dissolve hemicellulose fractions as compared with the treatments in hot pressurized water. On the contrary the dissolution of lignin fractions and calcium was fairly suppressed in the case of water vapor. These results suggest that the retting of kenaf fibers using hot water vapor will accompany the partial destruction of intercellular matrix although the treatment with hot pressurized water will bring about the complete destruction of the matrix.
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  • Evaluation of UV Protection Effect for UV-Cut Materials Using the Collagen Artificial Skin
    Tetsuya Takahashi, Keisuke Tanaka, Shunji Hattori, Shinkichi Irie, Sak ...
    2009 Volume 65 Issue 12 Pages 344-350
    Published: 2009
    Released on J-STAGE: February 02, 2010
    DOIhttps://doi.org/10.2115/fiber.65.344
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    For preventing damages on the skin by UV-rays, various UV-cut materials have been developed. In the present study, the authors made a collagen sheet (hereafter "collagen artificial skin") to imitate the human skin on an experimental basis and, after having covered this sheet with a film added with various UV-protecting agents, subjected it artificially to UV-irradiation. Under such condition, the skin protective effect of each kind of UV-cut materials against UV rays was examined, and the various methods to evaluate damages on the sheet caused by UV rays were also reviewed. First, the UV-rays were applied to the collagen artificial skin that was not covered with the film, and the extracts were obtained from the sheet after irradiation. The analysis of the extracts by electrophoresis revealed that the bands of three molecular chains such as alpha-, beta-, and gamma-chains of polypeptides were disappeared under UV-irradiation even only for 15 minutes (UV-Energy : 7.58X104 J/m2, at 310nm). When the irradiation time reached 25 hours (UVEnergy : 7.58X106 J/m2, at 310nm), hydrolysates from the collagen in the sheet started to appear, and when the irradiation time exceeded further 200 hours (UV-Energy : 6.06X107 J/m2, at 310nm), a considerable amount of hydrolysates was recognized. Also it was found that the longer the irradiation time of UV-rays, the higher the concentration of the terminal amino group in the extracts from the collagen was observed. Then, the UV-rays were irradiated to the collagen artificial skin added with various UV-scattering agents. As a result, addition of UV-scattering agents to the film of any of the materials reduced scission of the collagen molecular chains caused by UV-rays, resulting in reduction of the increase of the terminal amino group concentration. From the above results, it was suggested that the use of a collagen artificial skin was one of the effective measures as a method for examining the protective effect against UV-rays.
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  • Protection Effect for Collagen Artificial Skin of UV-cut Materials in Antarctica
    Tetsuya Takahashi, Tatsuyuki Yamamoto, Wakako Kasai, Tetsuo Kondo, Kei ...
    2009 Volume 65 Issue 12 Pages 351-358
    Published: 2009
    Released on J-STAGE: February 02, 2010
    DOIhttps://doi.org/10.2115/fiber.65.351
    JOURNAL FREE ACCESS
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    In the Antarctica during mid-summer being appropriate for a severe environment of UV-rays, the authors surveyed the protective effect of UV-cut materials against UV-rays, using a collagen sheet (hereafter "collagen artificial skin") that was covered with a UV-cut film and subjected to exposure outdoors. First, exposure of the laminated, collagen artificial skin not covered with any film to UV-rays caused the extracts from the 1st layer, i.e. the utmost outerlayer, of the collagen artificial skin to increase the terminal amino group concentration up to as high as 3.20 nmol/ml, since the collagen molecular chain was largely cut. On the other hand, for the 2nd and 3rd layers of the said sheet, the terminal amino group concentrations were found to have decreased in order, and for the 4th layer and onward, the concentrations were shown to have decreased down to 0.22 nmol/ml, which were nearly equal to the level before the exposure. Although the bands of three molecular chains of alpha-, beta-, and gamma-chains in all samples after exposure to UV-rays were disappeared, it was also shown that the more a layer was inside, the less the collagen molecular chain was not dissolved. In addition, when the collagen artificial skin covered with a UV-blocking, zinc oxide-added film was exposed to the sunlight, it was demonstrated that the more the addition of zinc oxide in the film increased, the lower the terminal amino group concentration in the extracts from the exposed, collagen artificial skin was observed. At the time when the added quantity of zinc oxide reached 0.40v%, the concentration was maintained almost at the same level as observed prior to the exposure. Also in comparison with UV-protecting agents, it was shown that the film added with an organic compound acting as a UV-absorbing agent reduced most the damages sustained by UV-rays. As described above, the evaluation method using a collagen artificial skin could be effectively employed in outdoor exposure for examining the protective effect of UV-cut materials to the skin against the UV-rays in the Antarctica.
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