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Nakada M.,Kanazawa Institute of Technology | Miyano Y.,Kanazawa Institute of Technology | Cai H.,Xian Jiaotong University | Kasamori M.,Industrial Research Institute of Ishikawa
Mechanics of Time-Dependent Materials | Year: 2011

This paper deals with the prediction of long-term viscoelastic behavior of amorphous resin at a temperature below the glass transition temperature T g from measuring the short-term viscoelastic behavior at elevated temperatures based on the time-temperature superposition principle (TTSP) with vertical shift as well as horizontal shift. The long-term creep compliance as well as short-term and medium-term creep compliances were measured at elevated temperatures. The master curves of creep compliance can be constructed from measured data by shifting vertically as well as horizontally. The master curves of creep compliance constructed from measured data by short-term and medium-term creep tests agree well with those measured by long-term creep tests. Furthermore, the horizontal and vertical shift factors obtained from constructing the master curve are independent of the time period of creep tests. Therefore, the long-term viscoelastic behavior at a temperature below T g can be predicted accurately from measuring the short-term viscoelastic behavior at elevated temperatures based on the TTSP with vertical shift as well as horizontal shift. © 2011 Springer Science+Business Media, B. V.

Takano M.,Industrial Research Institute of Ishikawa | Takimoto M.,Nikko Company | Nakamura K.,Tokyo Institute of Technology
Acoustical Science and Technology | Year: 2011

To improve the controllability of ultrasonic linear motors in the longitudinal-bending mode, we have developed a multilayered transducer with independent electrode sets for the first longitudinal mode and the second bending mode. Since the vibration components are controlled independently by the transducer, it is possible to change only the driving vibration component with the component for friction control kept constant. The optimal shape and area of the electrodes in terms of efficiency were investigated analytically and experimentally. It was confirmed that an electrode shape in accordance with the mode strain contour gave a large output and that an optimum electrode area existed. The transducer with an optimal electrode pattern exhibited an efficiency improvement of approximately 10% and a 30% reduction of the temperature rise during motor operation. © 2011 The Acoustical Society of Japan.

Arite T.,Ishikawa Prefectural University | Arite T.,Industrial Research Institute of Ishikawa | Kameoka H.,University of Tokyo | Kyozuka J.,University of Tokyo
Journal of Plant Growth Regulation | Year: 2012

Strigolactones are recently identified plant hormones that inhibit shoot branching. Pleiotropic defects in strigolactone-deficient or -insensitive mutants indicate that strigolactones control various aspects of plant growth and development. However, our understanding of the hormonal function of strigolactones in plants is very limited. In this study we demonstrate that rice dwarf mutants that are strigolactone-deficient or -insensitive exhibit a short crown root phenotype. Exogenous application of GR24, a synthetic strigolactone analog, complemented the crown root defect in strigolactone-deficient mutants but not in strigolactone-insensitive mutants. These observations imply that strigolactones positively regulate the length of crown roots. Histological observations revealed that the meristematic zone is shorter in dwarf mutants than in wild type, suggesting that strigolactones may exert their effect on roots via the control of cell division. We also show that crown roots of wild type, but not dwarf mutants, become longer under phosphate starvation. © 2011 Springer Science+Business Media, LLC.

Sato Y.,Osaka University | Tsukamoto M.,Osaka University | Yamashita Y.,Industrial Research Institute of Ishikawa
Applied Physics B: Lasers and Optics | Year: 2015

A plate made of Ti–6Al–4V (Ti64) was built by vacuum selective laser melting (SLM) at a pressure of 10−2 Pa. The vacuum SLM system employed a single-mode fiber laser and three-axis galvanic mirror in order to form 3D metallic structure. In order to investigate the surface morphology on the fabricated plates, Vickers microhardness and surface roughness Ra were measured. From the results, the Vickers microhardness of the fabricated plates was recorded at 391 HV, higher than the typical 340 HV for a Ti64 plate. It was also determined that crystal orientation was evaluated with X-ray diffraction. From the results, the crystal orientation of powder is composed mainly of martensitic alpha. Diffraction peaks corresponding to β (110) were detected in vacuum SLM processed samples. © 2015 Springer-Verlag Berlin Heidelberg

Takano M.,Industrial Research Institute of Ishikawa
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2011

To increase the applicability of ultrasonic linear motors, we have developed a holding mechanism for the transducer using parallel leaf springs. The present mechanism is compact since the parallel leaf spring structure has functions for both holding and preloading at the same time. Also, a special design for the spring characteristics provides a non-linear load-displacement region with buckling phenomena. These results in a constant preload for some range of the displacement, then the motor performance does not alter even after abrasion of contact surfaces. In this report, the relationship between the dimension of the leaf spring and the force-displacement curves was investigated in order to obtain the design appropriate for constant preloading. Moreover, the effect of the vibration reduction by the holding mechanism was investigated theoretically and experimentally. The vibration reduction was as small as less than 10 % since the stiffness in terms of the vibration direction was relatively small. Finally, the dynamic responses of the motor with the holding mechanism were measured for a sinusoidal control signal. No prominent peak was observed in the motor's responses, however, the motor velocity change was distorted near the natural frequency of the holding mechanism. © 2011 The Japan Society of Mechanical Engineers.

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