When a train travels through a tunnel at high speed, large pressure variations are generated in the tunnel. It is thus essential to accurately predict these pressure variations when planning to increase the speed of Shinkansen or Maglev trains. We have developed a one-dimensional flow simulation program to calculate the pressure variations and the wind velocity in a high-speed railway tunnel. This program can perform predictions for tunnels with shafts and/or stations/terminals for train speeds up to about 500 km/h. The simulation results agree well with the results of model experiments.

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We investigated a calibration method of a parallel mechanism stage which is installed under a microscope. Our proposed method uses measurement data of the 2-DOF translations on the surface (x-y plane) of the end-effector and the rotation about the axis (z) perpendicular to the surface, and these measurement data are obtained by the measurement method with a micro grid pattern. We discuss the calibration method with simulations and experiments for a stage comprised of a fixed linear actuated parallel mechanism. The results show that the calibration which restricts measurement data to those 3-DOF of the end-effector is possible and has good performance.

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In a fatigue analysis for Class 1 components in the Rules on Design and Construction for Nuclear Power Plants (The First Part : Light Water Reactor Structural Design Standard) in the JSME Codes for Nuclear Power Generation Facilities, a simplified elastic-plastic analysis is used when the primary plus secondary stress intensity exceeds 3 times the Design Stress Intensity. The simplified elastic-plastic analysis is to multiply elastic-analysis-based stress by a Ke-factor. It is well-known that the Ke-factor of the ASME Boiler and Pressure Vessel Code Section III has a large amount of conservatism. Hence, to develop an appropriate Ke-factor evaluation method, the Ke-factor Advisory Committee was established in June 1999 as a research committee of the Thermal and Nuclear Power Energy Society. Typical basic models were selected from actual structures. Elastic analyses and elastic-perfectly plastic analyses were performed for the basic models and the Ke-factors were calculated. Ke equations were established by bounding the Ke-factors. The new Ke equation was verified by using experimental data of piping. The Ke factors for typical actual nozzles of which Ke-factors were relatively higher were directly analyzed and it was confirmed that the developed Ke evaluation method could be higher than the Ke-factor directly analyzed. Based on those evaluations, the Ke' equation expressed by Primary + Secondary Stress Intensity (S_n) and the Ke" equation expressed by Primary + Secondary + Peak Stress Intensity (S_p) were developed. The Ke' equation has been taken in the JSME Design and Construction Code and the Ke" equation has been taken in the Code Case, "Alternative Structural Evaluation Criteria for Class 1 Vessels based on Elastic-Plastic Finite Element Analysis".

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This paper presents the theoretical procedure to predict the vibratory response and radiated noise of the engine block coupled with the rotating crankshaft and gear train shafts which drives the fuel injection pump and valve system. The exciting forces acting on the engine block and shaft system are combustion pressure, inertia forces of the moving parts, piston slap forces, fuel injection pressure and valve driving force and torque. Theoretical procedures consist of the following four steps; (1) Dynamic characteristics of the engine block and shafts are determined separately by Finite Element Method or experimental modal analysis, (2) Normal mode expansion technique is employed to derive the equation of motion of the total system in which rotating shafts with gear train are combined to the engine block by the oil film and contact stiffness, (3) The time histories of the vibratory response of the engine block and rotating shafts are calculated by the numerical integration technique, (4) Engine noise radiated from the engine block surface is evaluated using the Boundary Element Method. This method is applied to estimate the effect of the backlash of the gear train on the engine block vibration and radiated noise.

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In the present paper, we derive a solution for two circular holes or rigid inclusions that are perfectly bonded to an elastic medium (matrix) of infinite extent under in-plane deformation. These two holes or rigid inclusions have different radii and different central points. The matrix is subjected to arbitrary loading, for example, by uniform stresses, as well as a concentrated force at an arbitrary point. The solution is obtained through iterations of the Möbius transformation as a series with an explicit general term involving the complex potential of the corresponding homogeneous problem. This procedure is referred to as heterogenization. Using these solutions, several numerical examples are presented graphically.

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Synchronized phenomena have been observed in various areas, such as mechanical, electrical and chemical engineering. Mutual interaction plays an important role in synchronized phenomena. In this study, we explore the possibility of quenching self-excited sounds generated from two Helmholtz resonators by mutual interaction. Two resonators are connected with tube at the bottom of each resonator. To quench a self-excited sound using another self-excited sound as interference, the frequencies of the two sounds must be identical and their phases opposite. Accordingly, in this study synchronization is performed to match the frequencies and maintain the phases. To induce synchronization, a certain type of interaction must be utilized; thus, an acoustic interaction is used. We sought in-phase and antiphase conditions experimentally and found that the phase of self-excited sounds depends on the length of the tube connecting the two resonators.

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JR-East has been working on a research and development project to increase Shinkansen operation speed to 360 km/h. Methods of wayside noise reduction arise as major issues when increasing the Shinkansen's operating speed, as it is necessary to keep wayside noise levels within those of existing Shinkansen trains, even at a speed of 360 km/h. Two high-speed test trains were developed: "FASTECH360S" (running only on Shinkansen lines) and "FASTECH360Z" (running on both Shinkansen and conventional lines converted to Shinkansen gauge). Both of the trains feature several new types of equipment for reducing pantograph noise and noise from the lower part of cars, which have the greatest impact on overall noise level in series E2-1000, operating at a maximum speed of 275 km/h. Running tests were conducted with the FASTECH360 trains to measure wayside noise at a point 25 meters from the center of the track and 1.2 meters above the ground. The results show that to operate at the same noise levels as trains in service (series E2 and E3 (coupled) running at 275 km/h), FASTECH360S and FASTECH360Z (coupled) would have to run at approximately 330 km/h, and FASTECH360S (solo) at approximately 340 km/h. Although the goal of 360 km/h is yet to be attained, it was confirmed that the countermeasures incorporated in the FASTECH360 trains greatly reduced wayside noise. These measures are used for the new generation Shinkansen trains, "Series E5" which have been in operation on the Tohoku Shinkansen line since March 2011.

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In this study, a new riveting method considering design for disassembly is developed. The method can join sheets by high-speed blanking without drilling them as well as easily disjoin the joined sheets. The joining is carried out as follows: 1) A pair of a rivet with a rivet head and a rivet holder that has already been drilled at the center as the other rivet head is set so that their center axes may agree and two sheets are interposed between them. 2) The rivet shaft set on the upper sheet is struck into sheets by the collision of a weight at high speed and the rivet shaft penetrates the sheets. 3) The rivet shaft penetrating the sheets enters into the hole of the rivet holder and then the tip of the rivet shaft projecting from the hole collides with a die. Then the shaft and the rivet holder are joined because the plastic deformation of the shaft generated by the collision fills up the hole of the rivet holder and the sheets are fastened tightly by both the rivet with the rivet head and the rivet holder. The experimental results showed that the strength of a joint made by the impulsive riveting method was higher than that of a joint made by caulking, and that the deformation of sheets was small. In addition, the joined sheets could be disjoined easily.

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Heat pumps are becoming a more common means to reducing CO₂. Heat pumps are typically used for residential and commercial building air-conditioning and will likely expand to industrial uses in the future. For example, in food and beverage sector, the operating temperature of factories is relatively low, which means that the introduction of heat pumps is relatively easy. This analysis provides estimates of the CO₂ and primary energy reduction potential of heat pumps in the food and beverage sector in 18 countries. For electric drive compressor heat pumps, where heat demand below 100°C has been selected as applicable. This report concludes that CO₂ emissions can be reduced by 49 million tons per year. This amounts to about 1.4% of CO₂ emissions from fuel combustion in the industrial sector in the countries surveyed. Primary energy amount of 13 million toe per year (including fossil fuels of 17 million toe per year) can be reduced by replacing boilers with heat pumps in the food and beverage sector of the countries surveyed.

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To improve the applicability of the side branch silencer, the acoustic characteristics of the side branch with a finite impedance at the end was obtained by the experiment. As a result, it was clarified that the peak frequency of the noise reduction (NR) could be decided from the side branch length and the natural frequency of the end of a side branch. Moreover, the experimental result is in good agreement with the analysis of FEM considering the theoretical impedance of the circular membrane and the theoretical calculation by the transfer matrix method. In addition, it has been understood that the peak frequency of NR in this side branch corresponds to the natural frequency of a simple tube of the one open end and the other end with an impedance. Additionally, it was understood that the calculation of the natural frequency of the simple tube is effective for the prediction of the frequency at which NR becomes maximum.

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In the present study, degradation properties of the polymer blends of Poly(lactic acid) (PLA) and Poly(butylene succinate) (PBSU) with different mixed fractions were investigated. PLA/PBSU(50/50) exhibited the highest water absorption during hydrolysis tests because water absorption was accelerated due to the existence of interface between PLA and PBSU, crystal and amorphous. Tensile tests were performed on the polymer blends after 0, 8 16 and 24 weeks hydrolysis tests to evaluate the variation in tensile strength and Young's modulus. Tensile strength of PLA/PBSU (100/0, 80/20, 50/50 and 20/80) were sensitive to hydrolytic degradation. The variation in molecular weight and existence of induction time for decreasing strength indicated that massive degradation occurred during hydrolysis tests. Analysis based on the auto-catalysis effect of end carboxyl group can fit the molecular weight variation for pure PLA and PBSU.

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A new system is proposed in order to prevent over-rotation of a small horizontal axis wind turbine in a strong-wind condition. The system consists of a mandrel bar and a fiber-reinforced rubber pipe in which the metal fiber is arranged with oblique angle. This is installed at the root of each blade respectively. When the rubber pipe is subjected to the centrifugal force due to the rotation of the blade, the fibers are forced to be straight in the loading direction. This yields the torsional deformation of the pipe, and achieves the change of the pitch-angle of the blade corresponding to the revolution of the turbine passively. The tensile tests are performed to examine the fundamental elastic behavior of the fiber-reinforced rubber pipe. To investigate the performance of the electric power generation by the wind turbine with the present system, the wind tunnel tests are carried out. It is confirmed that the present system enables to avoid the over-rotation of wind turbine and realizes the stable power generation even in the strong-wind condition.

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