In this study, a highly-reliable evaluation method of the strength of a grain in polycrystalline copper thin films was developed to establish a relationship between the crystallinity and the effective strength of a grain and a grain boundary by combining EBSD (Electron Backscattered Diffraction) analysis and micro tensile test system. The crystallinity of a grain or a grain boundary was quantitatively expressed as IQ (Image Quality) value obtained from the EBSD analysis. And the strength of a grain in polycrystalline copper thin films was evaluated by using the developed micro tensile test. Finally, the obtained results indicated that the critical resolved shear stress of this microstructure significantly changed with the IQ value of the grain boundary.

Electroplated gold thin films have been used for micro bumps in flip chip packing structures. However, it has been reported that physical properties and micro texture of the electroplated gold thin films fluctuate drastically depending on their manufacturing process. In particular, it was found that the long-time reliability of micro bumps and interconnections is degraded drastically by porous grain boundaries due to a lot of defects because of the acceleration of atomic diffusion along the porous grain boundaries under the application of high current density (electromigration) and high mechanical stress (stress-induced migration). In this study, in order to evaluate the effect of atomic arrangement of under layer on the crystallinity of electroplated gold thin films, under layer material used for electroplating was changed; such as Cr (30 nm) /Pt (50 nm) /Au (200 nm) and Ti (30 nm) /Au (100 nm). The micro texture of the films such as crystallinity and crystallographic orientation was analyzed by EBSD (Electron Back-Scatter Diffraction) and XRD (X-Ray Diffraction). It was found that the crystallinity of both grain and grain boundaries of the electroplated gold varied depending on the quality of atomic arrangement of under layer and heat treatment. Therefore, it is significantly important to control of the crystallinity of under layer in order to control of physical properties and reliability of the electroplated gold thin films.

A modified 9Cr-1Mo steel is a ferritic heat resistant steel expected to be used for piping materials for FBR (Fast Breeder Reactor). According to the S-N curve obtained at elevated temperatures during high-cycle fatigue test on this steel, the existence of the fatigue limit was not confirmed in the number of cycles up to 1×108 cycles in the test at 500℃ or higher. Furthermore, the lath martensitic texture, which is the reinforced structure of this steel, was confirmed to disappear during the high-temperature tests. The reason why the fatigue limit did not appear can be attributed to the degradation of the strength due to this change of micro texture, the disappearance of the initially dispersed lath martensitic texture, during the fatigue tests at elevated temperatures. In this research, we attempted to elucidate the degradation of the strength of a grain of this alloy accompanying the microstructural change, to guarantee the lifetime and strength reliability of the modified 9Cr-1Mo steel. The microstructure change was observed by the EBSD (Electron Back Scatter Diffraction) method and SIM (Scanning Ion Microscope), and the change of the strength of a grain during the creep test was measured by a micro tensile test method. As a result, the tensile strength and the yield stress of the single crystal grain decreased as the average KAM (Kernel Average Misorientation) value of a grain decreased. By using these methods, it was possible to clarify the degradation process of this alloy from the viewpoint of the change of its micro texture.

The energy demand in Hokkaido fluctuates greatly due to heat load. Therefore, we can‘t increase the amount of renewable energy introduced by wind power generation and solar power generation. Therefore, in this research, we studied a system that adjusts the fluctuation of energy demand in Hokkaido with hydrogen fuel derived from renewable energy. We used a genetic algorithm that can handle many variables with nonlinear characteristics at the same time in the analysis algorithm. As a result, we found that electric power using conventional oil generator can be reduced to about 55% of demand. In addition, it was found that the equipment utilization rate of the hydrogen production machine can be secured to 80% or more.

In Japan, the restart of nuclear power generation and the introduction of renewable energy are expected to proceed in the future. Therefore, we focus on smart houses with storage batteries and aim at load leveling of the electric grid from the viewpoint of improving facility utilization rate of thermal power generation. In the previous study, we investigated the operation method of storage batteries by numerical analysis using genetic algorithm (GA) and the purpose is power load leveling on one detached house for one day. Based on the results of this survey, we proposed an operation plan for storage batteries that minimizes the day gap of electricity demand, but its effectiveness has not been clarified. Therefore, in this paper, we perform operation test of demonstration system based on operation plan of storage battery made by GA and investigate load leveling rate and the increase in facility utilization rate. In addition, the operation plan is created from using solar radiation forecast information updated every hour, and the system is operated while correcting the plan. Therefore, we investigate the reduction effect of electricity charges by the revised plan. As a result of the demonstration test on the representative days of January, April and July, the load leveling rate of each month was 61.1%, 82.3%, 54.5%. Increase in facility utilization rate in each month was 15.0%, 9.7%, 4.9%. In addition, calculating the electricity unit price after the load level, the electricity unit price can be reduced by about 4.0 yen / kWh.

A building integrated energy system (photovoltaic (PV) and fuel cell (FC) is proposed for assessment of the energy-sufficiency rate in seven cities (Nagoya, Toyota, Tajimi, Takayama, Ogaki, Hamamatsu, Shizuoka) in Tokai region. In this work, it is considered that the electricity requirement of the building for household user is provided by the building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H₂ produced from the surplus power of PV. A design study of using the proposed system in seven cities has been performed. It has been observed that the monthly power production from BIPV as well as FC system is higher than in spring and summer, while it is lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that the 16 households are more suitable. Since the climate condition is more favorable, Hamamatsu is the best city for installing the proposed system among considered cities. The relationship between the households’ number and self-sufficiency rate of the FC system per solar PV installation can be expressed by the approximate curve of y = ax^b well.

This research aims to develop a power generation system that utilizes the dissociation and expansion characteristics of CO₂ hydrate. The only energy required for the proposed power generation system is heat and electricity is generated using the pressure difference generated during the production and dissociation of CO₂ hydrate. In this paper, in order to improve the dissociation efficiency of CO₂ hydrate, dissociation experiment of CO₂ hydrate was attempted three times. In the first experiment, CO₂ hydrate dissociation experiment was conducted by changing the thermal conductivity of the reaction vessel. As a result, it was confirmed that by increasing the thermal conductivity of the reaction vessel, the dissociation efficiency of CO₂ hydrate is improved. In the second experiment, dissociation experiments of CO₂ hydrate with different set pressures of the reaction vessel were carried out. As a result, very high dissociation efficiency of CO₂ hydrate was obtained under high pressure environment. In the third experiment, CO₂ hydrate dissociation experiment using iron oxide catalyst was conducted. As a result, it was confirmed that the dissociation efficiency of the carbon dioxide hydrate was improved by adding the iron oxide catalyst. In the previous experiments, the dissociation efficiency of the highest CO₂ hydrate was 42.5%. From the above results, it was found that the dissociation efficiency of CO₂ hydrate can be improved by a reaction vessel with high thermal conductivity and added with an iron oxide catalyst in a high pressure environment.

Gas hydrate has gas molecules in cage-like water molecules, large pressure difference by the change of state is obtained to a small temperature change. This study propose a power generation system that utilizes unique state change characteristics by thermal cycle of gas hydrate. The required energy for operation of the proposed system is only heat, and the heat source use the waste heat (high temperature heat source) of individual houses and the outside air temperature (low temperature heat source) in the cold district. We developed a trial power generation system which adopts scroll expander for actuator. It uses CO₂ in consideration of safety and convenience. CO₂ hydrate is generated from the contact part between water and CO₂ gas. Therefore, investigate the change in overall efficiency by changing the installation method (contact area) of the reactor in the trial power generation system. As a result, it is expected that the power generation efficiency will reach 11.8% by properly installing the reactor.

Mid-infrared absorption spectroscopy was used for measuring the mixing ratio of bio-fuels in practical fuels. In this study, a measurement device for ethyl tert-butyl ether (ETBE) concentration using an 8.93 μm quantum cascade laser has been developed. We measured the absorption spectra of gasoline surrogate/ETBE mixtures with varying the ETBE mixing ratio, and created a calibration curve to determine the concentration of ETBE at 1117.0 cm^-1. We performed measurements of the ETBE concentration in practical gasoline using the developed system. The obtained data is in good agreement with the data measured using gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectrophotometer (FTIR), which are traditional measurement systems for fuel components.

In order to improve the thermal efficiency of spark ignition (SI) engine, it is necessary to develop an ultra-lean burn technology in combination with EGR (exhaust gas recirculation). Addition of hydrogen to gasoline fueled engine is effective for extending the lean limit. In this study, the effect of addition of hydrogen on the engine performance of a gasoline fueled lean burn SI engine with EGR was investigated using a single cylinder research engine. As a result of heat balance analysis, the cooling loss and the exhaust loss decrease with expanding the lean limit by adding hydrogen, while the combustion efficiency decreases due to the increase in unburned fuel loss. The thermal efficiency can be improved by hydrogen addition on the basis of the balance of the losses.

DI Gasoline engine tends to increase the particulate mass concentration in the case of cold start, warming-up process and high load condition. In this study, PM emission was investigated from cold start to warming-up stage. The engine coolant temperature is set to 8°C, 30°C and 80°C, and start of fuel injection is changed from -320 deg.ATDC and -90 deg.ATDC. The excess air ratio, the load (gross indicated mean effective pressure, Gross IMEP) and the combustion phase (CA 50) was adjusted to 1.0 and 0.7 MPa, ≈ 9 deg. ATDC, respectively. The fuel injection pressure was kept constant at 10 MPa. As a result, when the coolant temperature was changed to 8°C, 30°C and 80°C, it was found that the soot at the coolant temperature of 8°C increased. In addition, it was found that soot was less affected by coolant temperature from -300 deg. ATDC to -120 deg. ATDC. Soot tends to increase at the injection condition -320 deg. ATDC and -90 deg. ATDC where the piston top surface is approaching the injector. The soot increased because fuel adhered to the piston top surface and pool combustion occurred. Also at -90 deg.ATDC, soot formation from the rich region due to mixing failure is considered to be an influencing factor.

This paper reports the effect of flow field on the deformation of spark discharge channels in terms of understanding of the spark ignition in the flow field. The automotive spark plug was installed in the constant-area flow (usually 25mm in diameter) with the orifice in the downstream to control the flow rate. The high pressure mixure gas was introduced through electro-magnetic valves from the upstream of the spark plug. The high voltages were applied using ignition coils and the deformation of the discharge channels in flow field were observed with high-speed camera. Due to the flow field, the spark discharge deformed in the flow direction. The total discharge time decreased with the increase in the flow velocity because of the high voltages due to the elongation of the discharge channel. The tip of discharge channel moved with time linearly and movement velocity of the channel were estimated. The movement velocity increased with the increase in the pressure and the trackability of the channel to the flow field was estimated.

Laminar flame speed plays an important role in turbulent combustion models used in engine combustion simulation. A laminar flame speed of gasoline surrogate fuel and isooctane / air mixture under high pressure condition simulating the inside of an engine cylinder was obtained by double kernel method using laser excitation plasma. Pressure dependence of laminar flame speed was investigated.

Homogeneous charge compression ignition (HCCI) combustion system is promising as a new combustion system reducing NOx and PM simultaneously without any penalty of fuel consumption. However, the operational range of the HCCI combustion is limited because of some issues to be solved such as poor control of ignition timing and the excessive rate of pressure rise. In this study, a new combustion system based on the HCCI combustion process has been proposed. The combustion system has a divided combustion chamber into two parts, one is small and the other is large. On the combustion process, burned gas ejected into the large chamber induce ignition of the mixture in the large chamber and then the combustion process in the large chamber is aimed to go on same manner of the HCCI combustion process. This paper presents influences of engine specifications and experimental conditions on engine performance and combustion characteristics.

A mathematical model of the mechanical loss in a turbocharger is needed to accurately evaluate the efficiency of turbochargers. In our previous study, a mechanical loss model was constructed. Then, the sensitivity analysis by the model could reproduce the trend of friction loss. Particularly, as the temperature of the oil film decreased, the value of the friction rapidly increased. In this study, the constructed model was validated by the experiments using a retardation method. Comparison between the model and the experiment shows that the change trend of the experimental values with each parameter was consistent with the values obtained by the model qualitatively but not quantitatively. Then, the parameters of the model such as the eccentricity ratio of the shaft and the floating bushes, the rotating speed ratio of the floating bushes against the shaft, and the temperature of the oil film were regulated, and the difference between the model and the experiment is improved.

The piston rings, the engine sliding parts, are required to further contribute on mechanical loss reduction in order to improve fuel economy. However, many cases of the abnormal combustion due to the oil upward flow, as well as the increase in oil consumption are been reported. It is widely known that the cylinder bore shape during the actual operation, and the distribution of the sliding surface pressure in between the piston ring and the cylinder bore largely influence the oil flow via the sliding surface of the piston ring. Accordingly, verification of the sliding surface pressure during the actual operation is necessary in order to elucidate the mechanism of oil consumption. The thin film sensor is widely used as a measurement method of the sliding surface pressure between two different faces, however this method has never been applied to the piston ring in the past. For application of thin film sensing technique, Authors, through the examination of film deposition methods, succeeded in forming the thin film sensor with a total thickness of 4-5 micron by the sputtering method on the sliding surface of the piston ring. In addition, by improvement of the each device of the measurement system, the noise reduction of the measurement system was developed and the signal noise ratio could be greatly improved. Furthermore, it was confirmed that the thin film pressure sensor, was developed in this study, is able to perform as a sensor for measurement of the piston ring sliding surface pressure.

Supercritical DME spray in an optically accessible constant volume vessel under four ambient conditions was observed by a high-speed camera. Parallel light shadow graph and diffused light shadow graph method were applied to image the liquid and vapor phase behavior separately. The spray angle of supercritical spray was compared with that of subcritical one under the same ambient condition to confirm the influence of the difference in fuel temperature. The results show that the spray angle of supercritical spray was bigger than that of subcritical one under relatively low pressure ambient conditions. This can be explained by p - v diagram. However, under high pressure ambient condition like turbo charged engine, there is no difference in spray angle between supercritical and subcritical. The reasons are as follows: (a) the difference in specific volume between liquid and vapor is small at ambient pressure near critical pressure; (b) high ambient temperature has a greater influence on spray angle than fuel temperature because the heat transfer from the ambient increases with increase in temperature difference between fuel and ambient.

Effect of Injection pressure on combustion of diesel spray under high temperature and high pressure ambient was experimentally examined using a constant volume combustion chamber of 60cc that simulated the combustion chamber of automobile diesel engine. The heat release rate was calculated from combustion pressure using a pressure gauge. The KL factor was quantified through an image analysis technique using two-color method. The value of injection pressure was changed from 160MPa to 80MPa. By comparing the heat release rate, the total KL factor and the two dimensional KL factor distribution, the effects of injection pressure on combustion and soot formation was discussed. The experiments were conducted in two series, i.e., the constant injection duration condition and the constant injected fuel mass condition. It was explored that the longer injection duration under low injection pressure enhance the deterioration of soot oxidation at the overlapped region of adjacent spray flame.

The aim of this study is to clarify the effect of the overlap with multi-injected diesel sprays on soot formation. The present study investigated the effect of the interval between a pilot and a main injection on soot formation in a main spray flame using a constant volume combustion vessel based on 2D laser induced incandescence (LII) method. Obtained results show that if a main spray is injected into a burnt gas region of a pilot flame, the soot density in the shear region of main spray is increased on a relatively early stage of combustion.

Two-stage combustion was generated by two-stage fuel-injection with a single cylinder diesel engine. The sound source locations were identified for one of the main noise frequencies by using a sound source visualization device for different second fuel-injection timings, -10 deg. ATDC and -6 deg. ATDC, when the two-combustion impacts are amplified and cancelled at 2500 Hz, respectively. The results show that there were a few sound sources and the sound pressure level near each sound source increased first, attained maximum and decreased over time. The maximum sound pressure level for each sound source for the second stage fuel-injection start timing of -10 deg. ATDC was greater than that for the second stage fuel-injection start timing of -6 deg. ATDC. The decay rate was greatest for the sound source with the maximum sound pressure level in the present engine.

A calculation code for simulating spray combustion in the marine Diesel engine of uniflow scavenging was created, taking formation / extinction of NOx and soot and a skeletal reaction scheme into consideration. The influence of multistage fuel injection on the emission of NOx and soot from a supercharged marine Diesel engine of uniflow scavenging was examined by this calculation code. As the results of calculations carried out changing the amount and timing of pilot- and after-injection, it was found that NOx decreased by pilot-injection. On the other hand, after- injection from the same fuel injector was not able to decrease soot. So after-injection from the dedicated fuel injector was performed on a trial basis, and it was confirmed that the reduction of soot exhaust could be realized.

Next generation bio-alcohols produced from non-food based sources are promising renewable energy sources. The present study investigates engine performance, combustion characteristics, and emissions of a small single cylinder DI diesel engine fueled by two kinds of next generation bio-alcohol isomer and diesel fuel blends with constant blending ratio of 3:7 (mass). The tested bio-alcohol isomers here are iso-butanol (C₄) and iso-pentanol (C₅). The experiments employed supercharging combined with EGR in the tested engine equipped with a jerk type injection system. The EGR rates were varied from 0 to 25% using a cooled EGR technique. The boost pressures were fixed at two conditions, 100 kPa (N/A: naturally aspirated condition) and 120 kPa (S/C: supercharged operation) provided with a roots blower type supercharger. The result showed that both with and without supercharging, bio-alcohol isomers (iso-butanol and iso-pentanol) blended fuels improved the trade-off relation between NOx and smoke emissions at all EGR rates while maintaining good engine performance, when compared with standard diesel fuel operation.

In order to use bio-isopentanol as a raw material for biodiesel production, coconut oil isopentyl ester (CiPE) was made from coconut oil and isopentanol by transesterification. As a result, the pour point of CiPE is -12.5 °C and it is the same as that of coconut oil isobutyl ester (CiBE). The combustion characteristics and exhaust emissions of CiPE were investigated using a DI diesel engine, and were compared with that of CiBE and JIS No.2 diesel fuel (gas oil). The thermal efficiency of CiPE is almost the same as that of the other test fuels. Although the HC and CO emissions of CiPE are higher than that of CiBE, these are almost the same as that of gas oil. CiPE has lower smoke emission compared to gas oil. It is concluded that CiPE is a good alternative diesel fuel.

Fuel reforming catalysts installed in the EGR system of gasoline engines are used to form hydrogen with steam reforming. However, deteriorations of the catalyst due to sulfur poisoning and carbon deposition are concerned for the practical use. In the present study, five catalysts consisting of different materials were examined to explore the catalysts that increase the hydrogen production and the tolerance. The experiments on variations of sulfur contents contained in the reformed fuels revealed that lanthanum (La) has a strong resistance to carbon deposition and adding platinum (Pt) or palladium (Pd) results in a high resistance to the sulfur poisoning.

To investigate the hydrothermal aging behavior of urea SCR (selective catalytic reduction) catalysts coated on DPF, NOx conversion was obtained using hydrothermally aged Cu-ZSM5-type SCR catalyst with different Si/Al ratio. NOx conversion decreased with increasing Si/Al ratio using fresh catalyst, which was considered to be caused by the difference in Cu amounts in the catalyst. Further, NOx conversion decreased with increasing aging time, regardless of Si/Al ratio. On the other hand, it was found that the decreasing tendencies were different for different Si/Al ratios in the catalyst, which indicated that the aging mechanism was affected not only by the Cu amount but also by the aging behavior of Al in the zeolite.

A high-precision NOx reduction model of urea SCR (selective catalytic reduction catalyst) applicable to the design of aftertreatment devices for diesel engines is required. For constructing the model, it is necessary to investigate the reaction mechanism for estimating the amount of ammonia (NH₃) generated from urea. In order to evaluate the reaction mechanism of NH₃ formation from urea, reactions related to isocyanic acid (HNCO), which is an intermediate species formed during the decomposition of urea to form NH₃, were studied. The rate constants of the reactions of HNCO hydrolysis and HNCO with NO, which is one of the side reactions, were obtained using a flow reactor. Furthermore, we investigated the influence of the reaction of HNCO with NO on NH₃ formation during the simultaneous occurrence of HNCO hydrolysis in the presence of H₂O.

In this study, characteristics of the induction period of n-heptane/air ignition process, which is a term between low temperature oxidation (LTO) and high temperature oxidation (HTO), were investigated based on chemical kinetics analysis. Fuels having different reactivity, methane, propane, isobutane and n-butane, were used as a secondary fuel, and they were added to n-heptane/air mixture. It was found that the rate of H₂O₂ production is an important parameter to determine the induction period because there is a high correlation between the rate of H₂O₂ production and temperature rising rate. The chemical kinetics analysis indicated that production of H₂O₂ depends on HO₂. From the results of the analysis of HO₂, the activity of LTO and fuel consumption during the induction period seems to determine the production rate of HO₂.

In the previous study, it was shown that ignition delay time of n-heptane/air mixture co-existing with lower alkanes could not be explained by octane number. The OH inhibiting effect of co-existing alkanes is thought to be the most effective factor in the ignition of dual fuel system. However, there were few studies on both OH radical inhibiting effect and OH radical producing ability of lower alkanes. In this study, behavior of low temperature oxidation (LTO) of n-heptane in coexistence of lower alkanes was investigated from the viewpoint of OH generation rate that explain produced OH number when one OH radical is consumed. As a result, OH generation rate well explained LTO behavior. For example, termination timing of LTO and occurrence of LTO was expressed by OH generation rate.

A simple soot particulate emission model for a computational fluid dynamics calculation is developed based on a reduced kinetic model for a combustion process of four components of fuels (n-heptane, i-octane, n-cetane and hexamethylnonane) and a production process of pyrene (A4) with soot particulate production model by a moment method. To adjust a reaction rate of acetylene addition reaction of surface of soot particle, soot yield profile of the calculation result agrees with that of experimental data. Also, soot production profile against an equivalence ratio and temperature is reasonably obtained by this model. In addition, effect of ring number of nucleation aromatic hydrocarbon on the soot production process is investigated for reduction of calculation load.

HCCI is a combustion method to achieve high thermal efficiency and clean exhaust. However, HCCI combustion has low robustness and shows the cycle-to-cycle combustion variations. The variations are caused by entanglement of various factors and its mechanism is not fully understood. Therefore, the mechanism of the variations was investigated by using neural network. First, several models on the cycle-to-cycle variations of an HCCI engine were developed with the feedforward neural network and the convolutional neural network. Then, the sensitivity analysis using the models were implemented. As a result, it is clarified that the cycle-to-cycle variations are caused by the influence of the internal EGR, which are shown in other experiments. It is also shown that the factors for the cycle-to-cycle variations depend on the control modes of the internal EGR; the exhaust gas rebreathing mode or the negative valve overlap mode. In addition, the negative valve overlap mode shows different variation mechanisms for its scale.

In dual fuel engines (DFE), it is known that thermal efficiency and emission improve at medium and low load by adapting double injection. However, the improving mechanism of the combustion by adapting the double injection is not clarified. Therefore, in this study, the effect of double diesel fuel injection on the combustion of DFE using natural gas (city gas 13A) at low load was investigated by analyzing direct photographs of the combustion. The experiments were conducted using an engine with a see-through combustion chamber, remodeled by a single-cylinder engine, changing the diesel fuel injection timing with a common rail injection system. As a result, identification between a weak luminescence caused by pre-mixture and a bright flame caused by soot was possible, and by adapting double injection, high thermal efficiency was achieved and the combustion by pre-mixture was promoted in a wide area. However, a clear identification between self-ignition of premixed and flame propagation of natural gas could not be confirmed.

The performance of CO₂ capture from a gas-engine exhaust based on physical and chemical techniques were investigated. A small-scale chemical absorption plant using mono-ethanolamine solution was applied to a gas-engine exhaust. The CO₂ capture rate and the capture energy were evaluated. In addition, the adaptability of a CO₂ separation membrane to a gas-engine exhaust was examined using a model exhaust-gas. The experimental results indicate that the capture rate of tested membrane can reach 80%, and CO₂ is concentrated from 11.7% to approximately 50%. The capture energy under an ideal condition is estimated to be on the equivalent order of the practical chemical absorption plant.

As natural gas has low carbon structure and high octane number, it is beneficial for CO2 reduction and knock mitigation, respectively. Diesel and natural gas dual fuel combustion can be conducted under high compression ratio and lean premix conditions which contribute to high efficiency. This study aims to investigate how does the mixture condition such as oxygen fraction, intake pressure and the quantity of pilot diesel effect the DDF combustion. The experiments were conducted on rapid compression/expansion machine at two different control methods with the total calorific value of input-fuel kept constant: One is a constant intake-pressure condition assuming the control by EGR without using throttle, and the other is a stoichiometric condition that keeps the overall equivalent ratio of 1.0, which assumes control using EGR and supercharging for the purpose of utilizing three-way catalyst. From the experimental results, requirements of intake pressure and oxygen fraction at different natural-gas equivalence ratios for ensuring the stable ignition and the high combustion efficiency were discussed.

In this study, the FEM model of the piping support used in the experiment was developed for the purpose of evaluation for the damages such as buckling and fatigue failure. The numerical analysis for the static load experiment of piping support was conducted by using the developed FEM model. The FEM code "Abaqus" was used for the analysis. In order to validate the FEM model, the comparisons with analysis and experiment were performed. In the comparisons, good agreement between the load-displacement relationships of analysis and experiment was observed. In addition, the sevesral local strains of analysis were also in good agreement with those of experiment. Therefore, the validity of the FEM model was shown.

In piping systems equipped with elastic-plastic pipe supports as seismic response reduction design, the neighboring pipe supports are suspected to fail one by one when the elastic-plastic pipe supports are deformed extremely by seismic motions beyond design basis, which is called a zipping phenomenon. This is why excessive loading is added to the neighboring pipe supports due to change of the loading distribution of the whole piping systems by the extreme deformation of the supports. To judge the failure possibility of the piping systems in the severe event beyond design basis seismic motions, a simple screening method was proposed based on the idea of Allowable Support Span Method.

To confirm applicability of the inelastic response spectrum method to seismic response analyses of piping systems, the analyses results of a simple piping system are compared with the test results. The results are consistent and applicability of the method on simple piping systems was confirmed.

Elevators are essential for means of vertical transportation. In recent year, elevators to be installed in high-rise buildings are long stroke, thus the elevator ropes are longer. High-rise buildings have longer natural period than conventional buildings. As elevator ropes become longer, the natural period of the elevator ropes become longer as well, and get closer to the natural period of the building. Consequently, the elevator ropes collide against hoistway when the elevator ropes vibrate by an external force, such as a strong wind and earthquake. Secondary damage such as containment of passengers and elevator service stop may occur. Therefore, in this research, we aim to design elevator that can be operated even after the earthquakes. In this report, we examined effectiveness of elevators using intermediate transfer floors for damage reduction of ropes. In the analysis, the collision load of the main rope of car side was examined when the lift stroke is divided two. The calculated results of the analysis confirmed that dividing the lift stroke reduces the maximum collision load of the main rope of car side .In the probabilistic risk assessment, we examined the probability of damaging of rope using the fragility curve. From the fragility curve, it was confirmed that dividing the lift stroke reduced the probability of damage of rope. Therefore, dividing the lift stroke is effective for reducing damaging of rope.

This paper proposes a special seismic isolation system featuring Ellipse-curved grooves bearing. The curvature ratio is an important factor of bearing friction character. The study showed the performance of response distance is proportional to friction coefficient, and considered with Equivalent Damping factor. Further the vibration test yield.

Japan is an earthquake prone country in the world. In particular, the Southern Hyogo prefecture earthquake occurred in 1995, and about 105,000 houses were completely collapsed. Accordingly, seismic technologies have been actively studied and developed. Within them, seismic isolation system dealt in this paper is one of the effective technologies. The seismic isolation system isolates a structure from the ground. Thereby, acceleration input to the structure can be reduced. Although, seismic isolated structures are very few compared to the total number of structures, seismic response of seismic isolated structures is recording in many cases. However, there are few cases of long term seismic observations. In order to improve seismic safety, authors consider useful to obtain seismic records and long term evaluation of seismic isolated structures in many earthquakes. In this study, the authors deal with a seismic isolation structure that continues seismic observation from December 2011 up to the present. In this paper, the authors investigated relationship between the spectrum intensity and the natural frequency of the target building by using seismic records. Moreover, the authors evaluated relationship between the natural frequency and the damping ratio of the target building. Next, the authors constructed the analytical model of the target building. The authors proposed the method that can be modified the physical parameters by using the above relationships in constructing the analytical model. After that, the seismic records and the analytical results that were obtained from constructed analytical model were compared. Consequent upon that analysis, the authors confirmed high accuracy of the analytical model.

It is important to ensure the earthquake resistance in important industrial facilities. a seismic isolation system has been applied into important industrial facilities because the seismic loading can be reduced. Accordingly, a seismic isolation system with rubber bearing has been studied. However, due to seismic condition, the increase of displacement is expected in seismic isolation device. According to seismic condition, the seismic isolation design with rubber bearing may be difficult. Therefore, in this study, An application of the FPS (FPS:Friction Pendulum System) was investigated. The FPS applies the principle of Friction Pendulum. The FPS can be designed conforming with displacement which occurs by seismic load. Furthermore, the FPS is a mechanical product, the vibration characteristics can be easily determined. In this paper, the seismic response analysis with simple analysis model was carried out so that the effectiveness of the FPS was confirmed.

Active vibration suppression technologies should have high performance and have been studied and applied over the years; however, because of unusability, the practical applications are limited for large objects. Therefore, we proposed the distributed general-purpose active vibration suppression system which can be applied for various relatively small-size equipment with add-on style when vibration problems have occurred, and have developed a network distributed controller which has the following features: high-response rate, compact size, low weight, and scalability of the I/O number. In this paper, the verification of active vibration suppression performance for information equipment or industrial equipment were described. As an actuator for damping, inertial actuator using multilayer piezoelectric devices was developed and the characteristics were investigated. Then, a biaxial active vibration suppression system with the developed actuator for a steel pillar which has two 1st-order inclining modes in two directions was constructed and the both modes were damped more than 15 dB.

This paper is concerned with wave analysis and wave control of periodic cascade-connected damped mass-spring subsystems. Mass, spring constant and damping coefficient in the system change periodically along the layers, and thus the coefficient matrix of the recurrence formula representing each layer dynamics changes periodically. The system is a generalization of our previous works for uniform and uniformly varying cascade-connected damped mass-spring systems. In this paper, we consider wave analysis and wave control for this type of the systems and derive the impedance matching controller, and discuss properties of the secondary constants. The characteristic impedances have positive real property which guarantees the closed loop stability, and the propagation constants have some properties for the system to be analyzed by traveling waves. A numerical example illustrates effectiveness of the impedance matching controller for vibration control.

In this paper an electromagnetic damper using blushless DC motor and capacitor was developed in order to make a semiactive damper simply, compact, more efficient capability and to void a mechanical loss. A brushless DC motor is contactless, and a direct drive is relatively compact. So it is able to make small and decrease a friction. It is not necessary to add bearing, coupling and supporting. The damping force is caused by energy dissipation of electric resistances at terminal ends of the motor. However, capacitors were inserted into the terminal ends with the resistances, this is a quite different from a conventional type. Test damper, which has a ball screw mechanism, was manufactured, and resisting force characteristics were measured in cases of delta- or star-winding configurations with the capacitors in parallel or series. And the theory of damping force was introduced. Finally, the experimental results were compared with the calculated result, and a dynamic property of the damper was confirmed.

We propose a method to control output amplitude of a neural oscillator according to the acceleration response of a structure in this research. A new control system for Active Mass Dampers (AMDs) consisting of a neural oscillator and position controller was proposed. Since the neural oscillator has self-excited oscillation during no external stimulus, it was difficult to directly use the output of the neural oscillator as the target displacement of the auxiliary mass of AMD. In addition, because the synchronization regions of the neural oscillator depend on the amplitude of external input, it was very hard to set the limit on the synchronization region of the neural oscillator within frequency bands of each natural frequency of the structure. In this paper, we discuss a method which enables the output amplitude of the neural oscillator to be controlled depending on the structure response amplitude by changing tonic excitation and restricts the synchronization region within the designated frequency band during operation. Numerical simulations showed that the method proposed in this paper should be effective for amplitude control of the oscillator and restriction of the synchronization area.

In order to enhance the conventional damper performance, we propose an impact damper by using a cantilever-type impactor. The impact damper consists of a rotational spring and an impactor operating on a main system which is cantilever beam with natural frequency 600Hz. The main system is damped by energy dissipation of collision of the impactor and the main system. The experimental results showed that the damping ratio of the main system increased 11 times by attaching the impact damper. However, it is difficult to observe the state of collision due to too small amplitude of the main system. In this paper, we modeled experimental apparatus as two degrees of freedom system of the beam and the impactor and analyzed it based on the principle of impact damper. The analytical results showed qualitative agreement with the experimental result. From the analysis results, we can infer that the impact damper collides with the main system in the experiment. We propose an effective analytical model of experimental apparatus to determine the dynamic characteristics of the impact damper.