The ultra-compact mobility has positive characteristics as easily make turns owing to their compactness and low environmental impact because of using an electric motor as a power source. However, interior noise, which includes road and wind noise from the outside, has a significant impact on the comfort of an occupant in an interior space. We aim to create a new active noise control system for ultra-compact mobility to provide a comfortable interior sound environment. The feature of our proposed system is focused on interior sound design control for providing ride comfort according to various situations and the space preference of a passenger not only noise reduction. In this study, we considered the effect of interior sound for the driver under the driving condition. Regarding comfortability evaluation, we used an appearance rate of brain wave which is one of the biological information for quantitative evaluation and virtual analogue scale which is one of the subjective evaluation methods. Both evaluation methods were used to make a quantitative comfort evaluation.

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The authors have proposed to mount a small active seat suspension on the seat as a way to improve ride comfort. In this paper, we investigated quantitative and objective method for evaluation of ride comfort. In addition, participants evaluated the feel of ride comfort in the experiments by a visual analog scale (VAS), and the results were digitized to VAS values which were able to quantitively evaluated the ride comfort. Moreover, the relationship between participants’ biological information and their VAS values was modeled by using multiple regression analysis, and an estimation function of the occupants' ride comfort was established from the model. Therefore, the possibility of objective evaluation for subjective ride comfort was investigated using the model.

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In the current automobile industry, the demand for ultra-compact mobility as a means of transportation for elderly people and other travelers, has been increasing. The effect of vibration on the ride comfort of these vehicles is significant because of their small size and low weight. The vibration will increase the discomfort perceived by persons in the vehicle. Therefore, it is necessary to develop a vibration control system for safe and comfortable driving. To improve ride comfort, this research group proposed an active seat suspension using a voice coil motor at the seat section of the vehicle. In this study, we focused on visual analog scale (VAS), and two questions, comfort and drowsiness, which are elements of riding comfort, were provided to clarify the effect of vibration on psychological.

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Ultra-compact mobility has been demonstrated to have needs in various situations for short-distance travel in the local area. Itis expected to spread further by setting new standards and promotion by Ministry of Land, Infrastructure, Transport, and Tourism in Japan, and expected to be used by various drivers. However, there is no equipment such as power steering that reduces the driver's steering burden, and flexibility of driving posture is only driving seat moving back and forward because of the small size of the vehicle. From these reasons, some drivers operate the steering wheel in an uncomfortable driving posture. Therefore, a steer-by-wire system, which transmits steering operation to electric signals and steer the tires by an actuator, is expected to reduce the driver’s burden of steering operation by unreserved layout of the steering wheel. In this study, we established a two-dimensional model of the driver's arm to estimate a comfortable driving posture for each physique of the driver, and the effects of differences in physique and gripping position on the driver's joints were conducted. As a result of the simulation with changing the height of the steering wheel, it shows that the shoulder joint burden was more reduced than the elbow joint one.

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Transportation which can be easily used is required in areas where public transportation is inadequate. Due to solve this issue, ultra-compact mobility is proposed. However, improvement of ride comfort for ultra-compact mobility is required. Therefore, active seat suspension is proposed for improving the ride comfort of ultra-compact mobility. The actuator, voice coil motor, is connected seat surface, and control vibration of the seat directly. Active seat suspension is a control system that vibration of the seat is controlled using the detected acceleration of seat surface. Generally, the feedback control algorithm, which uses displacement and velocity calculated by integration of measured seat acceleration, is applied in the control system of active seat suspension. However, a control delay and deviation due to the integration process could affect control performance. We focused on the vibration control system which fed back acceleration directly. Therefore, in this paper, the control system was analyzed to investigate control performance in the assumed actual road.

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Reduction in aerodynamic noise emitted from a pantograph is an important subject for reducing environmental impact and speed-up of high-speed trains. In the previous study, aerodynamic noise reduction method by smoothing pantograph head cross section, shifting pantograph head position, and applying porous material were proposed. In this study, a study for practical application of these aerodynamic noise reduction method is carried out and improved pantograph head and its support are developed. From a wind tunnel test result, it is clarified that these aerodynamic noise reduction method can reduce aerodynamic noise at 2.7dB compared to the currently used pantograph.

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A Topology optimization attracts attention as a useful technique because of its flexibility in the design and applied to the various fields. Focusing on the acoustic field, there are some studies on the optimization design of an acoustic muffler by topology optimization. In the conventional topology optimization method, however, an optimal shape depends on the initial shape since sensitivity analysis is used. This paper presents a design method of an acoustic muffler using topology optimization based on genetic algorithm and shape expression method by Radial Basis Function Network. This method realizes obtaining a global optimal solution and representation of complex shapes with a few parameters. The proposed method is applied to the shape optimization problem of an acoustic muffler. The optimized result of an acoustic muffler is presented to show usefulness of the proposed method.

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As machines become more complex, it becomes more difficult for human beings to monitor the condition of the machine by only observing it from outside or listening to the operation sound. In order to prevent serious accidents, it is necessary that the machine informs the condition to human beings instantaneously, and that human beings respond appropriately. That is, the human-machine interface is important. For example, when human beings drive a car, visual, auditory, olfactory and tactile senses are used. For the visual sense, it is used for grasping the map information displayed on the car navigation system in addition to grasping the road and traffic conditions, so there is no margin for it. For the auditory sense, it is used for listening to music to relax in addition to grasping the road and vehicle conditions, so there is no margin for it. For the olfactory sense, it is used for grasping the vehicle condition by an unusual odor. For the tactile sense, it is used for grasping the road condition and vehicle motion. It is considered that there is a margin for it, since the sensory receptors for the tactile sense are widely distributed. Then, we have been proposed that vibration stimulus using a chair with a built-in vibration generator applying speaker technology are used to inform a driver about the risks. In this study, impressions on five simple vibrations were confirmed by factor analysis as basic data for designing vibrations suited to the situation.

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We performed a noise analysis of a sirocco fan by simulations and experiments using a sound-transparent wall that the pressurized condition is imposed to the impeller. It is obtained that the sirocco fan generates both the noise of DFN and large turbulent noise. The turbulent noise is mainly located from the end of scroll to the exit of scroll casing. The relative velocity and the circumferential variation of it is large about the end of scroll. The leading edge separation is occurred and the separation generates the large pressure fluctuation on the blade surface that the circumferential relative velocity becomes large at the inlet of blade. The sound source is mainly located at the leading edge of the impeller blade from the end of scroll to the exit of scroll casing.

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In order to demonstrate the noise reduction technology for aero engines such as acoustic liner panel or noise reduction exhaust nozzle, Japan Aerospace Exploration Agency (JAXA) has introduced a small turbofan engine and conducted outdoor noise measurement tests. One of the most important phenomena during the engine operation is vibration of the engine and its test equipment. Excessive vibration causes damage or deviation of parts, and if the fragments collide with rotating blades or combustors, it will cause a fatal damage to the engine. In this study the vibration characteristics of the engine and its equipment are investigated by the order analysis. The results show that engine vibration is dominantly caused by the rotations of both fan and high-pressure shaft while vibration of engine stand is excited at its eigen-frequency.

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In this study, numerical prediction of far field sound generated from a small box fan by using the decoupled method with large eddy simulation for incompressible flow and with computational aeroacoustics (CAA) in effect of sound reflection on test facility is performed. It is investigated the influence of 2 types grid of prism mesh and tetra mesh around blades on performance and aerodynamic sound spectrum. Also, far field sound spectra by CAA at observation point are compared to prediction by Curle’s equation(2) based on calculated fluid force on blade surface. As a result, sound field distribution in effect of the sound reflection has different characteristics for sound field with free space.

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Numerical simulations of aerodynamic noise by a hybrid method of combining large eddy simulation (LES) and the Lighthill’s acoustic analogy are expected to be used as a development tool for low noise products. In the present paper, the Lighthill dipole source introduced by Green’s theorem is applied to predict aerodynamics noise induced by a fan in semi-closed space, e.g. cooling fan of motor. The present method enables efficient sampling of Lighthill quadrupole source in a rotational region. The simulation results for the sound spectra show good agreement with the experimental results.

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Generally, the difference method and the finite volume method are used for the hydrodynamics acoustic simulation which is time-evolving. The particle method is used for the fluid time-evolving simulation same as the difference method, but no example of it was used for the fluid sound simulation can be seen. Therefore, in this research, we evaluated the usefulness of the particle method by using the SPH method, which can handle compressible fluids, for simple hydrodynamics acoustic simulation.

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Active noise control (ANC) is a technology that reduces the sound pressure of noise by causing sound waves of the same amplitude and opposite phase to interfere with the noise to be controlled. From the viewpoint of wavefront interference, a noise reduction effect can be expected for low-frequency noise with a long wavelength. We target environmental noise that is generated from factories and power generation facilities and propagates to general houses far away. We are studying how to reduce the energy transmitting into the room from walls and windows by applying ANC. In this paper, ANC is applied to the wall of a real house and the effect of reducing indoor noise is verified by experiments.

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In this paper, we indicate the probability of the sound attenuation effects in the area for the radiated sound from the engine. Nowadays, the attenuation of the airplane noise is need. In this research, we consider the radiated sound from the engine fixed at the ground. This is assuming the taking off and landing noise. At first, we indicate the sound attenuation effect in the area is achieved for the selected lobe mode by using the eight speakers and the eight microphones with the numerical simulation. In case the distance between speakers and microphone is long, the attenuation effect over 6 dB in the backward area of the microphones is verified. Second we indicate the sound attenuation of each microphone are achieved by using the recorded sound radiated from the engine. In case the distance between speakers and microphone is short, the attenuation effect from 5 dB to 10 dB at almost all microphones is verified. From these simulation results, we verified the probability of the sound attenuation effects in the area for the radiated sound from the engine.

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The ultra-compact EV has been new transportation system in Japan recently. The vehicle uses an electric motor as a power source instead of a gasoline engine or a diesel engine, it not only has a low environmental impact, but also does not generate noise from the engine. Therefore, the noise input into the vehicle mainly consists of road noise from the tires and wind noise. For the interior noise problem, we focused on a giant magnetostrictive actuator, which is small in size and generates a high output and proposed an active noise control system using the wall vibration generated by the giant magnetostrictive actuator, thereby confirming the silencing effect. In this study, we used an experimental vehicle exterior and conducted noise reduction experiment using feed forward control by all pass filter. In the experiment, we changed phase degree of phase compensate in all pass filter and considered noise reduction effect by each phase degree.

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Measurements and theoretical studies related to wheel/rail noise have been carried out widely and thoroughly. The wheel/rail noise from 250 Hz to 4 kHz significantly influences the wayside noise along railway lines. However, when a train runs on a sharply curved track, squeal noise due to wheel and rail interactions in the frequency range of 1 kHz to 5 kHz has greater contribution to the total wayside noise. In this paper, scale-model tests with a running vehicle in RTRI were carried out in order to understand squeal noise and develop the measures. It is found that rail vibrations related to squeal noise are reduced by lubrication on the surface of the rail. These trends show good agreement with the results obtained with an actual train vehicle in previous studies. Furthermore, for the rail roughness and rail pad stiffness, significant difference in rail vibration related to squeal noise can’t be seen in these tests.

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A prediction model, which estimates the Shinkansen wayside noise around tunnel portals, has been proposed. In the model, the wayside noise consists of the noises from trains in both open section and tunnel section. In addition, the noise from tunnel section is composed of two sound contributions: noise directly emitted from a vehicle in a tunnel, and multiple-reflection noise in the tunnel. In this paper, the model is improved about the multiple-reflection noises by introducing both the screen effect due to vehicles in the open section and the directional characteristics of the sound source of the multiple-reflection noises. Then, the validity of the model is shown by comparing the results in the field test with the results using the model.

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When trains run at higher speed, local wear on a wheel tread could make bridge noise and wayside noise greater. As the first step, to predict both the noises at higher-speed sections, an attempt is taken to estimate the rail vibration at a highspeed section by using that obtained at a low-speed section in this study. In the estimation, the vibration properties of a wheel, track and contact spring at each section are used, and it is assumed that a wheel roughness is greater than a rail roughness at the spatial frequencies where the effect due to the local wear appears. The rail vibration is also measured at the high-speed section. It is found that, at the high-speed section, the estimation shows good agreement with the measurement in the frequency range where the local wear has a stronger effect.

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Elastic vibration of a railway vehicle carbody causes deterioration of ride comfort since the natural frequency of the vibration below about 10 Hz is the frequency range that is known to be a sensitive frequency range for human. Vibration reduction methods for the elastic vibration below about 10 Hz of that have been researched to improve the ride comfort. However, in recent years, the vibration in a frequency region above 10 Hz also causes deterioration of ride comfort along with speed up of railway vehicle. Therefore, it is necessary to understand vibration characteristic in a high frequency region to research vibration reduction methods. At first, this paper describes the vibration experiment of a Shinkansen type carbody in a stationary position. In the experiment, with the wireless three axis accelerometers to understand the detailed elastic vibration characteristics in high frequencies, the accelerations at the floor and the roof were measured at more points than in the usual. As a result, it is confirmed that the carbody vibrates with the three-dimensional vibration shapes and has the complex vibration characteristics in the high frequency region above 10 Hz. In addition, it is found that the wireless accelerometer enables us to measure the accelerations of the floor and the roof more easily than a conventional wired accelerometer.

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[in Japanese]

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In this paper, we evaluated the impression of the composed noise of air exhaust sound and air compressor sound which are typical noises of home medical equipment, in order to examine a method for quantitatively evaluating the uncomfortableness of the noise of home medical equipment. As a result, it was confirmed that there was a high correlation between the subjective evaluation value of uncomfortableness and the loudness and sharpness of the psychoacoustic metrics when only exhaust sound was heard. In addition, it is suggested that the uncomfortableness of the air exhaust noise that can be heard in the complex noise composed of the air compressor sound and the air exhaust sound can be quantitatively estimated from the loudness and sharpness calculated by the masked loudness method.

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Acoustic impedance of resonators or perforated plates with a backing cavity is affected by sound pressure level and flow velocity. To understand why they change the acoustic impedance, we investigated the flow field around a resonator by used of numerical fluid analysis. We used a quasi-three-dimensional model of a resonator in the flow duct. The sound and the grazing flow enter from an inlet of the flow duct. The frequency was set to the resonance frequency of the resonator and the sound incident pressure was varied at 3 levels. The grazing flow velocity was set to various values. The non-reflection boundary conditions for pressure fluctuation were applied at both ends of the flow duct. We used pressure fluctuation at two points to calculate the acoustic impedance: One is at the end of the resonator and the other is at the point in a flow duct near the mouth of the resonator. When the grazing flow is slow, the resistance, real part of the acoustic impedance, depends on incident sound pressure. As the incident sound pressure increases, the resistance increases. When the grazing flow is high, the resistance depends on incident grazing flow. As the grazing flow increases, the resistance increases. These results are qualitatively consistent with the experimental results.

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The present paper deals with the problem of reproducing different sounds in different areas in the same sound space. As a solution to this problem, find a filter that enables wideband control in the time domain by the method using Fourier transformation. Calculate the transfer function from each sound source to each control point for each frequency using Fourier transformation. Find the frequency characteristic of each sound source that controls the area using acoustic contrast control (ACC) based on the transfer function, and find the filter for controlling by performing discrete inverse Fourier transformation. Passing the input signal through its filter allows the input sound to be divided into a bright zone (area that sound can be heard) and dark zone (area that sound can’t be heard) in the control area. By applying this method, simultaneous reproduction of different time series signals in different area becomes possible.

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In the casting field, soaring of fossil fuel cost and destruction of the global environment have become serious issues. We must be replacing coal coke and carburization material with solid bio-fuel that be able to realize environmental protection while accommodating economic growth. This study has purpose for quantitative measurement of the carbon effect in casting process by solid bio-fuel; Biocoke. Our previous studies have found that can make the casting of carburized molten metal by Biocoke's bio-carbon, but the carburizing process has not been clarified. An experimental equipment is using high-frequency induction melting furnace. For quantitative measurement of the carbon effect, contact by surface of Biocoke and melted metal. Especially, carbon effect was suggested with various degrees of carbonized Biocoke. From the results of experimental, it is considered that Biocoke is carburized after being carbonized above the molten metal. Furthermore, it was found that the carburizing effect in the casting process increases in the order of semi-carbonized Biocoke > carbonized Biocoke > Biocoke, and the carbonization property of Biocoke depends on the heat environment temperature and affects the carburizing effect.

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A coal coke and carburizing material has used in the casting process, environmentally friendly casting is required. We need shift from fossil resource to bioenergy. In the domestic, the rice husk is discarding about 200,000 ton per year. However, contains about 14wt.% by the amorphously SiO₂ (silica). As a well-known fact, when introducing rice husks as a silica material in the casting process, it has been confirmed that a part of the contained silicon is silicified into cast iron. A silica alloy in the casting process is contained as a crystalline material. In this study, Biocoke provide two type by mix crystalline silica reagent and amorphous silica reagent in the cedar base material (does not exist silicon). We found that the silicon content in the melted casting has increase in both mixed crystalline and amorphous Biocoke, and silicon was hardly released into the atmosphere, and to saturate according to elapsed time.

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Biofuels, alternative energy that is currently utilizing in many sectors, struggle as a coal coke substitute in the iron and steel industry. This research focuses on the development of pre-carbonized solid bio-fuel (bio-coke), which can be implemented in the iron and steel industry. The biochemical structure of the bio-coke product that changes after the production process is essential foundational information that has an impact on bio-coke characteristics and functions. Notably, in the mass-production scale, when various types of biomass are mixed as feeding raw materials. Influences of lignocellulose (hemicellulose, and lignin) fraction in the structural bonding is a promising range that needed to be explored. The ATR-FTIR spectroscopy observed the fundamental chemical structure of the Japanese cedar based bio-coke with various additional lignin and hemicellulose ratio. Different additional conditions are 0, 2, 5, 8, 10, and 15 wt. % for both lignin and hemicellulose. The collected spectra were analyzed using the mathematical function, second derivative, which revealed the quantitative variation of the observed bio-coke samples. In O-H stretching of intra-chain crystalline cellulose, a higher amount of lignin orderly decreased the peak at 3334 cm^-1 (O3-H3…O5 position). While increasing the hemicellulose ratio from 0 to 5 wt. %, rose the intensity of a peak at 3273 cm^-1 (O2-H2…O6), and dropped at a higher rate.

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FT-NIR spectroscopy has the potential to be an index for the degree of the formation of BICs using the changes in the hydrogen bonding or CH stretching vibration in terminal groups between the materials (reagents such as cellulose and cellobiose, botanical wastes from coffee beans and tealeaves) and various processing conditions of BICs. FT-NIR spectroscopy is a grate method for the BICs analysis because it is able to measure the vibrational spectra without destruction and pre-preparation for the spectroscopic measurement. The other reason why NIR is that this spectroscopy is hard to include noises from some contained materials in BICs. In the other hand, NIR spectra need the statistics analysis called “chemometrics” because these spectra show very broad and overlapped band. Changes of these overlapped bands are easier to interpret than MIR regions because MIR region has larger amount of information from many kinds of vibrations. Results of the chemometrics need the careful consideration for the changes between analytical results and intentionally perturbations because sometimes chemometrics results do not have the chemical meaning. Raman and THz spectroscopy are used to understand the actual chemical changes with perturbations by comparing with the results of statistical analysis.

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The purpose of this paper is to improve the energy density and quality of low-grade biomass by appropriate pretreatment, and to study the improvement of transportation efficiency and power generation efficiency. To solve the problem of clinker formation due to ash, we focus on the hydrothermal method as a technology for extracting ash from raw materials. In addition, through a Literature review, the pretreatment technologies that can be applied have been systematically organized, and proposals for effective utilization measures of low-grade biomass have been made. In order to understand the characteristics of agricultural biomass, the characteristics of rice husk and rice straw were analyzed by literature review and TG-DTA analysis. An experiment on hydrothermal treatment was conducted to reduce the ash content of agricultural biomass. In addition, the applicability of pretreatment technology for agricultural biomass in Southeast Asia and China has been evaluated.

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In this study, we attempted to understand the actual condition of feedstock supply after the construction of FIT in Nara prefecture in order to improve the system for utilizing unused woody biomass in cooperation with the local community. Specifically, we visualized the amount of biomass available and road information by GIS and studied the ideal system for biomass utilization after the implementation of FIT. We also visualized the amount of transport per hour with road information, estimated the amount of chip distribution, and examined the inflow and outflow of wood. As a result, it was shown that the proposal of different utilization systems in the northern and southern part of Nara Prefecture was effective.

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This report focuses on the infectious waste discharged from small medical institutions and aims to build a system that utilizes the IoT to promote the appropriate treatment of medical waste by streamlining the small-lot collection operations. Specifically, a traceability system based on an activity record management system will be introduced, and a vehicle dispatching system using AI will be designed for future implementation. As the preliminary stage of system construction for the appropriate treatment of hazardous waste at medical institutions, we grasp of the actual situation of infectious waste discharge, collection, and transportation. This was done by conducting local interviews and questionnaire surveys in three collection and transportation companies and 260 small medical institutions located in the “I” city. In addition, we conducted a function verification test of the activity record system as a preparatory work for building a system using IoT.

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In Southeast Asia, where the population and economy are growing rapidly, active efforts to utilize the biomass energy are taking place. In particular, there are high untapped energy potentials from the agricultural biomass and its residues. In order to promote effective development and use of biomass energy conversion technologies, it is essential to evaluate their level of readiness status objectively. In this study, we created a database of energy conversion technologies for agricultural biomass in international projects of the Japanese companies and organizations and evaluated them by using the TRA (Technology Maturity Assessment), GIS mapping and LCCO₂ methodologies. Specifically, we presented an evaluation case study focusing on Indonesia and proposed a dissemination strategy based on the evaluation.

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We conducted a survey about the feasibility of introducing MBT (Mechanical Biological Treatment) systems for waste incineration facilities linked with sewage treatment facilities. We focused on this topic because the decline of Japan’s population has caused the need of expanding service area of waste treatment facilities and optimizing the efficiency of energy use. From the questionnaire surveys distributed, we received 64 responses from waste incineration facilities, mainly in cities designated by government ordinance, and 78 responses from sewage treatment facilities. Our analysis results showed that 4.7% (3 cases) of incinerators and 3.8% (3 cases) of sewage treatment facilities have the possibility of installing both incinerators and sewage treatment facilities, which is unprecedented in Japan. Municipalities with more frequent communication between departments tended to choose the same pattern we offered, suggesting the importance of inter-departmental cooperation.

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In this paper, we investigated the potential of the Waste to Energy for Industry heat utilization from the Industry in Chiba prefecture. Specifically, we evaluated the energy efficiency of a municipal waste treatment facility in Chiba prefecture by using the R1 formula. From our evaluation results, we found that the municipal waste treatment facility needs to optimize its waste heat utilization system to achieve a higher energy efficiency. Furthermore, we conducted a questionnaire-based survey to identify the condition of steam utilization, the demand for steam derived from waste incineration, and the amount of waste emissions which can be used as an alternative fuel in the Industries in Chiba prefecture. The survey results were then visualized by using the QGIS software. We found that there are many manufacturing industries with high heat demand in Keiyo seaside industrial area. The demand included steam of 400°C×3.9MPa(gage) for each facility and a total supply of alternative fuel.

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Ensuring access to affordable, reliable, sustainable, and modern energy for all is the goal number 7 within the Sustainable Development Goals (SDGs). While most of the countries in the Southeast Asian region aim for universal electrification within 2020 to 2030, it is predicted that a couple of millions of the population will not have access to electricity by then due to various reasons. Among them are challenging geographical terrain and the low population density in rural areas. In this study, we analyzed the current situation of the population living in the off-grid area through field surveys, estimated their energy demand, and projected the future growth of energy demand. As case studies, we selected three communities in Myanmar, Indonesia, and Laos. Also, we proposed a strategy to appropriately introduce renewable energy in the communities based on our analysis and observation.

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BDF (Biodiesel Fuel) is the mainstream as a method for recycling waste food oil. However, since there are many concerns that by-products are generated during the generation process and these are treated as wastes, their use is decreasing. Thus, this study proposes a regeneration method of SVO (Straight Vegetable Oil) fuel by UFB (Ultrafine Bubble) water without transesterification. Therefore, water emulsified fuel (W/O) was used as a fuel reforming means, and the mixed water was changed to tap water, pure water and UFB water, and cause to separate. After that, the supernatant was collected and the peak was detected by a Gas Chromatograph. As a result, when UFB water was used, the reduction of the hydrocarbon peak was the largest. This indicates that radicals are strongly related to the Nano number density in UFB water. The radicals in the UFB water act to reduce the hydrocarbons in the fuel, which will also help reduce the specific odor.

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In recent years, research and development and practical application of biofuel and waste food oil regenerated oil have been advanced as alternative fuels for light oil. However, waste oil regenerated oil has a high viscosity and contains a large amount of impurities, so there is a concern that clogging of filters and the like may occur. In addition, the increase in pollutant concentration has become a problem due to poor combustibility. Thru, in this study, we focus on waste food oil for which waste treatment is a problem, and we expect an improvement of combustibility by converting waste food oil into a recycled fuel as a water emulsified fuel. Therefore, we expect to reduce of NOx and PM concentration by increasing the water content, and we develop a technology of environmental reduction method.

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The production and consumption of carbon fiber reinforced plastic (CFRP) are increasing year by year, and research and development on carbon fiber recovery from waste CFRP is more necessary. In this study, we develop a new recycling method by direct heat treatment using electromagnetic waves. Heating behaviors of three kinds of the CFRP pieces with different structures were clarified using a high-frequency induction heating device (about 300 kHz) with a six-turn coil and a single-mode microwave irradiation device (2.45 MHz). Using the high frequency band, the woven fabric sample was the most heated and the temperature rose to around 300 ℃. At this time, changes in appearance due to thermal decomposition and volatilization of the resin were observed around the sample, and about 30% of the resin content volatilized. Using the microwave band, unlike the high frequency band, thermal decomposition of the resin occurred in the uniform fiber direction sample, and almost 90% of the resin content was removed.

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With the autonomous driving technology advancements in the recent years, significant changes in the arterial industry has been expected. However, its application to the venous industry has not received much attention. On the other hand, the situation surrounding the venous industry is changing every day due to the labor shortage and aging problems. In response to this situation, we propose a "modular compact mobility" that has a module above its chassis. The module can be changed flexibly depending on the purpose and a prototype can be developed. In this report, based on the demonstration experiments at the Waseda Festival, we consider its use as a garbage collection solution for predicting future use at the next Osaka Expo. At the same time, we proposed and evaluated the utilization of mobility in various regions and considered its economic and environmental values.

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Torrefaction has come to attract attention as one of the promising methods for improving the fuel properties of solid biofuels. This is because not only higher heating value (HHV) but also several functions such as grindability and water absorptivity are reformed. Since HHV of torrefied solid biofuel is affected by biomass species and its the progress degree of torrefaction, the relationship between torrefaction conditions and HHV for various biomass species has to be clarified to produce torrefied solid biofuels with a predetermined HHV. In this study, in order to estimate the HHV of torrefied Japanese cedar and rice straw, the effect of biomass species on pyrolysis kinetics is investigated with Two-step pyrolysis model. It is found that energy properties for various torrefied biomass can be determined with the simple linear expression of mass yield.

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From the perspective of global warming, reduction of CO₂ emissions is being promoted. In the steel industry, coal coke, which is a fossil fuel, is used as a fuel and a reducing agent in a melting furnace（cupola furnace）.This fossil fuel causes global warming due to CO₂ emission, and its use is being regulated from the viewpoint of global environmental conservation. In addition, domestic production of coal coke is difficult. From the viewpoint of depletion of fossil fuels, development and practical use of alternative energy sources are required. Therefore, what was developed as an alternative fuel for coal coke is bio-coke（hereinafter BIC）,which is a solid fuel derived from biomass. However, it is difficult to understand its carbonization behavior in the melting furnace because the basic carbonization behavior of BIC has not been clarified. Therefore, BIC of cedar and bamboo with different forming temperatures and pellets of cedar and bamboo were prepared, and the observation of carbonization behavior and the compression test was performed. As a result, there was no difference in the mass change rate of cedar BIC and pellets depending on the molding temperature. On the other hand, for bamboo, although there was no difference in the total carbonization time, the mass change rate at the beginning of carbonization was larger for pellets than for BIC. In addition, the compressive strength between 30s and 60s exceeded 50MPa for both cedar and bamboo, and it was found that they had sufficient compressive strength during casting.

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Rocket fuel is mainly developed based on solid fuel and liquid fuel. Liquid fuel has environmental pollution instead of high propulsion power and solid fuel has hard ignition control instead of high-density fuel. The hybrid rocket has developed by combine double merits of liquid fuel and solid fuel properly according to the purpose. However, both are fossil fuels and have problems with resources and environmental pollution. New High density solid bio-fuel ”Biocoke” can be produced domestically and has carbon-neutral properties, its use as a substitute for rocket fuel is significant. Especially, Biocoke burns stable and slowly, it has less thrust than conventional fuel and cannot obtain propulsion. This study investigated a slow combustion characteristic while homogeneous combustion by adding a highly combustible aluminum powder in Biocoke. It is found that blended aluminum powder affects in the char combustion zone.

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One of the CO₂-free hydrogen production methods is a system that produces hydrogen by the water electrolysis method using surplus electricity from renewable energy, but the hydrogen production efficiency itself is not high because the power consumption is very large. Therefore, the development of a device that can produce hydrogen from water with low power is desired. We have been developing a hydrogen production method that decomposes ammonia with atmospheric pressure plasma. We thought that atmospheric pressure plasma has a high electron temperature and can generate hydrogen by decomposing gaseous water (water vapor) with low power consumption. In this study, steam generated from distilled water and alkaline water (NH₃) was decomposed by electric discharge in a cylindrical plasma reactor, and the hydrogen generation behavior at that time was investigated.

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Nitrogen oxides (NO_x) and sulfur oxides (SO_x) are the major components of environmental pollution; therefore they should be removed. NO oxidation process by using ozone gas and NO_x removal process by using Na₂SO₃ solutions combined with semi-dry desulfurization equipment to glass melting furnace have been investigated. Regarding exhaust gas treatment in glass melting furnaces, desulfurization and particulate collection are performed by a semi-dry desulfurizer using caustic soda (NaOH), a dry electrostatic precipitator and a bag filter, respectively. However, it is difficult to use the conventional selective catalytic reduction method for denitration due to the high concentration of SO_x and sticky dust in the exhaust gas. Therefore, development of applicable denitration method is desired. In this study, we aimed to commercialize the plasma combined desulfurization and denitration method combining the semi-dry desulfurization equipment and the plasma combined denitration method. In a laboratory-scale semi-dry plasma combined desulfurization and denitration system, the effects of varying the simulated exhaust gas flow rate, component concentration, NaOH aqueous solution and Na₂SO₃ aqueous solution concentration and spray amount on desulfurization and denitration were investigated. As a result, in a laboratory-scale semi-dry plasma combined desulfurization and denitration system, NO_x removal was confirmed to have a maximum removal efficiency of approximately 80%.

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Diesel engines are widely used as prime movers for agricultural machinery, ships, construction machinery, etc., but NOx and Soot in exhaust gas are regarded as problems. Currently, the entire engine system becomes complex because the exhaust gas is purified using a post-treatment device. On the other hand, no countermeasures have been taken on the fuel side, and there are many reports that simultaneous reduction of NOx and soot could be achieved by using emulsion fuels, but at present it is not established yet. Therefore, we focused on the effect of the water content in light oil-water emulsion fuel on the operating characteristics of diesel engines. By using emulsion fuel, the heat was taken away by the latent heat of vaporization of water and the calorific value decreased, resulting in a decrease in output, but at a water content of 7%, the output was the same as during light oil operation. It was found that the NOx concentration decreased with the increase of the water content in the emulsion fuel as compared with the operation with light oil. Soot concentration also decreased linearly with water content.

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An incineration process is the most dominant method of the waste disposal in Japan. A stoker furnace incinerator is widely used for the waste incineration. In the stoker furnace incinerator, waste products can be sufficiently stirred and burned completely. Recently, low air ratio and high temperature incineration have been applied to the stoke furnace incinerator to improve efficiencies of power generations. However, they result in the increase in the amount of air pollutant NOx due to their higher flame temperatures. In addition, Exhaust Gas Recirculation (EGR) system, which is also applied into advanced incinerators, makes the NOx formation more complicated. In this research, NOx and other gaseous emissions from RDF char combustion were experimentally analyzed, investigating effects of exhaust gas compositions on NOx formations.

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In this study, we aimed to decrease emission of nitrogen oxide gases using intermittent discharges for a plasma sterilization device of contact lens. Although this device already has advantages such as low temperature, less emission of nitrogen oxide gases, low cost and safe, emission of nitrogen oxides is required to be a practical product. To sterilize contact lenses, a commercial contact lens vessel, which was able to be closed, was used. The volume of water in the vessel was 2 mL. The electrode consisted of an alumina plate of 0.2 mm in thickness and circle-shape aluminum tapes having 4-mm diameter. As the nitrogen oxides are generated at higher temperature, we aimed to reduce the temperature of the alumina plate down to a room temperature using the intermittent discharges which were operated by (1) 1 sec on/2 sec off, (2) 3 sec on/6 sec off and (3) 5 sec on/10 sec off. The sterilization of Geobacillus stearothermophilus (ATCC 7953) spores in water was completed in 80-minutes operation time including cooling time by the plasma off. As for the chemical species concentration, the nitrogen oxides were reduced by half compared to the case of continuous discharge, and the ozone concentration was successfully increased.

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At present, the air pollution in China and South Korea is very serious, among which particulate matter (PM) pollution is the main problem. In addition, the concentration of nitrogen oxides (NO_x) and Sulfur oxides (SO_x) in the atmosphere is increasing rapidly as a result of the growth of cars, factory emissions and the burning of crops. In Japan, the emission of NO_x cause photochemical oxidant, which has a great impact on human health. Researches on removal of PM and NO_x using a wet plasma reactor have been conducted. According to previous researches, it has been reported that NO_x and SO_x removal efficiencies can be as high as 99% by generating air plasma with flowing water using a wet-type plasma reactor. Considering the cost of equipment and the generation of harmful substances, simultaneously removal is extremely economical and effective in comparison with the conventional separate treatment technology of NO_x, SO_x and nanoparticle. Therefore, in this study PM, NO_x and SO_x are removed simultaneously using a one-stage wet-type plasma reactor, and each removal efficiency and PM capture efficiency are evaluated. From experimental results, PM capture efficiency of over 90% and NO_x, SO_x removal efficiency of over 95% are achieved, which verifies that the wet-type plasma reactor is useful for simultaneous removal of NO_x, SO_x, and nano-particle.

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Plasma activated water (PAW) has been studied as the remarkable technique for sterilization process, water purification and agriculture. Effective method to generate high concentration PAW is required. In this study, we invent a novel technique to generate PAW by combining microbubbles and plasma technology in a water recirculation system. Venturi type setup is used to generate microbubbles. The motion of bubbles in the pipe is measured by optical flow technique.

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Recently, ammonia has attracted the attention of many researchers as a carrier for efficient transportation and storage of hydrogen. In factories, it is desirable to use surplus ammonia not only as a hydrogen source but also as fuel (heat utilization) from the practical perspective. However, ammonia is incombustible and generates nitrogen oxides (NOx), which are harmful substances. In this study, the flame structure of ammonia was investigated and a burner was developed for the stable combustion of incombustible ammonia even in high-velocity airflow using a hydrogen flame stabilizer to simultaneously reduce the concentration of NOx. Specifically, (1) when the airflow velocity increased, turbulent mixing and reaction were facilitated and the flame length shortened; (2) a triple jet burner, which could stably perform highintensity combustion even in a turbulent flow field, was developed; and (3) the concentration of fuel-NOx could be reduced to under 300 ppm by enveloping the ammonia fuel in hydrogen flame, in which reduction zone formed.

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