To build a sustainable society, the utilization of solid biofuels is expected to replace coal and coal coke. In this study, we focused on wet torrefaction (WT) treatment and densification forming to produce solid biofuels with fuel properties comparable to coal. WT is advantageous for reforming high moisture biomass feedstock, and Japanese cedar powder with 83% and 95% moisture content is used as the WT experimental sample. The aim of the study is to clarify the effects of WT conditions (WT temperature, holding time, water/biomass mass ratio) and densification on the char yield of four types of solid biofuels, Fuel-R (raw powder), Fuel-WT (wet torrefied powder), Fuel-RB (raw densified biocoke) and Fuel-WTB (wet torrefied densified biocoke). The obtained results are as follows. The apparent density of WTB is larger than that of RB under the same forming temperature. Char yield is enhanced by densification forming due to suppression of volatile matter evaporation. Char yield of WTB at B/W=1/5 is higher than that at B/W=1/20. From the investigation on the effect of WT on the char absolute mass, it is found that both volatile matter releasing, and char leaching occurs in the case of WT at B/W=1/20. The optimal WT conditions for producing fuel with high char yield are found to be B/W=1/5 and WT temperature 240°C.

Skeletal muscle, which accounts for approximately 50% of the human body weight, plays an important role in maintaining physical function and health. Healthy skeletal muscle contractile function is essential for maintaining a healthy life and preventing disease. For this reason, research into maintaining healthy skeletal muscle across generations and environments, including training methods and therapeutic agents, is carried out daily. In vitro methods, in which specific nerve and muscle cells are removed from living organisms (in vivo) and studied in culture vessels, are effective in understanding diseases related to nerves and muscles and in developing therapeutic agents. Our research group had developed a three-dimensional cultured skeletal muscle, which is a mixture of collagen gel and mouse rhabdomere-derived cells (C2C12). In this study, we developed a device to non-invasively load skeletal muscle using the characteristics of artificial skeletal muscle and investigated whether artificial skeletal muscle is useful as a model of disuse muscle atrophy. The results of a comparison of loaded and unloaded samples showed that the device affected contractility.

A typhoon cause extensive damage to property and communities. Therefore, it is important to predict the intensities precisely. The development and attenuation of a typhoon depend on the momentum flux through the air-water interface. So, it is necessary to measure the momentum transport through the air-water interface. However, the measurement under typhoon on the actual sea is dangerous and the flow state changes drastically, so the measured value varies greatly and lacks reliability. In order to obtain a safe and stable flow state, laboratory experiments using a typhoon simulation tank that can reproduce ocean waves are considered effective. Therefore, in this study, we conducted laboratory experiments using the typhoon simulation tank, and attempted to measure momentum transport through the sea surface in a stable flow state. As a result, We were able to measure the amount of momentum transport with high accuracy. It was also found that the amount of transport does not depend on the measured distance.

In order to investigate the relationship between the shape and aerodynamic characteristics of a corrugated airfoil with two valleys in the low Reynolds number region, the lift-drag ratio was measured by varying the airfoil thickness and visualizing the flow. At Re = 4.0 × 10⁴, the maximum lift-drag ratio was 1. 4 times higher for the thick airfoil and 1. 6 times higher for the thin airfoil compared to the streamlined airfoil. For both types of airfoils, a stable circulating flow was formed in the valley at low angles of attack, along which the flow from the upstream top of the convex part flowed to the downstream airfoil surface, thereby increasing the lift. As the angle of attack increased, there was a backward flow from the second valley to the first valley, and the mainstream flow stalled away from the airfoil surface.

In recent years, demand for wind power generation has increased due to the requirements for renewable energy. Compared to large wind turbines, the micro wind turbines used in urban areas have lower power generation efficiency (power coefficient) because they are used in low wind speed environments. Therefore, this study focused on the winglet (WL) at the tip of the wind turbine blades to improve the power coefficient. This study investigates the relationship between the design parameters such as WL height, taper, and twist angle and wind turbine performance for a low tip speed ratio type horizontal axis wind turbine with winglets. Also, the winglets with Bayesian optimization was tested. From the experimental results, it was confirmed that the power coefficient was improved by 16% compared to the wind turbine without winglets.

The flow in the bronchial tube was experimentally investigated using a human bronchial tube model. Resin bronchus model that is made by 3D printer is provided for the experiment. a bent pipe is connected upstream of the bronchus model. Microbubbles were used as tracers to visualize the movement of particles. The areas to be photographed are the secondary flow in the curved pipe and around the first branch of the bronchial model. Velocity distribution is measured by PIV. Refractive index matching technique are applied to measure velocity in the bronchus model. In front of the first branch of the bronchial model, the velocity distribution of the inverse pressure gradient was observed. In the right and left bronchi, the position of the peak is more medially biased due to this effect.

We have developed an unmanned autonomous combine harvester for rice and wheat．This paper describes the development of autonomous harvesting technology and human and obstacle detection system.

剛部材と柔部材からなるテンセグリティ構造は，それぞれの部材に作用する圧縮力と引張力に抗する剛性を利用して静力学的釣り合いを実現しており，この性質は主に展開構造物として応用されている．柔部材の張力を弛緩させ，部材の連結点の可動性や不動性を付与することで，新しい機能を持つ構造の実現に繋がる挙動を示す構造設計の実現が期待される．本稿では，このような性質を持つ南京玉すだれに着目し，モデル化による数値解析を行い，剛性の評価と双対論を用いた安定性の評価を試みる．

An alloy (Cu35W65) consisting of copper (Cu) and tungsten (W) have been used as an electrode material od die sinking electric discharge machine (EDM) and resistance welding. A temperature of electrode becomes high at work which takes place heat production. The electrode material is demanded that the heat conductivities are large at the high temperatures. The information about dependences of thermophysical properties on temperatures is necessary to evaluate its performances as an electrode. So, we develop a new method¹⁾ to measure thermal diffusivity at high temperatures by using a light heating. This method is unique in that the heat source for temperature maintaining is also used as the heat source for temperature fluctuation. This report describes a comparison between experiments for dependence of thermal diffusivity on temperatures and the references for that. The thermal diffusivity is determined by the agreement of an experiment for the heat conduction with an analysis on the assumption of one dimension that is symmetrical around the center axis for an infinite rod²⁾ by using theoretical solution. Figure 2 and 3 show the dependence of thermal diffusivity on temperatures for stainless steel (SUS304) and Cu/W alloy.

To realize a super-leanburn SI engine with a very-high compression ratio, it is required to design a new fuel which could have low ignitability at a low temperature for antiknocking, but high ignitability at a high temperature for stable combustion. Ethane shows a long ignition delay time at a low temperature close to that of methane, but a short ignition delay time at a high temperature close to that of gasoline. In the present study, the antiknocking effect of adding methane with the RON of 120, ethane with the RON of 108, or propane with the RON of 112 to a regular gasoline surrogate fuel with the RON of 90.8 has been investigated. Adding each gaseous fuel by less than 0.4 in heat fraction advances knock limit in the descending order of SI timing advance of ethane, methane, and propane, and in the descending order of CA 50 advance of ethane, propane, and methane. Adding methane extends combustion duration slightly, but adding ethane or propane shortens it considerably. Namely, shortening combustion duration has a negative effect on advancing SI timing. The effect on advancing CA 50 is dependent on not the RON’s of the gaseous fuels but the rates of OH removal by the gaseous fuels. The antiknocking effect of adding each gaseous fuel to a premium gasoline surrogate fuel with the RON of 100.2 has been also investigated. The effect on advancing CA50 is not dependent on whether the liquid fuels have cool-flame reactions or don’t.

For future SI engines, it is required to design a carbon-neutral fuel which could improve both combustion stability and antiknocking property extremely for super leanburn with very-high compression ratios. Research octane number, RON, is an antiknocking index. The RON of a liquid hydrocarbon blend can be estimated by the blending rule using the RON's of elements. In the present study, isooctane/normal heptane blends and toluene/normal heptane blends with the same RON's but different LTO appearances have been experimented for their knocking limits of SI engine operation. The LTO of an isooctane/normal heptane blend is stronger than that of the toluene/normal heptane blend with the same RON. For the RON of less than 95, which shows observable heat release from LTO, the knocking limit of a toluene/normal heptane blend advances from that of the isooctane/normal heptane blend with the same RON. For the RON of more than 95, on the other hand, the knocking limit of an isooctane/normal heptane blend advances from that of the toluene/normal heptane blend with the same RON.

Generally, when flow in a pump impeller is recorded by a high-speed video camera, the fluid flow between the blades is recorded at a high absolute velocity. Therefore, accurate measurement of flow conditions not only requires an ultra-high-speed camera and a high-power light source, but also complex secondary processing to convert absolute velocity to relative velocity. To overcome this problem, a relative still recording system for rotating object was developed that takes advantage of the characteristics of dove prism. In this report, this recording system was applied to a submersible pump to capture the flow conditions inside the pump and succeeded in capturing the details of cavitation that occurs between the blades.

Periodic vortex pairs emitted from the upper and lower surfaces of a square rod in the laminar flow of a two-dimensional channel may reverse their vertical positions as they flow downstream. The conditions for the occurrence of this crisscrossing motion are determined by the Reynolds number and blockage ratio of the flow. In this study, the conditions under which crisscrossing motion is observed both in a two-dimensional channel flow and in a rectangular duct flow having side walls were investigated. In the duct flow, the mechanism of the occurrence of crisscrossing motion was investigated based on the three-dimensional vortex structure. As a result, although cross motion occurs in a rectangular duct, its location changes depending on the span direction position. It was found that there are positions where no crossing motion occurs. It was also found that the local heat transfer coefficient distribution is affected by the three-dimensionality of the flow, and although 40% in the center of the flow path is two-dimensional, the distribution is influenced by the three-dimensionality of the flow over a wide area on the side wall side.

Recently, more and more researchers and industrial practitioners have begun to pay attention to dual-arm robots, not only because they provide more maneuverability in the field of automation, but also because of the convenience they bring to machining. Based on this, we believe it is necessary to investigate how to synchronize and accurately control the dual arms during machining. In this paper, we propose two methods for direct control of a plate by the dual arms of a robot to make a ball placed on the plate show predictable motion, and analyze the actual and ideal motion trajectories of the ball. The objective is to verify the accuracy of the control by comparing the motion trajectories. It was found that the motion trajectories were somewhat in line with expectations and the control system is accurate.