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In the present report, we focused on high reduction ratio hypoid gear with a three-tooth pinion and its meshing performance. First, we monitored the tooth surface temperature in meshing teeth, based on combined image from temperature images with a high-speed-camera thermography, and compared it with tooth contact image with a red paint. Moreover, we proposed a predicting method of tooth contact area from a combined temperature image on the tooth surface. Second, we estimated its real contact ratio based on measuring the tooth root stresses at the toe, middle and heel positions. Third, we measured the meshing transmission error (MTE) between the gear and the pinion, and the rotational acceleration at the gear outer in meshing teeth. As a result, it could be seen that the real contact ratio affected tooth surface temperature and MTE. Regarding a high reduction ratio hypoid gear, the deformation at the gear rim also affected the dynamic vibration in meshing gear and pinion teeth.

The authors have developed and built a new system which could achieve carbon neutral of all energy to use at a home including the privately-owned car economically using Photovoltaic Power Generation and Electric Vehicle. The built energy system is managed by an automatic control completely. The effect of the system has been verified the demonstration experiment through real life for more than one year. As the result, CO2 emissions from home was reduced more than 90%. [ABSTRACT FROM AUTHOR]

It is important to estimate the strength of the vehicle structure in the initial design stage of the vehicle development. The buckling of the plate is known to occurs in thin-walled structures before yielding, however, the structures can withstand loads even after buckling. The load acting on the thin-walled beam constituting the vehicle frameworks may be not only a compressive force and a bending moment but also a torsional torque. The purpose of this paper is to derive the equation for the torsional post-buckling behavior of a thin-walled square cross-section beam. When a torsional torque acts on a square cross-section beam, in-plane shear stress acts on the four plates constituting the cross section, which may cause shear buckling. Assuming that the same buckling deformation occurs on the four plates, Timoshenko's approximate expression can be applied as an out-of-plane displacement after shear buckling. The post-buckling stress distributions are calculated as a function of the out-of-plane displacement amplitude. Also, the post-buckling torsional constant and relationships between the torsional torque and the stresses are derived on the basis of Karman's effective width theory. The validity of derived expressions is examined by comparing with the computation results by the finite element method (FEM). As a result, in the target dimensional range of the plate (width-to-length ratio 1/3 or less), the absolute difference values of the derived relationship between the torsional torque and the maximum Mises stress are within 10% for FEM results. However, it is found that instable phenomena such as secondary buckling may occur as the width-to-length ratio of the plate becomes smaller. From the above results, it is found that the relational expression derived in this paper is sufficiently useful for calculating the torsional strength of a thin-walled square cross-section beam.

In this study, we researched correlations between the joint moments and the variables obtained from the experimental data to estimate the driver's joint moments in order to simulate the driver's behavior during turning considering the driver's intention when riding on a stand-up type Personal Mobility Vehicle (PMV). First, we measured human behavior, handle reaction force, and floor reaction force using motion capture, 6-axis force sensor, reaction force meter attached to the foot. From the obtained external forces and human behavior, the driver’s joint moments were calculated using inverse kinematic analysis and inverse dynamic analysis. The loads on the joints during the turn was examined, and it was found that the loads were greater in the shoulder, hip and ankle joints. Therefore, correlations such as external forces, vehicle velocity, and joint angle to the joint moments of the shoulder, hip, and ankle joints were investigated. As a result, it was found that the correlation with external force was high. Accordingly, the joint moments of the shoulder, hip and ankle joints were estimated by linear multiple regression analysis using the external force. The joint moments of the shoulder and ankle joints were estimated with good accuracy, but those of the hip joint were inaccurate. From these results, it can be interpreted that the joint moments of the shoulder and ankle joints depend on the external force applied to the hands and feet.

In very high cycle fatigue for high strength steels, one can usually observe the fish-eye on the fracture surface and an inclusion is observed at the center of the fish-eye. The fine granular area (FGA) is also found in the vicinity around the inclusion at the crack initiation site on the fracture surface. If the stress cycles required to form the FGA occupies the predominant part of the final fatigue life of these steels, the FGA formation mechanism is one of the most important subjects in the very high cycle fatigue. From this point of view, the authors have attempted to construct the FGA formation model based on the current experimental results obtained by the authors. Supposing four different probabilistic models, the FGA formation is interpreted as intermittent micro-debondings and their coalescence during the long sequence of the cyclic loadings. After the FGA was accomplished, the penny-shape crack tends to grow steadily following the well-known Paris’ law. Based on this analysis of the FGA formation, it was found that polygonization around the inclusion is more important behavior to govern the total fatigue life of the high strength steels.

Lecanemab is a humanized monoclonal antibody directed against human soluble amyloid-β aggregates. It was developed for the treatment of early Alzheimer's disease (mild cognitive impairment or mild dementia stage of Alzheimer's disease). Among the amyloid-β (Aβ) involved in Alzheimer's disease, Lecanemab selectively binds to the highly neurotoxic Aβ protofibrils, and is thought to reduce Aβ protofibrils and amyloid plaques (Aβ plaques) in the brain. The efficacy and safety of Lecanemab in early Alzheimer's disease were investigated in an international Phase II placebo-controlled study (Study 201) and an international Phase III placebo-controlled study (Study 301). Both studies included Japanese subjects. Lecanemab was given accelerated approval in the United States in January 2023, followed by traditional approval in July 2023. In Japan, it was approved for "control of the progression of mild cognitive impairment or mild dementia stage of Alzheimer's disease" in September 2023, and was added to the NHI drug price list in December 2023. [ABSTRACT FROM AUTHOR]

A 72-year-old woman was found by colonoscopy to have transverse colon cancer. She had a history of open total gastrectomy with ante-colic Roux-en-Y reconstruction for gastric cancer. We performed a laparoscopic extended right hemicolectomy. Intraoperatively, the tumor was located on the right-sided transverse colon. In order to keep a sufficient distal margin, it was necessary to release adhesions between the reconstructed jejunum and the left-sided transverse colon and mobilize the splenic flexure, while it was necessary to redo the esophago-jejunostomy if ischemic changes were caused by damage to the blood vessels of the reconstructed jejunum. Although we did not keep a sufficient distal margin, we planned to resect the transverse colon located 5 cm on the anal side from the tumor and perform intracorporeal anastomosis, which was end-to-end anastomosis between the ileum and the transverse colon using liner staplers. She was discharged without complications on the 11th postoperative day. Intracorporeal anastomosis has the advantage of requiring minimal mobilization of the colon. In cases of transverse colon cancer after total gastrectomy, we consider that intracorporeal anastomosis is one of the treatment options. [ABSTRACT FROM AUTHOR]

In the present report, we attempt to monitor the temperature of Cu direct laser drilling process of multi-layer printed circuit board with a high speed camera based on two color method and to construct a model of its process with a CFD (computational fluid dynamics). We look at the via-hole drilling using a CO2 laser beam for the FR-4 type insulation layer, which made of glass fiber reinforced epoxy resin plastics, as build-up layer. First, we estimate the temperature distribution at the time line of process including the penetration of Cu layer on the surface and the cooling of drilled hole wall after laser drilling. Second, we discuss a CFD model for the drilling process based on finite volume method. As a result, it can be seen that the monitored results is in good agreement with the calculated ones by CFD model.

As a new means of transportation for short and middle distance, personal mobility vehicle (PMV), which is one or two-seater and has high environmental performance, is recently being developed. It is because many people drive a car when they travel a short distance alone, that is inefficient in cost and space. One of the PMVs which is recently gathering attention is three-wheeled vehicle with leaning mechanism. Leaning mechanism, which gives tires degree of freedom, has an effect of stable cornering in the case of short tread width vehicle. For this reason, this vehicle has two advantages, compact and stability. We research on the vehicle which has two front wheels and one rear wheel. We derived equation of motion by referring to Sharp’s 4 DOF two-wheeled vehicle model, and carried out the numerical analysis to compare three-wheeled vehicle and two wheeled vehicle. However, it’s difficult to find out driver’s sensuous difference between three-wheeled and two-wheeled vehicle by only numerical analysis. Then, we conducted the real-time simulation experiments and questionnaires, search on that difference. Through that experiments, three-wheeled vehicle needs large steering torque and drivers feel sense of security, but steering is difficult when the vehicle speed is fast. On the other hand, two wheeled vehicle needs small steering torque and large output, so drivers steer constantly for maintenance of slalom running.

The car is a main means of transportation all over the world. However, many people drive a car when they travel a short distance alone, that is inefficient in cost and space. Then, personal mobility vehicle (PMV), which is one or two-seater and has high environmental performance, is recently gathering attention. We focus on the three-wheeled vehicle with leaning mechanism called Narrow Tilting Vehicle (NTV) or narrow tilting three-wheeled (NTTW). Leaning mechanism, which gives tires degree of freedom, has an effect of stable cornering in the case of short tread width vehicle. To compere the motion of each leaning mechanism, we model the two types of NTV. One has two front frame which are linked to vehicle body by the arm and rotating respectively around the joint. The other one has a front frame that has two tires connected by the link. We derived equation of motion by referring to Sharp’s 4 DOF two-wheeled vehicle model, and carried out the three kinds of numerical analysis, eigenvalue analysis, modal analysis and running simulation. Through eigenvalue and modal analysis, we find out that NTVs have the same modes as Sharp’s 4 DOF model does, and they have the characteristic mode which vibrates steering and leaning mechanism. By running simulation, NTVs required larger steering torque than two-wheeled vehicle when the vehicle turn at the same angle.

This study has proposed the optimization process regarding the hydraulic transmission installed with construction and agricultural vehicles, in order to contribute to the quietness of the vehicles in which noise from the hydraulic system is expected to become noticeable due to the diversification of power sources. The pressure ripple as the noise source which is derived from the relative motion of pistons, cylinders and valves is non-linear system, and the genetic algorithm which is one of the evolutionary computations is used to search for the optimum solution of design variables. In addition to just search for the optimum solution, the readability of the design space has been obtained by the inductive approach, using many datasets generated in the process of the evolutionary computation. The decision tree, which is one of the techniques in machine learning, is used for the inductive approach and can make the readability of the design space regarding the pressure ripple generated in the hydraulic transmission without the dimensional reduction of the design space and the neglected interaction.

In recent years, PMVs (Personal Mobility Vehicles) have been attracting attention as a new means of transportation. We focus on the three-wheeled PMV which has two front-wheel and one rear-caster. They are environmentally friendly without exhausting harmful gases. These vehicle bodies are relatively smaller than cars, so they have a high affinity for pedestrian space. However, depending on the specifications of the vehicle, there is a possibility that wheel lifts during turning because the weight of the vehicle is low. In this study, we proposed the model of the three-wheeled PMV with two front-wheel and one rear-caster. We discussed the validity of the modeling by comparing the numerical simulation and the experiments. In terms of the driving force of the front wheels, the modeling was generally valid when the velocity of the vehicle is low and the turning radius is large. However, in the opposite case, the centrifugal force of the driver during the turning becomes larger and the moment around the front wheels axle center point is generated. Then it is expected that more detailed analysis will be possible by considering the relationship between the centrifugal force received by the driver and the driving force of the motor in consideration of the driver’s behavior. From the parametric study, it was found that the normal forces of the wheels greatly changed depending on the riding position of the driver. The area of the risk of falling was shown.

In the initial design stage of vehicle development, it is important to estimate the strength of the structure against various loads. It is known that buckling occurs in thin-shell structures before yielding as the load increases, and that the structures can withstand loads even after buckling. The load acting on the beam constituting the vehicle structures may be not only a compressive force and a bending moment but also a torsional torque. Due to this torsion torque, a shear stress acts on the thin shell constituting the beam. In this paper, after shear buckling of a rectangular plate, the approximate expression of buckling deformation presented by Timoshenko as an out-of-plane displacement is used, and the relationship between the out-of-plane displacement amplitude (maximum out-of-plane displacement) and the shear force is determined based on Karman's effective width theory. Using the obtained out-of-plane displacement amplitude, three stress distributions and the maximum value of Mises equivalent stress are derived as a function of shear force. Then, the derived expressions are compared with the computation results of the finite element method (FEM) using shell elements under the boundary condition that does not constrain the in-plane displacement of both sides in the longitudinal direction, and the applicability is examined. As a result, it turned out that the derived relations between the out-of-plane displacement amplitude, the maximum value of Mises stress, and the shear load are less than the absolute value error within 10% in the discussed load range, compared to the FEM computation results. Therefore, the derived expressions are sufficiently effective in determining the yield strength based on the Mises stress.

Chemical reaction near turbulent/non-turbulent (T/NT) interface in liquid phase turbulent flow was investigated experimentally. The concentrations of reactive species near the T/NT interface in a planar liquid jet with a second-order chemical reaction A+B → R was measured with different stoichiometric mixture ratios. The reactants A and B were premixed into the jet and ambient flows, respectively. The optical fiber probe based on the light absorption spectrometry was used to measure the instantaneous concentrations of the reactive species. The T/NT interfaces were separated into two types (i.e. leading edge and trailing edge) and investigated separately. Mean concentration conditioned on the distance from the T/NT interface was calculated. It was found that the thickness where large concentration change of the reactive species occurs are order of Taylor’s microscale and does not depend on stoichiometric mixture ratio. In addition concentration profile of product R near the T/NT interface does not depend on stoichiometric mixture ratio, while equilibrium limit clearly depend on stoichiometric mixture ratio. This means that near the T/NT scalar mixing does not reach molecular level and chemical reaction is not active.

Currently, personal mobility vehicles (PMVs) are attracting attention as intermediate- or short-range transportation. Bicycles are familiar PMVs that are also environmentally friendly and convenient. A small-wheel bicycle saves space and is easy to carry. However, a small-wheel bicycle running at low speed has poor upright stability and maneuverability. The purpose of this study is to improve its running stability by adopting a steer-by-wire system, which independently operates the steering gear and the tire. Sensors obtain the handle angle and actuators, instead of force from a mechanical connection, change the steering wheel angle. In this study, we carried out two experiments. First, we carried out straight running experiments to confirm the steering accuracy, upright stability, and maneuverability on a straight course. Second, we carried out turning experiments to confirm the upright stability and maneuverability on a course requiring changes in driving direction. It was confirmed that the proposed mechanism enhanced the upright stability compared with that of a conventional small-wheel bicycle. However, the maneuverability evaluations by the drivers showed that a conventional small wheel bicycle was better than the proposed steer-by-wire bicycle. The delay of motor control and the moment of inertia of the gearing might be the causes of this performance issue.

In this paper, the equations of in-plane and out-of-plane displacements, in-plane stress distributions, and Mises stress of the rectangular plate after buckling are composed using the well-known buckling deflection shape, based on the plane stress state and the effective width theory by Karman. Equations of in-plane displacement and stress distributions are obtained from the large deflection theory, and the maximum value of out-of- plane displacement is derived by use of Karman’s theory. The composed equations are compared with results of the finite element method (FEM) with shell elements. The boundary condition used in FEM is that the in-plane displacement of both long side edges is unconstrained. As a result, the following conclusions were obtained. Among the composed equations, the out-of-plane displacement amplitude and the in-plane compressive displacement are close enough to FEM computation results. Three in-plane stresses near the both long sides show slightly different distributions between composed equations and FEM results. The normal stress distribution of the FEM result fluctuates near the both long side edges, although that distribution by the composed equation indicates the intermediate value of the FEM result, and it was found that the maximum compressive stress appearing at both sides is lower than the one by the FEM result. On the other hand, the Mises stress distribution and its maximum value were close to the FEM results. As factors of these differences, it is considered that the in-plane deflection of the both sides and the out-of-plane displacement shape at larger load are different from the shape used in this paper.

This work assessed the fundamental characteristics of multifunction cavitation (MFC), that was high-temperature and high-pressure cavitation, through both experimental investigations. The application of ultrasonication to the floating cavitation of a water jet was found to produce microjets containing hot spots. MFC exhibited the capacity to perform nano-level hot work at a material surface, modifying the surface morphology and the surface electrochemical condition by hot spot melting. Ultrasonic irradiation of a water jet during floating cavitation was used to generate microjets with hot spots and this MFC process was employed to perform hot work on CFRP (Carbon Fiber Reinforced Plastics).