The present review paper focuses on the recent works in studying the flows around a circular cylinder and a teardrop shaped model for the Reynolds numbers in the respective critical transition ranges, which are featured with the development of laminar separation bubbles on the contour surfaces. Particular attention was paid to the flow phenomena associated with the unsteadiness of laminar separation bubble(s), which appeared to have significant impact on the aerodynamic characteristics in this flow regime.

In the mercury target for the pulsed neutron source, cavitation is a critical issue to realize a stable and high-power operation of the system, since the cavitation causes severe erosion damage on the mercury enclosure vessel. We have introduced following two techniques to mitigate the cavitation damage. One is the gas microbubbles injection into the flowing mercury, and the other is the double-walled structure with a narrow gap channel at the front part of the vessel. The double-walled structure is expected to mitigate the cavitation damage due to the pressure gradient produced by high-speed flow (~4 m/s) and the narrow gap boundary (2 mm). To quantitatively investigate the effect of double-walled structure on cavitation damage, cavitation damage tests were conducted by parametrically changing the mercury flow velocity in narrow channel and the channel gap width. The results showed that the damage was reduced by increasing the flow velocity whereas the gap width dependency on damage in the range between 1.5 and 2.5 mm was hardly observed under flowing. Experimental results suggested that the damage mitigation effect by high-speed flow was more dominant than that by narrow gap in double-walled structure.

A novel method to fabricate closed-cell porous metals from low melting point alloys is developed by blowing microbubbles into the molten metal using an ultrasonic bubble generator. As it does not require additional materials such as thickener or foaming agents, the developed method is simpler and more economical than conventional methods. The fabrication setup consists of a gas supply system, a temperature regulator, and a microbubble generator; the ultrasonic waves of the microbubble generator break the gas injected to the molten metal through the tip of a hollow horn down into microbubbles. Their low buoyancy causes the generated microbubbles to remain in the molten metal until they are solidified during cooling. Furthermore, the formation of foams during the process resulted in a closed-cell structure. The porosity of the closed-cell porous metal fabricated in this study was found to be greater than 70%. Moreover, the porous metal which can be fabricated has micropores. This technology makes it possible to fabricate porous metals more economically and simply than conventional methods, and if mass production is possible, it is an innovative method.

We measure the two-dimensional vorticity field, drag and lift forces around a NACA0012 airfoil in a periodic flow with a sinusoidal velocity profile in the mainstream direction. An angle of attack of the airfoil is changed in the range of 0 to 60 deg in increments of 5 deg. The two-dimensional velocity field is measured by particle image velocimetry (PIV). These measurements of the velocity field and hydrodynamic forces are conducted simultaneously. For comparison, a similar experiment is carried out in a steady flow that the averaged mainstream velocity is the same as that of a periodic flow condition for Reynolds number R_e=3.8 x 10³ and reduced frequency k=3.98. We have found that the maximum value of the lift-to-drag ratio in a periodic flow is rather larger than that in a steady flow.

A liquid mercury target for the pulsed spallation neutron source has been in operation in the Japan Proton Accelerator Research Complex (J-PARC). Liquid mercury enclosure vessel made of stainless steel is damaged by the cavitation erosion induced by pressure waves that are generated by proton beam injection. A double-walled structure with a narrow channel in front of the mercury target vessel was adopted to the vessel for expecting to mitigate cavitation damage. In this study, we at first made clear of the mechanism of cavitation damage mitigation in narrow channel through visualizing the growing and collapsing behaviors of the spark-induced cavitation bubbles under flow field using a high-speed video camera. Furthermore, we measured the wall vibration due to the cavitation bubble collapse with parametrically changing flow velocity. While the microjet without flow collides perpendicularly with the wall, the microjet with flow collides with an inclined angle from the perpendicular. As the results, the collision pressure was found to be mitigated by flowing effect.

In a dual fluidized bed gasifier, steam is used as a gasifying agent for gasifying a fuel. The amount of steam may be changed by the gasifier’s operating conditions. The characteristics of the tar components by the change of supplied steam in the gasifier are very important in the design of the tar treatment of the gasification system. In this study, the behavior of tar components in a practical steam gasification conditions of lignite were clarified. A gasification experiment was conducted by changing the amount of steam at 1123 K using a laboratory-scale fluidized bed gasifier. As the results, by an analytical method combining gas chromatograph mass spectrometry and the field desorption mass spectrometry, the main component of tar was found to be polycyclic aromatic hydrocarbons, independent of the change of supplied steam in the gasifier.

Volatile organic compounds (VOCs) released by paint are one cause of air pollution and human sickness. The spray coating method is often used when coating large areas such as vehicle bodywork and buildings. Although the relationship between spray characteristics and coated surface quality is clearly important, few investigations can be found in the literature. In this study, the droplet adhesion behavior when spray coating a wall surface was investigated experimentally. The characteristics of the paint film formed by the spray droplets were visualized, and the paint film thickness was measured using a fluorescence method to investigate the smoothing mechanism. Images of the coated surface recorded using a digital microscope were binarized to measure the ratio of coated area to uncoated area. At the start of the coating process, the ratio of coating area increased linearly with time and then the rate began to decrease. Coating was completed sooner when using a higher injection pressure. From the data of the coated area, the ratio of overlapping paint was also calculated, which can be used as an indication of excessive paint and became 350% at the maximum injection pressure used in this study.

Experimental investigations have been carried out on the fluid flow and heat transfer of natural convection induced in a horizontal circular slot. The circular slot confined with two circular disks of equal diameter, where the lower disk is heated with uniform temperature and the upper disk is insulated. Water was adopted as a working fluid. The diameter D and the gap between two disks H were varied systematically as, D = 50-250 mm, and H = 10-50 mm, ∞ (without upper disk). The flow fields were first visualized with dye. The results depicted that the following flows appear in the circular slots. A laminar boundary layer develops over the lower disk near the outer periphery of the slot. Then, the boundary layer separates threedimensionally from the surface of the lower disk, and the streaky flow appears downstream the separation, and a turbulent flow is attained near the center of the slot. It was found that the onset of the separation over the lower disk shifts to the outer periphery of the slot, and that the radial-pitches of the separation are decreased significantly with decreasing the gap H. The overall Nusselt numbers of the heated lower disk were subsequently measured. The results showed that the Nusselt numbers remain identical as those without the upper disk when the gap H is large enough. However, the numbers decrease significantly with decreasing H, in particular, when the diameter of the disk D is large.

In the present paper, the mixing performance of a 3D lab-on-a-chip device, which is used for small immunoassay systems for medical diagnosis and environmental analysis such as enzyme-linked immunosorbent assay (ELISA), was investigated by using 3D fluid dynamics simulation and design of experiment (DOE) to optimize the micro channel structure. The degree of mixing was calculated by a three-dimensional finite element analysis code “Fluent” applying k-ε model, which is a typical turbulence model, changing design parameters (temperature, angle, flow rate, viscosity, length, hole diameter, degree of overlap). 18 sets of conditions determined by DOE were conducted. As a result, it was found that the effective parameters for promoting the mixing were half-cross structure, smaller tilt angle and higher viscosity, probably due to enhancement of shear stress in the fluid. Furthermore, in the newly suggested structures “half-cross” and “improved halfcross”, the degrees of mixing were improved to 40% and 60% respectively, in comparison to the conventional mixing structures of “straight” and “full cross” which showed the degrees of mixing of 10% and 25% respectively.

An economical and technical solution in heat storage is a key point for the reduction of power generation cost of the CSP plants. A TES (thermal energy storage) system which uses the air as HTF (heat transfer fluid) and a packed bed of stone as the storage material have been developed in the previous study. This paper describes the experimental and CFD study on a TES system with packed-bed of stone using high-temperature air as HTF to be hybridized with CL-CSP(Cross Liner-CSP), which is an innovative solar concentration system newly proposed by Tokyo Tech. The numerical simulation is performed using commercial CFD software ANSYS Fluent and the validation is performed using a pilot-scale TES model. The influencing factors which affect the thermal stratification, such as the tank height-to-diameter ratio, the different stone size and the mass flow rate, are taken into consideration. As a result, the CFD simulation and experimental investigation show good agreement. The thickness of the thermocline is discussed for the CFD simulation result to evaluate the performance of a TES tank.

Dissolved oxygen in liquids plays an important role in a variety of fields such as materials engineering. For example, the dissolution rate of oxygen into a molten metal bath is responsible for the efficiency of decarburization in the steelmaking industry. Oxygen is commonly introduced into the bath using many kinds of injection devices. The dynamic behavior of oxygen bubbles mainly governs the oxygen dissolution rate. Water model experiments were carried out in a previous study to understand the oxygen bubble behavior and dissolution rate for basic three (bottom, side, and top) gas injection systems. The side gas injection was found to be most effective for oxygen dissolution. This is probably because the oxygen dissolution rate is closely associated with the length of bubble dispersion region in the bath. In this study air was injected horizontally into a cylindrical water bath through an immersed L-shaped lance. The dispersion pattern of bubbles and related bath surface oscillations were observed with a high-speed video camera and a still camera. An empirical equation was proposed for the length of bubble dispersion region, L_BS, based on the data on L_BS measured in this study.

In this study, drop-weight impact tests were performed for honeycomb sandwich panel specimens with various impact energies. In addition, damage growth simulations of the honeycomb sandwich panel were performed considering Coulomb friction, surface-based cohesive behavior, and continuum damage dynamics in order for simulating fixing specimen with jig, plastic deformation of faceplate, faceplate/adhesive-layer interface failure, adhesive layer failure, and honeycomb failure. Specimen failure morphology such as damage and debonding, indent depth, and load-time curve (load history) obtained from impact tests are compared with simulating results. The present numerical model shows good agreement with experimental results in terms of above comparisons. This study mainly presents modeling procedure for this high-fidelity simulation for drop-weight tests.

Since an Al/Ni multilayer powder developed by a repetitive cold rolling and pulverizing method shows controllable instantaneous self-propagating exothermic reaction, it is expected that the Al/Ni multilayer powder can be used as a heat source for the solder joining procedure. To evaluate the validity of the instantaneous solder joining technique using the exothermic heat, solder joining experiments using Cu wire specimens were performed. Based on the experimental results, we investigated an influence of an additional amount of the Al/Ni multilayer powder on the electrical and mechanical properties of the solder joining part. As a result, in the limited optimum amount of the Al/Ni multilayer powder, we successfully obtained the expected solder joining parts involving relatively lower electrical resistance and higher strength. In contrast, the fracture strength decreases with increasing the additional amount of the Al/Ni multilayer powder caused by a generation of lots of huge voids in the solder layer due to overheating. In summary, it is likely that the instantaneous solder joining technique using the Al/Ni multilayer powder enable us to be utilized by the optimum additional amount of the Al/Ni multilayer powder.

The influence of load frequency on a cyclic stress measurement method using electrodeposited copper foil is investigated in this study. The copper foil is obtained by electroplating, and the foil is adhered onto the surface of a plate-type specimen made from carbon tool steel. After cyclic loading tests are performed at three different load frequencies, the densities of grown grains occurring in the copper foil are measured using an optical microscope and an image processing software. The experimental results reveal that the strain sensitivity of the grain growth tended to increase slightly with decreasing load frequency. When the difference in the load frequency is about two times, the influence of frequency on the grain growth density is small. On the other hand, when the difference reaches about ten times, a measurement error of about 10% occurs. Therefore, it became clear that it is necessary to consider the influence of load frequency in order to measure stress more accurately. In this study, the conventional calibration equation for stress measurement based on the grain growth density was modified to a new expression that takes into consideration the influence of load frequency.

This paper describes an estimation of elastic and plastic properties of Poly (9-vinylcarbazole) (PVK) and 4, 4’Bis (N-carbazolyl)-1, 1’-biphenyl (CBP) thin films by using a nano-indenter. PVK and CBP were coated in a thickness of 350-500 nm on a glass substrate for Organic Light Emitting Diode (OLED) devices by spin coating and vacuum deposition respectively. The measurement of Young’s modulus was carried out by the continuous indentation method. Plastic deformation properties were obtained by a method proposed by Higuchi et al. (2009) and Ogasawara et al. (2007), that is stress-strain curve is estimated in an equation of σ= Rεⁿ . The results have shown that the elastic modules of PVK and CBP were 9.3 MPa and 9.5 MPa respectively, which are a little lower than those of Alq₃ and α-NPD reported in the previous paper. Further, the material constant n are 0.003 and 0.0007 for PVK and CBP respectively, which are much smaller than those of Alq₃ and α-NPD, suggesting that PVK and CBP have nearly elastic-perfect plastic properties. Therefore, it has been suggested that the reason why PVK and CBP thin films showed higher critical cracking strains more than 7% is resulted from the lower elastic modulus and the smaller work hardening rate (n) than those of Alq₃ and α-NPD whose critical cracking strains are 5.0 % and 3.6% respectively.

This paper proposes a method for identifying the coefficient of thermal expansion of dissimilar materials that are simulating electronic packaging. Mismatch of the coefficient of thermal expansion in a substrate structure is simulated using dissimilar materials with silver solder composed two kinds of metals. The displacement distribution under a uniform thermal load is measured using digital image correlation and the coefficient of thermal expansion is obtained by performing inverse analysis from the measured displacement result as an input. The virtual fields method based on the principle of virtual work is employed as the method for the inverse analysis. Each coefficient of thermal expansion that is an unknown parameter is determined by preparing the virtual displacements as many as the number of materials in the structure. The effectiveness of the inverse analysis method is demonstrated by identifying the coefficients of thermal expansion of dissimilar materials. Results show that the coefficient of thermal expansion can be obtained by the proposed method.

Solidification structures and casting soundness of multilayer Al-Si alloy pipes produced by a two-step centrifugal casting process have been investigated. Two kinds of molten metals, i.e., the first melt (Al-12mass%Si or Al-14mass%Si alloy) and the second melt (Al-32mass%Si-0.1mass%P alloy) having a higher liquidus temperature were cast in sequence into a vertical centrifugal caster. The second melt was cast after the solidified shell of the first melt had grown partway from the contact surface with the mold. The cast pipe specimens were typically composed of three layers. The outer layer was the surviving part of the solidified shell of the first melt after contact with the second melt cast at a high temperature. The intermediate layer was derived from the molten or partially-molten part of the first melt. The inner layer had a hypereutectic structure containing fine primary silicon crystals originated in the second melt. The integrated length of crack-like defects at the boundary between the intermediate and inner layers varied depending on the growth degree and structure of the solidified shell of the first melt.

Critical cracking strain of transparent conductive polymer thin films, aluminum and silver alloy thin films on polymer thin films prepared on a flexible polyethylene naphthalate (PEN) substrate was investigated by applying tensile strain to the specimens with monitoring the electric resistance of the thin films. The final target of the present research is the improvement of flexibility of organic devices, flexible displays and flexible organic light emitting diodes (OLEDs). As a result, it was found that transparent conductive polymer PEDOT: PSS films do not cause cracking and the electric resistance increased theoretically by around 10% of strain. Regarding the two layer thin films, cracking initiated at a strain of around 4% then the electric resistance started increasing. The reason has suggested that cracking was caused by the strain resulting in cracking with forming network shape. Furthermore it was found that the aspect of the cracking depends on the under-layers suggesting the effect of ductility and adhesion of the films.

Japanese folding fans were born during the Heian period (794 -1185) and had been used in various situations. Many of the fans in the Edo era (1603-1868) had become sophisticated by the processing technique of “natural materials” and its application to “artistic originality”. For the technological and the reproduction, it is important that the investing and the consideration from viewpoint of description which arises by folding configuration of “Folding Fan”. In this study, multidimensional measurement of closed and opened shape of folding fan was carried out for the quantitative evaluation and the re-verification and the revaluation over looked in the past researches of “Folding Fan” become possible.

The camera parameters of each camera must be determined to demand the three-dimensional coordinate of the object in image from a stereo image. The determination of the camera parameters is the most important calibration work for a highly precise measurement. The determination of eleven linear camera parameters needs the information of more than six points of the coordinates in space (x, y, z) and the corresponding camera screen projection coordinate (X, Y). The set of those six points must include three-dimensional structural information (six points must not on same plane). In this research, a theoretical method to determine eleven camera parameters from four points of information in the plane and focal length of the camera lens is developed.

When designing the shape of a product that is comfortable to grasp, a quantitative evaluation that can be performed in a short-time and at low-cost is required. In this study, we developed a hand finite element model and a grasping simulation method to simulate the grasping motion of a volunteer and to reproduce the contact pressure distribution on the palm during grasping experiment against a cylindrical object. Furthermore, a parametric study was also conducted to investigate the effect of several factors on the contact pressure distribution. It was found that the contact pressure tends to increase overall with the decrease of the hand size. This trend was similar to the case, where the contact pressure increases with the increase of the diameter of the cylindrical object. Furthermore, large contact pressure concentration was confirmed when the Young's modulus of the cylindrical object increased. On the other hand, the influence of the friction coefficient on the contact pressure distribution was relatively small compared to other factors.

Bone fracture injury frequently occurs in various accidents. During an accident, bone may be subjected to a single load or combination of multiple loads, e.g. tension, compression and shear. In this study, we conducted tension, compression and shear tests on bone tissue specimens in order to obtain the mechanical and failure characteristics of cortical bone tissue. Bone specimens were obtained from bovine femur. Haversian bone part of the femur was utilized to manufacture three kinds of specimens for tested in tension, compression and shear tests. The tests were conducted using a table-top universal testing machine equipped with custom-made jigs under a displacement rate of 1 mm/min. From the test result, load-displacement curves and stress-strain curves could be derived. Variations in the curves were confirmed. There were also notable differences in the elastic moduli and failure points. The failure strength of bone tissue was considered to be dependent on the loading modes. Collagen fiber was considered to have a strong resistance against tension, whereas hydroxyapatite was considered to have a strong resistance against compression. In addition, the direction of load against femoral axis was also found to have influences on the elastic modulus and failure point. The orientation of collagen fibers in the specimens was considered to be a factor that caused the differences.

The medial collateral ligament (MCL) of the knee is the primary static stabilizer against valgus rotation of the knee and a secondary restraint to anterior tibial translation. In previous studies, stiffness of the MCL was described using length change data under both in vivo and in vitro conditions. This study aimed to describe a direct method to measure the stiffness of the MCL over a range of knee flexion angles using strain ultrasound elastography. Ten healthy males were included. Strain elastography with an acoustic coupler as the reference material was used to obtain relative stiffness of the proximal, middle, and distal portions of the superficial MCL and the meniscofemoral and meniscotibial components of the deep MCL while placing the knees in flexion at angles of 0°, 30°, 60°, 90°, and 120°. The results of this study ensured good measurement reliability with good to excellent intrarater and interrater agreements. The relative stiffness of the MCL was greater during low flexion angles, and the ligament was relaxed when the knee flexion angle increased. Strain elastography with an acoustic coupler is a feasible and reliable method to assess the relative stiffness of the MCL.

Understanding cell-to-cell and cell-to-substrate adhesion forces is useful for the reproducible cultivation and detection of defective cells. In this study, the relationship between tensile pressure and the signal from a bonded-layer sensor was determined. We have developed a thin and flexible sensor film for measurement of force between contact interfaces that consists of a layer of pressure-sensitive material placed between two electrodes. When the layers are bonded, the sensor can be used to measure tensile force. The electrodes were fabricated from flexible copper-polyimide laminated film by photolithography and a wet-etching process, and a pressure-sensitive rubber layer was inserted between the electrodes and bonded to them with silver paste. Calibration tests were performed using a universal testing system with an affixed load cell for accurate force measurement. Tensile pressure was measured with the sensor, and the resolution of pressure detection was below the sub-kPa level.

The purpose of this study was to propose a method of measuring the dynamic characteristics of the quadriceps muscle-loaded patellar tendon using cine magnetic resonance imaging (MRI). Five knees were imaged with 3D T1-weighted scans at rest and multi-slice 2D cine T1-weighted scans during knee flexion and extension. 2D cine images were acquired for 2 minutes, about every 1 second during active knee motion. Image registration based on 2D cine images was done with 3D reconstruction images using the transformation matrix from 3D images for the femur, tibia, and patella. The inverse matrix was defined as a transformation matrix that represented the motions of each bone. It was confirmed that the patellar tendon was in tension in 2D cine images, and the length of the patellar tendon was defined as the direct distance between each insertion site using 3D images. The length of the patellar tendon increased with knee extension, although previous studies during standing and prone positions had a tendency to stretch along with knee flexion. This difference in the length pattern of the patellar tendon was caused by the tensional force of the quadriceps muscle.

In this study, we fabricated two types of stand-assist chairs with different rising trajectories of the seating surface in order to reduce the burden on the user’s body when standing up from them. Then, we analyzed their resulting burden exerted when performing the upright motion. We experimentally examined the two types of chairs and compared them with an additional ordinary one. We analyzed the joint torque using a digital manikin using motion simulation software and measured the muscle activity through electromyography to evaluate the standing load by focusing on the difference in the movement characteristics between standing and upright motions. The knee joint torque associated with the proposed stand-assist chair was about 50% less than that for the ordinary one when the body was heavily loaded during the standing motion. In addition, in that case, the activity of each muscle (erector spinae muscles, vastus medialis muscle, and vastus lateralis muscle) showed the most significant decrease with the downward-arc stand-assist chair.

A chair with the power assistance function was developed by a Japanese company for training and rehabilitation of aged person. Developers aimed to help aged person to stand up easily without other person's support. However, its effect of the function is not yet sufficiently evaluated. To evaluate the power assistance function of the chair, it is important to measure user's motion and change of muscle force. The power assistance function of the chair can be produced by using commercial parts of frame structure. The assist function of this chair is evaluated to design the optimum mechanism that provides effective support. So, the motion of user and assist mechanism of the chair were measured by using motion capture system in this study, and the muscle force was evaluated by acquisition of myoelectric signal at the same time. The experiment was executed by using a chair with the assistance function and a chair with no assistance function in the case of standing up and sitting down motions.As results, the relation between the behavior of test subject and the seat motion of the assistance chair was clarified by motion capture, and the muscle force of test subject were obtained by myoelectric signal. By means of simultaneous measurement of motion and myoelectric signal, the muscle activity against the timing of motion was well understood.

Prescription of a plastic ankle foot orthosis (PAFO) is currently based on the experience and intuition of the doctor. A systematic approach is necessary to establish prescription standards. In this study, we analyzed the mechanical load acting on PAFOs during the stance phase of walking using our previously developed measurement system. In addition, these values were compared between 5 healthy volunteers and 7 patients with hemiplegia. Large differences were observed in the knee joint angle from 70% to 100% gait cycle, which increased steeply to about 40° in the healthy volunteers but increased gradually to about 20° in the hemiplegic patients. Also, the maximum angle of the knee joint in the healthy volunteers was 1.26 times greater than that in the patients, while the minimum angle of the knee joint was 0.84 times smaller. The amount of deformation of the PAFO was about 1.87 times greater at the knee joint and about 1.31 times greater at the ankle joint in the healthy volunteers than in the hemiplegic patients. These results revealed differences in the mechanical load between healthy volunteers and hemiplegic patients that affected the PAFO in terms of the ankle joint and knee joint during stance phase.

To recycle silica byproducts and to moderate the heat-island phenomenon, a porous ceramic was prepared by mixing waste silica powder with clay and then firing the resulting mixture. Following this, by exploiting the high waterabsorption capacity of the ceramic, a greening material, where the ceramic sample was covered with moss, was produced. To examine the ability of the moss-covered sample to suppress the temperature increase caused by solar-radiant heat, as well as to investigate the influence of water content on the sample temperature, the surface-temperature change of the sample during solar-radiant heat reception and the amount of water evaporated from the sample were measured simultaneously. Further, to verify whether the moss-covered sample could reduce the heat flow into a room, the heat flux between the rear surface of the sample and the rooftop floor of a test structure was measured. The experimental results confirmed that a moss-covered sample that could absorb sufficient water could suppress the temperature increase caused by solar-radiant heat over the entire day and significantly reduce the heat flow between the rear surface of the sample and the rooftop floor.

A series of experiments including unconfined compression, permeability, and durability tests were performed to evaluate and compare the effect of different fiber materials on cemented sludge under the same mixing condition. The used fiber materials in the present work consisted of rice straw, corn silk, rice husk, and paper debris. The results showed that fiber materials improved compressive strength, anti-seepage capacity, and durability of cemented sludge. Namely, compressive strength of cemented sludge was improved from 70.4 kPa to 157.3 kPa, 180.8 kPa, and 228.1 kPa with respect to the addition of paper debris, corn silk, and rice straw. Nevertheless, the results of specimens reinforced by rice husk changed slightly as compared to that of cemented sludge in term of compressive strength. The addition of fiber materials decreased the hydraulic conductivity of cemented sludge from 22% to 73%. Besides, with rice straw, corn silk, and paper debris inclusion, specimens could survive after 10 cycles of drying and wetting, meanwhile, cemented sludge and rice husk reinforced cemented sludge were destroyed in the first cycle and fourth cycle, respectively.

The present paper discusses the peak wind force coefficients for designing the claddings and its immediately supporting structures of open type membrane structures based on a wind tunnel experiment. Three types of gable-end configurations, i.e. enclosed, open and partially-enclosed (semi-open) types are tested. The wind tunnel experiment is carried out in two kinds of turbulent boundary layers corresponding to open-country and urban terrains. The wind pressures are measured simultaneously at many points both on the external and internal surfaces. First, the distributions of mean wind force coefficients are investigated to understand the characteristics of the wind forces, focusing on the effects of gable wall configuration. Then, the maximum and minimum peak wind force coefficients irrespective of wind direction are examined. Furthermore, the characteristics of internal pressures on open and semi-open type structures are investigated. Based on the results, an estimation method for evaluating the peak wind force coefficients for open and semi-open type structures is proposed.

The average temperature in Japan has become higher in recent years owing to global warming and the urban heat island. Many people suffer from heat strokes during summer. Therefore, measures must be taken to ease the summer heat. In this study, we tested a procedure during the summer of 2014 and 2015 aimed at ameliorating the adverse effects of the summer heat by planting trees in containers and installing mist sprays. We measured the air temperature, wet-bulb globe temperature (WBGT), solar radiation, and other such indicators of the atmospheric temperature in three areas: (1) townstreet, (2) tree planting, and (3) tree planting with water spray areas. The globe temperature could decrease by 3 °C in the tree planting area and 7 °C in the tree planting with water spray area. Further, based on the WBGT, which was used as a guideline for the prediction of the risk of heat stroke, the time ratio judged as “extremely hazardous” decreased from 42.9% to 20.7% of the total measurement time, thereby confirming that the trees and water spray greatly facilitate heat stroke prevention.

This paper presents the findings of a study carried out on the characteristics of sound generated by a snare drum using the coupled mode analysis of the vibrations of the upper membrane and far-field sound with extended proper orthogonal decomposition (POD). Experiments were conducted by employing two players with strikingly different degrees of proficiency to ensure that the impact of the beating technique on the sound generated could be captured. While one player had more than seven years of experience, the other had hardly any experience. Analysis of the results revealed that the first mode of the vibrational acceleration of the membrane caused the most intense sound for both players. However, the sound corresponding to the first mode decayed relatively faster in the case of the experienced player because, unlike the inexperienced one, he did not beat the drum very close to its center, and his beating was relatively quicker. It was also found that the striking stick and the snare-wire play important roles in emphasizing and complicating the vibrational mode of the membrane for sound generation, respectively.