The work in this paper aims to investigate the effect of elastic wall on flow characteristics using the numerical simulations and experiments, in which the objective is to investigate the influence of the elastic surface on the flow characteristics around a square-section cylinder at Re=1000. As a result, it is obtained that the elastic surface at the back side of square-section cylinder increases the vortex shedding frequency and reduces the fluid forces around it.

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Cold model experiments are performed to understand the spout eye area in a cylindrical vessel during the bottom gas injection. Low-density particles are used for the model of molten slag and the density of the particles on the spout eye area is investigated. The spout eye area is compared with that of a mercury-silicon oil system. The spout eye area decreases with the density when the thickness of the slag layer is greater than a certain critical value, while remains constant when the thickness is smaller than that critical value.

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A water disinfection treatment approach using ozone microbubbles generated by a hollow ultrasonic horn was developed. This treatment involves efficient disinfection of Escherichia coli. Disinfection of water with and without impurities were dominated by non-selective oxidation by radicals and oxidation by ozone, respectively. This treatment using ozone microbubbles generated by a hollow ultrasonic horn led to efficient disinfection, owing to the high solubility of the microbubbles and synergism of the ozone and ultrasonic irradiation.

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We investigated the effects of the containing gas and gelatin addition on the yield and durability of hollow microcapsules fabricated by the bubble template method. Low-solubility sulfur hexafluoride gas-based hollow microcapsules were smaller-sized and higher in yield than the nitrogen gas-based ones. Moreover, the undamaged hollow microcapsules remaining after a durability test increased after gelatin addition. These results were attributed to the stability of low-solubility bubbles and the reaction promotion of gelatin on encapsulation.

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This study aims to investigate drag reduction of a square prism with cut-corners for nonzero values of the angle of attack α. Selected cutout dimensions are mainly (i) c₁/a = c₂/a = 0.00, (ii) c₁/a = 0.15 and c₂/a = 0.05 and (iii) c₁/a = 0.15 and c₂/a = 0.25. The flow patterns are visualized by using a vortex particle method for Re = 200, and experimentally a hydrogen-bubble (for Re = 4000) and an oil-flow (for Re = 10000) techniques. In addition, the hydrodynamic force on the prism is experimentally measured with either a digital manometer (for pressure coefficient C_p) or a force transducer (for drag and lift coefficients C_D and C_L).Results for some kinds of flow patterns and the measured hydrodynamic coefficients were given with respect to the angle of attack α. Within the present conditions, the cutout dimension of (iii) c₁/a = 0.15 and c₂/a = 0.25 achieves the effective drag reduction in the range 0° α 14° although this dimension unfortunately causes the oscillation of the gallop at about α = 10°.

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Effect of initial unsteadiness on transition to turbulence in constant acceleration pipe flow has been investigated experimentally together with the laminar analytical solution. The acceleration pattern in the present study is a combination of a constant deceleration after the steady regime and then a constant acceleration. Three kinds of the zero velocity period between the constant deceleration and acceleration are selected as (Run 1): 0.0 s, (Run 2): 0.5s, (Run3): 5.0s, and the results are compared with that for a constant acceleration from rest (Run 0). The fully developed axisymmetric Navier-Stokes equations are solved for the present target flow to compare the experimental results before the appearance of turbulence. As a result, the zero velocity period could not distinctly affect transition to turbulence except for t_z = 0.0 s within the present experimental conditions.

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The classical Stokes' paradox for the steady creeping flow past a circular cylinder is theoretically investigated on the basis of the Fredholm integral equations in terms of the vorticity and the stream function. In order to circumvent the difficulty associated with the paradox, this study employs extended Stokes solution that includes the wake behavior behind the cylinder. Then, the present approach successfully determines the indeterminate coefficient caused by Stokes' paradox, and the derived Stokes solution is found to converge to the uniform flow as r → ∞, i. e., Stokes' paradox is resolved.

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Cold model experiments are carried out to determine the number, size, and surface area of slag droplets generated at a slag-metal interface in a cylindrical bath agitated by bottom gas injection. Acrylic monomer is used to represent slag, and water containing salt and gelatin is chosen to represent metal. Since the slag droplets become solid particles after a while due to polymerization, the quantities mentioned above are readily determined by taking them out of the bath and measuring their diameters with screens. As the average power input per unit mass, ε, and the density of the metal increased, the total number of slag droplets, S_p,t, was in proportion to ε, whereas the Sauter mean diameter, d_p32, was inversely proportional to ε. Empirical equations were derived for S_p,t and d_p32. The minimum diameter of slag droplets almost agreed with the diameter of the Kolmogorov micro scale of turbulence.

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In the present research, CARS (Coherent Anti-Stokes Raman Spectroscopy) measurement is applied to find out the characteristics of the non-equilibrium flow behind the strong shock waves generated at hypersonic velocities above 4km/s upto 5.8km/s. The rotational/vibrational temperatures for nitrogen molecules behind these velocities are calculated using the CARS signal obtained by experiments and are compared with the theoretical data obtained by in-house developed fitting program. In the present paper the spatial distribution of ro/vibrational temperatures obtained are presented along with the 2D radiation images captured.

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This paper describes the results of the experimental study on the vibration characteristics of liquid bridge between a solid sphere and a flat solid plate subject to vertical vibration. Experiments were performed on a vibration-testing system. In this experiment, the sample liquid was water, the sample sphere was small aluminium oxide ball, and the sample solid base was the acrylic plastic plate. The dynamic behavior of the solid sphere-liquid bridge system was observed with a high-speed video camera system. It was found that the fundamental responses of the sphere were determined by the excitation acceleration. Capillary adhesion force produced by the surface tension of water was dominant at lower excitation accelerations. The vertical vibration led the sphere-liquid drop system to the chaotic motions at higher excitation accelerations.

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This experimental study is performed to investigate heat transfer performance of a new self-oscillating heat pipe in the condition of different fill charge ratios and different heat fluxes. In this experiment, pure water is employed as the working fluid. The heat pipe is composed of a heating section, a cooling section and an adiabatic section. The heating and cooling sections have the same size and are connected by four circular parallel tubes. The corresponding external dimensions are 45mm in length, 45mm in width and 8mm in thickness, and the internal dimensions are 42mm, 42mm and 5mm, respectively. The adiabatic section is consisted of four parallel circular tubes whose dimension is φ6 (external diameter) x φ5 (internal diameter) x 45 (length) mm. A series of experiments with different fill charge ratios and heat fluxes were carried out to measure temperature of the heat pipe. It is found that heat transfer performance as well as effective thermal conductivity of the heat pipe affected by various operating conditions.

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The purpose of this study is to investigate the dynamic behavior of a pair of spheres with different wettabilities penetrating into a water bath. The visualization technique employs a high-speed camera. An air cavity is formed behind the spheres under certain conditions. The maximum cavity depth and the time required for the cavity to break up are measured and compared with their respective empirical equations proposed previously for a single poorly-wetted sphere. These two quantities can be correlated in terms of the Froude number similitude

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Experimental investigation is carried out to seek an efficient method of enhancing the agitation efficiency in the refining processes agitated by side gas injection. The use of the deep-water type of swirl motion is expected to be promising. The occurrence condition of the deep-water type of swirl motion therefore is determined by visual inspection. Mixing time is measured with an electrical conductivity sensor in the presence and absence of the swirl motion. Empirical equations are proposed for predicting the occurrence condition. The mixing time is found to be independent of the swirl motion under the conditions considered in this study.

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The flow and temperature of UV-curable resin illuminated with UV rays were measured, and it was investigated whether the flow of the resin is related to the heat generated by the chemical reaction in the resin. A system was developed for simultaneously measuring the flow and temperature of the resin using digital and infrared cameras, respectively. The flow was observed as a vector field obtained using a digital image correlation technique. Results indicated that the flow of UV-curable resin in the curing process was mainly related to the shrinkage of the resin and hardly related to its temperature.

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The pyrolysis/steam gasification characteristics of woody biomass were clarified by using a laboratory-scale hot model gasifier. As a result, the amount of H₂ formed by pyrolysis was increased due to the partial cracking by using porous alumina particles as a bed material. Additionally, the amount of H₂ formed was more increased by steam reforming of coke and steam gasification of char in steam gasification. Therefore, porous alumina particles are suitable for more hydrogen production.

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Due to the global energy crises and energy conservation, one of the most important aspects incorporating optimum energy consumption, is the quantitative clarification and the image measurement of the flow fields in convective heat transfer. This paper deals with the quantitative Image Measurement of Natural Convection Using the Color-Stripes Background Oriented Schlieren (CSBOS) Method from a multi heat generating source in the natural atmosphere. Here we have analyzed the temperature gradient by using our originally investigated and developed CSBOS technique and Computed Tomography (CT) method.

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The intrinsically peaceful sound of the water musical instrument derives from the air-bubbles formed by the impact of the water droplets on the water surface. Thus the control of the air-bubbles is the key to the tonal quality. Our study is focused on the influences of the length of the tube sunk under the water surface and water depth on the sound radiated from a water musical instrument. It has been done through the simultaneous measurement of both the generated sound and the process of the formation and collapse of the air-bubbles. When the pipe is immersed deeper in the water, the column of air-bubble becomes longer and the dominant frequency of the sound source based on the bubble vibration is shifted to the lower. And when the water depth becomes shallower, the vibration caused by air bubbles is generated later, and the dominant generated sound is shifted to the higher frequency accordingly.

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The magnetic body force in boiling a two-phase temperature-sensitive magnetic fluid (TSMF) flow is known to effectively increase the driving force of magnetic fluid in a non-uniform magnetic field. Based on this mechanism, in the present study, a binary TSMF, which is a mixture of the TSMF and a low-boiling-saturation-temperature organic solution, is proposed to be used in a heat transport device to enhance its circulation. In order to see its performance in the heat transport device, the pressure difference at different heated temperatures and magnetic fields is investigated experimentally and theoretically when the heating section (test section) positioned horizontally. Results showed that the pressure difference (driving force) increases with both the increase of the axial maximum magnetic field intensity and that of the heated temperature. This was the results of the temperature-dependent magnetization of TSMF and the decrease of the magnetization due to the gas bubble occurrence in the heating region.

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A theoretical and experimental study is conducted to discuss the spontaneous dropping of liquid in a vertical capillary pipe with a lid at the top end. The system energy was calculated when the pipe is inclined to the horizontal direction. The pendant liquid surface formed at the pipe end becomes unstable if the infinitesimal energy change is negative when the three-phase contact line shifts upward on the pipe inner wall. The critical inclination of the pipe is calculated theoretically and the results agree with those obtained experimentally for various kinds of test liquids.

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Disintegration process of aqueous surfactant solutions injected from a fan spray nozzle has been clarified. The thin sheet of the surfactant solution, as represented by soap film, is stable by surface chemical effect and breaks up hard. In this study, this effect on the atomization of the fan liquid sheet has been investigated. Surface chemical stability was evaluated by Ross-Miles method and two types of the test liquids, which had same hydrodynamic physical properties and different surface chemical stability, were prepared. Measured break-up length, which was defined as the distance from the nozzle tip to the end of the liquid sheet, for the two test liquids indicated that the surface chemical stability obviously suppressed the disintegration of the liquid sheet.

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This paper is concerned with the investigation of gas and liquid flow in a rotating cell-porous disc. A simple one dimensional theoretical model of gas flow within the cell-porousrotor and the enhanced model which enables dealing with the gas flow within the porous disc have been proposed. In this study, the flow resistance of rotating porous discs with different pore size was assessed. The residence time of water in the porous disc was measured and the flow resistance was estimated by applying the experimental results to the theoretical model.

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This study proposes a three-dimensional (3D) visualization method that is combined with the hydrogen bubble method (HBM) and digital in-line holography using two-wavelength reconstruction. In this method, the 3D distribution of hydrogen bubbles generated by HBM is measured by digital holography. Vortex shedding from a circular cylinder is observed in an open channel. 3D flow structures of the cylinder wake are successfully visualized.

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The dynamic behavior of a thin-walled circular tube under high-velocity impacts was investigated by performing a finite element analysis (FEA) and an experiment. The FEA for a thin-walled circular tube subjected to an axial impact revealed the effect of the impact velocity. The results suggested that an increase in the initial impact velocity enhances the absorbed energy through compressive deformation. High-velocity impact tests on aluminum alloy circular tubes confirmed the energy absorption characteristics indicated by the FEA.

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The characteristics of absorbed energy for thin-walled circular tubes filled with syntactic epoxy foams subjected to axial compression were investigated in order to develop light weight impact-energy-absorbing structural components. The syntactic epoxy foams with a high volume fraction of micro-balloons were manufactured and used as core materials filling aluminum alloy tubes. Static and dynamic compressive tests of the tube filled with foam suggested that the foam led to higher energy absorption.

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The stress waves at frequency of 5 kHz through the stem of the miniature tomato were transmitted and received to investigate the potential to evaluate the development of vascular tissue of tomato stem by vibration measurement. Two waves were detected and extracted using AE sensor. The wave velocities and the influence of holding a stem on the wave propagation indicated that the detected waves might be the longitudinal and flexural modes. The velocity of detected waves showed strong correlation with the thickness of a vascular tissue rather than a stem diameter. Furthermore, the velocity of the slow wave showed good correlation (correlation coefficient was 0.82) with the parameter calculated from the thickness of a vascular tissue and the stem diameter.

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A flexible tactile sensor has previously been developed for three-axis load measurement using an electrically conductive material and a flexible cylindrical elastic body. The present study attempted to develop a flexible contact sensor capable of measuring a wide range of loads. The diameter of the cylindrical elastic body was fixed at 10 mm, and by changing its aspect ratio from 0.10 to 1.00, the normal load was found to decrease from 132 to 33 N. In addition, the shearing load decreased from 4.2 to 0.9 N by changing the aspect ratio from 0.25 to 1.00.

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A commercial AZ31 magnesium alloy sheet was tested under uniaxial tension, uniaxial compression and proportional biaxial tension. Bulge tests were also carried out to evaluate the plastic deformation behavior of the material over a larger plastic strain range than that obtained from biaxial tension experiments. The contours of plastic work and the directions of plastic strain rates were determined from experimental data and compared with those calculated using Cazacu 2004 yield criterion. It was found that Cazacu 2004 yield criterion can describe the asymmetry of the yield locus very well, while the measured plastic work contours other than those used as input parameters were in fair agreement with the calculated yield locus. The calculated directions of plastics train rates were found generally in good agreement with those measured except for stress ratios :σ _x σ _y =1:0 and 4:1.

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A method for analyzing the fringe pattern from a single image is proposed for interferometry and photoelasticity. The emerging light from a polariscope or an interferometer is analyzed using an optical setup of a polarimeter that is composed of two Savart plates, a half-wave plate, and an analyzer. Then, the distributions of the Stokes parameters are obtained. The phase distribution of the fringe pattern produced by the interferometer is then calculated from these Stokes parameters. Similarly, the phases of the isochromatics and the isoclinics in photoelasticity are obtained by analyzing the emerging light from the polariscope. The effectiveness of the proposed method is validated by simple experiments of interferometry and photoelasticity. Results show that the fringe pattern analysis from a single image is possible by the proposed method.

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The effects of projectile material properties on crater shape and ejecta in thick aluminum alloy 6061-T6 targets were investigated at velocities ranging from approximately 0.5 to 6 km/s. The projectile density affected the crater depth, but the projectiles hardness did not affect it. At the impact velocity of 6 km/s, the density of projectiles clearly affected the mass and size of ejecta fragments. The impact velocity clearly affected the diameter of ejecta rings. The ejecta ring diameter of metal projectiles was almost the same.

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In order to robotize construction machinery like a bulldozer, it is significant to investigate the relationship between the resistive forces acting on an excavating blade and the soil strength parameters, i.e., the cohesion and the angle of internal friction. In this paper, a method to estimate the soil strength parameters from the resistive forces acting on an excavating blade was examined from the results of two experiments, that is, direct shear test and soil-excavation test using a flat blade that resemble bulldozer parts. It was confirmed that each soil had their unique relationship between the soil strength parameters and the resistive forces acting on the excavating blade.

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Compressive properties of expanded polymer rib structures for automotive use have been experimentally investigated to clarify the effects of rib shape and deformation rate on compressive deformation behavior. I n typical expanded polymer rib structures, rib buckling occurs during the early stages of the deformation process. In this study, it is shown that this phenomenon is strongly affected by rib shape. Furthermore, the effect of deformation rate on the compressive properties of expanded polymer rib structures is shown to be small.

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A polarization sensor (POL-sensor) is a biomimetic sensor that uses the polarized light in the sky to determine the direction of the solar meridian. The ommatidium of an insect's compound eye uses paired channels to enhance the sensitivity to polarized light. Existing POL-sensors have a crossed-analyzer composed of paired phototransistors to mimic this characteristic. However, the large number of phototransistors used in these units makes them too heavy for use on small robots. We have made a POL-sensor without a crossed-analyzer. Our POL-sensor has half the number of phototransistors compared with a sensor using a crossed-analyzer, which makes our sensor much lighter. We have demonstrated redundant control of a small, wheeled robot using our POL-sensor together with a magnetic sensor.

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As for the structures built at rapid economic growth, obsolescence is progressing, and the accidents by damage are occurring frequently. As a cause for collapse of a structure, the load stressmore than assumption is considered. The aim of this study is to apply a grazing SH-wave acoustoelastic method to the stress measurement in actual angle steel used in power transmission steel towers. A new-type grazing SH-wave sensor was developed in order to measure the wave velocity of angle steel in a high accuracy. The search of optimal measurement area in stress evaluation and the grinding method for making a smooth measuring plane were also discussed. As a result, stress measurement for the angle steel was enabled, because the part which the influence of the bending is little was able to be found out.

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3-D shape measurement systems by contactless method are required in the quality inspections of metal molds and electronic parts in industrial fields. A grating projection method with phase analysis has advantages of high precision and high speed. Halation often occurs on a part of a metallic object. When the direction of the camera or the direction of the projector is changed, the halation area is changed. The results obtained by the several cameras are the same coordination system because the same reference planes are used for the calibration in a whole-space tabulation method (WSTM). Therefore, it is easily to merge the results obtained by the several cameras. In this paper, we develop a shape measurement system with several cameras. To reduce the number of the camera, two mirrors are used. The developed system and the experimental results to measure a metallic object are shown.

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The compressive and tensile properties of PLLA/PBSL polymer blends (90/10, 80/20, 70/30) were measured using a universal testing machine and split Hopkinson bar methods. The yield stress of static and dynamic compressive tests for the polymer blends decreased gradually with increasing PBSL. When PLLA/PBSL=100/0, 90/10 and 80/20, a wave-like shape such as Mackerel pattern were observed on the fracture surfaces of specimens after the static tensile tests. The fracture surfaces after the dynamic tensile tests were flat.

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The use of mechanoluminescent (ML) sensor in form of SrAl₂O₄:Eu (SAOE) film-coating to predict fracture in reinforced concrete structures is described. Four-point bending tests were performed, and strong and localized ML before cracking was found from the ML images of the SAOE film coated on the concrete surface. The location of the strong ML was in agreement with the location of the cracks caused by the increasing load. This indicates that crack formation can be predicted by using ML sensor. Along with loading, the real-time ML images also clearly showed crack growing on the concrete surface. The results show that the formation position, the propagation direction and the propagating process can be measured from the ML images directly and which crack is in developing can be judged by dynamic ML images. ML film sensor is available to predict fracture in reinforced concrete structures.

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The reduction rate of P₂O₅ in a 50mass%CaO-50mass%Al₂O₃ melt and a dephosphorization slag by carbon was investigated. The apparent rate constant of the reduction reaction of P₂O₅ in the 50mass%CaO-50mass%Al₂O₃ melt by carbon is determined. The activation energy for the reduction reaction of phosphorus in dephosphorization slag is calculated to be E=473 kJ/mol, and the chemical reaction is considered to be the rate-limiting step. Because the FeO content of the dephosphorization slag is much lower than that of the converter slag, the phosphorus is removed by the gasification, and it is expected that the separation and recovery of the phosphorus is possible.

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The effect of potentiostatic dissolution on the structure of a Cu-Zn alloy microchannel lining layer was investigated. The microchannel lining layer was fabricated by a powder-metallurgical process using copper powder and zinc wire. The lining layer became more porous after potentiostatic dissolution at a constant potential of −0.5 V vs. Ag/AgCl. The lining layer was remarkably dezinced and it contained many open pores under the dissolution condition at +0.5 V. These results indicate the possibility of precise structure control of the microchannel lining layer.

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The equilibration experiments of the Fe-Ag-Cu-B system were performed at 1873 K and 1523 K, and the distribution ratio of Cu between Fe-B and Ag phases was measured. As the B content of the Fe-B phase increases, the distribution ratio of Cu, L_Cu, increases. L_Cu becomes constant in the region of [mass%B](_{in Fe})>3.96 at 1873 K. The value of LCu is determined to be approximately 6 at [mass%B](_{in Fe})=3 in the region of [mass%Cu](_{in Fe})<0.73 at 1523 K. The first order interaction parameter of Cu and B in the Fe phase at 1523 K,ε ^B_Cu , is determined to be 4.6 (±0.7). The second order interaction parameter of Cu and B in the Fe phase at 1873 K,ρ^B_Cu , is derived to be −33.3 (±3.1).

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We investigated the influence of Zn on anodic oxidation of planner Al-Zn lining layers produced by a sacrificial-core method. The Al-Zn lining layer was produced from aluminum powder and zinc plate. By comparison with experiments using sintered aluminum powder compacts, it was found that zinc hindered the formation of nanoporous alumina film. The nanoporous structure can be formed on the surface of the Al-Zn alloy lining layer by long time anodic oxidation of 7.2 ks.

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A novel process has been examined to produce a free-form metal pipe containing thin channels. This process combined a sacrificial-core method and Metal Injection Molding (MIM). MIM compound containing SUS304 stainless steel powder was used as a body compound, and a compound with Cu powder was used as a sacrificial-core compound. These compounds were assembled and injection-molded, and then thermally treated for dewaxing and sintering. With an adequate heating treatment, the sacrificial-core metal migrated to the body-metal region, and thus a channel was successfully produced.

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The centrifugal combustion synthesis (CCS) process with a thermite-type combustion synthesis reaction can produce a joint of a cast Ni₃Al member and a dissimilar material. We verify effectiveness of filtration of the combustion-synthesized Ni-Al alloy on the distribution of by-product alumina inclusions in the cast member. In the specimen produced without filtration, coarse alumina inclusions were distributed. In contrast, no such a fatal defect was observed in the filtrated specimen.

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Effects of alkali leaching time on the composition and structure changes in the Al₃Ni₂ microchannel lining layer produced by a sacrificial-core method have been investigated. The composition was measured both on the specimen surface directly exposed to the leachant and on the new surface cut after alkali leaching. In each surface, the decrease in Al concentration became sluggish after formation of Ni₃Al. On the other hand, nano structure consisted of almost pure Ni was detected on the inner wall of the microchannel leached for 864 ks.

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A new process is proposed for the separation and recovery of rare-earth metals from magnet scraps. In order to investigate the electrolysis potential for the separation of Dy and Nd, cyclic voltammetry was conducted using a Ni electrode in a molten LiCl-KCl-DyCl₃ or LiCl-KCl-NdCl₃ system at 723 K. In cathodic scanning with the Ni electrode, a cathodic current was observed from 1.00 V (vs. Li⁺ / Li) as a result of the formation of Dy-Ni alloys in the molten LiCl-KCl-DyCl₃ system. In contrast, a cathodic current as a result of the formation of Nd-Ni alloys was observed from 0.60 V in the molten LiCl-KCl-NdCl₃ system. These results suggested that the separation of Dy and Nd could be achieved in the potential region 0.60-1.0 V. On the basis of the cyclic voltammetry results, an alloy sample was prepared by potentiostatic electrolysis at 0.65 V for 1 h using a Ni plate cathode in a molten LiCl-KCl-DyCl₃-NdCl₃ system. ICP-AES showed that the mass ratio of Dy/Nd in the alloy sample was 72. This result indicated the possibility of selective separation of Dy and Nd in a molten LiCl-KCl-DyCl₃-NdCl₃ system. Another investigation was performed in a molten LiCl-KCl-DyCl₃-LaCl₃ system, with and without FeCl₂, in order to confirm the selectivity. Regardless of the presence of FeCl₂, DyNi₂ was selectively formed on a Ni plate cathode by potentiostatic electrolysis at 0.55 V, which indicates a high possibility of separating Dy and La (Fe).

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Tooth displacement due to a bite force was measured using X-ray computed tomography (CT) images and coordinate transformation. Two CT images of the mandibular dentition of an adult male were recorded with and without a bite force. Tooth displacement was evaluated from the two images by matching them at the mandibular bone region using coordinate transformation. The following results were determined under a bite force of approximately 100 N at the first premolar: (i) displacement measurements of a tooth are possible using the present method, (ii) displacement was also observed at teeth without the bite force, (iii) displacement tended to be small in the direction of the tooth axis, but relatively large on the occlusal surface, and (iv) the absolute values of the maximum displacements were less than several hundred micrometers in the direction of the tooth axis and were nearly 1 mm on the occlusal surface.

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We have mainly focused on the elucidation of the physical skills of sports players. We have especially evaluated these skills from the biomechanical data obtained from sports. In this study, we analyzed the swing motions of skilled and unskilled baseball players by using two tri-axial acceleration sensors and two high-speed cameras. We showed some results of the skill rules of the swing motions by the skilled and unskilled players. It was also indicated that acceleration sensors are more convenient than the motion capture system for extracting skills from some data.

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We performed a three-point bending test and a torsional test using chicken bones to determine which type of testing is best suited to the evaluation of bone strength after medical treatment. Although the torsional test simulates the real bone fracture well, the coefficient of variation was larger than bending test and breaking location was not the same part to many bones. We then used the three-point bending test to investigate bone strength after a medical treatment and clarified that the bone strength has a high probability of decreasing.

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The movement of the molars of a lower jaw subjected to distal loads from an implant anchor, a correcting wire and brackets was investigated using a three-dimensional finite element method. The finite element model consists of the lower jaw, teeth, periodontal membranes, the correcting wire and brackets. The lower jaw and teeth were constructed on the basis of computed tomography (CT) images of a dried human skull. The Young's modulus of the lower jaw was obtained from the gray value data of the CT images. The implant anchor was not considered in the model. However, the position of the anchor was used to determine the direction of the force acting on the wire. The movement of the molars was compared with that of a lower jaw model obtained experimentally using a three-dimensional digital image correlation technique. Result sindicated that the movement of the molars depended on the position and direction of the load.

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A series of impingement wear tests on the three kinds of ultra-high molecular weight polyethylene (UHMWPE), namely conventional, cross-linked and vitamin E-doped UHMWPE has been performed. Water uptake of UHMWPE was measured first, and then the impingement wear tests were performed. An amount of wear in terms of weight change of UHMWPE with the cyclic impingement was not able to be determined, so the volume change in the wear section was alternatively measured. As a result, the vitamin E-doped UHMWPE clearly showed the smallest wear volume among these three UHMWPEs.

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