The use of 3D printing to manufacture trial models of a blood pump is expected to reduce the cost of development. In this study, an impeller whose geometry coincided with that of a commercialized monopivot centrifugal blood pump was made by 3D printing, and hydrodynamic performance, impeller rotating position, and hemolytic property of the assembled pump were compared with those of the production. As a result, almost the same pump hydrodynamic performance was obtained, but larger impeller dropping occurred in the 3D printing model than the production. This dropping increased the hemolysis level of the 3D printing model at high pressure condition. These results indicated that the trial model made by 3D printing could reproduce the hydrodynamic performance of a production but that we must pay attention to the deformation of the trial models to evaluate the hemolytic property.

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Mechanical circulatory support using a ventricular assist device (VAD) has been an essential therapeutic tool for patients with severe heart failure waiting for a heart transplant. To the enhancement of the therapeutic efficacy or safety and prevention of complications, advanced software functionality such as VAD drive control may be equally important as hardware improvements. However, controlling VADs in the realistic situation would be difficult because it is necessary to model the whole including the VAD and the cardiovascular dynamics. To solve this problem, we have proposed an autonomous VAD control method based on stochastic model. In this study, we sought to investigate whether a flow control application of our method can be used to adaptively control a continuous flow VAD. To evaluate behaviors based on the implemented algorithm, control testing on a mock circulation loop simulated a left heart bypass support and inflow sucking (unexpected event). These were compared with the linear flow rate control. As a result, the flow rate of the VAD reached a target value in both methods to changes of the circuit resistance. The behaviors to inflow sucking were found as follows: linear control failed by increasing rotational speed for the sucking. On the other hand, the proposed method reduced frequency of the sucking up to 12% by behaviors to searchingly decrease rotational speed.

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Extracorporeal circulation (ECC) is indispensable for cardiac surgery and cardiopulmonary support. Despite the fact that ECC is traumatic to blood components and non-physiologic, its influence has not been fully explored. However, difficulty in clinical research and animal experiments keeps the knowledge insufficient. Therefore, it is desirable to have a miniature ECC system for small animals, which enables repetitive experiments, to study the mechanism of pathophysiological changes during ECC. We establish a miniature ECC system and apply the system to the rat for investigating biochemical changes, and assess whether the rat ECC model is comparable to the human ECC. The ECC system consisted of a membranous oxygenator (polypropylene, 0.03 m^2), tubing line (polyvinyl chloride, φ2.0 mm) and roller pump. Priming volume of this system is only 8 ml. During CPB, the MAP and the Hb levels were maintained around 70 mmHg and 10 g/dl, respectively. Pump flow and blood gases were normally maintained in the both groups. On the other hand, TNF-α, IL-6 and IL-10 levels were significantly elevated in the ECC group, indicating some organ damages and systemic inflammatory responses during ECC. We successfully established the ECC for the rat. This miniature ECC model could be a very useful approach for studying the mechanism of pathophysiology during ECC and basic assessment of the ECC devices.

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This paper describes visualization of thrombus formation process on wall surface of the tube. The aim is to investigate the effects of shear stress or shear rate, especially constant shear rate using Couette flows, on the thrombus formation. In this investigation, by visualization of the thrombus formation in blood plasma flow, it was found that the flow rate and shear rate has large effects of the thrombus formation rate. The thrombus formation rate in the Couette flow was obtained by special double cylindrical test rig. It was found that higher shear rate makes large thrombus formation rate by comparing share rate 100rpm (164 [1/s]) and 300 rpm (492 [1/s]). It was also found that the profile change suddenly when the shear rate is high. In the presentation, the prediction method using CFD is also proposed.

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In this paper, we described a novel phantom experiment method with flexible stenosis tube, for use of circulatory simulation by fluid-structure coupled analysis. Recently, factional flow reserve (FFR) for evaluation approach of coronary stenosis has received a lot of attention. However previous technics is still difficult to measure the FFR values, because catheter surgery is required. To solve this problem, we have developed a novel approach based on four-dimensional computed tomography (4D-CT) image tracking and structural and fluid analysis named 4D-CT FFR, promising minimally invasive for patients. Here we demonstrated phantom experiment with flexible stenosis tube, and indicated relationship between deformations of the tube, pressure loss and flow rate, for validation of 4D-CT-FFR.

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The fluid-structure simulation of flexible stenosis tube is performed to develop non invasive fractional flow reserve derived from CT coronary angiography (CT-FFR). As a result, it turned out that; 1. The relationship between pressure loss and flow rate of the flexible stenosis tube has a hysteresis loop. 2. The relation of pressure loss, extension of the tube, and stiffness can be approximately expressed by modifying the dynamic expression of relations of the blood vessel proposed by Olfusen et. al.. 3. When a flexible tube contracts from near the maximum flow rate, the extension state and flow dynamics in each time change statically, and consistent with an experimental result even if the analysis substitutes the steady one in a pipe extension state of each time. 4. When the tube contracts from near the maximum flow rate, one-dimensional fluid analysis is also adjusted with an experimental result about a stenosis index.

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As evaluation of hemodynamics in an aneurysm, a lot of parameters have been introduced. However, the relationship between stent geometry and each hemodynamic parameter is not clear enough. We applied Self-organizing Maps (SOM) to search the detailed relationship between stent strut and hemodynamic parameters. Two thousands of stent design candidates evaluated with five hemodynamic parameters and 25 stent geometry parameters were stored during the optimization process. By using SOM software, 2,000 design candidates were visualized into 30 2D-maps while preserving their own features in the original 30-dimensional design space. Each map was divided into 20 clusters to characterize stent design and flow reduction. By comparing each cluster, critical design for reduction effect of each hemodynamic parameter is suggested. Strut placement on the inflow area is important to reduce maximum shear rate. In addition to the inflow area, strut on the outflow area is required to reduce velocity, vorticity, and average shear rate.

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A coronary stent is a tube-shaped device, which needs a vascular wall crimp power and bending stiffness reduction, so that a stent matches the blood vessel without any damage. But, in a stent end, its radius increases locally (Dog-Boning), which has an effect to fix a stent to the vascular wall, but an uniform crimp pressure distribution is more desirable. With this background, the balloon for stent expansion is modeled by SHELL elements with contact detection, and after the nonlinear FEM analysis, the Dog-Boning behavior is replicated. The results of analysis is described here in after.

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We have been developing microporous covered stents for a treatment of intracranial aneurysm (IA). This device promotes flow reduction and induces progressive thrombosis in IA. In this study, we investigated intra-aneurysmal flow with various curvature ratios of parent vessel by using in vitro flow simulator. Two-dimensional sidewall IA models were fabricated from acrylic plastic. Parent vessels shape were designed on a straight and U-bend shape (curvature ratio: 0, 0.125, 0.250, 0.500, 0.667) models. Reynolds number in the parent vessel flow was set between 160 and 980 in steady flow. Microporous stainless-steel sheet (pore diameter: 100 μm, porosity: 30 %) was prepared as a stent model. Distributions of velocity and shear rate of intra-aneurysmal flow were measured by particle image velocimetry. As the result, faster intra-aneurysmal flow was observed in the case of sharper bended vessel model. Area mean shear rates in the case of the U-bend vessel model (curvature ratio: 0.500) was about 5 times higher than the case of straight vessel model. After stenting, the area mean shear rates at the all IA models were decreased to about 12 % of before stenting. It is suggested that our developing microporous covered stent has a good embolization performance, if the aneurysm is created at such curved vessel.

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Stenting is a common treatment of stenosis. One of problems of stent treatment is restenosis. Local hemodynamic factor such as low wall shear stress (WSS) is one of the reasons for restenosis. Therefore, blood flow analyses have been performed to clarify the restenosis mechanism. Fluid-Structure Interaction (FSI) is used for blood flow analysis to consider the interaction between fluid pressure and structure deformation. In this research, the effects of the deformed vessel by stenting and pulsating flow are analyzed using FSI. The stent expansion analysis was performed to obtain the deformed shape using FEM analysis software ANSYS Mechanical APDL. FSI analysis was performed to examine the effect of a pulsating vessel using ANSYS Workbench. An initial stent model was made based on the shape of before the expansion. The expanded stent model was also made based on the shape of the expanded stent. To reveal the effect of pulsatile on the blood flow after the stenosis, two boundary conditions were employed; rigid wall and FSI. Inlet flow rate was assumed to be expressed by a periodic function to reproduce the pulsating flow in the carotid artery. The results of velocity, pressure difference and WSS are shown for each model and condition. In the case of rigid wall, WSS at the stenting site is reduced by the expansion of the vessel.

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This paper describes an effect of using new ferrous polycrystalline shape-memory alloy showing huge superelasticity and higher stiffness as a self-expanding stent material. In this research, stent deployment analysis was conducted by using finite element analysis (FEM) software ANSYS 15.0. Nitinol self-expanding stents are widely used for artery stenosis treatments due to their high flexibility. However, the radial stiffness of self-expanding stents is low compared to balloon-expanding stents. Stent, artery, plaque, and sheath models were made for FEM analyses and the analytical results after deployment of nitinol and ferrous alloy stents were compared. In addition, two methods of the unsheathing were studied: (1) the conventional method where a stent comes out from one end of the sheath and (2) a new method in which stent comes out from the center of the sheath. FEM results showed that the radial force of the stent made of the new ferrous alloy was higher than those of nitinol. Meaning that the ferrous alloy stent displaces the plaque more than the nitinol stent. Furthermore, the plaque was displaced more using the new method of unsheathing, and the ends of the artery without the plaque showed smaller displacement. These results suggest the effectiveness of using the ferrous alloy for self-expanding stent.

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Accidents of head injury have been increasing since judo became a required class in junior high school at April 2012 in Japan. Although typical injury in judo is concussion and acute subdural hematoma by head collision to the judo tatami, effective guideline for prevention based on biomechanical point of view has not been proposed. In this study some Waza to cause a risk to hit a head on a tatami were performed by judo players and recorded by VICON system. These motions were reconstructed by MADYMO by using VICON data and kinetic data and hit part of a head on the tatami, which were used as input data for a FE human head model, were obtained. The strain and stress of the brain tissue were calculated in detail by the FE human head model and injury risk was predicted.

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DAI (Diffuse Axonal Injury) is known for severe brain injury and having high occurrence rate in traffic accidents. DAI caused by deep brain distortion arisen from head rotational motion, however the detail mechanism is not clear. Therefore sufficient safety measure for DAI is not taken even now. In previous studies, consider DAI occurrence mechanism by using physical model or simulation model. However, these studies were confined to consider injury mechanism under limited external force condition. Therefore consideration to injury mechanism under external force condition assumed traffic accidents is necessary for more elucidation of injury mechanism. Then, this study analyzed head motion and deep brain distortion of occupant in traffic accident by simulation using human and vehicle finite element model and disccuss DAI occurrence mechanism. Simulation on five kinds of collision forms carried out, whose forms are FRB (Full-lap Rigid Barrier) frontal collision, ODB (Offset Deformable Barrier) frontal collision, SORB (Small Overlap) frontal collision, MDB (Moving Deformable Barrier) side collision and POLE side collision. Also the head of human finite model was improved to occur a relative motion between brain and skull. As a result, high strain at corpus callosum and brainstem which is focus of DAI, were due to head convolution and lateroflexion respectively. Then, results of this study showed that SORB frontal collision, MDB side collision and POLE side collision cause such head motion.

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Intracranial pressure changes during head impact cause brain injuries such as vasogenic edema and cerebral contusion. The purpose of this research is better understanding of the effect of impulsive pressure during head impact on the disruption of blood-brain barrier (BBB) that forms a physical barrier to filter blood-borne substances between the blood and the brain parenchyma. Firstly, changes in the capillary-like network formed by endothelial cells were observed using an inverted microscope. The capillary-like structure was broken down after 1 h following impulsive pressure, and the capillary network gradually disappeared until 24 h after loading. Then, following impulsive pressure loading, transendothelial electrical resistance (TEER) was measured using the in vitro BBB models consisting of cultured endothelial cells, pericytes and astrocytes from rat brain capillaries. Lower TEER indicates the disruption of endothelial integrity and the formation of intercellular gap. In the result, TEER decreased immediately after loading and the decrease in TEER was larger in the co-culture model with endothelial cells and astrocytes than in the endothelial monolayer model or the co-culture model with endothelial cells and pericytes. These results suggest that the impulsive pressure during head impact impair endothelial barrier function by the disruption of the integrity of endothelial cell-cell junctions, and the degree of increase in endothelial permeability depends on injured cells that compose BBB.

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For estimation of brain injuries in collisions, a brain finite element (FE) model has been developed in this study. Currently some researchers in all over the world have developed their original brain FE models. However, the element size and the material properties of brain matter are different between their brain FE models. Accurate prediction of brain matter strains is critical because brain injuries may be estimated by Cumulative Strain Damage Measure (CSDM), which is defined as the percent volume of the brain that exceeds the specified first principal strain, calculated by using a brain FE model. However, it is not clear how the differences in the brain FE models affect the brain matter strains. In this study, parametric study was performed to investigate factors that affect brain matter displacements during head rotational impact using a brain FE model. The parametric study demonstrated that brain FE models with smaller element size, smaller short-term shear modulus, and smaller decay constant could increase the maximum displacements of brain tissue and the CSDM.

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Diffuse axonal injury (DAI) is caused by sudden inertial loading to the head associated with rapid deformation of brain tissue, resulting in the stretching of neural axons. Periodic swellings along axons and axonal bulbs at disconnected terminal ends of axons that are the morphological hallmarks of DAI pathology lead to the disconnection of neurons from tissues, resulting in cell death. The β-amyloid precursor protein (β-APP) that is conveyed by axonal transport and Tau protein that is associated with axonal microtubules accumulate where axonal transport is disrupted. In this study, the cultured rat brain neuronal cells were stretched to strains of 0.10-0.30 at strain rates of 4-50 s^<-1>. The sham control is put in the stretching device without mechanical loading and then is incubated under conditions of 5% CO^2 and 100% humidity at 37℃. β-APP and Tau protein were stained at 3 h post-loading and observed using fluorescence microscopy. As a result, β-APP and Tau protein accumulated in swellings and bulbs following stretching and accumulated axons significantly increased following strains of more than 0.22 in a strain-dependent manner compared to sham control. However, there were slight changes with regards to the dependence of strain rates. These results suggest that the threshold of interruption of axonal transport is 0.22 strain.

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In this research, the fabrication conditions of Ti-29Nb-13Ta-4.6Zr(TNTZ) alloy by pulse-current sintering and the properties of the alloy were investigated experimentally. The sintering was performed at various temperatures in a vacuum, and then the solution treatment was carried out in Ar gas atmosphere. As a result, the alloy sintered at 1273 K was showed almost full density. The microstructure of the as-sintered alloy became β-phase by solution treatment. The tensile strength and elongation of the solution-treated alloy were 539 MPa and 12.3 %, respectively. The Young's modulus was around 60 GPa and was similar to that of the wrought alloy.

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Powder rolling is a possible way to produce grain-orientated ceramic materials with using plate-like powder particles. Orientation behavior of ceramic particles, plate-like alumina as a model material, during differential speed rolling was examined to seek the optimum condition of rolling. Powder particles were kneaded with an organic binder to plasticize, and slab specimens were formed in dies. The specimens, without any sheath, were rolled with changing the difference in rolling speeds of two roll. The average of the orientation angle and the standard deviation of the angle distribution obtained by image analysis for each plate-like particle were evacuated as the degree of orientation. The degree of orientation became higher as the ratio of roll speeds was increased.

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The composite journal bearings which have outer layer with high strength and inner layer with high wear resistance can be used as bearing materials in the industrial high-power machine. The complex layer bearing prepared by unification forming of two different mixed powders with Fe-Cu-C in outer layer and Fe-Cu-C-Ni-Cr in inner layer, and then it was sintered for 9.0ks at 1403K. The sliding property to hardening steel shaft of the complex layer bearing was invested by swing-type sliding machine. The wear properties in this bearing were examined and also estimated on the connection with the wear property of rotary shaft. Wear loss volume of complex-layer bearing is extremely lower than the single-layer bearing. However, There is a slightly difference the wear-loss volume of rotary shaft by the swing-type sliding for the complex-layer bearing and single-layer bearing.

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Ubiquitous light elements (ULEs) like oxygen (O) and nitrogen (N) are the promising additive elements to achieve the high specific strength and cost-effectiveness of powder metallurgy (PM) titanium (Ti) materials. The ULEs are employed as useful reinforcements instead of the conventional alloying elements of expensive rare earth metals like vanadium (V). In the present study, nitrogen atoms were directly induced into titanium powders via gas-solid reaction process. The treated powders were consolidated by spark plasma sintering (SPS), heat-treated under vacuum atmosphere and then hot-extruded. The homogenization heat treatment (HT) dramatically improved the homogeneity of nitrogen distribution in SPSed Ti-N materials. After HT and hot extrusion, the additive nitrogen atoms were uniformly dissolved into Ti matrix as solid solution reinforcement, which enhanced the mechanical responses of extruded Ti-N materials at ambient temperature. For example, extruded Ti-0.69mass%N material exhibited 1004 MPa YS, 1174 MPa UTS and 18.3% elongation in tension.

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In this study, based on the linear fracture mechanics, we proposed the Finite Element analysis method to consider with the dispersions of material parameter of ceramics due to sintering. Using proposed method, we can examine the fracture modes depending on the relative density, the initial defect (pore size), and the grain size. In addition, we can analyze the Weibull distribution within the framework of FEA.

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Tensile tests of the transparent conductive films used in DSC (Dye-sensitized solar cell), consisting of ITO (Indium tin oxide) coating and PEN (Polyethylene naphthalate) substrate, were carried out and the damage accumulation process was monitored using acoustic emission technique. Damage initiation in ITO layer was detected earlier by AE technique than the electric resistance measurement during tensile tests. AE generation behavior was consistent with the result of in-situ observation of cracking behavior; initiation and saturation of transverse (perpendicular to tensile direction) cracking followed by the longitudinal (parallel to tensile direction) cracking due to buckling. Utilizing the principle of "fragmentation tests" for composite materials, interfacial shear strength for ITO/PEN interface was evaluated from experimental results for the critical strain at crack saturation and the spacing of saturated cracks. Finally, it was found that the shear strength was degraded by GBL (γ-Butyrolactone) used as electrolyte in DSC.

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The effects of mechanical loading conditions on power generation property of PZT piezoelectric ceramic were investigated. In this approach, several PZT ceramic plates were combined together in the longitudinal direction. The electric voltage increases with the highest electric voltage being obtained for four PZT ceramic plates; and the maximum electric voltage becomes almost constant even if number of PZT ceramic plates combined together increases more than four. This is attributed to the low strain level and the mixed strain (compressive and tensile strain). The effect of strain characteristic on the electric voltage value was analyzed numerically using our strain definition, and a clear correlation between the extent of compressive strain and generated electric voltage is clarified.

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This paper describes evaluation method of fracture properties of fiber-reinforced self-healing ceramics. Fiber-reinforced self-healing ceramics (shFRC) are considered to be one of the most attractive candidates for next generation structural materials using at high temperature, e.g. turbine blade of the jet engine, exhaust component of car engine etc. The shFRC consist of three components, which are oxide fiber bundle, oxide matrix and self-healing agent interlayer. As the self-healing reaction occurs at only the interlayer, it is necessary that crack propagation should be led into the interlayer. As a result, shFRC exhibit quite complex fracture behavior. In order to assess the structural integrity of shFRC accurately, the correct fracture toughness including the complex fracture manner is extremely needed. In the present study, the fracture toughness and the fracture behavior of shFRC were investigated by using the beam with chevron notch. In addition, the self-healing effect on the fracture toughness was discussed.

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This paper describes that strengthening of fiber-reinforced self-healing ceramics (shFRC) is achieved by decreasing the defect size in fiber bundle and employing high strength interlayer. The shFRC was proposed as one of the candidate materials for turbine blade and consists of three components, which are oxide fiber bundle, oxide matrix and self-healing agent interlayer. When crack is initiated in shFRC, the crack can be branched along interlayer designed as weakest region. The crack propagation is arrested due to friction of interface. The crack is filled up and bonded by oxide of self-healing agent and the strength of the shFRC recovers. Due to large defect size in fiber bundle, however, the strength of the shFRC is too low to apply turbine blades. To enhance mechanical strength of shFRC for actual applications, the present study aims to develop the advanced shFRC with small defect fiber bundles. To decrease the defect size in fiber bundle, the used fiber bundles was applied under tensile stress before the interlayer coating. As a result, the diameter of fiber bundles were shrunk to 2 thirds of the original diameter. Using the small defect fiber bundle allows to employ the high strength interlayer. Thus, 50 wt% TiSi_2/ SiC interlayer was used in the advanced shFRC. As a result of three point bending test, the advanced shFRC had 386 MPa strength. Since the materials for turbine blade are required to have more than 137 MPa, the advanced shFRC has enough high strength to apply for turbine blade.

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This paper describes development of a smart breakwater or river bank using honeycomb-like structure to be adaptive to change of water level. A designed cell is deformed using a tensile test machine, and the results show that the honeycomb cell can deploy up to double of is original height without plastic deformation and the deformation is reproducible. It is stacked up to twelve layers and similar performance can be found. In addition, a six-layer deployable model is prepared and it became clear that the model can change its height in proportion to the water height in the experimental range and successfully block the water.

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After the Great East Japan Earthquake and Tsunami, seaside cities have prepared evacuation plans, hazard maps, evacuation buildings and so on. These preparations will prevent damages. Prevention, however, does not realize expected effects, because they suppose non-handicapped people. It is difficult to have disaster dills including handicapped people for estimating time required for evacuation. Thus, a simulation for mass evacuation including handicapped people is important. This paper shows results of an experiment supposing evacuation from tsunami to refine the simulation of mass evacuation.

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This paper describes energy decrease of water current by flowing into the multiseriate cylinder type wave mitigation structure. This structure is based on tsunami mitigation coastal forest effective to reduce tsunami disaster. However, natural forests have many problems such as low fraction of trees, low visibility of ocean waves, low strength, long time to grow, and so on. In order to cope with these problems, a multiseriate cylinder type wave mitigation structure has been proposed, which are intended to have better capability of high wave or tsunami mitigation than actual ones by optimizing various parameters such as configuration, density and material. In this study, the effect of type of material, that is, stainless steel (SUS304), aluminum alloy (A2017-T4) and polyacetal polymeric (POM) were compared as a function of number of rows. Furthermore, structural vibrations were measured by using acceleration sensors. According to the results, reduction rate of the flow velocity increases with increasing number of rows for both materials, and that of cylinders having lower Young's modulus is generally higher than that of cylinders having higher Young's modulus. This tendency is considered to be caused due to easiness of vibration.

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To measure the deformation of the structural material, Irradiated grid or grating fabrication method has been developed. Using a laser projector, squire grid or parallel grating was irradiated to the specimen which has luminous paint on the surface. After ten minutes irradiation, a grid or grating can be observed of bright and dark parts. Bright parts were irradiated by laser beam and can be observed in 1 minute. 3-point bending test was performed after ten minutes irradiation of laser, and grid could be observed during 3-point bending test.

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Japan has the special feature that there are a lot of natural disasters compared with other country. The volcanic explosion at Mt. Fuji has been paid attention recently. If aerosol-like volcanic ash is inhaled from the air intake in those land-based gas turbines, all generators would be stopped and then a blackout would be occurred in the whole Kanto area. In this study, deposition behavior of volcanic ash under a high-temperature gas flow was examined. In order to achieve this purpose, the volcanic ash deposit simulator, which can simulate a combustion flow, was developed. Subsequently, the volcanic ash deposition test was conducted, and a high-temperature exposure test was also performed for the ash-deposited sample.

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Mechanical coating technique (MCT) as a novel film formation process has been proposed and developed based on mechanical frictional wear and impacts among Al_2O_3 balls, columns, disks used as the substrates, and metal powder particles used as the coating metal in the bowl of planetary ball mill or pot mill. Metal films of Ti, Cu, Ni, Fe and Zn on alumina balls were prepared by MCT. Further, 2-stap MCT was developed based on MCT concept for preparing TiO_2/Ti composite films on alumina balls. The investigations for the formation process of the metal films and the applications of MCT are also promoted. Also, Al_2O_3 balls, ZrO_2 balls and steel balls have been used the substrates in MCT. In this work, stainless steel balls were used as the substrates for Ti films in MCT. The formation process of the Ti films was investigated and discussed. The formation process of Ti films on stainless steel balls is similar to that using Al_2O_3 balls or steel balls as the substrates, including the nucleation by adhesion, the formation and coalescence of discrete islands, formation and thickening of continuous coatings, exfoliation of continuous coatings.

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Additive manufacturing technologies, such as powder bed fusion, are promising technologies that could significantly reduce the length of time between initial concept and finished part. These provide designers to create complex and innovative products. Still, process induced imperfections, i.e. residual stresses upon processing and surface roughness, need to be considered for future application. In this paper, Inconel718 was fabricated by selective laser melting (SLM) using Yb fiber laser in argon gas from fine pre-alloyed powder. The powder was observed by X-ray diffraction and only matrix γ phase was detected. In the as-built specimen, high density cell structure and Nb-rich precipitates were observed. Tensile specimens were cut parallel (0° specimen) and perpendicular (90° specimen) to the laser beam direction. As-built, STA (Solution heat Treated and Aged) and DA (Direct Aged) tensile specimens were prepared. HIP (Hot Isostatic Pressing) process was also applied. At a room temperature, strengths and ductility were higher than conventional material and obvious anisotropy was not observed between 0° and 90° specimens. However, a ductility of STA 90° specimen was much lower than that of STA 0° specimen at 650℃. After HIP process, this anisotropy was found to be decreased. Microstructures were observed by SEM, EBSD and TEM. Long and thin columnar and mixed-size grains were observed in as-built specimens built up parallel and perpendicular to beam direction, respectively. Through HIP process, the long and thin structures were changed to coarse and equiaxial grains.

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Electrical conductivity and temperature characteristic of resistance of Cu micropatterns which were fabricated by femtosecond laser induced thermal reduction of CuO nanoparticles (NPs) was investigated. The Cu micropatterns were obtained by femtosecond laser irradiation of CuO NPs film which included CuO NPs, ethylene glycol as a reduction agent and polyvinylpyrrolidone. Composition ratio of Cu and Cu_2O of the micropatterns was evaluated by comparison of Cu/CuO and Cu_2O/CuO principal peak intensity ratios of X-ray diffraction spectra. When the scanning speed was 500 μm/s and pulse energy was 1.2 nJ, the most Cu-rich micropatterns were achieved. Besides, the temperature dependence of the resistance of Cu- and Cu_2O-rich micropatterns were evaluated. The resistance of the Cu- and Cu_2O-rich micropatterns were respectively increased and decreased with the increase of the temperature. The temperature coefficients of resistance of Cu- and Cu_2O-rich micropatterns were approximately 1.0×10^<-3>/℃ and -1.5×10^<-2>/℃, respectively. These results suggest that Cu- and Cu_2O-rich micropatterns have semiconductor and metal temperature characteristics of the resistance. This higher sensitivity of Cu_2O-rich micropatterns can be applied for micro-temperature sensors effectively.

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We proposed fabrication process of nickel (Ni) microstructures using femtosecond laser reduction of NiO nanoparticles (NPs), and evaluated patterning properties of the Ni microstructures. In this process, NiO NP solution was prepared by mixing NiO NPs, ethylene glycol as a reducing agent, and polyvinylpyrrolidone. Then, NiO NP solution film, which was obtained by spin-coating of the NiO NP solution, was irradiated by femtosecond laser pulses in the air. As a result, NiO NPs were reduced to form Ni microstructures using thermal reaction induced by the laser irradiation. When the pulse energy was as low as 0.24 nJ, the line width was constant to be approximately 10-15 μm without depending on the laser scanning speed. This small and constant line pattern is advantageous for high resolution patterning. Crystal structure of the micropatterns was evaluated using XRD (X-ray diffraction). Maximal ratio of the XRD peak intensity of Ni to NiO was obtained under the condition that scanning speed was 1200 μm/s at pulse energy of 0.24 nJ. Using this laser irradiation condition, Ni microgear was formed. The thickness of Ni microgear was approximate 10 μm as almost equal to the NiO NP film by Field Emission Scanning Electron microscope observation. The Ni microgear enabled to be controlled by external magnetic field.

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Additive manufacturing may be a novel method for fabricating porous materials. These materials can achieve effective performance because of their internal geometries. Metal-additive manufacturing is expected to utilize thermal conduction materials and devices. We have developed a porous metal with effective isotropic thermal conductivity by using metal-selective laser melting additive manufacturing. The internal pore-structure was designed by topology optimization, which is the most effective structural optimization technique to maximize effective thermal conductivity. The designed structure was converted to a three-dimensional STL model, which is a native digital format of additive manufacturing, and assembled as a test piece. Effective thermal conductivity was measured by a steady-state method in which the effective thermal conductivity was calculated from a one-dimensional temperature gradient and the heat flux of the test pieces.

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Powder bed fusion type Additive manufacturing is a new production method for metallic parts that are in possible to product by conventional process. However the process parameters are not clear. In this paper, we consider the heat conduction on laser melting by using simple experiments. We have done one layer process with/without products under testing layer. The PBF method is a typical layer by layer process, usually the constructing point is made on the bottom structure. The thermal conductivity of bulked structure and powder is not same, the powder is lower. The results shows bottom structure affect to decrease the melting depth. The bottom structure decrease the melting efficiency from 0.2 to less than 0.1. Therefore, we must consider the heat conduction of the bulk material fabricated before under the powder layer.

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In 3D printing methods such as FDM, the direction of printing dominates the appearance and the nature of the printed objects. However, the direction cannot be specified in conventional 3D-printing methods. In this presentation, methods for designing and printing direction-specified 3D objects and the advantages of these methods are described.

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3D printing systems deposits melt or soften materials in a layer state on solid parts. Layered structures are much interfaces formed in the whole products, and extreme low strength interfaces are fabricated at the same time. It is necessary to optimize a printing direction according to the load that determines the strength and durability of the product as one of manufacturing process. Our study investigated an optimal molding direction procedure with respect to mechanical properties. Tensile and three points bending tests were done for standard plate type specimen made of polymer (ABS-like, Stratasys Co., Ltd) using Ink-Jet-Type 3D printer (Connex500). We made three types of specimens, which were varied in the printing direction, respectively. These experiments mean that the effect of directions of layers entering in the molds on important mechanical properties. Three type specimens for tensile direction were molded as follows: (S1) vertical molding with vertical layers to tensile direction, (S2) plane molding with vertical layers to tensile direction and, (S3) plane molding with printing layers parallel to tensile direction. Experimental results of tensile strength, Young's modulus and Elongation at break of each specimen showed remarkable differences. The detail results were as follows: tensile strength of (S1) 35 MPa, (S2) 39 MPa, (S3) 50 MPa, Young's modulus of (S1) 1.2 GPa, (S2) 1.4 GPa, (S3) 1.8 GPa and Elongation at break of (S1) 7 %, (S2) 43 %, (S3) 42 %. Bending test results showed the similar tendency of those of Young's modulus. These results became clear strongly significant specific anisotropy of mechanical properties related to printing directions. Therefore, establishment of DDM needs the logical molding process and construction of the database of mechanical properties of individual materials.

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In this study, cylindrical type 3D printer using fused deposition modeling method is proposed. This proposed devise is particularly suitable for modeling a cylindrical shaped object having overhanging parts as represented by Archimedes' screw. When a screw is molded with a standard 3D printer, it is necessary to support screw flights by molding support materials under those parts. However, molding of support materials interferes with the efficient modeling. In addition, the work of removing support material after molding is troublesome. The proposed devise allows the molding of a cylindrical object without support materials by adopting a cylindrical print bed. An extruder for melting and discharging a resin is placed just above the print bed and is moved in parallel to the rotation axis of the print bed. The print bed and the extruder are cooperatively moved according to a molding algorithm. In this paper, an overview of the prototype devise, molding algorithms and a result of preliminary test are reported.

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In this study, we propose and develop a versatile microstereolithography system using a low-cost diode laser. This system enables to generate pinpoint photopolymerization at a focused spot inside a liquid photopolymer like two-photon microfabrication using a femtosecond pulsed laser. In addition, it also takes advantage of multiscale fabrication based on single photon process. We constructed a microstereolithography system using a 405 nm diode laser and galvano-scanner set. Then, the resolution of this fabrication system was experimentally examined. By using this system, we successfully fabricated three-dimensional (3D) microstructures including movable microparts. Moreover, large scale fabrication of 2D alphabetical patterns was demonstrated.

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Softpastel, lightly pressed with body pigment, has various colors close to the color pigments. We built the hypothesis that a certain volume of body pigment provides delicate nuance of color, tone, and texture to soft pastels. We examined the effect brought by two types of body pigments regarding color and strength respectively. Experimental results supported our hypothesis. About color, we obtained lower numerical values of Value and Chroma when we used porcelain clay than calcium carbonate (CaCO3). In other words, calcium carbonate produces light and bright color, and porcelain clay produces tint or neutral color. Concerning hardness, applying porcelain clay, strength was further increased than CaCO3. Furthermore, we examined the relationship between the drawing medium (pastel) and the support medium (paper etc.). The result showed that the drawing medium strength decreases pigmenting with a weak pressure becomes capable. But easy pigmenting does not always mean generating rich and various color tones. Those facts suggested the possibility that optimum numeric value in medium strength would be find out, which enable us to perform broader expression.

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The hanging scroll is a traditional mounting format for paintings. The scroll must be hung straight when it is displayed, and rolled up smoothly when it is stored. For making this two function possible, the scroll mounter used traditional wash papers and a starch paste for lining. The paste is usually diluted with water for preventing that the paste becomes stiffen after dried, and it cannot have enough adhesive power by itself. And the mounter uses the special pounding brush for getting the strong adhesives. When the lining papers are applied onto the appropriate position, the surface of the lining papers is pounded. This pounding technique is required the matured experience and it is said that it takes such a long time to learn this traditional technique. If the pounding power is too strong, the lining paper, which is adhered, will get damage. On the other hand, the pounding power is too weak, the lining paper will not adhered properly. In this study, the load measurement of the pounding brush will be introduced with using the pressure measurement film. In addition, the comparison of the pounding technique between expert and non-expert is researched for understanding the appropriate traditional pounding procedure.

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We grasp the processes of an expert about the production of the handmade Japanese paper of Shuso in Ehime and the physical behavior in those processes. And, we find out the expert's skills that keeps the quality of the uniformity while long manufacturing time. We report the result of interlocking movement characteristics of the waist and neck in this study. The results of this reseach show that the neck movement of the expert has the fibers of Japanese paper tangle randomly. They also show that the expert modulates the quantity of the fibers by changing the height of the waist when he scoops up the fibers.

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There is a polishing process in the Maki-e decoration making process in the Urushi crafts technique. In the Maki-e decoration technique, metallic powders are sprinkled on the surface of Urushi painting. After that, the powders are coated by another Urushi. When the Urushi is hardened, the surface of Maki-e is polished by a charcoal. Because this process affects a finish of Urushi crafts work, this research aimed to clarify a use of craftspeople body in the polishing process. Muscle function was measured with an electromyogram (EMG) in an expert and a non-expert. As the results, expert stabilized his shoulder joint, elbow joint and hand joint, non-expert did not stabilize their joints. Therefore, the expert can polish the Maki-e surface clearly, but the non-expert cannot do the same.

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Rice cakes or "Mochi" is not only a traditional food of Japan, where rice is a diet staple and even mentioned in the ancient text of Kojiki. Mochi-pounding has always been a big group event held at large family or community gatherings. And, Japanese sayings such as "Mukashi totta kinezuka" (A skill one learned in one's former days) and "Mochi wa mochiya" (Every man to his trade) indicate that mochi-pounding requires a certain amount of expertise or experience. Mochi-pounding is done in pairs -- one referred to as the "tsuki-te" to bring down the hammer, and another one referred to as "aino-te" to add water (so that the mochi doesn't stick to the sides of the mortar) and turn over the mochi as it gets pounded. In this study, we focused on the action of pounding on the mochi. We paired the same experienced aino-te with three inexperienced tsuki-te -- each of different age, nationality and strength, and conducted three-dimensional motion and visual analyses. As a result, we clarified the difference of movements between the expert and beginners and how making ochi efficiently.

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Greeting is the basis of Omotenashi, and one of the ways to greet is to bow. Bowing has different shades of meaning according to the country or region, but generally speaking it is the action of bending from the waist to greet someone, express thanks, or apologize. In this paper, we conducted an experiment on the difference in maneuver between an experienced and inexperienced person by recording their movements using a video camera and measuring the positions and timing of the bowing motion. The bow of the experienced person had a stable angle, with the shoulder angle (θ1) being around 180 degrees all three times, in other words the head was straight. The angle of the waist (θ2) was at around 20 degrees all three times. For the Japanese inexperienced test subjects, they were made to do a bow that they thought were proper way three times, and θ1, θ2 were measured. As a result, type of movement could be divided into three types. When teaching the bow, considering of these types, it is possible to deepen the teaching method.

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"Kana-ami" is a kind of metal wire network in Japan, which was once prevailed many years ago in the old Japan and has been decreased in the development of social industrialization. In this research, the accurate "Kana-ami" structure was clarified by X-Ray. And the advantage of the expert's product was confirmed. The three-dimensional analysis method was applied to present the different actual structure. The three-dimensional result was analyzed by software. The tiny structural characteristics made by expert and non-expert were visualized and compared for each other.

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Metal heat treating is the fundamental technology to support most of the industrial field as automobile and aircraft. Since the quality of the heat treatment cannot be determined from the appearance, microscopic examination by means of the metallographic test specimen prepared from the products and components that require strength is performed. To acquire the real structure of the part, the cross section of the metallographic specimen shall be mirror surface finish without harmful scratches or edge rounding. These metallographic specimens are prepared by a few number of skillful inspector. Since the number of skillful inspector for grinding technique of metallographic sample is less, successor education is rely on not the systematic education but the on job training basis. The purpose of this study is to clarify the expert's characteristics of polishing process based on the eye movement analysis and ground surface finish. As a result, the expert made pressure adjustments and cleaning the rotating clothe surface and supplying alumina as needed while performing the grinding and polishing. The variation of the width for scratches by the expert was less than that by the non-expert.

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The goal of this research is the development of a learning system for the sheet-metal molding task carried out in automobile repair. In this study, the characteristics of expert's sheet-metal molding process for automobile repair were analyzed and compared with those with non-expert. Work time of "Hammering", "Other of hammering and judge", "Total" of expert was significant shorter than that of non-expert. The experts were used just one kind hammer at hammering process.

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The goal of this research is the development of a learning system for the coating and painting tasks carried out in automobile repair. In this study, the characteristics of skilled spray gun handling for automobile repair painting were analyzed and compared with those with little experience. The spray gun movements and posture of 10 participants were measured by using a motion capture system. The length from waist to spray gun of the experts was significant shorter than that of non-expert.

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