In recent years, aluminum alloys are expected to practical use for automotive industries to enhance weight reduction of car components. It is considered that a hundred kilograms weight reduction can improve a one kilometers/litter of the fuel consumption for a passenger's car. In the present study, a forming limit prediction method using a ductile fracture criterion with FEM analysis has been proposed. It is important that a numerical simulation can predict accurate forming limit in press forming of aluminum alloys. In this study, a FLD (Forming Limit Diagram) of 5000 series aluminum alloy was made by a finite element analysis with a ductile fracture criterion, which can capture the occurring of the localized necking of the materials. It has been clarified that a ductile fracture criterion only could be adopted in the range of uniaxial tension and plane strain tension. In the condition between plane strain tension and biaxial tension, it is difficult to adopt a ductile fracture criterion for predicting a forming limit of the materials.

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Numerical Equivalent Inclusion Method (NIEM) is a numerical scheme to calculate the stress distribution in an unbounded solid containing non-ellipsoidal inhomogeneities. The method is formulated by means of the Eshelby's equivalent inclusion method and the inhomogeneities are first replaced to the equivalent inclusions bearing equivalent non-uniform eigenstrains. Then the equivalent inclusions are subdivided into small polygonal (for 2D problems) or polyhedral (for 3D problems) inclusions bearing unknown uniform eigenstrains. Finally, the problem is reduced to a set of simultaneous equations with unknown eigenstrains. In this study, the results obtained by NIEM are compared with exact solutions of ellipsoidal inhomogeneities and the accuracy and efficiency of the method are discussed in detail.

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The Effects of the coat permeability and the expansion ratio of pattern on the mold filling of the molten aluminum alloy in the expendable pattern casting (EPC) process were investigated experimentally. An aluminum alloy plate was cast by the EPC process, and the filling time of the molten metal was measured for 3 kinds of pattern expansion ratios. The use of a high permeability coat or a high expansion pattern led to a larger melt velocity. The melt velocity does not increase in proportion to the coat permeability and the pattern expansion ratio. The experimental values of the melt velocity were compared with the calculated values based on the mold filling model by the previous study, and were in relatively good agreement with the calculated values for the case in which the coat permeability is under about 2. In the case the coat permeability is over about 2, the experimental values of the melt velocity were smaller than of the calculated values.

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In Japan Atomic Energy Agency (JAEA), a study of the thermodynamic feasibility of straight tube steam generator for Fast Breeder Reactor has been conducted. A coupled simulation system is being constructed which coupled the three dimensional simulation in sodium side with the multi-channel simulation in water side. The CFD code FLUENT was used to simulate the three dimensional flow in sodium side of SG by porous body model. The information exchange model between the sodium side and water side simulation codes was developed for the coupled simulation. A test simulation on the straight-tube steam generator system was carried out, and the accuracy of the coupled simulation model was confirmed.

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Abstract Earthquake is one of the most serious phenomena for safety of a nuclear reactor, especially in Japan. The behavior of nuclear reactor may be affected by the fluctuation of gas-liquid two-phase flow caused by the earthquake but not studied enough. In the project, bubbly or plug flow with flow rate fluctuation in a fixed horizontal pipe is studied experimentally. In this paper, the result on the bubbly flow under the flow rate fluctuation is shown. The flow was bubbly flow and/or plug flow in a horizontal circular pipe. The working fluids were water and nitrogen gas. The water was driven by a pump and the flow rate fluctuation was given by a reciprocating piston attached to the main flow loop. he behavior of horizontal gas-liquid two-phase flow under the flow rate fluctuation was measured by image processing and particle image velocimetry (PIV).

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In Japan Atomic Energy Agency, the detailed two-phase flow analysis code TPFIT has been developed to simulate and evaluate two-phase flow characteristics in nuclear systems [1]. In this study, a numerical simulation of bubbly flow in a vertical circular pipe was performed to validate the applicability of TPFIT code on bubbly flow simulation. By checking bubble distribution development in the flow direction, the calculation of the forces acting on bubbles was validated through comparing simulation results and experimental results from Lucas et al. (2005), who used wire-mesh sensor to obtain a high resolution of the gas fraction data in space as well as in time.

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This study aims at investigating the occurrence conditions and mechanism of geysering experimentally. So we investigated the flow in a vertical tube quantitatively by measuring temperature distribution among the tube and pressure in lower end of the vertical tube simultaneously. We also studied about the effect of heating condition on geysering by using different length tubes and two different heating apparatus: sheath heater which heat liquid directly and flexible heater which heat liquid indirectly.

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The aim of this study is to investigate that the diameter and the number of the flow channel, the position is what effect the pressure in lower plenum and quantity of liquid falling by using multiple flow channels, the smaller tube diameter. As a experiment condition, equipment consists of ten 1mm diameter narrow channels. We investigated pressure in lower plenum and quantity of liquid falling through an experiment and calculation. As a result, the following facts became clear. Pressure in lower plenum and quantity of liquid falling were decided by the number of glass tubes.

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The thermo-physical properties of Carbon Nano Tube Fluid (MWNT) are elucidated in order to consider the temperature dependency. The values of thermo-physical properties such as density, viscosity, specific heat, thermal conductivity and thermal diffiisivity are measured experimentally and quantitatively. The heat transfer of natural convection is also investigated in a horizontal enclosed rectangular container filled up with MWNT under the conditions of undersurface heating and upper surface cooling.

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This study is concerned about the pool boiling heat transfer and behavior of multi-walled carbon nanotube (CNT) suspension in water. Fourth different concentrations of 0.01% 0.05% 0.1% and 0.2% by weight of CNT dispersed with water were prepared and heating-test-section was used platinum thin line. The.test results show that the addition of carbon nanotube increases boiling heat transfer coefficients of the base fluids compared with water at same heat flux. The other side Critical heat flux of the aqueous solution is enhanced as compared to that of pure water it show up to 241% increase at the CNT concentration of 0.1 wt%.

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Bubble ring is a kind of stable gas bubble form in liquid where gas bubble is trapped in the vortex ring due to the centripetal force. In this paper, we compared the behaviors of bubble ring (two-phase flow) with those of vortex ring (single-phase flow). The gas bubble that launched downward and successfully formed a bubble ring went downward stably against the buoyancy force, while the gas bubble failed to form a bubble ring grew up instantly after launch.

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This paper reports the enhancement of the critical heat flux (CHF) using a porous microchannel. In available experiments to improve the cooling performance using a microchannel, the problem of explosive boiling is frequently encountered. To avoid this problem, porous metal was placed in the flow channel to construct porous-microchannel in the present work. In the porous microchannel, CHF increased almost linearly with increased values of the mass flux and the inlet subcooling. In consequence, higher improvement of cooling performance was achieved under high mass flux and high inlet subcooling conditions. In addition, it was found that pressure loss was stabilized in the porous microchannel. It was considered that the stabilization of pressure loss was mainly caused by the enhancement of large bubble condensation. It is necessary to perform detailed visualization experiment in the future studies.

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High power liquid metal targets for spallation neutron sources are being developed in the world. Mercury target has been installed at the Materials and Life-science Experimental Facility (MLF) in the Japan Proton Accelerator Research Complex, which will promote innovative science. At the moment of the proton beams bombard the target, pressure waves will be generated in the interface between liquid and solid metals due to the thermal shock.On the process of the pressure waves propagation, negative pressure induces the cavitation witch causes pitting damage on the inner surface of the target vessel. In the MLF, microbubbles injection into the flowing mercury is carrying out in order to mitigate the pressure waves. In this study, the effect of microbubbles on cavitation damage by microsecond-scale negative pressure was investigated through the vibratory horn tests in the bubbly water.

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The aim of this study is to develop an ultralow-head water turbine for an open channel, such as an irrigation channel, in order to effectively use hitherto unused hydropower energies. By focusing on a cross-flow runner, we eliminated the casing and used the application as a water turbine undershot-type cross-flow water turbine) for an open channel. We investigated the performance and internal flow of the water turbine with straight blades through an experiment and numerical analysis. As a result, the following facts became clear. At the turbine with straight blades, water area is narrowed at the outer and inner circumference of the runner, and torque and power are bigger.

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A hydraulic turbine for open channels does not need the incidental facilities for conducting water. It is applicable even if an effective head is comparatively low. However, because rotational speed is low, it has the tendency to enlarge. Therefore, the hydraulic turbine is fixed to a setting position. Authors proposed the new portable hydraulic turbine that utilizes the kinetic energy of an open-channel flow, such as a river and an irrigation canal. This hydraulic turbine is a structure which added collection device to the axial flow runner, and increase in an output is aimed at by making a flow collect and accelerate. In this study, characteristics and flow fields of the runner simple substance, and the complex of the runner and collection device which differ in airfoil and number of blades are clarified by numerical analysis. Furthermore, effects of airfoil and number of blades exerted on performance of this hydraulic turbine are clarified.

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A hydraulic turbine for open channels does not need the incidental facilities for conducting water. It is applicable even if an effective head is comparatively low. However, because rotational speed is low, it has the tendency to enlarge. Therefore, the hydraulic turbine is fixed to a setting position. Authors proposed the new portable hydraulic turbine that utilizes the kinetic energy of an open-channel flow, such as a river and an irrigation canal. This hydraulic turbine is a structure which added collection device to the axial flow runner, and increase in an output is aimed at by making a flow collect and accelerate. In this study, characteristics and flow fields of the runner simple substance, and the complex of the runner and collection device which differ in number of blades are clarified by numerical analysis.Furthermore, effect of number of blades exerted on performance of this hydraulic turbine is clarified.

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Ocean energy recently attracts people's attention as one of the renewable energy resources and there is abundant ocean energy around Japan. But we cannot utilize them in practical use due to typhoon problems. For solving the problems, we have developed a compact, low-cost but flexible wave power generator which can work under the motions of multi-degree of freedom. In this study, we experimentally analyze the motion of the mock-up generator under the artificial wave in the small-scale tank. We focus on the effect of density and inertia moment of the mock-up generator.

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By applying an inverse tapered blade to a small wind turbine, it is shown clearly experimentally that the performance at a low rotational speed region improves. However, the details of the performance improvement mechanism are not clear. The purpose of this research is to clarify the performance and flow field of two kinds of horizontal-axis propeller type wind turbines having different rotor plane shape. Therefore, the rotors which have the tapered blades which become small as chord length goes to a tip, and the inverse tapered blades which become large as it goes to a tip were investigated by numerical analysis. As a result, the following facts became clear. The inverse tapered blade has a power coefficient larger than the tapered blade, and the peak shifts to a low tip speed ratio side.Moreover, the inverse tapered blade has a load larger than the tapered blade at a tip.

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This paper describes aerodynamic design optimization of wind turbine rotor blades which considers power productions and aerodynamic loads. An existing computer program, which is a multi-objective genetic-algorithm based optimization method, provided part of the foundation for this research. The objectives were selected to study the effect of blade length for annual power production and load on structural components. We showed that even in a load equivalent condition, the longer blades were effective for increase of the quantity of annual generation and weight-saving.

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A dual-fuel diesel engine with port-injected natural gas as the main fuel has a problem with high unburned hydrocarbon (UHC) emissions at low load. In this paper, chemical kinetics analysis was carried out in order to clarify the effect of natural gas and diesel fuel concentration on chemical reactions and species concentrations. The results show that H202 loop mechanism has an important role for heat release which transfers from low temperature xidation to high temperature oxidation. Natural gas concentration has a small influence on heat release, while diesel fuel concentration has a great influence on it.

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Throat tap nozzle of ASME PTC 6 is widely used in engineering fields, however an experimental discharge coefficient is not coincident well with it this standard. The purpose of this paper is to investigate the behavior of the discharge coefficient for high Reynolds number up to 1.4x107 in experimental. The discharge coefficients are measured for several nozzles with several tap diameters in Reynolds number range from 2.4x105 to 1.4x107 using calibration facilities in NMIJ. Experimental results show that the discharge coefficients depend on the tap diameter and the deviation between the experimental results and the reference curve of PTC 6 is 0.75% at maximum.

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This study is aimed at making a visualization measurement of the temperature and the velocity field of the liquid storage tank. And I was examined quantitatively for the correlation characteristic of temperature and velocity field in the tank. I was used to PIV velocity distribution measurement in the measurement method. And I was used to LIF temperature field measurementAs an initial experiment, I visualize measurement in the tank water temperature uniformity.The experimental results, a simple flow field water flows to the outlet near was calculated.In the future, I will make the temperature stratification in the tank, and to target the visualization of the flow characteristics of the spill.

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Numerical simulation method to analyze unsteady thermal-hydraulic phenomena in the upper plenum and the hot-leg piping system in Japan Sodium cooled Fast Reactor (JSFR) has been developed. Flow-induced vibration (FIV) in the hot-leg piping with the short elbow (curvature radius corresponds to diameter) is mainly targeted in this study. Numerical simulation model of the hot-leg piping systems with the short elbow integrated into upper plenum full domain were constructed. Through the numerical simulation with the lull sector model, applicability of numerical models and mesh arrangement for transient calculation were confirmed and unsteady flow phenomena in the plenum and piping system were successfully analyzed.

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The thermo-physical properties of magnetic fluid (MSG-W11) were elucidated in order to examine its temperature dependency under magnetic field. Heat transfer by natural convection was also investigated in a horizontal enclosed rectangular container filled with the magnetic fluid which was heated at the lower surface and cooled at the upper surface under magnetic field. Various thermal properties of the magnetic fluid and their temperature dependency were clarified in the present research. It was also found that the heat transfer coefficient coincides well with the onventional heat-transfer correlation of natural convection heat transfer in a horizontal enclosed rectangular container by applying the values of thermo-physical property obtained in the present research.

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We have developed a small and thin maglev ventricular assist device which enables to implant under the thorax muscle layer. Two radial degrees of freedom of a levitated rotor and its rotation are actively controlled by electromagnets constructed on a stator. An Axial position and tilt motion are stabilized passively with self-restoring characteristics of magnets. The spiral groove bearing (SGB) was developed to stabilize the axial direction of the rotor. The SGB to avoid rotor touchdown set on the rotor surface. A load carrying capacity was calculated to determine dimension of the SGB. And, an evaluation system was developed to evaluate the performance of the SGB. The maximum load carrying capacity was calculated as 2.2 N with a bearing clearance of 10μm. Groove depth, groove angle and ratio of ridge width to groove width were determined as 55 μm 7 degrees, and 1.0 respectively.

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A miniaturized magnetically levitated axial flux motor which can actively control 5-dgrees of freedom (5-DOF) of impeller postures has been newly developed for a paediatric ventricular assist device (VAD). The developed motor consists of a top stator, a bottom stator and a levitated impeller which is set between the both stators. A novel 5-DOF control theory with a double stator mechanism was proposed. A prototype motor which has the outer diameter of 28 mm and the height of 41 mm was developed in order to verify the feasibility of proposed control theory. The static characteristics of the axial attractive force, the rotating torque, the radial attractive force and the restoring torque were examined. The developed motor produced sufficient suspension force and the rotating torque required for the paediatric VAD.

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The tactile-force function is high important on development of humanoid robot and human interface because it leads to the improvement of safety and operability. Human tactile mechanism is due to the tactile receptors. For the reason that it is possible to regard the tactile receptors as a mechanical sensor, those researches focused on the tactile receptors are being performed them. Thus, we have developed flexible tactile sensor that silicone rubber embedded in diaphragm strain gauges with the aim to detective a wide range of distortion and a small number of channels. Diaphragm strain gauge is the strain gauge which resistance element is disposed on the circumference. This is suitable for the detection of the wide range of distortion because the axial direction of the distortion is not limited. We performs a load test to verify the detection of distortion quantitative corresponding to the load, hardness tests using three different hardness materials, and examined the efficacy of the sensor developed.

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In vitro antithrombogenic testing is a useful pre-evaluation for ex vivo test of a continuous flow pump as an artificial heart. In order to establish this testing, it is important to make clear the relationship between activating clotting time (ACT) and shear rate for the thrombosis. In this paper, we describe a quantitative evaluation of thrombus formation due to ACT and shear rate using a rheometer. The ACT of 250 s was suitable for the in vitro thrombosis evaluation under shear rate at between 100 and 2,880 s_1 by a rheological approach, this ACT vale is applicable for an in vitro antithrombogenic testing with a mock circulation for a continuous blood pump.

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The performance of centrifugal blood pump with a monopivot bearing is affected by hydraulic force on the impeller since the impeller is supported at a single contact point. We investigated the impeller stability against the hydraulic force. First, we calculated the hydraulic force on the impeller and the hydraulic force moment on the impeller around the ento- of the pivot by computational fluid dynamics (CFD). Next, we measured the clearance gap between impeller and casing. As a result, it was found that the hydraulic force moment about y axis was larger than that about x axis. Also, it was found that the impeller tilt around x axis was laiger than that about y axis.However, the clearance gap between impeller and casing was kept large enough.

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We have developed a hydrodynamically levitated centrifugal blood pump as a bridge to decision pump. However, since the bearing stiffness of the hydrodynamic bearing is small, the bearing gap tends to become narrow. The purpose of this study is to evaluate the improvement of the impeller levitation performance due to the effect of the thrust bearing geometry with spiral groove on impeller levitation performance in a hydrodynamically levitated centrifugal blood pump. We compared the geometric models that have different groove width. The numerical analysis was performed in order to calculate the bearing stiffness. The impeller levitation performance test was conducted using a mock circulation loop and a laser focus displacement meter. As a result, it was found that the sudden contraction model achieved an improvement of the impeller levitation performance in a hydrodynamically levitated centrifugal blood pump.

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An active magnetic bearing system can support rotating shafts without any mechanical contact. Therefore it has been used such as an ultra-low temperature, a vacuum, and a clean environment. To realize the downsizing of the system and the high-speed rotation, a 2-axis and 5-axis self-bearing motor has been proposed. In this paper, a consequent-pole type self-bearing motor is proposed. It is possible to control the rotor position without the information of the rotating angle. The radial control forces and cogging torques are analyzed using 3 dimensional finite element method. The results show the improvement of the error angle and the cogging torques by changing the model shapes.

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Brachial plexus palsy is a functional disorder which needs upper limb orthosis, and a Erb's plexus paralysis is also a disability whose shoulder and elbow cannot be moved although whose wrist can be moved. Therefore if their shoulder and elbow can be moved by the active orthosis, their ADL will be improved dramatically. Authors are developing an active upper limb orthosis that can be controlled by EMG generated by movement of their wrist. The objective of the research is to develop a mechanical part of the orthosis. The orthosis has three degrees of freedom, flexion of shoulder and elbow, and rotation of upper arm. Two motors are used to achieve the movement, the first motor flexes shoulder and elbow by pulling the wire connected to the forearm part and the second motor rotates the upper arm. The movement of houlder, elbow and wrist were measured and compared with the result of simulation. The measured trajectory of flexion movement was almost same as the result of simulation. However, that of internal rotation was different from the simulation, as the shoulder joint was simultaneously flexed during the rotation.

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Seated posture on the wheelchair is important, because it may cause swallowing and respiratory difficulty, develop a pressure sore and affect motor performance. Although systems that can measure angles of seated posture that are defined by the international standard ISO 16840-1 have been introduced, many points to be improved are remained. The developed system aims to measure the seated posture in three dimensions by recognizing numeric markers pasted on the subject from images captured by stereo video cameras. The marker recognition program using a template matching method was developed by MATLAB. Cases when the markers were pasted on the board, mannequin and the subject were evaluated. When the markers were pasted on the board, all markers can be recognized although the distance was changed from 1.5 to 6 [m], and the board was inclined backward and forward, right and left 30 [deg] and rotated 80 [deg]. And from the result of mannequin and the subject, all markers can be detected around 10 [deg] of backward, forward bending, 15 [deg] rotation and left lateral bending cases.

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We had developed a wearable leg support system, Manipuleg-2, that the wearer can control his or her paralyzed leg via a control lever attached at his or her shoulder. In this paper, we have proposed a novel method of controlling the leg support system, that does not use levers, but uses a camera to detect the wearer's command. We have shown that the leg support system could be driven by operating the control grip.

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In this paper we have proposed the method of enhancing the stability of standing position using visual substitution or tactile sense of foot sensation . Because a person with lower paralysis put on the powered exoskeleton at the leg, it is rather difficult to keep the standing position. This is because the wearer does not have his or her foot sensation, and cannot know the own ZMP directly. Therefore, we have developed the tactile device, and shown the effectiveness of visual feedback and tatile of ZMP information to the wearer.

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In this paper, we propose a pair of step-climbing units that can be set on a standard manual wheelchair. The user is such a person who has no disabled upper limbs and is able to raise casters attached in front of the wheelchair by him/herself. This system can support the independent life of the user. Each step-climbing unit comprises two actuators and has two degrees of freedom: a prismatic joint and a rotational joint. We mainly discuss the motion of walking up a slope using this system, and experimental results of climbing a 30 cm step with a pair of mobile slopes confirmed effectiveness of the design.

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In this study, we developed a system to analyze pedaling mechanism of cycling. The system evaluates each joint torque of lower limbs. The joint torque was calculated with Newton-Euler inverse dynamics. First, pedaling force was measured by new designed biaxial load cells which were applied to between pedals and shoes. This load cells were able to measure magnitude and direction of pedaling forces of both pedals, respectively. To convert the direction of the pedaling forces, pedal angle was calculated by the link mechanism of lower limbs. The length of the each element of lower limbs, length of crank and position of greater trochanter were supposed to be given as constant parameter for computational calculation. Moreover, the model was divided into 3 segments: thigh, lower thigh and foot. In Each segment, equation of motion was solved to calculate the joint torque. Therefore, evaluation method of pedaling mechanism of cycling was proposed.

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Being possible to control power assist suits by myogenic potential to have an operator's aim of motion, it is lost that the time difference between beginning time of the power assist and the actual operator's motion. Thereby, operators will be possible to perform work without a feeling of strangeness. In this study, we developed an experimental device for measuring the variation of motion velocity of an elbow when change in the load of elbow joint, and calculated integrated EMG (iEMG) and Mean Power Frequency (MPF) from surface EMG (sEMG) of biceps brachii muscle measured during the motion, it was discussed about whether discrimination of the force and the velocity of the motion are possible from these two characteristic values. Form the result, it is possible to discrimination of the force and the velocity of the motion by measuring the iEMG, fine operation could not be discriminated and the accuracy was influenced by flexion angle of an elbow.

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We equipped an electric hand prosthesis with a fingerpulp and measured the contact area of the sphere grip. Then 3 types of rubber sponges which were urethane-based rubber, natural rubber and ethylene propylene rubber were selected. Each of these materials was categorized into low hardness and high hardness. When we made a comparison to the human hand, the result showed that the low hardness urethane-based rubber (hardness 5) was the most close in term of contact area. The deformation characteristic was considered similar due to the gelatinous of the fingerpulp and low hardness urethane-based rubber.

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We propose a technique to prevent the migration using the biomedical tissue adhesion technology. In this paper, heat characteristic of stent and adhesive strength between stent and tissues were measured. The tissues were porcine arteiy and esophagus. Frequency, input current, and measurement time were 600 kHz, 3.0 A, and 180 s, respectively. As a result, the time that porcine artery and esophagus temperature reached at 80 ℃ were 136 s and 68 s, respectively. 0.02 MPa can be obtained as adhesive strength for both of them.

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We have developed a method that allows biological tissues to adhere together with minimal invasion by delivering integrated low-level energies such as heat, pressure, and vibration. The adhesion mechanism was investigated by observing collagen fibril's change under the influence of heat and pressure by atomic force microscopy and scanning electron microscopy. When collagen fibrils were treated with heat at temperatures above 63℃ in dehydrated nvironment, some collagen fibrils with diameters above 1000 nm were observed by atomic force microscopy. Furthermore, when application of pressure of 2 MPa and application of heat were applied simultaneously on collagen fibrils at temperatures above 63℃ in dehydrated environment, aggregation of collagen fibrils was observed by scanning electron microscopy. Since thick collagen fibrils have higher mechanical strength, application of pressure of 2 MPa and application of heat at temperatures above 63℃ applied on biological tissues were expected to lead to adhere biological tissues together tenaciously by proposed method.

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To evaluate the heating distribution, human body phantom which is equal to electrical characteristics of human tissue is important. In this paper, in order to facilitate insertion of the probe in the phantom, a prototype gel phantom (waist part) is investigated. Thermal characteristics and conductivity of gel phantom in the cylindrical acrylics case were evaluated. As a result, conductivity of the phantom is 0.613 S/m, which is equal to the conductivity of the human muscle at 8 MHz. Therefore it becomes equal to a theoretical value. Temperature rise at center between the electrodes was 5.6℃. These results are in good agreement with theoretically value.

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The phenomenon that the particle or the bubble is captured at nodes of standing wave by sound wave is widely known. Recently the phenomenon is theoretically clarified, and acoustic levitation technology is being established. If the acoustic levitation technology can be applied to the abrasive machining for control of the abrasive movement, an indispensable rotational and liner movement mechanism for the traditional abrasive machining become unnecessary, and the complicated machining in access, for example; the internal finishing of a tube, is able to be realized. In this study, we aim to proposal of a new method the abrasives with acoustic levitation, and develop a new polishing process that excludes machine movement mechanisms of driving. I In this paper, the equation and condition of acoustic levitation is derived and the twin transducer machine is developed.

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Recently, it is important to carry out optical control of the neutron beam. There is a neutron mirror in the method and electro-less plated NiP surface is raised as a material candidate. This report describes the result of an xperimental consideration about the polishing characteristics change of electro-less plated NiP surface. Mirror finishing xperimented to using electro-less plated NiP surface and it changed polishing conditions and the material characteristics of the substrate.

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In this research, composite planting has studied using the improved trivalent chromium bath with lower concentration. It is known that various kinds of particles can be introduced into the chromium layers from trivalent chromium baths, though composite plating is generally difficult by the hexavalent plating bath. So, alumina particles were added into the improved trivalent chromium bath, and composite layers were electrodeposited, dispersing the particles uniformly in the bath. The properties of the composite layers obtained were examined and it was found that the alumina composite plating has higher wear and abrasion resistance than the non-composite Cr-C[III] plated layers.

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In this paper, a new GPU based algorithm is proposed for detecting collisions between solid objects. The proposed algorithm is fast, precise, and applicable to large and complex objects with huge number of polygons. In our broad phase collision detection, a culling program based on the lattice structure is executed on GPU to efficiently exclude apparently non-colliding polygons. In the following narrow phase collision detection, parallel processing capability of GPU is used for detecting mutually penetrating polygons. A sample program is implemented and tested with complex examples.

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Distance field is a voxel representation solid model with the distance property. Each voxel of the model has a distance to its closest model surface. In this paper, the authors propose a new visualization method of the thickness of a solid model based on the distance field of the model. For each vertex of polygons of the model, the author's method determines the largest sphere inscribing the model surface at the vertex. Its diameter corresponds to the thickness of the model at the vertex. The radius of the sphere can be derived by tracing the distance field along a half line inwardly starting from the vertex. An experimental system is realized and some computational experiments are performed.

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The accuracy improvement of the molds is recently more and more required for the precise molding of aspherical lenses. In this study, the characteristics of the aspherical lens mold polishing by a rotary tool had been described.

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ELID is technique that it electrolyzes the wheel surface during processing for dressing. This method came to enable the minute abrasive wheel to use. However, in late years the more environmentally friendly processing techniques are required. Therefore, non-chemical solution type grinding fluid was developed. Our laboratory try to pair non-chemical solution type grinding fluid with micro bubble to make new non-chemical solution type grinding fluid. In this report, we researched property of new non-chemical solution type grinding fluid and electrolyze dressing property.

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