We developed a prototype of a compact ECMO (Extra-Corporeal Membrane Oxygenation) system for the neonates with respiratory failure. The system has the following specifications: (1) A single lumen catheter is used for blood withdrawal and infusion. (2) Blood is driven by a diaphragm pump, where the blood flow is controlled by a microcomputer. (3) Activated coagulation time is controlled by infusion of not only anticoagulant (heparin) but also its neutralizing agent (protamine) in order to avoid bleeding caused by excessive dose of anticoagulant. (4) The system is small and easy to operate. This system is less invasive and easier to operate than conventional systems. Its potential application as a respiratory support system was evaluated in animal experiments. The system offered favorable gas transfer and easier operation with less invasion. The system was considered applicable to respiratory aid for neonates.

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A new grinding method for contouring formed cutters with high accuracy is proposed. Based on the new method, a simultaneous three-axis NC contour grinding device with simple composition was developed. The device consists of an X-Y cross slide which performs linear movement and a rotary table which performs rotating movement, and is numerically controlled by a personal computer. The advantages of the device are as follows : (1) The rotating accuracy of the rotary table has no influence on the contour grinding accuracy of a workpiece. (2) The wear of a grinding wheel can be reduced, so that the number of truing of a wheel can be decreased. (3) No operations of relieving of a cutter are needed. Two types of formed cutter were ground with the new device, and then the form accuracy of these cutters was measured with a three-dimensional coordinate measuring machine. The result showed that the accuracy of one type was ±5 μm and the other was ±6 μm.

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The beginning and ending position on the working surface of grinding wheel when involute helical gear is ground with rack-tooth worm wheel are geometrically analyzed. The effects of operating parameters on the grinding mechanism of gear tooth surface are discussed. Moreover, it is confirmed that the tendency of the experimental results agree well with that of the analytical results. As the results, the following facts are clarified. (1) The ending position on the working surface of grinding wheel is the generating position of gear tooth profile in leading side and is behind it in trailing side. (2) The working length of grinding wheel, when infeed of wheel is large and feed of workpiece is small, is longer in leading side than in trailing side. (3) The wheel wear is apt to increase when the working length is shorter.

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This paper deals with the development of automatic measurement system of growth of plant for multi-items, which are photosynthetic rate, weight changing rate and area of leaves of plant.To measure these items of the test plant, Pakutyoi, it is proved that the system can run satisfactorily. It is also proved that area of leaves can be monitored. by image processing technique with the use of two kinds of interference filters. It is found that the fact that some effects of past history of the plant affect the data of photosynthetic rate suggests that it is not recommendable to change the circumferential conditions in a short time.

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This paper describes a generalized method of cutter-direction control using DDA (Digital Differential Analyzer) algorithms. The method is applicable to cutting out two dimensional arbitrary shapes with high accuracy. The cutter path generation process requires a method for moving the cutter along the lines of the figure and for keeping the cutter tip tangent to lines of the figure. The algorithm is capable of generating equations for lines, arcs, ellipses, and arbitrary shapes. For complex shapes, the DDA algorithm generates the desired functions which represent the lines of figure and the tangent lines are generated from points input by a user. From this information, the motor control parameters for cutting these shapes may be easily obtained.

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This paper describes the adaptability of a newly proposed mask-and-wafer alignment technique for semiconductor processing. This new single and double-pitch dual grating method uses gratings as alignment marks. Shape change in gratings due to processing and the consequent effect on gap and lateral displacement detection signals are discussed both theoretically and experimentally. When a gap detection signal has a sharp peak at a gap setting point where the aperture ratio is from 0.3 to 0.4, and when a lateral displacement detection signal has a simple triangular waveform where the aperture ratio is from 0.5 to 0.8, and the step width ratio is from 0.4 to 0.6, a high gap and lateral displacement detection accuracy is achieved. These theoretical calculations agreed well with experimental results. Transparent films such as resist, SiO₂, and poly-Si, and opaque films such as Al, which are deposited on a wafer grating mark during processing, decrease signal intensity because of the interference that results from the thickness of their multiple films. They also make the grating edge round, but they hardly change the signal waveform. High reflectivity films such as Al only degrade the lateral displacement detection signal waveform due to multiple reflection between the mask and wafer. As this makes detection accuracy low, decreasing reflectivity is necessary.

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Recently, several types of new polishing methods using a magnetic fluid have been developed and fundamental studies have been carried out. This paper describes an application of the magnetic field-assisted polishing to a spherical surface. This method is devised on the basis of the electro-magnetic behavior of the magnetic fluid. As a polishing test material, single crystal LiNbO₃ is examined. It is a man-made and hard-brittle material, and it is machined previously to a spherical surface 50mm in radius of curvature by diamond turning. The experimental results show that a surface roughness of 0.01 μm Rmax can be easily obtained when colloidal silica is used as a polishing abrasive. And it is clarified that the magnetic field strength is closely related to the pressure and the removal rate. Therefore, in the case of finishing curved surfaces precisely, the magnetic field distribution must be uniform.

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A hot machining technique using plasma jet heating has been employed to improve the machinability of glasses and engineering ceramics such as Pyrex, mullite, alumina, zirconia and silicon nitride. Plasma heating is aimed not only at reducing the hardness of ceramics but also at changing the chip formation from discontinuous to continuous. The turning forces markedly decreased as the workpiece was heated to temperatures above 1050°C in the case of silicon nitride. Increased heating temperature changed the segmented chips produced in ordinary cutting into continuous ones, accompanied by a better finished surface with less defects. Tool wear was also decreased by means of hot machining: e.g. by a factor of 8 in turning silicon nitride with a diamond tool. However, the application to alumina and zirconia did not show sufficient improvements in machinability.

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In this study, processes of surface damage of ceramics ground with diamond grinding wheels of various bonds have been investigated experimentally and theoretically. There exist microcrack layers in the ground surface, and voids are formed below the layers. There is a relation between bond type and thickness of both the microcracks and the voids. So the purpose of this paper is to describe the influence on the surface damage of ceramics ground with diamond grinding wheels of various bond types. All of the diamond wheels are manufactured with blocky grains, in order to investigate the influence by bond type in particular. It was found that the thickness of both microcracks and voids became smaller with wheels of metal bonded, vitrified bonded, resinoid bonded, and that the more diamond grains wore, the deeper the depth of both microcracks and voids are formed.

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In this report, the working surface just after dressing the resin bond CBN wheel was examined by observing the behavior of abrasive grain and measuring the cutting edge distribution in dressing process for several conditions by means of WA stick methods. The main conclusions obtained are as follows : (1) The chip pocket is gradually produced in dressing process. Instantaneously, the breakage and the release from bond of CBN grain occur and the new grain appears from within bond. The percent of the release grain and the new appearance grain differs with each dressing condition. (2) The average depth of chip pocket increases with the increase of the consumption of WA stick and tends to finally coverage to a constant value. (3) The cutting edge distribution becomes coarser for more consumption of WA stick and heavier dressing condition. (4) The cutting edge distribution becomes closer by executing the re-truing operation just after dressing. By using the close cutting edge distribution can be adjusted over a wide range by controlling the conditions of dressing and re-truing.

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In this study, cutting tests with CBN tools are performed on chromium-molybdenum steels of various hardnesses in order to clarify the cutting characteristics and the influence of the workpiece hardness on the tool life of CBN tools in the turning of steels. Three types of CBN tools (CBN contents of 30%, 60% and 90% respectively) are tested in comparison with P 10 carbide and white ceramic tools. The flank wear and the amount of deposited metal on the tool flank are observed by using SEM and EPMA. The results obtained are as follows : (1) CBN tools are able to cut very hard steels of over HRC 60 which can not be cut with conventional carbide tools. (2) The flank wear of CBN cutting tool is affected by CBN content, where the CBN cutting tool of 60% CBN content indicates the longest tool life. (3) The flank wear of CBN cutting tool is mainly affected by the wear characteristics of the bond material of the tool.

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This paper deals with the effect of the factors governing polisher surface temperature, which is strongly correlated with stock removal rate, on the mirror polishing of Si wafers. The factors investigated here are the coefficient of friction between the polisher and the Si wafer, the temperature of the polishing reagent, and the polishing area ratio, which is defined as the ratio of the total wafer polishing area on a polisher relative to the effective area of the polisher. The increase of these parameters promotes the chemical reaction between the Si wafers and either the polishing reagent or the polisher, and results in improving the stock removal rate. The polisher surface temperature, indicative of the chemical activity, can be easily controlled by the temperature of the polishing reagent, and as a result a stock removal rate more than 4 times higher can be achieved without deterioration in quality of Si wafers.

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This paper describes an experimental investigation of the cutting of Al-Ni alloys and tool wear mechanism to diminish severe tool wear in hypereutectic Al-Si alloys. These alloys contain softened second phase particles (intermetallic compound Al₃Ni, HV=650) in comparison with primary Si hard particles (HV=1560) in hypereutectic Al-Si alloys. Summary of the results are shown below. (1) With increasing in Ni content in the alloys, number and area percentage of intermetallic compound particles increase. The cutting force components decrease gradually and the surface roughness become worse in higher Ni contained alloy. (2) The machinability and cutting temperature of Al-Ni alloys are determined to be the nearly same as those of hypereutectic Al-Si alloys. (3) Crushed and/or fine grained particles in Al-Ni alloys are almost not observed in cutting and torsion test due to the enriched plasticity of the matrix. (4) Tool wear of carbide tools in cutting of Al-Ni alloys are hardly observed within this work. These facts are attributed to smaller matrix force restricted for the particles and less frequency of mechanical scratching by hard particles for tool flank, in comparison of those of hypereutectic Al-Si alloys.

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This report describes a method for the estimation of the curing process of thermosets used for plastic-encapsulated ICs. This method consists of a thermal analysis by the differential scanning calorimetry (DSC) and an analysis of non-stationary heat conduction using the finite element method (FEM) coupled with the rate of heat evolution. The formula of the rate of heat evolution deduced from the DSC data could not be directly applied to the analysis because the thermodynamic conditions in DSC were not exactly the same as that in molding process, so that a state-dependent variable α were newly introduced to correct the formula. The temperature profiles at four positions in the cavity during cure were measured with CA-thermocouples. The α was determined by inverse solution of the FEM with the measured temperatures. The obtained variation of α is expressed by a function of time after the end of filling process and the conversion of resin. With making use of the α in the calculations of temperature, the predicted temperature profiles compare reasonably well with the experimental results. It is found that this method gives propriety of curing analysis including the effect of process parameters of α to estimate the solidification front.

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The compositions of hot phosphoric acid between 200 and 320°C under refluxing and nonrefluxing (open) conditions were studied by means of the paper chromatography and the colorimetric analysis. The etch rates of various ceramics were measured in the acid under several conditions. The composition of the nonrefluxed open acid varied with time due to dehydration and condensation. On the other hand, refluxing water vapor during heating provided a good etching condition in which the temperature and composition of the acid were maintained constant. Under refluxing condition, two types of phosphoric acid were available ; a boiling acid and an equi-composition acid. In the refluxed acids, the etch rates of ceramics were increased with temperature. Alumina ceramic had an etch rate of several μm/min at temperatures above 250°C in the refluxed boiling acid. The etch rates for the equi-composition acid was lower than those for the boiling acid at the same temperature, due to a higher degree of condensation for the equi-composition acid. The etch rate of alumina ceramic was also increased with the concentration of orthophosphoric acid.

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This paper proposes a method for representing Free-Form Primitives with blending surfaces by the CSG modeling. In this method a general sweeping technique is applied to generate the Free-Form Primitives as follows a closed curve, which is defined on a 2-D sectional plane, is swept in 3-D space along a 3-D curve to generate a swept volume. The method allows the 2-D closed curve to change geometry or dimension during the sweep. Since the 2-D closed curve which is in the middle of the sweep is represented by blending two static 2-D closed curves at the start and end positions of the sweep, the enveloping surface of the 2-D closed curve during the sweep becomes an entire blending surface. A swept volume with the blending surface consists of a set of space points which are inside or on the 2-D closed curve from start to end of the sweep. A Free-Form Primitive is generated as a result of a swept volume, and is used for rounding corners such as edges or vertices, or joining two disconnected solids. Blending functions for representing the 2-D closed curve are derived mathematically, and how to define a swept volume with a blending surface by an implicit function in 3-D orthogonal coordinate system is discussed.

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In this study, the following conclusion has been obtained by introducing the SN technique into evaluation of the polishing of silicon wafer and examining the reason-ability to use characteristics value for determining an optimum machining condition. It is found that evaluation of an optimum machining condition according to the minimizing characteristic and aiming characteristic is controlled by the confidence limit and error to the confirmation test is considerably small where the evaluation is applicable as an evaluation characteristic value. The experiment described in this paper confirms that mathematical tool for an evaluation of the optimum machining condition can be applied in the skillful polishing process domain. And also, analytical and experimental considerations on the polishing accuracies and performance were accorded with explanation from the polishing mechanism.

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