Sample records for zenmen shototsu jiko

  1. Accident reconstruction to analyze impact of injured drivers during the collision. Ankle fracture in the car-to-car offset frontal collision; Join no jusho jokyo ni kansuru jiko saigen. Joyosha doshi no offset zenmen shototsuji no ashi kansetsu kossetsu

    Sakurai, M. [Japan Automobile Research Institute Inc., Tsukuba (Japan)


    An accident reconstruction test of car-to-car crash was conducted in order to analyze the impact on the driver in the offset head-on collision. The ankle fracture of the driver resulting from the accident was examined with the test results and the accident data. The test results of the car-to-car crashes indicated that the belted driver`s ankle would have fractured in the early stage of the crash. The detailed information from the accident data, especially the cars` interior deformation and the driver`s X-ray photographs, was also very important in analyzing injury mechanisms of the ankle/foot region. The above results suggested an injury mechanism that the ankle joint fracture was due to dorsiflexion and valgus resulting from the impact and intrusion of the toeboard in the early stage of the crash. 12 refs., 11 figs.

  2. Completion of petroleum reserve base in the eastern part of Tomakomai. Tomakomai tobu sekiyu bichiku kichi zenmen kansei ni tsuite


    The construction of a petroleum reserve base in the eastern part of Tomakomai (called Tomakomai Base hereafter) was started in 1981 as a part of the national petroleum reserve business, and the base of 2.74 million{sup 2} was completed in November 1990. This report introduces the whole aspect of the base; from the selection of its location to the construction processes and the facilities. The Tomakomai Base is a corporation capitalized at 10 billion yen and main stock holders of the corporation are the Japan National Oil Corporation and petroleum corporations. After some modifications during construction, 57 tanks (114.8 thousand kl {times} 55 tanks, and 42.7 thousand kl {times} 2 tanks) of 6,400 thousand kl capacity were completed. The base is conveniently located on the coast 20km from the Chitose Airport. The climate here is comparatively warm for Hokkaido, and it snows little. The construction work went on smoothly with the unstinted cooperation of local organizations, one city and three towns. With the consolidation of the life environment and the work environment of the workers there, a continuous 1200 hour record of no accidents was attained. 5 figs., 2 tabs.

  3. Floor-supply displacement air-conditioning system; Zenmen yuka fukidashi kucho system ni kansuru gijutsu kaihatsu

    Takebayashi, Y.; Nobe, T. [Shimizu Corp., Tokyo (Japan); Hatanaka, H. [Nitto Boseki Co. Ltd., Tokyo (Japan); Tanabe, S. [Waseda University, Tokyo (Japan)


    This development is proposing an alternative air-conditioning method, 'floor-supply displacement air-conditioning system'. The idea comes from the principle of displacement ventilation originally, using breathable carpet tiles laid over a perforated raised floor system. In this system, fresh cool or heated air are supplied at very low velocity throughout the carpet tiles. This system has been applied to 25 buildings and total floor area reached 10,000m{sup 2}. (author)

  4. Annual energy review-1996; 1996 nen ni okeru juyona energy kankei jiko



    This paper reviews the important items concerned with energy in 1996. Primary energy supply sums to 529times10{sup 13}kcal increasing by 2.4% over last year. The growth rates of demand over last year are 2.5% in industry use, 3.7% in transport use, 3.7% in home use, and 1.3% in business use. On R & D trend of use technologies of energy resources, the following are described: (1) Petroleum: resource exploitation, transport, stock, refining, and petrochemistry, (2) Coal: resource exploitation, coal structure and property, processing, transport, liquefaction, gasification, carbonization, tar industry, carbon industry, and coal ash utilization, (3) Natural gas: resource exploitation, transport, storage, and conversion technology, (4) Natural energy: hydraulic, solar, geothermal, wind power, oceanic and biomass energies, and (5) Others: waste resources, hydrogen and alcohol. On R & D trend of energy conversion technology, combustion theory, boiler, engine, thermal energy system, and high-efficiency power generation technology are described. Environmental problems and their protective technologies are also described

  5. Autosolvent effect of bitumen in thermal cracking; Netsubunkai hanno ni okeru bitumen no jiko yobai koka

    Mikuni, M.; Sato, M.; Hattori, H. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology; Nagaishi, H.; Sasaki, M.; Yoshida, T. [Hokkaido National Industrial Research Institute, Sapporo (Japan)


    Tar sand bitumen is petroleum-based ultra-heavy oil, and has a great amount of reserve like coal. However, there are still a lot of problems for its highly effective utilization. This paper discusses whether the light components in bitumen show independent behavior during the thermal cracking of heavy components, or not. Solvent effect and reaction mechanism during the thermal cracking are also derived from the change of their chemical structures. Athabasca tar sand bitumen was separated into light and heavy fractions by vacuum distillation based on D-1660 of ASTM. Mixtures of the both fractions at various ratios were used as samples. Negative effect of the light fraction on cracking of the heavy fraction was observed with dealkylation and paraffin formation Polymerization of the dealkylated light fraction to the heavy fraction was suggested due to lack of hydrogen in the thermal cracking under nitrogen atmosphere, which resulted in the formation of polymer. 3 refs., 6 figs.

  6. Accident of heavy oil spilling into rivers; Juyu kasen ryushutsu jiko

    Inoue, H.


    A case of accident of heavy oil spill was described for the safety control of a thermal power station of N plant. One unit of 2000kl receiving tank and a pump have been installed in the heavy oil base, and the oil has been transferred to the service tank of the plant a few hundred meters away. The heavy oil was found leaking and gushing out from the outlet piping of the pump. The pump was stopped and the outlet valve was closed, but the gushing did not stop. The reason was that, a pipe being plunged into the oil from above the service tank, a back flow of the oil occurred through the siphon action. The spill was finally stopped by opening an air vent valve of the piping. Upon removing an insulating material and checking the leakage part, it was found that a pipe with a drain valve attached was broken, making a hole. The outward appearance had seemed normal when inspection was made from the drainage channel to the river. However, the leaked oil had already flown to the mouth of the river at low tide and drifted into the sea. The spill was estimated to be 9kl. The cause of the accident was due to the lack of reinforcement such as bosses and metal patches on the pipe installation at the time of welding. 8 figs.

  7. Spatial autocorrelation method using AR model; Kukan jiko sokanho eno AR model no tekiyo

    Yamamoto, H.; Obuchi, T.; Saito, T. [Iwate University, Iwate (Japan). Faculty of Engineering


    Examination was made about the applicability of the AR model to the spatial autocorrelation (SAC) method, which analyzes the surface wave phase velocity in a microtremor, for the estimation of the underground structure. In this examination, microtremor data recorded in Morioka City, Iwate Prefecture, was used. In the SAC method, a spatial autocorrelation function with the frequency as a variable is determined from microtremor data observed by circular arrays. Then, the Bessel function is adapted to the spatial autocorrelation coefficient with the distance between seismographs as a variable for the determination of the phase velocity. The result of the AR model application in this study and the results of the conventional BPF and FFT method were compared. It was then found that the phase velocities obtained by the BPF and FFT methods were more dispersed than the same obtained by the AR model. The dispersion in the BPF method is attributed to the bandwidth used in the band-pass filter and, in the FFT method, to the impact of the bandwidth on the smoothing of the cross spectrum. 2 refs., 7 figs.

  8. Self-repairing of material damage. Sonsho wo jiko shufuku yokushisuru zairyo

    Matsuoka, S. (National Research Inst. for Metals, Tsukuba (Japan))


    In order to control the damage like crack or void formed during the use of structural material by the material itself, it is required to self-detect the damage, to self-judge the state of damage, and to self-control or self-repair the damage finally. Based on the parameter of length, the repair and control is classified into the 1mm-scale functional fine wire and thin film utilization type, 1[mu]m-scale microcapsule type, and 1nm-scale trace element utilization type. For the damage repair and control of functional fine wire and thin film utilization type, the damage is repaired and controlled by pasting thin film or by embedding fine wire of functional material, such as shape memory alloy, Ti-Ni, and piezoelectric ceramics PZT (lead zirconate titanate), on the material surface or inside the material. For the damage repair and control of microcapsule type, is illustrated the control mechanism of high temperature fatigue crack propagation by Y2O3 particles dispersed in the Fe-20Cr alloy. Furthermore, the formation mechanism of self-repairing film by the trace element is also illustrated. 13 refs., 5 figs.

  9. Completion of Akita Petroleum Storing Base and commencement of stockpiling; Akita sekiyu bichiku kichi no zenmen kansei to oil in ni tsuite



    A report was made on the characteristics and the commencement of stockpiling of the Akita Petroleum Storing Base (Ojika City, Akita Prefecture; storing capacity 4,500,000kl) which was completed in June, 1995 with its overall operation started in July in the same year. This base is the only example that employed an underground tank system in the national storing bases in Japan. The following are described in the report. The crude oil tank, a reinforced concrete construction with 97m in diameter and 48m in underground depth, was built in a mudstone ground; as an underground tank system, it was required to have only one half of the tank diameter for the distance between tanks, and was a storing facility with a better area efficiency than an aboveground system; the oil stockpiling was commenced for 890,000kl in 1989, 2,010,000kl from 1992 through 1993 and 580,000kl in 1994, and a capability for a smooth release in emergency was confirmed; no abnormality was observed in the existing dispensing tank (aboveground type) at the time of the earthquake (seismic intensity: 5) in May, 1983; and so on. 7 figs., 2 tabs.

  10. Modified spatial autocorrelation method using autoregressive model for estimating underground velocity structure from microtremor array observation; Bido array tansa ni okeru kukan jiko sokanho no jiko kaiki model wo mochiita kairyo

    Yamamoto, H.; Saito, T. [Iwate University, Iwate (Japan). Faculty of Engineering; Obuchi, T. [Kawasaki Geological Engineering Co. Ltd., Tokyo (Japan)


    Spatial autocorrelation method (SAC) is an effective analysis for estimating underground S-wave velocity structure from microtremor phase velocity dispersion relation because it has larger detectable range of microtremor wavelength than frequency-wavenumber analysis. However, phase velocities estimated by conventional SAC methods such as band-pass filtered method or Fast Fourier Transform method were not precise if suitable band width was not selected for analysis. We proposed a new technique for SAC using autoregressive model which estimated spectra with high resolution because the best fitting model can be selected using AIC. We apply the new method to calculate phase velocities of microtremors which were observed at a ground of Morioka Technical High School with arrays. As a result, phase velocities calculated by the new method were continuous with frequency although those calculated by the conventional methods were scattered. This indicates that SAC functions calculated by the new method are estimated better than those by conventional SAC methods. 13 refs., 7 figs.

  11. Examination of poisonous gas in Matsumoto city, Nagano Pref.; Matsumotoshi ni okeru yudoku gas chudoku jiko eno taio

    Furuhata, A. [Nagano Research Inst. for Health and Pollution, Nagano (Japan)


    This report explains how the Sanitation and Pollution Laboratory of Nagano Prefecture came to isolate sarin and describes some examples of information gathering efforts which played a very important role in the sarin isolating process. The Matsumoto sarin incident took place late at night of June 27, 1994. The laboratory acting upon a request of the prefectural pollution control section completed its specimen collecting in the afternoon of June 28. In its efforts to search for the casualty-causing substance, the laboratory gathered information from the National Institute of Hygienic Sciences, Japan Poison Information Center, JICST, Matsumoto Health Center, and Professor Naito of the Tsukuba University. Next, the analysis/retrieval team started collecting data from the GC-FPD and GC-MS. The peak in the curve pointed to sarin, and this also made it clear that the substance was neither soman nor tabun. A question remained unanswered as to why sarin, a nerve gas which is a weapon of war, existed in a peaceful castle town of Matsumoto. The greatest difficulty in the sarin isolating process came from the lack of the standard substance to which sarin was to be referred to. Sarin was determined to be the responsible substance only after a general judgement based on the results of comparison with the retention indexes, analysis using the GC-MS (EI) and then GC-MS (CI), and experiments using Japanese cyprinodont. 8 refs., 1 tab.

  12. Problems of the security of facility viewed from accident information; Jiko joho kara mita setsubi hozen no kadai

    Nishikawa, K. [The High Pressure Gas Safety Inst. of Japan, Tokyo (Japan)


    In petroleum complexes and chemical complexes in which the control of operation of the plants is being automated, most of the accidents recently occurring are accidents occurring during, especially, works which are difficult to automate, such as non-steady work and maintenance work rather than accidents ascribed to erroneous operation. The number of aged facilities has increased, and the facility maintenance work tends to be subcontracted increasingly. The facility engineering will become a still more important problem in the future. The High Pressure Gas Safety Institute of Japan has issued a compendium on the safety of high pressure gas every year since 1987, and they issued a collection of examples of accidents in complexes in 1991. This paper introduces main examples of the accidents concerning the facility maintenance, extracted from the accident information recorded in the compendium and the collection of examples of accidents. Finally, lessons learned from the accident information are enumerated, and future problems are posed which include subcontraction of the facility maintenance work, the facility management cost and the facility safety. 6 refs., 1 fig., 1 tab.

  13. Preventive counterplan for chemical poisonings and the role of toxicology; Kagaku busshitsu chudoku jiko taisaku to dokubutsugaku

    Yoshida, T. [Showa Univ., Tokyo (Japan). School of Pharmaceutical Sciences


    Some cases of poisoning by chemical substances are taken up, and counterplans are discussed. This report centers about the neurotoxic gas sarin incidents dealing with them as examples of acute poisoning caused by chemical substances. The important difference in terms of chemical structure between a neurotoxic gas and organo-phosphoric pesticide is that in the former phosphorus is directly bonded with carbon or halogen while, in the latter, bondage is represented by P-O-C, P-S-C, and the like, so bonded as to form the phosphoric acid, thiophosphoric acid, or dithiophosphoric acid. The result of the difference in chemical structure is that the neurotoxic gas easily gains access to the target enzyme and remains stable after bonding therewith while the organo-phosphoric pesticide is easily hydrolyzed by enzymes other than the target enzyme. Poisoning by neurotoxic gas or organo-phosphoric pesticide is clinically treated by the administration of atropine and 2-pyridine aldoxime methiodide which is an antidote. It is mandatory to let people clearly know beforehand the methods of analysis of chemical substances and their toxicity and to establish beforehand how to first-aid the victims and what emergency treatment can be executed. 11 refs., 2 figs., 2 tabs.

  14. Research of self-positioning measurement systems for mobile robots. Ido robot no jiko ichi keisoku hoho no kenkyu

    Tanaka, Y. (Shinryo Corp., Tokyo (Japan)); Kajitani, M.; Kanamori, C.; Ito, H. (University of Electro-Communications, Tokyo (Japan))


    Self-positioning measurement systems on mobile robots used at construction sites were discussed. The present study has proposed a system to measure self-position of a robot using as reference the pillars installed at intervals of several meters to ten and several meters, of which absolute positions are known. The measurement system detects the edge of a pillar, measures inter-edge angle from the edge angle, and calculates a positional coordinate from the inter-edge angle. Distance measurement uses a reflected light distance meter on laser light. Discussions on errors were carried out, providing the following findings: in order to limit a positional error to 5 mm or less, the angular error must be maintained within 2 minutes and 50 seconds, for which the laser light diameter should be 8.2 mm or less for a distance of 10 meters for example; a lens focus shall preferably be focused at the farthest distance; and positional error of a pillar in construction work of 5 mm corresponds to an angular error of 1 minute and 15 seconds. The system consists of a laser reflection distance measuring instrument, an angle detector, and a data processor. Its measurable range is up to 15 meters. The positional coordinate accuracy is [plus minus] 0.7 mm, and other measurement errors are within [plus minus] 5 mm. This system can be used on robots. 6 refs., 16 figs., 3 tabs.

  15. Effects of mechanical stimulating treatment on self-organization phenomena of materials; Kikaiteki reiki shori. Zairyo no jiko soshikia gensho ni oyobosu sono koka

    Hida, M. [Okayama University, Okayama (Japan). Faculty of Mechanical Engineering


    The atoms and atom clusters around dislocation cores in crystals or surface layer deformed by mechanical energy are locally excited so as to give rise some chemical reactions and to self-organize their products into a kind of Spatial-Temporal Pattern Formation as a dissipative structure. A famous coupling phenomenon between mechanical and chemical process in solid materials must have been mechanical alloing. This report explains that various mechano-chemical treatments are powerfull method for entraining the solid system into non-equilibrium states and interesting phenomena stimulated by the mechanical self-catalysis reaction causing self-organization. (author)

  16. Recent progress and pending problems in marketing and technology for base isolation rubber bearings; Menshin yo sekiso gomu no ichiba , gijutsu doko to ken`an jiko

    Fukahori, Y. [Bridgestone Corp, Kanagawa (Japan)


    Market and technology trends of seismic rubber bearings (SRB) after Hannshin-Awaji big earthquake are explained, and problems to overcome for spreading seismic isolation are considered with both aspects of technology and regulation. Since the big earthquake, the market of SRB for buildings has been rapidly activated, sale in 1997 being predicated to amount twice as much that in 1996. For ordinary seismic buildings, their seismic designing is conducted under assumption that intrinsic frequency of earthquake wave should be 2 seconds at longest. It is preferable to assume longer frequency for larger seismic effect. However, the longer the frequency is assumed, the larger the deformation of SRB should occur on earthquake, resulting in being liable to buckle or rupture. Thus, SRB is tend to be larger and replacement of SRB/damper integral type SRB to separate type wherein they are set separately for more damping, has been proceeding. Whereas bearing load of SRB to vertical direction has be presumed to be 50{approx}80 kg/cm {sup 2}, use under much higher face pressure is requested lately. However, the increase in load induces increase in compression creep, promoting material deterioration. This problem is discussed in detail with material strength data. 6 refs., 17 figs.

  17. Can spatial autocorrelation method be applied to arbitrary array shape; Kukan jiko sokanho no nin`i array eno tekiyo kanosei

    Yamamoto, H.; Iwamoto, K.; Saito, T.; Tachibana, M. [Iwate University, Iwate (Japan). Faculty of Engineering


    Methods to learn underground structures by utilizing the dispersion phenomenon of surface waves contained in microtremors include the frequency-wave number analysis method (the F-K method) and the spatial autocorrelation method (the SAC method). Despite the fact that the SAC method is capable of exploring structures at greater depths, the method is not utilized because of its stringent restriction in arrangement of seismometers during observation that they must be arranged evenly on the same circumference. In order to eliminate this restriction in the SAC method, a research group in the Hokuriku University has proposed an expanded spatial autocorrelation (ESAC) method. Using the concept of the ESAC method as its base, a method was realized to improve phase velocity estimation by making a simulation on an array shifted to the radius direction. As a result of the discussion, it was found that the proposed improvement method can be applied to places where waves come from a number of directions, such as urban areas. If the improvement method can be applied, the spatial autocorrelation function needs not be even in the circumferential direction. In other words, the SAC method can be applied to arbitrary arrays. 1 ref., 7 figs.

  18. Discussion on sensor location in circular array for spatial autocorrelation method; Kukan jiko sokanho no enkei array ni okeru jishinkei haichi no kento

    Yamamoto, H.; Iwamoto, K.; Saito, T.; Yoshida, A. [Iwate University, Iwate (Japan). Faculty of Engineering


    Methods to derive underground structures by utilizing the dispersion phenomenon of surface waves contained in microtremors include the frequency-wave number analysis method (the F-K method) and the spatial autocorrelation method (SAC method). The SAC method is said capable of estimating the structures to deeper depths than with the F-K method if the same seismometer is used. However, the F-K method is used more frequently. This is because the SAC method imposes a strict restriction that seismometers must be arranged evenly on the same circumference, while the F-K method allows seismometers to be arranged arbitrarily during an observation. Therefore, the present study has discussed whether the SAC method can be applied to observations with the seismometers arranged in the same way as in the F-K method, by using microtremor data acquired from actual observations. It was made clear that a seismometer arrangement for the SAC method may be sufficed with at least three meters arranged on the same circumference. These meters may not have to be arranged evenly, but because the acquired phase velocities may vary according to wave arriving directions and seismometer arrangement, it is desirable to perform observations with seismometers arranged as evenly as possible. 13 figs.

  19. Explosion in a rotary dryer at a chemical factory. Eikoku kagaku koho no kaiten kansoki no bakuhatsu jiko (shiryo kenkazai no netsubunkai boso hanno)

    Shioji, Y. (Nippon Oil Co. Ltd., Tokyo (Japan))


    This paper reports a dryer explosion and fire accident in the Dow Chemical {prime}s King {prime}s Lynn factory in Great Britain. Nine other accidents of dryers on the similar type are also reported to indicate the importance of advance evaluation on substances for their hazard. The subject accident occurred while a group leader was reporting a gushing sound and white smoke from the door of the dryer room at a little after 17:00 on June 27, 1976, an explosion bursted at 17:10 causing an immediate death of an operator due to a blast from the explosion. THE damage of the manufacturing equipment is estimated to have amounted to about 1.25 million pounds. The exolosion accident has occurred when the Zoalene (product name), a chicken feed additeve, has been left in a dryer in nearly a sealed condition for 27 hours after having been dried, its temperature was maintained at 120-130 {degree}C as a result of heat insulating effect of the insulators on the dryer. This caused a pyrolysis of the product, of which heat accelerated the pyrolysisand led to an explosion. One of the basic causes was that no safety evaluation technique has been established to predict danger of the drying operation. 2 refs., 5 figs.

  20. Fixed position holding control for self-propulsion barges under disturbance condition; Gairanka ni okeru jiko baji no teiten hoji seigyo ni tsuite

    Kijima, K.; Murata, W.; Furukawa, Y. [Kyushu University, Fukuoka (Japan). Faculty of Engineering


    In direct hoisting work in suspension bridge construction, since a cable crane directly hoists a bridge beam block put on a barge on the sea, precise fixed position holding function is required for a barge. The control system was then designed on the basis of an ILQ control theory, and the effect of change in time constant as design parameter on fixed position holding performance was studied. In addition, the critical disturbance for fixed position holding control was studied through numerical simulation under various disturbance conditions using the above designed control system. As a result, in the design of control systems on the basis of an ILQ control theory, the precise control system could be designed by diminishing, in particular, the time constant for state variable around a z axis among time constants according to the extent of disturbance. The control performance was largely affected by response delay period from sensing of disturbance to beginning of control. 3 refs., 7 figs., 2 tabs.

  1. Quantum analysis in the transition process to excited state of an oxygen molecule induced by electron collisions; Denshi shototsu ni tomonau sanso bunshi ni okeru reiki jotai sen`i no ryoshironteki kaiseki

    Ishimaru, K. [Gifu National College of Technology, Gifu (Japan); Okazaki, K. [Tokyo Inst. of Technology, Tokyo (Japan)


    For understanding of fundamental chemical reactions under a highly non equilibrium condition which is quite often used in plasma processing, the relevant atomic and molecular processes must be clarified. In this study, an analysis of the transition process to the excited state of an oxygen molecule induced by electron collisions in the oxygen plasma has been carried out. First, the electron density distribution in an oxygen molecule has been calculated using the extended Huckel molecular orbital method. Then, the electron potential energy distribution in the transition process to the excited state has been estimated. The electron behavior has been calculated using the estimated unidimensional electron potential energy distribution and unsteady quantum mechanics. As a result, the transition process to the excited state of an oxygen molecule induced by electron collisions and its conditions have been clarified qualitatively. 9 refs., 9 figs.

  2. Determination of electron impact ionization and excitation coefficients in He-Xe gas mixtures. He-Xe kongo gas ni okeru denshi shototsu denri keisu oyobi reiki keisu no sokutei to kaiseki

    Takahashi, K.; Tachibana, K. (Kyoto Inst. of Technology, Kyoto (Japan))


    The rare gas discharge gives a stable discharge and light emission characteristics at low temperature in comparison with the discharge of the vapor of such a metal as Hg. The present barrier for the commercialization of the color PDP lies in the lower level of its emission intensity and efficiency in comparison with that of CRT. In this report, an electron impact ionization coefficient in a gas mixture and an electron impact excitation coefficient for a XeIs {sub 4} level were analyzed using a Boltzmann equation by means of a steady state Townsend method using a drift tube. By comparing both, the elementary process in the gas mixture is investiagted to discuss the respective contributions for the effective ionization coefficient and the excitation coefficient. As a result, it was found that the ionization process in the He-Xe gas mixture could be described by the processes of direct ionization of Xe and He, and an indirect ionization (Penning effect) by an active helium. 37 refs., 12 figs.

  3. Heat and fluid flow properties of circular impinging jet with a low nozzle to plate spacing. Improvement by nothched nozzle; Nozzle heibankan kyori ga chiisai baai no enkei shototsu funryu no ryudo dennetsu tokusei. Kirikaki nozzle ni yoru kaizen kojo

    Shakouchih, T. [Mie University, Mie (Japan). Faculty of Engineering; Matsumoto, A.; Watanabe, A.


    It is well known that as decreasing the nozzle to plate spacing considerably the heat transfer coefficient of circular impinging jet, which impinges to the plate normally, increases remarkably. At that time, the flow resistance of nozzle-plate system also increases rapidly. In this study, in order to reduce the flow resistance and to enhance the heat transfer coefficient of the circular impinging jet with a considerably low nozzle to plate spacing, a special nozzle with notches is proposed, and considerable improvement of the flow and heat transfer properties are shown. The mechanism of enhancement of the heat transfer properties is also discussed. (author)

  4. Three-dimensional computer simulation at vehicle collision using dynamic model. Application to various collision types; Rikigaku model ni yoru jidosha shototsuji no sanjigen kyodo simulation. Shushu no shototsu keitai eno tekiyo

    Abe, M.; Morisawa, M. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Keio University, Tokyo (Japan); Kobayashi, K. [Molex-Japan Co. Ltd., Tokyo (Japan)


    The past study of safety at vehicle collision pays attention to phenomena within the short time from starting collision, and the behavior of rollover is studied separating from that at collision. Most simulations of traffic accident are two-dimensional simulations. Therefore, it is indispensable for vehicle design to the analyze three-dimensional and continuous behavior from crash till stopping. Accordingly, in this study, the three-dimensional behavior of two vehicles at collision was simulated by computer using dynamic models. Then, by comparison of the calculated results with real vehicles` collision test data, it was confirmed that dynamic model of this study was reliable. 10 refs., 6 figs., 3 tabs.

  5. Study on a small diesel engine with direct injection impinging distribution spray combustion system. Optimum of injection system and combustion chamber; Shototsu kakusan hoshiki kogata diesel kikan ni kansuru kenkyu. Funshakei to nenshoshitsu no saitekika

    Fujita, K.; Kato, S.; Saito, T. [Kanazawa Institute of Technology, Ishikawa (Japan); Tanabe, H. [Gunma University, Gunma (Japan)


    This study is concerned with a small bore (93mm) diesel engine using impinged fuel spray, named OSKA system. The higher rate of injection show lower smoke emission with higher NOx Emission. The exhaust emission and performance were investigated under different compression ratio with higher rate of injection. The experimental results show that this OSKA system is capable for reducing the smoke emission without the deterioration of NOx emission and fuel consumption compared with the conventional DI diesel engine. 5 refs., 8 figs., 3 tabs.

  6. Impingement of a radial jet with an annular jet. 3rd Report. Curved properties of main jet with pressure field; Hoshajo funryu to kanjo funryu no shototsu ni kansuru kenkyu. 3. Atsuryokuba ni yoru shufunryu no wankyoku tokusei

    Tanaka, T.; Kozato, Y.; Tanaka, E. [Gifu University, Gifu (Japan). Faculty of Engineering; Kariya, M. [Meidensha Corp., Tokyo (Japan)


    Annular jets (control flows) flowing out from a columnar nozzle and a concentrically circular annular nozzle were impinged perpendicularly to a main jet flowing radially from the columnar nozzle. Then, an investigation was given on pressure in a recirculation flow region, bending of the main jet, and reattachment characteristics of the main jet onto a side wall face when the deflection of the main jet and its reattachment phenomenon onto the side wall face are controlled. The experiment was performed under the conditions of a nozzle width of 6 mm, an inter-nozzle distance of 4, a control flow rate (a ratio of a flow-out rate of the control flow to that of the main jet) from 0 to 0.6, with the step height varied. Investigations were made on change of static pressure distribution in jets in the downstream direction, change of static pressure on the side wall face in the downstream direction, and the relationship between the reattachment position on the side wall and the average static pressure in the recirculation flow region. The relationship of the reattachment position of the main jet on the side wall with the average side wall static pressure and the average static pressure in the recirculation flow region is expressed by one curve. The reattachment position gets closer to the nozzle outlet as the pressure decreases in the recirculation flow region. 9 refs., 14 figs., 1 tab.

  7. Development of stratified-charge engine by impingement of fuel jet. ; Test results with gasoline fuel. Chokufunshiki shototsu kakusan sojo kyuki kikan no kaihatsu. ; Gasoline nenryo ni yoru jikken kekka

    Kato, S.; Onishi, S. (Japan Clean Engine Lab. Co. Ltd., Ishikawa (Japan))


    Development was made of direct fuel injection stratified-charge method (OSKA nethod), to make the mixture formation in the direct fuel injection engine by having fuel jet positively impinge on the impingement part, installed in the combustion chamber. In the present report, the following conclusion was obtained through experiment on gasoline fuel by a single cylinder engine with a spark ignition method, combined with the OSKA method: High compressive ratio was made adoptable by applying an OSKA method, using a single hole nozzle with low opening pressure. Due to feed air swirl, made unnecessary for the mixture formation, adoption of early injection under the high load, etc., the highest brake mean effective pressure attained to 1.04MPa, which is almost equivalent to that of carburetor type automobile gasoline engine, while the highest brake thermal efficiency did to 37.7%, which is so to that of direct fuel injection diesel engine, equal in volume. Also under the low load, obtained was a high thermal efficiency, nearing that of diesel engine. 8 refs., 9 figs., 2 tabs.

  8. Effect of the velocity ratio on the turbulent structure of the plane wall jet under the self-preserving state. 1st Report. ; Conditions for self-preservation and mean flow field. Jiko hozon jokenka no heimen hekimen funryu no ranryu kozo ni oyobosu sokudohi no eikyo. 1. ; Jiko hozon no joken to heikin sokudoba

    Osaka, H.; Mchizuki, S. (Yamaguchi University, Yamaguchi (Japan)); Tominaga, T. (Yamaguchi University, Yamaguchi (Japan))


    Relation was studied between the turbulent structure and velocity ratio of plane wall jet of the self-preserving liquid, constant in pressure gradient (velocity ratio). The experimental unit for the study is 100mm in height (S{sub 1}) of jet outlet in the flowing field, 384mm in height of external flow outlet, 400mm in width of both those outlets and approximately 2400mm in length of aluminum made plane for the measurement. To measure the mean velocity and frictional stress against wall surface, used were Pitot and Preston tubes. As a velocity ratio, setting was made at the three values, i.e., 2.0, 2.9 and 4.0. The mean flow gives self-preserving characteristics in the range of 57

  9. Accuracy of LLP system and lightning frequency map evaluated from transmission line faults; Rakurai ichi hyotei system no seido to rakurai hindo map no sodensen torippu jiko ni motozuku hyoka

    Shinjo, K.; Wakai, T.; Sakai, T. [Hokuriku Electric Power Co., Inc., Toyama (Japan)] Ishii, M. [Tokyo Univ. (Japan)


    Accuracy of an LLP system and a lightning frequency map is evaluated by using transmission line faults in Hokuriku area from November in 1993 to October in 1996. The accuracy and efficiency of the system were calculated by statistical methods. From the above results, the lightning frequency map with 10 minutes meshes was proved capable of replacing the Isokeraunic Level Map with 15 minutes meshes used now for lightning protection design. However, the correlation between the number of detected lightning flashes and transmission line faults in each mesh was found to be week. This result suggests that more detailed analysis taking account of the length of transmission lines in each mesh is necessary. The correlation is stronger in winter than in summer, despite the fact that there is difference in the lightning current distribution in each mesh in winter. This characteristic can be explained if upward flashes from transmission lines are dominant among lightning faults in winter. 19 refs., 11 figs., 6 tabs.

  10. Neural network with a self-selection ability of input variables for a nonlinear system identification; Nyuryoku hensu no jiko sentaku noryoku wo sonaeta hisenkei system dotei yo neural network

    Kondo, T. [School of Medical Sciences, The University of Tokushima., Tokushima (Japan)


    When neural network is applied to identification problem with complex structure, structure of the network becomes larger in its scale and more complex as its input variables increase, because of necessity on effect of high order in the input variable within the network. In this study, a neural network with self-selection ability of the input variables is proposed. This network can remove the neuron related to the input variables from inner portion of the network according to the prediction error estimation standard and construct a neural network only by means of the neuron related to useful input variables, even when it contains unnecessary variables for its input variable. In this paper, by comparing with identification results obtained by conventional neural network or improved GMDH method, its effectiveness could be elucidated. And, it applied to short-term forecasting problem of air pollution concentration, to compare its estimation accuracy with those of other prediction models. 18 refs., 10 figs., 3 tabs.

  11. Self-rehealing characteristics of a sodium current limiter and its over current coordination for low voltage distribution systems; Natoriumu (Na) genryu soshi no jiko fukkyu tokusei to teiatsu haiden kairo oyo ni okeru kadenryu kyocho

    Wada, Y.; Hamano, S.; Mori, T. [Mitsubishi Electric Corp., Tokyo (Japan)


    As one of the short circuits protection techniques in a power circuit, there is a technique called the current-limiting breaking. When a short circuit current commences to flow after a short circuit occurs, this technique limits and breaks this current under a certain value by some measures before this current reaches to the crest value. There is a current-limiting fuse in the best known one as a functional element doing the current-limiting breaking. However in case of a current-limiting fuse, when an element is fused off, because a current can not be flowed, it has to be replaced. As a new element to eliminate this defect and moreover with a current-limiting function, a self-rehealing type current-limiting element possessing the alkaline metal, Na as an element has been developed. In this report, as for this element called Na current-limiting element, together with elucidating a rehealing process after the current-limiting action experimentally in detail, an overcurrent coordination is investigated when this element is applied to a main circuit of the control center, which is one of the low voltage distribution systems. 5 refs., 8 figs., 1 tab.

  12. On-site processing systems for determination of the phase velocity of Rayleigh waves in microtremors using the spatial autocorrelation method; Kukan jiko sokanho wo mochiita bidochu no Rayleigh ha iso sokudo no genba kettei system

    Matsuoka, T.; Umezawa, N. [Saitama Institute of Environmental Pollution, Saitama (Japan)


    To render the spatial autocorrelation (SAC) method easier to use, a system has been constructed that can be used with ease on the site for the calculation of phase velocities. This system can perform two observation methods of the same frequency characteristics, that is, the simultaneous multi-point observation and one-point independent observation. The pickup is a velocity type seismograph of a natural period of 1 second that has been so electrically adjusted as to work on an apparent natural period of 7 seconds. Among the frequency characteristics, those related to phase are regarded as important because the SAC method is based on the measurement of coherence between two points. The analysis software runs on a waveform processing software DADiSP/WIN designed for personal computers. To know the operability of this system on the site and to accumulate records using the SAC method, observations were made at the depth of 100-500m at 6 locations in Saitama Prefecture where the underground structure was known thanks to prior PS logging. As the result, a dispersion curve was obtained by use of an array of appropriate dimensions at every location agreeing with the underground structure. 9 refs., 10 figs.

  13. Quantitative analysis of schlieren photographs for internal combustion engine diagnostics. 2nd Report. ; Smoothing of background distortion and analytical results of transient wall-impinging jet. Nainen kikan ni okeru schlieren shashin no teiryoka gazo shoriho ni kansuru kenkyu. 2. ; Background no yugami jokyo, narabini hiteijo hekimen shototsu funryu no kaiseki kekka

    Ouchi, H.; Chikahisa, T.; Murayama, T. (Hokkaido Univ., Sapporo (Japan). Faculty of Engineering)


    It was previously reported, for the research on the internal combustion engine, that the quantitative analysis of Schlieren photographs, one of simple visualization technologies, is effective on the heightening in accuracy of the analysis by Schlieren photographs and however, insufficient in countermeasures against the background distortion, causing errors. Then, by removing background distortion and analyzing Schlieren photographs, taken of transient wall-impinging jet, evaluation was made of the present quantitative analysis. As a result, a method could be shown to effectively correct the background distortion. Further, upon analyzing transient wall-impinging jet by that method, result could be obtained to be sufficiently accurate to grasp its structural characteristics. The resent quantitative analysis is advantageous in capability of, among others, monentarily quantify the two-dimensional phenomenon by a simple unit, and support the quantitative information for the Schlieren measurerment, widely used in the research on the internal combustion engine. 8 refs., 8 figs.

  14. Performance of direct injection methanol engine using the fuel jet impingement and diffusion. ; Comparison between the spark plug and glow plug ignitions. Nenryo funryu no shototsu kakusan wo riyoshita chokufun methanol kikan no seino. ; Spark plug oyobi glow plug chakka hoshiki no hikaku

    Kato, S.; Onishi, S.


    The purpose of this paper is to compare the performance of direct fuel injection methanol engines with the spark plug and glow plug ignition systems. These methanol engines utilize the formation of fuel-air mixture by the fuel jet impingement and diffusion. Engine performance and cylinder pressure for the both ignition systems were analyzed. Piezoelectric pressure indicator was used for the cylinder pressure measurements, and combustion analyzer was used for their analyses. In order to estimate engine performance, effects of load and engine speed were analyzed. Consequently, almost the same brake thermal efficiencies (maximum value of 42%) were obtained for both ignition systems. For the glow plug ignition system, the combustion noise and NOx emission were lower than the spark plug engine. The NOx emission did not excess 500ppm with the glow plug ignition system. In the impingement and diffusion method, both the piston attached type impingement part and cylinder head fixed type one were applicable. 4 refs., 9 figs., 2 tabs.

  15. Study on the two-dimensional jet impinging on a circular cylinder. 1st report. ; Measurements of flow-field and heat transfer around a circular cylinder mounted near two flat plates. Enchu eno nijigen shototsu funryu ni kansuru kenkyu. 1. ; Enchu ni kinsetsushite secchishita heiban no nagareba oyobi enchu netsudentatsu eno eikyo

    Haneda, Y.; Kurasawa, H. (Nagano National College of Technology, Nagano (Japan)); Tsuchiya, Y. (Shinshu Univ., Nagano (Japan). Faculty of Engineering); Suzuki, K. (Kyoto Univ., Kyoto (Japan). Faculty of Engineering)


    The flow field and heat transfer around a circular cylinder is investigated experimentally when two dimensional jet is impinged on a circular cylinder mounted near two flat plates which are set at a fixed inclination against the axis of jet. Flow field varies markedly depending on whether the minimum channel width is the minimum space B between the flat plates or the space C between the cylinder and the plates. The local Nusselt number of the cylinder strongly depends on the value of space C between the cylinder and the plates. The minimum and maximum locations correspond to the locations of separation and reattachment, respectively, of the flow around the cylinder. When the ratio between the nozzle-to-cylinder distance L and the short side h of the nozzle is 3 (L/h=3), the mean Nusselt number around the cylinder becomes the maximum when C/D is 0.1 where D is the diameter of the cylinder, and increases by about 9 to 12% as compared with the case where no plate is provided. For L/h=7 and L/h=10, the mean Nusselt number does not increase distinctly as compared with the case where no flat plate is provided. 16 refs., 15 figs.

  16. Quantitative evaluation of difference in impact of grounding accident on zero-phase voltage and zero-phase current in 6kV distribution system. Results of EMTP simulation; 6kV haiden keito deno chiraku jiko yoso no reiso den`atsu, reiso denryuha eno eikyo ni kansuru teiryoteki hyoka. EMTP (Electro Magnetic Transients Program) simulation kekka

    Nagai, K. [Kansai Electric Power Co. Inc., Osaka (Japan)


    EMTP (electromagnetic transients program) analysis using accident spot models is conducted to disclose the different effect exerted on the zero-phase voltage and zero-phase current by different grounding accidents. An accident spot producing a near-delta waveform is represented by an equivalent circuit model No. 1 in which a switch simulating a discharge gap and the accident spot resistance are connected in series. In the case of an accident presenting a near-needle waveform, since it is supposed that the discharge is caused to be intermittent because the gap discharge start voltage is high and the accident spot resistance is low, it is presented by an equivalent circuit similar in configuration to model No. 1 with the constants altered. A leak-suggesting waveform with a current flowing even in the neighborhood of the zero cross point is represented by model No. 1 with a leak resistor added in parallel thereto, which circuit is shown as model No. 2. In the accidents represented by model No. 1, zero-phase current waveforms are grouped into three types, and the relations between the switch on-off circuit/grounding resistance and waveform configuration are disclosed. As for the accidents represented by model No. 2, it is found that the leak resistance values fall somewhere in the 200-2000 ohm range. 2 refs., 6 figs., 2 tabs.

  17. Applicability of the spatial autocorrection method for estimation of basement structure in Kanto plain. Array measurements of microtremors close to the Iwatsuki and Shimosa deep borehole observatory; Kanto heiya no kiban kozo suitei no tame no kukan jiko sokanho no tekiyosei. Iwatsuki Shimosa jiban katsudo kansokusei ni okeru array bido kansoku

    Matsuoka, T.; Umezawa, N.; Shiraishi, H. [Saitama Institute of Environmental Pollution, Saitama (Japan)


    To investigate applicability of the spatial autocorrection method which is a microtremors exploration method for the estimation of basement structure, array measurements of microtremors were performed using the Iwatsuki and Shimosa deep borehole observatory where detailed structures were clarified as well as the Fuchu and Koto deep borehole observatory. In this study, estimated velocity structures of S-wave were compared with the geological sequence and results of acoustic velocity logging. The phase velocity was estimated by the spatial autocorrection method using FFT. The phase velocity with a smooth normal dispersion was observed in the periodic range from 0.5 to 5 sec in Iwatsuki, and from 0.5 to 4 sec in Shimosa by the combination of four-point circular arrays with radii of 100, 300, and 600 m. The underground structures estimated from the phase velocities coincided well with the geological sequence, and results of acoustic velocity logging and velocity logging for each borehole. For the Iwatsuki borehole, the basement velocity was also estimated properly in the periodic range of observation. While, for the Shimosa borehole, measurements with the period around 6 sec were required to estimate the basement velocity more accurately. 13 refs., 11 figs., 1 tab.

  18. Survey/research on application of expert system to electric power technology. Part 1. ; Protoypical preparation of accident section discrimination system by personal computer edition. Expert system no denryoku gijutsu eno tekiyo ni kansuru chosater dot kenkyu (1). ; Keito jiko kukan hantei system (pasokon ban) no shisaku

    Sugihara, H. (The Chugoku Electric Power Co. Inc., Hiroshima (Japan))


    As the first step in the prototypical preparation of system accident recovery support system'', in order to support the accident phenomenon comprehension and recovery operation, to be done by the operators at the time of accident occurrence in the electric power system, accident section discrimination system by personal computer edition'' was prototypically prepared for the purpose of discussing the knowledge expression and inference method. That system is, at the time of system accident occurrence, to discriminate the accident section from the information of operated protective relay and tripped circuit breaker, and was structured of objective system model and about 100 production rules (knowledge under a form of if {yields} then''). As the rule was made not to depend upon a proper system, change in system structure and protection system can be corresponded to by change in objective system model only. Correct conclusion was obtained in 1 to 10 minutes, as a result of demonstration, made in about 50 cases of supposed accident, using a control system (12 buses, 2 power source buses, 12 power transmission circuits and 26 circuit breakers), based on the system in Takehara control station. 9 refs., 25 figs., 2 tabs.

  19. Exploration of underground basement structures in Kanto plain using the spatial autocorrelation method. 1. S-wave velocity structure along the line from Hatoyama, Saitama to Noda, Chiba; Kukan jiko sokanho ni yoru Kanto heiya no kiban kozo tansa. 1. Saitamaken Hatoyama machi - Chibaken Nodashi kan no S ha sokudo kozo

    Matsuoka, T.; Umezawa, N.; Shiraishi, H. [Saitama Institute of Environmental Pollution, Saitama (Japan)


    The Saitama prefectural government has been conducting basement structure exploration using the spatial autocorrelation method by dividing the entire plain area into meshes, for the purpose of improving the accuracy of estimating large-scale seismic damages. This paper reports the result of explorations on meshes in the east-west direction in the central part of Saitama Prefecture. The present exploration was intended on ten meshes in the east-west direction along the north latitude 36-degree line. The number of exploration points is 13 comprising three points on the hilly area bordering on the eastern edge of the Kanto mountainous area and ten points on the plain area. The arrangement constitutes a traverse line with a total distance of about 33 km from the west edge (Hatoyama-machi in Saitama Prefecture) to the east edge (Noda City in Chiba Prefecture). The phase velocities were estimated from the result of the array microtremor observations using the spatial autocorrelation method applied with the FET. The phase velocities were used to estimate underground structures by using an inverse analysis. As a result, detailed two-dimensional S-wave velocity structures were revealed on the traverse line. The velocity cross section expresses change in the basement structures with sufficient resolution, and at the same time the information is judged highly harmonious with existing deep boring data and the result of artificial earthquake exploration. 15 refs., 6 figs.

  20. Effect of the velocity ratio on the turbulent structure of the plane wall jet under the self-preserving state. 2nd Report. Turbulent field; Jiko hozon jokenka no heimen hekimen funryu no ranryu kozo ni oyobosu sokudohi no eikyo. 2. Ranryuba

    Osaka, H.; Mochizuki, S. [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering; Sugihara, M. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)


    In this study the plane wall jet under the self-preserving pressure gradient was measured to investigate the effect of the ratio of the maximum velocity Um to the external stream velocity Ue on the turbulent quantities. Velocity ratio Um/Ue was set at three values within the range of 2.0 to 4.0. Under such conditions, three components of turbulent intensity and Reynolds shear stress were measured by using two linearized hot wire anemometers. The turbulent flow is closely self-preserving in the range of 57

  1. FY 1995 basic research to develop instruments for diagnosis of atherosclerosis on the basis of autofluorescence analysis of blood and vascular walls; 1995 nendo ketsueki oyobi kekkanheki no jiko keiko bunseki ni yoru domyaku koka shindan kiki kaiahtsu no tame no kisoteki kenkyu



    To obtain the basic data to develop instruments for diagnosis of atherosclerosis and to elucidate the mechanisms of atherogenesis by focusing on the autofluorescence of blood and vascular walls of atherosclerotic animal models and human patients. We have performed experiments to examine the relationships between autofluorescence of blood and vascular walls of guinea pig atherosclerotic model and human patients and obtained the following results. 1. The autofluorescence from human atherosclerotic aorta included the components with longer wave length than normal aorta, suggesting that diagnosis of atherosclerotic aortic walls will be possible using spectroscopic analysis through glass fiber catheter into vascular system. Further studies should be needed to the quantitative diagnosis. 2. The autofluorescence from blood plasma of human atherosclerotic patients has showed that the peak wave length was shorter than that of normal plasma. This phenomenon was mainly caused by the oxidization of plasma, especially lipoproteins, LDL and HDL. 3. Atherosclerotic model of the guinea pigs was quite similar to human atherosclerosis at the points of cholesterol levels and localization of lipid deposit to arterial walls, and showed to be useful for the studies of atherosclerosis. (NEDO)

  2. Further reflections on the suicide of Kawabata Yasunari.

    Iga, M


    The suicide of Kawabata Yasunari has been studied in terms of loneliness, aestheticism, postwar Japan's mass democracy, and ill health and old age. This paper places focus on the Oedipus complex in relation to Kawabata's concepts of beauty, life, and death. This analysis was supported by the psychosocial data which were provided by Jiko no Tenmatsu (An Account of the Incident) by Usui Yoshimi. The book is based on the story told by a maid of Kawabata, who is believed to have played an important role in his suicide. Although it is a novel, Usui claims that he followed events as told by the reporter as closely as possible.

  3. Dichotomies of collectivism and individualism in bioethics: Selective abortion debates and issues of self-determination in Japan and 'the West'.

    Kato, Masae; Sleeboom-Faulkner, Margaret


    This article examines the dichotomies of collectivism and individualism in the debates on the selective abortion of disabled fetuses, which have occurred over the last four decades in Japan. Disagreements in debates on abortion in Japan have often revolved around the concept of self-determination (jiko-kettei). These debates usually focus on whether this 'foreign' concept is appropriate in a Japanese context, as the dominant Japanese discourse stereotypes the Japanese as making decisions in a harmonious manner. Both in public debates and in academic writing on abortion, the idea that the West is devoid of harmonious collectivism is often presented in an uncritical manner. In this article, we argue that the notion of 'self-determination' is borrowed from 'reverse Orientalist' and Occidentalist discourses that portray Westerners as individualistic or ego-centric and the Japanese as collectivist. The concept of 'self-determination' was remolded and projected onto Japanese public and academic debates on abortion. The relevance of this concept lies in the ways in which dichotomous views of 'Japan as harmonious' versus 'the West as individualistic' influence guidelines concerning prenatal testing and its daily practice. By critically analyzing the narratives of policy-makers and academic studies on self-determination and prenatal testing, this study traces these polarizing views back to the processes of national identity formation. These processes underlie political debates and academic work associated with the search for 'Japanese-ness'. This article further demonstrates that policy-makers' criticism of self-determination in prenatal testing derives from gender bias, which is also related to issues of Japanese identity. This article is based on both archival and field research materials collected between 1997 and 2008. We also refer to interviews with medical doctors, policy-makers, journalists, counselors, nurses, participants in various social movements and