Sample records for choogata futaishiki kaiyo

  1. Experimental study on the response of very large floating structures (VLFS) in wave; Choogata futaishiki kaiyo kozobutsu no harochu oto ni kansuru jikkenteki kenkyu

    Ota, M.; Ikegami, H.; Yamaguchi, Y. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)


    The elastic response of VLFS of 1200m long in wave was studied experimentally using a water tank and integral elastic model of 1/80 scale. As offshore airport, a ultra- thin box type floating structure of 5km long, 1km wide and several meter thick is used, and the effect of elasticity is not negligible for such a structure. The experiment used a water tank of 160m long, 30m wide and 3.1m deep. Supposing a water depth of 20m for real VLFSs, the experiment was carried out mainly in a local shallow water area prepared with a temporary bottom together with that in a deep water area. A simple mooring equipment with a linear spring equivalent to real VLFSs was used. The integral floating model was prepared by not mechanical but welded junction to obtain uniform elasticity. The response in wave showed a complicated 3-D behavior, offering useful data for verification of a behavior estimation method. The response was nearly equal between shallow and deep water areas at the same wave length, and the response amplitude in regular waves was equivalent to the significant amplitude in long and short crested irregular waves. 7 refs., 8 figs., 3 tabs.

  2. Hydroelastic responses of pontoon type very large floating offshore structures. 2nd Report. Effect of the water depth and the drift forces; Pontoon gata choogata futaishiki kaiyo kozobutsu no harochu chosei oto ni kansuru kenkyu. 2. Senkai eikyo to hyoryuryoku

    Maeda, H.; Miyajima, S. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Masuda, K.; Ikoma, T. [Nihon University, Tokyo (Japan). College of Science and Technology


    Steady-state drift force in regular waves is theoretically analyzed. It is also studied under combined external force experimentally using a two-dimensional water tank. The fluid forces are analyzed by the pressure distribution method based on the potential theory, in which the effects of water depth are taken into account to discuss the effects of elastic deformation of the floating structure on the drift characteristics of steady-state waves. The tests were carried out using a wave-making circulating water tank equipped with a wind duct to create wind, waves and tidal flow. Drift force under a combined external force by wind, wave and/or tidal flow cannot be accurately predicted by arithmetically adding these components. For predicting drift force by tidal flow, it is necessary to take into account drag force in current at the floating structure bottom as well as that in wind at the front face. Drift force by tidal flow is affected by shallowness of water, which should be taken into account for drag forces. The floating structure will be deformed along the wave face as its stiffness decreases, basically decreasing steady-state drift force. 9 refs., 14 figs.

  3. Assessment of a Mega-Float on water quality and ecosystem in Tokyo bay; Choogata futaishiki kaiyo kozobutsu ga Tokyowan no suishitsu to seitaikei ni oyobosu eikyo ni tsuite

    Kyozuka, Y.; Hu, C.; Hasemi, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hikai, A.


    The effect on the marine environment in the bay when a Mega-Float is installed in a bay was investigated. The physical process such as a residual flow (including tidal currents, water temperature, salt, density, and density currents), and the ecosystem model for which floating organic matter and plankton are handled were incorporated to develop a program for water quality calculation in a bay. The program was used for Tokyo Bay and compared with the conventional calculation result and the oceanograhpic observation result. Simultaneously, the effect on the Mega-Float was considered. On the flow in Tokyo Bay in summer, the calculation result that comparatively coincided with the observation value in a residual flow level was obtained. The horizontal distribution of COD comparatively coincides with the existing observation result. The influence that the Mega-Float exerts on the flow, water temperature, water quality, and ecosystem in the ambient sea area was little and local in the calculation scale (L {times} B {times} d = 6 km {times} 3 km {times} 2 m) of this time. However, the difference occurring due to the design position must also be investigated in future. 12 refs., 8 figs., 5 tabs.

  4. Design and model experiments on thruster assisted mooring system; Futaishiki kaiyo kozobutsu no thruster ni yoru choshuki doyo seigyo

    Nakamura, M.; Koterayama, W. [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics; Kajiwara, H. [Kyushu Institute of Technology, Kitakyushu (Japan). Faculty of Computer Science and System Engineering; Hyakudome, T. [Kyushu University, Fukuoka (Japan)


    Described herein are dynamics and model experiments of the system in which positioning of a floating marine structure by mooring is combined with thruster-controlled positioning. Coefficients of dynamic forces acting on a floating structure model are determined experimentally and by the three-dimensional singularity distribution method, and the controller is designed by the PID, LQI and H{infinity} control theories. A model having a scale ratio of 1/100 was used for the experiments, where 2 thrusters were arranged in a diagonal line, one on the X-axis. It is found that the LQI and H{infinity} controllers of the thruster can control long-cycle rolling of the floating structure. They allow thruster control which is insensitive to wave cycle motion, and efficiently reduce positioning energy. The H{infinity} control regulates frequency characteristics of a closed loop more finely than the LQI control, and exhibits better controllability. 25 refs., 25 figs.

  5. Topographical effects on wave exciting forces on huge floating structure. 2; Ogata futaishiki kaiyo kozobutsu ni sayosuru haryoku ni kansuru kenkyu. 2

    Imai, Y. [Hiroshima University, Hiroshima (Japan); Okusu, M. [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics


    A method to predict drift force acting on a floating structure has been developed for a marine structure consisting of a number of floating elements, positioned in a region having a slope at the sea bottom. When a huge marine structure, such as floating air port, is located in a coastal area, scale of the overall structure is very large, of the order of scale of water depth change. The new method assumes that a marine structure consisting of an infinite number of cylindrical floating elements is installed in parallel to the seashore, where symmetrical nature of the configuration allows to predict behavior of the whole system by analyzing one element. Integration of pressures acting on structure surfaces determines the horizontal component of the drift force acting on the structure. Being influenced by topography, drift force predicted peaks at a frequency different from that for the level predicted on the assumption of constant water depth. This indicates the necessity for consideration of seabottom slope and effects of broken waves at the seashore. 6 refs., 12 figs.

  6. NO2 observations over the western Pacific and Indian Ocean by MAX-DOAS on Kaiyo, a Japanese research vessel

    H. Takashima; Irie, H.; Y. Kanaya; F. Syamsudin


    Nitrogen dioxide (NO2) profile retrievals were performed by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) using a compact/low-power spectrometer on the Japanese research vessel Kaiyo during two ocean cruises around Japan and Japan–Bali (Indonesia)–Indian Ocean. DOAS analysis using a 425–450 nm fitting window revealed a clear land–ocean contrast in NO2 differential slant column densities (DSCDs) but poor fitting results and negative values, esp...

  7. Temperature and salinity profiles from high resolution CTD casts from the KAIYO-MARU in the North Pacific Ocean by the Fisheries Agency of Japan from 7 August 1996 to 01 October 1996 (NODC Accession 0000510)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected using a high resolution CTD in the North Pacific Ocean from the KAIYO-MARU from 7 August 1996 to 01 October 1996....

  8. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from Kaiyo in the Philippine Sea from 1994-02-12 to 1994-02-16 (NCEI Accession 0143635)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0143635 includes discrete sample and profile data collected from Kaiyo in the Philippine Sea from 1994-02-12 to 1994-02-16. These data include DELTA...

  9. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the North Pacific Ocean and Philippine Sea from 1996-06-17 to 1996-07-02 (NODC Accession 0115016)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115016 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the North Pacific Ocean and Philippine Sea from...

  10. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the East China Sea (Tung Hai) and Philippine Sea from 1996-06-20 to 1996-07-15 (NODC Accession 0115023)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115023 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the East China Sea (Tung Hai) and Philippine Sea...

  11. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the North Pacific Ocean and Philippine Sea from 1994-01-07 to 1994-02-10 (NODC Accession 0115007)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115007 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the North Pacific Ocean and Philippine Sea from...

  12. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU and MIRAI in the North Pacific Ocean from 1999-05-21 to 1999-09-10 (NODC Accession 0115168)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115168 includes biological, chemical, discrete sample, physical and profile data collected from KAIYO-MARU and MIRAI in the North Pacific Ocean from...

  13. NO2 observations over the western Pacific and Indian Ocean by MAX-DOAS on Kaiyo, a Japanese research vessel

    F. Syamsudin


    Full Text Available Nitrogen dioxide (NO2 profile retrievals were performed by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS using a compact/low-power spectrometer on the Japanese research vessel Kaiyo during two ocean cruises around Japan and Japan-Bali (Indonesia-Indian Ocean. DOAS analysis using a 425–450 nm fitting window revealed a clear land–ocean contrast in NO2 differential slant column densities (DSCDs but poor fitting results and negative values, especially at low elevation angles at low latitudes (2 volume mixing ratio (VMR data for the 0–1 km layer after applying our vertical profile retrieval method. In contrast, NO2 VMRs retrieved using fitting results from 460–490 nm are positive even at low latitudes, while they are reasonably similar to those obtained from 425–450 nm at mid-latitudes. Because NO2 DSCD for 425–450 nm shows a negative correlation with water vapor (H2O DSCD, the poor fitting appears to be due primarily to interference by H2O. We analyzed a 338–370 nm fitting window, which is free from H2O, and found good agreement between NO2 VMRs retrieved from 460–490 nm and 338–370 nm, even at low latitudes, at NO2 VMRs higher than ~0.2 ppbv. The results indicate that the background value of NO2 VMR over the western Pacific and Indian Ocean during the cruises was less than ~0.2 ppbv, with occasional enhancement to levels of ~0.2–0.4 ppbv.

  14. Tropical Ocean Climate Study (TOCS) and Japan-United States Tropical Ocean Study (JUSTOS) on the R/V KAIYO, 25 Jan to 2 March 1997, to the Tropical Western Pacific Ocean BNL component

    Reynolds, R.M.; Smith, S.


    The Japanese U.S. Tropical Ocean Study (JUSTOS) cruise on the R/V KAIYO in the Tropical Western Pacific Ocean was a collaborative effort with participants from the Japanese Marine Science and Technology Center (JAMSTEC), the National Center for Atmospheric Research (NCAR), and Brookhaven National Laboratory BNL. This report is a summary of the instruments, measurements, and initial analysis of the BNL portion of the cruise only. It includes a brief description of the instrument system, calibration procedures, problems and resolutions, data collection, processing and data file descriptions. This is a working document, which is meant to provide both a good description of the work and as much information as possible in one place for future analysis.

  15. Marine resources chemistry of magnesium. Magnesium no kaiyo shigen kagaku


    Marine water body covers 71% of the earth surface, and has an average depth of about 3700 m. This huge marine water body contains magnesium of 1300 ppm on average in its water. This paper describes research and development related to high-purity sea water magnesium oxide that could be produced from these marine resources. Effects of impurities in sea water, particularly removal of calcium and boron are the important subject for studying high-purity sea water magnesium oxide. This paper describes results of developing a decarbonation pretreatment method for reducing calcium impurities and an alkaline method to reduce boron impurities. Most methods of manufacturing magnesium from sea water in an industrial scale change magnesium hydroxide precipitated from sea water into MgCl2, and electrolyze it to obtain metallic magnesium. The paper shows results of the development of a method to recover magnesium hydroxide and basic magnesium carbonate using the lime-ammonium circulation process that uses salt making bittern as a raw material. 6 refs., 7 figs.

  16. International Ocean Symposium (IOS) 1996; Kokusai kaiyo symposium 1996



    This is a proceedings of the International Ocean Symposium 1996. On the first day of the symposium, the following were given with a theme `The Ocean, Can She Save Us`: Underwater research and future of mankind as a commemorative speech; The ocean, can she save us -- trying to discover the true figure of the ocean as a keynote speech. Panel discussion was held on The global environment and the infinite potential of the ocean. On the second day, an approach was made mostly from a cultural aspect with a theme `The Ocean and the Japanese.` The following were given: Human links between east and west as a commemorative speech; The ocean and Japanese culture as a keynote speech; Civilization spanning across oceans as a panel discussion. The Japanese have been developing their individual technologies in shipbuilding, shipping, and ocean development, have been raised by Mother Ocean, and have lived together. Ocean has been supplying humans food, water, oxygen, marine routes, and even dream and hope. The environmental pollution is the result of the human greediness. It is fear and friendship between humans and ocean that can save humans and ocean.

  17. Structural analyses of very large semi-submersibles in waves; Choogata hansensuishiki futai no harochu kozo oto kaiseki

    Iijima, K.; Yoshida, K.; Suzuki, H. [The University of Tokyo, Tokyo (Japan)


    An analysis method in which the technique of a vehicle obtained when a three-dimensional singular point distribution method and Kagemoto`s mutual interaction theory are combined was expanded for the fluid area was proposed as the structural analysis of very large semi-submersibles in waves. A partial structure method is used for the structure. In a fluid area, the number of unknown quantities appearing in a final expression could be largely reduced by introducing the new concept of a group body. In this process, both hydro-elasticity and hydrodynamic mutual interaction are considered. As a result, floating bodies that could not be previously calculated can be modeled as a three-dimensional frame structure and the response analysis in waves can be carried out without damaging the accuracy. The calculation result is used as the input data required for analyzing the structural fatigue locally during structural design of very large semi-submersibles in the 3,000 (m) class. This study can present a series of procedures between the response analysis of very large floating bodies in waves and the structural design. 11 refs., 14 figs., 1 tab.

  18. Effect of water pollution on marine organisms; Sekiyu osen no kaiyo seibutsu eno eikyo hyoka

    Ogata, M. [Okayama Univ., Okayama (Japan); Fujisawa, K. [Okayama Prefectural Fisheries Experiment Station, Okayama (Japan)


    Toxicity of petroleum component to aquatic organisms appears as a result of its deposition onto living organisms followed by its migration into bodies of the organisms, and emergence of toxicity from the migrated component. Effect evaluation processes standing on this viewpoint may include the exposure monitoring or migration monitoring, in which the petroleum component migrated into marine organisms is analyzed and the state of the component concentrated in these organisms is measured, or effect monitoring, in which actions of the petroleum component in the organisms are investigated. The effects of petroleum on aquatic organisms would include the following occurrence: direct fatal toxicity acting on cells and membranes, quasi-fatal toxicity causing death indirectly through feeding actions and abnormal actions, direct coating of oil on surface of organisms, which prevents movability and feeding actions of the organisms and reduces hydrophilicity of plumes and hairs, pollution of living organisms due to migration of carcinogenic aromatic compounds into bodies of the living organisms, and change in species compositions and geographic distribution of living organisms due to change in physico-chemical environment. This paper explains cases of detection and identification of organic sulfur compounds, aromatic compounds, polycyclic aromatic compounds, paraffins, olefins and heavy metals in parametric compounds of petroleum. 20 refs., 4 figs., 3 tabs.

  19. Habitat segregation of sessile marine organisms; Kaiyo fuchaku seibutsu no sumiwake

    Isoai, A. [Asahi Glass Co. Ltd., Tokyo (Japan); Kawahara, H.; Shizuri, Y.


    In order to develop the safe control agent of sessile marine organisms, the mechanism of habitat segregation of them has been investigated. Among various marine organisms, around 120 species of Porifera and Coelenterata accompanied with less the other sessile organisms were collected, to examine the adhesion prevention activity of their extracts against barnacles and Mytilus edulis. As a result, this activity was found out for 33% of Porifera and 27% of Coelenterata specimens. This means these organisms contain the adhesion prevention substances, and it is considered these chemical substances are practically used for the habitat segregation. Isolation structures of the chemical substances used for the habitat segregation were determined from these organisms. It was made clear that two acceptor genes successfully cloned from Balanus amphitrate are new G-protein coupling type acceptors having similar homology to the adrenaline and serotonin acceptors. 15 refs., 3 figs.

  20. Mathematical structure of ocean container transport systems; Kaiyo container yuso system no suriteki kozo ni tsuite

    Shinkai, A. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Chikushi, Y. [Nippon Telegraph and Telephone Corp., Tokyo (Japan)


    Mathematical structure of a vessel arrangement program was discussed in order to learn roles of container ships in ocean transport systems among China, NIES/ASEAN countries and Japan. Formulation is possible on a mathematical handling method for sailing route connection diagrams between ports, a transport network to indicate container movements, a service network to indicate sailing routes, and a network generalizing them. This paper describes an analysis made on the container transport system between Japan and China, taken as an example. Four ports were selected each from Japan and China, and the statistical database for fiscals 1996 and 1994 was utilized to set models for: (a) the liner network system with transshipment at the port of Shanghai and (b) the cruising route system going through the ports of Yokohama, Nagoya and Kobe. A hypothesis was set that a consortium (coordinated ship allocation) can be implemented ideally and completely. The transport network (a) is lower by 10% in total cost than the transport network (b), resulting in 1.6 times greater productivity. Actual service network is closer to the network (b), but the system can be utilized for discussing guidelines on vessel arrangement programs with which shipping companies pursue better management efficiency under a condition that the consortium can be formed. 10 refs., 6 figs., 2 tabs.

  1. Antifouling polymeric films against marine organisms. Kaiyo seibutsu fuchaku boshi to kobunshi

    Yamamori, N. (Nippon Paint Co. Ltd., Tokyo (Japan))


    An introduction is made on prevention of marine organisms from depositing on bridges and vessels, and on anti-fouling function of highly anti-fouling silicone resin and hydrolytic resins. First, in the case of silicone rubber, its surface is hydrophobic making it more difficult for sticking constituent (glycoprotein) in a depositing organism to deposit, in addition to its resilience, which sheds off easily the deposited organisms by its impact resilience. On the one hand, organism deposition can be prevented by means of micro-domain structure. Further, a description is given on the hydrolytic resins as to their anti-fouling agent releasing mechanism in hydrolytic paint film, and capability of prolonging the anti-fouling life by means of making the film thicker because the anti-fouling life is proportional to film thickness. In addition, explanations are given on elusion mechanism of hydrolytic resins, their behaviors in anti-fouling agent dispersion, the importance of controlling the elusion since the film elusion amount is an important factor to determine the release amount of the dispersed anti-fouling agent and the anti-fouling life, and the improvement of anti-fouling performance of the resins by means of adding monobasic acid into copper-acrylic resin. 9 refs., 13 figs., 8 tabs.

  2. Feasibility design of a floating airport and estimation of environmental forces on it; Futaishiki kuko no sekkei to kankyo gairyoku no suitei ni kansuru kento

    Inoue, Y.; Tabeta, S.; Takei, Y. [Yokohama National University, Yokohama (Japan). Faculty of Engineering


    A rough design was performed on a floating airport. On this floating structure, environmental external force was estimated, mooring design was carried out, and discussions was given on the position retaining performance important for airport functions and behavior of the floating structure. The discussion was given on cases that the airport is surrounded and not surrounded by floating breakwaters. A floating structure which becomes super-large in size requires considerations on force due to sea level gradient as a result of a tide. Deriving flow condition changes and force acting on the floating structure simultaneously by using numerical calculations makes it possible to estimate current force given with considerations on influence of the flow conditions created by installing the floating airport. Estimation was carried out by using a zone dividing method on wave drifting force acting upon the floating airport. As a result, it was found that installing floating and permeating type breakwaters can reduce the wave drifting force acting on the floating airport. The wave drifting force working on the floating airport can be reduced by installing the floating and permeating type breakwaters to lower levels than when no such breakwaters are installed. The airport may be moored with less number of fenders when the fenders of the same type are used. 18 refs., 10 figs., 5 tabs.

  3. Water balance of the oceans and the large rivers in the world. Sekai no daikasen to kaiyo ni okeru mizushushi

    Oki, T.; Mushiake, K. (The University of Tokyo, Tokyo (Japan). Institute of Industrial Science)


    Data for water balance of river basins and oceans were used for an investigation made on the annual water balance, especially on ratios of evaporation to precipitation, standing on global water circulation standpoint. The world river water balance data were used to seek classification of 70 river basins and precipitation amounts by preparing ground surface topographical data based on materials published by the National Geophysical Data Center (NGDC). The river water flow investigation used digital data published by the Global Runoff Data Center (GRDC). River water balance by oceans and lands in the world was calculated. This is an annual sum of atmospheric steam convergence, precipitations, evaporation calculated from the atmospheric water balance, and water runoff from lands into oceans. The paper shows on about 70 large rivers in the world their annual water balance, positions of estuaries in river basins, and amounts of precipitation and evaporation. Tropical areas have abundant precipitation, with evaporation efficiency at about 50%, while subtropical areas have majority of their precipitation evaporate, with very little runoff. 8 refs., 4 figs., 1 tab.

  4. On the sea-covering effect of a huge floating structure on the surrounding water; Choogata futai shuhen no kaisui ni taisuru kaimen shahei no eikyo ni tsuite

    Fujino, M.; Kagemoto, H.; Hamada, T. [The University of Tokyo, Tokyo (Japan)


    The numerical analysis program based on the difference method for dynamics of sea water with sea-surface displacement, flow rate, salt content and temperature as the parameters is modified to more accurately assess the effects of a huge marine structure on surrounding environment by adding the effects of insolation and boundary conditions of the sea-covering effects of the floating structure. The numerical simulation was done for summer and winter seasons, not in a sea area but using a rectangular bay with the floating structure at the center. A new flow evolves around the floating structure, due to the sea-covering effect. The flow patterns in summer and winter are clearly different, due to difference in insolation. The predicted flow is also sensitive whether stratification is considered or not, by which is meant that it is important what stratification effect is taken into account. Daily insolation changes are accompanied by vertical distribution of water temperature and its temporal change. These effects are also observed under the floating structure which shields insolation. 10 refs., 17 figs., 4 tabs.

  5. Basic investigation on deflection wave propagation and strength of very large floating structures; Choogata futai kozo no tawami hado denpa kyodo to kyodo ni kansuru kisoteki kosatsu

    Tsubogo, T.; Okada, H. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering


    The response strength in which deflection waves propagating in the elastic body of a large floating structure with an order of km in length and width was investigated. Attention was paid to the waves propagating the place fully away from the boundary of a very large floating body so as to obtain the dispersion relation of waves and the relation between incident waves and deflection waves. Next, the frequency response was checked from the aspect of the displacement amplitude and strength for beams and plates. The dispersion relation of waves propagating the place fully away from the boundary of a very large floating body and the relation between the waves and infinite-point incident waves were represented by an expression. Similarly, the waves propagates more than the infinite-point incident waves in frequency, wavelength, and speed. A lower-limit value exists in the propagation speed. The displacement and stress amplitudes are represented by a relational expression. For plates, the displacement amplitude increases when the wave direction coincides with the small-rigidity direction. The stress amplitude is maximized when the waves corresponding to the ``wave below a floating body = size of a characteristic wave number`` reach the large-rigidity direction. 10 refs., 10 figs., 2 tabs.

  6. On the prediction of hydroelastic behaviors of a huge floating structure in waves. 2nd Report; Choogata futai no harochu dansei kyodo no suiteiho ni tsuite

    Murai, M.; Kagemoto, H.; Fujino, M. [The University of Tokyo, Tokyo (Japan)


    On the hydroelastic behaviors of a huge floating structure, a mutual interaction theory based on the area division method is used for the analysis of a fluid problem and a mode analysis method is used for the analysis of deformation. On the continuous deformation of a floating structure, the structure is considered as a set of partial structures obtained when the plane shape was divided into squares and discretely handled as a series of rigid motions in the small partial structures obtained by dividing the partial structures more finely. The experimental result in a water tank and the distribution method at a singular point were compared on the deformation of the elastic floating structure estimated by calculation based on this formulation. The result showed that the estimation method on the hydroelastic problem proposed in this paper is valid. On the prediction of hydroelastic behaviors of a huge floating structure, various calculation examples indicate that the hydroelastic behavior is not only the relation between the structure length and wavelength, but also that the bending rigidity of a structure is a very important factor. For a huge floating structure in the 5,000 m class, up to shorter wavelength of about {lambda}/L = 1/100 must be investigated. 6 refs., 14 figs., 5 tabs.

  7. Numerical response analysis of a large mat-type floating structure in regular waves; Matogata choogata futai kozobutsu no haro oto kaiseki

    Yasuzawa, Y.; Kagawa, K.; Kitabayashi, K. [Kyushu University, Fukuoka (Japan); Kawano, D. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)


    The theory and formulation for the numerical response analysis of a large floating structure in regular waves were given. This paper also reports the comparison between the experiment in the Shipping Research Institute in the Minitry of Transport and the result calculated using numerical analytic codes in this study. The effect of the bending rigidity of a floating structure and the wave direction on the dynamic response of a structure was examined by numerical calculation. When the ratio of structure length and incident wavelength (L/{lambda}) is lower, the response amplitude on the transmission side becomes higher in a wave-based response. The hydrodynamic elasticity exerts a dominant influence when L/{lambda} becomes higher. For incident oblique waves, the maximum response does not necessarily appear on the incidence side. Moreover, the response distribution is also complicated. For example, the portion where any flexible amplitude hardly appears exists. A long structure response can be predicted from a short structure response to some degree. They differ in response properties when the ridigity based on the similarity rule largely differs, irrespective of the same L/{lambda}. For higher L/{lambda}, the wave response can be easily predicted when the diffrection force is replaced by the concentrated exciting force on the incidence side. 13 refs., 14 figs., 3 tabs.

  8. On the estimation method of hydrodynamic forces acting on a huge floating structure; Choogata futai ni hataraku haryoku ryutairyoku no suiteiho ni kansuru kenkyu

    Kagemoto, H.; Fujino, M.; Zhu, T. [The University of Tokyo, Tokyo (Japan)


    A floating structure such as an international airport is anticipated to have a length of about 5,000 m and a width of about 1,000 m. A singular point method may be used as a method to estimate force that such a floating body is subjected to from waves. In order to derive a solution with practically sufficient accuracy, 1250 elements are required in the length direction and 250 elements in the width direction, or a total of 312,500 elements. Calculating this number of elements should use finally a linear equation system handling complex coefficients comprising 312,500 elements, which would require a huge amount of calculation time. This paper proposes a method to derive solution on wave forces acting on a super-large floating structure or fluid force coefficients such as added mass coefficients and decay coefficients at a practically workable calculation amount and still without degrading the accuracy. The structure was assumed to be a box-shaped structure. Strengths of the singular points to be distributed on each element were assumed to be almost constant except for edges in lateral, oblique and longitudinal waves. Under this assumption, the interior of the floating structure excepting its edges was represented by several large elements to have reduced the number of elements. A calculation method proposed based on this conception was verified of its effectiveness. 2 refs., 25 figs., 3 tabs.

  9. Production of icosapetaenoic acid from marine bacteria and its genetic engineering; Kaiyo saikin ni yoru EPA n seisan to idenshi kogaku

    Yazawa, K.; Yamada, A. [Sagami Chemical Research Center, Kanagawa (Japan)


    A marine bacterium, judged as a new species close to Shewanella putrefaciens, was isolated from the intestinal contents of the Pacific mackerel. The isolated strain SCRC-2728 produced EPA as a sole polyunsaturated fatty acid amounting to 25-40 % of the total fatty acid in the cells. EPA existed as phospholipids in the cell and was found in the sn-2-position of phosphatidyl ethanolamine and phosphatidyl glycerol. The physiological activity of the EPA-phospholipids extracted from SCRC-2738 cells was examined following administration to stroke-prone spontaneously hypertensive rats. After four weeks of oral administration, serum lipids (cholesterol, triacylglycerol and phospholipid) and the systolic blood pressure were reduced significantly, compared to the control rats fed soybean lecithin. Moreover, we observed a significant reduction of the weight of perirenal and paraepididymal adipose tissues (26-38 %). The 38 kbp genom DNA fragment was cloned from SCRC-2738 and expressed in Escherichia coli, which resulted in the production of EPA. The nucleotide sequence of the 38 kbp DNA fragment was determined. The DNA fragment contains eight open reading frames, and three of them possess homology with enzymes involved in fatty acid synthesis. 18 refs., 9 figs., 2 tabs.

  10. Experiments of off-shore ocean thermal energy conversion system in sea area at Toyama bay. Toyamawan ni okeru yojogata kaiyo ondosa hatsuden system no jitsukaiiki jikken

    Takazawa, H.; Amano, M.; Kajikawa, T. (Electrotechnical Laboratory, Tsukuba (Japan))


    Because of the fact that the sea water in the Toyama Bay has water temperature difference of more than 20 {degree}C between at the surface layer and the deep layer, and the water scooped up from the deep layer has a nutritious salt effect beneficial to the local fishery, an applicability of the ocean thermal energy conversion was experimented at the actual sea area. The evaporator used as an energy self-supply equipment rated at 3.5 kW output is a hybrid type, in which a spray surface evaporation is carried out in the same shell as for a pool boiling. The condenser is of a perpendicularly flowing membrane condensation type. The heat transfer pipes in these heat exchangers use aluminum alloy material, with the interior processed with sea water resistant resin. The evaporator has eight spray nozzles for the working fluid, which are so arranged that the fluid jetting distributes the fluid uniformly over the whole heat transfer pipes, and the optimum amount of circulation was 10 tons/h. Heat transfer pipes for the condenser had the heat transfer performance reduced to half because of being resin coated. Itis necessary to reduce contact resistance especially between the resin and the base material. Since the evaporator {prime}S heat exchanging performance is decreased in about 15 days when conraminated biologically, the unit should preferably be cleaned within that period of time. An output of 3 kW was obtained at a temperature difference of 20 {degree}C, which suggests that the system can be self-supplied of the required energy if the sea water is scooped from the deep layer at a rate of about 0.3 ton per second. 7 refs., 7 figs., 1 tab.

  11. Development of an observation robot `Flying Fish` for comprehensive measurements of ocean environment; Kaiyo kankyo sogo kansoku robot `flying fish` no kaihatsu kenkyu

    Koterayama, W.; Yamaguchi, S.; Nakamura, M. [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics; Akamatsu, T. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)


    With an objective for spatial continuous measurement of physical, chemical and biological amounts in ocean, development has been made on a wing controlled towed vehicle, `Flying Fish` which is capable of controlling depth, pitch and roll. Numerical simulations and two-year sea experiments have been carried out for the development. Flying Fish consists of a sub-system comprising a towing vehicle, towing cables, and on-board controllers. In a steady state, Flying Fish can be controlled at accuracy for depth of {plus_minus} 0.05m, pitch of {plus_minus} one degree, and roll of {plus_minus} 0.5 degree. This accuracy is sufficient for operating a chemical analyzer, the dissolved carbonic acid analyzer. Even in a non-steady state such as in changing the depth, the pitch can be controlled at {plus_minus} 3 degrees and the roll at {plus_minus} 0.5 degree. This extent of attitude change is within a range rendering no problems in maintaining accuracy of the measurement devices. The result of sea experiments for movements of Flying Fish agreed with that of the numerical simulation at practically usable accuracy. Flying Fish is verified as an effective system in investigating spatial variations in ocean data. 10 refs., 15 figs., 1 tab.

  12. Investigations during fiscal 1995 on capability of oceans to absorb and fix carbon dioxide; 1995 nendo kaiyo no nisanka tanso kyushu kotei noryoku no chosa



    Investigations were given on capability of oceans to absorb and fix carbon dioxide as part of measures to prevent global warming. Carbon dioxide absorption and fixation in oceans relate to biological and chemical processes, whereas parameter dependence of each process was investigated. In relation to dissolution and dissociation of carbon dioxide into oceans, the parameter that governs exchange of carbon dioxide between atmosphere and ocean is partial pressure of carbon dioxide in surface sea water. This partial pressure is largely affected by water temperature, total carbonic acid and alkalinity. Particle-shaped organic carbon (detritus) is formed mainly by withering of photoplanktons. Formation of calcium carbonate due to activities of living organisms increases the carbon dioxide partial pressure. Fluxes of detritus are predominant among the whole precipitation flux in carbon circulation, which are more than two times the precipitation flux of photoplanktons. Particles are turned into inorganics by bacteria during the precipitation process. 29 refs., 21 figs., 6 tabs.

  13. Comparative study of hydroelastic responses of semisubmersible type and pontoon type very large floating structure in waves; Tachushiki semisabugata to pontoon gata choogata futai no harochu dansei oto no hikaku

    Ma, N.; Hirayama, T.; Sato, N. [Yokohama National University, Yokohama (Japan). Faculty of Engineering


    A semisubmersible very large floating structure is compared with an equivalent pontoon type in vertical displacement and longitudinal bending moment in waves. The theoretical calculation is based on the mode synthesis method, and fluid force is analyzed by the three-dimensional singularity method for the symmetric structure, in which the effects of elastic deformation are taken into account. The semisubmersible and pontoon types are not much different from each other in eigenfrequency and mode shape in the dry mode. In the wet mode, on the other hand, the pontoon type is characterized by the synthetic mode in which torsional and bending modes overlap each other, each mode having a similar eigenfrequency. These types are different in elastic response, the pontoon type having several tens times higher coefficient of attenuation than the semisubmersible type. The pontoon type is generally lower in response, but its torsional mode is excited in transverse waves, making it higher than the semisubmersible type at near eigenfrequency of this mode. 15 refs., 17 figs., 2 tabs.

  14. Structural response analysis of very large floating structures in waves using one-dimensional finite element model; Ichijigen yugen yoso model ni yoru choogata futai no harochu kozo oto kaiseki

    Fujikubo, M.; Yao, T.; Oida, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering


    Formulation was made on a one-dimensional beam finite element which is effective in analyzing structural response of very large floating structures by modeling them on beams on an elastic foundation. This element allows strict solution of vibration response in the beams on the elastic foundation to be calculated efficiently for a case where mass and rigidity change in the longitudinal direction. This analysis method was used to analyze structural response of a large pontoon-type floating structure to investigate mass in the end part for the structural response and the effect of decay while passing the structure. With a pontoon-type floating structure, reduction in bends and bending stress in the end part of the floating structure is important in designing the structure. Reducing the mass in the end part is effective as a means to avoid resonance in these responses and reduce the responses. Increase in rigidity of a floating structure shifts the peak in quasi-static response to lower frequency side, and reduces response in resonance, hence it is advantageous for improving the response. Since incident waves decay while passing through the floating structure, response in the lower wave side decreases. The peak frequency in the quasi-static response also decreases at the end part of the structure in the upper wave side due to decay in wave force. 7 refs., 11 figs., 1 tab.

  15. Basic studies on design supporting system of offshore structure. Part 2. Implementation of structural design supporting system of offshore structures; Kaiyo kozobutsu wo taisho to shita sekkei shien system ni kansuru kisoteki kenkyu. 2. Kaiyo kozobutsu no kozo sekkei shien system no kochiku

    Nomoto, T.; Hamada, K.; Aoyama, K. [The University of Tokyo, Tokyo (Japan)


    In order to improve the existing design-supporting system for offshore structures, new functions are added to evaluate information of the products, especially those for structural designs. The structural analysis system should be provided with a function of design modification, to efficiently support the structural analysis of these structures. The new system adds hierarchy of various offshore structure models and three-dimensional dimensions to clarify structural and geometrical constraints and design-modification function. The design-modification function is included by use of the hierarchy. The other new functions are finite element analysis systems for the main structure and components, and rigidity calculation for the main structure. The main structure and functional element models are confirmed to be useful also for utilization of information, and provide necessary information of the product models. 11 refs., 11 figs.

  16. Studies on marine ecosystem in particular emphasis on phytoplankton (lecture by the member awarded the oceanographic society of Japan prize for 1992). Shokubutsu plankton wo chushintoshita kaiyo seitaikei ni kansuru kenkyu

    Takahashi, M. (The University of Tokyo, Tokyo (Japan). Faculty of Science)


    This paper, while introducing major study results of the author, summarizes his studies on ecosystems in lakes and oceans with respect mainly to phytoplanktons. The studies include the following subjects: A proposal on mathematical model equations to estimate growth of photosynthetic bacterial populations in deep lake beds; evaluation of stimulative effects for photosynthetic production provided by fertilizer application in lakes, and influences of phytoplanktons on population structures; evaluation on effects imposed on ecosystems from dumping chemical substances, as observed in experimental ecosystems that incorporate part of marine ecosystems; correlation between red-tide life absorbing proliferation stimulating substances and red tide generation; growth of high-concentration phytoplankton populations containing algae as a dominant species in local upwelling environments in oceans; and verification on establishment of specific phytoplankton populations containing pico-phytoplankton as a dominant species in oligotrophic environments in open seas. The paper mentions influences of the author's book, Biological Oceanographic Processes under joint authorship with Parsons on marine ecosystem researchers. 66 refs., 8 figs.

  17. Evaluation of sea-state using images from satellite remote-sensing. Discrimination of cloud-system using GMS images; Eisei gazo joho wo mochiita kaiyo haro no haaku. Himawari gazo wo mochiita kumo no bunrui

    Yamada, T.; Hosoda, R. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering


    Items of information are analyzed as derived from remote sensing data by using the stationary meteorological satellite `Himawari` as a platform to propose a discrimination model for oceanic meteorology or clouds closely related to oceanic meteorology. Cloud system regions are extracted by combining visual and infrared images to investigate natures of each of cloud top altitude, cloud system thickness, inclination of the cloud system edge, and complexity of the cloud system edge as parameters to represent characteristics of the cloud systems. It was shown that, by applying the fuzzy theory to the result therefrom, cloud type discrimination models can be structured. As a conclusion, a proposal was made on a cloud system analyzing model capable of making evaluation close to that by skilled analyzers. Application of the fuzzy theory to the cloud analyzing models makes it possible to reduce different kinds of ambiguity the clouds themselves have, and the effects of analyzer attributable ambiguity which may get mixed in during an analyzing process. Introduction of fuzzy integration and fuzzy measure has made it possible to express the evaluation result by such quantitative parameters as the cumulus and stratus degrees. 8 refs., 10 figs., 2 tabs.

  18. Proceedings of the Spring Meeting of the Society of Naval Architects of Japan (1996). Part 1. Resistance, propulsion, advance, and ocean; Nihon zosen gakkai (1996 nen) shunki koen ronbun maezuri. 1. Teiko, suishin shindo, kaiyo



    This is a proceedings of the Spring Meeting of the Society of Naval Architects of Japan made public on May 15 and 16, 1996. In the basic research, the following were included: Numerical simulation for submerged body fitted with hydrofoil; Simulation of tandem hydrofoils by finite volume method with moving grid system; Determination of the unknown method surface of planning plates by a formulation based on high aspect ratio approximation; Numerical simulation of a bubble flow by modified density function method, etc. As to floating bodies, Response characteristics of a long life type floating offshore airport in waves (3rd report: Response due to short waves and an attempt of active inclination control); Feasibility design of a floating airport and estimation of environmental forces on it; On the estimation method of hydrodynamic forces acting on a huge floating structure, etc. In addition, A numerical prediction with `DMDF` model of pack ice motion in the Okhotsk Sea; Development of an observation robot `Flying Fish` for comprehensive measurements of ocean environment; Water entry simulation of free-fall lifeboat, etc.

  19. Fiscal 2000 survey report. Basic research on metallic peptides in marine organisms and microbes; 2000 nendo kaiyo seibutsu oyobi biseibutsu no kinzoku ketsugo pepchido ni kansuru kisoteki kenkyu hokokusho



    Research is conducted to collect findings on new metallic peptides and proteins which will work effectively in the bio-remediation of heavy metal pollution and in the collection of useful metals. In this fiscal year, primary evaluation methods for metal resistant bacteria are prepared so as to discover new metallic peptides, sampling was carried out at four sites which are characteristically different from each other, and more than 100 strains of metal resistant bacteria were obtained. Out of them, Ni enriched bacteria whose growth is accelerated in the presence of Ni and like others were found out. In another effort, a high concentration Cr resistant bacterium was examined, and it was learned that it exhibits its resistance by reducing hexavalent Cr to trivalent Cr. The denaturing gradient gel electrophoresis (DGGE) method was applied to the analysis of a culture process involving metal addition and accumulation, and the result indicated that a study of details of accumulation culture conditions would be necessary to find out strains that remain undiscovered. It is expected that peptides equipped with sophisticate functions may be obtained when details including sampling points are studied and the result is fed back to the sampling process. (NEDO)

  20. HELIUM, PARTICULATE ORGANIC CARBON and other data from HEIYO, KAIYO and other platforms in the NW Pacific, Philippine Sea and East China Sea from 1939-08-17 to 1988-09-27 (NCEI Accession 9000197)

    National Oceanic and Atmospheric Administration, Department of Commerce — A tape containing part of the annual exchange of chemical data from the Japan Oceanographic Data Center collected from East China Sea (Tung Hai), Philippine Sea, NW...

  1. Response characteristics of a long life type floating offshore airport in waves. 3rd Report. Response due to short waves and an attempt of active inclination control; Chojumyogata futaishiki kaijo kuko no harochu oto tokusei. Tanhachoiki no oto oyobi shisei seigyo no kokoromi

    Hirayama, T.; Ma, N.; Nishio, O.; Sato, N. [Yokohama National University, Yokohama (Japan). Faculty of Engineering


    Notice was given on response characteristics in a short wavelength range of a large floating structure for an offshore airport consisting of semi-submersible replaceable type units, and influence of unit lacking. An attempt was also made on performing restoration of inclination change during unit lacking and suppression of long-cycle variation in waves by using air pressure control. The result of a numerical calculation based on a three-dimensional singular point method may be summarized as follows: mass force added vertically on columns in short wavelength range differs in the outer edges and the central part; relatively uniform values are shown in the central part; and interactive interference is recognized in wave forces in the vertical direction, but the influence therefrom decreases as the wave length decreases. Calculations on vertical movements and bending moments in waves were performed by using a mode synthesizing method. The calculations used fluid force which was calculated based on the three-dimensional singular point method utilizing symmetry with respect to each condition for a complete model plus unit lacking and unit lacking plus inclination control. As a result of verifying the calculations by using an experiment, relatively good agreement was achieved in either case. A high-frequency vibration experiment made clear the characteristics of elastic response in the short-wave length range. 14 refs., 14 figs.

  2. Consideration on the dynamic behavior and the structural design of large scale floating structure. 2nd Report. Stability of elastic structure and design of elastic response; Choogata futai no kozo kyodo oyobi kozo sekkei ni kansuru kosatsu. 2. Dansei henkei wo koryoshita fukugensei oyobi kozo oto no sekkei

    Suzuki, H.; Yoshida, K. [The University of Tokyo, Tokyo (Japan)


    A policy of improving a very large floating body was planned based on its dynamic characteristics, and a proposal was made thereon. Furthermore, discussions were given on stability that considers effect of elastic deformation required when a structure is mounted on a floating body. With respect to a structural design of a very large floating body in which elastic response is governing, and upon modeling the very large floating body into an aeolotropic plate on an elastic supporting floor, it was shown that the existing range of natural vibration speed in the elastic response is in higher range than the natural vibration speed of heave. It was also indicated that the peak height of response to waves in resonance is inversely proportional to wave frequency, and furthermore, degree of flowing in of vibration energy during the resonance is determined by an inner product of spatial vibration patterns of wave force and the excited mode shape. A proposal was made on a floating body improved of excessive response in the floating body edges by changing the characteristics of the floating body edges. In addition, discussions were given on stability that considers elastic deformation of a floating body that becomes necessary when a structure, such as a building, is built on a very large floating body. 9 refs., 9 figs., 3 tabs.

  3. Outline of biological surveys around planned waste dumping site off Japan conducted by Tokai Regional Fisheries Research Laboratory

    The biological surveys were conducted by the R/V Kaiyo-Maru during 1972 - 1974 in and around the proposed dumping site in the Northwest Pacific Basin. The sampling was made by diverse kinds of gears to collect various size spectra of various ecological group of marine fauna. Some of biological result obtained by this survey is reviewed

  4. Study of internal wave generation by tide-topography interaction; Lecture by the member awarded the Okada Prize of the Oceanographical Society of Japan for 1989. Choryu niyoru naibuha no hassei kiko ni kansuru kenkyu; 1989 nendo Nippon kaiyo gakkai Okadasho jusho kinen koen

    Hibiya, T. (Univ. of Tokyo (Japan). Earthquake Research Inst.)


    With regard to internal waves under strong tidal flows generated in the Amakusanada, Kyushu, the Canadian West Coast Region and the U.S. Eastern Coast Region, this study explains the theory of their generation mechanism showing the examples of its applicayion to the actual maritime regions, then by developing this theory, discusses the role of its vertical shear effect in the generation process of internal waves in case where the stationary two layer alternative flow lies on top of a strong tidal flow like the inside of straits and fjords, etc.. Furthermore, it clarifies the effect of the vertical mixing on the seawater alternating process inside and outside of the fjord taking place on the both sides of the above mixing when such a vertical mixing is caused by breaking waves of the internal tidal flows over a sill in the fjord, as an example of an important role taken by the internal waves with large wave heights thus generated. 28 refs., 12 figs.

  5. Study of thermal threshold and counter-measures for human body in oceanic working environment. 1st Report. Heat balance model and heat storage index; Shonetsu kankyoka no kaiyo sagyo ni okeru netsuteki genkai to onnetsu taisaku ni kansuru kenkyu. 1. Netsu shushi model to onnetsu shisu

    Fukuchi, N. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Nakamura, M. [Tokyo Gakugei University, Tokyo (Japan); Murayama, M.


    Identification was intended on effects of such thermal factors as metabolic amount, environmental temperature and humidity, and clothing resistance on human body temperatures during works under hot environments. Therefore, measurements were carried out on human skin temperatures, rectum temperatures and humidity inside clothing, while amount of motion, environmental temperature, and clothing are changed in a constant temperature room and under a sun irradiation environment. Furthermore, a heat balance model was prepared, which divides the objects into an outer shell layer whose temperature changes depending on the result of this experiment and into a core having constant temperature characteristics. An equation to derive skin temperatures was introduced from the model. The equation formulated a calculation formula for heat accumulation in human body, which can be used as a hot heat index. Relationship between thermal factors and heat storage amount was investigated to consider a thermal limit for a physical work. An equation to derive skin temperatures was confirmed capable of expressing general change in skin temperatures, being proved by comparison with experiments. Calculation formulas for amount of heat stored in human body were shown capable of expressing influence of different thermal factors, the expression being useful as a hot heat index. Calculating the human body heat storage is very largely affected by effect of sweat to dissipate heat, hence it is necessary to improve the accuracy including that for body temperature adjusting reactions. 17 refs., 17 figs., 5 tabs.

  6. Distribution and biology of epipelagic animals in the northern North Pacific Ocean and adjacent seas-I. Fishes and squids in the southern Okhotsk Sea and western North Pacific Ocean off the Kuril Islands in the autumn of 1993

    Nagasawa, Kazuya; Ueno, Yasuhiro; Azuma, Teruo; OGURA, Miki(College of National Rehabilitation Center for the Disabled); Startsev, Alexander V.; Ivanova, Irena M.; Morris, John F. T.


    A surface-trawl survey was conducted by the R/V Kaiyo mare in the southern Okhotsk Sea and western North Pacific Ocean off the Kuril Islands in October and November 1993. The distributions and abundances of the species caught are described and discussed. Twenty-four fish species (1 lamprey, 1 shark, and 22 teleosts) and one squid species were identified. Juvenile Pacific salmon (6 species of the genus Oncorhynchus) were the most abundant, followed by myctophids, juvenile arabesque greenling (...

  7. Morphology and distribution of heterotrophic protists along 75゜E in the Southern Ocean



    Seawater samples were collected from the 0 and 50m layers along the transect of 75°E in the Indian sector of the Southern Ocean in the austral summer of 1983-84 during the BIOMASS SIBEX I cruise of the R. V. KAIYO MARU of Japan Fisheries Agency. Distribution and taxonomy of heterotrophic protists were investigated. Naked amoebae and choanoflagellates were the dominant heterotrophic protists in the Indian sector of the Southern Ocean. The total cell volume of heterotrophic protists was larger ...

  8. Exploration of Teisi Knoll by Autonomous Underwater Vehicle "R-One Robot"

    Ura, Tamaki; Obara, Takashi; Nagahashi, Kenji; Nakane, Kenji; Sakai, Shoji; Oyabu, Yuji; Sakamaki, Takashi; Takagawa, Shinichi; Kawano, Hiroshi; Gamo, Toshitaka; Takano, Michiaki; Doi, Takashi

    This paper outlines the exploration of Teisi Knoll by the autonomous underwater vehicle the R-One Robot, as carried out October 19-22, 2000, and presents images taken by the sidescan SONAR fitted to the bottom of the vehicle. The R-One Robot was launched from the R/V Kaiyo, started diving near the support ship, followed predetermined tracklines which were defined by waypoints, and finally came back to the destination where it was recovered by the support vessel. In order to minimize positioning error, which is determined by the inertial navigation system and Doppler SONAR, the robot ascended to the surface several times to ascertain its precise position using the global positioning system, the antenna of which is fitted on the vertical fin. Taking advantage of this positioning system, the robot followed the predetermined tracklines with an error of less than 40 meters in 30 minutes of continuous submerging. Disturbance to the robot is small enough compared to towed vehicles that its movement can be regarded as stable. This stability resulted in clear side scanning images of the knoll and surrounding sea floor. The robot stopped at the center of the knoll, and descended vertically into the crater. When the vehicle was in the crater, anomalous manganese ion concentrations were detected by the in situ trace metal micro-analyzer GAMOS, which was loaded in the payload bay at the front of the robot.

  9. Estimation of hydrothermal deposits location from magnetization distribution and magnetic properties in the North Fiji Basin

    Choi, S.; Kim, C.; Park, C.; Kim, H.


    between the low magnetization zones and the analytic signals is considered that the submarine magnetic strength of KF-3 is lower than that of KF-1 and KF-2. The spreading ridges of the study areas showed common Central Anomaly Magnetization Highs (CAMH). As a whole, the previous studies on the structure of this study area (Auzende et al, 1990) support our results of the magnetic properties (Magnetic Anomaly and RTP). We can expect to have the better results by comparing with the other study like geophysics (seismic), geology, and geochemistry in this area. Reference Auzende, J.M., and 29 others, Active Spreading and Hydrothermalism in North Fiji Basin(SW Pacific). Results of Japanese French Cruise Kaiyo 87, Marine Geophysical Researches., 12, 269-283, 1990.

  10. Development of precision acoustic transponders for GPS/Acoustic observation on the deep seafloor near the Japan Trench axis

    Fujimoto, H.; Kido, M.


    The 2011 Tohoku-oki earthquake has let most of researchers recognize the importance of seafloor geodetic observation, especially near the trench axis. Iinuma et al. (2012a) estimated the coseismic slip distribution combining onshore GPS data with the seafloor geodetic data. Their results reveal that a huge (> 50 m) slip occurred in a small area (about 40 km in width and 120 km in length) near the Japan Trench and generated the huge tsunami. After the Tohoku-oki earthquake, seismic coupling near the trench axis has become a key to understand giant earthquakes in subduction zones, and it is GPS/Acoustic (GPS/A) repeated seafloor positioning that can give an observational constraint to it. Observation of postseimic deformation is another and urgent task required in the Japan Trench. Seafloor geodetic observation indicates posteseimic deformation near the Japan Trench axis in the north and south of the huge slip area (Iinuma et al., 2012b). The result is clearly different from that of onshore GPS observation. Postseismic deformation is estimated to be a key observation that can discriminate proper models from several ones that can explain the occurrence of the mega thrust. Tohoku University plans to deploy extensive GPS/A observation array along the Japan Trench in 2012 with a fund from MEXT, Japan, to cope with these requests (Kido et al., in this meeting). Precision acoustic transponders have newly been developed for the array to enable the following three requests: (1) observation on the deep seafloor, (2) compatibility among three institutions in Japan, and (3) observation for ten years. The first is the observation on the deep seafloor near the trench. While the Japan Trench axis is deeper than 7000 m, the existing GPS/A sites along the Japan Trench have remained on the seafloor shallower than 2500 m except the one nearest to the trench, where we observed coseismic slip of 31 m (Kido et al., 2011). We deployed 4 units of the new transponders supplied by Kaiyo