Sample records for choogata futai shuhen

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Diversité et structure des communautés de Lépidoptères nocturnes en chênaie de plaine dans un contexte de conversion vers la futaie régulière

    Bonneil, Philippe


    La gestion forestière durable nécessite d'évaluer l'impact des traitements et des pratiques sylvicoles sur la biodiversité. Dans les forêts domaniales françaises, les anciens taillis-sous-futaie de chêne sont convertis vers la futaie régulière dont la surface s'agrandit, et sont donc voués à disparaître dans les décennies à venir.Dans ce contexte, nous avons étudié l'impact à court terme de deux types de coupes d'intensités différentes (la coupe d'ensemencement et la coupe d'éclaircie), ainsi...

  10. 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.

  11. Etude bioclimatique d'une futaie feuillue (Fagus silvatica L. et Quercus sessiliflora Salisb.) de l'Est de la France III. - Potentialités photosynthétiques des feuilles à différentes hauteurs dans le peuplement

    Ducrey, Michel


    Pour étudier la photosynthèse nette dans une futaie feuillue, on a prélevé des rameaux de hêtre et de chêne à 10 hauteurs différentes dans le peuplement. Les courbes de photosynthèse nette en fonction de l’éclairement ont été établies en laboratoire grâce à une enceinte d’assimilation climatisée et régulée en température, en humidité et en gaz carbonique. Pour le hêtre, la photosynthèse nette maximale par unité de surface foliaire augmente avec l’éclairement de croissance : elle est pl...

  12. Systematic analysis on mooring systems of floating structures; Futai keiryuho ni kansuru keitoteki kenkyu

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


    Discussed herein are mooring performance requirements of the new types of marine structures now proposed, and characteristic ranges and future expansion potential of the existing mooring systems. The mooring systems studied for floating structures are catenary, single point (multi-leg and single-leg types), fixed structure with fender and tension leg mooring systems. The studied items include extraction of the elements that constitute rigidity of the spring for horizontal mooring, survey on and data collection for each element, determination of element ranges, programs for mooring analysis, assessment of mooring characteristic ranges, and potential development of the characteristic ranges. It is concluded that the existing systems with their current characteristic ranges and future possibility are insufficient for the future marine structures. It is therefore necessary to develop new mooring concepts, instead of expanding the current concepts, in order to meet the mooring performance requirements for the new marine structures. 14 refs., 9 figs., 11 tabs.

  13. Evaluation on the effect of tsunami and seaquake on the floating structure; Tsunami kaishin no futai ni taisuru eikyo hyoka

    Yoshida, K.; Suzuki, H.; Hosomi, I. [The University of Tokyo, Tokyo (Japan); Nahata, H. [The Long-Term Credit Bank of Japan, Ltd., Tokyo (Japan)


    The effects of tsunami and seaquake on large floating structures are theoretically studied, where these effects are followed in terms of local strength using the equation proposed by Sells to predict surface shapes changed by seaquake-caused uplift of the seabottom. The equation is combined with the one for tsunami propagation, to better predict the tsunami motion. The simulation results indicate the necessity of considering the effects of tsunami for the design of a large floating structure. The authors discuss that the effect of tsunami is minimized when a floating structure is set at a depth of at least 40 to 50m, chain length should be determined by equalizing the breaking weight with the load at which the structure starts to move, and a structure should be set at a position where it is not attacked by transverse waves. They also discuss that seaquake intensity should be predicted by the equation of motion of compressible fluid, and, noting local strength of a floating structure, it will not be damaged when it is at least 16mm thick under the conditions of 2m as seabottom uplift and 0.5m as draft depth. 15 refs., 9 figs., 2 tabs.

  14. Wave-free floating body forms for a shallow sea area; Senkaiiki no naminashi futai keijo ni tsuite

    Kyozuka, Y.; Nariai, Y. [Kyushu University, Fukuoka (Japan)


    In column footing or semi-submergible type marine structures, a vertical wave force vanishes at a specific period of waves. This phenomenon is called wave-free characteristics. This wave-free characteristics make it possible to design marine structures superior in oscillation performance in waves. Since Bessho`s wave-free theory is useful only for an infinite water depth, this paper studied the wave-free theory for a shallow sea area. On a wave-free singularity and required floating body form, 2-D and 3-D axisymmetric floating body forms were determined, and vertical wave force characteristics of the obtained body forms were calculated and verified experimentally. Since the source term of the wave-free singularity was weaker in a shallow sea area than an infinite deep water area, resulting in the narrow width of the obtained wave-free body forms in a shallow sea area. The wave-free theory for a shallow sea area was verified by both numerical calculation based on a singularity distribution method and model experiment for these floating body forms. 3 refs., 10 figs.

  15. Evaluation for characteristics of around the Nojima fault; Butsuri tansa ni yoru `Nojima jishin danso` shuhen no jiban bussei ni kansuru ichihyoka

    Shimizu, K.; Tsuji, T. [Newjec Inc., Osaka (Japan); Tsuji, M. [OYO Corp., Tokyo (Japan)


    Various surveys were conducted for the area around the Nojima fault, including ground surface, two-dimensional electrical and boring surveys and elastic wave tomography, in order to grasp properties of the ground around the `Nojima earthquake fault.` The resistivity image method as one of the two-dimensional electrical methods was used to grasp fault shapes over a wide range of the 1.6km long section extending between Esaki and Hirabayashi. The courses of traverse were set in the direction almost perpendicular to the fault. Boreholes were excavated and elastic wave tomography was conducted between the boreholes on the 9th and 17th courses of traverse, to confirm ground/mountain conditions and to compare the results with observed elastic wave velocities. Very low resistivities are observed at places where granite is distributed, suggesting that the fault-induced changes are not limited to the area around the fault. The zone in which elastic wave velocity decreases is narrow, 10m at the longest, at a velocity of 2.4km/s or lower, which is a low velocity for that propagating in granite. 5 refs., 4 figs.

  16. 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.

  17. Studies on surface tension effect for free surface flow around floating models; Futai mokei mawari no jiyu hyomenryu ni oyobosu hyomen choryoku no eikyo ni kansuru kenkyu

    Suzuki, K. [Yokohama National Univ., Yokohama (Japan). Faculty of Engineering; Akiba, H. [Toyo Construction Co. Ltd., Tokyo (Japan)


    The effect of surface tension on free surface flow around floating models is discussed experimentally and numerically. Three-dimensional free surface flow around vertical circular cylinders floating in a circulating water channel was visually observed, where a surface-active agent was added to water. The results are analyzed using Weber number. The numerical analysis was done for vertical cylinder and CY100 models using the Rankine source method. Weber number of at least around 120 is necessary to eliminate the effect of surface tension from free surface flow around the CY100 model. The numerical analysis for the cylinder model needs simulation with wavelength shorter than that of free surface wave used by the Rankine source method. The model for the resistance test should be at least around 7m long to eliminate the effect of surface tension at Froude number of 0.1 or higher. 15 refs., 12 figs., 2 tabs.

  18. Stress estimation around the survey wells in Hanshin-Awaji area by means of AE/DR and DSCA experiments; AE/DR ho to DSCA ho ni yoru Hanshin Awaji chiiki chosa kui shuhen no chikaku oryoku sokutei

    Ito, H.; Kuwahara, Y.; Nishizawa, O. [Geological Survey of Japan, Tsukuba (Japan); Yamamoto, K. [Tohoku University, Sendai (Japan). Faculty of Science; Sano, O. [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering; Yokoyama, T.; Kudo, R. [OYO Corp., Tokyo (Japan); Xue, Z. [Kiso-Jiban Consultants Co. Ltd., Tokyo (Japan)


    A total of 5 wells were excavated in the Hanshin-Awaji area (Ikeda, Takarazuka, Tarumi, Hirabayashi and Ikunami) to collect the core samples, which were analyzed by the AE/DR and DSCA methods to determine crustal stresses. For the AE/DR analysis, the core sample was cut in the vertical direction, and in the horizontal direction at intervals of 45{degree}. The sample of unknown orientation was provided with a datum line common for both methods, to compare the results by these methods. A load was applied to the sample, provided with an AE sensor and strain gauge on the sides, in the longitudinal direction. For the DSCA analysis, the core sample was cut into a cube having a side length of 33mm, with a pair of planes directed in parallel to the datum line. A total of 18 strain gauges, 10mm in gauge length, were attached to the cube. The AE/DR analysis gave the maximum and minimum principal stresses in the horizontal plane and stresses in the vertical direction, whereas the DSCA the maximum, intermediate and minimum principal stresses. 3 refs., 7 figs.

  19. Preventive measures against liquefaction in consideration of peripheral environment. Example of SAVE (Silent, Advanced Vibration-Erasing) composer method; Shuhen kankyo ni hairyoshita ekijoka taisaku koho. Seiteki shimekatame sunakui (SAVE composer) koho no sekorei

    Sasaki, K.; Takahashi, Y.; Fukada, H. [Fudo Construction Co. Ltd., Tokyo (Japan)


    This paper presents the working machine, method and example of the newly developed SAVE composer method. The working machine of the SAVE composer method adopts a forced elevating equipment and rotating penetration equipment equipped with an auger motor for hydraulic forced penetration and elevation of a casing. The process of the SAVE composer method is composed of setting a casing at a proper position. charging material from a hopper to a casing, penetrating a casing up to a proper depth by the auger motor of the rotating penetration equipment, discharging material by extracting a casing, and re-penetrating a casing for compaction of discharged material. This method is free from noise and vibration because of no use of an excitor. This method was used for preventive measures against liquefaction at the coastal levee of Tsu-Matsuzaka harbor, Mie prefecture. As a result, nearly the same improvement effect as conventional SCP method, and considerable vibration reduction were confirmed. 3 refs., 12 figs., 1 tab.

  20. 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.

  1. 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.

  2. On the hydroelastic response of box-shaped floating structure with shallow draft. Tank test with large scale model; Senkitsusui hakogata futai no harochu dansei oto ni tsuite. Ogata mokei ni yoru suiso shiken

    Yago, K.; Endo, H. [Ship Research Inst., Tokyo (Japan)


    The hydroelastic response test was carried out in waves using an approximately 10m long large model, and the numerical analysis was done by the direct method, for a commercial-size (300m long) box-shaped floating structure with shallow draft. The scale ratio of the model is 1/30.8, and the minimum wave cycle is around 0.7s from wave-making capacity of the tank, which corresponds to 4 to 14s with the commercial-size structure. Elastic displacement and bending strain were measured. The calculated results by the direct method are in good agreement with the observed results. The fluid dynamic mutual interference effects between elements are weak in added mass but strong in damping force, indicating that the range of mutual interference is strongly related to rolling cycle in the range of mutual interference. Wave pressure on the floating structure bottom is high at the upper side of the wave, greatly damping towards the downside of the wave. However, response amplitude of elastic displacement tends to increase at the ends, both in upside and downside of the wave. For the floating structure studied, the 0 to 4th mode components are predominant in longitudinal waves, and the 6th or higher mode components are negligibly low. 21 refs., 15 figs., 2 tabs.

  3. Investigation on the dynamic response and strength of very long floating structures by beam modeling on an elastic foundation; Dansei shishojo no hari model ni yoru chodai futai kozo no doteki tawami kyodo tokusei ni kansuru kosatsu

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


    A very large floating structure was replaced with the beam on an elastic foundation to examine the response characteristics in waves. Another evidence was regularly and numerically given for the basic characteristics of a very large floating body Suzuki found. New information was also obtained. The frequency response is mainly classified into a wave number control area and proper frequency control area when buoyancy elasticity exists. When the buoyancy structure is long and flexible, the proper frequency becomes continuous and the frequency control area becomes a resonance area. In the wave number control area, the Suzuki`s characteristic wave number becomes a control parameter, and various characteristic values are indicated by characteristic wave numbers. The response in the wave number control area becomes quasi-static when the distribution mass of buoyancy is fully small. The design in which the distribution mass of buoyancy is fully large must be avoided. In the displacement amplitude, the mass on the free end is severest. The proper frequency of vertical vibration relatively moves to the high-frequency side when buoyancy is considered as an elastic foundation. Attention must be thus paid to the proper frequency of vibration on the horizontal surface. 9 refs., 12 figs., 3 tabs.

  4. Diversité floristique sur les cloisonnements de futaies de chêne: est-elle associée à la perturbation, au micro-environnement ou à l'âge du peuplement?

    Wei, L; Villemey, A.; Hulin, F.; Bilger, I.; Dumas, Y.; Chevalier, R.; F. Archaux; Gosselin, F.


    Increasingly mechanized timber harvesting and the repeated use of skid trail networks may affect ground vegetation differently at subsequent stages in the forest rotation. At a fine scale, no studies have yet compared the influence of micro-environmental factors and the effects of skid trail disturbance on ground flora diversity. We investigated understory diversity patterns on skid trails in 30-, 50- and 63-year-old oak forests in the northern half of France. Subplots were placed on skid tra...

  5. Relations morphologie-cycle de l'azote au sein de l'épisolum humifère en futaie régulière pure de hêtre

    Trap, Jean


    L'objectif de cette thèse est de contribuer à la compréhension (i) des relations morphologie/cycle de l'azote au sein de l'épisolum humifère, (ii) du cycle de l'azote au sein des différents horizons de l'épisolum humifère et (iii) des facteurs écologiques responsables du développement des formes d'humus et régulant le cycle de l'azote dans l'épisolum le long d'une chronoséquence de 130 ans en hêtraies pures. Le cycle de l'azote. L'ammonification potentielle nette augmente avec l'âge des peupl...

  6. Fiscal 1999 research and development of technologies for practical application of photovoltaic power generation systems. Research and development of photovoltaic power utilizing system and peripheral technologies (Research and development for enhancing reliability of photovoltaic power generation - Research on long-term reliability of inverter); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Taiyoko hatsuden riyo system shuhen gijutsu no kenkyu kaihatsu (taiyoko hatsuden no shinraisei kojo ni kansuru kenkyu kaihatsu - inverter no choki shinraisei no chosa kenkyu)



    In fiscal 1999, the power conditioner which is the primary component of a photovoltaic power system was subjected to an accelerated test, etc., for the evaluation of its durability. For the accelerated test, operating conditions were so set that acceleration be implemented according to Arrhenius' law at ambient temperature 40 degrees C and relative humidity 36%. For the operation of the power conditioner, it was so set that the operation duration be 3.5 hours with a rest time of 4.5 hours for the night or the like. In the accelerated test conducted as in the previous year, 1100 cycles were completed recording the maximum, equivalent to approximately 8-1/2 years according to Arrhenius' law. After the test, no life affecting changes were detected in specimen device A, B, or D. Specimen C, however, failed during the test. As for the evaluation of durability of components, the electrolytic capacitor in the power conditioner was named. Reliability related literature was investigated and a durability evaluation test was started, with consideration given to the voltage to apply and service temperature. (NEDO)

  7. FY 2000 report on the results of the development of technology for commercialization of the photovoltaic power system - R and D of the photovoltaic power generation utilization system/peripheral technology. R and D of new solar cell modules integrated with construction materials (high durability roof modules); 2000 nendo New sunshine keikaku seika hokokusho. Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu, Taiyoko hatsuden riyo system, Shuhen gijutsu no kenkyu kaihatsu - Shinkenzai ittaigata taiyodenchi mojuru no kenkyu kaihatsu (Kotaikyusei yane mojuru)



    The R and D were conducted of new AC-powered solar cell modules integrated with construction materials for residential use of the large roof panel system, and the FY 2000 results were summarized. In the study of the durable structure of solar cell modules and roof modules, development was made of the roof panel use thin film CdTe solar cell module of a hollow sealing structure and small size/high power system interconnection power conditioner. Further, by the design of PV installation structure and roof panel structure, the performance of construction materials and fire-resistance performance were secured, and the module and power conditioner passed the verification test under the Building Standard Law. At the efficiency of large CdTe thin film solar cell module of 11.0%, the roof array efficiency was 9.2% at roof panel and 8.6% at house roof, and the target efficiency was achieved. Moreover, the initial target of the system expansion cost of 170 yen/W or below was achieved by a combination of the large tireless roof panel assembled in factory, large frameless thin film solar cell module and power conditioner that is AC-powered at roof panel unit. (NEDO)

  8. 地震资料在车古201块储层建模中的应用%Application of Seismic Data to Reservoir Modeling of the Chegu 201 Block

    蔡毅; 张祥忠; 张新赏


    Great uncertainty exists in reservoir models built for blocks where well spacing is uneven or large. The uncertainty in reservoir models can be significantly reduced by using Coordinate Cokriging Sequential Gaussian Simulation technology, in combination with the restriction of seismic characteristic data. Satisfactory reservoir parameter interpolation results, which are more accurate than those derived only from borehole data, are obtained, giving rise to a reasonable combination of widespread and dense-sampled seismic (soft data) data with borehole data (hard data). A significant effect has been made in reservoir parameter modeling in the Chegu 201 block of the Futai Oilfield by using this technology.

  9. Application of Seismic Data to Reservoir Modeling of the Chegu 201 Block

    CaiYi; ZhangXiangzhong; ZhangXinshang


    Great uncertainty exists in reservoir models built for blocks where well spacing is uneven or large. The uncertainty in reservoir models can be significantly reduced by using Coordinate Cokriging Sequential Gaussian Simulation technology, in combination with the restriction of seismic characteristic data. Satisfactory reservoir parameter interpolation results, which are more accurate than those derived only from borehole data, are obtained, giving rise to a reasonable combination of widespread and dense-sampled seismic (soft data) data with borehole data (hard data). A significant effect has been made in reservoir parameter modeling in the Chegu 201 block of the Futai Oilfield by using this technology.

  10. Etude de la croissance et du niveau de production des peuplements résineux en Wallonie

    Perin, Jérôme


    Nos recherches visent à améliorer les connaissances de base en sylviculture et en écologie des essences résineuses dans l’optique d’une gestion forestière à vocation principale de production de bois de qualité. Nos études se focalisent principalement sur les futaies équiennes pures de douglas, d'épicéa et de mélèzes mais il est prévu de les étendre aux peuplements mélangés d'épicéa-douglas. D'un point de vue pratique, cette action de recherche vise, à terme, à proposer différents scénarios...

  11. Le Δ13C des cernes révèle l'impact de la gestion forestière passée sur l'efficience d'utilisation de l'eau dans un taillis de chêne méditerranéen en Toscane (Italie)

    Di Matteo, Giovanni; De Angelis, Paolo; Brugnoli, Enrico; Cherubini, Paolo; Scarascia-Mugnozza, Giuseppe


    * Les effets de l'éclaircie et de la réduction importante de la densité du peuplement ont été étudiés dans des forêts de chêne de Turquie (Quercus cerris L.) de l'Italie centrale, afin d'évaluer les réactions physiologiques et l'état de croissance des arbres qui ont survécu à une coupe de taillis et à une éclaircie pour la conversion du peuplement en futaie.* L'hypothèse de travail était qu'une forte diminution de la densité du peuplement entraînerait une baisse de l'efficience intrinsèque d'...

  12. Influence of tree species on gross and net N transformations in forest soils

    Zeller, Bernhard (Hrsg.); Recous, Sylvie; Kunze, Morgan; Moukoumi, Judicaël; Colin-Belgrand, Micheline; Bienaime, Séverine; Ranger, Jacques; Dambrine, Etienne


    Nous avons mesuré les flux de minéralisation nette d’azote au cours d’une incubation de quatre semaines et les flux bruts d’azote au cours d’une incubation de deux jours dans 6 sols prélevés dans une comparaison d’espèces forestières. Nous avons comparé les horizons A1 d’un taillis sous futaie (TSF) de Fagus sylvatica et de cinq plantations adjacentes de 25 ans de Fagus sylvatica, Picea abies, Quercus petraea, Pinus laricio et Pseudotsuga menziesii. Les taux bruts ont été mesurés 48 h après l...

  13. Lipopolysaccharide-induced multinuclear cells: Increased internalization of polystyrene beads and possible signals for cell fusion

    Nakanishi-Matsui, Mayumi, E-mail:; Yano, Shio; Futai, Masamitsu


    Highlights: •LPS induces multinuclear cells from murine macrophage-derived RAW264.7 cells. •Large beads are internalized by cells actively fusing to become multinuclear. •The multinuclear cell formation is inhibited by anti-inflammatory cytokine, IL10. •Signal transduction for cell fusion is different from that for inflammation. -- Abstract: A murine macrophage-derived line, RAW264.7, becomes multinuclear on stimulation with lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria. These multinuclear cells internalized more polystyrene beads than mononuclear cells or osteoclasts (Nakanishi-Matsui, M., Yano, S., Matsumoto, N., and Futai, M., 2012). In this study, we analyzed the time courses of cell fusion in the presence of large beads. They were internalized into cells actively fusing to become multinuclear. However, the multinuclear cells once formed showed only low phagocytosis activity. These results suggest that formation of the multinuclear cells and bead internalization took place simultaneously. The formation of multinuclear cells was blocked by inhibitors for phosphoinositide 3-kinase, phospholipase C, calcineurin, and c-Jun N-terminal kinase. In addition, interleukin 6 and 10 also exhibited inhibitory effects. These signaling molecules and cytokines may play a crucial role in the LPS-induced multinuclear cell formation.

  14. Roles of the β subunit hinge domain in ATP synthase F1 sector: Hydrophobic network formed by introduced βPhe174 inhibits subunit rotation

    The ATP synthase β subunit hinge domain (βPhe148 ∼ βGly186, P-loop/α-helixB/loop/β-sheet4, Escherichia coli residue numbering) dramatically changes in conformation upon nucleotide binding. We previously reported that F1 with the βSer174 to Phe mutation in the domain lowered the γ subunit rotation speed, and thus decreased the ATPase activity [M. Nakanishi-Matsui, S. Kashiwagi, T. Ubukata, A. Iwamoto-Kihara, Y. Wada, M. Futai, Rotational catalysis of Escherichia coli ATP synthase F1 sector. Stochastic fluctuation and a key domain of the β subunit, J. Biol. Chem. 282 (2007) 20698-20704.]. Homology modeling indicates that the amino acid replacement induces a hydrophobic network, in which the βMet159, βIle163, and βAla167 residues of the β subunit are involved together with the mutant βPhe174. The network is expected to stabilize the conformation of βDP (nucleotide-bound form of the β subunit), resulting in increased activation energy for transition to βE (empty β subunit). The modeling further predicts that replacement of βMet159 with Ala or Ile weakens the hydrophobic network. As expected, these two mutations experimentally suppressed the ATPase activities as well as subunit rotation of βS174F. Furthermore, the rotation rate decreased with the increase of the strength in the hydrophobic network. These results indicate that the smooth conformational change of the β subunit hinge domain is pertinent for the rotational catalysis.

  15. Effects of mutations in the β subunit hinge domain on ATP synthase F1 sector rotation: Interaction between Ser 174 and Ile 163

    A complex of γ, ε, and c subunits rotates in ATP synthase (FoF1) coupling with proton transport. Replacement of βSer174 by Phe in β-sheet4 of the β subunit (βS174F) caused slow γ subunit revolution of the F1 sector, consistent with the decreased ATPase activity [M. Nakanishi-Matsui, S. Kashiwagi, T. Ubukata, A. Iwamoto-Kihara, Y. Wada, M. Futai, Rotational catalysis of Escherichia coli ATP synthase F1 sector. Stochastic fluctuation and a key domain of the β subunit, J. Biol. Chem. 282 (2007) 20698-20704]. Modeling of the domain including β-sheet4 and α-helixB predicted that the mutant βPhe174 residue undergoes strong and weak hydrophobic interactions with βIle163 and βIle166, respectively. Supporting this prediction, the replacement of βIle163 in α-helixB by Ala partially suppressed the βS174F mutation: in the double mutant, the revolution speed and ATPase activity recovered to about half of the levels in the wild-type. Replacement of βIle166 by Ala lowered the revolution speed and ATPase activity to the same levels as in βS174F. Consistent with the weak hydrophobic interaction, βIle166 to Ala mutation did not suppress βS174F. Importance of the hinge domain [phosphate-binding loop (P-loop)/α-helixB/loop/β-sheet4, βPhe148-βGly186] as to driving rotational catalysis is discussed

  16. Lipopolysaccharide induces multinuclear cell from RAW264.7 line with increased phagocytosis activity

    Nakanishi-Matsui, Mayumi, E-mail: [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Futai Special Laboratory, Yahaba, Iwate 028-3694 (Japan); Yano, Shio; Matsumoto, Naomi; Futai, Masamitsu [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Futai Special Laboratory, Yahaba, Iwate 028-3694 (Japan)


    Highlights: Black-Right-Pointing-Pointer LPS induces multinuclear cells from murine macrophage-derived RAW264.7 cells. Black-Right-Pointing-Pointer The multinuclear cells are formed through cell-cell fusion in the presence of Ca{sup 2+}. Black-Right-Pointing-Pointer The multinuclear cells do not express osteoclast-specific enzymes. Black-Right-Pointing-Pointer They internalized more and larger beads than mononuclear cells and osteoclasts. -- Abstract: Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria, induces strong proinflammatory responses, including the release of cytokines and nitric oxide from macrophage. In this study, we found that a murine macrophage-derived line, RAW264.7, became multinuclear through cell-cell fusion after incubation with highly purified LPS or synthetic lipid A in the presence of Ca{sup 2+}. The same cell line is known to differentiate into multinuclear osteoclast, which expresses a specific proton pumping ATPase together with osteoclast markers on stimulation by the extracellular domain of receptor activator of nuclear factor {kappa}B ligand (Toyomura, T., Murata, Y., Yamamoto, A., Oka, T., Sun-Wada, G.-H., Wada, Y. and Futai, M., 2003). The LPS-induced multinuclear cells did not express osteoclast-specific enzymes including tartrate-resistant acid phosphatase and cathepsin K. During multinuclear cell formation, the cells internalized more and larger polystyrene beads (diameter 6-15 {mu}m) than mononuclear cells and osteoclasts. The internalized beads were located in lysosome-marker positive organelles, which were probably phagolysosomes. The LPS-induced multinuclear cell could be a good model system to study phagocytosis of large foreign bodies.