Sample records for capsizing

  1. Capsizing icebergs release earthquake-sized energies (United States)

    Schultz, Colin


    A large iceberg can carry a tremendous amount of gravitational potential energy. While all icebergs float with the bulk of their mass submerged beneath the water's surface, some drift around in precarious orientations—they are temporarily stable, but an outside push would send them tumbling over. Large icebergs, like those that split from the Jakobshavn Isbræ glacier in Greenland, can release the energy equivalent to a magnitude 6 or 7 earthquake when they capsize. A 1995 event demonstrated the potential for destruction, as a tsunami spawned from a capsizing iceberg devastated a coastal Greenland community. Measuring how energy is dispersed during capsizing is crucial to understanding the risk associated with these events but is also key to determining their larger role in surface ocean dynamics


    Directory of Open Access Journals (Sweden)

    De-wei Pan


    Full Text Available The processes of marine salvage require firstly the uprighting of the capsized ship, essentially bringing the deck to point up. Analysis and computation are the keys for the success in the application of the design schemes. Up to date, there are few researches on calculation methods for uprighting process of capsized ships at China and abroad. Researches about the effect of flooding quantity and the variation of the longitudinal strength during the uprighting process of capsized and damaged ships are even rarer. In this paper, hydromechanical equations to describe the effect of flooding are established and a calculation method for the longitudinal strength is introduced with reference to the hydrostatic theory for ships. Three typical uprighting processes are summarized according to the methods of treatment of damaged compartment. The stability of the inverted ship is calculated and analyzed using the General Hydrostatics software(GHS. Reserve buoyancy, shear forces, bending moments and torques are calculated in nine positions along the ship.

  3. Iceberg capsize hydrodynamics: a comparison of laboratory experiments and numerical modeling (United States)

    Burton, J. C.; Cathles, L. M.; Correa-Legisos, S.; Ellowitz, J.; Darnell, K.; Zhang, W. W.; MacAyeal, D. R.


    Large icebergs are often observed to capsize in open water near fjords. During capsize, large amounts of gravitational potential energy are released which can lead to coastal tsunamis, mixing of the water column, and possibly lead to further calving at the glacier terminus. This process is rarely studied; in nature the scale and irregular timing of the events makes observations exceedingly difficult. Here we compare laboratory experiments and numerical modeling of the capsize process to better understand the coupling of the hydrodynamic forces to the solid iceberg. Although the characteristic Reynolds number is much lower for both the laboratory model and the numerical simulations, the comparison provides a starting point to quantify and identify generic features that can be estimated in the field, such as hydrodynamic pressure, water flow velocities, vertical mixing, and elastic stresses on the iceberg itself, which could lead to fracture.

  4. Global Geometric Analysis of Ship Rolling and Capsizing in Random Waves

    Institute of Scientific and Technical Information of China (English)


    The nonlinear biased ship rolling motion and capsizing in random waves are studied by utilizing a global geometric method. Thompson's α-parameterized family of restoring functions is adopted in the vessel equation of motion for the representation of bias. To take into account the presence of randomness in the excitation and the response, a stochastic Melnikov method is developed and a mean-square criterion is obtained to provide an upper bound on the domain of the potential chaotic rolling motion. This criterion can be used to predict the qualitative nature of the invariant manifolds which represent the boundary between safe and unsafe initial conditions, and how these depend on system parameters of the specific ship model. Phase space transport theory and lobe dynamics are used to demonstrate how motions starting from initial conditions inside the regions bounded by the intersected manifolds will evolve and how unexpected capsizing can occur.

  5. Exploration of ocean waves created by iceberg calving and capsize using SPH (smoothed particle hydrodynamics) (United States)

    Macayeal, D. R.


    The interaction between icebergs, their parent ice shelves and the fluid in which they float (seawater) is one of the most demanding problems in glaciology because the interactions involve multiple widely divergent time scales, a variety of constitutive behaviors along with free surfaces and disconnected domains. As calving begins, compressibility and surface tension of seawater comes into play as free-falling ice encounters the ocean surface, producing jets of spray and filling the water with plumes of bubbles. As calving proceeds, incompressible hydrodynamics describes the interaction between the iceberg and the surface waves (tsunamis) the calving event creates in the ocean. In regions where the Froude number (which inversely measures the ability of the water to relieve pressure on the iceberg, ice shelf and seabed by radiating free-surface gravity waves) is greater than 1, hydraulic pressure coupling can produce extraordinary tensile and compressive stresses in the iceberg and ice shelf, triggering further calving. Eventually, a hydrostatic pressure regime develops in which icebergs may further evolve through capsize, which often produces such strong elastic stress within the iceberg sufficient to cause its disintegration. This presentation will focus on the use of SPH as a means of modeling ice/ocean interaction during iceberg calving. Goals of the investigation will be methodological and will evaluate the efficiency and accuracy of the computation of boundary forces which act on icebergs, ice shelves and seabed/fjord walls during iceberg calving and capsize.

  6. Analytical method of capsizing probability in the time domain for ships in the random beam seas

    Institute of Scientific and Technical Information of China (English)

    LIU Liqin; TANG Yougang; LI Hongxia


    The methods for constructing safe basins of ships and predicting their survival probability in random waves were studied.The nonlinear differential equation of the rolling motion of ships in random beam seas was established considering nonlinear damping,nonlinear restoring moment,and random waves.The random rolling differential equation was solved in the time domain by applying the harmonic acceleration method and by synthetically considering the instantaneous state of ships and the narrowband wave energy spectrum.The numerical simulation of random capsizing course was brought forward,the safe basins were constructed for safe navigation,and the survival probabilities of ships were calculated.As an example,the safe basins on the rolling initial value plane were constructed for a 30.27-meter-long fishing vessel according to different initial conditions and random wave parameters.The survival probabilities of the fishing vessel under different significant wave heights were predicted.Thus,the survival probabilities of ships in random seas can be predicted quantitatively by the proposed method.

  7. Model experiment on capsizing of damaged RO-RO passenger ship in beam seas; Sonsho shita RO-RO kyakusen no ohachu tenpuku ni kansuru mokei jikken

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, T.; Ishida, S. [Ministry of Transportation, Tokyo (Japan)] Murashige, S. [Tokyo Univ. (Japan)


    In this study, a model of the RO-RO passenger ship was made, a capsizing experiment was carried out in a case of a damaged crack existed in higher wave height side in the beam seas. The main results were obtained as follows: the restored standard after damage was satisfied in the Treaty of Safety of Life at Sea (SOLAS`90) and the capsizing would not happen in the case of no initial heel. In the case with initial heel, ship would be heeled to the side of higher wave height with damage crack, capsizing would happen when the significant wave height was higher and the permeability to the car deck was larger. That is, it was necessary for residence water to easily stay in the damage side with the initial heel in order that the capsizing happened. In the case of the capsizing with an initial heel, the critical height of the residence water on the car deck was nearly in agreement with the British proposal: `calculation equations showing necessary restored performance in consideration of the permeation to the car deck`, when the peak period in wave spectrum was 7 to 9 seconds. There is no agreement when the peak period is longer than that. 11 refs., 15 figs., 4 tabs.

  8. CAPSIZE: A personal computer program and cross-section library for determining the shielding requirements, size, and capacity of shipping casks subject to various proposed objectives

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.


    A new interactive program called CAPSIZE has been written for the IBM-PC to rapidly determine the likely impact that proposed design objectives might have on the size and capacity of spent fuel shipping casks designed to meet those objectives. Given the burnup of the spent fuel, its cooling time, the thickness of the internal basket walls, the desired external dose rate, and the nominal weight limit of the loaded cask, the CAPSIZE program will determine the maximum number of PWR fuel assemblies that may be shipped in a lead-, steel-, or uranium-shielded cask meeting those objectives. The necessary neutron and gamma shield thicknesses are determined by the program in such a way as to meet the specified external dose rate while simultaneously minimizing the overall weight of the loaded cask. The one-group cross-section library used in the CAPSIZE program has been distilled from the intermediate results of several hundred 1-D multigroaup discrete ordinates calculations for different types of casks. Neutron and gamma source terms, as well as the decay heat terms, are based on ORIGEN-S analyses of PWR fuel assemblies having exposures of 10, 20, 30, 40, 50, and 60 gigawatt days per metric tonne of initial heavy metal (GWD/MTIHM). In each case, values have been tabulated at 17 different decay times between 120 days and 25 years. Other features of the CAPSIZE program include a steady-state heat transfer calculation which will minimize the size and weight of external cooling fins, if and when such fins are required. Comparisons with previously reported results show that the CAPSIZE program can generally estimate the necessary neutron and gamma shield thicknesses to within 0.16 in. and 0.08 in., respectively. The corresponding cask weights have generally been found to be within 1000 lbs of previously reported results. 13 refs., 20 figs., 54 tabs.

  9. How to Make Waves without Capsizing Your Superintendency. (United States)

    Berger, Stuart


    Recounts one superintendent's reorganization of his top-management team to comprise fewer members and achieve better racial and gender balance. Presents administrator selection principles, such as choosing only people sharing the superintendent's educational values, looking for competence in different packages, and selecting a majority of team…

  10. Survey and Multi-Scale Characteristics of Wind Damage Caused by Convective Storms in the Surrounding Area of the Capsizing Accident of Cruise Ship “Dongfangzhixing”%“东方之星”客轮翻沉事件周边区域风灾现场调查与多尺度特征分析

    Institute of Scientific and Technical Information of China (English)

    郑永光; 田付友; 孟智勇; 薛明; 姚聃; 白兰强; 周晓霞; 毛旭; 王明筠


    The extraordinarily serious capsizing accident of the cruise ship,named Dongfangzhixing (Eastern Star),occurred at around 21:30 BT 1 June 2015,in the Jianli (Hubei Province)section of the Yangtze River. Based on the results of the wind damage survey with satellite and radar data analyses,this paper presents that the high wind damage was caused by downbursts and one likely tornado over the area surrounding the event occurring site at around 21:00-21:40 BT 1 June,with the most intense Beaufort scale more than level 12,and the characteristics of discontinuous and multiscale spatial distribution and very small spatio-temporal scale of the most severe wind damage.The wind damage over the northern land part of the surrounding area (Shunxingcun,Laotai Deep Water Wharf,Sitaicun,Xingouzi)affected by one mesocyclone is more signifi-cant than the southern land part behind the gust front and microbursts.It is determined that one likely tor-nado occurred at Laotai Deep Water Wharf,and the wind damage at other sites was caused by microbursts based on the radar data and damage survey.The flows in the convective storm causing wind damage have obvious multiscale characteristics,and a number of microburst swathes simultaneously occurred at the woods of Sitaicun located in the northern part of the surrounding area,with alternate spatial distribution of divergence and convergence,displaying a feature of the complicated atmospheric motion in the convective storm.Although mesovortices occur within a microburst,the horizontal scale of convergence within the microburst found in this wind damage survey was only tens of meters and far less than the several-kilome-ter horizontal scale of bookend vortices or mesovortices within a bow echo.%提2015年6月1日21:30左右长江湖北监利段发生“东方之星”客轮翻沉特大事故。本文根据事发周边陆地区域现场天气调查结果,结合卫星和雷达观测资料分析认为,6月1日21:00—21:40左右事发江

  11. Nonlinear Time-Domain Simulation of Ship Capsizing in Beam Seas. (United States)


    1991; Lin & Yue, 1990; Bingham, et al., 1993) or the Rankine source methods (eg, Nakos & Sclavounos, 1990). Linear methods have been very successful...A.E. (1981), "Users Manual for the Standard Ship Motion Program, SMP," DTNSRDC Report SPD-0936-01. Nakos , D.E. and Sclavounos, P.D. (1990), Ship...1991), Lin k Yue (1990), Bingham, et al, (1993)) or the Rank- ine source methods (e.g., Nakos k Sclavounos (1990)). Linear frequency-domain methods

  12. Finite element analysis of effects of pile cap'sizes to pile's lateral capacity%承台大小对桩水平承载力影响的有限元分析

    Institute of Scientific and Technical Information of China (English)

    王继成; 柳爱



  13. 33 CFR 62.65 - Procedure for reporting defects and discrepancies. (United States)


    ... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the... missing, sunk, capsized, damaged, off station, or showing characteristics other than those advertised...


    Institute of Scientific and Technical Information of China (English)

    HU YUE


    @@ TO THE POINT: Chinese fund management companies spilled red ink in the first half of 2010 as the stock market turned bearish. The shipbuilding industry regains its lost ground but unsteady seas could capsize hopes for continued success.

  15. A Dynamic Model for Roll Motion of Ships due to Flooding

    DEFF Research Database (Denmark)

    Xia, Jinzhu; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup


    Because of the large undivided deck spaces, RoRo vessels are often sensitive to rapid capsizing due to sudden ingress of water. Following a high-energy damage, a rapidly increasing heeling moment is induced by the ingress of water, which generates a roll motion of the damaged vessel. If, addition...

  16. Powering and Motion Predictions of High Speed Sea Lift (HSSL) Ships (United States)


    course are studied. and heading PID controllers for a destroyer configuration. b. Capsize/broaching: effect of control and The destroyer, represented...maximum values and maximum rates of change. A and a maximum allowed rudder rate. PID controllers use Hough and Ordway body force model is used to

  17. Mustering and evacuation of passengers : scientific basis for design

    NARCIS (Netherlands)

    Boer, L.C.


    The capsizing of the HERALD in 1987 (death toll 193) and the ESTONIA in 1994 (death toll 852) have shown that safety can be tenibly insufficient. That is why, since these disasters, moves to improve safety on board ship have gathered momentum. And this had led to the authorities paying special atten

  18. 14 CFR 29.755 - Hull buoyancy. (United States)


    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.755 Hull buoyancy. Water-based and amphibian rotorcraft. The hull and auxiliary floats, if used, must have enough... stability great enough to minimize the probability of capsizing the rotorcraft for the worst combination...

  19. The dynamic behaviour of man-wide vehicles with an automatic active tilting mechanism

    NARCIS (Netherlands)

    Pauwelussen, J.P.


    The major advantage of a motorcycle with respect to a passenger car is the possibility of the driver to tilt during cornering and thereby maintaining stability whereas a passenger car will suffer from the risk of capsizing at high speed. This observation has lead Brink Dynamics to create and develop

  20. The dynamic performance of narrow actively tilting vehicles

    NARCIS (Netherlands)

    Pauwelussen, J.P.


    The major advantage of a motorcycle with respect to a passenger car is the possibility of the driver to tilt during cornering and thereby maintaining stability whereas a passenger car will suffer from the risk of capsizing at high speed. This observation has motivated recently various manufacturers

  1. Fuzzy Reasoning as a Base for Collision Avoidance Decision Support System


    tanja brcko; jelenko švetak


    Despite the generally high qualifications of seafarers, many maritime accidents are caused by human error; such accidents include capsizing, collision, and fire, and often result in pollution. Enough concern has been generated that researchers around the world have developed the study of the human factor into an independent scientific discipline. A great deal of progress has been made, particularly in the area of artificial intelligence. But since total autonomy is not yet expedient, the deci...

  2. A laboratory scale model of abrupt ice-shelf disintegration (United States)

    Macayeal, D. R.; Boghosian, A.; Styron, D. D.; Burton, J. C.; Amundson, J. M.; Cathles, L. M.; Abbot, D. S.


    An important mode of Earth’s disappearing cryosphere is the abrupt disintegration of ice shelves along the Peninsula of Antarctica. This disintegration process may be triggered by climate change, however the work needed to produce the spectacular, explosive results witnessed with the Larsen B and Wilkins ice-shelf events of the last decade comes from the large potential energy release associated with iceberg capsize and fragmentation. To gain further insight into the underlying exchanges of energy involved in massed iceberg movements, we have constructed a laboratory-scale model designed to explore the physical and hydrodynamic interactions between icebergs in a confined channel of water. The experimental apparatus consists of a 2-meter water tank that is 30 cm wide. Within the tank, we introduce fresh water and approximately 20-100 rectangular plastic ‘icebergs’ having the appropriate density contrast with water to mimic ice. The blocks are initially deployed in a tight pack, with all blocks arranged in a manner to represent the initial state of an integrated ice shelf or ice tongue. The system is allowed to evolve through time under the driving forces associated with iceberg hydrodynamics. Digitized videography is used to quantify how the system of plastic icebergs evolves between states of quiescence to states of mobilization. Initial experiments show that, after a single ‘agitator’ iceberg begins to capsize, an ‘avalanche’ of capsizing icebergs ensues which drives horizontal expansion of the massed icebergs across the water surface, and which stimulates other icebergs to capsize. A surprise initially evident in the experiments is the fact that the kinetic energy of the expanding mass of icebergs is only a small fraction of the net potential energy released by the rearrangement of mass via capsize. Approximately 85 - 90 % of the energy released by the system goes into water motion modes, including a pervasive, easily observed seich mode of the tank


    Institute of Scientific and Technical Information of China (English)


    Chinese fund management companies spilled red ink in the first half of 2010 as the stock market turned bearish. The shipbuilding industry regains its lost ground but unsteady seas could capsize hopes for continued success. Chinese property developers’ financing woes are inten- sifying. China Mobile reported modest growth in first-half profits as compe- tition heats up among the telecom giants. Outbound M&A deals, especially those involving natural resources, by Chinese companies in the first half of this year hit a record high. China aims to lift its installed hydropower capac- ity to 300 million kilowatts by 2015 from the current 200 million kilowatts.

  4. Life raft stabilizer (United States)

    Radnofsky, M. I.; Barnett, J. H., Jr.; Harrison, F. L.; Marak, R. J. (Inventor)


    An improved life raft stabilizer for reducing rocking and substantially precluding capsizing is discussed. The stabilizer may be removably attached to the raft and is defined by flexible side walls which extend a considerable depth downwardly to one another in the water. The side walls, in conjunction with the floor of the raft, form a ballast enclosure. A weight is placed in the bottom of the enclosure and water port means are provided in the walls. Placement of the stabilizer in the water allows the weighted bottom to sink, producing submerged deployment thereof and permitting water to enter the enclosure through the port means, thus forming a ballast for the raft.

  5. Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland (United States)

    Walter, Fabian; Amundson, Jason M.; O'Neel, Shad; Truffer, Martin; Fahnestock, Mark; Fricker, Helen A.


    We investigated seismic signals generated during a large-scale, multiple iceberg calving event that occurred at Jakobshavn Isbræ, Greenland, on 21 August 2009. The event was recorded by a high-rate time-lapse camera and five broadband seismic stations located within a few hundred kilometers of the terminus. During the event two full-glacier-thickness icebergs calved from the grounded (or nearly grounded) terminus and immediately capsized; the second iceberg to calve was two to three times smaller than the first. The individual calving and capsize events were well-correlated with the radiation of low-frequency seismic signals (forces acting at the glacier terminus. The signals therefore appear to be local manifestations of glacial earthquakes, although the magnitudes of the signals (twice-time integrated force histories) were considerably smaller than previously reported glacial earthquakes. We thus speculate that such earthquakes may be a common, if not pervasive, feature of all full-glacier-thickness calving events from grounded termini. Finally, a key result from our study is that waveform inversions performed on low-frequency, calving-generated seismic signals may have only limited ability to quantitatively estimate mass losses from calving. In particular, the choice of source time function has little impact on the inversion but dramatically changes the earthquake magnitude. Accordingly, in our analysis, it is unclear whether the smaller or larger of the two calving icebergs generated a larger seismic signal.

  6. The Applicability of Hydrofoils as a Ship Control Device

    Institute of Scientific and Technical Information of China (English)

    Md. Shamim Mahmud


    Centrifugal forces are commonly created when ships turn, which may cause a ship to capsize in a critical situation. A mathematical model has been developed to optimize the stability coefficients for ship, with the aim to prevent capsizing and to increase ship maneuverability in high-speed water craft. This model can be used to develop algorithms for control system improvement. The mathematical model presented in this paper optimized the use of multipurpose hydrofoils to reduce heeling and the trimming moment, maintaining an upright ship’s position and lessening the resistance via transverse force. Conventionally, the trimming and heeling of a ship are controlled using ballast water;however, under variable sea conditions it is sometimes difficult to control a ship’s motion using ballast water. In this case, a hydrofoil would be more stable and maneuverable than a ballast tank controlled vessel. A movable hydrofoil could theoretically be adapted from moveable aerofoil technology. This study proves the merit of further investigation into this possibility.

  7. An Evidential Reasoning-Based CREAM to Human Reliability Analysis in Maritime Accident Process. (United States)

    Wu, Bing; Yan, Xinping; Wang, Yang; Soares, C Guedes


    This article proposes a modified cognitive reliability and error analysis method (CREAM) for estimating the human error probability in the maritime accident process on the basis of an evidential reasoning approach. This modified CREAM is developed to precisely quantify the linguistic variables of the common performance conditions and to overcome the problem of ignoring the uncertainty caused by incomplete information in the existing CREAM models. Moreover, this article views maritime accident development from the sequential perspective, where a scenario- and barrier-based framework is proposed to describe the maritime accident process. This evidential reasoning-based CREAM approach together with the proposed accident development framework are applied to human reliability analysis of a ship capsizing accident. It will facilitate subjective human reliability analysis in different engineering systems where uncertainty exists in practice.

  8. Fuzzy Reasoning as a Base for Collision Avoidance Decision Support System

    Directory of Open Access Journals (Sweden)

    tanja brcko


    Full Text Available Despite the generally high qualifications of seafarers, many maritime accidents are caused by human error; such accidents include capsizing, collision, and fire, and often result in pollution. Enough concern has been generated that researchers around the world have developed the study of the human factor into an independent scientific discipline. A great deal of progress has been made, particularly in the area of artificial intelligence. But since total autonomy is not yet expedient, the decision support systems based on soft computing are proposed to support human navigators and VTS operators in times of crisis as well as during the execution of everyday tasks as a means of reducing risk levels.This paper considers a decision support system based on fuzzy logic integrated into an existing bridge collision avoidance system. The main goal is to determine the appropriate course of avoidance, using fuzzy reasoning.

  9. Safe Maritime Autonomous Path Planning in a High Sea State (United States)

    Ono, Masahiro; Quadrelli, Marco; Huntsberger, Terrance L.


    This paper presents a path planning method for sea surface vehicles that prevents capsizing and bow-diving in a high sea-state. A key idea is to use response amplitude operators (RAOs) or, in control terminology, the transfer functions from a sea state to a vessel's motion, in order to find a set of speeds and headings that results in excessive pitch and roll oscillations. This information is translated to arithmetic constraints on the ship's velocity, which are passed to a model predictive control (MPC)-based path planner to find a safe and optimal path that achieves specified goals. An obstacle avoidance capability is also added to the path planner. The proposed method is demonstrated by simulations.

  10. Why does Bogota not have at least one metro line? And the reasons why it will probably not have one

    Directory of Open Access Journals (Sweden)

    Óscar A. Alfonso Roa


    Full Text Available Although the decision on the first metro line in Bogotá was first sketched out 75 years ago, the city still does not have it, but there is no academic reflection on the reasons for such delay. During this period, the physical and institutional capital dedicated to mobility has deteriorated to the point of capsizing the system of mass passenger transport. The result is visible in the substantial increase in unproductive travel time, traffic congestion, saturation of the fleet intended for collective mobility and personal insecurity to which users are exposed. This article supports the idea that in a metropolis of eight million people, with powerful infrastructure inflexibility, the layout of the priority metro line should be resolved in favor of connecting the most densely populated areas of the city, which would progressively solve investment lags and would provide increased ecological and financial sustainability of the system of mass transit.

  11. Reliability Analysis of Dynamic Stability in Waves

    DEFF Research Database (Denmark)

    Søborg, Anders Veldt


    exhibit sufficient characteristics with respect to slope at zero heel (GM value), maximum leverarm, positive range of stability and area below the leverarm curve. The rule-based requirements to calm water leverarm curves are entirely based on experience obtained from vessels in operation and recorded......-4 per ship year such brute force Monte-Carlo simulations are not always feasible due to the required computational resources. Previous studies of dynamic stability of ships in waves typically focused on the capsizing event. In this study the objective is to establish a procedure that can identify...... the distribution of the exceedance probability may be established by an estimation of the out-crossing rate of the "safe set" defined by the utility function. This out-crossing rate will be established using the so-called Madsen's Formula. A bi-product of this analysis is a set of short wave time series...

  12. The utilization of natural gas in the electricity production through fuel cell; A utilizacao do gas natural na geracao distribuida atraves de celulas combustiveis

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi Junior, Paulo


    In function of the necessity of electric energy as input of vital importance for the development of the country, this work aims at to offer plus an energy alternative for Brazil. The exploitation of the natural gas reserves recently discovered can be made through modern methods that give as priority the distributed generation and the low ambient impact. All these aspects can be gotten with the use of fuel cell, working with the remodelled natural gas. Increased to the factor of a low ambient impact in the proper generation, the project suggests that the generating source can be located next the consumer, diminishing still more the problems generated for transmission lines, fuel transport, etc. The fuel cell has received a great attention in the international community and some models, some already in commercial period of training, they have shown excellent possibilities of capsize to be one of the future technologies in the generation of electric energy with low ambient impact. (author)

  13. Nonlinear Container Ship Model for the Study of Parametric Roll Resonance

    DEFF Research Database (Denmark)

    Holden, Christian; Galeazzi, Roberto; Rodríguez, Claudio


    Parametric roll is a critical phenomenon for ships, whose onset may cause roll oscillations up to 40, leading to very dangerous situations and possibly capsizing. Container ships have been shown to be particularly prone to parametric roll resonance when they are sailing in moderate to heavy head...... seas. A Matlab/Simulinkr parametric roll benchmark model for a large container ship has been implemented and validated against a wide set of experimental data. The model is a part of a Matlab/Simulink Toolbox (MSS, 2007). The benchmark implements a 3rd-order nonlinear model where the dynamics of roll...... is strongly coupled with the heave and pitch dynamics. The implemented model has shown good accuracy in predicting the container ship motions, both in the vertical plane and in the transversal one. Parametric roll has been reproduced for all the data sets in which it happened, and the model provides realistic...

  14. Properties of type IV plaster considering variation in the mold/model position during setting stage

    Directory of Open Access Journals (Sweden)

    Tarcisio José de Arruda Paes Junior


    Full Text Available Objective: To assess the influence of the position of the mold during the setting stage of type IV stone plaster Durone (Dentsply Ind. Com., Rio de Janeiro, Brazil, on the following properties: surface hardness and roughness. Methods: For the roughness test, two groups (n=6 in the form of pellets were prepared. In the first group, the surface of the base of the device was turned down during the plaster setting stage (N, in the second group this position was inverted, which has been described as an act of capsize it (E. For analysis, a roughness meter with reading precision of 0.01 μm was used. With regard to the hardness analysis, two groups with conical-shaped samples were obtained. The plasters were left to set under the same conditions of the mold/model position described for the previous experiment. Hardness measurement was performed in a durometer with a spherical penetrating tip for Rockwell readout. Three measurements were performed for each test specimen in both tests. Results: The hardness (N - 39.8, standard deviation = 3.3, E - 30.8, standard deviation = 5.6 and roughness data (N - 0.67, standard deviation = 0.17, E - 0.74, standard deviation = 0.13 submitted to the Student’s-t test (5% showed no statistically significant differences for the roughness test (0.489, but showed statistically significant differences for the hardness test (0.014. Conclusion: The variation in the mold/model position influenced the final characteristics of the specimens in terms of hardness, since those obtained with the capsize technique showed lower surface hardness, whereas for roughness these differences were not statistically significant.

  15. Sottotitolazione intralinguistica e inglese ‘lingua franca’: strategie di mediazione audiovisiva

    Directory of Open Access Journals (Sweden)

    Pietro Luigi Iaia


    Full Text Available Abstract – This chapter illustrates the results of a workshop held at the University of Salento, during an English-Italian Translation Course. A group of undergraduate students was asked to produce an intralingual translation for the subtitles of the video Capsized in Lampedusa – Fortress Italia, which deals with the situation in Lampedusa after a boat capsized in October 2013. The original video – available on YouTube – is subtitled into English for Vice News and, in a ‘role play’ exercise (Rosnow 1990, students were commissioned to adopt a type of English that could be directed at a wider international audience also including non-native English speakers. The contrastive analysis of the original and reformulated versions is designed to enquire into the influence and actualisation of the commissioner’s requests in the lexical, structural and functional features of target texts. The extent will also be explored, to which the type of English adopted in the alternative subtitles can be defined as a lingua-franca variation (Seidlhofer 2011, due to the inclusion of specific verb tenses and the selection of simplified syntactic structures (Seidlhofer 2004, aimed at facilitating the audience’s reception and accessibility to the semantic dimensions of the text. Finally, the analysis will also highlight the translators’ attempts to respect the temporal and spatial constraints of subtitles (Neves 2009, as well as the multimodal construction (Kress and van Leeuwen 2006 of audiovisual texts, which result in the use of condensation strategies (Gottlieb 2005; Pedersen 2011, thus proposing the new definition of audiovisual mediation.

  16. Reverse glacier motion during iceberg calving and the cause of glacial earthquakes (United States)

    Murray, T.; Nettles, M.; Selmes, N.; Cathles, M.; Burton, J. C.; James, T.; Edwards, S.; Martin, I.; O'Farrell, T.; Aspey, R. A.; Rutt, I. C.; Bauge, T.


    About half Greenland's mass loss results from iceberg calving, but the physical mechanisms of calving are poorly known and in situobservations are sparse. Glacial earthquakes, globally detectable seismic events, are associated with calving and are occurring at increasing numbers of outlet glaciers in Greenland and Antarctica. However, the processes causing them have not been clear. We installed a wireless network of on-ice GPS sensors at the calving margin of Helheim Glacier for 55 days during summer 2013. The glacier is a major SE Greenland tidewater outlet and during our observations retreated ~1.5 km in a series of calving events. Our GPS sensors captured glacier motion with cm-level accuracy at locations very close to the calving front with a high temporal sampling rate. Calving causes a minutes-long reversal of the glacier's horizontal flow and a downward deflection of its terminus seen on multiple GPS sensors. Each major calving event is associated with a glacial earthquake. For example, a glacial earthquake / calving event on day 206 produced an iceberg of volume 0.36 km3and aspect ratio 0.23. A GPS sensor close to the front showed a pre-earthquake speed of 29 m/day. Immediately prior to the earthquake centroid time, the sensor reversed its direction and moved upglacier at ~40 m/day and downward 10 cm. The reversed motion was sustained for ~200 s and was followed by downglacier rebound and upward movement. The reverse motion of the glacier results from the horizontal force caused by iceberg capsize and acceleration away from the front. We use analog laboratory experiments to demonstrate that the downward motion results from hydrodynamic pressure drop behind the capsizing berg, which also causes an upward force on the solid Earth. We show that these horizontal and vertical forces are the source of glacial earthquakes. Proper interpretation of the earthquake events should allow remote sensing of calving processes at the margins of Greenland and Antarctic


    CERN Multimedia



    INTERNAL RAGATTE - BEST EVER ! If you missed Internal Regatta III on Sunday 11 July, you missed one of the best we can recall! The winds were about perfect, fairly stable Bf 2 with periodic gusts higher and the resulting capsizes to keep crews concentrating. It was extremely hot but we ran the usual three heats for keelboats and a record four for dinghies, catamarans - where there was another record, surely: a total of 11 boats in that class, of which three privately owned by members. And a final record: we calculate five boats were competing in their first-ever regatta. Results on the webpage. Surprisingly for those who remember regattas of a couple of years back, only three keelboats competed, so there would have been plenty of scope for less experienced members to come along regardless and probably find themselves a place. It is also noteworthy that the keelboat winner was Andrea Messina with an - ummm, may I say - less experienced crew himself! We hope this win bodes well for his forthcoming Transl&am...


    CERN Multimedia



    The Dinghy weekend A recent full weekend was run for dinghies: thanks to dedicated help from regular dinghy sailors and teachers, a lot of people overcame their uncertainty or lack of knowledge about dinghies, getting wet, what the gennaker actually does (and why it’s different from a spinnaker), and had good fun. Our trusty Surveillance boat put in a lot of hours (and petrol!) ensuring no-one came to any harm, thanks Christian (pictured) and Rob. It has to be admitted, winds were not, errr, challenging, for most of that weekend: we old salts know that as soon as the weather gets hot, winds abandon us until the autumn. That is a slight exaggeration but remains fact-based - like the old chestnut that if Mont Blanc is wearing a hat of clouds, it’ll rain soon! It was still wet-suit weather, for safety and because voluntary capsizes were on the programme - until you have done a few, you do not overcome a natural fear of them and they are an integral part of sailing a small dinghy compe...

  19. Modeling of Ship Roll Dynamics and Its Coupling with Heave and Pitch

    Directory of Open Access Journals (Sweden)

    R. A. Ibrahim


    Full Text Available In order to study the dynamic behavior of ships navigating in severe environmental conditions it is imperative to develop their governing equations of motion taking into account the inherent nonlinearity of large-amplitude ship motion. The purpose of this paper is to present the coupled nonlinear equations of motion in heave, roll, and pitch based on physical grounds. The ingredients of the formulation are comprised of three main components. These are the inertia forces and moments, restoring forces and moments, and damping forces and moments with an emphasis to the roll damping moment. In the formulation of the restoring forces and moments, the influence of large-amplitude ship motions will be considered together with ocean wave loads. The special cases of coupled roll-pitch and purely roll equations of motion are obtained from the general formulation. The paper includes an assessment of roll stochastic stability and probabilistic approaches used to estimate the probability of capsizing and parameter identification.

  20. A Simple Laboratory Scale Model of Iceberg Dynamics and its Role in Undergraduate Education (United States)

    Burton, J. C.; MacAyeal, D. R.; Nakamura, N.


    Lab-scale models of geophysical phenomena have a long history in research and education. For example, at the University of Chicago, Dave Fultz developed laboratory-scale models of atmospheric flows. The results from his laboratory were so stimulating that similar laboratories were subsequently established at a number of other institutions. Today, the Dave Fultz Memorial Laboratory for Hydrodynamics ( teaches general circulation of the atmosphere and oceans to hundreds of students each year. Following this tradition, we have constructed a lab model of iceberg-capsize dynamics for use in the Fultz Laboratory, which focuses on the interface between glaciology and physical oceanography. The experiment consists of a 2.5 meter long wave tank containing water and plastic "icebergs". The motion of the icebergs is tracked using digital video. Movies can be found at: We have had 3 successful undergraduate interns with backgrounds in mathematics, engineering, and geosciences perform experiments, analyze data, and interpret results. In addition to iceberg dynamics, the wave-tank has served as a teaching tool in undergraduate classes studying dam-breaking and tsunami run-up. Motivated by the relatively inexpensive cost of our apparatus (~1K-2K dollars) and positive experiences of undergraduate students, we hope to serve as a model for undergraduate research and education that other universities may follow.

  1. The tower crane overturning the reason analysis of construction site and preventive measures%施工现场塔吊倾覆原因分析及预防措施

    Institute of Scientific and Technical Information of China (English)



    The tower crane is not only a main construction machinery of modern industrial and civil buildings, and large tower crane is widely used in power stations, nuclear power plants,Bridges,etc.Because of the particularity of tower crane structure and application, with more attention paid to the safety of tower crane, in tower crane safety accident,capsized tend to cause significant safety construction,combining with the engineering example of tower crane overturning reasons are analyzed, and preventive measures are put forward.%塔式起重机不仅是现代工业与民用建筑的主要施工机械,而且大型塔机还广泛应用于发电站、核电站、桥梁等。因为塔机结构和应用的特殊性,塔机的安全性越来越受到重视,在塔机的安全事故中,倾覆往往造成重大安全施工,本文结合工程实例对塔机的倾覆原因进行了分析,提出了预防措施。

  2. Nonlinear Container Ship Model for the Study of Parametric Roll Resonance

    Directory of Open Access Journals (Sweden)

    Christian Holden


    Full Text Available Parametric roll is a critical phenomenon for ships, whose onset may cause roll oscillations up to +-40 degrees, leading to very dangerous situations and possibly capsizing. Container ships have been shown to be particularly prone to parametric roll resonance when they are sailing in moderate to heavy head seas. A Matlab/Simulink parametric roll benchmark model for a large container ship has been implemented and validated against a wide set of experimental data. The model is a part of a Matlab/Simulink Toolbox (MSS, 2007. The benchmark implements a 3rd-order nonlinear model where the dynamics of roll is strongly coupled with the heave and pitch dynamics. The implemented model has shown good accuracy in predicting the container ship motions, both in the vertical plane and in the transversal one. Parametric roll has been reproduced for all the data sets in which it happened, and the model provides realistic results which are in good agreement with the model tank experiments.

  3. Numerical Simulation of Liquid Tank Sloshing and Pressure Calculation based on Volume of Fluid Method%基于VOF法的液舱晃荡数值模拟及载荷计算

    Institute of Scientific and Technical Information of China (English)



    建立了液舱晃荡的有限元模型,运用CFD计算软件Fluent 6.3模拟了单激励和耦合激励下不同舱室结构以及不同幅度的液舱晃荡,并计算监测点压力,得到了晃荡在激励下的变化规律.对仿真结果进行讨论分析.%As a common phenomenon in liquid motions, sloshing usually happens partially in a filled liquid tank of moving ship. When coupling with ship motions it can cause violent motions and even capsizing under extreme conditions. At the same time, the sloshing of liquid tank is a complex liquid motions phenomenon which represent strong nonlinear and randomness. Based on the CFD software Fluent 6.3, under the force of single degree of freedom and multi-degree of freedom which would reflect in various range of the sloshing, the paper numerically simulated the different tank structures, calculated the pressure of monitor points and obtained the variation law of sloshing under stimulation. The effects of the different forms of liquid tank sloshing and variation trend are discussed.

  4. A Design Outline for Floating Point Absorber Wave Energy Converters

    Directory of Open Access Journals (Sweden)

    Mohammed Faizal


    Full Text Available An overview of the most important development stages of floating point absorber wave energy converters is presented. At a given location, the wave energy resource has to be first assessed for varying seasons. The mechanisms used to convert wave energy to usable energy vary for different wave energy conversion systems. The power output of the generator will have variations due to varying incident waves. The wave structure-interaction leads to modifications in the incident waves; thus, the power output is also affected. The device has to be stable enough to prevent itself from capsizing. The point absorber will give optimum performance when the incident wave frequencies correspond to the natural frequency of the device. The methods for calculating natural frequencies for pitching and heaving systems are presented. Mooring systems maintain the point absorber at the desired location. Various mooring configurations as well as the most commonly used materials for mooring lines are discussed. An overview of scaled modelling is also presented.

  5. Dr. S. Donald (Don) Stookey (1915-2014): Pioneering Researcher and Adventurer (United States)

    Beall, George H.


    Don Stookey, the father of glass-ceramics, was a pioneer in inducing and understanding internal nucleation phenomena in glass. His early work on dense opal glasses and photosensitive precipitation of gold and silver in glass led to an amazing series of inventions: Fotalite, a photosensitive opal, chemically machined Fotoform and Fotoceram, and TiO2-nucleated Pyroceram products including missile nosecones and oven-proof cookware. He received a basic patent on glass-ceramics, which was contested and affirmed in court. Don was able to demonstrate a clear photochromic glass that showed reversible darkening for thousands of cycles. This material became a fixture in the ophthalmic industry. He went on to invent a full-color polychromatic glass, capable of yielding a permanent patterned and monolithic stained glass. In his life outside science, Don chaired an interfaith group that founded a home for the elderly in Corning. He was also a wilderness enthusiast, surviving a plane crash in the Arctic and two boat capsizings. Even in his later years, he continued fishing off the coast of Florida and on Lake Ontario and went solo on a trip to the Patagonian Andes. Don Stookey was a special person by any measure: an unassuming optimist, eminent scientist and inventor, adventurer, and a beloved family man. Introduction

  6. Herculaneum: Clues to Vesuvius eruption (United States)

    Richman, Barbara T.

    More than 80 skeletons have been unearthed in the ancient Mediterranean town of Herculaneum, west of Italy's Mount Vesuvius. This anthropological find corroborates a reinterpretation by three University of Rhode Island scientists of the sequence of the August A.D. 79 eruption of Vesuvius. In addition, the discovery is the first proof that large numbers of people perished as they tried to flee from the eruption, estimated to have been about 10 times more powerful than the May 1980 Mount St. Helens blast.‘Who says dead men don't talk? Their bones have something to say about them and their everyday lives,’ says Sara C. Bisel, a physical anthropologist who analyzed the skeletons. Among the remains are a cluster of skeletons from six adults, four children, and two infants trying to shield themselves from the volcanic onslaught; the skeleton of a sailor, still clutching an oar, lying on his back beside an 8-m-long capsized boat; a woman whose now bony hand was still graced with gem-encrusted gold rings; and a soldier (see Figure 1). From these and other finds the anthropological team was able to discern that the ancient Romans, on average, were shorter than modern citizens and, judging from the condition of some of the teeth, probably had a low-sugar diet.

  7. 风雨联合作用下高速列车受力数值模拟%Simulation of the action effect of wind-driven rain on high-speed train

    Institute of Scientific and Technical Information of China (English)

    敬俊娥; 高广军


    k-ε double equation turbulent model and discrete phase model were used in the research of the effect of different rainfall intensities,different wind speeds and different train velocityies on the flow field around the vehicle.The results show that the rain drops under the effect of cross wind crash on to the surface of the carriage and then splash,which change the roughness and smoothness of the surface of the carriage,So it leads to that the side force,lift force and capsizing moment increase gradually with the increase of wind speed,train speed and rainfall intensity.The dynamic load on train when bearing strong wind and rainfall is a little bigger than that when bearing only strong wind load.%采用双方程湍流模型和离散相模型相结合的方法,对不同降雨强度、横风风速和车速下高速运动车辆周围的流场进行研究.研究结果表明:在横风作用下,下落的雨滴与高速运行的列车发生碰撞,雨滴飞溅、改变了车身表面的粗糙度和不平整性,导致车辆运行横向力、升力和倾覆力矩均随着车速、风速和降雨强度的增大逐渐变大;伴随着降雨过程的强横风作用,车辆所受的气动载荷与强横风的单独作用情况下相比稍微增加.

  8. 电力推进系统功率限制控制策略在实船项目中的应用%Application of Power Limitation Control Strategy in Electric Propulsion System On Real Ship

    Institute of Scientific and Technical Information of China (English)



    采用电力推进的船舶中,推进系统是作为主要负载直接连接在船舶电网上,推进负荷的突变和电网结构的突变可能引起柴发机组过载、电网震荡甚至全船失电,此时船舶会面临失控的危险,甚至会倾覆,因此推进控制系统必须要与船舶电站进行协调控制,确保船舶电站的稳定和安全。本文针对以上存在的问题通过案例来引入功率限制的控制策略,并分析其实现过程和可行性,最后通过一些试验证明此方案确实可行。%The electric propulsion system is directly connected with the ship power station as the main load. Discontinuous propulsion load and the abnormal power station can lead to generator set overload, grid turbulence and even the whole ship power-loss. Now the ship will face the risk of out of control, even capsized, so the propulsion control system must be coordinated control with ship power station, ensure security and stability of ship power station. In this paper, power limit control strategy is introduced to solve the above mentioned problem, and its implementation procedure and feasibility are analyzed. Finally, this scheme is proved to be feasible by some experiments.

  9. The impact of words on children with ADHD and DAMP. Consequences for psychoanalytic technique. (United States)

    Salomonsson, Björn


    Children with attention-deficit/hyperactivity disorder (ADHD) and disorder of attention, motility control, and perception (DAMP) are often sensitive to the analyst's interventions. This is not always due to the literal import of the intervention. The children sometimes react as if the words were dangerous concrete objects, which they must physically fend off. The author traces this phenomenon to the child's unstable internal situation. A bad, un-containing internal object is easily awakened and threatens to expel the analyst's words independently of their content. This results in violent clinical situations. Infant research and psychoanalytic work with infants and mothers evince how a complex semiotic process develops between mother and baby. The prerequisite for this process to get started and maintained is a secure external object, which gradually is internalized. Findings from developmental research and clinical infant work are used to illuminate analytic work with children with ADHD and DAMP. Vignettes demonstrate how important it is for the analyst to phrase interpretations after having gauged the state of the analysand's internal object as well as his/her own countertransference. If this is overlooked, the psychoanalytic dialogue easily capsizes. The author provides some technical recommendations on the psychoanalysis of these children. As part of the theoretical discussion he raises the general question of how the representations, which the baby forms in interaction with the mother, and the analysand forms in interaction with the analyst, should be classified. Rather than dividing them into bipartite thing- or word-presentations (Freud), the author suggests C. S. Peirce's tripartite semiotic classification in that the baby forms representations of icons, indices, and symbols.

  10. 固定平台桩腿强度分析

    Institute of Scientific and Technical Information of China (English)



    浅海采油主要借助于海洋固定平台,平台强度直接关系着操作人员的生命安全.平台的倾覆或倒塌均可能导致生命丧失和海洋环境的污染,给国家经济和海洋环境带来不利的影响.桩腿是承受海洋平台重量和外部载荷的重要支撑部分,桩腿强度是否满足规范要求对平台的安全有着重要的现实意义.以埕岛油田某中心平台为例,对风、浪、流、冰载等载荷进行组合分析,计算分析和比较灌浆桩腿和非灌浆桩腿强度对平台安全的影响.%Shallow sea oil recovery mainly relies on offshore fixed platform and the platform strength is directly related to the life safety of the operators.The collapse or capsizing of the platform may cause the loss of life and the pollution of the marine environment, which will have a negative impact on the national economy and the marine environment. Spud legs are the major supporting components of the platform to bear the weight of the offshore platform itself as well as external loads. Whether the spud leg strength meets the requirements as specified in the relevant rules and regulations has an important practical significance to the platform safety. Taking the central platform in Cheng Dao oil field as the example, a combined analysis of the wind, wave, current and ice loads is carried out; calculation analysis and comparison of the strength and influences to the platform safety are made between of the grouted spud pile and the non grouted pile leg.

  11. Dynamic causal relationship between spot and period freight rates for dry bulk shipping——evidences based on actual monthly data of different shipping markets%干散货航运即期费率和远期费率的动态引导关系——基于不同船型运输市场的月度经验数据

    Institute of Scientific and Technical Information of China (English)



    利用干散货航运市场2002—2010年的月度数据,通过ECM模型对3种主要干散货船型的即期费率和远期费率之间的动态引导关系进行实证研究。结论表明:不同船型的即期运费之间、远期运费之间均不存在协整关系;同一船型的即期运费与远期运费之间存在协整关系;Capsize型船舶的即期运费引导远期运费,Panamax型船舶的即期运费和远期运费双向引导,而Handymax型船舶的远期运费引导即期运费;各类船型的即期费率和远期费率之间呈正相关关系,且船型越大,两者之间的弹性越高。%This paper made the empirical study on the dynamic causal relationship between spot and period freight rates for three kinds of dry bulk ships by means of ECM model based on monthly market data from 2002 to 2010.The conclusions show that,there exists no co-integration relationship both among spot freight rates and among period freight rates for different dry bulk ships;there exists co-integration relationship between spot and period freight rates for every kind of dry bulk ship;there is causality from spot freight rate to period freight rate for Capsize ship and mutual causality between spot and period freight rates for Panamax ship,while there is causality from period freight rate to spot freight rate for Handymax ship;there is positive relationship between spot and period freight rates for every kind of dry bulk ship,and the elasticity between them becomes higher and higher with the increasing of tonnage of ships.

  12. 基于BEKK方差模型的干散货航运市场间波动溢出效应分析%Analysis of Volatility Spillover Effect Among Dry Bulk Shipping Markets Based on BEKK Variance Model

    Institute of Scientific and Technical Information of China (English)

    范永辉; 杨华龙; 刘金霞


    In view of the interactive relationship among handysize, panamax and capsize dry bulk shipping markets, the dry bulk freight indexes of different vessel types issued by the Baltic Shipping Exchange were employed and the volatility spillover effect among three dry bulk shipping markets of different vessel types was studied by BEKK variance model of multivariate GARCH. It is pointed that capesize dry bulk shipping market has volatility spillover effect on handysize dry bulk shipping market and panamax dry bulk shipping market while handysize dry bulk shipping market and panamax dry bulk shipping market have no volatility spillover effect on capesize dry bulk shipping market, and there is a two-way volatility spillover effect between handysize dry bulk shipping market and panamax dry bulk shipping market. Wald test verified the correctness of above inference. The results can provide references for dry bulk shipping operators to avoid risk of market volatility.%针对灵便型、巴拿马型和海岬型干散货航运市场间的互动关系问题,选取波罗的海干散货运价指数,应用多元广义自回归条件异方差中的BEKK方差分析模型,研究了干散货航运市场间的波动溢出效应.发现海岬型干散货航运市场对灵便型和巴拿马型干散货航运市场存在波动溢出效应,而灵便型和巴拿马型干散货航运市场对海岬型干散货航运市场不存在波动溢出效应,灵便型干散货航运市场和巴拿马型干散货航运市场之间存在双向波动溢出效应,Wald检验验证了上述结论的正确性.从而可为航运经营者规避干散货航运市场波动风险提供决策参考.


    Institute of Scientific and Technical Information of China (English)


    There exist three types of convolution formulae for the efficientevaluation of gravity field convolution integrals,i.e.,the planar 2D convolution,the spherical 2D convolution and the spherical 1D convolution.The largest drawback of both the planar and the spherical 2D FFT methods is that,due to the approximations in the kernel function,only inexact results can be achieved.Apparently,the reason is the meridian convergence at higher latitudes.As the meridians converge,the Δφ,Δλ blocks do not form a rectangular grid,as is assumed in 2D FFT methods.It should be pointed out that the meridian convergence not only leads to an approximation error in the kernel function,but also causes an approximation error during the implementation of 2D FFT in computer.In order to meet the increasing need for precise determination of the vertical deflections,this paper derives a more precise planar 2D FFT formula for the computation of the vertical deflections.After having made a detailed comparison between the planar and the spherical 2D FFT formulae,we find out the main source of errors causing the loss in accuracy by applying the conventional spherical 2D FFT method.And then,a modified spherical 2D FFT formula for the computation of the vertical deflections is developed in this paper.A series of numerical tests have been carried out to illustrate the improvement made upon the old spherical 2D FFT.The second part of this paper is to discuss the influences of the spherical harmonic reference field,the limited capsize,and the singular integral on the computation of the vertical deflections.The results of the vertical deflections over China by applying the spherical 1D FFT formula with different integration radii have been compared to the astro-observed vertical deflections in the South China Sea to obtain a set of optimum deflection computation parameters.

  14. Cause analysis of an extreme gale event occurred in Jianli on 1 June 2015 based on Doppler weather radar data%基于多普勒天气雷达资料的“6.1”监利极端大风成因分析

    Institute of Scientific and Technical Information of China (English)

    唐明晖; 姚秀萍; 杨湘婧; 徐靖宇


    An extreme gale event, hereinafter referred to as“6.1”gale event, occurred in Jianli, Hubei on 1 June 2015, which is triggered by downburst and caused the capsizing accident of cruise ship“Dongfangzhixing”. Using data from conventional meteorological observations, in-tensive automatic weather station, radiosonde, Doppler weather radar and NCEP reanalysis, we have analyzed the environmental conditions and influencing systems of the“6.1”gale event, with special emphasis on analyzing its cause based radar data. Results are as follows. (1) The“6.1”gale event occurred under some favorable conditions such as strong low-level vertical wind shear and lower-than-normal convection condensation level, and it is triggered by the development of mesoscale vortex at ground level and cold front. (2) This event is caused by linear multicell storm, in which there are accompanied by the supercells and emerged mesocyclones within the serial volume scans. (3) Mesocy-clones revolved in high-speed and their bottom descended continuously after the storm cells developed into supercells, which can be the indi-cation of tornado. (4) The development of a high value center of velocity at low elevation was observed during and prior to the occurrence of the extreme gale (hereinafter referred to as“extreme gale”) caused by the downburst that led to the capsizing accident of cruise ship“Dongfang-zhixing”. The characteristics of mesocyclone in the storm cell have not been clear when the extreme gale occurred. In addition, strong reflec-tivity factor core descended continuously within the five serial volume scans before the extreme gale. (5) Radar radial velocity, storm quality charts and mesocyclone quality charts are important indicators for the early warning of the“6.1”gale event. And storm evolution, mesocy-clone quality charts and high value center of velocity at lower elevation angle all can be certainly served as a reference before the extreme gale occurred.%2015

  15. The City Image of Dostoevsky's Petersburg%陀思妥耶夫斯基笔下的彼得堡城市意象

    Institute of Scientific and Technical Information of China (English)

    傅星寰; 张一莹


    陀思妥耶夫斯基笔下的彼得堡城市意象——阴郁之花、神幻之城、罪恶之都、呼求悔改的"尼尼微",传达和推进了他的"彼得堡文本"的主题——"人之谜"的情感哲思、对俄罗斯现代性地批判、给予俄罗斯以及俄罗斯人未来道路选择的箴言,统摄着他的"彼得堡文本"的氛围和基调,形成了他富有特殊魅力的艺术表现.这些融入作家感怀的城市意象,源于现实又超越于现实之上,饱含了作家的文化批判及预言性质的深刻洞见.这些意象最终指向彼得堡的救赎之路,陀氏看到了传统观念终将经受洪水而倾覆的彼得堡有在信仰中被赎救的可能,从而藉着他的"彼得堡文本",给予彼得堡传统末日神话一个新的出路,盼望彼得堡成为响应呼召悔改后"新生"的城市.%The city image of Dostoevsky's Petersburg —Dark flowers,Magic City,Sin City,Call for repen-tance's 'Nineveh',communicated and promoted his "Petersburg text" theme—the emotion philosophy a-bout "mystery of the people",the modernity criticism of Russia,the proverbs given to choose the future path of Russia and the Russian,controlled his "Petersburg text" atmosphere and tone,and formed the special charm of artistic expression.These city images,which reflect the writer's lament and sentiment, come from life and beyond the reality,and fully reflect the writer's profound insight of cultural criticism and prophetic nature.These images finally point to the redemption road of Petersburg.Dostoevsky per-ceived that the traditional Petersburg would be capsized by flood finally,and there was possible to be saved in faith.Thereby,Dostoevsky created a new way for traditional doomsday myth of Petersburg via his"Pe-tersburg text",and hoped that Petersburg would become a"new city",which responses to calling for the repentance.

  16. 单侧性真皮中层弹性组织溶解症一例%A case of unilateral mid-dermal elastolysis

    Institute of Scientific and Technical Information of China (English)

    马寒; 谢淑霞; 苏向阳; 李美荣; 尹颂超; 陆春


    A 38-year-old woman presented with a 20-year history of yellow papules and band-like atrophy on the right neck. The lesions developed slowly and were asymptomatic. There was no history of long-term sun exposure or family history of similar diseases. Skin examination revealed multiple irregularly sized yellow papules and plaques on the right anterior neck following cleavage lines, multiple pin cap-sized perifollicular papules on the posterior right neck. Well-defined band-like atrophic patches with fine wrinkling were observed in the whole right neck, giving an aged appearance. The skin of the left neck was nearly normal. Pathological examination of biopsy specimens from the yellow papules showed a normal epidermis, scant lymphohistiocytic and melanophage infiltrates around the vessels in the superficial dermis without solar degradation. The collagen bundles in the mid dermis were slightly thickened and arranged tightly in parallel to the skin surface with the absence of inflammatory infiltrate. Verhoeff-van Giesen's staining confirmed a nearly complete absence of elastic fibers in the mid dermis as well as obvious swelling and breakage of resident scant elastic fibers. Von Kossa's staining was negative. Based on the above findings, the diagnosis was made as unilateral mid-dermal elastolysis.%患者女,38岁,颈右侧黄色丘疹伴带状萎缩20年。皮损缓慢发展,无明显症状。否认有长期日晒及家族史。皮肤科检查:颈右前侧皮肤见沿皮纹方向、大小不一的黄色丘疹、斑块;颈右后侧见多数以毛囊为中心的针帽大丘疹;整个颈右侧皮肤呈境界较清楚的带状萎缩斑,表面为细皱纹样改变,似老年人皮肤外观。颈部左侧皮肤大致正常,黄色丘疹处组织病理检查:表皮大致正常;真皮浅层血管周稀疏淋巴组织细胞及少量噬黑素细胞浸润,未见日光性变性改变;真皮中层胶原纤维增粗,排列紧密,未见明显炎细胞浸润

  17. La banque de données platform de l'Institut français du pétrole : un outil de base pour des études de risque Ifp's Platform Databank: a Basic Implement for Risk Analysis

    Directory of Open Access Journals (Sweden)

    Bertrand A. R. V.


    having actually led to accidents. Such figures are very much appreciated in safety risk analysis. Several statistical results are given to illustrate PLATFORM's capacities. An analysis of activity at the time of the accident shows that most accidents occurred (in order during exploration drilling, during production, while rigs were under tow, while rigs were shut down during a storm, during development drilling, and during jacking-up or jacking-down for this type of mobile platform. In fact, 76. 6% of the accidents to jackups occurred either during towing (30. 9%, exploration drilling (27. 1% or jacking operations (18. 6%. Accidents to fixed platforms occurred predominantly during production (53%. The most frequent types of accident were found to be (in order blowouts, explosions or fires, damage to legs or mats often due to the sea floor, capsizing of the rig, gas kicks and structural cracks. But the major risk varied according to the type of platform : gas blowouts for submersibles, fire/explosions for fixed production platforms, capsizing for barges, sea floor accidents for jackups, gas kicks for drillships and semi-submersibles. A geographic analysis gives the Louisiana sector of the Gulf of Mexico a higher percentage of accidents (37% than the Texas sector (7. 5% or the Scottish North Sea (8%. This can easily be explained both by the relative importance of petroleum activity in the sector (especially barges and submersibles operating in swamps, lakes and deltas and by the comparable wealth of information made public in this region. A further analysis of the region shows more gas blowouts (28% than the world average (21% and, on the other hand, a chronological decrease in accidents linked to structural resistance, reflecting better rig design and reliability over the years. In general, statistics of accidents, correlated to offshore oil activity, show that accidents are decreasing in the Gulf of Mexico and in Persian Gulf, whereas there are more in the North Sea

  18. 包裹式加筋土挡土墙抗震试验分析%Seismic Tests and Analysis of Warped Reinforced Earth-retaining Wall

    Institute of Scientific and Technical Information of China (English)

    李庆海; 王炳锟; 蒋楚生; 段忠臣


    Research purposes: According to the engineering features of the Xiangyun Station of Guangtong-Dali Railway, the research was done on the reinforcing mechanism, load bearing, deformation, design methods, computing theory and the failure mode of the wraped reinforced earth-retaining wall under earthquake effect to improve the computing theory and numerical simulation method for the seismic design of the reinforced earth-retaining wall and promote the application of reinforced earth-retaining wall in engineering. Research conclusions; The warped reinforced earth-retaining wall is better than the ordinary earth-retaining wall in seismic property because the wrapped effect can make seismic wave weak during the propagation and amplification of the seismic wave along the wall up. When in 0. 4 g and 0. 616 g , the model produced the evident seismic fall, and cracks happened in the junctions between the wall panel and the reinforced soil and between the reinforced soil and the unreinforced soil. In the peak acceleration, the potential fracture surface of these two kinds of experimental models were distributed in the same position, approximate to 0.45 H vertical line. But in the "Code for Design of Retaining Structure of Railway Subgrade" (TB 10025-2006) , the potential fracture surface is approximate to 0.3 H vertical line and it slants to unsafety. So the reinforcing length should be increased in design. From the theoretical calculation and the analysis results of the internal and external stability of the reinforced earth-retaining wall obtained by the test data calculation, it was seen the coefficient of sliding resistance, the coefficient of capsizing resistance, the coefficient of uplifting resistance of the whole wall and the coefficient of uplifting resistance of the geogrid in various layers obtained by theoretical calculation were larger than the test data calculation. This showed the current code was unsafe and could be properly modified.%研究目的:针对广

  19. Nano-biomedical approaches of cancer therapy using carbon based and magnetic nanomaterials (United States)

    Karmakar, Alokita

    the higher accumulation EGF targeted SWCNTs to PANC-1 cells. In chapter 4, we have explored the multimodality of nanotechnology by using EGF-functionalized iron cored, carbon shelled (FeC) magnetic nanoprticle that can generate heat when exposed to radiofrequency (RF). This process called hyperthermia, which is an effective way to kill different cancer cells as cancer cells are most susceptible to heat increase beyond a threshold level compared to normal cells. By targeting the nanoparticles this process was made more efficient by selectively populating magnetic nanoparticles specifically in cancer cells only. Two different cells line, MCF-7 and PANC-1 were incubated with the magnetic nanopartilces for 24 hours followed by exposure to the RF (350KHz, 5kW) for 10 min. EB/AO and flow-cytometry were used to determine the apoptotic and necrotic cells. EGF targeted FeC was superior in apoptosis induction in both cell lines, while the untargeted nanoparticles showed little effect. The MCF-7 cells were more vulnerable to the targeted FeC nanoparticles compared to PANC-1 cells. Caspase-8 and caspase-3 assays were done to provide the involvement of these two capsizes in two different cell lines. To enhance the therapeutic efficiency of anticancer drug, two FDA approved anticancer drugs doxorubicin and erlotinib were loaded on FeC nanoparticles (Chapter 5). The loading capacity was determined by UV-Vis spectroscopy. MTT assay was also used to determine the loaded and unloaded forms of drug. RF treatment was used to generate hyperthermia and which also helps in releasing the drug from nanoparticles. Flow-cytomertic detection of apoptosis showed above 90% cells died after combined hyperthermia and doxorubicin treatment. Graphene is a 2D carbon nanoparticle that has been proven to be an excellent carrier of chemotherapeutic drugs. In chapter 6, -COOH functionalized graphene (FG) was used to deliver a potent but extremely hydrophobic and water insoluble drug, parthenolide (PTL), to

  20. Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars. (United States)

    Gallagher, C.; Balme, M. R.


    role in at least one mode of catena formation [2]. As well as presenting the morphological evidence for a genetic association between TPT and pit catenas, we present corroborative evidence that fluvial channel networks on Mars have in places increased in complexity through the linking of pits arranged in linear to arcuate arrays, culminating in a pseudo-branching channel network. Such systems do not occur at topographic margins and did not disintegrate into stepped crustal blocks. However, the scale of these channels and the volumes of liquid intermittently impounded in craters along these channel systems indicate that pit chains are associated with significant excess groundwater production leading to channelized flow, including catastrophic discharges when crater-impounded lakes along-flow were breached. Are the MDB and Isidis cone chains exhumed pit catenas and are the pits the surface expression of more deep-seated conduits? Do pit catenas indicate excess pore-water production, sufficient to link individual pits and dissect crustal blocks? Together, do these assemblages reflect the degradation of the MDB and Isidis margins and the subsequent stripping of adjacent low-lying plains? The crucial observations presented in this research (cone chains lying between crustal blocks, together with the morphometric similarities) are consistent with the interpretation of the cones and catenas having a common origin. Consequently, we hypothesise that the translated, back-rotated, tilted and capsized disposition of en echelon blocks is very reminiscent of the morphology produced during lateral spreading [3] associated with stratabound liquefaction below a low-gradient, rigid, insensitive surface. Significantly, such liquefaction events cause extensive, arcuate ground fractures along with the discharge of sediment-laden groundwater from the liquefiable substratum to the surface through pipes and conical boils confined within inter-block fractures. These conduits and their