Unique ecological impacts associated with offshore floating nuclear power plants

International Nuclear Information System (INIS)

Adams, S.M.; McLean, R.B.

1979-01-01

The ecological impacts that could occur as a result of site construction and operation of an offshore floating nuclear power plant are identified by comparing the principal ecological features associated with offshore siting with those associated with the siting of onshore estuarine plants. In general, the ecological impacts of offshore nuclear plants should be relatively smaller than those of estuarine plants. Possible factors that could increase the relative impacts of offshore plants are high frequency of contact with schools of fish, siting near inlets to estuaries or other ecologically important areas, and the persistence of halogen residuals. Identifying the potential ecological impacts associated with the siting of offshore plants permits the development of various monitoring programs and measures to minimize these impacts

Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length

Energy Technology Data Exchange (ETDEWEB)

Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.

2013-07-01

With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.

Recovery of uranium from seawater using wave power and floating offshore units

International Nuclear Information System (INIS)

Bjoerk, B.; Vallander, P.

1981-03-01

This report is the final contribution to a study of the technical and economic feasibility of floating units for the recovery of uranium from seawater. The seawater is supplied by wave energy and received by a sloping plane. An optimization was carried out which involved study of the number of storeys of adsorbent beds in a floating unit, the number and tonnage of service vessels and the number of moorings. Different absorbent bed areas, thicknesses of layers of adsorbent material, length of floating units and length of extraction cycles were considered. The annual uranium uptake was calculated for an offshore location 20 nautical miles to the south-east of South Africa. The costs of the total plant for each combination of optimization parameters were calculated and are presented. The cost of the recovered uranium for each combination of optimization parameters is shown. The most feasible offshore plant will recover uranium at a cost of about 1 900 SEK/kg. It will comprise 22 floating units, each with an adsorbent bed area of 300 m 2 per metre of the unit and an adsorbent thickness of 0.10 metres. A conceptual layout of the selected floating unit is shown in drawings. (author)

Floating Offshore Wind in Hawaii: Potential for Jobs and Economic Impacts from Three Future Scenarios

Energy Technology Data Exchange (ETDEWEB)

Jimenez, Tony; Keyser, David; Tegen, Suzanne

2016-04-18

Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to be anchored to the deeper seafloor if deployed in Hawaiian waters. To analyze the employment and economic potential for floating offshore wind off Hawaii's coasts, the Bureau of Ocean Energy Management commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical deployment scenarios for Hawaii: 400 MW of offshore wind by 2050 and 800 MW of offshore wind by 2050. The results of this analysis can be used to better understand the general scale of economic opportunities that could result from offshore wind development.

Floating Offshore Wind in Oregon: Potential for Jobs and Economic Impacts from Two Future Scenarios

Energy Technology Data Exchange (ETDEWEB)

Jimenez, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Speer, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-05-01

Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for Oregon: 5,500 megawatts (MW) of offshore wind deployment in Oregon by 2050 (Scenario A), and 2,900 MW of offshore wind by 2050 (Scenario B). These levels of deployment could power approximately 1,600,000 homes (Scenario A) or 870,000 homes (Scenario B). Offshore wind would contribute to economic development in Oregon in the near future, and more substantially in the long term, especially if equipment and labor are sourced from within the state. According to the analysis, over the 2020-2050 period, Oregon floating offshore wind facilities could support 65,000-97,000 job-years and add $6.8 billion-$9.9 billion to the state GDP (Scenario A).

Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine

Energy Technology Data Exchange (ETDEWEB)

Roald, L.; Jonkman, J.; Robertson, A.

2014-05-01

The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.

Influence of Model Simplifications Excitation Force in Surge for a Floating Foundation for Offshore Wind Turbines

DEFF Research Database (Denmark)

Andersen, Morten Thøtt; Hindhede, Dennis; Lauridsen, Jimmy

2015-01-01

As offshore wind turbines move towards deeper and more distant sites, the concept of floating foundations is a potential technically and economically attractive alternative to the traditional fixed foundations. Unlike the well-studied monopile, the geometry of a floating foundation is complex and...

Investigation of the effects of platform motion on the aerodynamics of a floating offshore wind turbine

Institute of Scientific and Technical Information of China (English)

万德成

2016-01-01

Along with the flourishing of the wind energy industry, floating offshore wind turbines have aroused much interest among the academia as well as enterprises. In this paper, the effects of the supporting platform motion on the aerodynamics of a floating wind turbine are studied using the open source CFD framework OpenFOAM. The platform motion responses, including surge, heave and pitch, are superimposed onto the rotation of the wind turbine. Thrust and torque on the wind turbine are compared and analysed for the cases of different platform motion patterns together with the flow field. It is shown that the movement of the supporting platform can have large influences on a floating offshore wind turbine and thus needs to be considered carefully during the design process.

Floating Offshore Wind in California: Gross Potential for Jobs and Economic Impacts from Two Future Scenarios

Energy Technology Data Exchange (ETDEWEB)

Speer, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-04-18

Construction of the first offshore wind farm in the United States began in 2015, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) has commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for California: 16 GW of offshore wind by 2050 (Scenario A) and 10 GW of offshore wind by 2050 (Scenario B). The results of this analysis can be used to better understand the general scales of economic opportunities that could result from offshore wind development. Results show total state gross domestic product (GDP) impacts of $16.2 billion in Scenario B or $39.7 billion in Scenario A for construction; and $3.5 billion in Scenario B or $7.9 billion in Scenario A for the operations phases.

Recovery of uranium from seawater using wave power and floating offshore units

International Nuclear Information System (INIS)

Bjoerk, B.; Vallander, P.

1981-06-01

This report is a final contribution to a study of the technical and economic feasibility of floating units for the recovery of uranium from seawater. The seawater is supplied by wave energy and received by a sloping plane. An optimization was carried out which involved study of the number of storeys of adsorbent beds in a floating unit, the number and tonnage of service vessels and the number of moorings. Different adsorbent bed areas, thickness of layers of adsorbent material, length of floating units and length of extraction cycles were considered. The costs of a plant for each combination of optimization parameters were calculated and are presented. The most feasible offshore plant will recover uranium at a cost of about 1900 SEK/kg. It will comprise 22 floating units, each with an adsorbent bed area of 300 m 2 per metre of the unit and an adsorbent thickness of 0.10 metres. (Authors)

A Floating Offshore Wind Turbine in Extreme Wave Conditions

DEFF Research Database (Denmark)

Wehmeyer, Christof

is an expected maximum wave in accordance with a Rayleigh distribution. The maximum waves are numerically represented by embedded Stream-function waves. The author compares the resulting bow tendon loading of the hybrid model to the measured responses, as a key performance indicator. 90% to 95% of the loads show...... a satisfying match, though the hybrid model over predicts the remaining 5% to 10% maximum loads by 32%, 34% and 29% for a linear irregular sea state, a nonlinear irregular sea state and a nonlinear irregular sea state with an embedded Stream-function wave, respectively. The limited number of sea states during...... important aspects, which make them non-conservative in use for FOWT: (A) The offshore wind industry intends to install floating structures at much lower water depth (from 50m onwards), than the offshore oil & gas industry (from 300m onwards). In such cases a linear wave theory approach might...

Smart Novel Semi-Active Tuned Mass Damper for Fixed-Bottom and Floating Offshore Wind (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Tsouroukdissian, Arturo [Alstom Renewable US LLC

2016-05-02

The intention of this paper is to present the results of a novel smart semi-active tuned mass damper (SA-TMD), which mitigates unwanted loads for both fixed-bottom and floating offshore wind systems. (Presentation Format).

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-08-01

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.

Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling; Preprint

Energy Technology Data Exchange (ETDEWEB)

Jonkman, J.; Larsen, T.; Hansen, A.; Nygaard, T.; Maus, K.; Karimirad, M.; Gao, Z.; Moan, T.; Fylling, I.

2010-04-01

Offshore wind turbines are designed and analyzed using comprehensive simulation codes that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structure. This paper describes the latest findings of the code-to-code verification activities of the Offshore Code Comparison Collaboration, which operates under Subtask 2 of the International Energy Agency Wind Task 23. In the latest phase of the project, participants used an assortment of codes to model the coupled dynamic response of a 5-MW wind turbine installed on a floating spar buoy in 320 m of water. Code predictions were compared from load-case simulations selected to test different model features. The comparisons have resulted in a greater understanding of offshore floating wind turbine dynamics and modeling techniques, and better knowledge of the validity of various approximations. The lessons learned from this exercise have improved the participants' codes, thus improving the standard of offshore wind turbine modeling.

Computational Fluid Dynamic Analysis of a Floating Offshore Wind Turbine Experiencing Platform Pitching Motion

Directory of Open Access Journals (Sweden)

Thanhtoan Tran

2014-08-01

Full Text Available The objective of this study is to illustrate the unsteady aerodynamic effects of a floating offshore wind turbine experiencing the prescribed pitching motion of a supporting floating platform as a sine function. The three-dimensional, unsteady Reynolds Averaged Navier-Stokes equations with the shear-stress transport (SST k-ω turbulence model were applied. Moreover, an overset grid approach was used to model the rigid body motion of a wind turbine blade. The current simulation results are compared to various approaches from previous studies. The unsteady aerodynamic loads of the blade were demonstrated to change drastically with respect to the frequency and amplitude of platform motion.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions.

Science.gov (United States)

Xu, B F; Wang, T G; Yuan, Y; Cao, J F

2015-02-28

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Uncertainty Analysis of OC5-DeepCwind Floating Semisubmersible Offshore Wind Test Campaign: Preprint

Energy Technology Data Exchange (ETDEWEB)

Robertson, Amy N [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-07-26

This paper examines how to assess the uncertainty levels for test measurements of the Offshore Code Comparison, Continued, with Correlation (OC5)-DeepCwind floating offshore wind system, examined within the OC5 project. The goal of the OC5 project was to validate the accuracy of ultimate and fatigue load estimates from a numerical model of the floating semisubmersible using data measured during scaled tank testing of the system under wind and wave loading. The examination of uncertainty was done after the test, and it was found that the limited amount of data available did not allow for an acceptable uncertainty assessment. Therefore, this paper instead qualitatively examines the sources of uncertainty associated with this test to start a discussion of how to assess uncertainty for these types of experiments and to summarize what should be done during future testing to acquire the information needed for a proper uncertainty assessment. Foremost, future validation campaigns should initiate numerical modeling before testing to guide the test campaign, which should include a rigorous assessment of uncertainty, and perform validation during testing to ensure that the tests address all of the validation needs.

Aeroelastic impact of above-rated wave-induced structural motions on the near-wake stability of a floating offshore wind turbine rotor

Science.gov (United States)

Rodriguez, Steven; Jaworski, Justin

2017-11-01

The impact of above-rated wave-induced motions on the stability of floating offshore wind turbine near-wakes is studied numerically. The rotor near-wake is generated using a lifting-line free vortex wake method, which is strongly coupled to a finite element solver for kinematically nonlinear blade deformations. A synthetic time series of relatively high-amplitude/high-frequency representative of above-rated conditions of the NREL 5MW referece wind turbine is imposed on the rotor structure. To evaluate the impact of these above-rated conditions, a linear stability analysis is first performed on the near wake generated by a fixed-tower wind turbine configuration at above-rated inflow conditions. The platform motion is then introduced via synthetic time series, and a stability analysis is performed on the wake generated by the floating offshore wind turbine at the same above-rated inflow conditions. The stability trends (disturbance modes versus the divergence rate of vortex structures) of the two analyses are compared to identify the impact that above-rated wave-induced structural motions have on the stability of the floating offshore wind turbine wake.

Existing methodologies in the design and analysis of offshore floating nuclear power plants

International Nuclear Information System (INIS)

Thangam Babu, P.V.; Reddy, D.V.

1977-01-01

The paper presents a comprehensive state-of-the-art on the design and analysis of Floating Nuclear Power Plants (FNPs). The recent accelerated growth of the offshore oil industry has considerably increased the confidence in the offshore FNP concept, in view of the vast potential for the transposition of available technology. The main advantages of FNPs are: (1) unlimited supply of the cooling water, (2) isolation of thermal, noise and radioactive pollution, (3) elimination of the need for large areas of unoccupied lands usually required for safety precaution, and (4) financial savings by using standardised design and production line approach. The topics covered in this paper are: Offshore Concept Evaluations; Siting Considerations; Design Considerations; Analysis; and Miscellaneous Considerations. (Fatigue and crack propagation, Model Studies and experimental investigation, Seismic instrumentation, Noise and vibration level considerations, Safety). A detailed bibliography is presented to indicate the immediate need for further research in the areas of dynamic analysis using improved mathematical modelling techniques incorporating water-structure interaction, and nonlinear effects of the supporting medium and the mooring system; safety analysis of FNPs to accident

Dynamic characteristics between waves and a floating cylindrical body connected to a tension-leg mooring cable placed in a simulated offshore environment

Directory of Open Access Journals (Sweden)

Juhun Song

2016-07-01

Full Text Available Given the rapid progress made in understanding the dynamics of an offshore floating body in an ocean environment, the present study aimed to simulate ocean waves in a small-sized wave flume and to observe the motion of a cylindrical floating body placed in an offshore environment. To generate regular ocean waves in a wave flume, we combined a wave generator and a wave absorber. In addition, to precisely visualise the oscillation of the body, a set of light-emitting diode illuminators and a high-speed charge-coupled device camera were installed in the flume. This study also focuses on the spectral analysis of the movement of the floating body. The wave generator and absorbers worked well to simulate stable regular waves. In addition, the simulated waves agreed well with the plane waves predicted by shallow-water theory. As the period of the oncoming waves changed, the movement of the floating body was substantially different when tethered to a tension-leg mooring cable. In particular, when connected to the tension-leg mooring cable, the natural frequency of the floating body appeared suddenly at 0.391 Hz as the wave period increased.

Some aspects of arctic offshore floating structures

Energy Technology Data Exchange (ETDEWEB)

Lubbad, Raed Khalil

2011-01-15

The present work highlights some aspects related to the analyses of Arctic offshore floating structures. This thesis consists of five papers, which can be divided into two main categories. One category deals with the dynamics of slender structures with an emphasis on the prediction and suppression of vortex induced vibrations (VIV), and the other category examines the process of interaction between sloping structures and sea ice with focus on developing a numerical model to simulate this process in real time. Slender structures, such as mooring lines and marine risers, are very important for the offshore petroleum industry, which is currently approaching deeper waters. Increasingly, attention has been focused on predicting the susceptibility of these structures to VIV. In this thesis, two asymptotic techniques namely, the local analysis and the WKB methods, were used to derive closed-form solutions for the natural frequencies and mode shapes of slender line-like structures. Both the top-tensioned nearly-vertical configuration and the catenary configuration were considered. The accuracy of the solutions derived was established through comparison with other analytic solution techniques and with results of numerical finite element solutions. The effects of the bending stiffness and the effects of approximating the tension variation as a linear function were discussed. Experimental data on the multi-modal in-line and cross-flow response behaviour of a towed catenary model were analysed to examine the usefulness of the solutions for predicting the response frequencies and envelopes due to VIV. Helical strakes are often used as a mitigating measure to suppress the VIV of slender structures. This thesis presented an innovative method to fit ropes helically to a riser in the installation phase. Such a procedure will help to overcome the handling problem associated with the use of conventional sharp-edged strakes. Experimental investigations were then performed to verify

Spar-type platform design for the offshore floating nuclear power plant

International Nuclear Information System (INIS)

Jurewicz, Jacob; Buongiorno, Jacopo; Todreas, Neil; Golay, Michael

2014-01-01

There exists the potential for substantial gains in safety, physical security, and economics for nuclear electricity supply through the development of an Offshore Floating Nuclear Plant (OFNP). Utilizing the most reliable and efficient construction techniques, this plant can be built from modular components in a shipyard as a partially submerged floating spar platform. The plant can then be floated to a site between 5 and 10 miles off the coast, moored in approximately 100-meter deep water, and connected to the grid via an underwater transmission line. The OFNP is designed to take full advantage of its environment to include passive cooling systems that eliminate the loss of ultimate heat sink accident, thereby decreasing the likelihood of severe accidents. The platform’s structural design, mooring system, and siting protect it against severe weather systems and render it immune to tsunamis and seismic activity. Furthermore, the OFNP containment design and venting procedures effectively eliminate the threat of serious land contamination, should a severe accident actually occur. The OFNP overall design builds on decades of offshore oil drilling experience and is derived from a shortened cylindrical spar platform. The platform has a skirt diameter of 75 m, a waterline diameter of 45 m, an operational draft of 48.5 m, and a total weight of about 38,200 tons when the skirt is empty. The spar design maximizes hydrodynamic stability, has been tested in various locations around the world in oil extraction, and offers significant protection to critical systems from external threats. The reactor containment is located below sea level and centered in a hull surrounded by seawater. This positioning offers both considerable physical security as well as unique opportunities in passive cooling. Watertight levels house safety critical systems (e.g. reactor, spent fuel pool, control room, battery room), the steam cycle, the condensate storage tank, and the desalination plant

Experimental investigations on the aerodynamics and aeromechanics of wind turbines for floating offshore applications

Science.gov (United States)

Khosravi, Morteza

There are many advantages in floating wind turbines in deep waters, however, there are also significant technological challenges associated with it too. The dynamic excitation of wind and waves can induce excessive motions along each of the 6 degrees of freedom (6-DOF) of the floating platforms. These motions will then be transferred to the turbine, and directly impact the wake characteristics of the floating wind turbines, and consequently the resultant wind loadings and performances of the wind turbines sited in offshore wind farms. In the present study, a comprehensive experimental study was performed to analyze the performance, loading, and the near wake characteristics of a rigid wind turbine model subjected to surge, heave, and pitch motions. The experimental study was performed in a large-scale atmospheric boundary layer wind tunnel with a scaled three-blade Horizontal Axial Wind Turbine model placed in a turbulent boundary layer airflow with similar mean and turbulence characteristics as those over a typical offshore wind farm. The base of the 1:300 scaled model wind turbine was mounted on translation and rotation stages. These stages can be controlled to generate surge, pitch and heave motions to simulate the dynamic motions experienced by floating offshore wind turbines. During the experiments, the velocity scaling method was chosen to maintain the similar velocity ratios (i.e., the ratios of the incoming airflow flow to that of turbine base motion) between the model and the prototype. During the experiments, a high resolution digital particle image velocimetry (PIV) system was used to achieve flow field measurements to quantify the characteristics of the turbulent vortex flow in the near wake of the wind turbine model. Besides conducting ''free run'' PIV measurements to determine the ensemble-averaged statistics of the flow quantities such as mean velocity, Reynolds stress, and turbulence kinetic energy (TKE) distributions in the wake flow, ''phase

Smart Novel Semi-Active Tuned Mass Damper for Fixed-Bottom and Floating Offshore Wind (Paper)

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Tsouroukdissian, Arturo [Alstom Renewable US LLC (GE Subsidiary); Lackner, Mathew [University of Massachusetts; Cross-Whiter, John [Glosten Associates; Park, Se Myung [University of Massachusetts; Pourazarm, Pariya [University of Massachusetts; La Cava, William [University of Massachusetts; Lee, Sungho [Glosten Associates

2016-05-02

The intention of this paper is to present the results of a novel smart semi-active tuned mass damper (SA-TMD), which mitigates unwanted loads for both fixed-bottom and floating offshore wind systems. The paper will focus on the most challenging water depths for both fixed-bottom and floating systems. A close to 38m Monopile and 55m Tension Leg Platform (TLP) will be considered. A technical development and trade-off analysis will be presented comparing the new system with existing passive non-linear TMD (N-TMD) technology and semi-active. TheSATMD works passively and activates itself with low power source under unwanted dynamic loading in less than 60msec. It is composed of both variable stiffness and damping elements coupled to a central pendulum mass. The analysis has been done numerically in both FAST(NREL) and Orcaflex (Orcina), and integrated in the Wind Turbine system employing CAD/CAE. The results of this work will pave the way for experimental testing to complete the technology qualification process. The load reductions under extreme and fatigue cases reach up significant levels at tower base, consequently reducing LCOE for fixed-bottom to floating wind solutions. The nacelle acceleration is reduced substantially under severe random wind and sea states, reducing the risks of failure of electromechanical components and blades at the rotor nacelle assembly. The SA-TMD system isa new technology that has not been applied previously in wind solutions. Structural damping devices aim to increase offshore wind turbine system robustness and reliability, which eases multiple substructures installations and global stability.

WindFloat Pacific Project, Final Scientific and Technical Report

Energy Technology Data Exchange (ETDEWEB)

Banister, Kevin [Principle Power, Inc., Emeryville, CA (United States)

2017-01-17

PPI’s WindFloat Pacific project (WFP) was an up to 30 MW floating offshore wind demonstration project proposed off the Coast of Oregon. The project was to be sited approximately 18 miles due west of Coos Bay, in over 1000 ft. of water, and is the first floating offshore wind array proposed in the United States, and the first offshore wind project of any kind proposed off the West Coast. PPI’s WindFloat, a semi-submersible foundation designed for high-capacity (6MW+) offshore wind turbines, is at the heart of the proposed project, and enables access to the world class wind resource at the project site and, equally, to other deep water, high wind resource areas around the country.

An Aeroelastic Perspective of Floating Offshore Wind Turbine Wake Formation and Instability

Science.gov (United States)

Rodriguez, Steven N.; Jaworski, Justin W.

2015-11-01

The wake formation and wake stability of floating offshore wind turbines are investigated from an aeroelastic perspective. The aeroelastic model is composed of the Sebastian-Lackner free-vortex wake aerodynamic model coupled to the nonlinear Hodges-Dowell beam equations, which are extended to include the effects of blade profile asymmetry, higher-order torsional effects, and kinetic energy components associated with periodic rigid-body motions of floating platforms. Rigid-body platform motions are also assigned to the aerodynamic model as varying inflow conditions to emulate operational rotor-wake interactions. Careful attention is given to the wake formation within operational states where the ratio of inflow velocity to induced velocity is over 50%. These states are most susceptible to aerodynamic instabilities, and provide a range of states about which a wake stability analysis can be performed. In addition, the stability analysis used for the numerical framework is implemented into a standalone free-vortex wake aerodynamic model. Both aeroelastic and standalone aerodynamic results are compared to evaluate the level of impact that flexible blades have on the wake formation and wake stability.

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

Fluid-structure interaction simulation of floating structures interacting with complex, large-scale ocean waves and atmospheric turbulence with application to floating offshore wind turbines

Science.gov (United States)

Calderer, Antoni; Guo, Xin; Shen, Lian; Sotiropoulos, Fotis

2018-02-01

We develop a numerical method for simulating coupled interactions of complex floating structures with large-scale ocean waves and atmospheric turbulence. We employ an efficient large-scale model to develop offshore wind and wave environmental conditions, which are then incorporated into a high resolution two-phase flow solver with fluid-structure interaction (FSI). The large-scale wind-wave interaction model is based on a two-fluid dynamically-coupled approach that employs a high-order spectral method for simulating the water motion and a viscous solver with undulatory boundaries for the air motion. The two-phase flow FSI solver is based on the level set method and is capable of simulating the coupled dynamic interaction of arbitrarily complex bodies with airflow and waves. The large-scale wave field solver is coupled with the near-field FSI solver with a one-way coupling approach by feeding into the latter waves via a pressure-forcing method combined with the level set method. We validate the model for both simple wave trains and three-dimensional directional waves and compare the results with experimental and theoretical solutions. Finally, we demonstrate the capabilities of the new computational framework by carrying out large-eddy simulation of a floating offshore wind turbine interacting with realistic ocean wind and waves.

Analysis of the Induction and Wake Evolution of an Offshore Floating Wind Turbine

Directory of Open Access Journals (Sweden)

Matthew Lackner

2012-04-01

Full Text Available The degrees-of-freedom associated with offshore floating wind turbines (OFWTs result in a more dynamic flow field. The resulting aerodynamic loads may be significantly influenced by these motions via perturbations in the evolving wake. This is of great interest in terms of OFWT design, placement and simulation. This study presents free vortex wake method (FVM simulations of the NREL 5-MW wind turbine of a variety of platforms, operating in a range of wind speeds synthesized platform motion time series. Motion-induced wake perturbations are observed to affect induction. Transitions between windmill and propeller states are also observed.

A comparison between the dynamics of horizontal and vertical axis offshore floating wind turbines.

Science.gov (United States)

Borg, M; Collu, M

2015-02-28

The need to further exploit offshore wind resources in deeper waters has led to a re-emerging interest in vertical axis wind turbines (VAWTs) for floating foundation applications. However, there has been little effort to systematically compare VAWTs to the more conventional horizontal axis wind turbine (HAWT). This article initiates this comparison based on prime principles, focusing on the turbine aerodynamic forces and their impact on the floating wind turbine static and dynamic responses. VAWTs generate substantially different aerodynamic forces on the support structure, in particular, a potentially lower inclining moment and a substantially higher torque than HAWTs. Considering the static stability requirements, the advantages of a lower inclining moment, a lower wind turbine mass and a lower centre of gravity are illustrated, all of which are exploitable to have a less costly support structure. Floating VAWTs experience increased motion in the frequency range surrounding the turbine [number of blades]×[rotational speed] frequency. For very large VAWTs with slower rotational speeds, this frequency range may significantly overlap with the range of wave excitation forces. Quantitative considerations are undertaken comparing the reference NREL 5 MW HAWT with the NOVA 5 MW VAWT. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Fundamental study on aerodynamic force of floating offshore wind turbine with cyclic pitch mechanism

International Nuclear Information System (INIS)

Li, Qing'an; Kamada, Yasunari; Maeda, Takao; Murata, Junsuke; Iida, Kohei; Okumura, Yuta

2016-01-01

Wind turbines mounted on floating platforms are subjected to completely different and soft foundation properties, rather than onshore wind turbines. Due to the flexibility of their mooring systems, floating offshore wind turbines are susceptible to large oscillations such as aerodynamic force of the wind and hydrodynamic force of the wave, which may compromise their performance and structural stability. This paper focuses on the evaluation of aerodynamic forces depending on suppressing undesired turbine's motion by a rotor thrust control which is controlled by pitch changes with wind tunnel experiments. In this research, the aerodynamic forces of wind turbine are tested at two kinds of pitch control system: steady pitch control and cyclic pitch control. The rotational speed of rotor is controlled by a variable speed generator, which can be measured by the power coefficient. Moment and force acts on model wind turbine are examined by a six-component balance. From cyclic pitch testing, the direction and magnitude of moment can be arbitrarily controlled by cyclic pitch control. Moreover, the fluctuations of thrust coefficient can be controlled by collective pitch control. The results of this analysis will help resolve the fundamental design of suppressing undesired turbine's motion by cyclic pitch control. - Highlights: • Offshore wind offers additional options in regions with low onshore potential. • Two kinds of pitch control system: Steady pitch control and Cyclic pitch control. • Performance curves and unsteady aerodynamics are investigated in wind tunnel. • Fluctuations of thrust coefficient can be controlled by collective pitch control.

Offshore atomic power plants

International Nuclear Information System (INIS)

Anon.

1975-01-01

Various merits of offshore atomic power plants are illustrated, and their systems are assessed. The planning of the offshore atomic power plants in USA is reviewed, and the construction costs of the offshore plant in Japan were estimated. Air pollution problem may be solved by the offshore atomic power plants remarkably. Deep water at low temperature may be advantageously used as cooling water for condensers. Marine resources may be bred by building artificial habitats and by providing spring-up equipments. In the case of floating plants, the plant design can be standardized so that the construction costs may be reduced. The offshore plants can be classified into three systems, namely artificial island system, floating system and sea bottom-based system. The island system may be realized with the present level of civil engineering, but requires the development of technology for the resistance of base against earthquake and its calculation means. The floating system may be constructed with conventional power plant engineering and shipbuilding engineering, but the aseismatic stability of breakwater may be a problem to be solved. Deep water floating system and deep water submerging system are conceivable, but its realization may be difficult. The sea bottom-based system with large caissons can be realized by the present civil engineering, but the construction of the caissons, stability against earthquake and resistance to waves may be problems to be solved. The technical prediction and assessment of new plant sites for nuclear power plants have been reported by Science and Technology Agency in 1974. The construction costs of an offshore plant has been estimated by the Ministry of International Trade and Industry to be yen71,026/kW as of 1985. (Iwakiri, K.)

An experimental study of the effect of mooring systems on the dynamics of a SPAR buoy-type floating offshore wind turbine

Directory of Open Access Journals (Sweden)

Sinpyo Hong

2015-05-01

Full Text Available An experimental study of the effect of mooring systems on the dynamics of a SPAR buoy-type floating offshore wind turbine is presented. The effects of the Center of Gravity (COG, mooring line spring constant, and fair-lead location on the turbine’s motion in response to regular waves are investigated. Experimental results show that for a typical mooring system of a SPAR buoy-type Floating Offshore Wind Turbine (FOWT, the effect of mooring systems on the dynamics of the turbine can be considered negligible. However, the pitch decreases notably as the COG increases. The COG and spring constant of the mooring line have a negligible effect on the fairlead displacement. Numerical simulation and sensitivity analysis show that the wind turbine motion and its sensitivity to changes in the mooring system and COG are very large near resonant frequencies. The test results can be used to validate numerical simulation tools for FOWTs.

An Advanced Control Technique for Floating Offshore Wind Turbines Based on More Compact Barge Platforms

Directory of Open Access Journals (Sweden)

Joannes Olondriz

2018-05-01

Full Text Available Hydrodynamic Floating Offshore Wind Turbine (FOWT platform specifications are typically dominated by seaworthiness and maximum operating platform-pitch angle-related requirements. However, such specifications directly impact the challenge posed by an FOWT in terms of control design. The conventional FOWT systems are typically based on large, heavy floating platforms, which are less likely to suffer from the negative damping effect caused by the excessive coupling between blade-pitch control and platform-pitch motion. An advanced control technique is presented here to increase system stability for barge type platforms. Such a technique mitigates platform-pitch motions and improves the generator speed regulation, while maintaining blade-pitch activity and reducing blade and tower loads. The NREL’s 5MW + ITI Energy barge reference model is taken as a basis for this work. Furthermore, the capabilities of the proposed controller for performing with a more compact and less hydrodynamically stable barge platform is analysed, with encouraging results.

The VolturnUS 1:8 Floating Wind Turbine: Design, Construction, Deployment, Testing, Retrieval, and Inspection of the First Grid-Connected Offshore Wind Turbine in US

Energy Technology Data Exchange (ETDEWEB)

Dagher, Habib [Univ. of Maine, Orono, ME (United States); Viselli, Anthony [Univ. of Maine, Orono, ME (United States); Goupee, Andrew [Univ. of Maine, Orono, ME (United States); Kimball, Richard [Maine Maritime Academy, Castine, ME (United States); Allen, Christopher [Univ. of Maine, Orono, ME (United States)

2017-08-15

Volume II of the Final Report for the DeepCwind Consortium National Research Program funded by US Department of Energy Award Number: DE-EE0003278.001 summarizes the design, construction, deployment, testing, numerical model validation, retrieval, and post-deployment inspection of the VolturnUS 1:8-scale floating wind turbine prototype deployed off Castine, Maine on June 2nd, 2013. The 1:8 scale VolturnUS design served as a de-risking exercise for a commercial multi-MW VolturnUS design. The American Bureau of Shipping Guide for Building and Classing Floating Offshore Wind Turbine Installations was used to design the prototype. The same analysis methods, design methods, construction techniques, deployment methods, mooring, and anchoring planned for full-scale were used. A commercial 20kW grid-connected turbine was used and was the first offshore wind turbine in the US.

Extreme Value Predictions for Wave- and Wind-induced Loads on Floating Offshore Wind Turbines using FORM

DEFF Research Database (Denmark)

Joensen, Sunvard; Jensen, Jørgen Juncher; Mansour, Alaa E.

2007-01-01

duration of the time domain simulations needed (typically 60-300s to cover the hy-drodynamic memory effects in the response) the calcu-lation of the mean out-crossing rates of a given response are very fast. Thus complicated non-linear effects can be included. The FORM analysis also identifies the most...... probable wave episodes leading to given re-sponses. As an example the motions of floating foundations for offshore wind turbines are analysed taking into consid-eration both the wave and wind induced loads and con-sidering different mooring systems. The possible large horizontal motions make it important...

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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.

Comparison of Simulations and Offshore Measurement Data of a Combined Floating Wind and Wave Energy Demonstration Platform

DEFF Research Database (Denmark)

Yde, Anders; Larsen, Torben J.; Hansen, Anders Melchior

2015-01-01

In this paper, results from comparisons of simulations and measured offshore data from a floating combined wind and wave energy conversion system are presented. The numerical model of the platform is based on the aeroelastic code, HAWC2, developed by DTU Wind Energy, which is coupled with a special...... external system that reads the output generated directly by the wave analysis software WAMIT. The main focus of the comparison is on the statistical trends of the platform motion, mooring loads, and turbine loads in measurements and simulations during different operational conditions. Finally, challenges...

Proposing offshore photovoltaic (PV) technology to the energy mix of the Maltese islands

International Nuclear Information System (INIS)

Trapani, Kim; Millar, Dean L.

2013-01-01

Highlights: ► Significant cost and carbon savings for offshore PV integration. ► Maximum savings at circa 315 MW for thin film PV integration. ► Minimum generating capacity of turbines significant in cost of electricity. ► Part-load efficiencies of current system could hugely limit the integration of renewables. - Abstract: The islands of Malta are located in the Mediterranean basin enjoying 5.3 kW h/m 2 /day of solar insolation, at a latitude of 35°50N. Electricity generation for the islands is dependent upon imported fossil fuels for combustion. The available solar resource could be exploited to offset the current generation of electricity using solar photovoltaic technology (PV). Due to the limited land availability onshore, the offshore environment surrounding the Maltese islands were considered for the installation of PV floating on the sea surface. The output from such an installation would have to be integrated with the existing conventional electricity generation infrastructure, which currently relies on gas and steam turbine technology. To assess the feasibility of floating PV being integrated with the existing fossil plant, monthly trend consumption data for Malta were analysed. The change in gasoil and heavy fuel oil (HFO) consumption resulting from the part load efficiency variation and the displacement of electricity generation from the PVs were estimated. A cost analysis was prepared for the system integration analysis specifically accounting for the reduction in combustion of fossil fuels at the power station and the capital expenditures and operating costs due to the floating PV installation. Aside from the basic cost-benefit of a floating PV installation, CO 2 savings are also considered

Offshore code comparison collaboration continuation within IEA Wind Task 30: Phase II results regarding a floating semisubmersible wind system

DEFF Research Database (Denmark)

Robertson, Amy; Jonkman, Jason M.; Vorpahl, Fabian

2014-01-01

Offshore wind turbines are designed and analyzed using comprehensive simulation tools (or codes) that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, mooring dynamics, and founda......Offshore wind turbines are designed and analyzed using comprehensive simulation tools (or codes) that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, mooring dynamics......, and foundation dynamics of the support structure. This paper describes the latest findings of the code-to-code verification activities of the Offshore Code Comparison Collaboration Continuation project, which operates under the International Energy Agency Wind Task 30. In the latest phase of the project......, participants used an assortment of simulation codes to model the coupled dynamic response of a 5-MW wind turbine installed on a floating semisubmersible in 200 m of water. Code predictions were compared from load case simulations selected to test different model features. The comparisons have resulted...

On the fundamental performance of the floating offshore wave power device (FOWAD)

International Nuclear Information System (INIS)

Hotta, H.; Washio, Y.; Miyazaki, T.

1990-01-01

This paper reports on the wave power absorption, wave dissipation, mooring line tension and oscillation in regular and irregular (long created and short created) waves of the floating offshore wave power device (FOWAD) that were measured and analyzed by a scale model test in a wave tank. FOWAD is an oscillating water column type device equipped with air turbine generators, and air chambers facing the waves. Therefore, it belongs in the close of terminator type wave power devices. It has several projecting walls in front of each air chamber, several buoyancy compartments behind each chamber and stabilizer at the keel. The measured data indicates that, the performance and stability were improved in comparison with former terminator type devices, FOWAD absorbed about 30% of wave power and mooring line tension was within the limits of safety even in rough seas. Nevertheless the performance for dissipation of waves can be improved. This paper describes on the results of the model test and subsequent analysis

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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.

A study of rotor and platform design trade-offs for large-scale floating vertical axis wind turbines

Science.gov (United States)

Griffith, D. Todd; Paquette, Joshua; Barone, Matthew; Goupee, Andrew J.; Fowler, Matthew J.; Bull, Diana; Owens, Brian

2016-09-01

Vertical axis wind turbines are receiving significant attention for offshore siting. In general, offshore wind offers proximity to large populations centers, a vast & more consistent wind resource, and a scale-up opportunity, to name a few beneficial characteristics. On the other hand, offshore wind suffers from high levelized cost of energy (LCOE) and in particular high balance of system (BoS) costs owing to accessibility challenges and limited project experience. To address these challenges associated with offshore wind, Sandia National Laboratories is researching large-scale (MW class) offshore floating vertical axis wind turbines (VAWTs). The motivation for this work is that floating VAWTs are a potential transformative technology solution to reduce offshore wind LCOE in deep-water locations. This paper explores performance and cost trade-offs within the design space for floating VAWTs between the configurations for the rotor and platform.

On the relative importance of loads acting on a floating vertical axis wind turbine system when evaluating the global system response

DEFF Research Database (Denmark)

Collu, Maurizio; Borg, Michael; Manuel, Lance

2016-01-01

Interest in offshore floating wind turbines has been growing over the last decade. While a number of studies have been conducted to model the dynamics of offshore floating HAWT systems (e.g. OC3-Phase IV, OC4-Phase II), relatively few studies have been conducted on floating VAWT systems, despite...... offshore floating VAWT, considering a turbulent wind field and stochastically generated waves, to assess the more critical loads and distinguish them from those with negligible effect, when estimating the global system response. The floating VAWT system considered is comprised of a 5MW rotor supported...

Large floating structures technological advances

CERN Document Server

Wang, BT

2015-01-01

This book surveys key projects that have seen the construction of large floating structures or have attained detailed conceptual designs. This compilation of key floating structures in a single volume captures the innovative features that mark the technological advances made in this field of engineering, and will provide a useful reference for ideas, analysis, design, and construction of these unique and emerging urban projects to offshore and marine engineers, urban planners, architects and students.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

Science.gov (United States)

Sant, T.; Buhagiar, D.; Farrugia, R. N.

2014-06-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

International Nuclear Information System (INIS)

Sant, T; Buhagiar, D; Farrugia, R N

2014-01-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

Preliminary Design of a Multi-Column TLP Foundation for a 5-MW Offshore Wind Turbine

OpenAIRE

Yongsheng Zhao; Jianmin Yang; Yanping He

2012-01-01

Currently, floating wind turbines (FWTs) may be the more economical and suitable systems with which to exploit offshore wind energy in deep waters. Among the various types of floating foundations for offshore wind farms, a tension leg platform (TLP) foundation can provide a relatively stable platform for currently available offshore wind turbines without requiring major modifications. In this study, a new multi-column TLP foundation (WindStar TLP) was developed for the NREL 5-MW offshore wind...

Lake Michigan Offshore Wind Feasibility Assessment

Energy Technology Data Exchange (ETDEWEB)

Boezaart, Arnold [GVSU; Edmonson, James [GVSU; Standridge, Charles [GVSU; Pervez, Nahid [GVSU; Desai, Neel [University of Michigan; Williams, Bruce [University of Delaware; Clark, Aaron [GVSU; Zeitler, David [GVSU; Kendall, Scott [GVSU; Biddanda, Bopi [GVSU; Steinman, Alan [GVSU; Klatt, Brian [Michigan State University; Gehring, J. L. [Michigan State University; Walter, K. [Michigan State University; Nordman, Erik E. [GVSU

2014-06-30

The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

The typhoon effect on the aerodynamic performance of a floating offshore wind turbine

Directory of Open Access Journals (Sweden)

Zhe Ma

2017-12-01

Full Text Available The wind energy resource is considerably rich in the deep water of China South Sea, where wind farms have to face the challenge of extreme typhoon events. In this work, the typhoon effect on the aerodynamic performance of the 5MW OC3-Hywind floating offshore wind turbine (FOWT system has been investigated, based on the Aero-Hydro-Servo-Elastic FAST code. First, considering the full field observation data of typhoon “Damrey” is a long duration process with significant turbulence and high wind speed, so one 3-h representative truncated typhoon wind speed time history has been selected. Second, the effects of both the (variable-speed and collective-pitch control system of NREL 5 MW wind turbine and the motion of the floating platform on the blade aerodynamic performance of the FOWT system during the representative typhoon time history has been investigated, based on blade element momentum (BEM theory (coupled with potential theory for the calculation of the hydrodynamic loads of the Spar platform. Finally, the effects of different wind turbine control strategies, control parameter (KP–KI combinations, wave heights and parked modes on the rotor aerodynamic responses of the FOWT system have been clarified. The extreme typhoon event can result in considerably large extreme responses of the rotor thrust and the generated power due to the possible blade pitch angle error phenomenon. One active-parked strategy has been proposed for reducing the maximum aerodynamic responses of the FOWT system during extreme typhoon events.

Comparison of simulations and offshore measurement data of a prototype of a floating combined wind and wave energy conversion system

DEFF Research Database (Denmark)

Yde, Anders; Larsen, Torben J.; Hansen, Anders Melchior

2015-01-01

In this paper, results from comparisons of simulations and measured offshore data from a floating combined wind and wave energy conversion system are presented. The device is a downscaled prototype that consists of a floating platform equipped with ten wave energy absorbers and three wind turbines....... The numerical model of the platform is based on the aeroelastic code, HAWC2, developed by DTU Wind Energy, which is coupled with a special external system that reads the output generated directly by the wave analysis software, WAMIT. The model also includes models for the dynamic mooring lines as well...... as the turbines non-linear yaw and teeter motion behavior. The main focus on the comparison will be on the statistical trends of the platform motion, mooring loads and turbine loads in measurements and simulations during different operational conditions such as increasing wind speed, wave height and wind...

Fresh water generators onboard a floating platform

International Nuclear Information System (INIS)

Tewari, P.K.; Verma, R.K.; Misra, B.M.; Sadhulkan, H.K.

1997-01-01

A dependable supply of fresh water is essential for any ocean going vessel. The operating and maintenance personnel on offshore platforms and marine structures also require a constant and regular supply of fresh water to meet their essential daily needs. A seawater thermal desalination unit onboard delivers good quality fresh water from seawater. The desalination units developed by Bhabha Atomic Research Centre (BARC) suitable for ocean going vessels and offshore platforms have been discussed. Design considerations of such units with reference to floating platforms and corrosive environments have been presented. The feasibility of coupling a low temperature vacuum evaporation (LTVE) desalination plant suitable for an onboard floating platform to a PHWR nuclear power plant has also been discussed. (author). 1 ref., 3 figs, 2 tabs

Offshore concrete structures; Estructuras Offshore (mar adentro) de Hormigon

Energy Technology Data Exchange (ETDEWEB)

Lamas Pardo, M.; Carral Couce, L. M.

2011-07-01

proof that in certain cases the benefits to the steel tip the lance toward the concrete. concrete Gravity Baseplaforms type Con deep have been building since the first unit became operational in 1976, together with a few floating platforms, that in its geometry are similar to those made of steel (barges, semi-submersibles and TLP type platforms). Some of the concepts in concrete that are being emerging last years are floating and gravity base platforms for use as offshore LNG terminals and as offshore industrial plants. The life of these barges can be designed up to 200 years, as the floating Nkossabarge, so they con be a good alternative to the construction of these facilities an land, thus avoiding landfills on the coast that degrade the already punished coast in industrialized countries. the challenge is precisely to optimize their capital costs to complete for an offshore installation against a shore facility. The environment will undoubtedly benefit from this great challenge that lies ahead in the XXI century. (Author) 29 refs.

System evaluation of offshore platforms with gas liquefaction processes

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; de Oliveira Júnior, Silvio

2018-01-01

Abstract Floating, production, storage and offloading plants are facilities used for offshore processing of hydrocarbons in remote locations. At present, the produced gas is injected back into the reservoir instead of being exported. The implementation of refrigeration processes offshore for liqu......Abstract Floating, production, storage and offloading plants are facilities used for offshore processing of hydrocarbons in remote locations. At present, the produced gas is injected back into the reservoir instead of being exported. The implementation of refrigeration processes offshore...... improvements are discussed based on an energy and exergy analysis. Compared to a standard platform where gas is directly injected into the reservoir, the total power consumption increases by up to 50%, and the exergy destruction within the processing plant doubles when a liquefaction system is installed....... It is therefore essential to conduct a careful analysis of the trade-off between the capital costs and operating revenues for such options....

Wind-wave induced dynamic response analysis for motions and mooring loads of a spar-type offshore floating wind turbine

Institute of Scientific and Technical Information of China (English)

马钰; 肖龙飞; 胡志强

2014-01-01

Due to the energy crisis and the environmental issues like pollution and global warming, the exploration for renewable and clean energies becomes crucial. The offshore floating wind turbines (OFWTs) draw a great deal of attention recently as a means to exploit the steadier and stronger wind resources available in deep water seas. This paper studies the hydrodynamic characteristics of a spar-type wind turbine known as the OC3-Hywind concept and the dynamic responses of the turbine. Response characteristics of motions and mooring loads of the system under different sea states are evaluated and the effects of the loads induced by the wind and the wave on the system are discussed. The calculations are carried out with the numerical simulation code FAST in the time domain and the frequency analysis is made by using the FFT method. The results and the conclusions from this paper might help better understand the behavior characteristics of the floating wind turbine system under actual ocean environments and provide valuable data in design and engineering practice.

A green energy for a blue growth: offshore wind energy. Proposals by France Energie Eolienne for the development of a competitive and job-creating offshore wind energy sector

International Nuclear Information System (INIS)

2013-06-01

This report outlines the significant and efficient contribution of wind energy to the energy mix, highlights the high potential of offshore wind energy for France, and stresses the need of an ambitious programme as a sine qua non condition for the development of this sector. It also makes ten proposals for this development. It describes how to specify ambitious objectives for offshore wind turbines (grounded or floating) in compliance with the French potential and the European market. It analyses means to reach an ambitious objective of 15 GW of grounded offshore wind energy and 6 GW of floating offshore wind energy by 2030. It discusses how benefits can be drawn from such a development for the community and future generations

Dynamic modeling of a spar-type floating offshore wind turbine

NARCIS (Netherlands)

Savenije, L.B.; Ashuri, T.; Van Bussel, G.J.W.; Staerdahl, J.W.

2010-01-01

The installation of floating wind farms in deeper water is encouraged by the stronger and steadier wind, the lower visibility and noise impact, the absence of road restrictions, but also the absence or shortage of shallow water. In the summer of 2009, the first large-scale floating wind turbine

Offshore wind power: does France remain ashore?

International Nuclear Information System (INIS)

Bongrain, T.

2015-01-01

France benefits from favorable geographical conditions for offshore wind power but the development of a dedicated industrial sector is slow. 6 projects of wind power farms where turbines are rooted in the seabed are expected to operate progressively from 2018, they represent a cumulated power capacity of 2920 MW. A call for projects has been launched by French authorities for floating offshore wind farms off Brittany and in the mediterranean sea but it will not be sufficient to help to fulfill the declared goal of 40% of the electricity produced in France should be of renewable origin. The main weakness is the cost and countries like Germany benefit from the shallow waters of the North sea to install wind farms at lower costs. The solution could be the development in France of an industrial sector dedicated to floating wind turbines that are easier to install in deep water and can be settled farther off the coast to meet the demand of environmentalists for seascape preservation. More sites could become available for floating wind turbines than for seabed-rooted ones and as the consequence the market for floating systems may become more important. (A.C.)

A Comparison on the Dynamics of a Floating Vertical Axis Wind Turbine on Three Different Floating Support Structures

OpenAIRE

Borg, Michael; Collu, Maurizio

2014-01-01

To increase the competitiveness of offshore wind energy in the global energy market, it is necessary to identify optimal offshore wind turbine configurations to deliver the lowest cost of energy. For deep waters where floating wind turbines are the feasible support structure option, the vertical axis wind turbine concept might prove to be one of these optimal configurations. This paper carries out a preliminary investigation into the dynamics of a vertical axis wind turbine coupled with three...

Offshore concrete structures

International Nuclear Information System (INIS)

Lamas Pardo, M.; Carral Couce, L. M.

2011-01-01

proof that in certain cases the benefits to the steel tip the lance toward the concrete. concrete Gravity Baseplaforms type Con deep have been building since the first unit became operational in 1976, together with a few floating platforms, that in its geometry are similar to those made of steel (barges, semi-submersibles and TLP type platforms). Some of the concepts in concrete that are being emerging last years are floating and gravity base platforms for use as offshore LNG terminals and as offshore industrial plants. The life of these barges can be designed up to 200 years, as the floating Nkossabarge, so they con be a good alternative to the construction of these facilities an land, thus avoiding landfills on the coast that degrade the already punished coast in industrialized countries. the challenge is precisely to optimize their capital costs to complete for an offshore installation against a shore facility. The environment will undoubtedly benefit from this great challenge that lies ahead in the XXI century. (Author) 29 refs.

Design off-shore wind climate

Energy Technology Data Exchange (ETDEWEB)

Larsen, G C; Joergensen, H E [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

1999-03-01

Specific recommendations of off-shore turbulence intensities, applicable for design purposes, are lacking in the present IEC-code. The present off-shore wind climate analysis presents the distribution of the turbulence standard deviation around the mean turbulence standard deviation, conditioned on the mean wind speed. Measured distributions, based on a huge amount of measuring data from two shallow water off-shore sites, are parameterized by fitting to a three parameter Weibull distribution. Combining a simple heuristic load model with the parameterized probability density functions of the turbulence standard deviations, an empirical off-shore design turbulence intensity is evaluated that in average yields the same fatigue damage as the distributed turbulence intensity. The proposed off-shore design turbulence intensity is, within the IEC code framework, applicable for extreme as well as for fatigue load determination. (au)

Floating offshore wind turbines for shallow waters

NARCIS (Netherlands)

Bulder, B.H.; Henderson, A.; Huijsmans, R.H.M.; Peeringa, J.M.; Pierik, J.T.G.; Snijders, E.J.B.; Hees, M.Th. van; Wijnants, G.H.; Wolf, M.J.

2003-01-01

Bottom mounted Offshore wind turbines seem to have a promising future but they are restricted to shallow waters of Northern Europe. Many projects are planned or are in the phase of construction on the North Sea and the Baltic Sea. All projects that are planned have a water depth up to approximately

Offshore wind power in Finland

Energy Technology Data Exchange (ETDEWEB)

Holttinen, H. [VTT Energy, Espoo (Finland)

1998-12-31

The objectives of the project were to estimate the technical offshore wind power potential of the Gulf of Bothnia, with cost assessments, to study icing conditions and ice loads, and to design a foundation suitable for the environmental conditions. The technical offshore potential from Vaasa to Tornio is huge, more than 40 TWh/a, although the cost of offshore wind power is still higher than on land. Wind turbines have not previously been designed for the icing conditions found in Gulf of Bothnia and the recommendations for load cases and siting of megawatt-class turbines are an important result of the project. (orig.)

Floating axis wind turbines for offshore power generation—a conceptual study

International Nuclear Information System (INIS)

Akimoto, Hiromichi; Tanaka, Kenji; Uzawa, Kiyoshi

2011-01-01

The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

Cooperative control system of the floating cranes for the dual lifting

OpenAIRE

Mihee Nam; Jinbeom Kim; Jaechang Lee; Daekyung Kim; Donghyuk Lee; Jangmyung Lee

2018-01-01

This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes ...

Vertical Dynamic Stiffness of Offshore Foundations

DEFF Research Database (Denmark)

Latini, Chiara; Cisternino, Michele; Zania, Varvara

2016-01-01

Nowadays, pile and suction caisson foundations are widely used to support offshore structures which are subjected to vertical dynamic loads. The dynamic soil-structure interaction of floating foundations (foundations embedded in a soil layer whose height is greater than the foundation length) is ...

SOFIA - A simulation tool for bottom founded and floating offshore structures

DEFF Research Database (Denmark)

Nielsen, Morten Eggert; Ulriksen, Martin Dalgaard; Damkilde, Lars

2017-01-01

This paper presents a recently developed simulation tool, SOFIA (Simulation Of Floaters In Action), suitable for modeling slender bottom founded and moored/freely floating space frame structures exposed to environmental loads. In contrast to traditional rigid body formulations of floating...... and structure domains, which are coupled through the structural equation of motion. The structural domain is handled by means of the finite element method, while large displacements and stress stiffening effects, exhibited by moored floating structures, are inherently included due to a co-rotational element...... formulation. The fluid domain is modeled by an appropriate water wave theory, and the hydrodynamic loads are evaluated at the instantaneous fluid-structure interface by means of a relative Morison equation. The equation of motion is solved in time domain, which makes SOFIA capable of handling bottom founded...

Determination of current loads of floating platform for special purposes

Science.gov (United States)

Ma, Guang-ying; Yao, Yun-long; Zhao, Chen-yao

2017-08-01

This article studied a new floating offshore platform for special purposes, which was assembled by standard floating modules. The environmental load calculation of the platform is an important part of the research of the ocean platform, which has always been paid attention to by engineers. In addition to wave loads, the wind loads and current loads are also important environmental factors that affect the dynamic response of the offshore platform. The current loads on the bottom structure should not be ignored. By Fluent software, the hydrostatic conditions and external current loads of the platform were calculated in this paper. The coefficient which is independent of the current velocity, namely, current force coefficient, can be fitted through current loads, which can be used for the consequent hydrodynamic and mooring analyses.

Offshore wind power. Market opportunities for the Norwegian supply industry, and regulatory framework needed to realize these opportunities

Energy Technology Data Exchange (ETDEWEB)

Volden, G.; Bull-Berg, H.; Skjeret, F.; Finne, H.; Hofmann, M.

2010-07-01

Full text: Offshore wind power has received much attention these last few years, from governments, NGOs as well as energy companies. There are still huge technological challenges to overcome, especially concerning floating constructions on deep water, but offshore wind has a potential to become an important energy source in the future. The main objective of our study was to build more knowledge about market opportunities for the Norwegian supply industry, most of which is closely related to offshore oil and gas activities. We started by mapping and quantifying the parts of the supply industry that could be relevant to offshore wind, which is actually most of it. Then, through interviews and questionnaires, we asked potential suppliers about their attitude and strategies towards offshore wind. An over-whelming majority was optimistic about future markets internationally, whereas there was less belief in large-scale power production on the Norwegian shelf. Suppliers do not necessarily find the lack of a Norwegian 'home market' to be a barrier. However many of them expressed that the risk is high and it may be crucial to establish a national demo program, for supplier to test new technological solutions at low cost, gain references and develop industrial relations with other suppliers. We argue that being part of an industrial cluster may be a success criterion within offshore wind. By using Michael Porter's 'Diamond Model' we analyse Norway's inherent competitiveness as a potential host for an offshore wind cluster - with or without energy producers. Norway's most important advantage is the existing industrial environment, with a strong maritime sector and engineering companies with special competence in floating and fixed installations for the oil industry. Norway also has disadvantages; such as lack of traditions within wind power and wind turbine manufacturing, as well as high salaries and lack of engineers. So far it is also

Application of a Monte Carlo procedure for probabilistic fatigue design of floating offshore wind turbines

Directory of Open Access Journals (Sweden)

K. Müller

2018-03-01

Full Text Available Fatigue load assessment of floating offshore wind turbines poses new challenges on the feasibility of numerical procedures. Due to the increased sensitivity of the considered system with respect to the environmental conditions from wind and ocean, the application of common procedures used for fixed-bottom structures results in either inaccurate simulation results or hard-to-quantify conservatism in the system design. Monte Carlo-based sampling procedures provide a more realistic approach to deal with the large variation in the environmental conditions, although basic randomization has shown slow convergence. Specialized sampling methods allow efficient coverage of the complete design space, resulting in faster convergence and hence a reduced number of required simulations. In this study, a quasi-random sampling approach based on Sobol sequences is applied to select representative events for the determination of the lifetime damage. This is calculated applying Monte Carlo integration, using subsets of a resulting total of 16 200 coupled time–domain simulations performed with the simulation code FAST. The considered system is the Danmarks Tekniske Universitet (DTU 10 MW reference turbine installed on the LIFES50+ OO-Star Wind Floater Semi 10 MW floating platform. Statistical properties of the considered environmental parameters (i.e., wind speed, wave height and wave period are determined based on the measurement data from the Gulf of Maine, USA. Convergence analyses show that it is sufficient to perform around 200 simulations in order to reach less than 10 % uncertainty of lifetime fatigue damage-equivalent loading. Complementary in-depth investigation is performed, focusing on the load sensitivity and the impact of outliers (i.e., values far away from the mean. Recommendations for the implementation of the proposed methodology in the design process are also provided.

Numerical study on aerodynamic damping of floating vertical axis wind turbines

DEFF Research Database (Denmark)

Cheng, Zhengshun; Aagaard Madsen, Helge; Gao, Zhen

2016-01-01

Harvesting offshore wind energy resources using floating vertical axis wind turbines (VAWTs) has attracted an increasing interest in recent years. Due to its potential impact on fatigue damage, the aerodynamic damping should be considered in the preliminary design of a floating VAWT based...... on the frequency domain method. However, currently the study on aerodynamic damping of floating VAWTs is very limited. Due to the essential difference in aerodynamic load characteristics, the aerodynamic damping of a floating VAWT could be different from that of a floating horizontal axis wind turbine (HAWT...... to four were considered. The aerodynamic damping under steady and turbulent wind conditions were estimated using fully coupled aero-hydro-servo-elastic time domain simulations. It is found that the aerodynamic damping ratio of the considered floating VAWTs ranges from 1.8% to 5.3%. Moreover...

Numerical investigation of interactions between marine atmospheric boundary layer and offshore wind farm

Science.gov (United States)

Lyu, Pin; Chen, Wenli; Li, Hui; Shen, Lian

2017-11-01

In recent studies, Yang, Meneveau & Shen (Physics of Fluids, 2014; Renewable Energy, 2014) developed a hybrid numerical framework for simulation of offshore wind farm. The framework consists of simulation of nonlinear surface waves using a high-order spectral method, large-eddy simulation of wind turbulence on a wave-surface-fitted curvilinear grid, and an actuator disk model for wind turbines. In the present study, several more precise wind turbine models, including the actuator line model, actuator disk model with rotation, and nacelle model, are introduced into the computation. Besides offshore wind turbines on fixed piles, the new computational framework has the capability to investigate the interaction among wind, waves, and floating wind turbines. In this study, onshore, offshore fixed pile, and offshore floating wind farms are compared in terms of flow field statistics and wind turbine power extraction rate. The authors gratefully acknowledge financial support from China Scholarship Council (No. 201606120186) and the Institute on the Environment of University of Minnesota.

1:50 Scale Testing of Three Floating Wind Turbines at MARIN and Numerical Model Validation Against Test Data

Energy Technology Data Exchange (ETDEWEB)

Dagher, Habib [Univ. of Maine, Orno, ME (United States); Viselli, Anthony [Univ. of Maine, Orno, ME (United States); Goupee, Andrew [Univ. of Maine, Orno, ME (United States); Allen, Christopher [Univ. of Maine, Orno, ME (United States)

2017-08-15

The primary goal of the basin model test program discussed herein is to properly scale and accurately capture physical data of the rigid body motions, accelerations and loads for different floating wind turbine platform technologies. The intended use for this data is for performing comparisons with predictions from various aero-hydro-servo-elastic floating wind turbine simulators for calibration and validation. Of particular interest is validating the floating offshore wind turbine simulation capabilities of NREL’s FAST open-source simulation tool. Once the validation process is complete, coupled simulators such as FAST can be used with a much greater degree of confidence in design processes for commercial development of floating offshore wind turbines. The test program subsequently described in this report was performed at MARIN (Maritime Research Institute Netherlands) in Wageningen, the Netherlands. The models considered consisted of the horizontal axis, NREL 5 MW Reference Wind Turbine (Jonkman et al., 2009) with a flexible tower affixed atop three distinct platforms: a tension leg platform (TLP), a spar-buoy modeled after the OC3 Hywind (Jonkman, 2010) and a semi-submersible. The three generic platform designs were intended to cover the spectrum of currently investigated concepts, each based on proven floating offshore structure technology. The models were tested under Froude scale wind and wave loads. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine which exhibits negligible swirl and low turbulence intensity in the flow field. Recorded data from the floating wind turbine models included rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions and accelerations at key locations on the nacelle, tower, and platform. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with

Model Development and Loads Analysis of an Offshore Wind Turbine on a Tension Leg Platform with a Comparison to Other Floating Turbine Concepts: April 2009

Energy Technology Data Exchange (ETDEWEB)

Matha, D.

2010-02-01

This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. The report also provides a description of the development process of the TLP model. The model has been verified via comparisons to frequency-domain calculations. Important differences have been identified between the frequency-domain and time-domain simulations, and have generated implications for the conceptual design process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the IEC 61400-3 offshore wind turbine design standard was performed with the verified TLP model. This report compares the loads for the wind turbine on the TLP to those of an equivalent land-based turbine. Major instabilities for the TLP are identified and described.

Position control of a floating nuclear power plant

International Nuclear Information System (INIS)

Motohashi, K.; Hamamoto, T.; Sasaki, R.; Kojima, M.

1993-01-01

In spite of the increasing demand of electricity in Japan, the sites of nuclear power plants suitable for conventional seismic regulations become severely limited. Under these circumstances, several types of advanced siting technology have been developed. Among them, floating power plants have a great advantage of seismic isolation that leads to the seismic design standardization and factory fabrication. The feasibility studies or preliminary designs of floating power plants enclosed by breakwaters in the shallow sea have been carried out last two decades in U.S. and Japan. On the other hand, there are few investigations on the dynamic behavior of floating power plants in the deep sea. The offshore floating nuclear power plants have an additional advantage in that large breakwaters are not required, although the safety checking is inevitable against wind-induced waves. The tension-leg platforms which have been constructed for oil drilling in the deep sea seem to be a promising offshore siting technology of nuclear power plants. The tension-leg mooring system can considerably restrain the heave and pitch of a floating power plant because of significant stiffness in the vertical direction. Different from seismic effects, wind-induced waves may be predicted in advance by making use of ocean weather forecasts using artificial satellites. According to the wave prediction, the position of the floating plant may be controlled by adjusting the water content in ballast tanks and the length of tension-legs before the expected load arrives. The position control system can reduce the wave force acting on the plant and to avoid the unfavorable response behavior of the plant. In this study a semi-submerged circular cylinder with tension-legs is considered as a mathematical model. The configuration of circular cylinder is effective because the dynamic behavior does not depend on incident wave directions. It is also unique in that it can obtain the closed-form solution of

78 FR 26341 - Aguirre Offshore GasPort, LLC; Notice of Application

Science.gov (United States)

2013-05-06

... LNG terminal, the Aguirre Offshore GasPort Project will include a non-jurisdictional Energy Bridge Regasification Vessel functioning as the floating storage and regasification unit for the Project. The project...

Wave Simulation in Truncated Domains for Offshore Applications

NARCIS (Netherlands)

Wellens, P.R.

2012-01-01

There is a desire to assess extreme wave loads on offshore structures like Floating Production, Storage and Offloading (FPSO) vessels, either for design, or for evaluation when circumstances near the structure change. Design formulae for extreme wave loads are scarce and

Cooperative control system of the floating cranes for the dual lifting

Directory of Open Access Journals (Sweden)

Mihee Nam

2018-01-01

Full Text Available This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

Second wind in the offshore wind industry

International Nuclear Information System (INIS)

Philippe, Edouard; Neyme, Eric; Deboos, Christophe; Villageois, Jean-Remy; Gouverneur, Philippe; Gerard, Bernard; Fournier, Eric; Petrus, Raymond; Lemarquis, David; Dener, Marc; Bivaud, Jean-Pierre; Lemaire, Etienne; Nielsen, Steffen; Lafon, Xavier; Lagandre, Pierre; Nadai, Alain; Pinot de Villechenon, Edouard; Westhues, Markus; Herpers, Frederick; Bisiaux, Christophe; Sperlich, Miriam; Bales, Vincent; Vandenbroeck, Jan; His, Stephane; Derrey, Thierry; Barakat, Georges; Dakyo, Brayima; Carme, Laurent; Petit, Frederic; Ytournel, Sophie; Westhues, Markus; Diller, Armin; Premont, Antoine de; Ruer, Jacques; Lanoe, Frederic; Declercq, Jan; Holmager, Morten; Fidelin, Daniel; Guillet, Jerome; Dudziak, Gregory; Lapierre, Anne; Couturier, Ludovic; Audineau, Jean-Pierre; Rouaix, Eric; De Roeck, Yann-Herve; Quesnel, Louis; Duguet, Benjamin

2011-06-01

After several keynote addresses, this publication contains contributions and Power Point presentations proposed during this conference on the development of offshore wind energy. The successive sessions addressed the following issues: the offshore mass production of electricity (examples of Denmark and Belgium, laying and protecting offshore cables), the space, economic and environmental planning (the Danish experience, the role of the Coastal area integrated management, importance of the public debate, so on), the logistics of port infrastructures (simulation tools, example of Bremerhaven, issues related to project management), innovation at the core of industrial strategies (high power wind turbines, the 6 MW Alstom turbine, chain value and innovation in offshore wind energy, the Vertiwing innovating project of a floating wind turbine, a bench test in Charleston, foundations, gravity base structures, the British experience, the Danish experience), the economic and organisational conditions for development, the validation and certification of technologies

Safety evaluation report in the matter of Offshore Power Systems Floating Nuclear Plants (1-8). Docket No. STN 50-437

International Nuclear Information System (INIS)

1980-02-01

The staff has performed an evaluation of a refractory sacrificial bed, called a core ladle, proposed by Offshore Power Systems (OPS) to be installed in Floating Nuclear Plants (FNPs) to delay the melt-through penetration of molten core debris in the unlikely event of a core meltdown accident. The core ladle design as proposed by OPS is in response to the staff's manufacturing license Condition 4 given in the Final Environmental Statement, Part III, NUREG-0502, dated December 1978 (FES-III). This condition requires that a pad constructed of magnesium oxide, or other equivalent refractory material, be installed in the FNP structure within the lower reactor cavity. The material must provide increased resistance to melt-through by the molten reactor core, must not react with core debris to form a large volume of gases, and must not have any deleterious effects on safety

Floating wind generators offshore wind farm: Implications for structural loads and control actions

International Nuclear Information System (INIS)

Garcia, E.; Morant F, Quiles E.; Correcher, A.

2009-01-01

This paper describes the work currently carried out in the design of floating wind generators and their involvement in the future development of power generation in marine farms in depths exceeding 20 m. We discuss the main issues to be taken into account in the design of floating platforms, including the involvement of structural loads they bear. Also from a standpoint of control engineering are discussed strategies to reduce structural loads such a system to ensure adequate durability and therefore ensuring their economic viability. Finally, the abstract modeling tools for floating wind turbines that can be used in both structural design and the design of appropriate control algorithms

Final environmental statement. Final addendum to Part II: Manufacture of floating nuclear power plants by Offshore Power Systems. DOCKET-STN--50-437

International Nuclear Information System (INIS)

1978-06-01

This Addendum to Part II of the Final Environmental Statement related to manufacture of floating nuclear power plants by Offshore Power Systems (OPS), NUREG-0056, issued September 1976, was prepared by the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Reactor Regulation. The staff's basic evaluation is presented in NUREG-0056. The current Addendum provides further consideration of a number of topics discussed in NUREG-0056, particularly additional consideration of shore zone siting at estuarine and ocean regions. This Summary and Conclusions recapitulates and is cumulative for Part II of the FES and the current Addendum. Augmentations to the Summary and Conclusions presented in Part II of the FES and arising from the evaluations contained in this Addendum are italicized

Final environmental statement related to the proposed manufacture of floating nuclear power plants by Offshore Power Systems: (Docket No. STN 50-437): Part 2, A generic environmental statement considering the siting and operation of floating nuclear power plants

International Nuclear Information System (INIS)

1976-09-01

The proposed action is the issuance of a manufacturing license to Offshore Power Systems for the startup and operation of a proposed manufacturing facility located at Blount Island, Jacksonville, Florida (Docket No. STN 50-437). No nuclear fuel will be handled or stored at the manufacturing site. The plants will be fueled after they have been towed to and moored within protected basins at specific locations designated by the purchaser and after an operating license has been issued by the Nuclear Regulatory Commission. Each nuclear generating plant, mounted on a floating platform, has a net capacity of 1150 MWe. This energy is provided by a pressurized water reactor steam supply system consisting of a Westinghouse four-loop 3425-MWt unit with an ice-condenser containment system. When one or more of these units is located within a single breakwater, the installation is designated an offshore power station. Volume 2 contains the siting criteria, regulations, effects of construction, effects of operation, and a safety analysis. 2 figs., 2 tabs

Panorama 2013 - Offshore wind power

International Nuclear Information System (INIS)

Vinot, Simon

2012-10-01

While onshore wind power is already a well-developed global industry, offshore wind power is still in the consolidation and globalization phase. The most mature of marine renewable energies is beginning to venture off the European coast and even to other continents, driven by public policies and the ever increasing number of players joining this promising market, which should evolve into deeper waters thanks to floating structures. (author)

Conceptual Design of a Floating Support Structure and Mooring System for a Vertical Axis Wind Turbine

DEFF Research Database (Denmark)

Berthelsen, Petter Andreas; Fylling, Ivar; Vita, Luca

2012-01-01

This paper deals with the conceptual design of a floating support structure and mooring system for a 5MW vertical axis offshore wind turbine. The work is carried out as part of the DeepWind project, where the main objective is to investigate the feasibility of a floating vertical axis offshore wind...... turbine. The DeepWind concept consists of a Darrieus rotor mounted on a spar buoy support structure. The conceptual design is carried out in an iterative process, involving the different subcomponents. The present work is part of the first design iteration and the objective is to find a feasible floating...... support structure and mooring system for the DeepWind concept. The conceptual design is formulated as an optimization problem: Starting with an initial configuration, the optimization procedure tries to find a cheaper solution while satisfying a set of design requirements. This approach utilizes available...

Potential for Jobs and Economic Development from Offshore Wind in California

Energy Technology Data Exchange (ETDEWEB)

Tegen, Suzanne

2016-11-02

In California's future scenarios, energy demand increases with population growth and productivity. Decision-makers will have to make choices about which energy resources to utilize, and offshore wind offers one option for carbon-free electricity with the potential for increased local jobs. This presentation discusses results from an NREL report, Floating Offshore Wind in California: Gross Potential for Jobs and Economic Impacts from Two Future Scenarios. Presenter Suzanne Tegen describes the Jobs and Economic Development Impact (JEDI) model and its results for two offshore wind scenarios in California. She discusses different assumptions and how they affect the scenarios.

Optimal Control of a Ballast-Stabilized Floating Wind Turbine

DEFF Research Database (Denmark)

Christiansen, Søren; Knudsen, Torben; Bak, Thomas

2011-01-01

Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. The use of floating structures for deeper waters is being explored. The control objective is a tradeoff between power capture and fatigue, especially that produced by the oscillations caused by the reduced...... structural stiffness of a floating installation in combination with a coupling between the fore–aft motion of the tower and the blade pitch. To address this problem, the present paper models a ballast-stabilized floating wind turbine, and suggests a linear quadratic regulator (LQR) in combination with a wind...... estimator and a state observer. The results are simulated using aero elastic code and analysed in terms of damage equivalent loads. When compared to a baseline controller, this controller clearly demonstrates better generator speed and power tracking while reducing fatigue loads....

Fuel flexibility in power generation onboard offshore floating units

Energy Technology Data Exchange (ETDEWEB)

Keep, Jeroen van [Waertsilae Corporation, Helsinki (Finland)

2012-07-01

Power Plants for offshore oil and gas installations utilizing dual fuel (DF) reciprocating engines are by many owners seen as an interesting alternative to conventional solutions due to the apparent advantages in fuel flexibility, fuel efficiency and lower emission. The paper summarizes the dual fuel technology, typical solutions for FPSO's and operational. Items that are discussed: DF operation and how it works; fuel flexibility, including transfer between fuel modes; fuel efficiency, also in production an important cost saver; emissions of the different fuel modes; size and weights, constraints; experiences of the P-63 project. With the above it is safe to conclude that the DF-technology is mature with important benefits for the offshore production market in certain specific applications, most notably the FPSO's for fields in low gas to oil ratios, bringing important fuel cost savings and also for new-built F-LNG/FSO/FPSO's where the power plant can be accommodated below decks, freeing up valuable deck space for the process plant. (author)

Numerical study on aerodynamic damping of floating vertical axis wind turbines

Science.gov (United States)

Cheng, Zhengshun; Aagaard Madsen, Helge; Gao, Zhen; Moan, Torgeir

2016-09-01

Harvesting offshore wind energy resources using floating vertical axis wind turbines (VAWTs) has attracted an increasing interest in recent years. Due to its potential impact on fatigue damage, the aerodynamic damping should be considered in the preliminary design of a floating VAWT based on the frequency domain method. However, currently the study on aerodynamic damping of floating VAWTs is very limited. Due to the essential difference in aerodynamic load characteristics, the aerodynamic damping of a floating VAWT could be different from that of a floating horizontal axis wind turbine (HAWT). In this study, the aerodynamic damping of floating VAWTs was studied in a fully coupled manner, and its influential factors and its effects on the motions, especially the pitch motion, were demonstrated. Three straight-bladed floating VAWTs with identical solidity and with a blade number varying from two to four were considered. The aerodynamic damping under steady and turbulent wind conditions were estimated using fully coupled aero-hydro-servo-elastic time domain simulations. It is found that the aerodynamic damping ratio of the considered floating VAWTs ranges from 1.8% to 5.3%. Moreover, the aerodynamic damping is almost independent of the rotor azimuth angle, and is to some extent sensitive to the blade number.

Concept design and coupled dynamic response analysis on 6-MW spar-type floating offshore wind turbine

Science.gov (United States)

Meng, Long; Zhou, Tao; He, Yan-ping; Zhao, Yong-sheng; Liu, Ya-dong

2017-10-01

Tower, Spar platform and mooring system are designed in the project based on a given 6-MW wind turbine. Under wind-induced only, wave-induced only and combined wind and wave induced loads, dynamic response is analyzed for a 6-MW Spar-type floating offshore wind turbine (FOWT) under operating conditions and parked conditions respectively. Comparison with a platform-fixed system (land-based system) of a 6-MW wind turbine is carried out as well. Results demonstrate that the maximal out-of-plane deflection of the blade of a Spar-type system is 3.1% larger than that of a land-based system; the maximum response value of the nacelle acceleration is 215% larger for all the designed load cases being considered; the ultimate tower base fore-aft bending moment of the Spar-type system is 92% larger than that of the land-based system in all of the Design Load Cases (DLCs) being considered; the fluctuations of the mooring tension is mainly wave-induced, and the safety factor of the mooring tension is adequate for the 6-MW FOWT. The results can provide relevant modifications to the initial design for the Spar-type system, the detailed design and model basin test of the 6-MW Spar-type system.

Protective equipment against explosions for offshore oil and gas production; Explosionsgeschuetzte Ausruestung fuer den maritimen Oel- und Gassektor

Energy Technology Data Exchange (ETDEWEB)

Popp, Tobias [R. STAHL AG, Waldenburg (Germany)

2011-05-15

Offshore oil and gas production requires a multitude of explosion-proof components, systems and solutions both offshore and onshore. They serve different functions, from extraction and separation of fossil fuels to the production and storage of transportable products, sometimes on floating offshore platforms. There are also offshore cranes and pipelines to the onshore terminals. All this requires explostion-proof control cabinets, power distribution units and other equipment. The many different requirements are illustrated by the example of the world's biggest offshore production platform FPSO in the China Sea.

Application of partially diabatic divided wall column to floating liquefied natural gas plant

International Nuclear Information System (INIS)

Kim, Young Han

2014-01-01

The offshore operation of chemical plant requires the compactness of process equipments due to its harsh environment. A DWC (divided wall column), a compact ternary separator, is a good candidate for distillation process in the offshore operation. In this study the DWC is applied to the offshore FLNG (floating liquefied natural gas) plant, but high utility cost is required in the application because of the large difference of boiling points among feed components. A partially diabatic DWC is proposed for the reduction of the operating cost here, and its design procedure is presented along with performance and economic evaluations and the examination of thermodynamic efficiency as well. The heating duty of the proposed DWC including tray heat transfer is 35% less than that of the conventional system, and the cooling duty is 18% less. The evaluation indicates that some 16% less utility cost is used in the DWC compared with the conventional system, though 7% more investment is required. The exergy loss is reduced by 12%, and the thermodynamic efficiency is improved by 3.3 percentage point over the conventional system. - Highlights: • Diabatic divided wall column for FLNG (floating liquefied natural gas) plant. • Compact column for offshore operation. • 35% less heating duty required. • 16% lower utility necessary. • Exergy loss reduced by 12%

Response Analysis and Comparison of a Spar-Type Floating Offshore Wind Turbine and an Onshore Wind Turbine under Blade Pitch Controller Faults

DEFF Research Database (Denmark)

Etemaddar, M.; Blanke, Mogens; Gao, Z.

2016-01-01

in the controller dynamic link library and a short-term extreme response analysis is performed using the HAWC2 simulation tool.The main objectives of this paper are to investigate how different faults affect the performance of wind turbines for condition monitoring purposes and which differences exist...... in the structural responses between onshore and offshore floating wind turbines. Statistical analysis of the selected response parameters are conducted using the six1-hour stochastic samples for each load case.For condition monitoring purpose,the effects of faults on the responses at different wind speeds and fault...... amplitudes are investigated by comparing the same response under normal operation.The severities of the individual faults are categorized by the extreme values of structural loads and the structural components are sorted based on the magnitude of the fault effects on the extreme values.The pitch sensor fixed...

Hydrodynamic analysis of floating platform for special purposes under complex water environment

Science.gov (United States)

Ma, Guang-ying; Yao, Yun-long

2018-03-01

This article studied a new floating offshore platform for special purposes, which was assembled by standard floating modules. By using ANSYS AQWA software, the hydrodynamic model of the platform was established. The time history responses of the platform motions and the cable tension forces were calculate under complex water environments, such as wind, wave, current and mooring. The results showed that the tension of the four cables are far less than the breaking tension of the cable, so that the cable will not break. This study can be referenced by the relevant researchers and engineers.

Design and analysis of liquefaction process for offshore associated gas resources

International Nuclear Information System (INIS)

Li, Q.Y.; Ju, Y.L.

2010-01-01

Liquefaction is the key section on floating platform. Some experts and designers selected mixed refrigerant process for floating platform, while some recommended expander cycle. However, few of them compared the two types of processes systemically before making a choice. In this paper, the liquefaction processes of propane pre-cooled mixed refrigerant cycle (C 3 /MRC), mixed refrigerant cycle (MRC) and nitrogen expander cycle (N 2 expander) for the special offshore associated gases in South China Sea have been designed and studied. These processes have been analyzed and compared systematically considering the main factors including the performance parameters, economic performance, layout, sensitivity to motion, suitability to different gas resources, safety and operability, accounting for the features of the floating production, storage and offloading unit for liquefied natural gas (LNG-FPSO) in marine environment. The results indicated that N 2 expander has higher energy consumption and poorer economic performance, while it has much more advantages than C 3 /MRC and MRC for offshore application because it is simpler and more compact and thus requiring less deck area, less sensitive to LNG-FPSO motion, has better suitability for other gas resources, has higher safety and is easier to operate. Therefore, N 2 expander is the most suitable offshore liquefaction process. In addition, the exergy analysis is conducted for N 2 expander and the results indicate that the compression equipments and after coolers, expanders and LNG heat exchangers are the main contribution to the total exergy losses. The measures to decrease the losses for these equipments are then discussed.

Consequence assessment of floating and storage and off loading (FPSO) systems

International Nuclear Information System (INIS)

Smith, Duncan; Alderman, John A.

2000-01-01

Floating Production, Storage and Off loading (FPSO) systems are increasingly being used for deep water fields where use of traditional platforms and pipelines is not cost effective. The risks associated with FPSOs are inherently different from those for onshore facilities and conventional offshore platforms.This paper focuses on some of the key issues in the application of consequence assessment to FPSOs. A review and illustration of some of the techniques used for analysis of hydrocarbon hazards associated with FPSO operations will be included. Examples covered include evaluation of heat fluxes from a jet fire from an ignited riser leak and evaluation of explosion overpressure from a gas release on the main deck of the FPSO using ARAMAS. The assessment of the impact of smoke inhalation to personnel taking shelter in the accommodation block of the FPSO during a large fire event is also explained. Experiences gained from consequence assessments and quantitative risk analyses performed for offshore platforms, FPSOs, Floating Storage and Off loading (FSO) systems, as well as onshore refinery and petrochemical facilities will be detailed. (author)

Offshore Financial Centers in Global Capital Flow

Directory of Open Access Journals (Sweden)

Lutsyshyn Zoriana

2017-12-01

Full Text Available The article is dedicated to investigation of the place and role of offshore financial centers in financial globalization system, and of the reasons for using offshores in assets securitization mechanism. Numerous offshore and other preferential zones enabling to avoid the effective national and governmental tax regime are important attributes of global financial system and redistributive links of world financial flows. At present, around 70 countries and territories offer their offshore services for foreign capital, bank transactions, profitability from activities in financial markets proper. The global offshore business concentrates large amounts often having no relation to the country of origin, the so-called cosmopolitan capital (wandering. Although in the early 80's of the XXth century offshore companies were considered to control approximately 500 billion dollars, it was already in the early 90's that this amount doubled and was estimated as 1 trillion dollars. Today, from ⅓ to half of the world capital turnover goes through offshore business channels, and therefore, almost half of non-resident bank deposits are concentrated in world offshore centers. These are the world financial centers comprising international capital markets that provide for the accumulation and redistribution of world capital. From the process of reproduction (circulation of capital, the world financial centers plunge out the most homogeneous and mobile element — money, and freely manipulating with them, concentrate huge economic power in their hands. The role of world financial centers was also enhanced by the latest achievements in computer science, allowing execution of instant transactions and movement of huge amounts to any point of the world within the shortest possible time. The world financial centers consist not only of powerful banks and financial institutions operating on the international scene, but also have currency, stock and other exchanges as their

Experimental Study of an Offshore Wind Turbine TLP in ULS Conditions

DEFF Research Database (Denmark)

Wehmeyer, Christof; Ferri, Francesco; Skourup, Jesper

2013-01-01

An extensive model test program has been carried out in order to assess the behavior of a tension leg moored substructure as support of a floating offshore wind turbine (FOWT). The floater was inspired by an industrial design. The tests focused on the ultimate limit state (ULS) behavior, therefor...

Hywind floating wind turbine project

Energy Technology Data Exchange (ETDEWEB)

Crome, Tim

2010-07-01

The Hywind floating wind turbine concept was developed by StatoilHydro. Technip was awarded the contract for engineering, fabrication and installation of a demonstration unit in May 2008 and the completed wind turbine was installed mid June 2009 at the west coast of Norway on 220 m water depth. The demonstration unit will generate 2,3 MW and is equipped with instrumentation for monitoring mooring forces, strains and motions. The fabrication of the SPAR type steel substructure was performed at Technip Offshore Finland facilities in Pori and was towed horizontally from Finland to Norway, where it was upended to a vertical position by water filling. The completed floating wind turbine was towed vertically to the final location west of Karmoey and connected to the pre-installed three legged anchor system using an Anchor Handling Tug type vessel. The wind turbine test period is scheduled to start in September 2009. Statoil will monitor the performance of the system for two years before decision will be taken for further development. The paper will present the main challenges and lessons learned through design, fabrication and installation of this first of its kind structure. Main emphasis will be on the special challenges experienced for this floating, catenary moored, slender unit which is highly exposed for wind induced forces in addition to current and waves in hostile North Sea environments. (Author)

Turbomachinery systems for floating production applications

Energy Technology Data Exchange (ETDEWEB)

Windt, Jonathan P.; Kurz, Rainer [Solar Turbines Incorporated, San Diego, CA (United States)

2008-07-01

Since 1995 there has been a dramatic increase in oil and gas exploration and production using floating platforms in deeper waters located further offshore. This exploration started with tension leg platforms, progressed through SPARs and Semi-Submersibles, and later evolved into Floating Production Storage and Offloading (FPSO) vessels. Turbomachinery equipment installed on a floating platform or vessel will be expected to operate in the same manner as a land based machine, but in a variety of climate and environmental conditions that now includes motion. To operate successfully, specific design considerations for the turbo-machinery packages are required. It is critical to take into account the type of vessel, the expected list, trim and dynamic motion angles, the dynamic forces applied, the expected deck deflection as a result of those forces, understand the applicable class requirement, and where the equipment will be located on the vessel. This information is then translated into the design conditions to determine the type of mounting method to be used to attach the turbo-machinery package to the deck, the expected accelerations for structural analysis, and oil tank and system designs for fluid management. Furthermore, compressor designs need to allow utmost flexibility to adapt to changing operating conditions. (author)

Thermodynamic design of natural gas liquefaction cycles for offshore application

Science.gov (United States)

Chang, Ho-Myung; Lim, Hye Su; Choe, Kun Hyung

2014-09-01

A thermodynamic study is carried out for natural gas liquefaction cycles applicable to offshore floating plants, as partial efforts of an ongoing governmental project in Korea. For offshore liquefaction, the most suitable cycle may be different from the on-land LNG processes under operation, because compactness and simple operation are important as well as thermodynamic efficiency. As a turbine-based cycle, closed Claude cycle is proposed to use NG (natural gas) itself as refrigerant. The optimal condition for NG Claude cycle is determined with a process simulator (Aspen HYSYS), and the results are compared with fully-developed C3-MR (propane pre-cooled mixed refrigerant) JT cycles and various N2 (nitrogen) Brayton cycles in terms of efficiency and compactness. The newly proposed NG Claude cycle could be a good candidate for offshore LNG processes.

Design and Aero-elastic Simulation of a 5MW Floating Vertical Axis Wind Turbine

DEFF Research Database (Denmark)

Vita, Luca; Schmidt Paulsen, Uwe; Aagaard Madsen, Helge

2013-01-01

This paper deals with the design of a 5MW floating offshore Vertical Axis Wind Turbine (VAWT). The design is based on a new offshore wind turbine concept (DeepWind concept), consisting of a Darrieus rotor mounted on a spar buoy support structure, which is anchored to the sea bed with mooring lines......-DTU. The numerical simulations take into account the fully coupled aerodynamic and hydrodynamic loads on the structure, due to wind, waves and currents. The turbine is tested in operative conditions, at different sea states, selected according to the international offshore standards. The research is part...... of the European project DeepWind (2010-2014), which has been financed by the European Union (FP7-Future Emerging Technologies)....

Preliminary Design of a Multi-Column TLP Foundation for a 5-MW Offshore Wind Turbine

Directory of Open Access Journals (Sweden)

Yanping He

2012-10-01

Full Text Available Currently, floating wind turbines (FWTs may be the more economical and suitable systems with which to exploit offshore wind energy in deep waters. Among the various types of floating foundations for offshore wind farms, a tension leg platform (TLP foundation can provide a relatively stable platform for currently available offshore wind turbines without requiring major modifications. In this study, a new multi-column TLP foundation (WindStar TLP was developed for the NREL 5-MW offshore wind turbine according to site-specific environmental conditions, which are the same as the OC3-Hywind (NREL conditions. The general arrangement, main structure and mooring system were also designed and investigated through hydrodynamic and natural frequency analyses. The complete system avoids resonance through the rotor excitations. An aero-hydro-servo-elastic coupled analysis was carried out in the time domain with the numerical tool FAST. Statistics of the key parameters were obtained and analysed and comparisons to MIT/NREL TLP are made. As a result, the design requirements were shown to be satisfied, and the proposed WindStar TLP was shown to have favourable motion characteristics under extreme wind and wave conditions with a lighter and smaller structure. The new concept holds great potential for further development.

Design methods to assess the resistance of Offshore wind Turbine Structures impacted by a ship

OpenAIRE

Echeverry Jaramillo, Sara; Le Sourne, Hervé; Bela, Andreea; Pire, Timothée; Rigo, Philippe

2017-01-01

The dynamic modes of jacket, monopile and Floating offshore wind turbines (FOWT) after a collision event are presented. The authors have developed simplified analytical formulations based on plastic limit analysis to assess the resistance of an offshore wind turbine jacket impacted by a ship. For the case of collisions with monopile foundations and FOWT, the crushing behavior and structure dynamics are studied by means of finite element simulations. Numerical results for both monopile and flo...

Coastal effects of offshore energy systems. An assessment of oil and gas systems, deepwater ports, and nuclear power plants off the coast of New Jersey and Delaware. Volume II. Parts 1 and 2. Working papers 4 thru 10

International Nuclear Information System (INIS)

1976-11-01

This report consists of ten working papers prepared as background material for the assessment of the effects of three proposed offshore energy systems on the coastal areas of New Jersey and Delaware. The three proposed offshore energy systems are: exploration for and development of offshore oil and gas, deepwater ports for supertankers, and floating nuclear powerplants. The 10 working papers cover: federal and state regulation of the three systems, the biological impacts, the risk of oil spills in developing oil and gas resources and operating deepwater ports, the air and water quality impacts, regional energy supply and demand considerations, the fiscal effects of developing the three systems, environmental studies, a safety analysis of floating nuclear powerplants, an analysis of fuel and waste handling of floating nuclear powerplants, and an analysis of the economic considerations of floating nuclear powerplants

RAMSI management model and evaluation criteria for Nordic offshore wind asset

Energy Technology Data Exchange (ETDEWEB)

Tiusanen, R.; Jaennes, J. [VTT Technical Research Centre of Finland, Espoo (Finland); Liyanage, J. P. [Univ. of Stavanger, Center for Industrial Asset Management (Norway)

2012-07-01

The offshore wind energy sector is in the early stages of development, but it is growing fast. Due to the European Union's renewable-energy and climate goals along with national legislation, the offshore wind sector will develop strongly over the coming years in Europe. In the offshore wind energy sector, there are many different wind-turbine designs ranging from traditional mono pile structures to floating platforms, depending on the water depth. Today, most offshore turbines are based on onshore turbine designs, and turbine technology continues to develop incrementally. At the same time, there is strong demand in the market for new, innovative designs for offshore wind turbines whose main focus is reliability and cost efficiency. For floating offshore wind turbine designs, there may be new types of uncertainty and system risks compared with onshore wind turbines. Wind turbines in cold climates, such as those experienced in the Nordic countries, may be exposed to extreme conditions, such as formation of ice or very low temperatures that are outside the design limits of standard wind turbines. In the offshore wind energy sector, specification, implementation and verification of the so-called R&M's (Reliability, Availability, Maintainability, Safety and Inspect ability) requirements during development work are important for companies delivering wind turbines, from the perspective of system integrity. Decisions made before the formal design phase strongly determine the costs and benefits gained during the whole life cycle of a wind turbine. The benefits of implementing the R&M's program include support with investment decisions, cost management, improved management of resource requirements, systematic support with development and implementation of products, and integration of dependability and safety requirements. This publication outlines a model for managing R&M's factors during the conceptual design phase of an offshore wind turbine. The model

Loads for use in the design of ships and offshore structures

DEFF Research Database (Denmark)

Hirdaris, S.E.; Bai, W.; Dessi, Daniele

2014-01-01

The evaluation of structural responses is key element in the design of ships and offshore structures. Fundamental to this is the determination of the design loads to support the Rule requirements and for application in direct calculations. To date, the current design philosophy for the prediction...... of motions and wave-induced loads has been driven by empirical or first-principles calculation procedures based on well-proven applications such as ship motion prediction programs. In recent years, the software, engineering and computer technology available to predict the design loads imposed on ships...... and offshore structures has improved dramatically. Notwithstanding, with the stepwise increase in the size and structural complexity of ships and floating offshore installations and the advances in the framework of Rules and Standards it has become necessary to utilise the latest technologies to assess...

Innovative Offshore Wind Plant Design Study

Energy Technology Data Exchange (ETDEWEB)

Hurley, William L. [Glosten Associates, Inc., Seattle, WA (United States); Nordstrom, Charles J. [Glosten Associates, Inc., Seattle, WA (United States); Morrison, Brent J. [Glosten Associates, Inc., Seattle, WA (United States)

2013-12-18

Technological advancements in the Glosten PelaStar floating wind turbine system have led to projected cost of energy (COE) reductions from today’s best-in-class offshore wind systems. The PelaStar system is projected to deliver a COE that is 35% lower than that delivered by the current offshore wind plants. Several technology developments have been achieved that directly target significant cost of energy reductions. These include: Application of state-of-the-art steel construction materials and methods, including fatigue-resistant welding techniques and technologies, to reduce hull steel weight; Advancements in synthetic fiber tendon design for the mooring system, which are made possible by laboratory analysis of full-scale sub-rope specimens; Investigations into selected anchor technologies to improve anchor installation methods; Refinement of the installation method, specifically through development of the PelaStar Support Barge design. Together, these technology developments drive down the capital cost and operating cost of offshore wind plants and enable access to superb wind resources in deep water locations. These technology developments also reduce the uncertainty of the PelaStar system costs, which increases confidence in the projected COE reductions.

Stress analysis of partial sphere used for bottom shell of off-shore structure

International Nuclear Information System (INIS)

Nishimaki, Ko; Matsumoto, Kohei; Hori, Tohru; Takeshita, Haruyuki; Iwata, Setsuo

1976-01-01

In the near future, various huge off-shore structures will be constructed. Concrete shall become a leading material in the structures, owing to its versatile properties. One of the limitations of concrete is its low tensile strength. The problem of low tensile strength of concrete is dealt with in main by two different methods: by applying prestressing and by designing the structural configuration so that no tensile stresses appear. In the paper, the authors discuss the application of partially spherical shell to huge off-shore structures. Structural analysis by using the finite element method were done in order to investigate the feasibility of the structure. The results were arranged as to certain parameters to derive design charts by which the stresses of check points can be presumed. Optimum shape is also discussed. (auth.)

Offshore Wind Resource, Cost, and Economic Potential in the State of Maine

Energy Technology Data Exchange (ETDEWEB)

Musial, Walter D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2018-02-12

This report provides information for decision-makers about floating offshore wind technologies in the state of Maine. It summarizes research efforts performed at the National Renewable Energy Laboratory between 2015 and 2017 to analyze the resource potential, cost of offshore wind, and economic potential of offshore wind from four primary reports: Musial et al. (2016); Beiter et al. (2016, 2017); and Mone et al. (unpublished). From Musial et al. (2016), Maine's technical offshore wind resource potential ranked seventh in the nation overall with more than 411 terawatt-hours/year of offshore resource generating potential. Although 90% of this wind resource is greater than 9.0-meters-per-second average velocity, most of the resource is over deep water, where floating wind technology is needed. Levelized cost of energy and levelized avoided cost of energy were computed to estimate the unsubsidized 'economic potential' for Maine in the year 2027 (Beiter et al. 2016, 2017). The studies found that Maine may have 65 gigawatts of economic potential by 2027, the highest of any U.S. state. Bottom-line costs for the Aqua Ventus project, which is part of the U.S. Department of Energy's Advanced Technology Demonstration project, were released from a proprietary report written by NREL in 2016 for the University of Maine (Mone et al. unpublished). The report findings were that economies of scale and new technology advancements lowered the cost from $300/megawatt-hour (MWh) for the two-turbine 12-megawatt (MW) Aqua Ventus 1 project, to $126/MWh for the commercial-scale, 498-MW Aqua Ventus-2 project. Further cost reductions to $77/MWh were found when new technology advancements were applied for the 1,000-MW Aqua Ventus-3 project in 2030. No new analysis was conducted for this report.

Risks to offshore installations in Europe due to natural hazards

Science.gov (United States)

Necci, Amos; Krausmann, Elisabeth

2017-04-01

Natural hazards, such as storms, earthquakes, or lightning are a major threat to industry. In particular, chemical plants, storage facilities, pipelines, and offshore oil and gas facilities are vulnerable to natural events which can cause hazardous materials releases and thereby endanger workers, the population and the environment. These technological accidents are commonly referred to as Natech accidents. Recent events have increased concerns about safety in the offshore oil and gas sector, and the need for improving knowledge on the matter has become evident. With those premises, we analyzed accidents, near misses and accident precursors at offshore facilities in Europe caused by natural events using both a statistical and a qualitative approach. For this purpose, we screened the World Offshore Accident Database (WOAD) to identify all incidents that featured natural events as causes or aggravating factors. A dataset of 1,085 global Natech events was built for the statistical analysis. Among those, a subset composed of 303 European records was selected. The results of the analysis showed that offshore Natech events in Europe are frequent; they resulted, however, in low consequences. The main threat to offshore facilities resulted from bad weather, such as strong winds and heavy seas. Storms can put intense loads on the structural parts of offshore installations, eventually exceeding design resistance specifications. Several incidents triggered by lightning strikes and earthquakes were also recorded. Substantial differences in terms of vulnerability, damage modality and consequences emerged between fixed and floating offshore structures. The main damage mode for floating structures was the failure of station keeping systems due to the rupture of mooring or anchors, mainly caused by adverse meteorological conditions. Most of the incidents at fixed offshore structures in Europe involved falling loads for both metal jacket and concrete base platforms due to storms. In

Experimental Study on New Multi-Column Tension-Leg-Type Floating Wind Turbine

Science.gov (United States)

Zhao, Yong-sheng; She, Xiao-he; He, Yan-ping; Yang, Jian-min; Peng, Tao; Kou, Yu-feng

2018-04-01

Deep-water regions often have winds favorable for offshore wind turbines, and floating turbines currently show the greatest potential to exploit such winds. This work established proper scaling laws for model tests, which were then implemented in the construction of a model wind turbine with optimally designed blades. The aerodynamic, hydrodynamic, and elastic characteristics of the proposed new multi-column tension-leg-type floating wind turbine (WindStar TLP system) were explored in the wave tank testing of a 1:50 scale model at the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University. Tests were conducted under conditions of still water, white noise waves, irregular waves, and combined wind, wave, and current loads. The results established the natural periods of the motion, damping, motion response amplitude operators, and tendon tensions of the WindStar TLP system under different environmental conditions, and thus could serve as a reference for further research. Key words: floating wind turbine, model test, WindStar TLP, dynamic response

An Assessment of the Economic Potential of Offshore Wind in the United States from 2015 to 2030

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kilcher, Levi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maness, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-03-29

This study describes an assessment of the spatial variation of levelized cost of energy (LCOE) and levelized avoided cost of energy to understand the economic viability of fixed-bottom and floating offshore wind technologies across major U.S. coastal areas between 2015 and 2030. In particular, this study offers insights into the available offshore wind resource by region at different levels of LCOE and an assessment of the economically viable resource capacity in the United States.

Comparative evaluation of different offshore wind turbine installation vessels for Korean west–south wind farm

Directory of Open Access Journals (Sweden)

Dang Ahn

2017-01-01

Full Text Available The purpose of this study is to evaluate various means of wind power turbines installation in the Korean west–south wind farm (Test bed 100 MW, Demonstrate site 400 MW. We presented the marine environment of the southwest offshore wind farm in order to decide the appropriate installation vessel to be used in this site. The various vessels would be WTIV (Wind turbine installation vessel, jack-up barge, or floating crane … etc. We analyzed the installation cost of offshore wind turbine and the transportation duration for each vessel. The analysis results showed the most suitable installation means for offshore wind turbine in the Korean west–south wind farm.

The International Standards Organisation offshore structures standard

International Nuclear Information System (INIS)

Snell, R.O.

1994-01-01

The International Standards Organisation has initiated a program to develop a suite of ISO Codes and Standards for the Oil Industry. The Offshore Structures Standard is one of seven topics being addressed. The scope of the standard will encompass fixed steel and concrete structures, floating structures, Arctic structures and the site specific assessment of mobile drilling and accommodation units. The standard will use as base documents the existing recommended practices and standards most frequently used for each type of structure, and will develop them to incorporate best published and recognized practice and knowledge where it provides a significant improvement on the base document. Work on the Code has commenced under the direction of an internationally constituted sub-committee comprising representatives from most of the countries with a substantial offshore oil and gas industry. This paper outlines the background to the code and the format, content and work program

Recursive thoughts on the simulation of the flexible multibody dynamics of slender offshore structures

NARCIS (Netherlands)

Schilder, Jurnan Paul; Ellenbroek, Marcellinus Hermannus Maria; de Boer, A.

2017-01-01

In this work, the floating frame of reference formulation is used to create a flexible multibody model of slender offshore structures such as pipelines and risers. It is shown that due to the chain-like topology of the considered structures, the equation of motion can be expressed in terms of

Large Eddy Simulation of Flows Associated with Offshore Oil and Gas Pipeline

Directory of Open Access Journals (Sweden)

Nizamani Z.

2017-01-01

Full Text Available Fluid structure interaction (FSI applications are of wide range from offshore fixed and floating structures to offshore pipelines. Reynolds Averaged Navier Stoke (RANS solution has limitation for unsteady and turbulent flow modelling. A possible approach is Large Eddy Simulation (LES and it is applied to flows past a circular cylinder located far above, near and on a flat seabed. The Reynolds number considered is based on the real situation off Malaysia Coast and is sub-critical around 105. Hydrodynamic quantities in terms of mean pressure are predicted and vortex shedding mechanism is evaluated. The results are validated by comparing the simulation and experimental previous studies.

Effect of the number of blades on the dynamics of floating straight-bladed vertical axis wind turbines

DEFF Research Database (Denmark)

Cheng, Zhengshun; Aagaard Madsen, Helge; Gao, Zhen

2017-01-01

Floating vertical axis wind turbines (VAWTs) are promising solutions for exploiting the wind energy resource in deep waters due to their potential cost-of-energy reduction. The number of blades is one of the main concerns when designing a VAWT for offshore application. In this paper, the effect...

IEA Wind Task 23 Offshore Wind Technology and Deployment. Subtask 1 Experience with Critical Deployment Issues. Final Technical Report

DEFF Research Database (Denmark)

Lemming, Jørgen Kjærgaard

The final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports: Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). The Subtask 1 report included here provides background...... information and objectives of Task 23. It specifically discusses ecological issues and regulation, electrical system integration and offshore wind, external conditions, and key conclusions for Subtask 1. The Subtask 2 report covers OC3 background information and objectives of the task, OC3 benchmark exercises...... of aero-elastic offshore wind turbine codes, monopile foundation modeling, tripod support structure modeling, and Phase IV results regarding floating wind turbine modeling....

Experimental and Theoretical Analysis of a Combined Floating Wave and Wind Energy Conversion Platform

DEFF Research Database (Denmark)

Yde, Anders; Pedersen, Mads Mølgaard; Bellew, Sarah Bellew

This report presents results from the PSO project 2011-1-10668 entitled Poseidon 2. The project is a continuation of the previous PSO project entitled Aero-Hydro-Elastic Simulation Platform for Wave Energy Systems and floating Wind Turbines. Floating Power Plant has developed the technology...... for a novel, floating, wave- and wind-energy hybrid device. To test the technology they have scaled the design to P37, a 37 m wide test platform that has been undergoing offshore testing for four complete test phases (totaling more than 2 years). The test platform provides electricity to the grid from both...... wind and wave energy, however its purpose is purely for research and development. The PSO project has equipped the platform with comprehensive measurements equipment for measuring platform motion, wave and wind conditions and turbine loads. Data from the test periods has been used for evaluating...

Building and Calibration of a FAST Model of the SWAY Prototype Floating Wind Turbine: Preprint

Energy Technology Data Exchange (ETDEWEB)

Koh, J. H.; Robertson, A.; Jonkman, J.; Driscoll, F.; Ng, E. Y. K.

2013-09-01

Present efforts to verify and validate aero-hydro-servo-elastic numerical simulation tools that predict the dynamic response of a floating offshore wind turbine are primarily limited to code-to-code comparisons or code-to-data comparisons using data from wind-wave basin tests. In partnership with SWAY AS, the National Renewable Energy Laboratory (NREL) installed scientific wind, wave, and motion measurement equipment on the 1/6.5th-scale prototype SWAY floating wind system to collect data to validate a FAST model of the SWAY design in an open-water condition. Nanyang Technological University (NTU), through a collaboration with NREL, assisted in this validation.

A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015–2030

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kilcher, Levi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Damiani, Rick [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maness, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mooney, Meghan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

This report describes a comprehensive effort undertaken by the National Renewable Energy Laboratory (NREL) to understand the cost of offshore wind energy for markets in the United States. The study models the cost impacts of a range of offshore wind locational cost variables for more than 7,000 potential coastal sites in U.S. offshore wind resource areas. It also assesses the impact of more than 50 technology innovations on potential future costs for both fixed-bottom and floating wind systems. Comparing these costs to an initial site-specific assessment of local avoided generating costs, the analysis provides a framework for estimating the economic potential for offshore wind. The analysis is intended to inform a broad set of stakeholders and enable an assessment of offshore wind as part of energy development and energy portfolio planning. It provides information that federal and state agencies and planning commissions could use to inform initial strategic decisions about offshore wind developments in the United States.

Offshore wind; proposed study areas; Havvind; forslag til utredningsomraader

Energy Technology Data Exchange (ETDEWEB)

Drivenes, Arvid; Eirum, Tale; Johnson, Nils Henrik; Mindeberg, Sigrun Kavli; Lunde, Synnoeve; Undem, Linn Silje; Veggeland, Kirsti; Veie-Rosvoll, Brit; Voksoe, Astrid

2010-10-15

The report suggests areas that may be suitable for establishing of offshore wind power, and should be further evaluated in a strategic environmental impact assessment, as it is designed to through Proposition. No. 107 (2008-2009). The proposed areas is shown in Figure 1 Eleven of the areas suitable for fixed installations and four sites suitable for floating installations. The work of the report has been carried out by a Directorate group led by the Norwegian Water Resources and Energy Directorate. (AG)

Offshore Aquaculture Development in Ecuador

Directory of Open Access Journals (Sweden)

Julio López Alvarado

2016-03-01

Full Text Available Ecuador has a long tradition in aquaculture, mainly related to the cultivation of shrimp and tilapia in earthen ponds. Land-based production methods have a large environmental, economic and social impact due to the extensive use of land and its effects on the ecosystems. In order to increase the production of fish without further land use and with a lower environmental impact, a good alternative is the culture of fish in floating cages, adopting technologies used successfully in many other countries. This article analyses the current situation of offshore aquaculture (the production of fish and other aquatic organisms in the open sea in Ecuador, and the prospects for the future of this sector in the country.

Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint

Energy Technology Data Exchange (ETDEWEB)

Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.

2006-03-01

This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of

Damping Wind and Wave Loads on a Floating Wind Turbine

DEFF Research Database (Denmark)

Christiansen, Søren; Bak, Thomas; Knudsen, Torben

2013-01-01

Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due......, and we show the influence that both wind speed, wave frequencies and misalignment between wind and waves have on the system dynamics. A new control model is derived that extends standard turbine models to include the hydrodynamics, additional platform degrees of freedom, the platform mooring system...

A Floating Offshore Wind Turbine in Extreme Wave Conditions

DEFF Research Database (Denmark)

Wehmeyer, Christof

in order to include non-linear irregular incident waves as well as non-linear irregular incident waves with an embedded Stream-function wave. A linear background sea state into which a Stream-function wave was embedded was assumed no longer appropriate. Therefore a 2nd order sea state model was developed...... and served as well as the background sea state in which the Stream-function wave was embedded. The combined sea state was then applied in the numerical model in order to investigate the bow tendon responses of the FOWT TLP. A comparison of measured bow mooring responses and the numerically predicted bow......The PhD work evaluated the performance of engineering procedures, used in the design of bottom fixed offshore wind turbines, for the hydrodynamic ULS analysis of a FOWT tension leg platform (TLP). Dynamically sensitive topsides have been included and water depths were considered, where wave shapes...

Feasibility study on floating nuclear power station

International Nuclear Information System (INIS)

Kajima, Ryoichi

1987-01-01

It is stipulated that nuclear power plants are to be built on solid rock bases on land in Japan. However, there are a limited number of appropriate siting grounds. The Central Research Institute of Electric Power Industry has engaged since 1981 in the studies on the construction technology of power plants, aiming at establishing new siting technology to expand the possible siting areas for nuclear power plants. Underground siting is regarded as a proven technology due to the experience in underground hydroelectric power plants. The technology of siting on quaternary ground is now at the stage of verification. In this report, the outline of floating type offshore/inshore siting technology is introduced, which is considered to be feasible in view of the technical and economical aspects. Three fixed structure types were selected, of which the foundations are fixed to seabed, plant superstructures are above sea surface, and which are floating type. Aiming at ensuring the aseismatic stability of the plant foundations, the construction technology is studied, and the structural concept omitting buoyancy is possible. The most practical water depth is not more than 20 m. The overall plant design, earthquake isolation effect and breakwater are described. (Kako, I.)

A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015-2030

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp; Stehly, Tyler

2016-10-05

The potential for cost reduction and economic viability for offshore wind varies considerably within the United States. This analysis models the cost impact of a range of offshore wind locational cost variables across more than 7,000 potential coastal sites in the United States' offshore wind resource area. It also assesses the impact of over 50 technology innovations on potential future costs between 2015 and 2027 (Commercial Operation Date) for both fixed-bottom and floating wind systems. Comparing these costs to an initial assessment of local avoided generating costs, this analysis provides a framework for estimating the economic potential for offshore wind. Analyzing economic potential within this framework can help establish a refined understanding across industries of the technology and site-specific risks and opportunities associated with future offshore wind development. The findings from the original report indicate that under the modeled scenario, offshore wind can be expected to achieve significant cost reductions and may approach economic viability in some parts of the United States within the next 15 years.

Issues in offshore platform research - Part 1: Semi-submersibles

Science.gov (United States)

Sharma, R.; Kim, Tae-Wan; Sha, O. P.; Misra, S. C.

2010-09-01

Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

Faults in the Collection Grid of Offshore Wind Farms

DEFF Research Database (Denmark)

Lunow, Morten Erlandsson; Holbøll, Joachim; Henriksen, Mogens

2008-01-01

This paper deals with transient conditions in the collection grid of offshore wind farms under different faults. A model of a standard wind farm was established in two versions, with a floating and a grounded collection grid respectively. Line to ground faults and three-phase to ground faults were...... applied at critical points at worst-case phase angle and the results compared. The simulations show that it is better with a grounded collection grid, since lack of a ground reference will prevent the system from recovering after a line to ground fault....

Fighting Harmful Tax Competition Generated by Offshore Jurisdictions

Directory of Open Access Journals (Sweden)

Dan Drosu Saguna

2015-03-01

Full Text Available Harmful tax competition is not just tax system, but can also undermine the interests of local communities and the environment. Tax havens are a huge drain of resources from other countries (basic non tax haven to offshore areas. To operate, tax havens are supported economically, politically, and socially by high tax states. Also, by encouraging savings, it boosts investment and capital formation. Because they are low tax jurisdictions, they exert a higher tax on tax rates worldwide.

Floating substructure flexibility of large-volume 10MW offshore wind turbine platforms in dynamic calculations

International Nuclear Information System (INIS)

Borg, Michael; Hansen, Anders Melchior; Bredmose, Henrik

2016-01-01

Designing floating substructures for the next generation of 10MW and larger wind turbines has introduced new challenges in capturing relevant physical effects in dynamic simulation tools. In achieving technically and economically optimal floating substructures, structural flexibility may increase to the extent that it becomes relevant to include in addition to the standard rigid body substructure modes which are typically described through linear radiation-diffraction theory. This paper describes a method for the inclusion of substructural flexibility in aero-hydro-servo-elastic dynamic simulations for large-volume substructures, including wave-structure interactions, to form the basis of deriving sectional loads and stresses within the substructure. The method is applied to a case study to illustrate the implementation and relevance. It is found that the flexible mode is significantly excited in an extreme event, indicating an increase in predicted substructure internal loads. (paper)

Wave and offshore wind potential for the island of Tenerife

International Nuclear Information System (INIS)

Veigas, M.; Iglesias, G.

2013-01-01

Highlights: • The island aims to reduce its carbon footprint by developing renewable energy. • The substantial wave and offshore wind resources around the island are examined. • One area is appropriate for installing a hybrid wave–offshore wind farm. - Abstract: The island of Tenerife, a UNESCO Biosphere Reserve in the Atlantic Ocean, aims to be energy self-sufficient in order to reduce its carbon footprint. To accomplish this goal it should develop the renewable sources, in particular wave and offshore wind energy. The objectives of this work are twofold; (i) to characterize the wave and offshore wind power distribution around the island and (ii) to determine which offshore area is best suited for their exploitation, taking into account the resource and other conditioning factors such as the bathymetry, distance to the coastline and ports, and offshore zoning. To carry out this research, hindcast wave and wind data obtained with numerical models are used alongside observations from meteorological stations. One area, in the vicinity of Puerto de la Cruz, is identified as having great potential for installing a hybrid floating wave–wind farm. Both resources are characterized for the area selected: the wave resource in terms of wave directions, significant wave heights and energy periods; the offshore wind resource in terms of directions and speeds in addition to the seasonality for the both resources. It is found that most of the wave resource is provided by N and NNW waves with significant wave heights between 1.5 m and 3.0 m and energy periods between 10 s and 14 s. It follows that the Wave Energy Converters deployed in the area should have maximum efficiency in those ranges. As for the offshore wind resource, most of the energy corresponds to NNE and NE winds with speeds between 9 and 14 m s −1 , which should be taken into account when selecting the offshore wind turbines

A proposed national wind power R and D program. [offshore wind power system for electric energy supplies

Science.gov (United States)

Heronemus, W.

1973-01-01

An offshore wind power system is described that consists of wind driven electrical dc generators mounted on floating towers in offshore waters. The output from the generators supplies underwater electrolyzer stations in which water is converted into hydrogen and oxygen. The hydrogen is piped to shore for conversion to electricity in fuel cell stations. It is estimated that this system can produce 159 x 10 to the ninth power kilowatt-hours per year. It is concluded that solar energy - and that includes wind energy - is the only way out of the US energy dilemma in the not too distant future.

Gravitational and submersible offshore platform, and construction method. Nedsenkbar fralandsplattform av gravitasjonstypen og fremgangsmaate for fremstilling av samme

Energy Technology Data Exchange (ETDEWEB)

Berge, T.; Olsen, O.

1985-06-17

The invention concerns a submersible offshore platform of the gravitational type designed for great depths. The platform is made of concrete or the like comprising a sea-bed foundation, and a number of at least 3 cantilevered pillars connected to the prop section carrying the load-bearing structure and the platform deck. In addition, the platform consists of a cellular floating section, and the central part of it is lengthened upwards. The central column supports the prop section. There is a considerable space between the floating section and the bed foundation. The various steps of the construction methods are presented. 11 drawings.

Experimental study on the estimation method of hydrodynamic force acting on floating offshore structures; Futaishiki kaiyo kozobutsu ni kuwawaru ryutairyoku no suiteiho ni kansuru jikkenteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

Hoshino, K; Kato, S [Ship Research Inst., Tokyo (Japan); Koterayama, W [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

1996-04-10

In the design of various floating offshore structures (FOS), the functionality, safety and amenity of FOSs were examined by estimating responses of FOSs to environmental external forces such as wave, wind and flow. In this paper, the estimation method of drag acting on the whole FOS was established by combining previous study results on hydrodynamic force acting on various bodies such as Reynolds number effect (RNE), 3-D effect (TDE) and interference effect (IE). This hydrodynamic force was also compared with that obtained from the experiment result on a FOS model for TLP to confirm the applicability of this estimation method. The estimation result on the drag coefficient in steady flow by considering RNE, TDE and IE well agreed with experimental one. The drag coefficient acting on FOSs in heaving could be estimated in practically sufficient accuracy by considering drag acting on not columns but only square columns. The estimation result on the drag coefficient acting on FOSs in surging by considering RNE, TDE and IE well agreed with experimental one. 12 refs., 10 figs., 1 tab.

Issues in offshore platform research - Part 1: Semi-submersibles

Directory of Open Access Journals (Sweden)

R. Sharma

2010-09-01

Full Text Available Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

Model-based control of a ballast-stabilized floating wind turbine exposed to wind and waves

Energy Technology Data Exchange (ETDEWEB)

Christiansen, Soeren

2013-01-15

The wind turbine is a commercial product which is competing against other sources of energy, such as coal and gas. This competition drives a constant development to reduce costs and improve efficiency in order to reduce the total cost of the energy. The latest offshore development is the floating wind turbine, for water depths beyond 50 meters where winds are stronger and less turbulent. A floating wind turbine is subject to not only aerodynamics and wind induced loads, but also to hydrodynamics and wave induced loads. In contrast to a bottom fixed wind turbine, the floating structure, the hydrodynamics and the loads change the dynamic behavior of a floating wind turbine. Consequently, conventional wind turbine control cause instabilities on floating wind turbines. This work addresses the control of a floating spar buoy wind turbine, and focuses on the impact of the additional platform dynamics. A time varying control model is presented based on the wind speed and wave frequency. Estimates of the wind speed and wave frequency are used as scheduling variables in a gain scheduled linear quadratic controller to improve the electrical power production while reducing fatigue. To address the problem of negative damped fore-aft tower motion, additional control loops are suggested which stabilize the response of the onshore controller and reduce the impact of the wave induced loads. This research is then extended to model predictive control, to further address wave disturbances. In the context of control engineering, the dynamics and disturbances of a floating wind turbine have been identified and modeled. The objectives of maximizing the production of electrical power and minimizing fatigue have been reached by using advanced methods of estimation and control. (Author)

Adaptive Backstepping Control Based on Floating Offshore High Temperature Superconductor Generator for Wind Turbines

Directory of Open Access Journals (Sweden)

Feng Yang

2014-01-01

Full Text Available With the rapid development of offshore wind power, the doubly fed induction generator and permanent magnet synchronous generator cannot meet the increasing request of power capacity. Therefore, superconducting generator should be used instead of the traditional motor, which can improve generator efficiency, reduce the weight of wind turbines, and increase system reliability. This paper mainly focuses on nonlinear control in the offshore wind power system which is consisted of a wind turbine and a high temperature superconductor generator. The proposed control approach is based on the adaptive backstepping method. Its main purpose is to regulate the rotor speed and generator voltage, therefore, achieving the maximum power point tracking (MPPT, improving the efficiency of a wind turbine, and then enhancing the system’s stability and robustness under large disturbances. The control approach can ensure high precision of generator speed tracking, which is confirmed in both the theoretical analysis and numerical simulation.

The Effect of Additional Mooring Chains on the Motion Performance of a Floating Wind Turbine with a Tension Leg Platform

Directory of Open Access Journals (Sweden)

Jinping Ou

2012-04-01

Full Text Available In this study, two types of floating offshore wind turbine (FOWT systems were proposed: a traditional tension leg platform (TLP type and a new TLP type with additional mooring chains. They were both based on the National Renewable Energy Laboratory 5 MW offshore wind turbine model. Taking the coupled effect of dynamic response of the top wind turbine, tower support structure and lower mooring system into consideration, not only were the 1/60 scale model tests for the two floating wind turbine systems done in HIT’s wind-wave tunnel according to the typical design conditions in IEC61400-3 code, but also the numerical simulations corresponding to the scaled model tests were performed by advanced numerical tools. As a result, the numerical results displayed good agreement with the test data. Moreover, the additional mooring chains could play an active role in reducing the surge displacement, surge acceleration and typical tension leg force responses of the FOWT system, which is very beneficial for ensuring the good operational performance and the safety of the FOWT system.

Bilateral Floating Hip and Floating Knee: a Rare Complex Injury ...

African Journals Online (AJOL)

We report a rare complex injury of a 45-year-old man who sustained a bilateral floating hip and floating knee and hospitalised in our service six days after a traffic accident. The floating knees were open type III and II of Cauchoix score in phase of suppuration. He also presented with a floating ankle on the right side.

Feasibility study on floating nuclear power plant (1). Conceptual design study of FNPP. Contract research

International Nuclear Information System (INIS)

Yabuuchi, Noriaki; Shimazaki, Junya; Ochiai, Masaaki; Takahashi, Masao; Nakazawa, Toshio

2001-02-01

Offshore siting methods for a nuclear power plant are classified into three types as a floating type, a settled type and a land reclamation type. The floating nuclear power plant (FNPP) has a number of advantages, such as seismic isolation, standardization of design and manufacturing, and reduction of construction period. It is, however, required for FNPP to establish the safety standards, which are different from ones for land based nuclear power plant. Investigations for this subject have not been conducted sufficiently. In this report, design study on a concept for FNPP and a review on stability evaluation for the floating platform, which were performed in order to study the safety concept of the FNPP are described. The basic concept of the FNPP are described. The basic concept for FNPP is as follows: The FNPP is sited approximately 1 - 2km off the sea coast on the open sea with water depth of about 20m and it is moored of protected sea by the breakwater, it provide a floating platform for a 1,100MWe class PWR plant. The results of design study show that the floating platform for 1,100MWe class PWR plant of 300m (L) x 80m (W) x 35m (H), and displacement of approximately 300,000 ton can be constructed in a dockyard. This floating platform guarded by the breakwater is found to be stable enough to install the nuclear power plant from the analysis simulating the movement of the platform due to sea wave or wind. (author)

Feasibility study on floating nuclear power plant (1). Conceptual design study of FNPP. Construct research

Energy Technology Data Exchange (ETDEWEB)

Yabuuchi, Noriaki; Shimazaki, Junya; Ochiai, Masaaki [Department of Nuclear Energy System, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Takahashi, Masao [Niigata Engineering Co. Ltd., Tokyo (Japan); Nakazawa, Toshio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sato, Kazuo [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

2001-02-01

Offshore siting methods for a nuclear power plant are classified into three types as a floating type, a settled type and a land reclamation type. The floating nuclear power plant (FNPP) has a number of advantages, such as seismic isolation, standardization of design and manufacturing, and reduction of construction period. It is, however, required for FNPP to establish the safety standards, which are different from ones for land based nuclear power plant. Investigations for this subject have not been conducted sufficiently. In this report, design study on a concept for FNPP and a review on stability evaluation for the floating platform, which were performed in order to study the safety concept of the FNPP are described. The basic concept of the FNPP are described. The basic concept for FNPP is as follows: The FNPP is sited approximately 1 - 2km off the sea coast on the open sea with water depth of about 20m and it is moored of protected sea by the breakwater, it provide a floating platform for a 1,100MWe class PWR plant. The results of design study show that the floating platform for 1,100MWe class PWR plant of 300m (L) x 80m (W) x 35m (H), and displacement of approximately 300,000 ton can be constructed in a dockyard. This floating platform guarded by the breakwater is found to be stable enough to install the nuclear power plant from the analysis simulating the movement of the platform due to sea wave or wind. (author)

Ipsilateral Floating Hip and Floating Knee – A Rare Entity

Directory of Open Access Journals (Sweden)

Yashavantha Kumar

2013-04-01

Full Text Available Introduction: Ipsilateral floating hip and floating knee are very rare injuries. These injuries so uncommon that only three cases of similar kind have been reported. These injuries are due to high velocity injuries following motor vehicle accidents. Management of such complex injuries is a challenging task even in experienced hands as there are no standard treatment guidelines for such fractures. Case Report: We hereby report a 20 yr old male who sustained ipsilateral floating hip and ipsilateral floating knee injuries following motor vehicle accident. Patient was stabilized initially and later taken up for surgery. Patient was treated with interlocking nail for femur and tibia in the same sitting whereas acetabulam fracture was managed conservatively. At five months all the fractures united well with restoration of good range of motion in both hip and knee. Conclusion: Ipsilateral floating knee and floating hip are very rare injuries seen following high velocity motor vehicle accidents. There are no standard guidelines for treatment of those fractures as only a few cases of similar kind have been reported in literature. Early fixation and aggressive mobilization ensures fracture union and fewer complications. Keywords: Floating hip, Floating Knee, Ipsilateral.

Draft environmental statement related to the proposed manufacture of floating nuclear power plants (Docket No. STN 50-437)

International Nuclear Information System (INIS)

1976-10-01

The proposed action is the issuance of a manufacturing license to Offshore Power Systems for the startup and operation of a proposed manufacturing facility located at Blount Island, Jacksonville, Florida (Docket No. STN 50-436). No nuclear fuel will be handled or stored at the manufacturing site. The plants will be fueled after they have been towed to and moored within breadwaters at specific offshore locations designated by the purchaser and after an operating license has been issued by the Nuclear Regulatory Commision. Each nuclear generating plant, mounted on a floating platform, has a net capacity of 1150 MWe. This energy is provided by a pressurized water reactor steam supply system consisting of a Westinghouse four-loop 3425 MWt unit with an ice-condenser containment system. When one or more of these units is located within a single breakwater, the installation is designated an offshore power station. 3 figs., 1 tab

Artisanal fishing net float loss and a proposal for a float design solution

Directory of Open Access Journals (Sweden)

Paulo de Tarso Chaves

2016-03-01

Full Text Available Abstract Plastic floats from fishing nets are commonly found washed up on beaches in southern Brazil. They are usually broken and show signs of having been repaired. Characteristics of floats and interviews with fishermen suggest two main causes of float loss. First, collisions between active gear, bottom trawl nets for shrimp, and passive gear, drift nets for fish, destroy nets and release fragments of them, including floats. Second, the difficulty with which floats are inserted on the float rope of the nets when they are used near the surface. Floats are inserted to replace damaged or lost floats, or they may be removed if it is desired that the nets be used in deeper waters. Floats may thus be poorly fixed to the cables and lost. Here a new float design that offers greater safety in use and for the replacement of floats is described and tested.

Industrial waste - destination and valuation techniques of floating hoses: case study in Macaé, RJ

Directory of Open Access Journals (Sweden)

Marlon de Almeida Clemente Silva

2017-10-01

Full Text Available A large part of the oil extracted in Brazil today, is drained to the coast, or even transported to larger vessels through Floating Hoses. This oil unloading operation is called Offloading, it is of fundamental importance for the performance of offshore operations. These operating units use storage systems and oil relief, which can be FSO (Floating Storage Unit and Transfer or FPSO (Floating Production Unit, Stockpiling and Transfer. In this oil transshipment scenario, floating hoses have primary role therefore they are responsible for this operation. The Floating Hoses after useful life are discarded. How do the environmentally correct disposal of this waste? The destination most used for this waste are the landfills Class 2, for non-hazardous waste. In this study, we attempted to develop appropriate allocation techniques for Floating Hose, in order to obtain a greater appreciation potential of the materials that compose it, as well as presenting the risk of these being put up in a landfill, even if it is a controlled landfill. This technique is based on a so-called Reverse Manufacturing, all components are reused and recovered, with a more environmentally sound and economically viable destination. The research methodology was based on empirical studies of phenomenological framework, involving operational staff of a medium-sized company with a rising share of Treatment and Waste Disposal Market, in the city of Macaé. It was evidenced in the survey that there is a possibility of potential gains from the application of reverse manufacturing techniques of hoses, both in terms of environmental liability reductions and the financial return through the recovery of materials that compose them.

Active structural control of a floating wind turbine with a stroke-limited hybrid mass damper

Science.gov (United States)

Hu, Yaqi; He, Erming

2017-12-01

Floating wind turbines are subjected to more severe structural loads than fixed-bottom wind turbines due to additional degrees of freedom (DOFs) of their floating foundations. It's a promising way of using active structural control method to improve the structural responses of floating wind turbines. This paper investigates an active vibration control strategy for a barge-type floating wind turbine by setting a stroke-limited hybrid mass damper (HMD) in the turbine's nacelle. Firstly, a contact nonlinear modeling method for the floating wind turbine with clearance between the HMD and the stroke limiters is presented based on Euler-Lagrange's equations and an active control model of the whole system is established. The structural parameters are validated for the active control model and an equivalent load coefficient method is presented for identifying the wind and wave disturbances. Then, a state-feedback linear quadratic regulator (LQR) controller is designed to reduce vibration and loads of the wind turbine, and two optimization methods are combined to optimize the weighting coefficients when considering the stroke of the HMD and the active control power consumption as constraints. Finally, the designed controllers are implemented in high fidelity simulations under five typical wind and wave conditions. The results show that active HMD control strategy is shown to be achievable and the designed controllers could further reduce more vibration and loads of the wind turbine under the constraints of stroke limitation and power consumption. "V"-shaped distribution of the TMD suppression effect is inconsistent with the Weibull distribution in practical offshore floating wind farms, and the active HMD control could overcome this shortcoming of the passive TMD.

Industrial automation in floating production vessels for deep water oil and gas fields

International Nuclear Information System (INIS)

de Garcia, A.L.; Ferrante, A.J.

1990-01-01

The process supervision in offshore platforms was performed in the past through the use of local pneumatic instrumentation, based on relays, semi-graphic panels and button operated control panels. Considering the advanced technology used in the new floating production projects for deep water, it became mandatory to develop supervision systems capable of integrating different control panels, increasing the level of monitorization and reducing the number of operators and control rooms. From the point of view of field integration, a standardized architecture makes the communication between different production platforms and the regional headquarters, where all the equipment and support infrastructure for the computerized network is installed, possible. This test paper describes the characteristics of the initial systems, the main problems observed, the studies performed and the results obtained in relation to the design and implementation of computational systems with open architecture for automation of process control in floating production systems for deep water in Brazil

HAWCStab2 with super element foundations: A new tool for frequency analysis of offshore wind turbines

DEFF Research Database (Denmark)

Henriksen, Lars Christian; Hansen, Anders Melchior; Kragh, Knud Abildgaard

2013-01-01

HAWCStab2 is a linear frequency domain aero-elastic tool, developed by DTU Wind Energy, suitable for frequency and stability analysis of horizontal axis 3 bladed wind turbines [1]. This tool has now been extended to also handle complex offshore foundation types, such as jacket structures...... and floating structures with mooring lines, using super elements calculated by the nonlinear time domain aero-elastic code HAWC2 [2,3]....

Moored offshore structures - evaluation of forces in elastic mooring lines

Science.gov (United States)

Crudu, L.; Obreja, D. C.; Marcu, O.

2016-08-01

In most situations, the high frequency motions of the floating structure induce important effects in the mooring lines which affect also the motions of the structure. The experience accumulated during systematic experimental tests and calculations, carried out for different moored floating structures, showed a complex influence of various parameters on the dynamic effects. Therefore, it was considered that a systematic investigation is necessary. Due to the complexity of hydrodynamics aspects of offshore structures behaviour, experimental tests are practically compulsory in order to be able to properly evaluate and then to validate their behaviour in real sea. Moreover the necessity to carry out hydrodynamic tests is often required by customers, classification societies and other regulatory bodies. Consequently, the correct simulation of physical properties of the complex scaled models becomes a very important issue. The paper is investigating such kind of problems identifying the possible simplification, generating different approaches. One of the bases of the evaluation has been found consideringtheresults of systematic experimental tests on the dynamic behaviour of a mooring chain reproduced at five different scales. Dynamic effects as well as the influences of the elasticity simulation for 5 different scales are evaluated together. The paper presents systematic diagrams and practical results for a typical moored floating structure operating as pipe layer based on motion evaluations and accelerations in waves.

Numerical Prediction of Experimentally Observed Behavior of a Scale Model of an Offshore Wind Turbine Supported by a Tension-Leg Platform: Preprint

Energy Technology Data Exchange (ETDEWEB)

Prowell, I.; Robertson, A.; Jonkman, J.; Stewart, G. M.; Goupee, A. J.

2013-01-01

Realizing the critical importance the role physical experimental tests play in understanding the dynamics of floating offshore wind turbines, the DeepCwind consortium conducted a one-fiftieth-scale model test program where several floating wind platforms were subjected to a variety of wind and wave loading condition at the Maritime Research Institute Netherlands wave basin. This paper describes the observed behavior of a tension-leg platform, one of three platforms tested, and the systematic effort to predict the measured response with the FAST simulation tool using a model primarily based on consensus geometric and mass properties of the test specimen.

Stochastic dynamic response analysis of a floating vertical-axis wind turbine with a semi-submersible floater

DEFF Research Database (Denmark)

Wang, Kai; Moan, Torgeir; Hansen, Martin Otto Laver

2016-01-01

Floating vertical-axis wind turbines (FVAWTs) provide the potential for utilizing offshore wind resources in moderate and deep water because of their economical installation and maintenance. Therefore, it is important to assess the performance of the FVAWT concept. This paper presents a stochastic...... on the response is demonstrated by comparing the floating wind turbine with the equivalent land-based wind turbine. Additionally, by comparing the behaviour of FVAWTs with flexible and rigid rotors, the effect of rotor flexibility is evaluated. Furthermore, the FVAWT is also investigated in the parked condition...... dynamic response analysis of a 5MW FVAWT based on fully coupled nonlinear time domain simulations. The studied FVAWT, which is composed of a Darrieus rotor and a semi-submersible floater, is subjected to various wind and wave conditions. The global motion, structural response and mooring line tension...

Final environmental statement related to the proposed manufacture of floating nuclear power plants: (Docket No. STN 50-437): Part 2, A generic environmental statement considering the siting and operation of floating nuclear power plants

International Nuclear Information System (INIS)

1976-09-01

The proposed action is the issuance of a manufacturing license to Offshore Power Systems for the startup and operation of a proposed manufacturing facility located at Blount Island, Jacksonville, Florida (Docket No. STN 50-437). No nuclear fuel will be handled or stored at the manufacturing site. The plants will be fueled after they have been towed to and moored within protected basins at specific locations designated by the purchaser and after an operating license has been issued by the Nuclear Regulatory Commission. Each nuclear generating plant, mounted on a floating platform, has a net capacity of 1150 MWe. This energy is provided by a pressurized water reactor steam supply system consisting of a Westinghouse four-loop 3425-MWt unit with an ice-condenser containment system. When one or more of these units is located within a single breakwater, the installation is designated an offshore power station. 226 figs., 95 tabs

40 CFR 65.45 - External floating roof converted into an internal floating roof.

Science.gov (United States)

2010-07-01

... External floating roof converted into an internal floating roof. The owner or operator who elects to... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION...

Floating wind turbine system

Science.gov (United States)

Viterna, Larry A. (Inventor)

2009-01-01

A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

Validation of a vortex ring wake model suited for aeroelastic simulations of floating wind turbines

International Nuclear Information System (INIS)

Vaal, J B de; Moan, T; Hansen, M O L

2014-01-01

In order to evaluate aerodynamic loads on floating offshore wind turbines, advanced dynamic analysis tools are required. As a unified model that can represent both dynamic inflow and skewed inflow effects in it basic formulation, a wake model based on a vortex ring formulation is discussed. Such a model presents a good intermediate solution between computationally efficient but simple momentum balance methods and computationally expensive but complete computational fluid dynamics models. The model introduced is shown to be capable of modelling typical steady and unsteady test cases with reasonable accuracy

Concept Testing of a Simple Floating Offshore Vertical Axis Wind Turbine

DEFF Research Database (Denmark)

Friis Pedersen, Troels; Schmidt Paulsen, Uwe; Aagaard Madsen, Helge

2013-01-01

The wind energy community is researching new concepts for deeper sea offshore wind turbines. One such concept is the DeepWind concept. The concept is being assessed in a EU-FP7 project, called DeepWind. Objectives of this project are to assess large size wind turbines (5-20MW) based on the concept...... varying wind and wave conditions, and to compare such behaviour with computer code calculations. The concept turbine was designed and constructed by the project task partners, and all parts were assembled and installed at sea in the Roskilde fjord right next to DTU Risø campus. The turbine is under....... One task in the project is to test a 1kW concept rotor (not a scaled down MW size rotor) partly under field conditions in a fjord in Denmark, partly in a water tank under controlled conditions in Netherlands. The objective of testing the 1kW concept turbine is to verify the dynamical behaviour under...

Differences in plankton community structure and carbon cycling along a climate gradient from the Greenland Ice Sheet to offshore waters

DEFF Research Database (Denmark)

Arendt, K.E.; Nielsen, Torkel Gissel; Rysgaard, S.

Huge differences in plankton community structures and biomasses are observed along a climate gradient from the Greenland Ice Sheet to offshore waters at the West Greenland coast. The offshore region has a high biomass of copepods dominated by Calanus spp., which are capable of consuming 55....... Protozooplankton accounts for 20-38% of the carbon turnover in the offshore and inland areas. However, protozooplankton like copepods has low ability to turn over the primary production close to the Ice Sheet. Increased run of from the Greenland Ice Sheet due to global warming could displace the existing climate...... gradient. This would have a profound influence on the future plankton community structure as well as the energy transfer to higher trophic levels in Arctic coastal ecosystems....

Mooring Line Damping Estimation for a Floating Wind Turbine

Directory of Open Access Journals (Sweden)

Dongsheng Qiao

2014-01-01

Full Text Available The dynamic responses of mooring line serve important functions in the station keeping of a floating wind turbine (FWT. Mooring line damping significantly influences the global motions of a FWT. This study investigates the estimation of mooring line damping on the basis of the National Renewable Energy Laboratory 5 MW offshore wind turbine model that is mounted on the ITI Energy barge. A numerical estimation method is derived from the energy absorption of a mooring line resulting from FWT motion. The method is validated by performing a 1/80 scale model test. Different parameter changes are analyzed for mooring line damping induced by horizontal and vertical motions. These parameters include excitation amplitude, excitation period, and drag coefficient. Results suggest that mooring line damping must be carefully considered in the FWT design.

Mooring line damping estimation for a floating wind turbine.

Science.gov (United States)

Qiao, Dongsheng; Ou, Jinping

2014-01-01

The dynamic responses of mooring line serve important functions in the station keeping of a floating wind turbine (FWT). Mooring line damping significantly influences the global motions of a FWT. This study investigates the estimation of mooring line damping on the basis of the National Renewable Energy Laboratory 5 MW offshore wind turbine model that is mounted on the ITI Energy barge. A numerical estimation method is derived from the energy absorption of a mooring line resulting from FWT motion. The method is validated by performing a 1/80 scale model test. Different parameter changes are analyzed for mooring line damping induced by horizontal and vertical motions. These parameters include excitation amplitude, excitation period, and drag coefficient. Results suggest that mooring line damping must be carefully considered in the FWT design.

Challenges in Slug Modeling and Control for Offshore Oil and Gas Productions

DEFF Research Database (Denmark)

Pedersen, Simon; Løhndorf, Petar Durdevic; Yang, Zhenyu

2017-01-01

The upstream offshore multi-phase well-pipeline-riser installations are facing huge challenges related to slugging flow: An unstable flow regime where the flow rates, pressures and temperatures oscillate in the multi-phase pipelines. One typical severe slug is induced by vertical wells or risers...... most models require specific facility and operating data which, unfortunately, often is not available from most offshore installations. Anti-slug control have been investigated for several decades in oil & gas industry, but many of these existing methods suffer the consequent risk of simultaneously...... reducing the oil & gas production. This paper concludes that slug is a well defined phenomenon, but even though it has been investigated for several decades the current anti-slug control methods still have problems related to robustness. It is predicted that slug-induced challenges will be even more severe...

Comparative analysis of monetizing technologies for the use of offshore natural gas; Analise comparativa das tecnologias embarcadas de aproveitamento de gas natural

Energy Technology Data Exchange (ETDEWEB)

Biruel Junior, Jose

2008-09-15

The growing world need for natural gas, the issue of offshore oil and associated gas exploration in regions constantly farther from the consumer market, and the law restrictions due to greenhouses gases emissions have stimulated the development of technologies intended to monetizing stranded gas reserves. In order to compare these technologies, a Multi Criteria Decision Analysis Methodology, based on fuzzy parameters, has been developed. The Methodology enables specialists to define analysis dimensions and criteria as well as to assign weight and ratings by means of linguistic variables, resulting in a general performance index for each technology. The Methodology has been applied in a case study to compare the floating technologies FCNG (Floating Compressed Natural Gas), FLNG (Floating Liquefied Natural Gas), FGTL (Floating Gas-to-Liquid) and FGTW (Floating Gas-to- Wire). The efficacy of the Methodology depends on the comprehensiveness and quality of the information provided. Therefore, this dissertation presents a study of these technologies, placing strong emphasis on the Technological Dimension. The Methodology allows for the identification of the drawbacks of each technology so as to especially conduct R and D efforts to improve their competitiveness. (author)

FLOAT Project

DEFF Research Database (Denmark)

Sørensen, Eigil V.; Aarup, Bendt

The objective of the FLOAT project is to study the reliability of high-performance fibre-reinforced concrete, also known as Compact Reinforced Composite (CRC), for the floats of wave energy converters. In order to reach a commercial breakthrough, wave energy converters need to achieve a lower price...

Deformation Mechanisms of Offshore Monopile Foundations Accounting for Cyclic Mobility Effects

DEFF Research Database (Denmark)

Barari, Amin; Bagheri, Mohsen; Rouainia, Mohamed

2017-01-01

Highlights •There has been a huge surge in the construction of marine facilities (e.g., wind turbines) in Europe. •This paper presents some new frameworks for design strategy based on performance measures for cyclic horizontally loaded monopile foundations. •A three-dimensional finite element model...... was developed to investigate the behavior of large-diameter piles. •This model accounts for nonlinear dynamic interactions in offshore platforms under harsh combined moment and horizontal environmental loads. •Magnitude of cyclic loads was found to cause a linear increase in the accumulated rotation....

Safety of huge systems

International Nuclear Information System (INIS)

Kondo, Jiro.

1995-01-01

Recently accompanying the development of engineering technology, huge systems tend to be constructed. The disaster countermeasures of huge cities become large problems as the concentration of population into cities is conspicuous. To make the expected value of loss small, the knowledge of reliability engineering is applied. In reliability engineering, even if a part of structures fails, the safety as a whole system must be ensured, therefore, the design having margin is carried out. The degree of margin is called redundancy. However, such design concept makes the structure of a system complex, and as the structure is complex, the possibility of causing human errors becomes high. At the time of huge system design, the concept of fail-safe is effective, but simple design must be kept in mind. The accident in Mihama No. 2 plant of Kansai Electric Power Co. and the accident in Chernobyl nuclear power station, and the accident of Boeing B737 airliner and the fatigue breakdown are described. The importance of safety culture was emphasized as the method of preventing human errors. Man-system interface and management system are discussed. (K.I.)

Accessing offshoring advantages

DEFF Research Database (Denmark)

Mykhaylenko, Alona; Motika, Agnes; Wæhrens, Brian Vejrum

2015-01-01

. Assuming that different levels of synergy may exist between particular offshoring strategic decisions (choosing offshore outsourcing or captive offshoring and the type of function) and different offshoring advantages, this work advocates that the actual fact of realization of certain offshoring advantages...

Reconstruction of juxta-articular huge defects of distal femur with vascularized fibular bone graft and Ilizarov's distraction osteogenesis.

Science.gov (United States)

Lai, Davy; Chen, Chuan-Mu; Chiu, Fang-Yao; Chang, Ming-Chau; Chen, Tain-Hsiung

2007-01-01

We evaluate the effect of reconstructing huge defects (mean, 15.8 cm) of the distal femur with Ilizarov's distraction osteogenesis and free twin-barreled vascularized fibular bone graft (TVFG). We retrospectively reviewed a consecutive series of five patients who had cases of distal femoral fractures with huge defects and infection that were treated by the Ilizarov's distraction osteogenesis. After radical debridement, two of the five cases had free TVFG and monolocal distraction osteogenesis, and another two cases had multilocal distraction osteogenesis with knee fusion because of loss of the joint congruity. The other case with floating knee injury had bilocal distraction osteogenesis and a preserved knee joint. The mean defect of distal femur was 15.8 cm (range, 14-18 cm) in length. The mean length of distraction osteogenesis by Ilizarov's apparatus was 8.2 cm. The mean length of TVFG was 8 cm. The average duration from application of Ilizarov's apparatus to achievement of bony union was 10.2 months (range, 8-13 months). At the end of the follow-up, ranges of motion of three knees were 0 to 45 degrees, 0 to 60 degrees, and 0 to 90 degrees. Two cases had knee arthrodesis with bony fusion because of loss of the joint congruity. There were no leg length discrepancies in all five patients. In addition, three patients had pin tract infections and one case had a 10 degree varus deformity of the femur. Juxta-articular huge defect (>10 cm) of distal femur remains a challenge to orthopedic surgeons. Ilizarov's technique provides the capability to maintain stability, eradicate infection, restore leg length, and to perform adjuvant reconstructive procedure easily. In this study, we found that combining Ilizarov's distraction osteogenesis with TVFG results in improved patient outcome for patients with injuries such as supracondylar or intercondylar infected fractures or nonunion of distal femur with huge bone defect.

Impact of offshore nuclear generating stations on recreational behavior at adjacent coastal sites

International Nuclear Information System (INIS)

Baker, E.J.; West, S.G.; Moss, D.J.; Weyant, J.K.

1977-10-01

A multi-faceted investigation was undertaken to project the impact of offshore nuclear power plants on beach visitation at adjacent beaches. Related literature was reviewed concerning human adjustment to natural hazards, risk-taking behavior, and public attitudes toward nuclear power. Approximately 2400 people were interviewed at beaches in three states with respect to: intended avoidance of beaches near a hypothetical floating nuclear plant (FNP), relative importance of proximity to a FNP, when compared to other beach attributes, onshore-offshore preference for coastal nuclear plant location, behavioral impact of NRC licensing of FNPs, relative tourism impact of coastal nuclear plant compared to coastal coal-fired plant, public concerns about nuclear safety, public attitudes toward alternative energy sources, public confidence in sources of information about nuclear power, visual impact of a FNP, and knowledge about nuclear power. Four beach areas near currently operating coastal nuclear power plants were studied to assess impacts on tourism resulting from plant construction. Data suggest that proximity of a FNP is less important than other beach attributes in determining beach attractiveness, probably no more than (and perhaps less than) 5% to 10% of current beach patrons would avoid a beach after FNP siting three miles directly offshore, and impact of a FNP would decrease exponentially as distance away increased

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

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

Handbook of floating-point arithmetic

CERN Document Server

Muller, Jean-Michel; de Dinechin, Florent; Jeannerod, Claude-Pierre; Joldes, Mioara; Lefèvre, Vincent; Melquiond, Guillaume; Revol, Nathalie; Torres, Serge

2018-01-01

This handbook is a definitive guide to the effective use of modern floating-point arithmetic, which has considerably evolved, from the frequently inconsistent floating-point number systems of early computing to the recent IEEE 754-2008 standard. Most of computational mathematics depends on floating-point numbers, and understanding their various implementations will allow readers to develop programs specifically tailored for the standard’s technical features. Algorithms for floating-point arithmetic are presented throughout the book and illustrated where possible by example programs which show how these techniques appear in actual coding and design. The volume itself breaks its core topic into four parts: the basic concepts and history of floating-point arithmetic; methods of analyzing floating-point algorithms and optimizing them; implementations of IEEE 754-2008 in hardware and software; and useful extensions to the standard floating-point system, such as interval arithmetic, double- and triple-word arithm...

Numerical hydrodynamic analysis of an offshore stationary–floating oscillating water column–wave energy converter using CFD

Directory of Open Access Journals (Sweden)

Ahmed Elhanafi

2017-01-01

Full Text Available Offshore oscillating water columns (OWC represent one of the most promising forms of wave energy converters. The hydrodynamic performance of such converters heavily depends on their interactions with ocean waves; therefore, understanding these interactions is essential. In this paper, a fully nonlinear 2D computational fluid dynamics (CFD model based on RANS equations and VOF surface capturing scheme is implemented to carry out wave energy balance analyses for an offshore OWC. The numerical model is well validated against published physical measurements including; chamber differential air pressure, chamber water level oscillation and vertical velocity, overall wave energy extraction efficiency, reflected and transmitted waves, velocity and vorticity fields (PIV measurements. Following the successful validation work, an extensive campaign of numerical tests is performed to quantify the relevance of three design parameters, namely incoming wavelength, wave height and turbine damping to the device hydrodynamic performance and wave energy conversion process. All of the three investigated parameters show important effects on the wave–pneumatic energy conversion chain. In addition, the flow field around the chamber's front wall indicates areas of energy losses by stronger vortices generation than the rear wall.

Seabird data collected by the Grand Banks offshore hydrocarbon industry 1999-2002 : results, limitations and suggestions for improvement

International Nuclear Information System (INIS)

Baillie, S.M.; Robertson, G.J.; Wiese, F.K.

2005-01-01

Offshore oil operations attract and concentrate migratory seabirds through an artificially enhanced food supply and lights. In order to understand the vulnerability of seabirds near offshore oil facilities, the degree of association of seabirds with these sites must be determined. Offshore oil and gas exploration on Newfoundland's Grand Banks began in the early 1980s, with first oil produced in 1997 at the Hibernia fixed platform. Additional production followed in 2002 from the Terra Nova Floating Production Storage and Offloading Vessel. As the Grand Banks oil industry grows, seismic surveys continue to be conducted and an estimated 30,000 litres of crude oil and synthetic based drilling fluids have been spilled from exploration drilling, development drilling and production oil operations between 1997 and 2002. Most of the spills occurred in winter when the number of seabirds on the Grand Banks are highest and most vulnerable to oil pollution. This report presents an evaluation of the current Grand Banks offshore oil and gas development seabird monitoring programs. It focuses mostly on seabird monitoring on fixed platforms. The objective was to assess the scientific quality of seabird-related industry programs by compiling and summarizing all available spatial and temporal seabird abundance data and deck stranded birds associated with Grand Banks offshore oil platforms from 1997 to 2002. Data on seabird distributions at sea and stranded bird encounters was collected from 8 offshore hydrocarbon sites on the northeastern Grand Banks. It was recommended that a standardized seabird monitoring and observer training program for the offshore operations in the Grand Banks region be implemented. 43 refs., 5 tabs., 16 figs., 3 appendices

Alternative ways to transport natural gas; Transporte alternativo de gas natural

Energy Technology Data Exchange (ETDEWEB)

Moura, N.R.; Campos, F.B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

The Brazilian energy matrix has been showing a huge increase in the demand of natural gas due mainly to industries and power plants. Today the Brazilian gas market is supplied with gas produced by PETROBRAS and imported from Bolivia. To increase the Brazilian gas supply, on the short and middle term, PETROBRAS will import LNG (liquefied natural gas) and exploit the new offshore fields discovered on the pre-salt area. The only proven technology available today to bring this offshore gas to the market is the pipeline, but its costs for the pre-salt area are high enough to keep the solution economically attractive. So, PETROBRAS are evaluating and developing alternative ways to transport offshore gas, such as LNG, CNG (Compressed Natural Gas), GTS (Gas-to-Solids or Natural Gas Hydrates) and ANG (Adsorbed Natural Gas). Using information available in the literature, this paper analyses the main concepts of CNG and LNG floating unities. This paper also presents the PETROBRAS R and D results on ANG and GTS aiming at offshore application. (author)

Integration of Wave and Offshore Wind Energy in a European Offshore Grid

DEFF Research Database (Denmark)

Chozas, Julia Fernandez; Sørensen, H. C.; Korpås, M.

2010-01-01

of offshore renewable energy sources. According to this, the paper covers i) public and private initiatives for offshore transmission networks, ii) the synergies between the wave and the offshore wind energy sector within an offshore grid, iii) power transmission options for offshore generation and iv...

Connecting slow earthquakes to huge earthquakes.

Science.gov (United States)

Obara, Kazushige; Kato, Aitaro

2016-07-15

Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

Present situation of floating nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Sakurai, A [Central Research Inst. of Electric Power industry, Tokyo (Japan)

1975-08-01

The present situation of investigation and the future problems of floating nuclear power plants in Japan are examined, referring to those in USA. The committee report on a new power generation system in 1970 is quoted. In this report, the site conditions are supposed to be 5 km offshore, 100m water depth, 60 m/sec wind velocity, 10 m wave height, 200 m wave length, 12 seconds wave period 0.2 g earthquake acceleration, and 2.5 knots tide current. The semisubmersible hull of double construction 15 m under water is employed. A pair of 1,000,000 kW BWR reactors are utilized. A sea water desalting unit using bleed steam from turbines is installed. The solid radioactive wastes packed in drums are disposed in the sea. The design and cost estimation were made. The names of the organizations who have made investigation in this field, namely the Civil Engineering Society, the Sience and Technology Agency and other several centers, are reported. The Chubu Electric Power Company is forwarding its project. Referring to the investigations in USA, the project of Atlantic nuclear power station unit is described. A report of plant design has been submitted by O.P.S. to United States Atomic Energy Commission in 1973. The Coastal Area Facilities Act was instituted in New Jersey in 1973. Although the Atlantic nuclear power station has been postponed, it is the most feasible project. For the realization of a floating nuclear power plant in Japan, investigation must be started on the ground construction that can endure the construction of breakwater in water depth of 14 to 30 meter.

Strength Analysis of a Large-Size Supporting Structure for an Offshore Wind Turbine

Directory of Open Access Journals (Sweden)

Niklas Karol

2017-04-01

Full Text Available The offshore wind power industry is the branch of electric energy production from renewable sources which is most intensively developed in EU countries. At present, there is a tendency to install larger-power wind turbines at larger distances from the seashore, on relatively deep waters. Consequently, technological solutions for new supporting structures intended for deeper water regions are undergoing rapid development now. Various design types are proposed and analysed, starting from gravitational supports (GBS, through monopiles and 3D frame structures (jackets, tripods, and ending with floating and submerged supports anchored to the seabed by flexible connectors, including TLP type solutions.

14 CFR 27.753 - Main float design.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential...

14 CFR 29.753 - Main float design.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 29.753 Section 29.753... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential...

Occupational health offshore

Energy Technology Data Exchange (ETDEWEB)

Crosbie, A.; Davies, F.

2002-07-01

The proceedings contain the 29 papers presented at the conference plus the opening address from the chair of the Health and Safety Commission. The papers in the first session were concerned with policy, strategy and leadership and included a perspective from the offshore industry advisory committee, details of a health planning tool for occupational health assurance and lessons from occupational health management in the offshore sector. The two sessions on the second day dealt with occupational health in the offshore design process and case studies involving physical, chemical and biological agents. Topics included the need to consider occupational health when designing offshore installations, the development of a human factors engineering strategy in petrochemical engineering projects, measuring occupational exposure to hazardous chemicals, implementation of the noise at work regulations, hand arm vibration syndrome and issues with potable water maintenance. The two sessions on the third day were concerned with human factors and psychological health, and well-being and fitness for duty. Topics covered included circadian adaption to shift change in offshore shift workers, managing stress in the offshore environment, the role of employee assistance programmes in organisational stress management, health care and first aid (the revised ACOP), well-being at work, the medical and physical fitness of offshore emergency response rescue team members, the impact of health surveillance and promotion of offshore accident rates, and the implication of safety and heath of the aging of the workforce ion the Norwegian offshore industry.

Offshoring Process

DEFF Research Database (Denmark)

Slepniov, Dmitrij; Sørensen, Brian Vejrum; Katayama, Hiroshi

2011-01-01

The purpose of this chapter is to contribute to the knowledge on how production offshoring and international operations management vary across cultural contexts. The chapter attempts to shed light on how companies approach the process of offshoring in different cultural contexts. In order...... of globalisation. Yet there are clear differences in how offshoring is conducted in Denmark and Japan. The main differences are outlined in a framework and explained employing cultural variables. The findings lead to a number of propositions suggesting that the process of offshoring is not simply a uniform...... technical-rational calculation of the most efficient organisation of activities across national borders, but it is rather specific to the parent companies’ national contexts....

Wave attenuation charcteristics of tethered float system

Digital Repository Service at National Institute of Oceanography (India)

Vethamony, P.

incident wave height transmitted wave height G wave number float mass number of rows of floats drag power transmitted wave power incident wave power 111 112 P. Vethamony float radius wave period time velocity and acceleration of fluid... particles, respectively wave attenuation in percentage displacement, velocity and acceleration of float, respectively amplitude of float displacement added mass damping coefficient fluid particle displacement amplitude of fluid particle displacement...

FLOAT Project - Task 1

DEFF Research Database (Denmark)

Marchalot, Tanguy; Kofoed, Jens Peter; Sørensen, Eigil V.

.com, 2011). CRC floats could be a very cost-effective technology with enhanced loading capacity and environmental resistance, and very low maintenance requirements, affecting directly the final energy price. The project involves DEXA Wave Energy Ltd, Wave Star A/S, Aalborg University and Hi-Con A......The objective of the FLOAT project is to study the reliability of high-performance fibre-reinforced concrete, also known as Compact Reinforced Composite (CRC), for the floats of wave energy converters. In order to reach commercial breakthrough, wave energy converters need to achieve a lower price...

Petrological and geochemical Highlights in the floating fragments of the October 2011 submarine eruption offshore El Hierro (Canary Islands): Relevance of submarine hydrothermal processes

Science.gov (United States)

Rodriguez-Losada, Jose A.; Eff-Darwich, Antonio; Hernandez, Luis E.; Viñas, Ronaldo; Pérez, Nemesio; Hernandez, Pedro; Melián, Gladys; Martinez-Frías, Jesús; Romero-Ruiz, M. Carmen; Coello-Bravo, Juan Jesús

2015-02-01

This paper describes the main physical, petrological and geochemical features of the floating fragments that were emitted in the initial stages of the 2011-2012 submarine eruption off the coast of the Canarian island of El Hierro, located 380 km from the Northwest African Coast. It attempts to assess the potential of radiometric analyses to discern the intriguing origin of the floating fragments and the differences between their constituent parts. In this regard, the material that conforms the core of the fragments contains the largest concentration of uranium (U) ever found in volcanic rocks of the Canary Islands. This enrichment in U is not found in the content of thorium (Th), hence the floating fragments have an unusual U/Th ratio, namely equal to or larger than 3. Although the origin of this material is under discussion, it is proposed that the enrichment in U is the result of hydrothermal processes.

Device for retaining oil gushing out in an uncontrolled fashion from offshore platforms. [German patent

Energy Technology Data Exchange (ETDEWEB)

Hambrock, H J

1978-11-23

The spread of oil which emerges on a water surface in case of a fault is to be prevented and its removal is to be made possible by a sort of floating fence. This type of oil barrier is formed by a blown up, floating hose on the water surface which may be filled with plastic foam. It surrounds the centrally placed possible place of emergence of the oil in a circle, this may be an offshore platform or a stationary tanker. The concentric position is ensured by radially tensioned ropes. The protective ring can normally be pulled in (above all during bad weather) and need only be expanded for a short time in case of a fault. In order to prevent oil collected inside the protective ring being washed under or over it by the wind or waves, a circular attachment in the form of a collar can be blown up in the upward direction, and a similar apron hanging downwards loaded with weights may be provided.

Offshore Investment Funds

Directory of Open Access Journals (Sweden)

Shang-Jin Wei

1999-12-01

Full Text Available Offshore investment funds are alleged to have engaged in trading behavior that is different from their onshore counterparts because they may be subject to less supervision and regulation. In particular, they may trade more intensely. They could also pursue more aggressively certain trading strategies such as positive feedback trading or herding that could contribute to a greater volatility in the market. Using a unique data set, this chapter compares the trading behavior in the Korean stock market between offshore investment funds with their onshore counterparts registered in the US and UK. There are a number of interesting findings. First, there is indeed evidence suggesting that the offshore funds trade more intensely than their onshore counterparts. Second, however, there is no evidence that the offshore funds engage in positive feedback trading. In contrast, there is strong evidence that the funds from the U.S. and U.K. do. Third, while offshore funds do herd, they do so far less than onshore funds in the U.S. or UK. Fourth, offshore funds hold less glamour stocks (e.g. stocks with high P/E in their portfolio than funds in the U.S. or U.K. do. Moreover, flight to glamour stocks during the in-crisis period is less evident in the case of offshore funds. In sum, offshore funds are no especially worrisome monsters.

Floating Microparticulate Oral Diltiazem Hydrochloride Delivery ...

African Journals Online (AJOL)

Purpose: To formulate and evaluate floating microparticulate oral diltiazem delivery system for possible delivery to the heart. Method: Floating microspheres were prepared using cellulose acetate and Eudragit RS100 polymers by emulsion solvent evaporation technique. The dried floating microspheres were evaluated for ...

A huge cystic craniopharyngioma

International Nuclear Information System (INIS)

Takamura, Seishi; Fukumura, Akinobu; Ito, Yoshihiro; Itoyama, Yoichi; Matsukado, Yasuhiko.

1986-01-01

The findings of computed tomography (CT) of a huge cystic craniopharyngioma in a 57-year-old woman are described. Cyst density varied from low to high levels in a short duration. Follow-up CT scans were regarded as important to diagnose craniopharyngioma. The mechanism of increment of cyst density was discussed. (author)

Electrically floating, near vertical incidence, skywave antenna

Science.gov (United States)

Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

2014-07-08

An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

Whether and What to Offshore?

DEFF Research Database (Denmark)

Jensen, Peter Ørberg; Pedersen, Torben

In this article, we explore the idea that offshoring of services and technical work should be regarded as a dynamic process that evolves over time. Firms gradually move from offshoring of simple, standardized activities towards offshoring of advanced activities when they accumulate experience...... with offshoring, and this type of offshoring comes with an entirely different set of characteristics compared to traditional, cost-seeking offshoring. Based on a unique survey among the total population of firms in the eastern region of Denmark, we analyze some of the dynamics of this process through a model...... that incorporates two different aspects of the process of offshoring. First, we approach the question of whether to offshore and establish a baseline that investigates the determinants of firms’ participation—or lack thereof—in offshoring. Secondly, we approach the question of what to offshore and the subsequent...

14 CFR 23.753 - Main float design.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521. [Doc...

Impact of offshore nuclear generating stations on recreational behavior at adjacent coastal sites. Technical report

International Nuclear Information System (INIS)

Baker, E.J.; Moss, D.J.; West, S.G.; Weyant, J.K.

1977-12-01

A multi-faceted investigation was undertaken to project the impact of offshore nuclear power plants on beach visitation at adjacent beaches. 1. Related literature was reviewed concerning human adjustment to natural hazards, risk-taking behavior, and public attitudes toward nuclear power. 2. Approximately 2400 people were interviewed at beaches in three states with respect to: (a) intended avoidance of beaches near a hypothetical floating nuclear plant (FNP), (b) relative importance of proximity to a FNP, when compared to other beach attributes, (c) onshore-offshore preference for coastal nuclear plant location, (d) behavioral impact of NRC licensing of FNP's, (e) relative tourism impact of coastal nuclear plant compared to coastal coal-fired plant, (f) public concerns about nuclear safety, (g) public attitudes toward alternative energy sources, (h) public confidence in sources of information about nuclear power, (i) visual impact of a FNP, and (j) knowledge about nuclear power. 3. Four beach areas near currently operating coastal nuclear power plants were studied to assess impacts on tourism resulting from plant construction. Data suggest that proximity of a FNP is less important than other beach attributes in determining beach attractiveness, probably no more than (and perhaps less than) 5% to 10% of current beach patrons would avoid a beach after FNP siting three miles directly offshore, and impact of a FNP would decrease exponentially as distance away increased

Stochastic study on entrainment of floating particles with intake of cooling water of a power plant

International Nuclear Information System (INIS)

Kadoyu, Masatake; Wada, Akira

1979-01-01

The mortality of ichthyoplanktons, contained in the sea water passing through the cooling water systems of a power plant, may be associated with rising temperature and mechanical effect. In this study, the range and the rate of entrainment of the organisms like ichthyoplanktons floating in the sea caused by the intake of cooling water were stochastically investigated by simulating the average current as well as the flow caused by the intake of water and by taking into consideration random velocity fluctuation without these flows, using a mathematical model. An intake was set along the straight coastline in semi-infinite sea, and the rate of inflow of particles into the intake was simulated by a mathematical model. In the numerical simulation, the average flow as coastal current component and the flow caused by the intake of water were obtained with the hydrodynamic equations of motion and continuity, and the rate of entrainment of floating particles was examined by giving turbulence to the particles in the sea and by calculating the position of each particle every moment. The results are as follows; 1) The range of entrainment of floating particles by the intake of cooling water and its probability were obtained in consideration of the flow rate of cooling water, coast current velocity and diffusion coefficient as parameters. 2) The extent of inflow of floating particles considerably varied with tidal amplitude, diffusion coefficient and the flow rate of cooling water in the sea where the coastal flow has clear periodicity. 3) The extent of entrainment was considerably influenced by the steady current velocity, the velocity distribution in offshore direction and the intake volume in the sea where periodicity is not observed. (Nakai, Y.)

Industrial opportunities - offshore

International Nuclear Information System (INIS)

Gerrits, D.J.

1998-01-01

Industrial opportunities available in the Canadian offshore petroleum industry are discussed. Oil has been produced offshore from Nova Scotia since 1992, and offshore from Newfoundland since 1997. Special needs that must be addressed in offshore operations in eastern Canada such as the cold North Atlantic environment, isolation, logistics, safety, and quality assurance, are examined. The most obvious opportunities lie with the designing, building and installing the facilities needed to extract oil and gas from beneath the sea floor and transport it to market. However, there are also opportunities in designing and fabricating clothing, customized food containers and other equipment for offshore needs. Short term opportunities also exist in the decommissioning of depleted production fields and their facilities. One of the greatest obstacles facing new entrants into the offshore oil and gas industry is the lack of a track record. To meet this challenge, the ability to seek out partners to pursue local and international opportunities through joint ventures, strategic alliances and technology sharing partnering arrangements is of great importance. It may be the difference between success and failure. 6 figs

Floating polygon soup

OpenAIRE

Colleu , Thomas; Morin , Luce; Pateux , Stéphane; Labit , Claude

2011-01-01

International audience; This paper presents a new representation called floating polygon soup for applications like 3DTV and FTV (Free Viewpoint Television). This representation is based on 3D polygons and takes as input MVD data. It extends the previously proposed polygon soup representation which is appropriate for both compression, transmission and rendering stages. The floating polygon soup conserves these advantages while also taking into account misalignments at the view synthesis stage...

Have Floating Rates Been a Success?

Science.gov (United States)

Higham, David

1983-01-01

Floating exchange rates have not lived up to all expectations, but neither have they performed as badly as some critics have suggested. Examined are the impact of floating rates on balance of payments adjustment, domestic economic policy, and inflation and the claim that floating rates have displayed excessive fluctuations. (Author/RM)

Huge maternal hydronephrosis: a rare complication in pregnancy.

Science.gov (United States)

Peng, Hsiu-Huei; Wang, Chin-Jung; Yen, Chih-Feng; Chou, Chien-Chung; Lee, Chyi-Long

2003-06-10

A huge maternal hydronephrosis is uncommon in pregnancy and might be mistaken as a pelvic mass. A 21-year-old primigravida was noted at 25th week of gestation to have a visible bulging mass on her left flank. The mass was originally mistaken as a large ovarian cyst but later proved to be a huge hydronephrosis. Retrograde insertion of ureteroscope and a ureteric stent failed, so we performed repeated ultrasound-guided needle aspiration to decompress the huge hydronephrosis, which enabled the patient to proceed to a successful term vaginal delivery. Nephrectomy was performed after delivery and proved the diagnosis of congenital ureteropelvic junction obstruction.

From Offshoring to Backshoring

DEFF Research Database (Denmark)

Slepniov, Dmitrij; Madsen, Erik Skov

2015-01-01

The purpose of this paper is to examine the evolution of offshoring over time. The paper employs qualitative methodology and on the basis of two case studies of Danish companies, it develops a framework conceptualizing the stages of offshoring and highlights the factors driving the transition...... between these stages. The framework challenges the linear nature of offshoring and proposes the existence of ‘the pendulum effect’. The pendulum effect suggests that the modes of offshoring (i.e. captive and non-captive) and geographies of offshoring (i.e. home and abroad) are not static; rather...

Too much or too little of R&D offshoring : The impact of captive offshoring and contract offshoring on innovation performance

NARCIS (Netherlands)

Steinberg, Philip; Procher, Vivien D.; Urbig, Diemo

2017-01-01

Innovating firms may acquire foreign knowledge and improve their innovation performance by offshoring their R&D activities to their own foreign affiliates (captive offshoring) as well as by contracting out their R&D to external foreign parties (contract offshoring). This study examines the impact of

Offshore nuclear installations

International Nuclear Information System (INIS)

Albano, R.

1976-01-01

It is possible now to foresee the creation of nuclear power plants on floating or fixed islands although from the safety viewpoint, floating islands are preferable. The definition of the legal nature of artificial islands raises a first problem insofar as artificial islands are neither islands nor ships. Furthermore, their statute would differ according to whether they were sited in territorial seas or in the new 'economic zones'. This leads to consideration of the applicability of Italian maritime legislation to nuclear power plants on floating islands without setting aside that of international regulations on radioactive maritime pollution. (N.E.A.) [fr

Safety in offshore engineering an academic course covering safety in offshore wind

NARCIS (Netherlands)

Cerda Salzmann, D.J.

2011-01-01

Offshore projects are known for their challenging conditions, generally leading to high risks. Therefore no offshore project can go without a continuous and extensive assessment on safety issues. The Delft University of Technology is currently developing a course "Safety in Offshore Engineering"

A new assessment of floating exchange rates

OpenAIRE

Waimann, D. R.

1981-01-01

The switch to floating exchange rates during the 1970s has given economists the first comprehensive opportunity to assess the arguments for and against floating. Much new work has been done on various aspects of floating exchange rate behaviour. This article attempts a limited survey of the evidence concerning two important issues—whether floating exchange rates are inherently unstable and whether they harm international trade.

Offshore in depth

Energy Technology Data Exchange (ETDEWEB)

Ebdon, J F

1968-08-01

The world-wide scope of offshore areas is discussed. Offshore areas of the U.S. and the world are where one of the ''hottest'' hydrocarbon booms--drilling, production, and pipelining--are in action today. Most of the current activity in offshore exploration and drilling is crude oil directed. However, big non-associated natural gas finds have been made. Additionally, for every barrel of crude oil produced, either or both associated natural gas and dissolved natural gas are produced in some varying ratio as casinghead gas. Thus, with worldwide production of some 2.5-million bbl of crude oil per day from offshore areas of Free-World countries, there are vast volumes of casinghead natural gas produced, over and above that produced from non-associated natural gas wells to the seaward of land masses. If offshore gas of any classification is produced in commercial volumes close to onshore population centers, then the possibility of marketing is fairly good. If remote from population centers, it is usually flared or shut-in. The development of gas liquefaction and cryogenic tankers has started, but international ocean traffic in LNG is still in its infancy. Current offshore gas pipelines are described.

The floating knee

DEFF Research Database (Denmark)

Muñoz Vives, Josep; Bel, Jean-Christophe; Capel Agundez, Arantxa

2016-01-01

In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions...... fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra......-articular fracture which gives the worst prognosis for this type of lesion. Cite this article: Muñoz Vives K, Bel J-C, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis, T. The floating knee.EFORT Open Rev2016;1:375-382. DOI: 10.1302/2058-5241.1.000042....

Control development for floating wind

International Nuclear Information System (INIS)

Savenije, Feike; Peeringa, Johan

2014-01-01

Control of a floating wind turbine has proven to be challenging, but essential for lowering the cost of floating wind energy. Topic of a recent joint R and D project by GustoMSC, MARIN and ECN, is the concept design and verification with coupled simulations and model tests of the GustoMSC Tri-Floater. Only using an integral design approach, including mooring and control design, a cost effective system can be obtained. In this project, ECN developed a general floating wind turbine control strategy and applied this in a case study to the GustoMSC Tri-Floater and the OC3Hywind spar, both equipped with the NREL 5MW RWT. The designed controller ensures stable operation, while maintaining proper speed and power regulation. The motions of the floating support are reduced and substantial load reduction has been achieved

A preliminary analysis of floating production storage and offloading facilities with gas liquefaction processes

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; Carranza-Sánchez, Yamid Alberto; Junior, Silvio de Oliveira

2016-01-01

Floating, production, storage and offloading (FPSO) plants are facilities used in upstream petroleum processing. They have gained interest because they are more flexible than conventional plants and can be used for producing oil and gas in deep-water fields. In general, gas export is challenging...... because of the lack of infrastructure in remote locations. The present work investigates the possibility of integrating liquefaction processes on such facilities, considering two mixed-refrigerant and two expansion-based processes suitable for offshore applications. Two FPSO configurations are considered...... in this work, and they were suggested by Brazilian operators for fields processing natural gas with moderate to high content of carbon dioxide. The performance of the combined systems is analysed by conducting energy and exergy analyses. The integration of gas liquefaction results in greater power consumption...

Offshore risk assessment

CERN Document Server

Vinnem, Jan-Erik

2014-01-01

  Offshore Risk Assessment was the first book to deal with quantified risk assessment (QRA) as applied specifically to offshore installations and operations. Risk assessment techniques have been used for more than three decades in the offshore oil and gas industry, and their use is set to expand increasingly as the industry moves into new areas and faces new challenges in older regions.   This updated and expanded third edition has been informed by a major R&D program on offshore risk assessment in Norway and summarizes research from 2006 to the present day. Rooted with a thorough discussion of risk metrics and risk analysis methodology,  subsequent chapters are devoted to analytical approaches to escalation, escape, evacuation and rescue analysis of safety and emergency systems.   Separate chapters analyze the main hazards of offshore structures: fire, explosion, collision, and falling objects as well as structural and marine hazards. Risk mitigation and control are discussed, as well as an illustrat...

Offshore wind energy developments

DEFF Research Database (Denmark)

Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu

2014-01-01

This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services....

Model for economical analysis of oil and gas deepwater production concepts : Comparisons of life cycle cost of subsea production systems vs. floating structures with dry wellheads.

OpenAIRE

Romero Mata, Omar

2010-01-01

Master's thesis in Offshore technology The scope of the work was to create a model that will allow the comparison of Life Cycle Costs (LCC) for subsea production systems and floating structures with dry wellheads for the Mexican territorial waters of the Gulf of Mexico. To give validity to the model, an empirical comparison on the resulting recovery factor based on data of the US Gulf of Mexico was included. This comparison is intended to answer ¿Is there a significant diffe...

14 CFR 25.753 - Main float design.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float design...

Evaluating stress analysis and failure criteria for offshore structures for Pechora Sea conditions

Science.gov (United States)

Nesic, S.; Donskoy, Y.; Zolotukhin, A.

2017-12-01

Development of Arctic hydrocarbon resources has faced many challenges due to sensitive environmental conditions including low temperatures, ice cover and terrestrial permafrost and extreme seasonal variation in sunlight. Russian offshore field development in Arctic region is usually associated with annual ice cover, which can cause serious damage on the offshore platforms. The Pechora Sea has claimed as one of the most perspective oil and gas region of the Russian Arctic with seven discovered oil and gas fields and several dozens of structures. Our rough assessment, based on in-place hydrocarbon volumes and recovery factor evaluation concept, indicates that Pechora Sea alone has in-place volumes amounting to ca. 20 billion barrel oil equivalent (BOE). This quantity is enough to secure produced volumes by 2040 exceeding 3 billion BOE [1] that indicates huge resource potential of the region. The environmental conditions are primarily function of water dynamics and ice cover. The sea is covered by the ice for greatest part of the year. In this article, the ice load simulations were performed using explicit dynamic analysis system in ANSYS software to determine best shape and size of an offshore platform for the Pechora Sea ice conditions. Different gravity based structures (GBS) were analyzed: artificial island, hollow cylindrical and conical concrete structures and four-leg GBS. Relationships between the stress, deformations and time were analyzed and important observations from the simulation results were a basis for selecting the most preferable structures.

Domestic R&D and Offshoring

DEFF Research Database (Denmark)

Junge, Martin; Sørensen, Anders

2017-01-01

survey and register data. No evidence is found for a lower probability of own R&D after offshoring takes place compared to before. Moreover, offshoring does not lead to lower R&D intensity in general. However, firms that offshore R&D activity have larger R&D intensity after offshoring has taken place...

Current trends in offshore technology

International Nuclear Information System (INIS)

Korsgaard, J.

1994-01-01

Although this is a technical symposium concerning advances in the technology of producing oil and gas offshore, a keynote address would not be complete without mentioning non-technical factors which are extremely important for the business of producing oil and gas offshore. These are political factors and economic factors. Offshore operations are an easy target for political forces that are opposed to marine operations involving the production and transfer of hydrocarbons. For example, the oil pollution act of 1990 was a reaction to the Exxon Valdez grounding in Alaska and this act has added significantly to the risk and cost of operating offshore. Another example of this is that it is becoming more and more difficult to dispose of produced water offshore. Producing oil and gas offshore is a business that competes with other energy sources such as coal and oil and gas from wells on land. The offshore oil can only compete with these other resources by providing the same product at a competitive price. Since offshore operations are inherently more costly than land operations, the offshore oil field or gas field must be significantly larger than a land field in order to be produced. Also the offshore oil field or gas field is more susceptible to environmental risks from weather. On a more positive note, there are technical developments which are taking place and have continuously taken place to make offshore oil and gas both more economic and safer to produce. These developments are briefly discussed

Offshoring and International Competitiveness

DEFF Research Database (Denmark)

Ørberg Jensen, Peter D.; Pedersen, Torben

2012-01-01

During the past decade, offshoring has become an established business practice. Yet it is still more common to offshore less advanced tasks compared with offshoring more advanced tasks, i.e., tasks closer to the core activities of the firm. The latter is a new phenomenon which raises many new iss...

Offshore Transmission Technology

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-10-15

The purpose of this document is to give an overview of offshore electricity transmission technologies. In particular this document is concerned with the use of High Voltage Direct Current (HVDC) systems and more specifically with the development of Voltage Source Converter (VSC) technology. This report outlines the current state of the main technology groups required for offshore HVDC transmission as well as giving examples of offshore projects (both current and future). Finally some indications of likely unit costs for HV assets are given.

Outsourcing software development offshore making IT work

CERN Document Server

Gold, Tandy

2004-01-01

THE OFFSHORE IMPERATIVECrunching the Offshore Numbers: What the Financials PortendWelcome to the Definitive Guide on Offshore OutsourcingSetting the Stage: The Compelling Offshore StoryOffshore Outsourcing versus Traditional IT OutsourcingChallenges of Offshore OutsourcingChapter SummaryGetting Started in OffshoreExecutive Support and Communications: The Key to SuccessA Look at an Example of Enlightened Leadership: Handling Employee Impact at a Northeast Utilities CompanyWell-Planned and Executed Communications: A Critical Success Factor for Offshore Program InitiationEstablishing the Offshore

Off-shore Wind Atlas of the Central Aegean Sea: A simple comparison of NCEP/NCAR RE-analysis data, QuickSCAT and ENVISAT Synthetic Aperture Radar (SAR) by use of Wind Atlas Method

DEFF Research Database (Denmark)

Bingöl, Ferhat; Hasager, Charlotte Bay; Karagali, Ioanna

2012-01-01

model results). Unfortunately all of these methods are still under development and do not provide data acceptable for bankable wind assessment reports. On the other hand, they give good indications of the geographical distribution of the wind resources and that is very useful for decision making...... to high costs, but with the new developments in floating turbine design, it seems that offshore wind parks in deep waters will also be a possibility in the future. Whether on-shore or offshore, the first step of a site assessment is to estimate the wind resources. Usually well-known conventional methods...... are used to produce estimates of wind resources by means of at least one year data from a single or multiple points on the terrain. This criterion is dicult to satisfy in offshore locations where measurements are costly and sparse. Therefore other methods are required (e.g satellite imagery or reanalysis...

Offshore wind energy prospects

International Nuclear Information System (INIS)

Gaudiosi, Gaetano

1999-01-01

In last two years offshore wind energy is becoming a focal point of national and non national organisations particularly after the limitations of fossil fuel consumption, adopted by many developed countries after Kyoto conference at the end of 1997 on global climate change. North Europe is particularly interested in offshore for the limited land areas still available, due to the intensive use of its territory and its today high wind capacity. Really the total wind capacity in Europe could increase from the 1997 value of 4450 MW up to 40 000 MW within 2010, according the White Paper 1997 of the European Commission; a significant percentage (25%) could be sited offshore up to 10 000 MW, because of close saturation of the land sites at that time. World wind capacity could increase from the 1997 value of 7200 MW up to 60 000 MW within 2010 with a good percentage (20%) offshore 12 000 MW. In last seven years wind capacity in shallow water of coastal areas has reached 34 MW. Five wind farms are functioning in the internal seas of Netherlands, Denmark, Sweden; however such siting is mostly to be considered as semi-offshore condition. Wind farms in real offshore sites, open seas with waves and water depth over 10 m, are now proposed in North Sea at 10-20 km off the coasts of Netherlands, Denmark using large size wind turbine (1-2 MW). In 1997 an offshore proposal was supported in Netherlands by Greenpeace after the OWEMES '97 seminar, held in Italy on offshore wind in the spring 1997. A review is presented in the paper of European offshore wind programs with trends in technology, economics and siting effects. (Author)

Huge Thornwaldt's Cyst: A Case Report

Directory of Open Access Journals (Sweden)

Jia-Hau Lin

2006-10-01

Full Text Available Thornwaldt's bursa, also known as nasopharyngeal bursa, is a recess in the midline of the nasopharynx that is produced by persistent notochord remnants. If its opening becomes obstructed, possibly due to infection or a complication from adenoidectomy, a Thornwaldt's cyst might develop. Here, we present a 53-year-old man who complained of nasal obstruction that had progressed for 1 year. Nasopharyngoscopy showed a huge nasopharyngeal mass. Thornwaldt's cyst was suspected. Magnetic resonance imaging showed a lesion measuring 3.6 × 3.4 cm, intermediate on T1-weighted and high signal intensity on T2-weighted imaging, neither bony destruction nor connection to the brain. The patient underwent endoscopic surgery for this huge mass. Afterwards, his symptoms improved significantly. We present the treatment and differential diagnosis of a nasopharyngeal cyst.

Outcomes of the DeepWind conceptual design

NARCIS (Netherlands)

Paulsen, US; Borg, M.; Madsen, HA; Pedersen, TF; Hattel, J; Ritchie, E.; Simao Ferreira, C.; Svendsen, H.; Berthelsen, P.A.; Smadja, C.

2015-01-01

DeepWind has been presented as a novel floating offshore wind turbine concept with cost reduction potentials. Twelve international partners developed a Darrieus type floating turbine with new materials and technologies for deep-sea offshore environment. This paper summarizes results of the 5 MW

Huge magnetoresistance effect of highly oriented pyrolytic graphite

International Nuclear Information System (INIS)

Du Youwei; Wang Zhiming; Ni Gang; Xing Dingyu; Xu Qingyu

2004-01-01

Graphite is a quasi-two-dimensional semimetal. However, for usual graphite the magnetoresistance is not so high due to its small crystal size and no preferred orientation. Huge positive magnetoresistance up to 85300% at 4.2 K and 4950% at 300 K under 8.15 T magnetic field was found in highly oriented pyrolytic graphite. The mechanism of huge positive magnetoresistance is not only due to ordinary magnetoresistance but also due to magnetic-field-driven semimetal-insulator transition

Assessing offshore wind potential

International Nuclear Information System (INIS)

Adelaja, Adesoji; McKeown, Charles; Calnin, Benjamin; Hailu, Yohannes

2012-01-01

Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.

Wind energy in offshore grids

DEFF Research Database (Denmark)

Schröder, Sascha Thorsten

special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment...... and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid......This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids...

The Hidden Costs of Offshoring

DEFF Research Database (Denmark)

Møller Larsen, Marcus; Manning, Stephan; Pedersen, Torben

2011-01-01

of offshoring. Specifically, we propose that hidden costs can be explained by the combination of increasing structural, operational and social complexity of offshoring activities. In addition, we suggest that firm orientation towards organizational design as part of an offshoring strategy and offshoring......This study seeks to explain hidden costs of offshoring, i.e. unexpected costs resulting from the relocation of business tasks and activities outside the home country. We develop a model that highlights the role of complexity, design orientation and experience in explaining hidden costs...... experience moderate the relationship between complexity and hidden costs negatively i.e. reduces the cost generating impact of complexity. We develop three hypotheses and test them on comprehensive data from the Offshoring Research Network (ORN). In general, we find support for our hypotheses. A key result...

Offshore Wind Energy Market Overview (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Baring-Gould, I.

2013-07-01

This presentation describes the current international market conditions regarding offshore wind, including the breakdown of installation costs, how to reduce costs, and the physical siting considerations considered when planning offshore wind construction. The presentation offers several examples of international existing and planned offshore wind farm sites and compares existing international offshore resources with U.S. resources. The presentation covers future offshore wind trends and cites some challenges that the United States must overcome before it will be able to fully develop offshore wind sites.

Offshore investments-cui prodis? Schrodinger's cat in offshore financing: Both alive and dead

Directory of Open Access Journals (Sweden)

Stepuk Anna

2014-01-01

Full Text Available Trends of FDI in offshore tax havens were compared to efforts and efficiency of regulatory authorities to prevent money laundering. Based on available data it was stated that current position in offshore FDI stays alive and officially dead at the same time, keeping the balance of interests for the main stakeholders: corporations, authorities and financial institutes support further offshore investments. Analysis based on volumes of trade and financial transactions between offshore centers, developed and developing countries. As a result withdrawal of financial resources from the developing countries degrades social capital funding and supports corruption growth.

14 CFR 29.757 - Hull and auxiliary float strength.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand the...

Comparison of the Experimental and Numerical Results of Modelling a 32-Oscillating Water Column (OWC, V-Shaped Floating Wave Energy Converter

Directory of Open Access Journals (Sweden)

John V. Ringwood

2013-08-01

Full Text Available Combining offshore wind and wave energy converting apparatuses presents a number of potentially advantageous synergies. To facilitate the development of a proposed floating platform combining these two technologies, proof of concept scale model testing on the wave energy converting component of this platform has been conducted. The wave energy component is based on the well-established concept of the oscillating water column. A numerical model of this component has been developed in the frequency domain, and the work presented here concerns the results of this modelling and testing. The results of both are compared to assess the validity and usefulness of the numerical model.

Offshoring research directions

NARCIS (Netherlands)

Velthuijsen, Hugo

2012-01-01

Outsourcing and offshoring provide companies with ways to achieve their business objectives better or more cost effectively or despite a shortage of specific resources. From a research point of view, outsourcing and offshoring have mostly been studied as something that large companies do, not small

Strength Tests on Hulls and Floats

Science.gov (United States)

Matthaes, K

1942-01-01

The present report deals with strength tests on hulls and floats intended in part for the collection of construction data for the design of these components and in part for the stress analysis of the finished hulls and floats.

National Offshore Wind Energy Grid Interconnection Study

Energy Technology Data Exchange (ETDEWEB)

Daniel, John P. [ABB Inc; Liu, Shu [ABB Inc; Ibanez, Eduardo [National Renewable Energy Laboratory; Pennock, Ken [AWS Truepower; Reed, Greg [University of Pittsburgh; Hanes, Spencer [Duke Energy

2014-07-30

The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

Offshore investments: Denmark shows the way

International Nuclear Information System (INIS)

Anon.

1998-01-01

This article presents an overview of the use of wind power in Denmark and discusses the tremendous growth in the manufacture of wind turbines since 1981 with Denmark holding some 60% of the worlds' wind turbine market. The move to offshore wind farms is explained in terms of the shortage of land and the quality of the offshore wind, and details of the Tuno Knob pilot offshore wind farm are given. Offshore wind power in Europe, the challenges to offshore operations, the costs involved, environmental effects of the use of offshore wind, and the growing amount of wind power capacity are discussed

WindWaveFloat (WWF): Final Scientific Report

Energy Technology Data Exchange (ETDEWEB)

Weinstein, Alla; Roddier, Dominique; Banister, Kevin

2012-03-30

Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

Global offshore pipeline markets

International Nuclear Information System (INIS)

Knight, R.; Parsons, B.

2001-01-01

In this article, two experts forecast a recovery in the offshore pipeline market followed by accelerating growth. A number of clearly definable macro trends are affecting the world offshore oil and gas industry and will be of considerable significance to the offshore pipelines industry. The authors' view is of markets that show every chance of enjoying long-term growth prospects driven by the fundamentals of a continuing increase in demand for offshore oil and gas. The offshore industry however has a highly cyclical nature, due to the impact of variations in oil and gas prices and the differing state of maturity of individual regions. Therefore those companies that are able to offer the widest range of pipe types and diameters and methods of installation across the greatest range of geographic markets are likely to prosper most. Thus, this continues to be a market best suited to those able to operate on a global scale and make a corporate commitment measured in decades

Panorama 2012 - Offshore hydrocarbons

International Nuclear Information System (INIS)

Serbutoviez, Sylvain

2011-12-01

Technological progress is enabling production from offshore oil and gas fields at increasingly ambitious depths (3, 000 metres). Investment in offshore production is running at around $100 billion per year, accounting for one-fifth of all investment in oil exploration and development worldwide. However, the global economic crisis that broke at the end of 2008 and the accident involving the Macondo well temporarily disrupted the race to deep offshore technology. (author)

Floating Offshore Wind in Oregon: Potential for Jobs and Economic Impacts in Oregon Coastal Counties from Two Future Scenarios

Energy Technology Data Exchange (ETDEWEB)

Jimenez, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-07-01

This analysis examines the employment and potential economic impacts of large-scale deployment of offshore wind technology off the coast of Oregon. This analysis examines impacts within the seven Oregon coastal counties: Clatsop, Tillamook, Lincoln, Lane, Douglas, Coos, and Curry. The impacts highlighted here can be used in county, state, and regional planning discussions and can be scaled to get a general sense of the economic development opportunities associated with other deployment scenarios.

Stress analysis and mitigation measures for floating pipeline

Science.gov (United States)

Wenpeng, Guo; Yuqing, Liu; Chao, Li

2017-03-01

Pipeline-floating is a kind of accident with contingency and uncertainty associated to natural gas pipeline occurring during rainy season, which is significantly harmful to the safety of pipeline. Treatment measures against pipeline floating accident are summarized in this paper on the basis of practical project cases. Stress states of pipeline upon floating are analyzed by means of Finite Element Calculation method. The effectiveness of prevention ways and subsequent mitigation measures upon pipeline-floating are verified for giving guidance to the mitigation of such accidents.

Offshore industry: medical emergency response in the offshore oil and gas industry.

Science.gov (United States)

Ponsonby, Will; Mika, Frano; Irons, Greg

2009-08-01

The hunt for oil and gas has taken workers into new more distant locations including those offshore. The remoteness of the offshore platforms and vessels coupled with the potential risk of being cut off by bad weather presents particular challenges for medical emergency response (MER). Firstly to define the challenges for MER in terms of locations, population and epidemiology of injuries and illnesses in the offshore environment. Secondly to give examples of legal requirements and industry standards to manage MER. Thirdly to look at existing and emerging practice to manage these challenges. A review of published literature was supplemented with a summary of current practice in the industry. Medical professionals (medics) working offshore on installations and vessels are primarily responsible for the medical care of the workers. The medics have clinics with suitable medical equipment for managing emergencies as well as providing limited primary care. Some countries have legislation that stipulate minimum requirements. Where there is no national legislation, industry and company guidance is used to define the MER standards. Supervision of the offshore medics is often provided by doctors on shore via radio and phone links. These methods of communication are now being augmented with more sophisticated telemedicine solutions such as the Internet and live video links. These newer solutions allow for prompt high-quality care and provide the scope for a variety of new treatment options to be available for the offshore workforce.

Uncovering the Hidden Costs of Offshoring

DEFF Research Database (Denmark)

Larsen, Marcus M.; Manning, Stephan; Pedersen, Torben

2013-01-01

This study investigates estimation errors due to hidden costs—the costs of implementation that are neglected in strategic decision-making processes—in the context of services offshoring. Based on data from the Offshoring Research Network, we find that decision makers are more likely to make cost......-estimation errors given increasing configuration and task complexity in captive offshoring and offshore outsourcing, respectively. Moreover, we show that experience and a strong orientation toward organizational design in the offshoring strategy reduce the cost-estimation errors that follow from complexity. Our...

Tidal influence on offshore wind fields and resource predictions[Efficient Development of Offshore Windfarms

Energy Technology Data Exchange (ETDEWEB)

Khan, D. [Entec UK Ltd., Doherty Innovation Centre, Penicuik (United Kingdom); Infield, D. [Loughborough Univ., Centre for Renewable Energy Systems Tecnology, Loughborough (United Kingdom)

2002-03-01

The rise and fall of the sea surface due to tides effectively moves an offshore wind turbine hub through the wind shear profile. This effect is quantified using measured data from 3 offshore UK sites. Statistical evidence of the influence of tide on mean wind speed and turbulence is presented. The implications of this effect for predicting offshore wind resource are outlined. (au)

Dispersion measurements from Sofar floats on the Iberian Abyssal plain

International Nuclear Information System (INIS)

Rees, J.M.; Gmitrowicz, M.

1989-01-01

Tracks of SOFAR floats launched on the Iberian Abyssal Plain are presented. The floats were launched in two groups in early October 1984 and mid-February 1985 to a nominal depth of 2500 m. Of these floats, 4 from the first deployment and 2 from the second functioned properly. Float signals were recorded by four autonomous listening stations at a depth of 1900 m. These preliminary results show the tracks of floats up to July 1986 and represent 3600 float days of information. The main task of the experiment was to especially study the dispersion of radioactive substances

Healthy offshore workforce? A qualitative study on offshore wind employees' occupational strain, health, and coping.

Science.gov (United States)

Mette, Janika; Velasco Garrido, Marcial; Harth, Volker; Preisser, Alexandra M; Mache, Stefanie

2018-01-23

Offshore work has been described as demanding and stressful. Despite this, evidence regarding the occupational strain, health, and coping behaviors of workers in the growing offshore wind industry in Germany is still limited. The purpose of our study was to explore offshore wind employees' perceptions of occupational strain and health, and to investigate their strategies for dealing with the demands of offshore work. We conducted 21 semi-structured telephone interviews with employees in the German offshore wind industry. The interviews were transcribed and analyzed in a deductive-inductive approach following Mayring's qualitative content analysis. Workers generally reported good mental and physical health. However, they also stated perceptions of stress at work, fatigue, difficulties detaching from work, and sleeping problems, all to varying extents. In addition, physical health impairment in relation to offshore work, e.g. musculoskeletal and gastrointestinal complaints, was documented. Employees described different strategies for coping with their job demands. The strategies comprised of both problem and emotion-focused approaches, and were classified as either work-related, health-related, or related to seeking social support. Our study is the first to investigate the occupational strain, health, and coping of workers in the expanding German offshore wind industry. The results offer new insights that can be utilized for future research in this field. In terms of practical implications, the findings suggest that measures should be carried out aimed at reducing occupational strain and health impairment among offshore wind workers. In addition, interventions should be initiated that foster offshore wind workers' health and empower them to further expand on effective coping strategies at their workplace.

Co-sourcing in software development offshoring

DEFF Research Database (Denmark)

Schlichter, Bjarne Rerup; Persson, John Stouby

2013-01-01

Software development projects are increasingly geographical distributed with offshoring, which introduce complex risks that can lead to project failure. Co-sourcing is a highly integrative and cohesive approach, seen successful, to software development offshoring. However, research of how co......-sourcing shapes the perception and alleviation of common offshoring risks is limited. We present a case study of how a certified CMMI-level 5 Danish software supplier approaches these risks in offshore co-sourcing. The paper explains how common offshoring risks are perceived and alleviated when adopting the co...

OFFSHORING FOR SUSTAINABLE VALUE MANAGEMENT

Directory of Open Access Journals (Sweden)

Thaddeus Oforegbunam Ebiringa

2014-05-01

Full Text Available This paper evaluates offshoring as a strategic value management initiative using Cadbury Nigeria Plc as a case study. Through offshoring risks associated with inventory holding are hedged. A comparative analysis of in-house and offshored cost profiles as well as critical risk factors that affect firm value are evaluated. The result shows that offshoring led to immediate costs saving, freeing of funds previously held in inventory for other working capital investments as well as profitability for vendors. However, aside financial benefits to partners, it leads to increased stakeholders awareness, shared values, partnerships, teamwork and risk mitigation. It therefore follows that for sustainability of financial benefits of offshoring, concerted effort must be made by partners to ensure that critical drivers of value management are not compromised.

Validation of salinity data from ARGO floats: Comparison between the older ARGO floats and that of later deployments

Digital Repository Service at National Institute of Oceanography (India)

Youn, Y.-H.; Lee, H.; Chang, Y.-S.; Pankajakshan, T.

Continued observation of ARGO floats or years (about 4 years) makes the conductivity sensor more vulnerable to fouling by marine life and associated drift in salinity measurements. In this paper, we address this issue by making use of floats...

Huge interparietal posterior fontanel meningohydroencephalocele

Directory of Open Access Journals (Sweden)

Jorge Félix Companioni Rosildo

2015-03-01

Full Text Available Congenital encephalocele is a neural tube defect characterized by a sac-like protrusion of the brain, meninges, and other intracranial structures through the skull, which is caused by an embryonic development abnormality. The most common location is at the occipital bone, and its incidence varies according to different world regions. We report a case of an 1-month and 7-day-old male child with a huge interparietal-posterior fontanel meningohydroencephalocele, a rare occurrence. Physical examination and volumetric computed tomography were diagnostic. The encephalocele was surgically resected. Intradural and extradural approaches were performed; the bone defect was not primarily closed. Two days after surgery, the patient developed hydrocephaly requiring ventriculoperitoneal shunting. The surgical treatment of the meningohydroencephalocele of the interparietal-posterior fontanel may be accompanied by technical challenges and followed by complications due to the presence of large blood vessels under the overlying skin. In these cases, huge sacs herniate through large bone defects including meninges, brain, and blood vessels. The latter present communication with the superior sagittal sinus and ventricular system. A favorable surgical outcome generally follows an accurate strategy taking into account individual features of the lesion.

Offshore oil and gas and offshore wind power - different in terms of safety.?; Offshore Oel and Gas und Offshore Wind - mit Sicherheit ''anders''.?

Energy Technology Data Exchange (ETDEWEB)

Weise, F.; Tatulinski, M. [DNV GL - Oil and Gas Germany, Hamburg (Germany)

2014-07-01

Safety standards in the oil and gas industry have risen to a high level over the past decades, driven in part by momentous accidents. Furthermore, an expanded framework has recently been defined through the new EU Offshore Safety Directive, which in Germany is still in the process of its transposition into national law. The installation of offshore wind farms in the North and Baltic Sea has within the shortest of time brought forth an entirely new branch of industry, most of whose players have no significant experience with offshore operations. One of the greatest challenges is the working environment, which is being approached in different ways by those involved. The supervisory authorities responsible are only just beginning to develop the competence required for their tasks, with the effect that regulations pertaining to onshore operations are often simply adopted as they are. This is in some cases impacting on the oil and gas industry, as is discussed in the present lecture. [German] Die Oel und Gas Industrie hat in den vergangen Jahrzehnten einen hohen Sicherheitsstandard entwickelt, teilweise getrieben durch signifikante Unfallereignisse. Aktuell wurde zudem mit der neuen EU-Offshore Richtlinie ein erweiterter Rahmen definiert, der sich in Deutschland noch in der gesetzgeberischen Umsetzung befindet. Durch die Installation von Offshore-Windparks in der Nord- und Ostsee ist innerhalb kuerzester Zeit zusaetzlich ein neuer Industriebereich entstanden, dessen Marktteilnehmer mehrheitlich nicht ueber signifikante Offshore-Erfahrung verfuegen. Insbesondere das Arbeitsumfeld stellt dabei eine Herausforderung dar, die von den Beteiligten unterschiedlich geloest wird. Ferner beginnen auch die verantwortlichen Aufsichtsbehoerden erst mit dem Aufbau entsprechender Kompetenzen, so dass vielfach auch Regelungen aus dem Onshore-Bereich uebertragen werden. Dies fuehrt teilweise zu Auswirkungen auf die Oel- und Gasindustrie, die im Rahmen dieses Vortrages diskutiert werden.

Dutch offshore suppliers in confident mood

International Nuclear Information System (INIS)

Beudel, M.

1998-01-01

A series of linked articles discusses the current state of the Netherland's offshore industry. Reduced taxes, and availability of exploration licenses has meant that explorers and producers are drawn to the small size, but frequent yield explorations on Holland's continental shelf. The excellent operation record of Rotterdam's Verolme Botlek yard; for repair and maintenance of offshore platforms and associated plant, is explored as the facility plans to diversify into newbuilding. The construction of an offshore basin designed for the hydrodynamic testing of offshore plant intended for deepwater use is described. The Netherlands maritime research institute (Marin) aims to stay at the forefront of offshore research and development with this new facility. Other articles cover pipe tensioning, new large linear winches and innovations in offshore drilling and production. (UK)

Influence of different types of low substituted hydroxypropyl cellulose on tableting, disintegration, and floating behaviour of floating drug delivery systems.

Science.gov (United States)

Diós, Péter; Pernecker, Tivadar; Nagy, Sándor; Pál, Szilárd; Dévay, Attila

2015-11-01

The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X 1) and L-HPC (X2 ) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X 3). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms.

Floating on the margins [Environmental issues for floating production platforms

International Nuclear Information System (INIS)

Grimshaw, R.

1997-01-01

The main environmental issues challenging oilfield development using floating production platforms in harsh environments such as the Atlantic frontier are discussed. These fall into two broad categories -operating conditions and biological disturbance. Particular combinations of wind and currents can lead to extremely difficult operating conditions through which floating units are expected to maintain production for economic reasons. This imposes stringent conditions on the design and construction of tanker hulls and of risers to enable them to remain connected at all times. Prediction of wind and wave forces is a crucial element of operational and safety planning. Fauna in seabed sediments disturbed by pipeline laying often relocate but some seeding back of colonies may be required in hard rock areas. Migration routes for cetaceans and the feeding grounds of marine birds must be considered and the potential long and short term damage to commercial fisheries through discharges need to be assessed. A significant risk is the interaction of sub-sea facilities and fishing gear and oil spills. Operational and accidental discharges of production chemicals, produced water containing oil, deck drainage and treated sewage, and discharges to air from flaring and utility exhausts are of major environmental concern calling for mitigation and protection measures and contingency plans. Some of the environmental issues associated with decommissioning are reduced by the use of floating platforms but there are global and national regulations governing the process. (UK)

Offshoring R&D

DEFF Research Database (Denmark)

Hansen, Zaza Nadja Lee; Rasmussen, Lauge Baungaard

2010-01-01

Companies are increasingly offshoring R&D activities. Many firms, however, experience difficulties related to virtual teamwork across cultures and time zones. The research question is: How does increasing R&D offshoring impact transparency of communication structures and knowledge sharing? Using...... case studies from Danish multinational corporations with R&D activities in China, India or Eastern Europe this paper analyses the impact observed in these companies in regard to communication structures and knowledge sharing in management of offshored R&D activities. The findings show that companies...... attempt to increase transparency through formalisation of knowledge and clear communication structures. However, the influence of tacit knowledge, horizontal communication and culture seem largely overlooked. Therefore the authors suggest a context based approach to transparency accustomed...

Offshore Wind Energy Resource Assessment for Alaska

Energy Technology Data Exchange (ETDEWEB)

Doubrawa Moreira, Paula [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George N. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kilcher, Levi F. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Draxl, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lantz, Eric J. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2018-01-02

This report quantifies Alaska's offshore wind resource capacity while focusing on its unique nature. It is a supplement to the existing U.S. Offshore Wind Resource Assessment, which evaluated the offshore wind resource for all other U.S. states. Together, these reports provide the foundation for the nation's offshore wind value proposition. Both studies were developed by the National Renewable Energy Laboratory. The analysis presented herein represents the first quantitative evidence of the offshore wind energy potential of Alaska. The technical offshore wind resource area in Alaska is larger than the technical offshore resource area of all other coastal U.S. states combined. Despite the abundant wind resource available, significant challenges inhibit large-scale offshore wind deployment in Alaska, such as the remoteness of the resource, its distance from load centers, and the wealth of land available for onshore wind development. Throughout this report, the energy landscape of Alaska is reviewed and a resource assessment analysis is performed in terms of gross and technical offshore capacity and energy potential.

Proceedings of the ENDOW workshop 'Offshore wakes: Measurements and modelling[Efficient Development of Offshore Windfarms

Energy Technology Data Exchange (ETDEWEB)

Barthelmie, R.J. (ed.)

2002-03-01

The papers presented in these Proceedings are the result of a workshop held at Risoe National Laboratory on March 7 and 8 2002 entitled 'Offshore Wakes: Measurements and Modelling'. The Workshop was arranged to showcase results of the European Community supported project 'Efficient Development of Offshore Windfarms (ENDOW)' and featured a series of eight presentations discussing modelling of wakes and boundary layers, existing and new measurements from offshore wind farms and how these will be linked in a new design tool and applied at planned offshore wind farms. In addition seven invited presentations covered a range of relevant topics from analytical approaches to fatigue and extreme loads in wind turbine clusters, current wake modelling in WAsP, optimising power production at Arklow Bank, Particle Image Velocimetry study of a wind turbine wake in a yaw, offshore wind measurements in Massachusetts, accuracy of SODAR measurements for wind energy and tidal influence of offshore wind speeds and turbulence. (au)

Organizational Adaptation in Offshoring

DEFF Research Database (Denmark)

Geisler Asmussen, Christian; Møller Larsen, Marcus; Pedersen, Torben

2016-01-01

Offshoring offers managers the promise of substantial economic benefits, but also comes with the risk of increased complexity and coordination challenges. We argue that offshoring firms must accumulate architectural knowledge to keep the cost of coordination of the geographically separated activi...

Offshore wind development research.

Science.gov (United States)

2014-04-01

Offshore wind (OSW) development is a new undertaking in the US. This project is a response to : New Jerseys 2011 Energy Master Plan that envisions procuring 22.5% of the states power : originating from renewable sources by 2021. The Offshore Wi...

Offshore Fish Community: Ecological Interactions | Science ...

Science.gov (United States)

The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone. Bloater is abundant in the offshore zone but appears restricted to depths shallower than 150 m (Selgeby and Hoff 1996; Stockwell et al. 2010), although it occuppied greater depths several decades ago (Dryer 1966; Peck 1977). Shortjaw is relatively rare in the offshore zone (Hoff and Todd 2004; Gorman and Hoff 2009; Gorman and Todd 2007). Lake whitefish is also known to frequent bathymetric depths >100 m (Yule et al. 2008b). In this chapter, we develop a conceptual model of the offshore food web based on data collected during 2001-2005 and on inferences from species interactions known for the nearshore fish community. We then develop a framework for examination of energy and nutrient movements within the pelagic and benthic habitats of the offshore zone and across the offshore and nearshore zones. To document research results.

Offshore Wind Power Planning in Korea

DEFF Research Database (Denmark)

Seo, Chul Soo; Cha, Seung-Tae; Park, Sang Ho

2012-01-01

this possible, Korea has announced the National offshore power roadmap and is now in pursuit. However, large scale offshore wind farms can incur many problems, such as power quality problems, when connecting to a power system.[1][2] Thus, KEPCO is on the process of a research study to evaluate the effects...... that connecting offshore wind power generation to a power system has on the power system. This paper looks over offshore wind power planning in Korea and describes the development of impact assessment technology of offshore wind farms.......Wind power generation is globally recognized as the most universal and reliable form of renewable energy. Korea is currently depending mostly on coal and petroleum to generate electrical power and is now trying to replace them with renewable energy such as offshore wind power generation. To make...

Investigation of Tank 241-AW-104 Composite Floating Layer

Energy Technology Data Exchange (ETDEWEB)

Meznarich, H. K. [Washington River Protection Solutions LLC (WRPS), Richland, WA (United States); Bolling, S. D. [Washington River Protection Solutions LLC (WRPS), Richland, WA (United States); Lachut, J. S. [Washington River Protection Solutions LLC (WRPS), Richland, WA (United States); Cooke, G. A. [Washington River Protection Solutions LLC (WRPS), Richland, WA (United States)

2018-02-27

Seven grab samples and one field blank were taken from Tank 241-AW-104 (AW-104) on June 2, 2017, and received at 222-S Laboratory on June 5, 2017. A visible layer with brown solids was observed floating on the top of two surface tank waste samples (4AW-17-02 and 4AW 17 02DUP). The floating layer from both samples was collected, composited, and submitted for chemical analyses and solid phase characterization in order to understand the composition of the floating layer. Tributyl phosphate and tridecane were higher in the floating layer than in the aqueous phase. Density in the floating layer was slightly lower than the mean density of all grab samples. Sodium nitrate and sodium carbonate were major components with a trace of gibbsite and very small size agglomerates were present in the solids of the floating layer. The supernate consisted of organics, soluble salt, and particulates.

Offshore system for integration of the wind energy; Sistema offshore para integracao de energia eolica

Energy Technology Data Exchange (ETDEWEB)

Decker, Jan de [3E, Brussels (Belgium); Tambke, Jens [Universidade de Oldemburg (Germany). ForWind; Voelker, J. [Dena - Agencia Alema de Energia (Germany); Michalowska-Knap, Katarzyna [Instituto de Energia Renovavel (Poland)

2010-09-15

The Offshore Grid project aims to analyze the conditions required for the development of an offshore transmission network to integrate renewable energy (wind) to the national electrical systems, securely and efficiently. Regulatory aspects, technical, economic and political are considered, that will help the various players in the industry to have a common view on the offshore power grids in Europe.

Floating venous thrombi: diagnosis with spiral-CT-venography

International Nuclear Information System (INIS)

Gartenschlaeger, M.; Schmidt, J.A.

1996-01-01

Local application of contrast agent into an ipsilateral dorsal foot vein and spiral CT were used to examine 16 consecutive cases with deep venous thrombosis proven at conventional venography; in addition, colour Doppler flow imaging was performed. At conventional venography, 8/16 thrombi appeared to be floating and the remaining 8/16 were adherent to the vessel wall. Spiral-CT showed 15/16 thrombi to be adherent to the vessel wall; the floating thrombus correlated with findings in conventional venography. At colour Doppler flow imaging 3/16 thrombi were considered floating, one of them was discordant to conventional venography. The comparison of conventional venography to spiral-CT demonstrates complete agreement for adherence to vessel wall seen in conventional venography (p=1,0) and significant discordance in cases with free-floating appearance in conventional venography. Adherence of thrombi to the wall of the vessel at conventional venography is in agreement with computed tomography. Conventional venography probably overestimates the prevalence of free floating thrombi. (orig./MG) [de

Design, numerical modelling and analysis of a spar floater supporting the DTU 10MW wind turbine

OpenAIRE

Xue, Wenfei

2016-01-01

Nowadays, wind energy is one of the most promising, sustainable and clean energy solutions for the future. The wind industry in Europe experiences a very fast development these years, moving from onshore to offshore in shallow water and then in deep water. A floating wind turbine is an offshore wind turbine mounted on a floating structure that allows the turbine to generate electricity in water depths where bottom-fixed towers are not accessible. However, the offshore wind energy still has...

A New Coordinated Voltage Control Scheme for Offshore AC Grid of HVDC Connected Offshore Wind Power Plants

DEFF Research Database (Denmark)

Sakamuri, Jayachandra N.; Cutululis, Nicolaos Antonio; Rather, Zakir Hussain

2015-01-01

This paper proposes a coordinated voltage control scheme (CVCS) which enhances the voltage ride through (VRT) capability of an offshore AC grid comprised of a cluster of offshore wind power plants (WPP) connected through AC cables to the offshore voltage source converter based high voltage DC (VSC......-HVDC) converter station. Due to limited short circuit power contribution from power electronic interfaced variable speed wind generators and with the onshore main grid decoupled by the HVDC link, the offshore AC grid becomes more vulnerable to dynamic voltage events. Therefore, a short circuit fault...... in the offshore AC Grid is likely to have significant implications on the voltage of the offshore AC grid, hence on the power flow to the onshore mainland grid. The proposed CVCS integrates individual local reactive power control of wind turbines and of the HVDC converter with the secondary voltage controller...

Huge cystic craniopharyngioma with unusual extensions

Energy Technology Data Exchange (ETDEWEB)

Kitano, I.; Yoneda, K.; Yamakawa, Y.; Fukui, M.; Kinoshita, K.

1981-09-01

The findings on computed tomography (CT) of a huge cystic craniopharyngioma in a 3-year-old girl are described. The cyst occupied both anterior cranial fossae and a part of it extended to the region of the third ventricle which was displaced posteriorly. The tumor showed no contrast enhancement after the intravenous administration of contrast medium.

Herbal carrier-based floating microparticles of diltiazem ...

African Journals Online (AJOL)

Purpose: To formulate and characterize a gastroretentive floating drug delivery system for diltiazem hydrochloride using psyllium husk and sodium alginate as natural herbal carriers to improve the therapeutic effect of the drug in cardiac patients. Methods: Floating microparticles containing diltiazem hydrochloride were ...

Offshore Wind Market and Economic Analysis

Energy Technology Data Exchange (ETDEWEB)

Hamilton, Bruce Duncan [Navigant Consulting, Inc., Chicago, IL (United States)

2014-08-27

This report is the third annual assessment of the U.S. offshore wind market. It includes the following major sections: Section 1: key data on developments in the offshore wind technology sector and the global development of offshore wind projects, with a particular focus on progress in the United States; Section 2: analysis of policy developments at the federal and state levels that have been effective in advancing offshore wind deployment in the United States; Section 3: analysis of actual and projected economic impact, including regional development and job creation; Section 4: analysis of developments in relevant sectors of the economy with the potential to affect offshore wind deployment in the United States

Import, Offshoring and Wages

DEFF Research Database (Denmark)

Fosse, Henrik Barslund; Maitra, Madhura

Offshoring firms are found to pay higher average wages than purely domestic firms. We provide a unifying empirical approach by capturing the different channels through which offshoring may explain this wage difference: (i) due to change in the composition of workers (skill composition effect) (ii......) because all existing workers get higher pay (rent sharing effect). Using Danish worker-firm data we explain how much each channel contributes to higher wages. To estimate the causal effect of offshoring on wages we use China’s accession to the WTO in December 2001 - and the soon after boom in Chinese...

Cholecystosonographic findings of clonorchiasis: Floating echogenic foci

Energy Technology Data Exchange (ETDEWEB)

Kim, Ho Kyun [Choong Joo X-ray Clinic, Choongjoo (Korea, Republic of)

1989-06-15

Author analysed cholecystosonographic findings in 22 patients with clonorchiasis, suspected prospectively by ultrasound and proved subsequently by demonstration of eggs in the stools. Fifteen gallbladders had nonshadowing, fusiform, discrete echogenic foci measuring 3{approx}6 mm in the lumen. Among these, the echogenic foci floated spontaneously in three cases, while in twelve cases they floated by position change or a light blow by the transducer. In the rest of the seven gallbladders, the echogenic foci were at the dependent portion. In the in vitro study with a worm suspension in saline in a surgical glove, the same echogenic foci as those seen in the gallbladders were demonstrated. The echogenic foci were precipitated in the dependent portion but float with a light blow on the glove. Author conclude that the floating echogenic foci in the lumen of the gallbladder are due to adult worms of clonorchis sinensis.

Cholecystosonographic findings of clonorchiasis: Floating echogenic foci

International Nuclear Information System (INIS)

Kim, Ho Kyun

1989-01-01

Author analysed cholecystosonographic findings in 22 patients with clonorchiasis, suspected prospectively by ultrasound and proved subsequently by demonstration of eggs in the stools. Fifteen gallbladders had nonshadowing, fusiform, discrete echogenic foci measuring 3∼6 mm in the lumen. Among these, the echogenic foci floated spontaneously in three cases, while in twelve cases they floated by position change or a light blow by the transducer. In the rest of the seven gallbladders, the echogenic foci were at the dependent portion. In the in vitro study with a worm suspension in saline in a surgical glove, the same echogenic foci as those seen in the gallbladders were demonstrated. The echogenic foci were precipitated in the dependent portion but float with a light blow on the glove. Author conclude that the floating echogenic foci in the lumen of the gallbladder are due to adult worms of clonorchis sinensis

The economics of offshore wind

International Nuclear Information System (INIS)

Green, Richard; Vasilakos, Nicholas

2011-01-01

This paper presents an overview of the main issues associated with the economics of offshore wind. Investment in offshore wind systems has been growing rapidly throughout Europe, and the technology will be essential in meeting EU targets for renewable energy in 2020. Offshore wind suffers from high installation and connection costs, however, making government support essential. We review various support policies used in Europe, concluding that tender-based feed-in tariff schemes, as used in Denmark, may be best for providing adequate support while minimising developers' rents. It may prove economic to build an international offshore grid connecting wind farms belonging to different countries that are sited close to each other. (author)

The economics of offshore wind

Energy Technology Data Exchange (ETDEWEB)

Green, Richard; Vasilakos, Nicholas [Department of Economics, University of Birmingham, Birmingham B15 2TT (United Kingdom)

2011-02-15

This paper presents an overview of the main issues associated with the economics of offshore wind. Investment in offshore wind systems has been growing rapidly throughout Europe, and the technology will be essential in meeting EU targets for renewable energy in 2020. Offshore wind suffers from high installation and connection costs, however, making government support essential. We review various support policies used in Europe, concluding that tender-based feed-in tariff schemes, as used in Denmark, may be best for providing adequate support while minimising developers' rents. It may prove economic to build an international offshore grid connecting wind farms belonging to different countries that are sited close to each other. (author)

NREL Offshore Balance-of-System Model

Energy Technology Data Exchange (ETDEWEB)

Maness, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maples, Benjamin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-01-01

The U.S. Department of Energy (DOE) has investigated the potential for 20% of nationwide electricity demand to be generated from wind by 2030 and, more recently, 35% by 2050. Achieving this level of wind power generation may require the development and deployment of offshore wind technologies. DOE (2008) has indicated that reaching these 2030 and 2050 scenarios could result in approximately 10% and 20%, respectively, of wind energy generation to come from offshore resources. By the end of 2013, 6.5 gigawatts of offshore wind were installed globally. The first U.S. project, the Block Island Wind Farm off the coast of Rhode Island, has recently begun operations. One of the major reasons that offshore wind development in the United States is lagging behind global trends is the high capital expenditures required. An understanding of the costs and associated drivers of building a commercial-scale offshore wind plant in the United States will inform future research and help U.S. investors feel more confident in offshore wind development. In an effort to explain these costs, the National Renewable Energy Laboratory has developed the Offshore Balance-of-System model.

Offshore wind energy. An overview on the activities in Germany; Offshore-Windenergie. Ein Ueberblick ueber die Aktivitaeten in Deutschland

Energy Technology Data Exchange (ETDEWEB)

Worm, Anja [media consulta Deutschland GmbH, Berlin (Germany)

2013-02-15

The brochure under consideration provides an overview of the activities of offshore wind energy in Germany. The first offshore wind farms are built and generate more electricity than expected. The offshore wind farms serve as a field of learning for new technologies. The power of offshore wind farms opened new prospects for the economy. The northern Federal States of Germany as well as the traditional locations for mechanical engineering and steel production benefit from offshore wind energy.

Danish offshore wind - Key environmental issues

International Nuclear Information System (INIS)

2006-11-01

Danish experience from the past 15 years shows that offshore wind farms, if placed right, can be engineered and operated without significant damage to the marine environment and vulnerable species. The comprehensive environmental monitoring programmes of Horns Rev Offshore Wind Farm and Nysted Offshore Wind Farm confirm that, under the rieght conditions, even big wind farms pose low risk to birds, mammals and fish, even though there will be changes in the living conditions of some species by an increase in habitat heterogeneity. The monitoring also shows that appropriate siting of offshore wind farms is an essential precondition for ensuring limited impact on nature and the environment, and that careful spatial planning is necessary to avoid damaging cumulative impacts. Due consideration to limiting the impacts on nature together with positive attitudes towards offshore wind farms in local communities and challenging energy policy objectives at national and international levels mean that prospects look bright for future offshore expansion. (au)

Offshore Outsourcing

DEFF Research Database (Denmark)

Petersen, Bent; Benito, Gabriel R. G.; Dovgan, Olesya

While the extant literature on offshore outsourcing deals with this operation mode in isolation, and typically with a focus on cost effects, we address the broader question of how companies choose and use outsourcing as part of foreign operation mode development and as a contributor to internatio...... that outsourcing can be used proactively to promote expanded international operations.......While the extant literature on offshore outsourcing deals with this operation mode in isolation, and typically with a focus on cost effects, we address the broader question of how companies choose and use outsourcing as part of foreign operation mode development and as a contributor...

Potential of water surface-floating microalgae for biodiesel production: Floating-biomass and lipid productivities.

Science.gov (United States)

Muto, Masaki; Nojima, Daisuke; Yue, Liang; Kanehara, Hideyuki; Naruse, Hideaki; Ujiro, Asuka; Yoshino, Tomoko; Matsunaga, Tadashi; Tanaka, Tsuyoshi

2017-03-01

Microalgae have been accepted as a promising feedstock for biodiesel production owing to their capability of converting solar energy into lipids through photosynthesis. However, the high capital and operating costs, and high energy consumption, are hampering commercialization of microalgal biodiesel. In this study, the surface-floating microalga, strain AVFF007 (tentatively identified as Botryosphaerella sudetica), which naturally forms a biofilm on surfaces, was characterized for use in biodiesel production. The biofilm could be conveniently harvested from the surface of the water by adsorbing onto a polyethylene film. The lipid productivity of strain AVFF007 was 46.3 mg/L/day, allowing direct comparison to lipid productivities of other microalgal species. The moisture content of the surface-floating biomass was 86.0 ± 1.2%, which was much lower than that of the biomass harvested using centrifugation. These results reveal the potential of this surface-floating microalgal species as a biodiesel producer, employing a novel biomass harvesting and dewatering strategy. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Floating seal system for rotary devices

Science.gov (United States)

Banasiuk, H.A.

1983-08-23

This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

An Asynchronous IEEE Floating-Point Arithmetic Unit

Directory of Open Access Journals (Sweden)

Joel R. Noche

2007-12-01

Full Text Available An asynchronous floating-point arithmetic unit is designed and tested at the transistor level usingCadence software. It uses CMOS (complementary metal oxide semiconductor and DCVS (differentialcascode voltage switch logic in a 0.35 µm process using a 3.3 V supply voltage, with dual-rail data andsingle-rail control signals using four-phase handshaking.Using 17,085 transistors, the unit handles single-precision (32-bit addition/subtraction, multiplication,division, and remainder using the IEEE 754-1985 Standard for Binary Floating-Point Arithmetic, withrounding and other operations to be handled by separate hardware or software. Division and remainderare done using a restoring subtractive algorithm; multiplication uses an additive algorithm. Exceptionsare noted by flags (and not trap handlers and the output is in single-precision.Previous work on asynchronous floating-point arithmetic units have mostly focused on single operationssuch as division. This is the first work to the authors' knowledge that can perform floating-point addition,multiplication, division, and remainder using a common datapath.

2016 Offshore Wind Market Report

Energy Technology Data Exchange (ETDEWEB)

Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schwabe, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Spitsen, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-08-07

The 2016 Offshore Wind Technologies Market Report is intended to provide stakeholders with quantitative information about the offshore wind market, technology, and cost trends in the United States and worldwide.

CFD for wind and tidal offshore turbines

CERN Document Server

Montlaur, Adeline

2015-01-01

The book encompasses novel CFD techniques to compute offshore wind and tidal applications. Computational fluid dynamics (CFD) techniques are regarded as the main design tool to explore the new engineering challenges presented by offshore wind and tidal turbines for energy generation. The difficulty and costs of undertaking experimental tests in offshore environments have increased the interest in the field of CFD which is used to design appropriate turbines and blades, understand fluid flow physical phenomena associated with offshore environments, predict power production or characterise offshore environments, amongst other topics.

Study on the application of energy storage system in offshore wind turbine with hydraulic transmission

International Nuclear Information System (INIS)

Fan, Yajun; Mu, Anle; Ma, Tao

2016-01-01

Highlights: • Hydraulic offshore wind turbine is capable of outputting near constant power. • Open loop hydraulic transmission uses seawater as the working fluid. • Linear control strategy distributes total flow according to demand and supply. • Constant pressure hydraulic accumulator stores/releases the surplus energy. • Simulations show the dynamic performance of the hybrid system. - Abstract: A novel offshore wind turbine comprising fluid power transmission and energy storage system is proposed. In this wind turbine, the conventional mechanical transmission is replaced by an open-loop hydraulic system, in which seawater is sucked through a variable displacement pump in nacelle connected directly with the rotor and utilized to drive a Pelton turbine installed on the floating platform. Aiming to smooth and stabilize the output power, an energy storage system with the capability of flexible charging and discharging is applied. The related mathematical model is developed, which contains some sub-models that are categorized as the wind turbine rotor, hydraulic pump, transmission pipeline, proportional valve, accumulator and hydraulic turbine. A linear control strategy is adopted to distribute the flow out of the proportional valve through comparing the demand power with captured wind energy by hydraulic pump. Ultimately, two time domain simulations demonstrate the operation of the hybrid system when the hydraulic accumulator is utilized and show how this system can be used for load leveling and stabilizing the output power.

Newtonian self-gravitating system in a relativistic huge void universe model

Energy Technology Data Exchange (ETDEWEB)

Nishikawa, Ryusuke; Nakao, Ken-ichi [Department of Mathematics and Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 (Japan); Yoo, Chul-Moon, E-mail: ryusuke@sci.osaka-cu.ac.jp, E-mail: knakao@sci.osaka-cu.ac.jp, E-mail: yoo@gravity.phys.nagoya-u.ac.jp [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

2016-12-01

We consider a test of the Copernican Principle through observations of the large-scale structures, and for this purpose we study the self-gravitating system in a relativistic huge void universe model which does not invoke the Copernican Principle. If we focus on the the weakly self-gravitating and slowly evolving system whose spatial extent is much smaller than the scale of the cosmological horizon in the homogeneous and isotropic background universe model, the cosmological Newtonian approximation is available. Also in the huge void universe model, the same kind of approximation as the cosmological Newtonian approximation is available for the analysis of the perturbations contained in a region whose spatial size is much smaller than the scale of the huge void: the effects of the huge void are taken into account in a perturbative manner by using the Fermi-normal coordinates. By using this approximation, we derive the equations of motion for the weakly self-gravitating perturbations whose elements have relative velocities much smaller than the speed of light, and show the derived equations can be significantly different from those in the homogeneous and isotropic universe model, due to the anisotropic volume expansion in the huge void. We linearize the derived equations of motion and solve them. The solutions show that the behaviors of linear density perturbations are very different from those in the homogeneous and isotropic universe model.

Energy from Offshore Wind: Preprint

Energy Technology Data Exchange (ETDEWEB)

Musial, W.; Butterfield, S.; Ram, B.

2006-02-01

This paper provides an overview of the nascent offshore wind energy industry including a status of the commercial offshore industry and the technologies that will be needed for full market development.

Aerodynamics and Motion Performance of the H-Type Floating Vertical Axis Wind Turbine

Directory of Open Access Journals (Sweden)

Ying Guo

2018-02-01

Full Text Available Aerodynamics and motion performance of the floating vertical wind turbine (VAWT were studied in this paper, where the wind turbine was H-type and the floating foundation was truss spar type. Based on the double-multiple-stream-tube theory, the formulae were deduced to calculate the aerodynamic loads acting on the wind turbine considering the motions of the floating foundation. The surge-heave-pitch nonlinear coupling equations of the H-type floating VAWT were established. Aerodynamics and motion performance of a 5 MW H-type floating VAWT was studied, and the effect of the floating foundation motions on the aerodynamic loads was analyzed. It is shown that the motions of the floating foundation on the aerodynamics cannot be ignored. The motion of the H-type floating VAWT was also compared with that of the Φ-type floating VAWT: they have the same floating foundation, rated output power, mooring system and total displacement. The results show that the H-type floating VAWT has better motion performance, and the mean values of surge, heave and pitch of the H-type floating VAWT are much smaller comparing with the Φ-type floating VAWT.

Utilizing offshore potentials for wind power generation; Nutzung der Offshore-Potentiale fuer die Windenergie

Energy Technology Data Exchange (ETDEWEB)

Hannemann, H. [Neptun Industrie GmbH, Rostock (Germany)

2000-07-01

The contribution discusses the importance of the offshore market and recommends measures to develop it. A turnkey offer is required for exports, which means that all organisations cooperating in the pilot project must prove their competence. The status of a pilot project in the Baltic Sea and the further plans for the park (20 systems, 40 MW, more than 10 km off the coast, water depth about 20 m) are reviewed. [German] Zur Erschliessung des Offshore - Marktes fuer Windenergieanlagen ist es erforderlich, die Technologie ''vor der eigenen Haustuer'' demonstrieren zu koennen. Nach einer Betrachtung der europaeischen Offshore - Windenergie - Potentiale und der davon moeglicherweise nutzbaren Anteile wird die Bedeutung des Offshore - Marktes deutlich. Besonders fuer die Hersteller ist der Offshore - Markt fuer den langfristigen Export von besonderer Bedeutung. Um den Export zu realisieren, ist ein Turnkey - Angebot erforderlich, so dass im Pilotprojekt alle an der gesamten Realisation beteiligten Organisationen ihre Kompetenz beweisen muessen und koennen. Der Stand eines Pilotprojektes in der Ostsee und die weitere Planung fuer den Park (20 Anlagen, 40 MW, >10 km Kuestenentfernung, ca. 20 m Wassertiefe) wird dargestellt. (orig.)

Recursive thoughts on the simulation of the flexible multibody dynamics of slender offshore structures

Science.gov (United States)

Schilder, J.; Ellenbroek, M.; de Boer, A.

2017-12-01

In this work, the floating frame of reference formulation is used to create a flexible multibody model of slender offshore structures such as pipelines and risers. It is shown that due to the chain-like topology of the considered structures, the equation of motion can be expressed in terms of absolute interface coordinates. In the presented form, kinematic constraint equations are satisfied explicitly and the Lagrange multipliers are eliminated from the equations. Hence, the structures can be conveniently coupled to finite element or multibody models of for example seabed and vessel. The chain-like topology enables the efficient use of recursive solution procedures for both transient dynamic analysis and equilibrium analysis. For this, the transfer matrix method is used. In order to improve the convergence of the equilibrium analysis, the analytical solution of an ideal catenary is used as an initial configuration, reducing the number of required iterations.

Wind energy in offshore grids

Energy Technology Data Exchange (ETDEWEB)

Schroeder, S.T.

2013-01-15

This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid affects the economics of an offshore wind park. It is shown that the spot market income is lower if an offshore wind farm is placed in an interconnector and subject to nodal pricing instead of having a national affiliation. Moreover, congestion in the interconnector can prevent the wind farm from correcting its wind forecast errors in a specific onshore balancing group. An analytical approach with a transmission system operator and a wind farm as stakeholders illustrates resulting incentives for strategic behaviour. Depending on the regulatory regime, they may be inclined to announce more or less generation than expected at the closure of the day-ahead spot market. This can lead to a suboptimal utilisation of the infrastructure and associated socio-economic losses. These and possibly undesired reallocative effects between the parties can be avoided if the regulatory regime is adjusted to reflect special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment framework has also been addressed with a policy study about possible combinations of support schemes and international cooperation mechanisms between countries to achieve their

IS OFFSHORING AN INTERNATIONAL PROCESS

Directory of Open Access Journals (Sweden)

Paulo Roberto Gião

2012-01-01

Full Text Available This article proposes to analyze the applicability of transaction cost economics - TCE (Coase, 1937; Williamson, 1975, 1979 through its characteristic make-or-buy expression, considering the offshoring pace and emerging economy firms. The make-or-buy decision must be flexible enough to explain offshoring characteristics and developed and emerging economy firms scenarios. As secondary objectives, and to show the trail to the main purpose, two research questions were identified and discussed during the paper: Is offshoring process an international movement only from developed countries to emerging economies? Is the main reason of offshoring the looking for low-cost work / activities? To achieve the proposed objectives, the structure of this paper begins with a reasonable or acceptable definition of offshoring. Some reasons (or “the reason” for the process are also another important starting point. The majority of articles referee the idea that low-cost is the main reason for offshoring, and if it is correct, transaction cost economics seems to be a good basis for our analysis purpose and integrative intention. Also some literature connections between offshoring and TCE are presented and, naturally TCE is presented in highlights for understanding these connections. Ending this section, some different arguments based on newer researches are presented by some authors presenting another perspective as the main reason. After this theoretical approach, a scenario analysis and some discussions are presented based on all possible interactions among firm from developed (DC and emerging economies (EE and examples of international corporations are presented to clarify and improve the understanding of our research questions and to build new contributions to international business theory.

An air quality emission inventory of offshore operations for the exploration and production of petroleum by the Mexican oil industry

Science.gov (United States)

Villasenor, R.; Magdaleno, M.; Quintanar, A.; Gallardo, J. C.; López, M. T.; Jurado, R.; Miranda, A.; Aguilar, M.; Melgarejo, L. A.; Palmerín, E.; Vallejo, C. J.; Barchet, W. R.

An air quality screening study was performed to assess the impacts of emissions from the offshore operations of the oil and gas exploration and production by Mexican industry in the Campeche Sound, which includes the states of Tabasco and Campeche in southeast Mexico. The major goal of this study was the compilation of an emission inventory (EI) for elevated, boom and ground level flares, processes, internal combustion engines and fugitive emissions. This inventory is so far the most comprehensive emission register that has ever been developed for the Mexican petroleum industry in this area. The EI considered 174 offshore platforms, the compression station at Atasta, and the Maritime Ports at Dos Bocas and Cayo Arcas. The offshore facilities identified as potential emitters in the area were the following: (1) trans-shipment stations, (2) a maritime floating port terminal, (3) drilling platforms, (4) crude oil recovering platforms, (5) crude oil production platforms, (6) linking platforms, (7) water injection platforms, (8) pumping platforms, (9) shelter platforms, (10) telecommunication platforms, (11) crude oil measurement platforms, and (12) flaring platforms. Crude oil storage tanks, helicopters and marine ship tankers were also considered to have an EI accurate enough for air quality regulations and mesoscale modeling of atmospheric pollutants. Historical ambient data measure at two onshore petroleum facilities were analyzed to measure air quality impacts on nearby inhabited coastal areas, and a source-receptor relationship for flares at the Ixtoc marine complex was performed to investigate health-based standards for offshore workers. A preliminary air quality model simulation was performed to observe the transport and dispersion patterns of SO 2, which is the main pollutant emitted from the offshore platforms. The meteorological wind and temperature fields were generated with CALMET, a diagnostic meteorological model that used surface observations and upper

The Economic Geography of Offshoring

DEFF Research Database (Denmark)

Ørberg Jensen, Peter D.; Pedersen, Torben

2011-01-01

when distinguishing between standardized and advanced activities. Asia attracts as many advanced activities as Western Europe while North America attracts more advanced activities even in manufacturing. Central and Eastern Europe attract offshoring in manufacturing and IT, but the activities...... that are offshored to these regions are typically not advanced. One important theoretical implication of this study is that a more detailed understanding of the nature of offshored activities is needed, since such attributes appear to be an important determinant of location choice....

Earth Observations in Support of Offshore Wind Energy Management in the Euro-Atlantic Region

Science.gov (United States)

Liberato, M. L. R.

2017-12-01

Climate change is one of the most important challenges in the 21st century and the energy sector is a major contributor to GHG emissions. Therefore greater attention has been given to the evaluation of offshore wind energy potentials along coastal areas, as it is expected offshore wind energy to be more efficient and cost-effective in the near future. Europe is developing offshore sites for over two decades and has been growing at gigawatt levels in annual capacity. Portugal is among these countries, with the development of a 25MW WindFloat Atlantic wind farm project. The international scientific community has developed robust ability on the research of the climate system components and their interactions. Climate scientists have gained expertise in the observation and analysis of the climate system as well as on the improvement of model and predictive capabilities. Developments on climate science allow advancing our understanding and prediction of the variability and change of Earth's climate on all space and time scales, while improving skilful climate assessments and tools for dealing with future challenges of a warming planet. However the availability of greater datasets amplifies the complexity on manipulation, representation and consequent analysis and interpretation of such datasets. Today the challenge is to translate scientific understanding of the climate system into climate information for society and decision makers. Here we discuss the development of an integration tool for multidisciplinary research, which allows access, management, tailored pre-processing and visualization of datasets, crucial to foster research as a service to society. One application is the assessment and monitoring of renewable energy variability, such as wind or solar energy, at several time and space scales. We demonstrate the ability of the e-science platform for planning, monitoring and management of renewable energy, particularly offshore wind energy in the Euro

Offshoring and Changes in Firms’ Domestic Employment

DEFF Research Database (Denmark)

Timmermans, Bram; Østergaard, Christian Richter

difference on a set of employment characteristics, i.e. employment growth, growth in high skilled employees, and growth in employees with a background in science and engineering, by using a partial propensity score matching approach. The findings of the analyses show that there are clear differences between......In this paper, we investigate, by merging the Danish linked employer-employee database with a Danish offshoring survey, the difference in employment between offshoring and non-offshoring firms that are active in manufacturing industries and business services in Denmark. We measure the mean...... Danish offshoring and non-offshoring firms in how the employee composition changes over time. The change in employment composition differ considerably between manufacturing industries and business services and on whether firms offshore administrative and technical business functions or other types...

Floating arterial thrombus related stroke treated by intravenous thrombolysis.

Science.gov (United States)

Vanacker, P; Cordier, M; Janbieh, J; Federau, C; Michel, P

2014-01-01

The effects of intravenous thrombolysis on floating thrombi in cervical and intracranial arteries of acute ischemic stroke patients are unknown. Similarly, the best prevention methods of early recurrences remain controversial. This study aimed to describe the clinical and radiological outcome of thrombolyzed strokes with floating thrombi. We retrospectively analyzed all thrombolyzed stroke patients in our institution between 2003 and 2010 with floating thrombi on acute CT-angiography before the intravenous thrombolysis. The floating thrombus was diagnosed if an elongated thrombus of at least 5 mm length, completely surrounded by contrast on supra-aortic neck or intracerebral arteries, was present on CT-angiography. Demographics, vascular risk factors, and comorbidities were recorded and stroke etiology was determined after a standardized workup. Repeat arterial imaging was performed by CTA at 24 h or before if clinical worsening was noted and then by Doppler and MRA during the first week and at four months. Of 409 thrombolyzed stroke patients undergoing acute CT Angiography, seven (1.7%) had a floating thrombus; of these seven, six had it in the anterior circulation. Demographics, risk factors and stroke severity of these patients were comparable to the other thrombolyzed patients. After intravenous thrombolysis, the floating thrombi resolved completely at 24 h in four of the patients, whereas one had an early recurrent stroke and one developed progressive worsening. One patient developed early occlusion of the carotid artery with floating thrombus and subsequently a TIA. The two patients with a stable floating thrombus had no clinical recurrences. In the literature, only one of four reported cases were found to have a thrombolysis-related early recurrence. Long-term outcome seemed similar in thrombolyzed patients with floating thrombus, despite a possible increase of very early recurrence. It remains to be established whether acute mechanical thrombectomy could be

NEW OFFSHORE LOCATIONS IN THE EUROPEAN UNION

Directory of Open Access Journals (Sweden)

RADULESCU IRINA GABRIELA

2014-05-01

Full Text Available The offshore activity provides benefits for the host market and has positive effects on services, and on producers that use intermediate services. FDI in services has an important impact on the offshore activity, especially through transfer of technology. Many transnational companies have recognized the advantages of offshoring and the fact that it becomes a key globalization force. Recently, the Central European countries have become popular destinations among offshoring

Can flexibility help you float?

Science.gov (United States)

Burton, L. J.; Bush, J. W. M.

2012-10-01

We consider the role of flexibility in the weight-bearing characteristics of bodies floating at an interface. Specifically, we develop a theoretical model for a two-dimensional thin floating plate that yields the maximum stable plate load and optimal stiffness for weight support. Plates small relative to the capillary length are primarily supported by surface tension, and their weight-bearing potential does not benefit from flexibility. Above a critical size comparable to the capillary length, flexibility assists interfacial flotation. For plates on the order of and larger than the capillary length, deflection from an initially flat shape increases the force resulting from hydrostatic pressure, allowing the plate to support a greater load. In this large plate limit, the shape that bears the most weight is a semicircle, which displaces the most fluid above the plate for a fixed plate length. Exact results for maximum weight-bearing plate shapes are compared to analytic approximations made in the limits of large and small plate sizes. The value of flexibility for floating to a number of biological organisms is discussed in light of our study.

Noise from offshore wind turbines

Energy Technology Data Exchange (ETDEWEB)

Soendergaard, B.; Plovsing, B.

2005-07-01

Noise assessment of wind turbines through calculations is based on sound power levels measured according to e.g. IEC 61400-11. With larger wind turbines and distances some of the calculation models give erroneous results. Noise propagation over water is different from propagation over land. For that reason it is important be able to make valid noise assessments for offshore wind farms. A suggestion for an offshore measurement method is described and a survey of models for noise propagation offshore has been made. (au)

Fully Coupled Three-Dimensional Dynamic Response of a Tension-Leg Platform Floating Wind Turbine in Waves and Wind

DEFF Research Database (Denmark)

Kumari Ramachandran, Gireesh Kumar Vasanta; Bredmose, Henrik; Sørensen, Jens Nørkær

2014-01-01

, which is a consequence of the wave-induced rotor dynamics. Loads and coupled responses are predicted for a set of load cases with different wave headings. Further, an advanced aero-elastic code, Flex5, is extended for the TLP wind turbine configuration and the response comparison with the simpler model......A dynamic model for a tension-leg platform (TLP) floating offshore wind turbine is proposed. The model includes three-dimensional wind and wave loads and the associated structural response. The total system is formulated using 17 degrees of freedom (DOF), 6 for the platform motions and 11...... for the wind turbine. Three-dimensional hydrodynamic loads have been formulated using a frequency-and direction-dependent spectrum. While wave loads are computed from the wave kinematics using Morison's equation, the aerodynamic loads are modeled by means of unsteady blade-element-momentum (BEM) theory...

14 CFR 25.533 - Hull and main float bottom pressures.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and main float bottom pressures. 25... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.533 Hull and main float bottom pressures. (a) General. The hull and main float structure, including frames and bulkheads...

Simulation of rectifier voltage malfunction on OWECS, four-level converter, HVDC light link: Smart grid context tool

International Nuclear Information System (INIS)

Seixas, M.; Melício, R.; Mendes, V.M.F.

2015-01-01

Highlights: • Floating offshore wind turbine in deep water. • DC link and voltage malfunction. • Converter topology considered is four-level. • Controllers are based on fractional-order. • Smart grid context. - Abstract: This paper presents a model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase. The offshore wind system model comprises a variable-speed wind turbine supported on a floating platform, equipped with a permanent magnet synchronous generator using full-power four-level neutral point clamped converter. The link from the offshore floating platform to the onshore electrical grid is done through a light high voltage direct current submarine cable. The drive train is modeled by a three-mass model. Considerations about the smart grid context are offered for the use of the model in such a context. The rectifier voltage malfunction domino effect is presented as a case study to show capabilities of the model

Some characteristics of offshore operations

Directory of Open Access Journals (Sweden)

Popov Đorđe

2011-01-01

Full Text Available Offshore operations are not on the margins of the world economy. They are an integral part of modern business practice. They have become one of the most important instruments in the contemporary globalized financial system. Offshore operations and tax havens are not only conduits for tax avoidance and evasion but belong more broadly to the world of finance, for the business of managing the monetary resources of an organization, country or individuals. Offshore business operating in tax havens is at the heart of a particular type of globalization that is characterized by a growing gap between the very rich and everyone else. Tax havens are financial conduits that, in exchange for a fee, use their one principal asset- their sovereignty to serve a nonresident constituency of accountants and lawyers, bankers and financiers, who bring a demand for offshore operations.

Learning Paths to Offshore Outsourcing

DEFF Research Database (Denmark)

Maskell, Peter; Pedersen, Torben; Petersen, Bent

A corporation’s offshore outsourcing may be seen as the result of a discrete, strategic decision taken in response to an increasing pressure from worldwide competition. However, empirical evidence of a representative cross-sector sample of international Danish firms indicates that offshore sourcing...... in low-cost countries is best described as a learning-by-doing process in which the offshore outsourcing of a corporation goes through a sequence of stages towards sourcing for innovation. Initially, a corporation’s outsourcing is driven by a desire for cost minimization. Over a period of time...... the outsourcing experience lessens the cognitive limitations of decision-makers as to the advantages that can be achieved through outsourcing in low-cost countries: the insourcer/vendor may not only offer cost advantages, but also quality improvement and innovation. The quality improvements that offshore...

14 CFR 23.529 - Hull and main float landing conditions.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and main float landing conditions. 23... Water Loads § 23.529 Hull and main float landing conditions. (a) Symmetrical step, bow, and stern... directed perpendicularly to the keel line. (b) Unsymmetrical landing for hull and single float seaplanes...

Development and Evaluation of Floating Microspheres of Curcumin ...

African Journals Online (AJOL)

Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence time and increased drug bioavailability. Methods: Floating microsphere were prepared by emulsion solvent diffusion method, using hydroxylpropyl methylcellulose (HPMC), ethyl cellulose (EC), Eudragit S 100 polymer in ...

Huge uterine-cervical diverticulum mimicking as a cyst

Directory of Open Access Journals (Sweden)

S Chufal

2012-01-01

Full Text Available Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

Vertical pump with free floating check valve

International Nuclear Information System (INIS)

Lindsay, M.

1980-01-01

A vertical pump is described which has a bottom discharge with a free floating check valve disposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions

Development of floating strip micromegas detectors

Energy Technology Data Exchange (ETDEWEB)

Bortfeldt, Jonathan

2014-04-28

Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10{sup 34} cm{sup -2}s{sup -1} around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm{sup 2} floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm{sup 2} floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm{sup 2} floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the

Development of floating strip micromegas detectors

International Nuclear Information System (INIS)

Bortfeldt, Jonathan

2014-01-01

Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10 34 cm -2 s -1 around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm 2 floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm 2 floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm 2 floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the track inclination in a single

Offshore Wind Turbine Foundation Design

OpenAIRE

Passon, Patrik; Branner, Kim; Larsen, Søren Ejling; Hvenekær Rasmussen, Jørgen

2015-01-01

Offshore vindenergi er i høj grad modnet i det seneste årti med en årligt installeret kapacitet på mere end1 GW. En vigtig faktor for den videre udvikling af offshore vindenergi i stor målestok, er en reduktion af de samlede udgifter til produceret energi. I betragtning af for eksempel faldet i olieprisen siden sommeren 2014 og dens fortsatte fald ind i 2015, er det endnu vigtigere at sænke omkostningerne til etablering af vedvarende energikilder såsom offshore vindenergi, for at nå frem til ...

Floating barrier

Energy Technology Data Exchange (ETDEWEB)

1968-05-06

This floating barrier consists of relatively long elements which can be connected to form a practically continuous assembly. Each element consists of an inflatable tube with an apron of certain height, made of impregnated fabric which is resistant to ocean water and also to hydrocarbons. Means for connecting one element to the following one, and means for attaching ballast to the apron are also provided.

Micromechanisms with floating pivot

Science.gov (United States)

Garcia, Ernest J.

2001-03-06

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

Hanstholm phase 2B. Offshore wave energy test 1994 - 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The wave power converter consists of a float 2.5 meter in diameter, connected by a rope to a seabed-mounted piston pump, installed on 25 meter deep water 2,5 km offshore Hanstholm, Denmark. The converter is designed to absorb an average maximum power of 1 kW. Measured data in real sea conditions are compared to results based on computer simulations and previous tank testing. Losses caused by rope elasticity and hysteresis, friction in the pump and back flow through the valves are assessed. The economic perspectives of a large wave power plant are presented, based on a revised prototype incorporating the results and experience gained during the test period. The wave energy conversion test `Hanstholm phase 2B` has showed, that it it technically possible to exploit the offshore wave energy resource. This source of energy could become attractive for commercial enterprise. The wave power converter demonstrated a reliable performance over a period of nine months. It produced energy under all wave conditions and survived storm waves of 9,6 m. A 300 MW wave power plant in the Danish part of the North sea is estimated to produce electricity at a cost between 2,1 - 2,4 DKK/kWh. The electrical transmission to shore contribute to approximately 20% of the cost. New data predict a potential of 23 kW per meter wave front. The energy plan Energy 21 proposed by the Danish Department of Energy, includes a scenario incorporating wave energy in the energy system year 2030. A strategy for the development of wave energy, has been proposed as part of the project OWEC-1 supported by the European Joule R and D programme. A proposal for future Danish initiatives to develop second generation point absorber systems is outlined. (ARW) 29 refs.

Development of Offshore Wind Power Industry

Institute of Scientific and Technical Information of China (English)

Liu Xiao

2011-01-01

The offshore wind power development target as initially proposed in "The 12=Five-Year" on energy recourses development and renewable energy recourses currently under development is to reach 5m KW by 2015 and 30m KW by 2020. With the unfolding of offshore wind turbine planning from different areas, the curtain of offshore wind power development for our country's "The 12=Five-Year" has been opened.

New insights on poly(vinyl acetate)-based coated floating tablets: characterisation of hydration and CO2 generation by benchtop MRI and its relation to drug release and floating strength.

Science.gov (United States)

Strübing, Sandra; Abboud, Tâmara; Contri, Renata Vidor; Metz, Hendrik; Mäder, Karsten

2008-06-01

The purpose of this study was to investigate the mechanism of floating and drug release behaviour of poly(vinyl acetate)-based floating tablets with membrane controlled drug delivery. Propranolol HCl containing tablets with Kollidon SR as an excipient for direct compression and different Kollicoat SR 30 D/Kollicoat IR coats varying from 10 to 20mg polymer/cm2 were investigated regarding drug release in 0.1N HCl. Furthermore, the onset of floating, the floating duration and the floating strength of the device were determined. In addition, benchtop MRI studies of selected samples were performed. Coated tablets with 10mg polymer/cm2 SR/IR, 8.5:1.5 coat exhibited the shortest lag times prior to drug release and floating onset, the fastest increase in and highest maximum values of floating strength. The drug release was delayed efficiently within a time interval of 24 h by showing linear drug release characteristics. Poly(vinyl acetate) proved to be an appropriate excipient to ensure safe and reliable drug release. Floating strength measurements offered the possibility to quantify the floating ability of the developed systems and thus to compare different formulations more efficiently. Benchtop MRI studies allowed a deeper insight into drug release and floating mechanisms noninvasively and continuously.

Managing Risk Areas in Software Development Offshoring

DEFF Research Database (Denmark)

Persson, John Stouby; Schlichter, Bjarne Rerup

2015-01-01

Software companies are increasingly offshoring development to countries with high expertise at lower cost. Offshoring involves particular risk areas that if ignored increase the likelihood of failure. However, the offshoring client’s maturity level may influence the management of these risk areas...

The effects of meshed offshore grids on offshore wind investment – a real options analysis

DEFF Research Database (Denmark)

Schröder, Sascha Thorsten; Kitzing, Lena

2012-01-01

Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...... based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind...

The effects of meshed offshore grids on offshore wind investment – a real options analysis

DEFF Research Database (Denmark)

Schröder, Sascha Thorsten; Kitzing, Lena

2012-01-01

based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind......Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...

Dynamic response signatures of a scaled model platform for floating wind turbines in an ocean wave basin.

Science.gov (United States)

Jaksic, V; O'Shea, R; Cahill, P; Murphy, J; Mandic, D P; Pakrashi, V

2015-02-28

Understanding of dynamic behaviour of offshore wind floating substructures is extremely important in relation to design, operation, maintenance and management of floating wind farms. This paper presents assessment of nonlinear signatures of dynamic responses of a scaled tension-leg platform (TLP) in a wave tank exposed to different regular wave conditions and sea states characterized by the Bretschneider, the Pierson-Moskowitz and the JONSWAP spectra. Dynamic responses of the TLP were monitored at different locations using load cells, a camera-based motion recognition system and a laser Doppler vibrometer. The analysis of variability of the TLP responses and statistical quantification of their linearity or nonlinearity, as non-destructive means of structural monitoring from the output-only condition, remains a challenging problem. In this study, the delay vector variance (DVV) method is used to statistically study the degree of nonlinearity of measured response signals from a TLP. DVV is observed to create a marker estimating the degree to which a change in signal nonlinearity reflects real-time behaviour of the structure and also to establish the sensitivity of the instruments employed to these changes. The findings can be helpful in establishing monitoring strategies and control strategies for undesirable levels or types of dynamic response and can help to better estimate changes in system characteristics over the life cycle of the structure. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Pengaruh Frekuensi Melihat Iklan Floating terhadap Tingkat Kesadaran Merek

Directory of Open Access Journals (Sweden)

Forddhanto Bimantoro

2013-11-01

Full Text Available Abstract: Floating ad  is online advertisement aiming to stimulate brand awareness by increasing familiarity through reexposing advertisement. This research examines the influence of ARCO Depok members’ exposure of floating ad at www.detik.com to their brand awareness about Samsung LED TV. The frequency of consuming the advertisement is differentiated into three categories, namely three times, five times and never. The result shows that the respondents’ exposure of floating ad could influence the level of brand awareness as much as 40.7%. However, this tendency was not represented in the category of five times. The result also shows that the only control variable which was able to significantly influence the level of brand awareness was the variable of respondents’ visitation to the site of detik.com. Abstrak: Iklan floating merupakan iklan di media internet yang bertujuan mencapai kesadaran merek dengan cara meningkatkan familiarity melalui frekuensi pengulangan iklan. Frekuensi melihat iklan floating dibedakan  dengan memilah kelompok responden yang dikenai frekuensi melihat iklan 3 kali, 5 kali dan tidak melihat iklan. Penelitian ini menguji pengaruh frekuensi melihat iklan floating di www.detik.com terhadap tingkat kesadaran merek Samsung LED TV pada warga ARCO Depok, Jawa Barat. Hasil penelitian menunjukkan bahwa frekuensi melihat iklan floating dapat mempengaruhi tingkat kesadaran merek sebesar 40,7%; namun tidak terbukti pada kelompok yang melihat iklan sebanyak lima kali. Variabel kontrol yang mampu mempengaruhi tingkat kesadaran merek secara signifikan hanya variabel kunjungan responden ke detik.com.Â

Wave Run-Up on Offshore Windturbine Foundations

DEFF Research Database (Denmark)

Frigaard, Peter; De Vos, Leen

2005-01-01

In the last decade, several offshore wind-farms are built and offshore wind energy promises to be a suitable alternative to provide green energy. However, there still are some engineering challenges in placing the wind turbine foundations offshore. For example, unexpected damage to boat landing...

China: an emerging offshore wind development hotspot. With a new assessment of China's offshore wind potential

Energy Technology Data Exchange (ETDEWEB)

Reinvang, Rasmus; Enslow, Rachel; Beaumont, Hubert

2010-08-15

This study provides new and more detailed estimates of the offshore wind energy resources in China, with particular focus on Southern China. The study points out that the offshore wind industry is ramping up in China with at least 11.9GW in the development pipeline per April 2010. The study estimates the offshore wind potential of China (excluding Taiwan) to 11,580TWh/year. The study proves estimates and wind energy resource maps per province. Fujian, Zhejiang and Hainan stand out with the highest offshore wind speeds in China while Guangdong also shows significant potential, with annual wind speed averages of 6.5-10.2m/s and an energy density range of 12-36GWh/km2. Even though current offshore wind development is mainly taking place in Fujian and Jiangsu, this study shows that the potential is likely even greater in other provinces. The study was developed by the Chinese Wind Energy Association (CWEA) and Sun Yat-sen University, and commissioned by WWF as part of a project funded by the Norwegian Agency of development Coopeartion (Norad). Methodology and constraints: The wind resource analysis improves upon previous studies in estimating the wind energy generation potential for offshore wind power in China, with available meteorological data adjusted for influence of typhoons. The study models how much energy offshore wind can produce along China's coast up to 100km from the shore by calculating the energy output of theoretical wind farms by applying the power curve of a 3MW turbine at a 100m hub height. In addition the study further expands by giving special consideration to the deep-sea offshore potential at +50m water depths. The study focuses particularly on the coastline from Shandong down to Hainan. The final results provide good indication of the offshore wind resource in China when comparing one area to the other. The report can therefore be used as a preliminary tool to identifying most interesting provinces and locations for offshore wind

Capture of free-floating planets by planetary systems

Science.gov (United States)

Goulinski, Nadav; Ribak, Erez N.

2018-01-01

Evidence of exoplanets with orbits that are misaligned with the spin of the host star may suggest that not all bound planets were born in the protoplanetary disc of their current planetary system. Observations have shown that free-floating Jupiter-mass objects can exceed the number of stars in our Galaxy, implying that capture scenarios may not be so rare. To address this issue, we construct a three-dimensional simulation of a three-body scattering between a free-floating planet and a star accompanied by a Jupiter-mass bound planet. We distinguish between three different possible scattering outcomes, where the free-floating planet may get weakly captured after the brief interaction with the binary, remain unbound or 'kick out' the bound planet and replace it. The simulation was performed for different masses of the free-floating planets and stars, as well as different impact parameters, inclination angles and approach velocities. The outcome statistics are used to construct an analytical approximation of the cross-section for capturing a free-floating planet by fitting their dependence on the tested variables. The analytically approximated cross-section is used to predict the capture rate for these kinds of objects, and to estimate that about 1 per cent of all stars are expected to experience a temporary capture of a free-floating planet during their lifetime. Finally, we propose additional physical processes that may increase the capture statistics and whose contribution should be considered in future simulations in order to determine the fate of the temporarily captured planets.

2016 Offshore Wind Technologies Market Report

Energy Technology Data Exchange (ETDEWEB)

Musial, Walter; Beiter, Philipp; Schwabe, Paul; Tian, Tian; Stehly, Tyler; Spitsen, Paul; Robertson, Amy; Gevorgian, Vahan

2017-08-08

The 2016 Offshore Wind Technologies Market Report was developed by the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy (DOE) and is intended to provide offshore wind policymakers, regulators, developers, researchers, engineers, financiers, and supply chain participants, with quantitative information about the offshore wind market, technology, and cost trends in the United States and worldwide. In particular, this report is intended to provide detailed information on the domestic offshore wind industry to provide context to help navigate technical and market barriers and opportunities. The scope of the report covers the status of the 111 operating offshore wind projects in the global fleet through December 31, 2016, and provides the status and analysis on a broader pipeline of 593 projects at some stage of development. In addition, this report provides a wider assessment of domestic developments and events through the second quarter of 2017 to provide a more up-to-date discussion of this dynamically evolving industry.

A review on design and study of floating plant mooring systems

International Nuclear Information System (INIS)

Nakamura, Hideharu; Kashima, Ryoichi; Hagiwara, Yutaka; Matsuura, Shinichi; Shiojiri, Hiroo

1985-01-01

There exists a widespread anticipation among nuclear power engineers that a floating nuclear power plant (NPP) may have a couple of advantages over other types; such as seismic isolation, standardizations of design and manufacturing etc. However, it also seems that a number of problems still remain to be clarified to adopt the floating NPP in Japan. One of them is magnitude of external forces acting on floating structure, which depend on mooring system. The purpose of the present report is to survey various kinds of mooring systems, structural analyses and design criteria, and examples of the same scale floating structures taking into consideration of the floating NPP which displaces 300,000 Ton, and furthermore, to discuss the future problems in regard to the mooring system still to be investigated before the floating plants can be constructed. (author)

Connecting slow earthquakes to huge earthquakes

OpenAIRE

Obara, Kazushige; Kato, Aitaro

2016-01-01

Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

Experience of measuring wall thicknesses of district heating pipes in use with free-floating salamanders (pigs)

International Nuclear Information System (INIS)

Barbian, O.A.; Goedecke, H.; Krieg, W.

1992-01-01

A test system for district heating pipes (laid above ground or in the ground or in the offshore field) is introduced, a so-called 'intelligent' test 'pig' which, like in a pneumatic tube, floats through the pipe with the medium during operation and finds out any corrosion damage. The equipment works on the principle of ultrasonic wall thickness testing in immersed technique, and is equipped with a large number of test heads in order to scan the pipe surface completely in one run-through. The data processing in the pig with the aid of microprocessors and the type of data collection in mass memories is briefly described. The test results are clearly shown by coloured graphics, which makes efficient assessment and evaluation of the faults possible. The ability of the system to supply information (data collection, data storage, assessment and evaluation) is demonstrated by a series of typical faults, which were found worldwide in oil and gas pipes. (orig./HP) [de

14 CFR 23.533 - Hull and main float bottom pressures.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and main float bottom pressures. 23... Water Loads § 23.533 Hull and main float bottom pressures. (a) General. The hull and main float....00213; K2=hull station weighing factor, in accordance with figure 2 of appendix I of this part; VS1...

Multifractal analysis of managed and independent float exchange rates

Science.gov (United States)

Stošić, Darko; Stošić, Dusan; Stošić, Tatijana; Stanley, H. Eugene

2015-06-01

We investigate multifractal properties of daily price changes in currency rates using the multifractal detrended fluctuation analysis (MF-DFA). We analyze managed and independent floating currency rates in eight countries, and determine the changes in multifractal spectrum when transitioning between the two regimes. We find that after the transition from managed to independent float regime the changes in multifractal spectrum (position of maximum and width) indicate an increase in market efficiency. The observed changes are more pronounced for developed countries that have a well established trading market. After shuffling the series, we find that the multifractality is due to both probability density function and long term correlations for managed float regime, while for independent float regime multifractality is in most cases caused by broad probability density function.

Offshore Fish Community: Ecological Interactions

Science.gov (United States)

The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

Offshore Wind Energy Cost Modeling Installation and Decommissioning

CERN Document Server

Kaiser, Mark J

2012-01-01

Offshore wind energy is one of the most promising and fastest growing alternative energy sources in the world. Offshore Wind Energy Cost Modeling provides a methodological framework to assess installation and decommissioning costs, and using examples from the European experience, provides a broad review of existing processes and systems used in the offshore wind industry. Offshore Wind Energy Cost Modeling provides a step-by-step guide to modeling costs over four sections. These sections cover: ·Background and introductory material, ·Installation processes and vessel requirements, ·Installation cost estimation, and ·Decommissioning methods and cost estimation.  This self-contained and detailed treatment of the key principles in offshore wind development is supported throughout by visual aids and data tables. Offshore Wind Energy Cost Modeling is a key resource for anyone interested in the offshore wind industry, particularly those interested in the technical and economic aspects of installation and decom...

Offshore petroleum engineering task force report

International Nuclear Information System (INIS)

Ruelokke, M.

1999-05-01

The Offshore Petroleum Engineering Task Force was established in July 1998 in response to concerns about Newfoundland and Labrador's share of offshore petroleum engineering activity, with the aim of determining the current capability of the local sector, the demand for such companies and individuals until the year 2010, their capability to grow over that time-frame, and requirements in order to achieve that growth. The report summarizes the analysis undertaken by the Task Force as well as the conclusions it reached and associated recommendations. Section two provides an overview of the offshore engineering activity, including its origins, structure, and key success factors, and its also provides a profile of the industry, internationally, in Canada and in Newfoundland. Section three presents an analysis of the future demand for offshore engineering in Newfoundland until 2010, based on three development scenarios. Section four based on a Consulting Engineers of Newfoundland and Labrador (CENL) survey, establishes the present offshore engineering capacity and capabilities within the province. Section five examines current education and training programs and their ability to respond to future demands. Section six summarizes the conclusions of the analysis and presents recommendations designed to facilitate and promote the development of the local offshore engineering industry. 6 figs

Grid Integration of Offshore Wind | Wind | NREL

Science.gov (United States)

Grid Integration of Offshore Wind Grid Integration of Offshore Wind Much can be learned from the existing land-based integration research for handling the variability and uncertainty of the wind resource Arklow Bank offshore wind park consists of seven GE Wind 3.6-MW wind turbines. Integration and

A novel grounded to floating admittance converter with electronic control

Science.gov (United States)

Prasad, Dinesh; Ahmad, Javed; Srivastava, Mayank

2018-01-01

This article suggests a new grounded to floating admittance convertor employing only two voltage differencing transconductance amplifiers (VDTAs). The proposed circuit can convert any arbitrary grounded admittance into floating admittance with electronically controllable scaling factor. The presented converter enjoys the following beneficial: (1) no requirement of any additional passive element (2) scaling factor can be tuned electronically through bias currents of VDTAs (3) no matching constraint required (4) low values of active/passive sensitivity indexes and (5) excellent non ideal behavior that indicates no deviation in circuit behavior even under non ideal environment. Application of the proposed configuration in realization of floating resistor and floating capacitor has been presented and the workability of these floating elements has been confirmed by active filter design examples. SPICE simulations have been performed to demonstrate the performance of the proposed circuits.

Validation of a FAST Model of the SWAY Prototype Floating Wind Turbine

Energy Technology Data Exchange (ETDEWEB)

Koh, J. H. [Nanyang Technological Univ. (Singapore); Ng, E. Y. K. [Nanyang Technological Univ. (Singapore); Robertson, Amy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jonkman, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States); Driscoll, Frederick [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-06-01

As part of a collaboration of the National Renewable Energy Laboratory (NREL) and SWAY AS, NREL installed scientific wind, wave, and motion measurement equipment on the spar-type 1/6.5th-scale prototype SWAY floating offshore wind system. The equipment enhanced SWAY's data collection and allowed SWAY to verify the concept and NREL to validate a FAST model of the SWAY design in an open-water condition. Nanyang Technological University (NTU), in collaboration with NREL, assisted with the validation. This final report gives an overview of the SWAY prototype and NREL and NTU's efforts to validate a model of the system. The report provides a summary of the different software tools used in the study, the modeling strategies, and the development of a FAST model of the SWAY prototype wind turbine, including justification of the modeling assumptions. Because of uncertainty in system parameters and modeling assumptions due to the complexity of the design, several system properties were tuned to better represent the system and improve the accuracy of the simulations. Calibration was performed using data from a static equilibrium test and free-decay tests.

Conference on offshore wind power in France and Germany

International Nuclear Information System (INIS)

Meyer, Ronny; Furois, Timothee; Nolte, Nico; Lanoe, Frederic; Lehmann-Matthaei, Bjoern; Ifflaender, Andree; Courcambeck, Alexandre; Giese, Norbert; Kavafyan, Philippe; Bjaert, Niels; Wagner, Andreas; Guillet, Jerome

2014-01-01

The French-German office for Renewable energies (OFAEnR) organised a conference on offshore wind power in France and Germany. In the framework of this French-German exchange of experience, about 120 participants exchanged views on the planning and authorisation procedures implemented in both countries and on the installation, connection to the grid and maintenance of offshore wind turbines. environmental impacts and usage conflicts linked with offshore wind farms exploitation were addressed as well. This document brings together the available presentations (slides) made during this event: 1 - Update: Offshore Wind In Germany (Ronny Meyer); 2 - Offshore wind development in France (Timothee Furois); 3 - The Licensing Procedure for Offshore Wind Farms in the German EEZ (Nico Nolte); 4 - Spatial Planning and Permitting in France: What leverage for more efficiency? (Frederic Lanoe); 5 - Results of 10 years environmental research on FINO-platforms (Bjoern Lehmann-Matthaei); 6 - Offshore Grid Connection - Status Quo and Overview (Andree Ifflaender); 7 - Grid connection of Offshore Wind in France: Situation, perspectives and recommendations (Alexandre Courcambeck); 8 - Controlling risks and warranting safety: Best practices for the installation, exploitation and maintenance of offshore wind turbines (Norbert Giese); 9 - Offshore wind Bremerhaven experience: An essential asset for the development of a complete Wind Offshore industry in France (Philippe Kavafyan); 10 - Standardizing and Cost Reduction -Lessons Learned from London Array (Niels Bjaert); 11 - Offshore Wind energy in Germany: System Benefits and Cost Reduction Potentials. Presentation of study results from prognos/fichtner and Fraunhofer-IWeS (Andreas Wagner); 12 - Offshore Wind energy financing - opportunities and risks (Jerome Guillet)

Denmark - supplier of competitive offshore wind solutions. Megavind's strategy for offshore wind research, development and demonstration

Energy Technology Data Exchange (ETDEWEB)

2010-12-15

In May 2006, the Danish Government presented a report on promoting environmentally effective technology and established a number of innovative partnerships. The partnerships intend to strengthen public-private cooperation between the state, industry, universities and venture capital to accelerate innovation for a number of green technologies. The partnership for wind energy is called Megavind. Megavind's strategy for offshore wind describes the offshore challenges and suggests research, development and demonstration (RD and D) priorities to enable offshore wind power become to competitive with other energy technologies. The strategy lists key recommendations as well as key thematic priorities and for each of these a number of RD and D priorities. Under each thematic priority references are made to the European Strategic Energy Technology plan (SET-plan), which prioritises offshore wind RD and D in Europe. (LN)

The offshore benthic fish community

Science.gov (United States)

Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

2014-01-01

Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

IFREMER-ADEME colloquium 'Offshore renewable energies: offshore wind energy - sea currents and waves. Collection of abstracts

International Nuclear Information System (INIS)

2004-10-01

This document contains programme and abstracts of contributions presented during a colloquium. These contributions first addresses the context, and regulatory and economic aspects of offshore wind and sea energy: specificities related to the Public Maritime Domain for the implantation of offshore wind turbines, economy of sea energies within a perspective of de-carbonation of the world energy sector, case of offshore wind turbines and assessment of economic impacts of the implantation of sea renewable energy production units, financing stakes for offshore wind energy projects. A second set of contribution addresses the state-of -the-art and feedbacks for offshore wind energy installations. The third set addresses the assessment of resource potential, measurements, models and production prediction for offshore wind energy: case of French coasts, use of radar for remote sensing, wind climatology modelling, data acquisition for wind farm and data processing. The fourth set of contributions addresses the state-of-the-art, feedback, and R and D for sea current energy, while the fifth one addressed the same aspects for sea wave energy. Technology, installations, maintenance and storage in the field of wind energy are then addressed, and the last set deals with environmental and social-economical impacts of sea renewable energies

The onshore influence of offshore fresh groundwater

Science.gov (United States)

Knight, Andrew C.; Werner, Adrian D.; Morgan, Leanne K.

2018-06-01

Freshwater contained within the submarine extensions of coastal aquifers is increasingly proposed as a freshwater source for coastal communities. However, the extent to which offshore freshwater supports onshore pumping is currently unknown on a global scale. This study provides the first attempt to examine the likely prevalence of situations where offshore freshwater influences onshore salinities, considering various sites from around the world. The groundwater conditions in twenty-seven confined and semi-confined coastal aquifers with plausible connections to inferred or observed offshore freshwater are explored. The investigation uses available onshore salinities and groundwater levels, and offshore salinity knowledge, in combination with analytical modelling, to develop simplified conceptual models of the study sites. Seven different conceptual models are proposed based on the freshwater-saltwater extent and insights gained from analytical modelling. We consider both present-day and pre-development conditions in assessing potential modern contributions to offshore fresh groundwater. Conceptual models also include interpretations of whether offshore freshwater is a significant factor influencing onshore salinities and well pumping sustainability. The results indicate that onshore water levels have declined between pre-development and present-day conditions in fourteen of the fifteen regions for which pre-development data are available. Estimates of the associated steady-state freshwater extents show the potential for considerable offshore fresh groundwater losses accompanying these declines. Both present-day and pre-development heads are insufficient to account for the observed offshore freshwater in all cases where adequate data exist. This suggests that paleo-freshwater and/or aquifer heterogeneities contribute significantly to offshore freshwater extent. Present-day heads indicate that active seawater intrusion (SWI) will eventually impact onshore pumping

Developments in offshore technology. Entwicklungen in der Offshoretechnik

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

This book contains the summarized lectures held on the 8th of October, 1981 within the first status Seminar 'Offshore technology' which was organized by the Federal Minstry for Research and Technology. Contents are divided into: 1. Offshore-natural gas liquefaction, conveying systems. Offshore-tanker charging with supercold liquiefied gases; development of LNG-offshore - convayance systems; 2.) Development of components and installations in offshore structures: mooving-measuring- and monitoring systems for the installation of the EPOS deck; underwater-piling with a hydraulic-pile hammer; cast steel nodes for offshore-structures (material, calculation, design); 3.) underwater tools: the underwater-working system SUPRA; test results and experience with the unmanned UW-instrument-carrier FUGE; development of a mobile diver assistance vehicle for inspection and maintenance duties; 4.) underwater-pipeline-technique: flexible offshore-pipeline/continuous production and assembly, pipeline assembly at sea according to the J-Method with flash-welding technique; construction and testing of UWAG I (underwater working device) for embedding cables and pipes in the ocean soil.

Understanding public responses to offshore wind power

International Nuclear Information System (INIS)

Haggett, Claire

2011-01-01

This paper is about understanding the role and importance of public responses to offshore wind power. It builds on a framework for understanding social acceptance and opposition to onshore turbines, and reviews the emerging research on offshore wind. While less is known about how people will respond to offshore than onshore wind, there is now an emerging body of research. From this literature, several common factors which influence responses have emerged and are discussed here: the (continued) role of visual impact; place attachment to the local area; lack of tangible benefits; relationships with developers and outsiders; and the role of the planning and decision-making systems. The paper argues that, as with onshore developments, the public should be included in decision-making about offshore wind farms, and that they have a key role which should not be underestimated. The paper concludes with some thoughts about the means to involve people and how effected communities might be effectively acknowledged, identified and engaged. - Research Highlights: →Comprehensive review of public responses to offshore wind literature. →Applies key lessons and analytic insights from onshore wind to offshore wind. →Emphasizes the role and importance of the public in the planning and implementation of offshore wind energy.

Global Production: The Case of Offshore Programming

DEFF Research Database (Denmark)

Nørbjerg, Jacob; Havn, Erling; Bansler, Jørgen P.

1997-01-01

of software is no exception.In this paper, we present a newly started research project on offshore program-ming, that is the practice of sending software development “offshore,” to India or other low wage areas. The project focuses on the organisation of offshore program-ming and, particularly, on the role...

Socio-economic Impacts—Offshore Activities/Energy

DEFF Research Database (Denmark)

Halsnæs, Kirsten; Drews, Martin; Clausen, Niels-Erik

2016-01-01

sector and renewable electricity generation—mainly from offshore wind—is increasing. Energy and offshore activities in the North Sea are critically vulnerable to climate change along the full supply chain. The major vulnerabilities for offshore installations like rigs, offshore wind energy and pipelines......, it is highly uncertain how much the future potential of other renewable energy sources such as wind, solar, terrestrial biomass, or emerging technologies like wave, tidal or marine biomass could be positively or negatively affected. Due to the different national energy supply mixes the vulnerability to climate......-related impacts will vary among North Sea countries. To ensure safe and reliable future operations comprehensive and systematic risk assessments are therefore needed which account for, for example, the high integration of power systems in the region....

Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization.

Science.gov (United States)

Li, Min; Zhang, John Zenghui; Xia, Fei

2016-04-12

Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

Floating Inductance and FDNR Using Positive Polarity Current Conveyors

Directory of Open Access Journals (Sweden)

K. Pal

2004-01-01

Full Text Available A generalized circuit based on five positive polarity second-generation current conveyors is introduced. The circuit simulates a floating inductance, capacitor floatation circuit and floating fdnr. All these circuits use grounded capacitors.

Sabrewing: A lightweight architecture for combined floating-point and integer arithmetic

NARCIS (Netherlands)

Bruintjes, Tom; Walters, K.H.G.; Gerez, Sabih H.; Molenkamp, Egbert; Smit, Gerardus Johannes Maria

In spite of the fact that floating-point arithmetic is costly in terms of silicon area, the joint design of hardware for floating-point and integer arithmetic is seldom considered. While components like multipliers and adders can potentially be shared, floating-point and integer units in

近海风电机结构动力响应极值预报%Prediction of Structural Dynamic Response Extreme Values of Offshore Wind Turbine

Institute of Scientific and Technical Information of China (English)

王立夫

2017-01-01

鉴于国内外在预报风浪共同作用下近海风电机的极限结构动力响应方面仍然面临挑战的现状,提出用最小二乘法高效精确地求解广义柏拉图分布中的待定参数,预报某5 MW漂浮式风电机塔筒平台接合处的前后向弯矩极值,并用蒙特卡罗仿真和诊断图证明了最小二乘法与传统的矩方法相比的优越性.可为浮式海上风电机的结构设计提供参考.%Due to the fact that it is still a challenge at both home and abroad on how to predict the extreme structural dynamic responses of an offshore wind turbine under the con current action of wind and waves,the method of least squares is used to more efficiently and accurately estimate the unknown parameters in the Generalized Pareto distribution so that the extreme values of the fore-aft bending moments at the tower-Spar interface of a 5 MW floating wind turbine are predicted.Monte Carlo simulation and diagnostic plots are used to test the advantages of the method of least squares over the traditional method of moments.The new method proposed will become a powerful tool for the people in their structural design of a floating offshore wind turbine.

Production of floating pellets using appropriate methods | Suleiman ...

African Journals Online (AJOL)

The study investigated into the use of floating materials like candle wax, yeast and baking powder to achieve pellet buoyancy. Ten diets were formulated with incorporation of floating agents; Diet I-YBCT- (yeast-baking powder in cold water -toasted), Diet II-YBCU- (yeast-baking powder in cold water -untoasted) Diet III ...

Operational management of offshore energy assets

Science.gov (United States)

Kolios, A. J.; Martinez Luengo, M.

2016-02-01

Energy assets and especially those deployed offshore are subject to a variety of harsh operational and environmental conditions which lead to deterioration of their performance and structural capacity over time. The aim of reduction of CAPEX in new installations shifts focus to operational management to monitor and assess performance of critical assets ensuring their fitness for service throughout their service life and also to provide appropriate and effective information towards requalification or other end of life scenarios, optimizing the OPEX. Over the last decades, the offshore oil & gas industry has developed and applied various approaches in operational management of assets through Structural Health and Condition Monitoring (SHM/CM) systems which can be, at a certain level, transferable to offshore renewable installations. This paper aims to highlight the key differences between offshore oil & gas and renewable energy assets from a structural integrity and reliability perspective, provide a comprehensive overview of different approaches that are available and applicable, and distinguish the benefits of such systems in the efficient operation of offshore energy assets.

Fine Slicing of the Value Chain and Offshoring of Essential Activities

DEFF Research Database (Denmark)

Linares-Navarro, Esmeralda; Pedersen, Torben; Pla-Barber, José

2014-01-01

The offshoring of more advanced activities is increasing and a debate about the limits of offshoring has emerged. Companies are fine-slicing their value chains, and moving beyond the offshoring of peripheral and non-core activities to the offshoring of advanced and essential activities that are c......The offshoring of more advanced activities is increasing and a debate about the limits of offshoring has emerged. Companies are fine-slicing their value chains, and moving beyond the offshoring of peripheral and non-core activities to the offshoring of advanced and essential activities...... that companies are redefining their core activities and in this process, some essential activities previously viewed as core activities are being detached from the core, and they become more offshorable. The study uses a sample of 565 offshoring operations conducted by 263 multinational companies from 15...... European countries. A logistic regression was used to analyze the relationship between the activities offshored (non-core versus essential activities) and the offshoring mode implemented (captive offshoring versus offshore outsourcing). We find that essential activities are typically offshored using...

Application of the Aero-Hydro-Elastic Model, HAWC2-WAMIT, to Offshore Data from Floating Power Plants Hybrid Wind- and Wave-Energy Test Platform, P37

DEFF Research Database (Denmark)

Bellew, Sarah; Yde, Anders; Verelst, David Robert

2014-01-01

numerical models, which can combine the aerodynamic, hydrodynamic, structural exibility and mooring components. Very little oshore data exists, however, in order to validate these numerical models. Floating Power Plant are the developers of a oating, hybrid wind- and wave-energy device. The device uses...... the pitching wave energy devices, not only to increase and smooth the power output from the platform, but also to take the energy from the waves in a controlled manner, resulting in a stable platform for the wind turbine and a safe harbour for O&M. They are currently developing the nal design for their rst...... full-scale prototype, the P80, which has a width of 80 m. As part of the development, Floating Power Plant have completed 4 oshore test-phases (totalling over 2 years oshore operation) on a 37 m wide scaled test device, the P37. This paper focuses on the comparison of one of the leading numerical...

Pricing offshore wind power

International Nuclear Information System (INIS)

Levitt, Andrew C.; Kempton, Willett; Smith, Aaron P.; Musial, Walt; Firestone, Jeremy

2011-01-01

Offshore wind offers a very large clean power resource, but electricity from the first US offshore wind contracts is costlier than current regional wholesale electricity prices. To better understand the factors that drive these costs, we develop a pro-forma cash flow model to calculate two results: the levelized cost of energy, and the breakeven price required for financial viability. We then determine input values based on our analysis of capital markets and of 35 operating and planned projects in Europe, China, and the United States. The model is run for a range of inputs appropriate to US policies, electricity markets, and capital markets to assess how changes in policy incentives, project inputs, and financial structure affect the breakeven price of offshore wind power. The model and documentation are made publicly available. - Highlights: → We calculate the Breakeven Price (BP) required to deploy offshore wind plants. → We determine values for cost drivers and review incentives structures in the US. → We develop 3 scenarios using today's technology but varying in industry experience. → BP differs widely by Cost Scenario; relative policy effectiveness varies by stage. → The low-range BP is below regional market values in the Northeast United States.

Offshore Supply Industry Dynamics

DEFF Research Database (Denmark)

Roslyng Olesen, Thomas

This report is part of the research project “The competitive challenges and strategic development possibilities for The Blue Denmark”, which was launched in 2014. The project is funded by the Danish Maritime Fund and carried out by researchers at CBS Maritime which is a Business in Society Platform...... with companies in the maritime sector. This report “Offshore Supply Industry Dynamics – Business strategies in the offshore supply industry” is the second report in mapping project D. It examines the markets and business strategies of various suppliers and furthermore presents an analysis of the challenges...... at Copenhagen Business School with a focus on value creation in the maritime industries. The project embraces various maritime segments from shipping and offshore to ports and suppliers. The research questions for the individual projects have been formulated by researchers at CBS Maritime in cooperation...

Offshore rectenna feasbility

Science.gov (United States)

Freeman, J. W.; Hervey, D.; Glaser, P.

1980-01-01

A preliminary study of the feasibility and cost of an offshore rectenna to serve the upper metropolitan east coast was performed. A candidate site at which to build a 5 GW rectenna was selected on the basis of proximity to load centers, avoidance of shipping lanes, sea floor terrain, and relocated conditions. Several types of support structures were selected for study based initially on the reference system rectenna concept of a wire mesh ground screen and dipoles each with its own rectifier and filter circuits. Possible secondary uses of an offshore rectenna were examined and are evaluated.

Gela offshore field

Energy Technology Data Exchange (ETDEWEB)

Pagliughi, G

1965-06-01

The field of Gela, off the southern shore of Sicily, is the only producing offshore field in the Mediterranean. It produces from Triassic dolimite limestones of 434-m thickness, water level at -3517 m. It is a water-drive reservoir producing 10/sup 0/F API oil and has 79 wells, some of them on shore. Most offshore wells are directional wells from shore; there are also 2 fixed platforms and a special mobile platform. The wells are on pump (stroke, 72 in.; capacity 200 tons per day). The crude goes directly to a combination refinery-petrochemical complex at Gela.

Offshore Energy Knowledge Exchange Workshop Report

Energy Technology Data Exchange (ETDEWEB)

none,

2012-04-12

A report detailing the presentations and topics discussed at the Offshore Energy Knowledge Exchange Workshop, an event designed to bring together offshore energy industry representatives to share information, best practices, and lessons learned.

From tiny microalgae to huge biorefineries

OpenAIRE

Gouveia, L.

2014-01-01

Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

Attitude and acceptance of offshore wind farms

DEFF Research Database (Denmark)

Ladenburg, Jacob; Möller, B.

2011-01-01

farms attributes on attitude towards offshore wind farms. The results point towards that the travel time and the attributes of the nearest offshore wind farm influence the attitude significantly. Travel time has mixed effects on the attitude, whilst offshore wind farms with many turbines generate more...... a novel contribution to this field. First of all, we give a thorough review of the studies that have analysed the relation between experience with wind turbines and attitude. In addition, we supplement the review by analysing the effect of travel distance to the nearest offshore wind farm and the wind...

The Capabilities of the Offshore Middlemen

DEFF Research Database (Denmark)

Mahnke, Volker; Wareham, Jonathan

preliminary theoretical justification for the emergence of offshore intermediaries; describe how and why they develop intermediation capabilities; and offer initial evidence substantiating their function and processes in intermediating transnational offshoring relationships in software development...

Towards Interactive Steering of a Very Large Floating Structure Code by Using HPC Parallelisation Strategies

KAUST Repository

Frisch, Jerome; Gao, Ruiping; Mundani, Ralf-Peter; Wang, Chien Ming; Rank, Ernst

2012-01-01

Very large floating structures (VLFSs) have been used for broad applications such as floating storage facilities, floating piers, floating bridges, floating airports, entertainment facilities, even habitation, and other purposes. Owing to its small

[Treatment of Persistent Somatoform Pain Disorder by Floating Needle Therapy and Duloxetine].

Science.gov (United States)

Ren, Wan-wen; Zhou, Zhi-ying; Xu, Mi-mi; Long, Sen; Tang, Guang-zheng; Mao, Hong-jing; Chen, Shu-lin

2016-02-01

To evaluate clinical effect and safety of floating needle therapy and duloxetine in treating patients with persistent somatoform pain disorder (PSPD). Totally 108 PSPD patients were randomly assigned to the floating needle treatment group, the duloxetine treatment group, and the placebo treatment group, 36 in each group. Patients in the floating needle treatment group received floating needle therapy and placebo. Those in the duloxetine treatment group received duloxetine and simulated floating needle therapy. Those in the placebo treatment group received the placebo and simulated floating needle therapy. All treatment lasted for six weeks. Efficacy and adverse reactions were evaluated using Simple McGill pain scale (SF-MPQ) and Treatment Emergent Symptom Scale (TESS) before treatment and immediately after treatment, as well as at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Hamilton Depression Scale (HAMD, 17 items), Hamilton Anxiety Scale (HAMA) were assessed before treatment and at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Patients in the floating needle treatment group and the duloxetine treatment group with the total reducing score rate of SF-MPQ in Pain Rating index (PRI) ≥ 50% after 6 weeks' treatment were involved in the follow-up study. (1) Compared with the same group before treatment, SF-MPQ score, HAMD score and HAMA total scores all decreased in all the three groups at the end of 1st, 2nd, 4th, and 6th week of treatment (P floating needle treatment group (P floating needle treatment group significantly decreased after 1, 2, 4, and 6 weeks of treatment (P floating needle treatment group, 17 (50.0%) in the duloxetine treatment group, and 7 (21.2%) in the placebo treatment group. Compared with the placebo treatment group, the incidence of adverse reaction increased in the duloxetine treatment group (χ² = 6.04, P floating needle treatment group (χ² = 14.9, P floating needle treatment group and 17

Development and Characterization of Novel Floating-Mucoadhesive Tablets Bearing Venlafaxine Hydrochloride

Directory of Open Access Journals (Sweden)

Raghvendra Misra

2016-01-01

Full Text Available The present investigation is concerned about the development of floating bioadhesive drug delivery system of venlafaxine hydrochloride which after oral administration exhibits a unique combination of floating and bioadhesion to prolong gastric residence time and increase drug bioavailability within the stomach. The floating bioadhesive tablets were prepared by the wet granulation method using different ratios of hydroxypropyl methyl cellulose (HPMC K4MCR and Carbopol 934PNF as polymers. Sodium bicarbonate (NaHCO3 and citric acid were used as gas (CO2 generating agents. Tablets were characterized for floating properties, in vitro drug release, detachment force, and swelling index. The concentration of hydroxypropyl methyl cellulose and Carbopol 934PNF significantly affects the in vitro drug release, floating properties, detachment force, and swelling properties of the tablets. The optimized formulation showed the floating lag time 72±2.49 seconds and duration of floating 24.50±0.74 hr. The in vitro release studies and floating behavior were studied in simulated gastric fluid (SGF at pH 1.2. Different drug release kinetics models were also applied. The in vitro drug release from tablets was sufficiently sustained (more than 18 hr and the Fickian transports of the drug from the tablets were confirmed. The radiological evidence suggests that the tablets remained buoyant and altered position in the stomach of albino rabbit and mean gastric residence time was prolonged (more than > 6 hr.

Environmental risk in the offshore industry

International Nuclear Information System (INIS)

Woods, I.T.; Shirley, D.; Bottelberghs, P.H.

1991-01-01

The subject of oil pollution of the sea by the offshore industry is topical as a result of recent incidents both in the U.K. and overseas. While these incidents have primarily involved crude carriers, it has led to pressure to quantify the risk to the environment from the offshore industry in general. In this paper a method for the assessment of the frequency and size of oil spills from offshore installations is presented. It relies on previously reported spills to determine spill size/frequency information for a range of offshore activities, such as transport by pipeline, drilling and processing. Modification factors are used so local conditions, such as the number of wells drilled, throughput and well depth, can be considered in the assessment of the oil spill risk from a particular installation

Formulation, release characteristics, and bioavailability study of gastroretentive floating matrix tablet and floating raft system of Mebeverine HCl.

Science.gov (United States)

El Nabarawi, Mohamed A; Teaima, Mahmoud H; Abd El-Monem, Rehab A; El Nabarawy, Nagla A; Gaber, Dalia A

2017-01-01

To prolong the residence time of dosage forms within the gastrointestinal tract until all drug is released at the desired rate is one of the real challenges for oral controlled-release drug delivery systems. This study was designed to develop a controlled-release floating matrix tablet and floating raft system of Mebeverine HCl (MbH) and evaluate different excipients for their floating behavior and in vitro controlled-release profiles. Oral pharmacokinetics of the optimum matrix tablet, raft system formula, and marketed Duspatalin ® 200 mg retard as reference were studied in beagle dogs. The optimized tablet formula (FT-10) and raft system formula (FRS-11) were found to float within 34±5 sec and 15±7 sec, respectively, and both remain buoyant over a period of 12 h in simulated gastric fluid. FT-10 (Compritol/HPMC K100M 1:1) showed the slowest drug release among all prepared tablet formulations, releasing about 80.2% of MbH over 8 h. In contrast, FRS-11 (Sodium alginate 3%/HPMC K100M 1%/Precirol 2%) had the greatest retardation, providing sustained release of 82.1% within 8 h. Compared with the marketed MbH product, the C max of FT-10 was almost the same, while FRS-11 maximum concentration was higher. The t max was 3.33, 2.167, and 3.0 h for marketed MbH product, FT-10, and FRS-11, respectively. In addition, the oral bioavailability experiment showed that the relative bioavailability of the MbH was 104.76 and 116.01% after oral administration of FT-10 and FRS-11, respectively, compared to marketed product. These results demonstrated that both controlled-released floating matrix tablet and raft system would be promising gastroretentive delivery systems for prolonging drug action.

Floating cultivation of marine cyanobacteria using coal fly ash

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, M.; Yoshida, E.; Takeyama, H.; Matsunaga, T. [Tokyo University of Agriculture and Technology, Tokyo (Japan). Dept. of Biotetechnology

2000-07-01

The aim was to develop improved methodologies for bulk culturing of biotechnologically useful marine cyanobacteria in the open ocean. The viability of using coal fly ash (CFA) blocks as the support medium in a novel floating culture system for marine microalgae was investigated. The marine cyanobacterium Synechococcus sp. NKBC 040607 was found to adhere to floating CFA blocks in liquid culture medium. The marine cyanobacterium Synechococcus sp. NKBG 042902 weakly adhered to floating CFA blocks in BG-11 medium. Increasing the concentration of calcium ion in the culture medium enhanced adherence to CFA blocks.

Free-Floating Iris Cyst in a Patient with Recurrent Iritis

Directory of Open Access Journals (Sweden)

Joanne M.Y. Teong

2015-06-01

Full Text Available Purpose: We describe an unusual clinical finding of a free-floating iris cyst in a patient with recurrent iritis. Method: The clinical finding of a free-floating iris cyst was recorded using slit-lamp photography. Results: A 39-year-old male with a 5-year history of recurrent right iritis was found to have a small mobile iris cyst within his right anterior chamber, first identified 3 years ago. The patient did not experience any discomfort or visual symptoms resulting from the cyst. Conclusion: Surgical removal is not indicated for asymptomatic non-progressive free-floating iris cysts. The significance of a free-floating iris cyst in the setting of recurrent iritis remains unknown.

Impact of associated injuries in the Floating knee: A retrospective study

Science.gov (United States)

Rethnam, Ulfin; Yesupalan, Rajam S; Nair, Rajagopalan

2009-01-01

Background Floating knee injuries are usually associated with other significant injuries. Do these injuries have implications on the management of the floating knee and the final outcome of patients? Our study aims to assess the implications of associated injuries in the management and final outcome of floating knee. Methods 29 patients with floating knees were assessed in our institution. A retrospective analysis of medical records and radiographs were done and all associated injuries were identified. The impact of associated injuries on delay in initial surgical management, delay in rehabilitation & final outcome of the floating knee were assessed. Results 38 associated injuries were noted. 7 were associated with ipsilateral knee injuries. Lower limb injuries were most commonly associated with the floating knee. Patients with some associated injuries had a delay in surgical management and others a delay in post-operative rehabilitation. Knee ligament and vascular injuries were associated with poor outcome. Conclusion The associated injuries were quite frequent with the floating knee. Some of the associated injuries caused a delay in surgical management and post-operative rehabilitation. In assessment of the final outcome, patients with associated knee and vascular injuries had a poor prognosis. Majority of the patients with associated injuries had a good or excellent outcome. PMID:19144197

Floating Collection in an Academic Library: An Audacious Experiment That Succeeded

Science.gov (United States)

Coopey, Barbara; Eshbach, Barbara; Notartomas, Trish

2016-01-01

Can a floating collection thrive in a large multicampus academic research library? Floating collections have been successful in public libraries for some time, but it is uncommon for academic libraries and unheard of for a large academic library system. This article will discuss the investigation into the feasibility of a floating collection at…

Offshore Membrane Enclosures for Growing Algae (OMEGA: A System for Biofuel Production, Wastewater Treatment, and CO2 Sequestration

Science.gov (United States)

Trent, Jonathan; Embaye, Tsegereda; Buckwalter, Patrick; Richardson, Tra-My; Kagawa, Hiromi; Reinsch, Sigrid; Martis, Mary

2010-01-01

We are developing Offshore Membrane Enclosures for Growing Algae (OMEGA). OMEGAs are closed photo-bioreactors constructed of flexible, inexpensive, and durable plastic with small sections of semi-permeable membranes for gas exchange and forward osmosis (FO). Each OMEGA modules is filled with municipal wastewater and provided with CO2 from coastal CO2 sources. The OMEGA modules float just below the surface, and the surrounding seawater provides structural support, temperature control, and mixing for the freshwater algae cultures inside. The salinit7 gradient from inside to outside drives forward osmosis through the patches of FO membranes. This concentrates nutrients in the wastewater, which enhances algal growth, and slowly dewaters the algae, which facilitates harvesting. Thy concentrated algal biomass is harvested for producing biofuels and fertilizer. OMEGA system cleans the wastewater released into the surrounding coastal waters and functions as a carbon sequestration system.

Measuring the Coefficient of Friction of a Small Floating Liquid Marble.

Science.gov (United States)

Ooi, Chin Hong; Nguyen, Anh Van; Evans, Geoffrey M; Dao, Dzung Viet; Nguyen, Nam-Trung

2016-12-02

This paper investigates the friction coefficient of a moving liquid marble, a small liquid droplet coated with hydrophobic powder and floating on another liquid surface. A floating marble can easily move across water surface due to the low friction, allowing for the transport of aqueous solutions with minimal energy input. However, the motion of a floating marble has yet to be systematically characterised due to the lack of insight into key parameters such as the coefficient of friction between the floating marble and the carrier liquid. We measured the coefficient of friction of a small floating marble using a novel experimental setup that exploits the non-wetting properties of a liquid marble. A floating liquid marble pair containing a minute amount magnetite particles were immobilised and then released in a controlled manner using permanent magnets. The capillarity-driven motion was analysed to determine the coefficient of friction of the liquid marbles. The "capillary charge" model was used to fit the experimental results. We varied the marble content and carrier liquid to establish a relationship between the friction correction factor and the meniscus angle.

10 CFR 150.7 - Persons in offshore waters not exempt.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Persons in offshore waters not exempt. 150.7 Section 150.7... AGREEMENT STATES AND IN OFFSHORE WATERS UNDER SECTION 274 Continued Commission Regulatory Authority in Offshore Waters § 150.7 Persons in offshore waters not exempt. Persons in offshore waters are not exempt...

The floating knee: epidemiology, prognostic indicators & outcome following surgical management

OpenAIRE

Yesupalan Rajam S; Rethnam Ulfin; Nair Rajagopalan

2007-01-01

Abstract Background Floating Knee injuries are complex injuries. The type of fractures, soft tissue and associated injuries make this a challenging problem to manage. We present the outcome of these injuries after surgical management. Methods 29 patients with floating knee injuries were managed over a 3 year period. This was a prospective study were both fractures of the floating knee injury were surgically fixed using different modalities. The associated injuries were managed appropriately. ...

Water-hydraulic power transmission for offshore wind farms

NARCIS (Netherlands)

Diepeveen, N.F.B.; Jarquin Laguna, A.; Kempenaar, A.S.

2012-01-01

The current state of the art of offshore wind turbine power transmission technology is expensive, heavy and maintenance intensive. The Delft Offshore Turbine project considers a radically new concept for power transmission in an offshore wind farm: using seawater as power transmission medium. For

Offshore Wind Energy Systems Engineering Curriculum Development

Energy Technology Data Exchange (ETDEWEB)

McGowan, Jon G. [Univ. of Massachusetts, Amherst, MA (United States); Manwell, James F. [Univ. of Massachusetts, Amherst, MA (United States); Lackner, Matthew A. [Univ. of Massachusetts, Amherst, MA (United States)

2012-12-31

Utility-scale electricity produced from offshore wind farms has the potential to contribute significantly to the energy production of the United States. In order for the U.S. to rapidly develop these abundant resources, knowledgeable scientists and engineers with sound understanding of offshore wind energy systems are critical. This report summarizes the development of an upper-level engineering course in "Offshore Wind Energy Systems Engineering." This course is designed to provide students with a comprehensive knowledge of both the technical challenges of offshore wind energy and the practical regulatory, permitting, and planning aspects of developing offshore wind farms in the U.S. This course was offered on a pilot basis in 2011 at the University of Massachusetts and the National Renewable Energy Laboratory (NREL), TU Delft, and GL Garrad Hassan have reviewed its content. As summarized in this report, the course consists of 17 separate topic areas emphasizing appropriate engineering fundamentals as well as development, planning, and regulatory issues. In addition to the course summary, the report gives the details of a public Internet site where references and related course material can be obtained. This course will fill a pressing need for the education and training of the U.S. workforce in this critically important area. Fundamentally, this course will be unique due to two attributes: an emphasis on the engineering and technical aspects of offshore wind energy systems, and a focus on offshore wind energy issues specific to the United States.

High voltage switches having one or more floating conductor layers

Science.gov (United States)

Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

2015-11-24

This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

Offshoring in textile industry

OpenAIRE

MONTÓN GARCÍA, JORGE

2015-01-01

[ EN] This project is about offshoring in the textile industry, focusing in the rights violated in this process, this concept can be defined as the moving of various operations of a company to another country for reasons such as lower labor costs or more favorable economic conditions in that other country. The project describes the evolution of offshoring, which started in 1960’s and has continued since then; it was characterized primarily by the transferring of factories from the develope...

Fear of Floating: Exchange Rate Flexibility Indices

OpenAIRE

Reinhart, Carmen

2001-01-01

Many emerging market countries have suffered financial crises. One view blames soft pegs for these crises. Adherents to that view suggest that countries move to corner solutions--hard pegs or floating exchange rates. We analyze the behavior of exchange rates, reserves, and interest rates to assess whether there is evidence that country practice is moving toward corner solutions. We focus on whether countries that claim they are floating are indeed doing so. We find that countries that say th...

Dynamic Response of a Floating Bridge Structure

OpenAIRE

Viuff, Thomas; Leira, Bernt Johan; Øiseth, Ole; Xiang, Xu

2016-01-01

A theoretical overview of the stochastic dynamic analysis of a floating bridge structure is presented. Emphasis is on the wave-induced response and the waves on the sea surface are idealized as a zero mean stationary Gaussian process. The first-order wave load processes are derived using linear potential theory and the structural idealization is based on the Finite Element Method. A frequency response calculation is presented for a simplified floating bridge structure example emphasising the ...

Development and evaluation of floating microspheres of curcumin in ...

African Journals Online (AJOL)

Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence and to study their effect on alloxan-induced diabetic rats. Methods: Floating microsphere were prepared by emulsion-solvent diffusion method, using hydroxylpropyl methylcellulose, chitosan and Eudragit S 100 polymer in ...

Economic Floating Waste Detectionfor Surface Cleaning Robots

Directory of Open Access Journals (Sweden)

Sumroengrit Jakkrit

2017-01-01

Full Text Available Removing waste out of water surface is a routine task and can be operated by using autonomous surface cleaning robots. This paper presents amethodoflaser-based floating waste detection for surface robot guidance when waste positions are unknown beforehand. Basing on concept of refraction and reflection of laser ray, the proposed laser-based technique is proven to be applicable on floating waste detection. The economic waste detector is constructed and mounted on the robot. Five DOF equations of motion are formulated for calculation of waste position incorporating distance measured by the laser and also the robot motion caused by external wind force as well as water surface tension. Experiments were conducted on a pond with calm water and results show that the presented economic waste detection successfully identify and locate position of plastic bottles floating on water surface within the range of 5 meters.

Boundary Spanning in Offshored Information Systems Development Projects

Science.gov (United States)

Krishnan, Poornima

2010-01-01

Recent growth in offshore outsourcing of information systems (IS) services is accompanied by managing the offshore projects successfully. Much of the project failures can be attributed to geographic and organizational boundaries which create differences in culture, language, work patterns, and decision making processes among the offshore project…

Compound floating pivot micromechanisms

Science.gov (United States)

Garcia, Ernest J.

2001-04-24

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-10-01

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.

Offshore wind resources at Danish measurement sites

Energy Technology Data Exchange (ETDEWEB)

Barthelmie, R J; Courtney, M S; Lange, B; Nielsen, M; Sempreviva, A M [Risoe National Lab., Dept. of Wind Energy and Atmospheric Physics, Roskilde (Denmark); Svenson, J; Olsen, F [SEAS, Haslev (Denmark); Christensen, T [Elsamprojekt, Fredericia (Denmark)

1999-03-01

In order to characterise wind and turbulence characteristics at prospective offshore wind energy sites, meteorological observations from a number of purpose-built offshore monitoring sites have been analyzed and compared with long wind speed time series. New analyses have been conducted on the data sets focussing on meteorology, turbulence, extreme winds and wind and wave interactions. Relationships between wind speed, turbulence and fetch are highly complex. Minimum turbulence intensity offshore is associated with wind speeds of about 12 m/s. At lower wind speeds, stability effects are important while at higher winds speeds wind and wave interactions appear to dominate. On average, turbulence intensity offshore at 48 m height is approximately 0.08 if no coastal effects are present. However, the effect of the coastal discontinuity persists in wind speed and turbulence characteristics for considerable distances offshore. The majority of the adjustment of appears to occur within 20 km of the coast. (au)

Formulation and evaluation of glipizide floating-bioadhesive tablets

Directory of Open Access Journals (Sweden)

Jayvadan K. Patel

2010-10-01

Full Text Available The purpose of this study was formulation and in vitro evaluation of floating-bioadhesive tablets to lengthen the stay of glipizide in its absorption area. Effervescent tablets were made using chitosan (CH, hydroxypropyl methylcellulose (HPMC, carbopolP934 (CP, polymethacrylic acid (PMA, citric acid, and sodium bicarbonate. Tablets with 5% effervescent base had longer lag time than 10%. The type of polymer had no significant effect on the floating lag time. All tablets floated atop the medium for 23-24 hr. Increasing carbopolP934 caused higher bioadhesion than chitosan (p < 0.05. All formulations showed a Higuchi, non-Fickian release mechanism. Tablets with 10% effervescent base, 80% CH/20% HPMC, or 80% CP/20% PMA seemed desirable.

Offshore Vendors’ Software Development Team Configurations

DEFF Research Database (Denmark)

Chakraborty, Suranjan; Sarker, Saonee; Rai, Sudhanshu

2012-01-01

This research uses configuration theory and data collected from a major IT vendor organization to examine primary configurations of distributed teams in a global off-shoring context. The study indicates that off-shoring vendor organizations typically deploy three different types of configurations...

Using decommissioned offshore oil/gas platforms for nuclear/RO desalination: the ONDP (Offshore Nuclear Desalination Platform)

International Nuclear Information System (INIS)

Nagar, Ankesh

2010-01-01

shore by cables alongside the pipeline as additional bounty. The nuclear submarines and ships have been sailing the oceans of the world with these reactors and have proven safe. The other non-conventional energy sources like windmills and wave energy generation have also been tried on oil platforms but the magnitude of energy generation and desalination is incomparable with nuclear energy. The KLT 40S reactors are compact easy to transport and ship, built with excellent safety mechanisms, efficient and are made with 'plug and play' philosophy. The use of non weapon grade uranium makes them ideal for installing them offshore with existing security. They have a proven safety record as well and are cost effective in long run. These 'to be decommissioned' oil platforms are also ideal for DEMWAX (Reverse Osmosis) plants which instead of floats can be anchored at the base of the platform where they meet the required gravity, current and pressure. The location of oil platforms minimizes biofouling and reduces power requirement. Brine plume is also taken care with the available wide ocean floor and strong currents. The challenge is to integrate ready oil platform infrastructure with proven safe nuclear technology and water-management measures, to put them to practice with modification in an Offshore Nuclear Desalination Platform (ONDP). (author)

46 CFR 15.520 - Mobile offshore drilling units.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in this...

Floating Solar Photovoltaics Gaining Ground | State, Local, and Tribal

Science.gov (United States)

flotovoltaics (a trademarked term) or floating solar, represent an emerging application in which PV panels are , including efficiency gains (due to water cooling the panels), reductions in unwanted algae growth, slower 994 panels floating on 130 foam-filled pontoons atop the winery's irrigation pond and an additional

EWeA Offshore 2013 - Side event: 'Offshore wind energy - Potentialities and industrial opportunities in France and in Germany. French-German cross perspectives

International Nuclear Information System (INIS)

Genachte, Anne-Benedicte; Kavafyan, Philippe; Wagner, Andreas; Bour, Gregoire

2013-01-01

At the EWEA Offshore 2013 exhibition, the French-German office for Renewable energies (OFAEnR) organised a side-conference on Offshore wind energy and its Potentialities and industrial opportunities in France and in Germany. In the framework of this French-German exchange of experience, about 50 participants exchanged views on the conditions for the development of a durable offshore wind energy industry both in France and in Germany. This document brings together the available presentations (slides) made during this event: 1 - Supporting industrial development of offshore wind in Europe (Anne-Benedicte Genachte); 2 - Offshore wind energy: the Bremerhaven experience. An asset for the deployment of a complete industrial field in France (Philippe Kavafyan); 3 - Status, Prospects and Challenges for Offshore Wind energy in Germany - incl. Legal Framework and Presentation of cost reduction study results (Andreas Wagner); 4 - Offshore grid connection in Germany - Challenges and recommendations (Gregoire Bour)

The EU Offshore Safety Directive and its potential effects. Opportunity or handicap?; Die EU Offshore Safety Directive und ihre moeglichen Auswirkungen. Chance oder Handicap?

Energy Technology Data Exchange (ETDEWEB)

Schwiederowski, Claudia [RWE Dea AG, Hamburg (Germany)

2014-07-01

The purpose of the EU Offshore Safety Directive, which took effect on 18 July 2013, is to define minimum requirements for the prevention of severe accidents in connection with offshore crude oil or natural gas activities of any kind and the containment of the follow-on effects of such accidents. This is without question a logical consequence of the offshore incidents seen around the globe over the past decades. An interesting question in this context is for whom the EU Offshore Safety Directive has become an opportunity and for whom a handicap. [German] Ziel der am 18. Juli 2013 in Kraft getretenen EU Offshore Safety Direktive ist die Festlegung von Mindestanforderungen fuer die Verhinderung schwerer Unfaelle bei Offshore-Erdoel- bzw. - Erdgasaktivitaeten und die Begrenzung etwaiger Unfallfolgen. Nach den weltweiten Offshore- Ereignissen der vergangenen Jahrzehnte ist dies ohne Zweifel eine logische Entwicklung. Nun stellt sich die Frage: Fuer wen entwickelt sich die EU Offshore Safety Directive zur Chance, fuer wen zum Handicap?.

The offshorization of economy: the present realities

Directory of Open Access Journals (Sweden)

Maslak Olga

2017-01-01

Full Text Available In this article the essence and main types of offshore zones have been studied. It has been analyzed the main reasons for cooperation with the tax havens, established that the main reason of the Ukrainian economy offshorization is not only the desire of economic entities to optimize taxes, but also the desire to protect their assets from the negative impact of the crisis phenomena in the national economy during 2010-2016. The foreign experience of the anti-offshore regulation has been researched. It has been defined that the general anti-offshore regulation vector should be based on the principles of financial transparency, active cooperation with the international community, an optimal combination of instruments that restrict the capital outflows and the effective instruments that stimulate the business development in the country. It has been also established that the mechanism of deoffshorization should be aimed not only at elimination of the territories with the preferential taxation, but also at receiving benefits from their use on the basis of the existing financial infrastructure of the leading world offshore centers. The experience of China in attracting additional foreign investments, gaining wider access to financial resources through the cooperation with an offshore financial centre has been researched.

Offshoring and financial markets

Directory of Open Access Journals (Sweden)

Gianfranco Battisti

2014-06-01

Full Text Available The paper analyses the nature and extent of the offshore world, a grey area that is playing a major role in present-day economy. The main institutions moulding this peculiar environment are discussed: preferential tax regimes, tax havens and offshore financial centers. Their role in the globalised world is outlined after a scrutiny of the specialized literature, reports by non-governmental bodies and companies’ advertisings. Finally, we present a tentative reconstruction of its geographical organization, inclusive of cartographic representations of the main international networks.

Multi-span Suspension Bridge with Floating Towers

OpenAIRE

Brunstad, Orjan

2013-01-01

The Norwegian Public Roads Administration (NPRA) is currently conducting a feasible study of crossing 8 fjords on the west coast of Norway. The most challenging crossing is the 3700 m wide Sognefjord. Three main concepts are under development, and one of the concepts of this crossing is a three span suspension bridge on floating towers. The floating foundation suggested is a multi-column pontoon with mooring lines to seabed. The object of this thesis was to study this bridge concept with resp...

31 CFR 587.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 587.406 Section 587.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... MONTENEGRO) MILOSEVIC SANCTIONS REGULATIONS Interpretations § 587.406 Offshore transactions. The prohibitions...

Project alliancing in the offshore industry

NARCIS (Netherlands)

Halman, Johannes I.M.; Braks, B.F.M.

In this paper the shift towards new types of project organisation within the Offshore Industry is explained and discussed. Special focus is given to the organisational concept of Project Alliancing. The principles, structure and culture of a Project Alliance as applied within the Offshore Industry

Current-Sensitive Path Planning for an Underactuated Free-Floating Ocean Sensorweb

Science.gov (United States)

Dahl, Kristen P.; Thompson, David R.; McLaren, David; Chao, Yi; Chien, Steve

2011-01-01

This work investigates multi-agent path planning in strong, dynamic currents using thousands of highly under-actuated vehicles. We address the specific task of path planning for a global network of ocean-observing floats. These submersibles are typified by the Argo global network consisting of over 3000 sensor platforms. They can control their buoyancy to float at depth for data collection or rise to the surface for satellite communications. Currently, floats drift at a constant depth regardless of the local currents. However, accurate current forecasts have become available which present the possibility of intentionally controlling floats' motion by dynamically commanding them to linger at different depths. This project explores the use of these current predictions to direct float networks to some desired final formation or position. It presents multiple algorithms for such path optimization and demonstrates their advantage over the standard approach of constant-depth drifting.

Screening Criteria and Considerations of Offshore Enhanced Oil Recovery

Directory of Open Access Journals (Sweden)

Pan-Sang Kang

2016-01-01

Full Text Available The application of enhanced oil recovery (EOR in offshore oil fields has received significant attention due to the potentially enormous amount of recoverable oil. However, EOR application offshore is in its very early stage due to conditions that are more complex than onshore oil fields, owing to the unique parameters present offshore. Therefore, successful EOR applications in offshore oil fields require different screening criteria than those for conventional onshore applications. A comprehensive database for onshore applications of EOR processes together with a limited offshore EOR application database are analyzed in this paper, and the important parameters for successful offshore application are incorporated into the new EOR screening criteria. In this paper, screening criteria to determine acceptable EOR processes for offshore fields, including hydrocarbon gas miscible, CO2 miscible, and polymer processes, are presented. Suggested screening criteria for these EOR processes comprise quantitative boundaries and qualitative considerations. Quantitative screening criteria are predominantly based on quantifiable data, such as oil and reservoir properties. Qualitative screening considerations mainly focus on the operational issues present offshore, including platform space constraints, limited disposal options, injectant availability, and flow assurance matters (including hydrate formation and difficulties in emulsion separation.

Design, Analysis, Hybrid Testing and Orientation Control of a Floating Platform with Counter-Rotating Vertical-Axis Wind Turbines

Science.gov (United States)

Kanner, Samuel Adam Chinman

The design and operation of two counter-rotating vertical-axis wind turbines on a floating, semi-submersible platform is studied. The technology, called the Multiple Integrated and Synchronized Turbines (MIST) platform has the potential to reduce the cost of offshore wind energy per unit of installed capacity. Attached to the platform are closely-spaced, counter-rotating turbines, which can achieve a higher power density per planform area because of synergistic interaction effects. The purpose of the research is to control the orientation of the platform and rotational speeds of the turbines by modifying the energy absorbed by each of the generators of the turbines. To analyze the various aspects of the platform and wind turbines, the analysis is drawn from the fields of hydrodynamics, electromagnetics, aerodynamics and control theory. To study the hydrodynamics of the floating platform in incident monochromatic waves, potential theory is utilized, taking into account the slow-drift yaw motion of the platform. Steady, second-order moments that are spatially dependent (i.e., dependent on the platform's yaw orientation relative to the incident waves) are given special attention since there are no natural restoring yaw moment. The aerodynamics of the counter-rotating turbines are studied in collaboration with researchers at the UC Berkeley Mathematics Department using a high-order, implicit, large-eddy simulation. An element flipping technique is utilized to extend the method to a domain with counter-rotating turbines and the effects from the closely-spaced turbines is compared with existing experimental data. Hybrid testing techniques on a model platform are utilized to prove the controllability of the platform in lieu of a wind-wave tank. A 1:82 model-scale floating platform is fabricated and tested at the UC Berkeley Physical-Model Testing Facility. The vertical-axis wind turbines are simulated by spinning, controllable actuators that can be updated in real-time of

Energy Usage of Residents on Offshore Islands in Taiwan

Directory of Open Access Journals (Sweden)

Szu-Cheng Lu

2015-05-01

Full Text Available A field study was conducted through interviews on offshore islands in Taiwan to investigate the energy usage of local residents. A comparison of household appliance usage in mainland Taiwan with that on the offshore islands revealed that, overall, the most commonly used household appliances are steam cookers/rice cookers, water dispensers, and washing machines. For other household appliances, Levels 2 and 3 offshore isles have lower use penetration rates compared with those in mainland Taiwan and on Level 1 offshore isles, particularly for the use of computers. By contrast, the use penetration rate for chest freezers on Levels 2 and 3 offshore isles is high, and each household has one or more freezers on average. This appliance is not a commonly observed household product in mainland Taiwan or on Level 1 offshore isles. Furthermore, because of the government policy, every household on parts of Level 2 offshore isles and on all Level 3 offshore isles has a fixed monthly charge of electricity. The transportation of liquefied petroleum gas is also inconvenient, and the gas price is slightly higher, leading to the tendency of residents to consume excessive amounts of electrical energy, which does not correspond with the aim of the government to conserve energy and reduce carbon emissions; thus, the relevant authorities’ review and improvement on energy consumption on Levels 2 and 3 offshore isles are required.

Extended onshore control of a floating wind turbine with wave disturbance reduction

DEFF Research Database (Denmark)

Christiansen, S.; Knudsen, T.; Bak, Thomas

2014-01-01

Reaching for higher wind resources floating wind turbines are being investigated. Wave induced loads significantly increase for floating wind turbines, and applying conventional onshore control strategies to floating wind turbines has been shown to impose negative damped oscillations in fore......-aft due to the low natural frequency of the floating structure. We suggest a control loop extension of the onshore controller which stabilizes the system and reduces the wave disturbance. The result is improved performance in power fluctuations, blade pitch activity, and platform oscillations...

Offshore Aquaculture: I Know It When I See It

Directory of Open Access Journals (Sweden)

Halley E. Froehlich

2017-05-01

Full Text Available Offshore aquaculture is increasingly viewed as a mechanism to meet growing protein demand for seafood, while minimizing adverse consequences on the environment and other uses in the oceans. However, despite growing interest in offshore aquaculture, there appears to be no consensus as to what measures commonly define an offshore site or how effects of offshore aquaculture—relative to more nearshore practices—are assessed. This lack of agreement on what constitutes offshore aquaculture has the potential to convolute communication, create uncertainty in regulatory processes, and impede understanding of the ecological implications of offshore farming. To begin addressing these issues, we reviewed and analyzed biologically-focused primary and gray literature (Ntotal = 70 that categorize and quantify characteristics of offshore aquaculture from around the world. We found that many “offshore” descriptions are relatively close to shore (<3 nm and significantly shallower (minimum depth ≤30 m than may be assumed. We also uncovered an overall lack of consistent reporting of even the most common location-focused metrics (distance from shore, depth, current, a dearth of impact related studies (n = 17, and narrow scope of the studies themselves (i.e., 82% nutrient pollution. Of the finite subset of articles that investigated negative ecological impacts of offshore aquaculture, we found the probability of any measurable impact from an offshore farm appears to significantly decrease with distance from the farm (probability of measurable response at 90 m ± SE = 0.01 ± 0.03. Such general, but informative points of reference could be more robustly quantified with better systematic and standardized reporting of physical farm characteristics and a broader scope of ecological investigation into the effects of marine aquaculture. With offshore aquaculture still in its infancy, consistent metrics are needed for a comparable framework to guide sustainable

Canadian East Coast offshore petroleum industry safe lifting practices respecting offshore pedestal cranes, offshore containers, loose gear, other lifting devices, and operational best practices : standard practices

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-11-15

This document was developed by a working group with representatives from the petroleum industry, the Offshore Petroleum Boards and Certifying Authorities. It outlines industry best practices for operators responsible for the management, planning and execution of offshore lifting operations. Its purpose is to assist in the interpretation of applicable legislation and standards. Considered within the practice are safe design requirements, manufacture, certification, testing, maintenance and inspection requirements for pedestal cranes, offshore containers, loose gear and lifting devices. Operational best practices for lifting operations are also included along with a section that identifies additional requirements for personnel lifting operations, including personnel transfers by crane and man-riding operations. 82 refs., 2 tabs., 4 figs., 3 appendices.

31 CFR 544.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 544.406 Section 544.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... SANCTIONS REGULATIONS Interpretations § 544.406 Offshore transactions. The prohibitions in § 544.201 on...

31 CFR 593.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 593.406 Section 593.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... SANCTIONS REGULATIONS Interpretations § 593.406 Offshore transactions. The prohibitions in § 593.201 on...

31 CFR 541.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 541.406 Section 541.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... § 541.406 Offshore transactions. The prohibitions in § 541.201 on transactions involving blocked...

31 CFR 537.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 537.406 Section 537.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... § 537.406 Offshore transactions. The prohibitions in § 537.201 on transactions involving blocked...

31 CFR 542.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... § 542.406 Offshore transactions. The prohibitions in § 542.201 on transactions involving blocked...

Viewing engineering offshoring in a network perspective

DEFF Research Database (Denmark)

Hansen, Zaza Nadja Lee; Zhang, Yufeng; Ahmed-Kristensen, Saeema

2013-01-01

of how to effectively manage engineering offshoring activities in a context of global engineering networks. The main research question, therefore, is: “Can offshoring of engineering tasks be explained and managed using the concept of Global Engineering Networks (GEN)?” Effective approaches to handling...... of large multinational corporations in Denmark were carried out. Data gathering was mainly documentary studies and interviews. The main data analysis approaches were coding (Strauss and Corbin) and pattern-matching (Yin). The dataset was analysed using the GEN framework suggested by Zhang et al. and Zhang...... by extending the GEN framework to address complications within engineering offshoring. This strengthens both academic fields, and will be able to help engineering managers to develop appropriate engineering network configurations for offshore engineering operations....

Managing Hidden Costs of Offshoring

DEFF Research Database (Denmark)

Larsen, Marcus M.; Pedersen, Torben

2014-01-01

This chapter investigates the concept of the ‘hidden costs’ of offshoring, i.e. unexpected offshoring costs exceeding the initially expected costs. Due to the highly undefined nature of these costs, we position our analysis towards the strategic responses of firms’ realisation of hidden costs....... In this regard, we argue that a major response to the hidden costs of offshoring is the identification and utilisation of strategic mechanisms in the organisational design to eventually achieving system integration in a globally dispersed and disaggregated organisation. This is heavily moderated by a learning......-by-doing process, where hidden costs motivate firms and their employees to search for new and better knowledge on how to successfully manage the organisation. We illustrate this thesis based on the case of the LEGO Group....

Methodology of life cycle cost with risk expenditure for offshore process at conceptual design stage

International Nuclear Information System (INIS)

Nam, Kiil; Chang, Daejun; Chang, Kwangpil; Rhee, Taejin; Lee, In-Beum

2011-01-01

This study proposed a new LCC (life cycle cost) methodology with the risk expenditure taken into account for comparative evaluation of offshore process options at their conceptual design stage. The risk expenditure consisted of the failure risk expenditure and the accident risk expenditure. The former accounted for the production loss and the maintenance expense due to equipment failures while the latter reflected the asset damage and the fatality worth caused by disastrous accidents such as fire and explosion. It was demonstrated that the new LCC methodology was capable of playing the role of a process selection basis in choosing the best of the liquefaction process options including the power generation systems for a floating LNG (Liquefied natural gas) production facility. Without the risk expenditure, a simple economic comparison apparently favored the mixed refrigerant cycle which had the better efficiency. The new methodology with the risk expenditure, however, indicated that the nitrogen expansion cycle driven by steam turbines should be the optimum choice, mainly due to its better availability and safety. -- Highlights: → The study presented the methodology of the LCC with the risk expenditure for the conceptual design of offshore processes. → The proposed methodology demonstrated the applicability of the liquefaction unit with the power generation system of LNG FPSO. → Without the risk expenditure, a simple economic comparison apparently favored the mixed refrigerant cycle which had the better efficiency. → The new methodology indicated that the nitrogen expansion cycle driven by steam turbines is the optimum choice due to its better availability and safety.

Offshore Wind Turbine Design

DEFF Research Database (Denmark)

Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo

2006-01-01

Current offshore wind turbine design methods have matured to a 1st generation state, manifested in the draft of a possible standard, IEC 61400-3 (2005). It is now time to investigate the possibilities of improving existing methods. To do so in an efficient manner a clear identification of the most...... important uncertainty drivers specific for offshore wind turbine design loads is required. Describing the initial efforts in a Danish research project, the paper points to focal points for research and development. These are mainly: soil-structure interaction, improved modelling of wave loads from deep...

Floating Oil-Spill Containment Device

Science.gov (United States)

Jones, Jack A.

2012-01-01

Previous oil containment booms have an open top that allows natural gas to escape, and have significant oil leakage due to wave action. Also, a subsea pyramid oil trap exists, but cannot move relative to moving oil plumes from deepsea oil leaks. The solution is to have large, moveable oil traps. One version floats on the sea surface and has a flexible tarp cover and a lower weighted skirt to completely entrap the floating oil and natural gas. The device must have at least three sides with boats pulling at each apex, and sonar or other system to track the slowly moving oil plume, so that the boats can properly locate the booms. The oil trap device must also have a means for removal of the oil and the natural gas. A second design version has a flexible pyramid cover that is attached by lines to ballast on the ocean floor. This is similar to fixed, metal pyramid oil capture devices in the Santa Barbara Channel off the coast of California. The ballast lines for the improved design, however, would have winches that can move the pyramid to always be located above the oil and gas plume. A third design is a combination of the first two. It uses a submerged pyramid to trap oil, but has no anchor and uses boats to locate the trap. It has ballast weights located along the bottom of the tarp and/or at the corners of the trap. The improved floating oil-spill containment device has a large floating boom and weighted skirt surrounding the oil and gas entrapment area. The device is triangular (or more than three sides) and has a flexible tarp cover with a raised gas vent area. Boats pull on the apex of the triangles to maintain tension and to allow the device to move to optimum locations to trap oil and gas. The gas is retrieved from a higher buoyant part of the tarp, and oil is retrieved from the floating oil layer contained in the device. These devices can be operated in relatively severe weather, since waves will break over the devices without causing oil leaking. Also, natural

Argo Float Data from the APDRC DAPPER Server, 1995-present

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The floats are designed to drift at a fixed pressure (usually 1000 dbar) for 10 days. After this period, the floats move to a profiling pressure (usually between...

FLOAT2 WP4: Development of Materials

DEFF Research Database (Denmark)

Esteves, Luis Pedro; Aarup, Bendt

This report refers to complementary material testing to support the design and production of UHPC floaters for installation in the Wave Star Machine under FLOAT2 project. The main objective of WP4 is the characterization of mechanical properties of fiber-reinforced UHPC.......This report refers to complementary material testing to support the design and production of UHPC floaters for installation in the Wave Star Machine under FLOAT2 project. The main objective of WP4 is the characterization of mechanical properties of fiber-reinforced UHPC....

Effects of Electrolyte on Floating Water Bridge

OpenAIRE

Hideo Nishiumi; Fumitaka Honda

2009-01-01

Fuchs found phenomena that when high voltage is applied to deionized water filled in two contacted beakers, a floating water bridge forms spontaneously. In this paper, we examined flow direction of water bridge and what effects the addition of electrolytes such as NaCl, NaOH, and N H 4 C l to the floating water bridge would give. We found that ionization degree reduced the length of water bridge though insoluble electrolyte A l 2 O 3 had no effect on the length of water bridge.

Efficient promotion of electricity production from offshore wind; Effiziente Foerderung der Stromerzeugung aus Offshore-Wind

Energy Technology Data Exchange (ETDEWEB)

Panzer, Christian; Auer, Hans; Lettner, Georg [Technische Univ. Wien (Austria). Energy Economics Group (EEG)

2014-03-15

Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

Offshore wind potential evaluation and remote sensing imagery; Evaluation du potentiel eolien offshore et imagerie satellitale

Energy Technology Data Exchange (ETDEWEB)

Fichaux, N.

2003-12-15

Offshore wind energy may help to contribute to the respect of the Kyoto objectives by Europe. It is a key issue to struggle against global change. To sit the future offshore wind parks, it is necessary to accurately evaluate the spatial repartition of the wind potential. We demonstrate that the offshore wind potential shall be represented by maps of wind statistics. As remote sensing is a tool for measuring space physical phenomena, we evaluate its potentialities for mapping wind statistics. Space-borne scatterometers enables the obtention of wind statistics, but far from our areas of interest and at low spatial resolution. Synthetic Aperture Radar (SAR) enables the computation of high resolution wind maps over our areas of interest, but are unsuitable to compute wind statistics. We define the mathematical framework of a statistical method. That method enables to take advantage of both scatterometer and SAR to compute maps of wind statistics at high spatial resolution over the areas of interest. It enables remote sensing to be used operationally to map the offshore wind potential. (author)

31 CFR 543.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 543.406 Section 543.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Interpretations § 543.406 Offshore transactions. The prohibitions in § 543.201 on transactions or dealings...

31 CFR 597.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 597.406 Section 597.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... REGULATIONS Interpretations § 597.406 Offshore transactions. The prohibitions contained in § 597.201 apply to...

31 CFR 547.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 547.406 Section 547.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... REGULATIONS Interpretations § 547.406 Offshore transactions. The prohibitions in § 547.201 on transactions or...

31 CFR 548.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... § 548.406 Offshore transactions. The prohibitions in § 548.201 on transactions or dealings involving...

31 CFR 546.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 546.406 Section 546.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... § 546.406 Offshore transactions. The prohibitions in § 546.201 on transactions or dealings involving...

31 CFR 588.406 - Offshore transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 588.406 Section 588.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Interpretations § 588.406 Offshore transactions. The prohibitions in § 588.201 on transactions involving blocked...

The study to estimate the floating population in Seoul, Korea.

Science.gov (United States)

Lee, Geon Woo; Lee, Yong Jin; Kim, Youngeun; Hong, Seung-Han; Kim, Soohwaun; Kim, Jeong Soo; Lee, Jong Tae; Shin, Dong Chun; Lim, Youngwook

2017-01-01

Traffic-related pollutants have been reported to increase the morbidity of respiratory diseases. In order to apply management policies related to motor vehicles, studies of the floating population living in cities are important. The rate of metro rail transit system use by passengers residing in Seoul is about 54% of total public transportation use. Through the rate of metro use, the people-flow ratios in each administrative area were calculated. By applying a people-flow ratio based on the official census count, the floating population in 25 regions was calculated. The reduced level of deaths among the floating population in 14 regions having the roadside monitoring station was calculated as assuming a 20% reduction of mobile emission based on the policy. The hourly floating population size was calculated by applying the hourly population ratio to the regional population size as specified in the official census count. The number of people moving from 5 a.m. to next day 1 a.m. could not be precisely calculated when the population size was applied, but no issue was observed that would trigger a sizable shift in the rate of population change. The three patterns of increase, decrease, and no change of population in work hours were analyzed. When the concentration of particulate matter less than 10 μm in aerodynamic diameter was reduced by 20%, the number of excess deaths varied according to the difference of the floating population. The effective establishment of directions to manage the pollutants in cities should be carried out by considering the floating population. Although the number of people using the metro system is only an estimate, this disadvantage was supplemented by calculating inflow and outflow ratio of metro users per time in the total floating population in each region. Especially, 54% of metro usage in public transport causes high reliability in application.

The study to estimate the floating population in Seoul, Korea

Directory of Open Access Journals (Sweden)

Geon Woo Lee

2017-05-01

Full Text Available Traffic-related pollutants have been reported to increase the morbidity of respiratory diseases. In order to apply management policies related to motor vehicles, studies of the floating population living in cities are important. The rate of metro rail transit system use by passengers residing in Seoul is about 54% of total public transportation use. Through the rate of metro use, the people-flow ratios in each administrative area were calculated. By applying a people-flow ratio based on the official census count, the floating population in 25 regions was calculated. The reduced level of deaths among the floating population in 14 regions having the roadside monitoring station was calculated as assuming a 20% reduction of mobile emission based on the policy. The hourly floating population size was calculated by applying the hourly population ratio to the regional population size as specified in the official census count. The number of people moving from 5 a.m. to next day 1 a.m. could not be precisely calculated when the population size was applied, but no issue was observed that would trigger a sizable shift in the rate of population change. The three patterns of increase, decrease, and no change of population in work hours were analyzed. When the concentration of particulate matter less than 10 μm in aerodynamic diameter was reduced by 20%, the number of excess deaths varied according to the difference of the floating population. The effective establishment of directions to manage the pollutants in cities should be carried out by considering the floating population. Although the number of people using the metro system is only an estimate, this disadvantage was supplemented by calculating inflow and outflow ratio of metro users per time in the total floating population in each region. Especially, 54% of metro usage in public transport causes high reliability in application.

Offshore Outlook: the European Side Perspectives offshore : le point de vue européen

Directory of Open Access Journals (Sweden)

Delacour J.

2006-11-01

Full Text Available The offshore hydrocarbon potential of Europe was fully revealed during the 1970s by various major discoveries which, after the first oil shock in 1973 and in the light of the high energy consumption in this zone, were a major asset in the new equilibria that would be found between producing and consuming countries. The offshore potential of Europe is concentrated in two zones: the North Sea and the Mediterranean. The North Sea, with the particularly harsh operating conditions, has quickly given rise to what can today be qualified as a new engineering state-of-the-art. At the same time, developments in the Mediterranean have brought a demonstration of entirely original and profitable petroleum achievements. For the future and despite current economic uncertainties, the outlook for European offshore development remain particularly attractive, obviously with regard to oil, but also, and more and more so, from the standpoint of natural gas. Le potentiel offshore en hydrocarbures de l'Europe a été pleinement mis en évidence au cours des années 70 par un certain nombre de grandes découvertes qui constituaient, après le premier choc pétrolier de 1973, compte tenu des fortes consommations d'énergie dans cette zone, un atout majeur dans les nouveaux équilibres qui s'instauraient entre pays producteurs et pays consommateurs. Le potentiel offshore de l'Europe se concentre sur deux zones : la mer du Nord et la Méditerranée. La mer du Nord, avec des conditions d'exploitation particulièrement sévères, a donné rapidement naissance à ce que l'on peut, aujourd'hui, qualifier de nouvel art de l'ingénieur, tandis que les développements en Méditerranée apportaient la démonstration de réalisations pétrolières tout à fait originales et profitables. Pour le futur, et malgré les incertitudes économiques actuelles, les perspectives de développement de l'offshore européen restent particulièrement attractives, au niveau du pétrole �

Baltic 2 offshore wind farm. Challenges and solutions during design and erection of a 288 MW offshore wind power plant; Baltic 2 Offshore Windpark. Herausforderungen und Loesungen waehrend der Design- und Errichtungsphase eines 288 MW Offshore-Windkraftwerks

Energy Technology Data Exchange (ETDEWEB)

Stamatelopoulos, Georg-Nikolaus; Kansy, Stefan [EnBW Energie Baden-Wuerttemberg AG, Stuttgart (Germany); Hannibal, John Michael [Siemens AG, Hamburg (Germany). Wind Power and Renewables Div.; Frettloehr, Bjoern [EnBW Energie Baden-Wuerttemberg AG, Hamburg (Germany). Wind und Maritime Technik

2015-05-01

Offshore wind offers a great potential for reliable power supply with markedly less future costs. However, offshore also means special requirements related to transport and installation at sea. Even if these requirements alone are very stringent, they are not the only ones that apply. Meeting these challenges requires project organisation comparable to other major projects.

14 CFR 136.11 - Helicopter floats for over water.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Helicopter floats for over water. 136.11... TOURS AND NATIONAL PARKS AIR TOUR MANAGEMENT National Air Tour Safety Standards § 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must...

A Method for Modeling of Floating Vertical Axis Wind Turbine

DEFF Research Database (Denmark)

Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir

2013-01-01

It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper....... In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine....... This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor...

The Organizational Design of Offshoring

DEFF Research Database (Denmark)

Ørberg Jensen, Peter D.; Larsen, Marcus M.; Pedersen, Torben

2013-01-01

Offshoring can be defined as the relocation of organizational tasks and services to foreign locations. At the same time as the scale and scope of offshoring have reached unprecedented levels in recent years, firms have increasingly been exposed to the challenges relating to managing an organizati...... implies an organizational reconfiguration consisting of three stages: disintegration, relocation and reintegration. We discuss the implications of this perspective and outline a research agenda....

Denmark - supplier of competitive offshore wind solutions. Megavind's strategy for offshore wind research, development and demonstration

Energy Technology Data Exchange (ETDEWEB)

2010-12-15

In May 2006, the Danish Government presented a report on promoting environmentally effective technology and established a number of innovative partnerships. The partnerships intend to strengthen public-private cooperation between the state, industry, universities and venture capital to accelerate innovation for a number of green technologies. The partnership for wind energy is called Megavind. Megavind's strategy for offshore wind describes the offshore challenges and suggests research, development and demonstration (RD and D) priorities to enable offshore wind power become to competitive with other energy technologies. The strategy lists key recommendations as well as key thematic priorities and for each of these a number of RD and D priorities. Under each thematic priority references are made to the European Strategic Energy Technology plan (SET-plan), which prioritises offshore wind RD and D in Europe. (LN)

The floating water bridge

International Nuclear Information System (INIS)

Fuchs, Elmar C; Woisetschlaeger, Jakob; Gatterer, Karl; Maier, Eugen; Pecnik, Rene; Holler, Gert; Eisenkoelbl, Helmut

2007-01-01

When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

Offshoring in the Semiconductor Industry: Historical Perspectives

OpenAIRE

Brown, Clair; Linden, Greg

2005-01-01

Semiconductor design is a frequently-cited example of the new wave of offshoring and foreign-outsourcing of service sector jobs. It is certainly a concern to U.S. design engineers themselves. In addition to the current wave of white-collar outsourcing, the industry also has a rich experience with offshoring of manufacturing activity. Semiconductor companies were among the first to invest in offshore facilities to manufacture goods for imports back to the U.S. A brief review of these earlie...

The offshorization of economy: the present realities

OpenAIRE

Maslak Olga; Grishko Natalya; Hlazunova Olha; Vorobiova Kateryna

2017-01-01

In this article the essence and main types of offshore zones have been studied. It has been analyzed the main reasons for cooperation with the tax havens, established that the main reason of the Ukrainian economy offshorization is not only the desire of economic entities to optimize taxes, but also the desire to protect their assets from the negative impact of the crisis phenomena in the national economy during 2010-2016. The foreign experience of the anti-offshore regulation has been researc...

Float level indicator

International Nuclear Information System (INIS)

Grishchuk, M.Kh.; Laptev, A.G.; Pashkov, V.A.

1980-01-01

Specially developed level indicator is suggested with differential to-transformer converter of the float motion, operating in line with a movable electronic block, intended for indicating the level of the dissociating nitrogen tetroxide liquid phase. On the basis of the indicator elements the device is realized to measure the time of calibrated volume fillino. in by liquid nitrogen tetroxide in steady state operation of the experimental bench-marks [ru

Switching overvoltages in offshore wind power grids

DEFF Research Database (Denmark)

Arana Aristi, Ivan

and cables are presented. In Chapter 4 results from time domain measurements and simulations of switching operations in offshore wind power grids are described. Specifically, switching operations on a single wind turbine, the collection grid, the export system and the external grid measured in several real...... offshore wind farms are shown together with simulation results. Switching operations in offshore wind power grids can be simulated with different electromagnetic transient programs. Different programs were used in the project and compared results are included in Chapter 4. Also in Chapter 4 different......Switching transients in wind turbines, the collection grid, the export system and the external grid in offshore wind farms, during normal or abnormal operation, are the most important phenomena when conducting insulation coordination studies. However, the recommended models and methods from...

Ranitidine Loaded Biopolymer Floats: Designing, Characterization, and Evaluation

Directory of Open Access Journals (Sweden)

Abdul Karim

2017-01-01

Full Text Available The float formulation is a strategy to improve the bioavailability of drugs by gastroretentive drug delivery system (GRDDS. A drug delivery model based on swellable and reswellable low density biopolymers has been designed to evaluate its drug release profile using ranitidine (RNT as a model drug and formulations have been prepared utilizing 32 factorial designs. The drug release (DR data has been subjected to various kinetic models to investigate the DR mechanism. A reduction in rate has been observed by expanding the amounts of PSG and LSG parts, while an expansion has been noted by increasing the concentration of tragacanth (TG and citric acid (CA with an increment in floating time. The stearic acid (SA has been used to decrease the lag time because a decrease in density of system was observed. The kinetic analysis showed that the optimized formulation (S4F3 followed zero-order kinetics and power law was found to be best fitted due to its minimum lag time and maximum floating ability. The resemblance of observed and predicted values indicated the validity of derived equations for evaluating the effect of independent variables while kinetic study demonstrated that the applied models are feasible for evaluating and developing float for RNT.

Damage to offshore infrastructure in the Gulf of Mexico by hurricanes Katrina and Rita

Science.gov (United States)

Cruz, A. M.; Krausmann, E.

2009-04-01

and occurred on both fixed and floating platforms. The total number of pipelines damaged by Hurricanes Katrina and Rita as of May 1, 2006, was 457. Pipeline damage was mostly caused by damage or failure of the host platform or its development and production piping, the impact of dragging and displaced objects, and pipeline interaction at a crossing. Damage to pipelines was a major contributing factor in delaying start up of offshore oil and gas production. During our analysis of the NRC database we identified 611 reported hazardous-materials releases directly attributed to offshore platforms and pipelines affected by the two hurricanes. There were twice as many releases during Hurricane Katrina than during Rita; 80% or more of the releases reported in the NRC database occurred from platforms. Our analysis suggests that the majority of releases were petroleum products, such as crude oil and condensate, followed by natural gas. In both Katrina and Rita, releases were more likely in the front, right quadrant of the storm. Storm-surge values were highest closer to the coastline. This may help explain the higher number of releases in shallow waters. The higher number of hazardous-materials releases from platforms during Katrina may partly be attributed to the higher wind speeds for this storm as it approached land.

Floating cultivation of marine cyanobacteria using coal fly ash.

Science.gov (United States)

Matsumoto, M; Yoshida, E; Takeyama, H; Matsunaga, T

2000-01-01

The aim of this study was to develop improved methodologies for bulk culturing of biotechnologically useful marine cyanobacteria in the open ocean. We have investigated the viability of using coal fly ash (CFA) blocks as the support medium in a novel floating culture system for marine micro-algae. The marine cyanobacterium Synechococcus sp. NKBG 040607 was found to adhere to floating CFA blocks in liquid culture medium. Maximum density of attached cells of 2.0 x 10(8) cells/cm2 was achieved using seawater. The marine cyanobacterium Synechococcus sp. NKBG 042902 weakly adhered to floating CFA blocks in BG-11 medium. Increasing the concentration of calcium ion in the culture medium enhanced adherence to CFA blocks.

Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles

DEFF Research Database (Denmark)

Sørensen, Søren Peder Hyldal

Offshore wind power is a domestic, sustainable and largely untapped energy resource. Today, the modern offshore wind turbine offers competitive production prices compared to other sources of renewable energy. Therefore, it is a key technology in breaking the dependence on fossil fuels...... and in achieving the energy and climate goals of the future. For offshore wind turbines, the costs of foundation typically constitute 20-30% of the total costs. Hence, improved methods for the design of foundations for offshore wind turbines can increase the competitiveness of offshore wind energy significantly....... The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. Therefore, this PhD thesis concerns the soil-pile interaction for non-slender, large-diameter offshore piles. A combination of numerical and physical modelling has been...

Visual disamenities from off-shore wind farms in Denmark

DEFF Research Database (Denmark)

Ladenburg, Jacob; Dubgaard, Alex; Tranberg, Jesper

2006-01-01

Expansion of the off-shore wind power plays a significant role in the energy policies of many EU countries. However, off-shore wind farms create visual disamenities. These disamenities can be reduced by locating wind farms at larger distances from the coast – and accepting higher costs per k......Wh produced. Base on the choices among alternative wind farm outlays, the preferences for reducing visual disamenities of off-shore wind farms were elicited using the Choice Experiment Method. The results show a clear picture; the respondents in three independent samples are willing to pay for mowing future...... off-shore wind farms away from the shore to reduce the wind farms visibility. However, the results also denote that the preferences vary with regards to the experiences with visual disamenities of off-shore wind farms. The respondents Horns Revs sample, where the off-shore wind farm is located...

Response estimation for a floating bridge using acceleration output only

NARCIS (Netherlands)

Petersen, Øyvind Wiig; Øiseth, Ole; Nord, Torodd Skjerve; Lourens, E.; Sas, P.; Moens, D.; van de Walle, A.

2016-01-01

The Norwegian Public Roads Administration is reviewing the possibility of using floating bridges as fjord crossings. The dynamic behaviour of very long floating bridges with novel designs are prone to uncertainties. Studying the dynamic behaviour of existing bridges is valuable for understanding

Biogeochemical sensor performance in the SOCCOM profiling float array

Science.gov (United States)

Johnson, Kenneth S.; Plant, Joshua N.; Coletti, Luke J.; Jannasch, Hans W.; Sakamoto, Carole M.; Riser, Stephen C.; Swift, Dana D.; Williams, Nancy L.; Boss, Emmanuel; Haëntjens, Nils; Talley, Lynne D.; Sarmiento, Jorge L.

2017-08-01

The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program has begun deploying a large array of biogeochemical sensors on profiling floats in the Southern Ocean. As of February 2016, 86 floats have been deployed. Here the focus is on 56 floats with quality-controlled and adjusted data that have been in the water at least 6 months. The floats carry oxygen, nitrate, pH, chlorophyll fluorescence, and optical backscatter sensors. The raw data generated by these sensors can suffer from inaccurate initial calibrations and from sensor drift over time. Procedures to correct the data are defined. The initial accuracy of the adjusted concentrations is assessed by comparing the corrected data to laboratory measurements made on samples collected by a hydrographic cast with a rosette sampler at the float deployment station. The long-term accuracy of the corrected data is compared to the GLODAPv2 data set whenever a float made a profile within 20 km of a GLODAPv2 station. Based on these assessments, the fleet average oxygen data are accurate to 1 ± 1%, nitrate to within 0.5 ± 0.5 µmol kg-1, and pH to 0.005 ± 0.007, where the error limit is 1 standard deviation of the fleet data. The bio-optical measurements of chlorophyll fluorescence and optical backscatter are used to estimate chlorophyll a and particulate organic carbon concentration. The particulate organic carbon concentrations inferred from optical backscatter appear accurate to with 35 mg C m-3 or 20%, whichever is larger. Factors affecting the accuracy of the estimated chlorophyll a concentrations are evaluated.Plain Language SummaryThe ocean science community must move toward greater use of autonomous platforms and sensors if we are to extend our knowledge of the effects of climate driven change within the ocean. Essential to this shift in observing strategies is an understanding of the performance that can be obtained from biogeochemical sensors on platforms deployed for years and the

Offshore Resource Assessment and Design Conditions: A Data Requirements and Gaps Analysis for Offshore Renewable Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Elliott, Dennis [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frame, Caitlin [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Gill, Carrie [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Hanson, Howard [Florida Atlantic Univ., Boca Raton, FL (United States); Moriarty, Patrick [National Renewable Energy Lab. (NREL), Golden, CO (United States); Powell, Mark [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Shaw, William J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wilczak, Jim [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Wynne, Jason [Energetics, Columbia, MD (United States)

2012-03-01

The offshore renewable energy industry requires accurate meteorological and oceanographic (“metocean”) data for evaluating the energy potential, economic viability, and engineering requirements of offshore renewable energy projects. It is generally recognized that currently available metocean data, instrumentation, and models are not adequate to meet all of the stakeholder needs on a national scale. Conducting wind and wave resource assessments and establishing load design conditions requires both interagency collaboration as well as valuable input from experts in industry and academia. Under the Department of Energy and Department of Interior Memorandum of Understanding, the Resource Assessment and Design Condition initiative supports collaborative national efforts by adding to core atmospheric and marine science knowledge relevant to offshore energy development. Such efforts include a more thorough understanding and data collection of key metocean phenomena such as wind velocity and shear; low-level jets; ocean, tidal, and current velocities; wave characteristics; geotechnical data relating to surface and subsurface characteristics; seasonal and diurnal variations; and the interaction among these conditions. Figure 1 presents a graphical representation of some metocean phenomena that can impact offshore energy systems. This document outlines the metocean observations currently available; those that are not available; and those that require additional temporal-spatial coverage, resolution, or processing for offshore energy in an effort to gather agreed-upon, needed observations.

A GLANCE AT OFFSHORE WIND TURBINE FOUNDATION STRUCTURES

Directory of Open Access Journals (Sweden)

Jianhua Zhang

2016-06-01

Full Text Available Energy poverty and climate change are crucial issues we face in our societies. Offshore wind energy has been a reliable solution to both of these problems - solving our growing energy problems while reducing CO2 emission. Innovative foundation design is one of the setbacks faced by this industry. Designing and constructing a cost effective offshore wind farm is greatly hampered by technical and infrastructural challenges, especially in foundation structures. This paper provides a detailed overview of issues related to this problem, with the aim of eliminating the frequent misunderstandings which can arise among engineers and investors working in the offshore wind energy sector. It begins by investigating the latest data and recommendations regarding the design and deployment of various kinds of offshore wind turbine (OWT foundations. It provides a framework which enables us to study the different OWT foundations, including prototypes and their limitations. Various structural failure modes are highlighted and corrosion measures are presented. Moreover, various removal methods of support structures are put forward. Finally, this paper presents the setbacks preventing the spread of offshore wind energy and the future works for offshore wind energy applications.

Floating Microparticulate Oral Diltiazem Hydrochloride Delivery ...

African Journals Online (AJOL)

Delivery System for Improved Delivery to Heart ... Conclusion: Microparticulate floating (gastroretentive) oral drug delivery system of diltiazem prepared ..... treatment of cardiac disease. ... hydrochloride-loaded mucoadhesive microspheres.

Offshore Supply Industry Dynamics

DEFF Research Database (Denmark)

Roslyng Olesen, Thomas

The value chains for offshore oil and gas and offshore wind are both basically driven by the demand for energy. This is heavily dependent on a number of factors including the price of various energy sources and the policy making of the states which influence legislation, indirect subsidies...... of services including includes legal advice, financing, insurance etc. The two value chains have a number of activities in common. Both include (1) a tender and concession phase where the energy company obtains the right to explore and produce energy from the authorities. (2) An exploration phase where...

The Offshore New European Wind Atlas

Science.gov (United States)

Karagali, I.; Hahmann, A. N.; Badger, M.; Hasager, C.; Mann, J.

2017-12-01

The New European Wind Atlas (NEWA) is a joint effort of research agencies from eight European countries, co-funded under the ERANET Plus Program. The project is structured around two areas of work: development of dynamical downscaling methodologies and measurement campaigns to validate these methodologies, leading to the creation and publication of a European wind atlas in electronic form. This atlas will contain an offshore component extending 100 km from the European coasts. To achieve this, mesoscale models along with various observational datasets are utilised. Scanning lidars located at the coastline were used to compare the coastal wind gradient reproduced by the meso-scale model. Currently, an experimental campaign is occurring in the Baltic Sea, with a lidar located in a commercial ship sailing from Germany to Lithuania, thus covering the entire span of the south Baltic basin. In addition, satellite wind retrievals from scatterometers and Synthetic Aperture Radar (SAR) instruments were used to generate mean wind field maps and validate offshore modelled wind fields and identify the optimal model set-up parameters.The aim of this study is to compare the initial outputs from the offshore wind atlas produced by the Weather & Research Forecasting (WRF) model, still in pre-operational phase, and the METOP-A/B Advanced Scatterometer (ASCAT) wind fields, reprocessed to stress equivalent winds at 10m. Different experiments were set-up to evaluate the model sensitivity for the various domains covered by the NEWA offshore atlas. ASCAT winds were utilised to assess the performance of the WRF offshore atlases. In addition, ASCAT winds were used to create an offshore atlas covering the years 2007 to 2016, capturing the signature of various spatial wind features, such as channelling and lee effects from complex coastal topographical elements.

Economic optimization of offshore wind farms

International Nuclear Information System (INIS)

Pauling, T.

1996-09-01

The study on the title subject continues the development of a cost model for offshore wind farms started at the Institute for Wind Energy (IW) in 1995, and applies it on different kinds of cost analyses. The model will be considered within the European research project 'Structural and Economic Optimization of Bottom-Mounted Offshore Wind Energy Converters' (Opti-OWECS, JOR3-CT95-0087) co-ordinated by the IW, where also the cost analyses and optimization will be extended. The conclusions of the investigations have already been presented at the European Union Wind Energy Conference '96 at Goeteborg, Sweden. In Chapter 1, a short overview of former offshore studies and projects is given, especially those dealing with cost analysis. Typical cost breakdowns of offshore and onshore wind farms are compared. Chapter 2 contains a brief description of the cost model in its present state. The recent improvements and extensions are documented in Chapter 3, and a validation by means of a recalculation of two former offshore studies is carried out in Chapter 4. In Chapter 5, four different offshore sites are compared with respect to the same farm size and an optimized farm design: Jade in the German part of the North Sea near Wilhelmshafen; Swansea Bay in the Bristol Channel at the British Atlantic Coast; Rostock at the German Baltic Coast, and IJmuiden in the Dutch part of the North Sea. In Chapter 6, a sensitivity study is carried out for a variety of site, design and economical parameters. The results of this project are summarized in Chapter 7, and an outlook is given in Chapter 8. The appendix contains among others a description of the SCOptiM2 code, where the model is implemented, as well as data obtained from the parameter studies and design optimizations. 30 figs., 8 tabs., 6 appendices, 40 refs

Offshore production flares: a PETROBRAS review

Energy Technology Data Exchange (ETDEWEB)

Pagot, Paulo R.; Burmann, Clovis P.; Araujo, Paulo Bento de; Motomura, Tsukasa [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2008-07-01

The purpose of the present work is to briefly present the offshore flare system technological evolution and the main design criteria for flare and its supporting structure. In order to perform the aimed task, this work was divided into two parts: the first part presents the technological evolution of the offshore production flares and the second one discusses the flare system designing criteria. The evolution of the technology associated to the offshore production flares is organized by the authors just dividing the history in four chronological phases. Each phase is defined by the predominant use of the, by the time, most up-to-date technological alternative and it will be described with the help of sketches, drawings, photographs, data and information about the platforms where such technologies were applied. The second part of the present work discusses the dimensional criteria, interesting aspects and flaws of the offshore flare systems in two different fields, which are: definition of the flare system capacity; and flow and thermal design of the flare system. (author)

Development opportunities for the UK offshore wind industry

International Nuclear Information System (INIS)

1999-01-01

This report summarises the results of a study investigating the UK's ability to compete for the construction of offshore wind farms. The European offshore wind farm market is examined, and the UK offshore construction equipment and wind farm construction methods are analysed, and recommendations for a purpose build or modified construction vessel are presented. The appendix gives UK construction companies addresses and contact names

Oil exploration and production offshore Sakhalin Island

Energy Technology Data Exchange (ETDEWEB)

Reed, I.C. [Sakhalin Energy Investment Company, Yuzhno-Sakhalinsk (Russian Federation)

2006-11-15

The offshore oil and gas exploration that is currently taking place on Sakhalin Island was discussed, with particular reference to the status of Sakhalin Energy and the challenges facing oil and exportation from the ice covered waters of Russia's Sea of Okhotsk. Sakhalin Energy, an incorporated joint venture of a consortium of companies, completed a feasibility study for oil production off the east coast of Sakhalin Island in December 1992. Sakhalin Energy has two fields, namely the Piltun Astokhskoye and Lunskoye fields. The Piltun Astokhskoye field is currently under production via the Molikpaq platform and the Lunskoye field and northern part of Piltun Astokhskoye field are currently being developed under the Phase 2 project. Since 1999, Sakhalin Energy has been producing oil from a caisson structure drilling rig which was fitted with ice protection shielding around the waterline in order to comply with Russian requirements. Production is via an undersea pipeline to a Single Anchor Leg Mooring (SALM) unit and then to a Floating Storage and Offloading unit (FSO). A brief outline of the structure was presented along with current ice management procedures and arrangements. In order to maximize the length of the production season, ice management is used to enable an early start and a late end to production. It was noted that great care is taken to ensure that the operations in ice are carried out with consideration of the environmentally sensitive area that is home to the endangered Western Gray Whale and Stellar Sea Eagle. 3 refs., 1 tab., 7 figs.

Collector floating potentials in a discharge plasma

International Nuclear Information System (INIS)

Cercek, M.; Gyergyek, T.

1999-01-01

We present the results of a study on electrode floating potential formation in a hot-cathode discharge plasma. The electron component of the plasma is composed from two populations. The high temperature component develops from primary electrons and the cool component from secondary electrons born by ionisation of cold neutral gas. A static, kinetic plasma-sheath model is use to calculate the pre-sheath potential and the floating potential of the electrode. For hot primary electrons a truncated Maxwellian distribution is assumed. The plasma system is also modelled numerically with a dynamic, electrostatic particle simulation. The plasma source injects temporally equal fluxes of ions and electrons with half-Maxwellian velocities. Again, the hot electron distribution is truncated in the high velocity tail. The plasma parameters, such as ion temperature and mass, electron temperatures, discharge voltages, etc. correspond to experimental values. The experimental measurements of the electrode floating potential are performed in weakly magnetised plasma produced with hot cathode discharge in argon gas. Theoretical, simulation and experimental results are compared and they agree very well.(author)

Maiden Voyage of the Under-Ice Float

Science.gov (United States)

Shcherbina, A.; D'Asaro, E. A.; Light, B.; Deming, J. W.; Rehm, E.

2016-02-01

The Under-Ice Float (UIF) is a new autonomous platform for sea ice and upper ocean observations in the marginal ice zone (MIZ). UIF is based on the Mixed Layer Lagrangian Float design, inheriting its accurate buoyancy control and relatively heavy payload capability. A major challenge for sustained autonomous observations in the MIZ is detection of open water for navigation and telemetry surfacings. UIF employs the new surface classification algorithm based on the spectral analysis of surface roughness sensed by an upward-looking sonar. A prototype UIF was deployed in the MIZ of the central Arctic Ocean in late August 2015. The main payload of the first UIF was a bio-optical suit consisting of upward- and downward hyperspectral radiometers; temperature, salinity, chlorophyll, turbidity, and dissolved oxygen sensors, and a high-definition photo camera. In the early stages of its mission, the float successfully avoided ice, detected leads, surfaced in open water, and transmitted data and photographs. We will present the analysis of these observations from the full UIF mission extending into the freeze-up season.

a Design of the Driver Airbag Module with Floating Horn Assembly

Science.gov (United States)

Suh, Chang-Min; Lee, Young-Hoon; Suh, Duck-Young

The driver airbag system is designed as a supplemental restraint system in addition to the seatbelt, and is designed to protect the driver's head and chest against severe injury by a device that is actuated in case of vehicle's fronted impact. Deployment of an airbag module with floating horn assembly is a highly dynamic process. The concept of driver airbag module with floating horn assembly and aluminum emblem is presented as a useful parameter when the airbag deploys and the energy is evaluated as performance factor in airbag module. Floating horn assembly is also one of the major factors for driver airbag module design to perform its horn function and check the package between driver airbag module and steering wheel. This study on the design of driver airbag module with floating horn assembly proved the feasibility as a new safety device. However, the system level study is needed for decrease of passenger injury. This study can be used for the implementation of a prototype of DABM with floating horn device.

The capture rate of free-floating planets in our galaxy

Science.gov (United States)

Goulinski, N.; Ribak, E. N.

2017-09-01

We propose that planetary nebulae and supernova remnants may constitute a significant source of free-floating planets. With a large population of free-floating planets, the rate at which these planets get captured by planetary systems may be non-negligible. We predict that about one out of every 100 sub-solar stars are expected to experience a capture of a free-floating planet during their lifetime. The capture cross section calculated through three-body scattering simulations in vacuum conditions. Since planetary systems usually contain multiple planets, and dissipation processes where not included in the simulation, the capture rate may be higher.