Academic literature on the topic 'Deep water flow; Ocean; Seawater'
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Journal articles on the topic "Deep water flow; Ocean; Seawater"
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Uchida, Tsutomu, Ike Nagamine, Itsuka Yabe, Tatsunori Fukumaki, Ai Oyama, Brandon Yoza, Norio Tenma, and Stephen M. Masutani. "Dissolution Process Observation of Methane Bubbles in the Deep Ocean Simulator Facility." Energies 13, no. 15 (August 1, 2020): 3938. http://dx.doi.org/10.3390/en13153938.
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To investigate the temperature dependency of the methane bubble dissolution rate, buoyant single methane bubbles were held stationary in a countercurrent water flow at a pressure of 6.9 MPa and temperatures ranging from 288 K to 303 K. The 1 to 3 mm diameter bubbles were analyzed by observation through the pressure chamber viewport using a bi-telecentric CCD camera. The dissolution rate in artificial seawater was approximately two times smaller than that in pure water. Furthermore, it was observed that the methane bubble dissolution rate increased with temperature, suggesting that bubble dissolution is a thermal activation process (the activation energy is estimated to be 9.0 kJ/mol). The results were different from the expected values calculated using the governing equation for methane dissolution in water. The dissolution modeling of methane bubbles in the mid-to-shallow depth of seawater was revised based on the current results.
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Nihous, Gérard C. "A Preliminary Assessment of Ocean Thermal Energy Conversion Resources." Journal of Energy Resources Technology 129, no. 1 (July 7, 2006): 10–17. http://dx.doi.org/10.1115/1.2424965.
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Worldwide power resources that could be extracted from Ocean Thermal Energy Conversion (OTEC) plants are estimated with a simple one-dimensional time-domain model of the thermal structure of the ocean. Recently published steady-state results are extended by partitioning the potential OTEC production region in one-degree-by-one-degree “squares” and by allowing the operational adjustment of OTEC operations. This raises the estimated maximum steady-state OTEC electrical power from about 3TW(109kW) to 5TW. The time-domain code allows a more realistic assessment of scenarios that could reflect the gradual implementation of large-scale OTEC operations. Results confirm that OTEC could supply power of the order of a few terawatts. They also reveal the scale of the perturbation that could be caused by massive OTEC seawater flow rates: a small transient cooling of the tropical mixed layer would temporarily allow heat flow into the oceanic water column. This would generate a long-term steady-state warming of deep tropical waters, and the corresponding degradation of OTEC resources at deep cold seawater flow rates per unit area of the order of the average abyssal upwelling. More importantly, such profound effects point to the need for a fully three-dimensional modeling evaluation to better understand potential modifications of the oceanic thermohaline circulation.
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Lu, Ling, Hong Pan, Wei Fan, and Yong Cai. "A Preliminary Study on Efficiency of Air-Lift Upwelling." Advanced Materials Research 422 (December 2011): 424–29. http://dx.doi.org/10.4028/www.scientific.net/amr.422.424.
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Upwelling of deep seawater using air-lift system to the region, where sunlight reaches, can produce the ocean farm since deep seawater contains high concentration of nutrient such as nitrogen and phosphorus. The efficiency of air-lift upwelling along a 300 mm diameter vertical pipe has been studied in this paper. Using a plexiglass pipe as the upwelling-pipe, a laboratory experiment was performed in a 4.5 m deep tank to obtain the flow rate ratio of water to gas. We also performed numerical experiments using commercial CFD software FLUENT 6.3 based on conditions of experiment. Both the experiment and simulation have shown promising results that the upwelling flow rate increased as the injection air flow rate increased, and there was a good lineal relationship between them in a certain range. The value of the lifting efficiency is about 2-3. Further work will have to determine the efficiency of air-lift upwelling under real ocean conditions and the minimum power of air pump required to sustain air-lift system.
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Anthony, K. R. N., G. Diaz-Pulido, N. Verlinden, B. Tilbrook, and A. J. Andersson. "Benthic buffers and boosters of ocean acidification on coral reefs." Biogeosciences 10, no. 7 (July 19, 2013): 4897–909. http://dx.doi.org/10.5194/bg-10-4897-2013.
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Abstract. Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (NCP) and calcification (NCC). Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia) contribute to changes in the seawater aragonite saturation state (Ωa). Results of flume studies using intact reef habitats (1.2 m by 0.4 m), showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm), macroalgae (Chnoospora implexa), turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm) and high flow (35 compared to 8 cm s−1). In contrast, branching corals (Acropora aspera) increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm) during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1) and exacerbated by acidification. Calcifying macroalgae (Halimeda spp.) raised Ωa by day (by around 0.13 h−1), but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from benthic communities with four different compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water-residence times in neighbouring areas dominated by turfs, macroalgae and carbonate sand.
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Anthony, K. R. N., G. Diaz-Pulido, N. Verlinden, B. Tilbrook, and A. J. Andersson. "Benthic buffers and boosters of ocean acidification on coral reefs." Biogeosciences Discussions 10, no. 2 (February 1, 2013): 1831–65. http://dx.doi.org/10.5194/bgd-10-1831-2013.
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Abstract. Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (pn) and calcification (gn). Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia) contribute to changes in seawater aragonite saturation state (Ωa). Results of flume studies showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm), macroalgae (Chnoospora implexa), turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm) and high flow (35 compared to 8 cm s−1). In contrast, branching corals (Acropora aspera) increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm) during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1) and exacerbated by acidification. Calcifying macroalgae (Halimeda spp.) raised Ωa by day (by around 0.13 h−1), but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from four different benthic compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water residence times in neighbouring areas dominated by turfs, macroalgae and potentially sand.
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Yanagawa, Katsunori, Anja Breuker, Axel Schippers, Manabu Nishizawa, Akira Ijiri, Miho Hirai, Yoshihiro Takaki, et al. "Microbial Community Stratification Controlled by the Subseafloor Fluid Flow and Geothermal Gradient at the Iheya North Hydrothermal Field in the Mid-Okinawa Trough (Integrated Ocean Drilling Program Expedition 331)." Applied and Environmental Microbiology 80, no. 19 (July 25, 2014): 6126–35. http://dx.doi.org/10.1128/aem.01741-14.
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ABSTRACTThe impacts of lithologic structure and geothermal gradient on subseafloor microbial communities were investigated at a marginal site of the Iheya North hydrothermal field in the Mid-Okinawa Trough. Subsurface marine sediments composed of hemipelagic muds and volcaniclastic deposits were recovered through a depth of 151 m below the seafloor at site C0017 during Integrated Ocean Drilling Program Expedition 331. Microbial communities inferred from 16S rRNA gene clone sequencing in low-temperature hemipelagic sediments were mainly composed of members of theChloroflexiand deep-sea archaeal group. In contrast, 16S rRNA gene sequences of marine group IThaumarchaeotadominated the microbial phylotype communities in the coarse-grained pumiceous gravels interbedded between the hemipelagic sediments. Based on the physical properties of sediments such as temperature and permeability, the porewater chemistry, and the microbial phylotype compositions, the shift in the physical properties of the sediments is suggested to induce a potential subseafloor recharging flow of oxygenated seawater in the permeable zone, leading to the generation of variable chemical environments and microbial communities in the subseafloor habitats. In addition, the deepest section of sediments under high-temperature conditions (∼90°C) harbored the sequences of an uncultivated archaeal lineage of hot water crenarchaeotic group IV that may be associated with the high-temperature hydrothermal fluid flow. These results indicate that the subseafloor microbial community compositions and functions at the marginal site of the hydrothermal field are highly affected by the complex fluid flow structure, such as recharging seawater and underlying hydrothermal fluids, coupled with the lithologic transition of sediments.
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WEI, GUANG-YI, HONG-FEI LING, DA LI, WEI WEI, DAN WANG, XI CHEN, XIANG-KUN ZHU, FEI-FEI ZHANG, and BIN YAN. "Marine redox evolution in the early Cambrian Yangtze shelf margin area: evidence from trace elements, nitrogen and sulphur isotopes." Geological Magazine 154, no. 6 (March 22, 2017): 1344–59. http://dx.doi.org/10.1017/s0016756817000115.
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AbstractNitrogen is an essential element for biological activity, and nitrogen isotopic compositions of geological samples record information about both marine biological processes and environmental evolution. However, only a few studies of N isotopes in the early Cambrian have been published. In this study, we analysed nitrogen isotopic compositions, as well as trace elements and sulphur isotopic compositions of cherts, black shales, carbonaceous shales and argillaceous carbonates from the Daotuo drill core in Songtao County, NE Guizhou Province, China, to reconstruct the marine redox environment of both deep and surface seawater in the study area of the Yangtze shelf margin in the early Cambrian. The Mo–U covariation pattern of the studied samples indicates that the Yangtze shelf margin area was weakly restricted and connected to the open ocean through shallow water flows. Mo and U concentrations, δ15Nbulk and δ34Spy values of the studied samples from the Yangtze shelf margin area suggest ferruginous but not sulphidic seawater and low marine sulphate concentration (relatively deep chemocline) in the Cambrian Fortunian and early Stage 2; sulphidic conditions (shallow chemocline and anoxic photic zone) in the upper Cambrian Stage 2 and lower Stage 3; and the depression of sulphidic seawater in the middle and upper Cambrian Stage 3. Furthermore, the decreasing δ15N values indicate shrinking of the marine nitrate reservoir during the middle and upper Stage 3, which reflects a falling oxygenation level in this period. The environmental evolution was probably controlled by the changing biological activity through its feedback on the local marine environment.
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Archer, D. "A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin." Biogeosciences Discussions 11, no. 6 (June 3, 2014): 7853–900. http://dx.doi.org/10.5194/bgd-11-7853-2014.
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Abstract. A two-dimensional model of a passive continental margin was adapted to the simulation of the methane cycle on Siberian continental shelf and slope, attempting to account for the impacts of glacial/interglacial cycles in sea level, alternately exposing the continental shelf to freezing conditions with deep permafrost formation during glacial times, and immersion in the ocean in interglacial times. The model is used to gauge the impact of the glacial cycles, and potential anthropogenic warming in the deep future, on the atmospheric methane emission flux, and the sensitivities of that flux to processes such as permafrost formation and terrestrial organic carbon (Yedoma) deposition. Hydrological forcing drives a freshening and ventilation of pore waters in areas exposed to the atmosphere, which is not quickly reversed by invasion of seawater upon submergence, since there is no analogous saltwater pump. This hydrological pump changes the salinity enough to affect the stability of permafrost and methane hydrates on the shelf. Permafrost formation inhibits bubble transport through the sediment column, by construction in the model. The impact of permafrost on the methane budget is to replace the bubble flux by offshore groundwater flow containing dissolved methane, rather than accumulating methane for catastrophic release when the permafrost seal fails during warming. By far the largest impact of the glacial/interglacial cycles on the atmospheric methane flux is attenuation by dissolution of bubbles in the ocean when sea level is high. Methane emissions are highest during the regression (soil freezing) part of the cycle, rather than during transgression (thawing). The model-predicted methane flux to the atmosphere in response to a warming climate is small, relative to the global methane production rate, because of the ongoing flooding of the continental shelf. A slight increase due to warming could be completely counteracted by sea level rise on geologic time scales, decreasing the efficiency of bubble transit through the water column. The methane cycle on the shelf responds to climate change on a long time constant of thousands of years, because hydrate is excluded thermodynamically from the permafrost zone by water limitation, leaving the hydrate stability zone at least 300 m below the sediment surface.
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Friðleifsson, Guðmundur Ó., Wilfred A. Elders, Robert A. Zierenberg, Ari Stefánsson, Andrew P. G. Fowler, Tobias B. Weisenberger, Björn S. Harðarson, and Kiflom G. Mesfin. "The Iceland Deep Drilling Project 4.5 km deep well, IDDP-2, in the seawater-recharged Reykjanes geothermal field in SW Iceland has successfully reached its supercritical target." Scientific Drilling 23 (November 30, 2017): 1–12. http://dx.doi.org/10.5194/sd-23-1-2017.
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Abstract. The Iceland Deep Drilling Project research well RN-15/IDDP-2 at Reykjanes, Iceland, reached its target of supercritical conditions at a depth of 4.5 km in January 2017. After only 6 days of heating, the measured bottom hole temperature was 426 °C, and the fluid pressure was 34 MPa. The southern tip of the Reykjanes peninsula is the landward extension of the Mid-Atlantic Ridge in Iceland. Reykjanes is unique among Icelandic geothermal systems in that it is recharged by seawater, which has a critical point of 406 °C at 29.8 MPa. The geologic setting and fluid characteristics at Reykjanes provide a geochemical analog that allows us to investigate the roots of a mid-ocean ridge submarine black smoker hydrothermal system. Drilling began with deepening an existing 2.5 km deep vertical production well (RN-15) to 3 km depth, followed by inclined drilling directed towards the main upflow zone of the system, for a total slant depth of 4659 m ( ∼ 4.5 km vertical depth). Total circulation losses of drilling fluid were encountered below 2.5 km, which could not be cured using lost circulation blocking materials or multiple cement jobs. Accordingly, drilling continued to the total depth without return of drill cuttings. Thirteen spot coring attempts were made below 3 km depth. Rocks in the cores are basalts and dolerites with alteration ranging from upper greenschist facies to amphibolite facies, suggesting that formation temperatures at depth exceed 450 °C. High-permeability circulation-fluid loss zones (feed points or feed zones) were detected at multiple depth levels below 3 km depth to bottom. The largest circulation losses (most permeable zones) occurred between the bottom of the casing and 3.4 km depth. Permeable zones encountered below 3.4 km accepted less than 5 % of the injected water. Currently, the project is attempting soft stimulation to increase deep permeability. While it is too early to speculate on the energy potential of this well and its economics, the IDDP-2 is a milestone in the development of geothermal resources and the study of hydrothermal systems. It is the first well that successfully encountered supercritical hydrothermal conditions, with potential high-power output, and in which on-going hydrothermal metamorphism at amphibolite facies conditions can be observed. The next step will be to carry out flow testing and fluid sampling to determine the chemical and thermodynamic properties of the formation fluids.
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Luz, Leticia G., Thiago P. Santos, Timothy I. Eglinton, Daniel Montluçon, Blanca Ausin, Negar Haghipour, Silvia M. Sousa, Renata H. Nagai, and Renato S. Carreira. "Contrasting late-glacial paleoceanographic evolution between the upper and lower continental slope of the western South Atlantic." Climate of the Past 16, no. 4 (July 16, 2020): 1245–61. http://dx.doi.org/10.5194/cp-16-1245-2020.
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Abstract. The number of sedimentary records collected along the Brazilian continental margin has increased significantly in recent years, but relatively few are located in shallow waters and register paleoceanographic processes in the outer shelf–middle slope prior to 10–15 ka. For instance, the northward flow up to 23–24∘ S of cold and fresh shelf waters sourced from the Subantarctic region is an important feature of current hydrodynamics in the subtropical western South Atlantic Ocean, and yet limited information is available for the long-term changes of this system. Herein, we considered a suite of organic and inorganic proxies – alkenones-derived sea surface temperature (SST), δD-alkenones, δ18O of planktonic foraminifera, and ice-volume free seawater δ18OIVF−SW – in sediment from two cores (RJ-1501 and RJ-1502) collected off the Rio de Janeiro Shelf (SE Brazilian continental shelf) to shed light on SST patterns and relative salinity variations since the end of the last glacial cycle in the region and the implications of these processes over a broader spatial scale. The data indicate that, despite the proximity (∼40 km apart) of both cores, apparently contradictory climatic evolution occurred at the two sites, with the shallower (deeper) core RJ-1501 (RJ-1502) showing consistently cold (warm) and fresh (salt) conditions toward the Last Glacial Maximum (LGM) and last deglaciation. This can be reconciled by considering that the RJ-1501 core registered a signal from mid- to high latitudes on the upper slope off Rio de Janeiro represented by the influence of the cold and fresh waters composed of Subantarctic Shelf Water and La Plata Plume Water transported northward by the Brazilian Coastal Current (BCC). The data from core RJ-1502 and previous information for deep-cores from the same region support this interpretation. In addition, alkenone-derived SST and δ18OIVF−SW suggest a steep thermal and density gradient formed between the BCC and Brazil Current (BC) during the last climate transition which, in turn, may have generated perturbations in the air–sea heat flux with consequences for the regional climate of SE South America. In a scenario of future weakening of the Atlantic Meridional Overturning Circulation, the reconstructed gradient may become a prominent feature of the region.
Dissertations / Theses on the topic "Deep water flow; Ocean; Seawater"
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Reynolds, Ben Christopher. "Neodymium and lead isotope time series from Atlantic ferromanganese crusts." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342540.
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AlMuhanna, Khalid A. "Acoustic modeshape inversion using deep water ambient noise measurements." Fairfax, VA : George Mason University, 2008. http://hdl.handle.net/1920/3214.
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Thesis (M.S.)--George Mason University, 2008.Vita: p. 69. Thesis director: Kathleen E. Wage. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering. Title from PDF t.p. (viewed Aug. 27, 2008). Includes bibliographical references (p. 67-68). Also issued in print.
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Un, Ka Man. "Real-time ocean optical fiber sensing of phytoplankton for studies in size distribution, concentration and biomass." HKBU Institutional Repository, 1999. http://repository.hkbu.edu.hk/etd_ra/265.
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Clesi, Vincent. "Formation de la Terre et de Mars : étude expérimentale et numérique." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22750/document.
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La formation des noyaux planétaires métalliques est un évènement majeur pour l’évolution des propriétés physico-chimiques des planètes telluriques telles que nous les connaissons aujourd’hui. En effet, l’abondance des éléments sidérophiles (i.e. qui ont des affinités chimiques avec les phases métalliques) dans les manteaux planétaires s’explique par les conditions dans lesquelles se sont séparées les phases métalliques et silicatées. Au premier rang de ces conditions se trouvent la pression, la température et la fugacité d’oxygène. La distribution des éléments dans le noyau et le manteau ne peut en effet s’expliquer que pour un équilibre obtenu dans un océan magmatique profond, donc à haute pression et haute température ; et dans des conditions d’oxydo-réduction variables, dont l’évolution la plus probable est de passer d’un état réduit à un état oxydé. Un autre paramètre important est la présence ou non d’eau dans l’océan magmatique primitif. En effet, nous disposons de plus en plus d’arguments permettant d’expliquer l’arrivée des éléments volatils, notamment l’eau, pendant l’accrétion, à partir de briques élémentaires qui contiennent ces éléments. Si l’eau est présente tout au long de l’accrétion, et donc pendant la ségrégation du noyau, elle peut donc avoir un effet sur ce dernier phénomène. Dans cette hypothèse, nous avons mené des expériences de haute pression et haute température permettant de modéliser expérimentalement la formation du noyau en condition hydratée. Ces expériences nous ont permis de montrer que la présence d’eau a un effet sur l’évolution de l’état d’oxydation des manteaux planétaires. Cette évolution oxydo-réductive nous a permis de contraindre des modèles d’accrétion basés sur un mélange de chondrites EH et CI, qui confirment des modèles construits à partir de données isotopiques. Ces modèles nous ont permis de contraindre les concentrations primitives maximum en eau probables sur Terre (1,2-1,8 % pds.) et sur Mars (2,5-3,5 % pds.). D’autre part, nos avons mis en évidence le caractère lithophile (i.e. qui a des affinités chimiques avec les phases silicatées) de l’hydrogène à haute pression, a contrario de plusieurs études précédentes. De ce fait, la différence entre les concentrations initiales élevées en eau que nous obtenons dans nos modèles d’accrétion et les concentrations en eau estimées sur Terre et sur Mars actuellement (2000 ppm et 200 ppm, respectivement) ne peut pas être expliquée par un réservoir d’hydrogène dans le noyau. Enfin, pour améliorer les modèles de formation du noyau, nous avons mis en évidence, par des modèles numériques, l’effet important de la viscosité de l’océan magmatique sur le taux d’équilibre entre noyaux et manteaux des planètes telluriques. Cela nous mène à ré-évaluer les modèles de formation des planètes telluriques basés sur des résultats expérimentaux à l’équilibre, notamment l’extension maximale de l’océan magmatique. L’évolution de la viscosité de l’océan magmatique a donc un impact important sur la composition finale des noyaux planétaires (par exemple les teneurs en soufre, oxygène ou silicium des noyaux terrestres et martiens)The formation of the metallic planetary cores is a major event regarding to the evolution of physical and chemical properties of the telluric planets as we know it today. Indeed, the siderophile elements (i.e. which has affinities with metallic phases) abundances in planetary mantles is explained by the conditions of core-mantle segregation. Among these conditions, pressure, temperature and oxygen fugacity are the main ones controlling distribution of the elements between mantle and core. This distribution can only be explained by an equilibrium between metal and silicate obtained in a deep magma ocean, which implies high pressure and high temperature of equilibrium. Moreover, the oxygen fugacity must have varied during core-mantle segregation, in a reduced-to-oxidized path most probably. Another important parameter is whether or not water is present in the primordial magma ocean. Indeed, we now have more and more lines of evidences showing that the volatile elements, especially water, arrived during accretion and therefore during the core-mantle segregation, which means that water can have an effect on the latter phenomenon. Considering this hypothesis, we performed several high pressure-high temperature experiments which allowed us to model the formation of the core under hydrous conditions. These experiments demonstrated that water has a significant effect on the redox state evolution of planetary mantles. We use this redox evolution to constrain models of planetary accretions, based on a mix of EH and CI chondrites, showing a good agreement with models based on isotopic data. The output of these models is the maximum initial concentration in water on the Earth (1.2 -1.8 %wt) and on Mars (2.5-3.5 %wt). Furthermore, these experiments showed a lithophile behavior (i.e. which has affinities with silicated phases) of hydrogen at high pressures, contrary to previous studies. Therefore, the difference between high initial concentrations in water yielded by our accretion models and the estimated actual concentrations on the Earth and Mars (2000 ppm and 200 ppm, respectively) cannot be explained by a hydrogen reservoir in the core. Finally, to improve the models of core-mantle segregation, we showed by numerical simulations the important effect of the magma ocean viscosity on the equilibrium between planetary mantles and cores. it lead us to reevaluate the models of accretion based on experimental data, especially the maximum extent of magma oceans. The evolution of the magma ocean viscosity has therefore significant implications on the final composition of planetary cores (for instance on the sulfur, oxygen and silicon content of the Earth’s and Mars’ core)
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Henderson, Samuel Straker. "Tracking deep-water flow on Eirik drift over the past 160 kyr linking deep-water changes to freshwater fluxes /." 2009. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051018.
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Chen, Wang-Ching, and 陳旺卿. "Study on the planning and strategy of aquaculture industry using deep seawater--A Case Study of Dannanao Deep Ocean Water Park in Yilan County." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9k9267.
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博士國立臺灣大學
漁業科學研究所
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Currently the utilization of deep ocean water (DOW or deep sea water/DSW) is receiving much attention due to its high added value with large quantity, high productivity and potential for recycling energy. Deep ocean water possesses three main characteristics: low temperature, cleanliness and nutrient richness. In eastern Taiwan, the steep coastal landforms make it a great potential to develop deep ocean water industry. In order to promote DOW related industry, Yilan County government in eastern Taiwan has established DOW Park in Nan''ao Township. Taking Danan’ao Deep Ocean Water Park as an example, this research has collected the utilization methods, draft, and the prices of deep ocean water of America’s NELHA and Japan, and had a preliminary calculation of benefit assessment for deep ocean water utilization in the Park. In addition, it has also briefly introduced the utilization conditions of deep ocean water extraction pipes of the United States, Japan, and Taiwan. Related contents have been summarized as below: (1) the pipe diameter of America’s deep ocean water extraction pipe is designed to be larger, whose costs are lower. The deep ocean water charges are 0.074 US dollars per 1,000 gallons (About 0.66 NT dollars per ton). (2) Japan’s deep ocean water exploitation scale is smaller. Due to the heavy weathers, the pipe diameter is mainly designed to be small caliber. In order to improve pipe safety, steel wires have been specially designed to cover the HDPE pipe to strengthen the intensity of the pipelines. Deep ocean raw water charges are 300-540 Yen per ton, in which Okinawa Prefecture Deep Ocean Water Research Institute charges 400 Yen per ton (about 138 NT dollars per ton) for raw material processing, but charges only 6 Yen per ton (about 2 NT dollars per ton) for agriculture and aquaculture. (3) The benefit assessment of deep ocean water utilization on aquaculture industry has been analyzed as Plan A and Plan B. Plan A has designed 0.9 hectare of the land for segmented utilization of aquaculture, the fish production area is 0.55 hectares, estimating the annual output value to be 66.5 million dollars, the benefit before tax to be 27.6 million dollars, and daily water consumption to be 7,200 tons. Plan B has designed 5.5 hectares of the land for segmented utilization of aquaculture, the fish production area is 2.4 hectares, estimating the annual output value to be 411 million dollars, the benefit before tax to be 185 million dollars, and daily water consumption to be 46,000 tons. The maximum water charges for making profits of Plan A and B are 10.5 dollars/ton and 11.0 dollars/ton respectively. If referring to the cost of water prices of America’s NELHA or the water price standards Japan provides for agriculture and fishery industry, abundant profits could be expected if utilizing deep ocean water on aquaculture industry, which is worth government’s vigorous promotion. Through commercializing the DOW resources and introducing non-governmental investment from the private sectors, the DOW Park aims to promote regional development and upgrade the related industries. In the present study, we investigated the potential market demands, technical conditions and its biological natures of developing salmon aquaculture at Nan''ao DOW Park. It aims to take advantage of the characteristics of DOW to propose industrial strategies on salmon aquaculture with DOW and establish the developmental goals at different times. Ingeneral, three stages i.e. short, medium and long-term stages will be analyzed respectively. In the short-term stage, the objective of harvested salmon is to achieve 30,000 mt yr-1 for the domestic market demands in the common size of 1 kg-5 kg fish-1. In the medium and long-term stages, the objectives are focusing on the markets in Japan, China and Southeast Asian countries, aiming to achieve the salmon harvest with 300,000 mt-500,000 mt year-1. The domestic market of the DOW salmon industry is estimated to reach approximately US$ 330 million (NT$ 10 billion) of linking industrial cluster and value chain. The study may also provide the government an innovative strategy and market orientation towards DOW industry guidance as well an investment consideration for enterprises having an interest in developing DOW related industry.
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Zoeller, Khalhela. "Insights into the distribution and mobility of metals in the sheeted dike complex formed at fast-spreading ridges (Pito Deep, EPR)." Thesis, 2014. http://hdl.handle.net/1828/5264.
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Hydrothermal fluid circulation is an important process in the formation and evolution of ocean crust. A tectonic window located at Pit Deep (NE corner Easter Microplate) provides an ideal location to examine a 3-dimensional view of ocean crust formed at the fast-spreading East Pacific Rise. This study focuses on the base metal (Cu, Ni, Mn, Co, Zn, and Pb) content of the bulk rock and mineral components in the sheeted dike complex. There is no observable trend of metal mobility with depth, geographic location, or dominant alteration phase. Secondary mineral analyses (using LA-ICP-MS) show that metals are redistributed throughout the sheeted dikes, entering into secondary sulphides, chlorite, and amphibole. Temperature and mineral stability is a primary control of metal mobility in these rocks. Due to highly variable metal concentrations and observed temperatures of alterations, the hydrothermal cell is suggested to be a continuously evolving system, and can cause the large variability observed in the metal distribution in the sheeted dikes.Graduate
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Book chapters on the topic "Deep water flow; Ocean; Seawater"
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Edmunds, W. M. "Silent Springs: Groundwater Resources Under Threat." In Managing Water Resources, Past and Present. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780199267644.003.0008.
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Springs are symbolic of the sustainability of life on earth. Since the earliest times flowing springs have been held as sacred and as a subject of awe and fascination. Subterranean water is identified in the creation myths on Babylonian tablets, where waters above the earth are separated from the ‘water of the deep’. The persistence of these creation myths is still reflected in the Arabic word ain or ayun, which has the double meaning of spring and eye (Issar 1991). Springs were the eyes of the gods. Springs (or fountains) were the focal point of many events in the Bible and other religious texts, and were the subject of veneration, as in Psalm 104: 10, ‘He sendeth the springs into the valleys, which run among the hills Modern scientific understanding of the origins of spring flow dates from the seventeenth century. The earliest explanations of the hydrological cycle, often termed the reversed hydrological cycle, probably stem from biblical sources (Ecclesiastes 1: 7). The unexplained constancy of the ocean volume was accounted for by the return of seawater through the rocks, which then purified them and returned the water to the surface as freshwater rivers and springs. This interpretation of the hydrological cycle persisted through the writings of ancient Greece and Rome as in Seneca’s Quaestiones Naturales and into the Middle Ages (Tuan 1968) until correctly explained by Edmond Halley(Halley 1691). In modern society spring waters are valued highly because they still embody an element of mystery and bring us face to face with the subsurface expression of the hydrological cycle or ‘groundwater’. There is also traditional belief that spring waters represent a source of perennial pure water. The properties of pure spring water command a high market value and in a world where tap water is (often wrongly) perceived as something less pure, the bottled water image-makers seek after evidence of the purity, longevity, and healing properties of the spring, with a zeal that echoes the reverence accorded to spring waters by early philosophers. The objective of this chapter is to explore the reasons for the decline of natural springs and the fragility of groundwater resources in general.
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"Water mass and tracer analysis of the deep flow in the Atlantic Ocean." In The Oceanic Thermohaline Circulation: An Introduction, 45–78. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-48039-8_4.
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Bayly, Brian. "Disequilibrium 1: Potential Gradients and Flows." In Chemical Change in Deforming Materials. Oxford University Press, 1993. http://dx.doi.org/10.1093/oso/9780195067644.003.0008.
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As in Chapter 2, so again here the intention is to review ideas that are already familiar, rather than to introduce the unfamiliar; to build a springboard, but not yet to leap off into space. The familiar idea is of flow down a gradient—water running downhill. Parallels are electric current in a wire, salt diffusing inland from the sea, heat flowing from the fevered brow into the cool windowpane, and helium diffusing through the membrane of a helium balloon. For any of these, we can imagine a linear relation: . . . Flow rate across a unit area = (conductivity) x (driving gradient) . . . where the conductivity retains a constant value, and if the other two quantities change, they do so in a strictly proportional way. Real life is not always so simple, but this relation serves to introduce the right quantities, some suitable units and some orders of magnitude. For present purposes, the second and fourth of the examples listed are the most relevant. To make comparison easier we imagine a barrier through which salt can diffuse and through which water can percolate, but we imagine circumstances such that only one process occurs at a time. Specifically, imagine a lagoon separated from the ocean by a manmade dike of gravel and sand 4 m thick, as in Figure 3.1. If the lagoon is full of seawater but the water levels on the two sides of the dike are unequal, water will percolate through the dike, whereas if the levels are the same and the dike is saturated but the lagoon is fresh water, salt will diffuse through but there will be no bulk flow of water. (More correctly, because seawater and fresh water have different densities, and because of other complications, the condition of no net water flow would be achieved in circumstances a little different from what was just stated. For present purposes all we need is the idea that conditions exist where water does not percolate but salt does diffuse.) For flow of water driven by a pressure gradient, suitable units are shown in the upper part of Table 3.1 and for diffusion of salt driven by a concentration gradient, suitable units are shown in the lower part.
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Janani, E. Srie Vidhya, and A. Rehash Rushmi Pavitra. "Cost Effective Smart Farming With FARS-Based Underwater Wireless Sensor Networks." In Handbook of Research on Implementation and Deployment of IoT Projects in Smart Cities, 296–316. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-9199-3.ch018.
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Smart farming is a key to develop sustainable agriculture, involving a wide range of information and communication technologies comprising machinery, equipment, and sensors at different levels. Seawater, which is available in huge volumes across the planet, should find its optimal way through irrigation purposes. On the other hand, underwater wireless sensor networks (UWSNs) finds its way actively in current researches where sensors are deployed for examining discrete activities such as tactical surveillance, ocean monitoring, offshore analysis, and instrument observing. All these activities are based on a radically new type of sensors deployed in ocean for data collection and communication. A lightweight Hydro probe II sensor quantifies the soil moisture and water flow level at an acknowledged wavelength. The freshwater absorption repository system (FARS) is matured based on the mechanics of UWSNs comprised of SBE 39 and pressure sensor for analyzing atmospheric pressure and temperature. This necessitates further exploration of FARS to complement smart farming. Discrete routing protocols have been designed for data collection in both compatible and divergent networks. Clustering is an effective approach to increase energy efficient data transmission, which is crucial for underwater networks. Furthermore, the chapter attempts to facilitate seawater irrigation to the farm lands through reverse osmosis (RO) process. Also, the proposed irrigation pattern exploits residual water from the RO process which is identified to be one among the suitable growing conditions for salicornia seeds and mangrove trees. Ultimately, the cost-effective technology-enabled irrigation methodology suggested offers farm-related services through mobile phones that increase flexibility across the overall smart farming framework.
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Bowers, David George, and Emyr Martyn Roberts. "4. The tide in shelf seas." In Tides: A Very Short Introduction, 50–64. Oxford University Press, 2019. http://dx.doi.org/10.1093/actrade/9780198826637.003.0004.
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‘The tide in shelf seas’ describes progressive waves, standing waves, and what happens when a shelf sea is in resonance, using the example of the Gulf of St Vincent off the south Australian coast. It also considers the effect of Earth rotation and tides in shallow water, where the rare feature is double high water or double low water. The great ocean basins are bordered by shallow seas lying on the continental shelves. Shelf seas are generally less than 200 metres deep and vary in width from almost nothing to hundreds of kilometres. It is in these shallow seas and the rivers that flow into them that the most spectacular tides are found.
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Sherratt, Thomas N., and David M. Wilkinson. "Why is the Sea Blue?" In Big Questions in Ecology and Evolution. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780199548606.003.0012.
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One answer to this chapter’s question is straightforward and based on high-school physics. The early SCUBA divers quickly discovered that if they took underwater colour photographs, even if they were only a few metres down, their pictures had a strong blue cast to them. However, if they illuminated their subjects with a flash, then a more colourful world emerged in their pictures—especially if they were photographing the rich diversity of highly coloured fish that can be found in some parts of the tropics. The reason for the blueness is that as sunlight passes through water the colours of the spectrum are absorbed at different rates, with the long wavelengths (e.g. red) absorbed first and the higher-energy shorter wavelengths (e.g. blue) penetrating deeper into the depths. It follows that underwater available light is predominantly blue and that any light reflected from within the water body is more likely to be from the bluer end of the spectrum of visible light. So, light coming from the sea to our eyes is mainly blue because these wavelengths are least absorbed; indeed oceanographers who have studied some of the cleanest waters describe them as looking ‘violet blue’. As biologists we are interested in a more ecological answer to the question, ‘Why is the sea blue’? The physics explanation only works if seawater is reasonably clear, and it is this clarity that biologists need to explain. Consider our opening quotation, which comes from Peter Matthiessen’s book describing early attempts to film the great white shark in its natural habitat. It raises an interesting ecological question—why can a SCUBA diver or snorkeler see where they are going in the ocean? Put another way, why is the sea blue rather than green? The upper layer of the ocean with enough light for photosynthesis is called the euphotic zone (defined as extending down to the point where only 1% of photosynthetically usable light is present compared with surface light levels); this is often only a few tens of metres deep, but in extremely clear water near Easter Island in the Pacific it has recently been found to extend down to 170 m depth.
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Bianchi, Thomas S. "Estuarine Science and Biogeochemical Cycles." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0006.
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Estuaries are commonly described as semi-enclosed bodies of water, situated at the interface between land and ocean, where seawater is measurably diluted by the inflow of freshwater (Hobbie, 2000). The term “estuary,” derived from the Latin word aestuarium, means marsh or channel (Merriam-Webster, 1979). These dynamic ecosystems have some of the highest biotic diversity and production in the world. Not only do they provide a direct resource for commercially important estuarine species of fishes and shellfish, but they also provide shelter and food resources for commercially important shelf species that spend some of their juvenile stages in estuarine marshes. For example, high fish and shellfish production in the northern Gulf of Mexico is strongly linked with discharge from the Mississippi and Atchafalaya rivers and their associated estuarine wetlands (Chesney and Baltz, 2001). Commercial fishing in this region typically brings in 769 million kg of seafood with a value of $575 million. Fisheries production and coastal nutrient enrichment, via rivers and estuaries, are positively correlated within many coastal systems around the world (Nixon et al., 1986; Caddy, 1993; Houde and Rutherford, 1993). The coupling of physics and biogeochemistry occurs at many spatial scales in estuaries (figure 1.1; Geyer et al., 2000). Estuarine circulation, river and groundwater discharge, tidal flooding, resuspension events, and exchange flow with adjacent marsh systems (Leonard and Luther, 1995) all constitute important physical variables that exert some level of control on estuarine biogeochemical cycles. There has been considerable debate about the definition of an estuary because of the divergent properties found within and among estuaries from different regions of the world. Consequently, there have been numerous attempts to develop a comprehensive and universally accepted definition. Pritchard (1967, p. 1) first defined estuaries based on salinity as “semi-enclosed coastal bodies of water that have a free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage.” A general schematic representation of an estuary, as defined by Pritchard (1967), and further modified by Dalrymple et al. (1992) to include more physical and geomorphological processes, is shown in figure 1.2.
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Bethke, Craig M. "Geochemical Kinetics." In Geochemical Reaction Modeling. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195094756.003.0018.
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To this point we have measured reaction progress parametrically in terms of the reaction progress variable ξ, which is dimensionless. When in Chapter 11 we reacted feldspar with water, for example, we tied reaction progress to the amount of feldspar that had reacted and expressed our results along that coordinate. Studying reactions in this way is in many cases perfectly acceptable. But what if we want to know how much time it took to reach a certain point along the reaction path? Or, when modeling the reaction of granite with rainwater, how can we set the relative rates at which the various minerals in the granite dissolve? In such cases, we need to incorporate reaction rate laws from the field of geochemical kinetics. The differences between the study of thermodynamics and kinetics might be illustrated (e.g., Lasaga, 198la) by the analogy of rainfall on a mountain. On the mountaintop, the rainwater contains a considerable amount of potential energy. With time, it flows downhill, losing energy (to be precise, losing hydraulic potential, the mechanical energy content of a unit mass of water; Hubbert, 1940), until it eventually reaches the ocean, its lowest possible energy level. The thermodynamic interpretation of the process is obvious: the water seeks to minimize its energy content. But how long will it take for the rainfall to reach the ocean? The rain might enter a swift mountain stream, flow into a river, and soon reach the sea. It might infiltrate the subsurface and migrate slowly through deep aquifers until it discharges in a distant valley, thousands of years later. Or, perhaps it will find a faster route through a fracture network or flow through an open drill hole. There are many pathways, just as there are many mechanisms by which a chemical reaction can proceed. Clearly, the questions addressed by geochemical kinetics are more difficult to answer than are those posed in thermodynamics. In geochemical kinetics, the rates at which reactions proceed are given (in units such as moles/sec or moles/yr) by rate laws, as discussed in the next section. Kinetic theory can be applied to study reactions among the species in solution.
Conference papers on the topic "Deep water flow; Ocean; Seawater"
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Haraldsen, Kristian. "Unique Long Term Simulated Service Testing of Selected Deep Water Wet Insulation Coating Systems." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10630.
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The oil and gas industry is moving to deeper water developments and thermal insulation of pipelines at 2–3000 meter water depths is required. Wet thermal insulation systems are exposed directly to the seawater and large hydrostatic water pressure in combination with high fluid temperatures challenge the integrity of the insulation systems. The thermal insulation properties of the insulation system can be gradually decreased by thermal and physical strains and challenge the flow assurance if not taken into account in the design. Wet thermal insulation systems have traditionally been qualified for long term use by a combination of long-term small scale aging tests and shorter term full scale simulated service tests (typically 7–28 days). To evaluate the long performance, simulated service tests have been run for one full year at high water pressure and internal pipe temperatures. A selection of commercially available wet insulation systems have been tested together with system specific field joint coatings under the maximum internal pipe temperature specified for the individual coating systems. The test has been run in natural seawater at 300 barg pressure and temperature of 2–4 °C. The coating thicknesses have been selected to give U-values of 3–4 W/(m2K). Before the simulated service testing all test pipes were run through a simulated reel installation to impose realistic strains on the coating systems before testing. All tested coatings performed according to expectations during the simulated service test. The syntactic systems (PP and PU based) gave gradual decrease in thermal insulation efficiency with time but the reduction was close to linear and can be accounted for in the design. The coating systems based on solid polymer materials did not show the same reduction of thermal insulation properties with time. Tests of natural cool-down performance of the insulated test pipes showed that the cool down times were maintained during the one year simulated service tests. Post-test investigations of the insulation materials did not reveal significant degradation of the materials as result of the tests but coating systems application related defects were identified which had developed over the test period. None of the pre-existing defects developed to such an extent as to affect the overall U-value of the coating system.
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Xiang, Sherry, Peimin Cao, Jingxi He, Steve Kibbee, and Sean Bian. "Water Intake Riser Model Test and Numerical Calibration." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-42248.
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A model test campaign of a large diameter water intake riser (WIR) has been planned, designed, and successfully executed in an offshore model basin. The objective of the model test is to better understand the global dynamic behavior of WIR, and thus advance its design. The scopes of the model test are to measure the response of the riser under floater motions; investigate the effect of the internal water and flow rate; and observe any vortex-induced-vibration (VIV) and axial instability due to motion and / or internal flow. The paper presents the model test results and the numerical calibrations and validations. The WIR pipe was carefully scaled and designed to meet the test objectives. The WIR in model test scale is 150 mm in inside diameter and approximately 36 m in length. The model test setup includes a fully instrumented riser, a planar motion mechanism (PMM) which simulates the vessel motion and an internal water flow system (IWFS). The riser was instrumented with Fiber Bragg Grating (FBG) strain sensors along the pipe length and circumference. The WIR was hung-off from the PMM inside the deep basin pit. More than 200 cases were carried out in the basin including the sinusoidal motion tests and random motion tests with different flow rates. The model tests collected a wealth of data of the WIR dynamic responses under the vessel motions and the internal water flow conditions. As expected, WIR global bending responses are highly dependent on the pipe excitation modes and their corresponding mode curvatures. These responses can be predicted well by numerical software through a calibration process. The axial response of WIR due to motion and/or internal flow is much more complex. The amount of internal water coupled with the pipe depends on the vessel motions and internal flow fluctuation. This is important for axial stability prediction and seawater lift system design.
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Udegbunam, John Emeka, Dan Sui, Fatemeh Moeinikia, Antonio C. V. M. Lage, Kjell Kåre Fjelde, Øystein Arild, Herimonja A. Rabenjafimanantsoa, and Gerhard H. Nygaard. "A Transient Flow Model for Predicting Pressure Buildup in Closed Annuli." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61209.
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The annuli between two casings can be closed or open to formation. After completion, the temperature of the annular fluids will be close to the formation temperature. This is because it will take some time for the well to begin to exchange heat with the produced fluids from the reservoir. If the well is located in deep water, the wellhead temperature will be equal to the bottom seawater temperature. At the start of production, warm reservoir fluids will be transported upward to the surface. This will transport heat to the upper part of the well and heat up fluids in the closed annuli. Because of the space limitation, the fluids are not allowed to expand. As a result, the pressure in each annulus will build up with time. In the worst case, this can lead to casing failures. A similar situation may occur when a high pressure, high temperature (HPHT) well is shut in and the well temperature approaches the formation temperature. If there is a net heating of the well, a pressure buildup will be exerted on the blowout preventer (BOP) system. An example well consists of several casings and producing tubing. Each annulus is filled with a fluid, which can be a water-based or an oil-based fluid. In this study, a simple fluid, which comprises water and barite with no additives, is considered. The monodisperse suspension will be used to investigate the barite settling in a closed A-annulus. It is expected that the settling process will be much faster than it would have been if the fluid is a gel. The production casing and packers serve as barrier elements in the well. This paper gives an overview and challenges associated with temperature-induced pressure increase in closed annuli. The paper also considers barite settling — another effect responsible for annular pressure buildup (APB) in closed annuli. In addition, remedies for APB will be reviewed. The dynamic density and volume behavior of a fluid depend on pressure and temperature. To predict APB, a transient flow model is required. The main objective is to demonstrate that the AUSMV scheme can simulate APB due to barite settling and temperature increase. The AUSMV is a hybrid explicit numerical scheme that combines advection upstream splitting method (AUSM) and flux vector splitting (FVS) method. A transient hydraulic model should be able to capture the dynamics of the settling process where settling particles force compressible liquid upward, resulting in pressure buildup in a sealed annular space. The proposed model captures these effects and takes the compressibility of the annular fluid into account. Another advantage of the transient model is that it can also predict the local concentration of barite in the annulus. This is important for a closer integration of the scheme with a temperature model, because heat flux depends on the spatial and time-varying compositions of the fluid in the annulus. The AUMSV scheme is one out of many numerical methods that can be used for solving mass transport problems. It has been chosen due to its simplicity with respect to implementation. In the present work, the annular temperatures predicted by a separate transient temperature model will serve as inputs to the numerical scheme.
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Wayne Turner, M., John G. Cleland, and John Baker. "Seawater Activated Power System (SWAPS): Energy for Deep Water Detection, ocean platforms, buoys, surface craft and submersibles." In OCEANS 2011. IEEE, 2011. http://dx.doi.org/10.23919/oceans.2011.6107018.
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Ding, Qian, Baojiang Sun, Zhiyuan Wang, Yonghai Gao, Yu Gao, Yongqiang Liao, Di Wang, and Andi Xia. "Rheological Properties of Water-Based Drilling Fluids in Deep Offshore Conditions." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-96719.
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Abstract In deep-water drilling, the drilling fluid is affected by the alternating temperature field derived from the low temperature of the seawater and the high temperature of the formation. The complicated wellbore temperature and pressure environments make the prediction of rheological properties of the drilling fluid difficult. In this study, the rheological properties of water-based drilling fluid in full temperature and pressure range of deep-water conditions were tested from 2 to 150 °C (35.6 to 302 °F) and 0.1 to 70 MPa (14.5 to 10000psi). The experiment was carried out by the OFI130-77 high temperature and high pressure rheometer. The experimental data were processed by multiple regression analysis method, and the mathematical model for predicting the apparent viscosity, plastic viscosity and yield point of water-based drilling fluid under high temperature and high pressure conditions was established. The experimental results show that when the temperature is lower than 65 °C (149 °F), the apparent viscosity and plastic viscosity of the water-based drilling fluid decrease significantly with increasing temperature. When the temperature is higher than 65 °C (149 °F), the apparent viscosity and plastic viscosity decrease slowly. Under low temperature conditions, the effect of pressure on the apparent viscosity and plastic viscosity of water-based drilling fluids is relatively significant. The calculated values of the prediction model have a good agreement with the experimental measurements. Compared with the traditional model, this prediction model has a significant improvement in the prediction accuracy in the low temperature section, which can provide a calculation basis for on-site application of deepwater drilling fluid.
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Zhao, Jian, Zhimin Tan, and Terry Sheldrake. "Deep Water Carcass Development: Effects of Carcass Profile on Collapse Resistance." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11321.
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The increasing application of flexible pipes in deep water requires extension of the product’s capability through higher design pressures with large diameters, while one of the most important structural capacities is collapse resistance. In addition to the introduction of new materials and manufacturing capability, the carcass structure is also expected to be optimized for maximum purpose. The carcass is an interlocked metallic construction that is used as the innermost layer to prevent for example, either totally or partially, the collapse of the internal pressure sheath due to decompression, or the pipe, due to external hydrostatic pressure, tensile armour pressure, and mechanical crushing loads. During manufacture of the carcass, its profile may differ from the nominal designed profiles and this may affect the collapse resistance. In this paper the effects of the carcass profile on the wet collapse strength of flexible pipes via numerical simulation are investigated. The wet collapse strength is referred to as the hydrostatic collapse strength of the pipe when the annulus is assumed to be flooded with seawater. In this condition, the external hydrostatic pressure acts directly on the barrier layer above the carcass. Using ANSYS, a 3D finite element model with the consideration of helical effects and cyclic boundary condition, which was developed to check the effect of each part of the carcass profile on the collapse strength by varying the design parameters, e.g. inclination angles, etc, and manufacturing ovality. As both verification and comparison, the principle of the effects is explored and explained analytically. The results can be used as an acceptance criterion on the as-built profiles in the manufacturing process, and as a guideline for the innovation and optimization of the carcass for maximum performance.
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Giraldo, Diego Garcia, and Ronald W. Yeung. "The Deep-Water-Horizon Spill: Flow-Rate Estimation Based on Satellite Images." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-84153.
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The “Deep Water Horizon” Mobil Offshore Drilling Unit (MODU) is one of several classes of floatable drilling machines. As a consequence of the accident on April 20, 2010, the worst ecological disaster with regard to oil spills in the US history was generated in the Gulf of Mexico, causing extensive damage to marine and wildlife habitats, as well as the Gulf’s fishing and tourism industries. Since that moment, experts are trying to estimate the total amount of oil being lost into the sea. The objective of this presentation is to report a procedure developed in the first author’s thesis1 an independent and logical estimate of the oil flow rate into the Gulf of Mexico produced by the rupture in this rig. There are a number of possible approaches to estimate the flow rate of oil spilling into the Gulf of Mexico. The Plume Modeling Team has developed an approach by observing video image of the oil/gas mixture escaping from the kinks in the riser and the end of the riser pipe. The Mass Balance Team has developed a range of values using USGS (US Geological Survey) and NOAA (National Oceanic and Atmospheric Administration) data analysis collected from NASA’s (National Aeronautics and Space Administration) Airborne Visible InfraRed Imaging Spectrometer (AVIRIS). Finally, a reality-check estimate was based on the amount of oil collected by the Riser Insertion Tube Tool (RITT) plus the estimate of how much oil is escaping from the RITT, and from the kink in the riser. However, there are several limitations in each of these techniques.
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Gotoh, Koji, Tetsuya Ueda, Koji Murakami, and Tomoaki Utsunomiya. "Wear Performance of Mooring Chain in Wet Environment With Substitute Ocean Water." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95822.
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Abstract Floating wind turbine facilities installed in deep sea areas play an essential role in the promotion of green energy. One of the problems associated with the commercialization of facilities installed in the deep sea is the maintenance cost of mooring chains, because they are expensive and wear between links leads to chain breakage. Therefore, it is necessary to establish a quantitative wear evaluation method for mooring chains. An experimental facility to reproduce the wear caused by sliding between links at the scale of an actual floating wind turbine was developed to investigate the wear performance in seawater conditions, and wear tests were conducted. Substitute ocean water was applied to the experiment instead of seawater. In addition, a procedure for nonlinear finite element analysis was improved to estimate the behaviour of wear between links. Measured stress versus strain relations of the links was considered in the finite element analysis. The experiments and numerical analysis confirmed that the amount of wear in the substitute ocean water was less than that obtained in dry air and that the tensile force between links is an important factor for the degree of wear between links.
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Hasan, A. Rashid, Rayhana N. Sohel, and Xiaowei Wang. "Estimating Zonal Flow Contributions in Deep Water Assets From Pressure and Temperature Data." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62537.
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Producing hydrocarbon from deep water assets is extremely challenging and expensive. A good estimate of rates from multiple pay zones is essential for well monitoring, surveillance, and workover decisions. Such information can be gleaned from flowing fluid pressure and temperature; deep-water wells are often well instrumented that offers such data on a continuous basis. In this study a model is presented that estimates zonal flow contributions based on energy and momentum balances. Kinetic and heat energy coming from the reservoir fluid to the production tubing is accounted for in the model. The momentum balance for wellbore takes into account differing flow profile in laminar and turbulent flows. In addition, when sandface temperature data are not available, a recently developed analytical model to estimate the effect of Joule-Thompson expansion on sandface temperature was used to estimate sandface temperature from reservoir temperature. The model developed can be applied to any reservoir with multiple pay zones and is especially useful for deep-water assets where production logging is practically impossible. Available field data for multiphase flow was used to validate the model. Sensitivity analyses were performed that showed accurate temperature data is essential for the model to estimate zonal contribution accurately.
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Liu, Depeng, Shangmao Ai, and Liping Sun. "Dynamic Modelling of Deep-Water Riser With Slug Flow Based on ALE-ANCF." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18109.
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Abstract The internal flow in gas-liquid mixing riser often displays a flow pattern known as slug flow, in which gas and liquid are alternately distributed. Dynamic effects due to slug flow is normally most obvious in areas along the riser with high curvature, which is caused by the centrifugal load component. The global riser response to this excitation can be predicted by nonlinear time domain analysis using the load model as described for slug flow conditions. In this study, the riser with internal slug flow is modeled under the framework of Arbitrary-Lagrange-Euler (ALE) description by using the Absolute Node Coordinate Formula (ANCF). The riser is discretized into ANCF cable element based on the Euler-Bernoulli beam assumption, while one-dimensional moving medium modeling method with time-varying density is used to model slug element. Compared with other FEA models of riser subjected to internal flow, the ALE-ANCF model allow easily modeling of complex mass flow and has the advantages of high speed and high precision in handling large deformation of riser, especially for the compliant riser configurations. Numerical simulations of two simplified models are carried out to validate the developed model, then the dynamic response such as displacement, tension force and bending moment of the riser conveying slug flow are analyzed.
Reports on the topic "Deep water flow; Ocean; Seawater"
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Beck, Aaron. RiverOceanPlastic: Land-ocean transfer of plastic debris in the North Atlantic, Cruise No. AL534/2, 05 March – 26 March 2020, Malaga (Spain) – Kiel (Germany). GEOMAR Helmholtz Centre for Ocean Research Kiel, 2020. http://dx.doi.org/10.3289/cr_al534-2.
Full textAbstract:
Cruise AL534/2 is part of a multi-disciplinary research initiative as part of the JPI Oceans project HOTMIC and sought to investigate the origin, transport and fate of plastic debris from estuaries to the oceanic garbage patches. The main focus of the cruise was on the horizontal transfer of plastic debris from major European rivers into shelf regions and on the processes that mediate this transport. Stations were originally chosen to target the outflows of major European rivers along the western Europe coast between Malaga (Spain) and Kiel (Germany), although some modifications were made in response to inclement weather. In total, 16 stations were sampled along the cruise track. The sampling scheme was similar for most stations, and included: 1) a CTD cast to collect water column salinity and temperature profiles, and discrete samples between surface and seafloor, 2) sediment sampling with Van Veen grab and mini-multi corer (mini-MUC), 3) suspended particle and plankton sampling using a towed Bongo net and vertical WP3 net, and 4) surface neusten sampling using a catamaran trawl. At a subset of stations with deep water, suspended particles were collected using in situ pumps deployed on a cable. During transit between stations, surface water samples were collected from the ship’s underway seawater supply, and during calm weather, floating litter was counted by visual survey teams. The samples and data collected on cruise AL534/2 will be used to determine the: (1) abundance of plastic debris in surface waters, as well as the composition of polymer types, originating in major European estuaries and transported through coastal waters, (2) abundance and composition of microplastics (MP) in the water column at different depths from the sea surface to the seafloor including the sediment, (3) abundance and composition of plastic debris in pelagic and benthic organisms (invertebrates), (4) abundance and identity of biofoulers (bacteria, protozoans and metazoans) on the surface of plastic debris from different water depths, (5) identification of chemical compounds (“additives”) in the plastic debris and in water samples.