Дисертації: "Technology Oceania"

1

Waugh, Daniel. "Oceania Football Confederation the impact of affiliate disaffiliation on the inter-organizational dynamics of a federated network : a dissertation submitted to Auckland University of Technology in partial fulfilment of the requirements for the degree of Master of Business (MBus), 2009 /." Click here to access this resource online, 2009. http://hdl.handle.net/10292/796.

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2

Nishiyama, Takashi. "Swords into plowshares civilian application of wartime military technology in modern Japan, 1945-1964 /." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1104324814.

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Анотація:

Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xiv, 246 p.; also includes graphics (some col.) Includes bibliographical references (p. 212-242).

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3

Kim, Edward H. 1974. "Advanced satellite communication technology for oceanic air traffic control." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47526.

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4

Anders, Signahl, and Hjerpe Nils. "Deep Green i oceana strömmar - en konceptstudie." Thesis, Linköping University, Machine Design, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57829.

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With growing economies and better living standards in many parts of the world today, there is a need of expanding the capacity of generating electricity. The alternatives for renewable energy technologies are not fully developed and have still some problems to conquer.

The company Minesto has developed a technology that is called Deep Green. It is designed to gain electricity from tidal currents. Deep Green works in a similar way as a kite that is attached to the seafloor with a moving wire. It contains of a wing that moves due to the water current. The path of the movement is circular or a shape of an “8”. The turbine under the wing is powered by the water flow which in turn leads to generation of electricity by the generator.

The purpose of this thesis is to investigate the potential of using the Deep Green technology in ocean currents with respect to construction and economy. The site for the investigation is off the east coast of Florida where the Florida current streams with a speed of about 1, 5 m/s close to the surface. The major difference compared to the use in tidal currents is the deep waters of about 300 m and a oneway current direction.

A mooring construction was developed and optimized and with the use of carbon fiber ropes, buoys and foundations lets 9 Deep Greens operate between 20 and 79 m depth. The idea is to install 7 such clusters with a total of 63 Deep Greens on the site in Florida. This configuration generates a power of 24 MW and gives a production of 185 GWh/year.

Economic accounts were made with support of earlier made calculations regarding a park of 60 Deep Greens in a tidal current application. The results for the clustered configuration in ocean currents indicated a cost of 0,67 SEK/kWh with a discount rate of 8%. The required capital for the installation is about 780 mSEK (CAPEX). The operating costs (OPEX) are 43,3 mSEK.

The design seems reasonable in many respects and it operates in a continuous ocean current with good electricity generation. The use of Deep Green in ocean currents speaks for being a profitable application. Though, it will be a large‐scale economic project, mainly because installations in a small scale will not be profitable due to costs such as grid connection.

Critical issues to look at in a further development was considered to be surveys of the installation site, the displacement and movements of the mooring, the buoyancy‐system and the installation procedure.

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5

Petrakakos, Nikolaos Harilaos. "Port security and information technology." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33573.

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Анотація:

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2005.
Includes bibliographical references (p. 92).
The terrorist attacks of September 11th 2001 on New York and Washington DC shed light on the many security shortcomings that sea ports and the entire import and export process face. A primary source of these problems is the information sharing process which makes it hard to track the source of a problem in the import and export process due to lack of information and coordination. This thesis attempts to examine these data sharing problems by looking at what federal agencies, ports, and other private firms have been doing to solve the problems. The document exchange between various stakeholders and the process behind that was also examined to find potential problems. The reason behind doing this is because it is essential to understand the process and its problems before any meaningful results can be extracted from examining the efforts being done to solve the problems. The findings were similar for all cases showing that the primary reason preventing any of these problems to be solved is the unwillingness of commercial stakeholders to share information due to lack of incentives and privacy concerns.
by Nikolaos Harilaos Petrakakos.
S.M.

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6

Ryan, Andrea Catherine 1968. "Should we fertilize the oceans? : examining the science, economics and policy of the iron hypothesis & ocean fertilization." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9604.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and, (S.M.)--Massachusetts Institute of Technology, Technology and Policy Program, 1998.
Includes bibliographical references.
John Martin's 'iron hypothesis' (Martin, 1990), and the subsequent ground-breaking IRONEX experiments (Martin 1994, Coale 1996) have stimulated wide spread speculation about the concept of fertilizing the oceans. It has been suggested that adding nutrients to the open oceans will stimulate primary production, increasing the sequestration of carbon dioxide and enhancing potential fish harvest. Ocean fertilization has thus been heralded as a possible cure for global climate change and world food shortages. Despite considerable scientific effort, private investment, and public interest in this field there has been limited evaluation of the feasibility of ocean fertilization. This thesis attempts to fill this void by addressing not only the scientific, but also the economic and policy dimensions of ocean fertilization. It starts by reviewing current research proposals and implementation activities in the field of ocean fertilization. It identifies potential environmental impacts and biogeochemical consequences of ocean fertilization, highlighting the outstanding scientific unknowns associated with this field. The study reviews cost estimates compiled by the private sector, and examines likely practical obstacles to implementation. Legal, political and public response to fertilization proposals is also explored. Finally, some of the ethical concerns relating to fertilizing the oceans are discussed, and recommendations on future research directions and initiatives to manage this rapidly growing field are provided.
by Andrea Catherine Ryan.
S.M.

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7

Kleiman, Alexander B. (Alexander Bjørn) 1973. "The application of Automatic Identification Technology onboard naval and commercial ships." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/91347.

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8

Stromgren, Chel 1969. "The use of automatic identification technology to improve shipyard material handling processes." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/88352.

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9

Psallidas, Konstantinos 1973. "Forecasting the system-level impact of technology infusion on conventional submarine design." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/91799.

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Анотація:

Thesis (S.M. in Ocean Systems Management; and, Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2003.
Includes bibliographical references (leaves 105-107).
by Konstantinos Psallidas.
S.M.in Ocean Systems Management; and, Nav.E.

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10

Barlin, Matthew V. (Matthew Victor) 1975. "Implementing automatic identification technology to improve the construction of naval and commercial ships." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/91352.

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11

Dunlap, Gary H. (Gary Holt) 1961. "Applied information technology (IT) for ship design, production and lifecycle support : a total systems approach." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80194.

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Анотація:

Thesis (S.M. in Naval Construction and Engineering)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and (S.M. in Ocean Systems Management)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999.
Includes bibliographical references (leaves 108-110).
by Gary H. Dunlap.
S.M.in Ocean Systems Management
S.M.in Naval Construction and Engineering

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12

Larson, Parker E. (Parker Edward) 1979. "The technology and economic feasibility of offshore liquefied natural gas receiving terminals in the United States." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/91797.

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Анотація:

Thesis (S.M. in Ocean Systems Management)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2003.
Includes bibliographical references (p. 96-102).
by Parker E. Larson.
S.M.in Ocean Systems Management

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13

Glanvill, Sarah Jane Marie. "Atmospheric corrosion of AA2024 in ocean water environments." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8554/.

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Observations of atmospheric corrosion on aluminium alloy AA2024-T3 were made within droplets of NaCl solution and simulated ASTM ocean water. High speed in-situ synchrotron X-ray tomography has been used to observe the initiation and propagation of corrosion sites. Tomographic scans had a temporal resolution of 300s per full tomographic scan, providing a non-destructive visualisation of corrosion. Sites initiate at numerous surface morphologies, including at intermetallic inclusions, under surface deposits and salt crystals, and also at sites with no obvious micron-scale microstructural features. It was observed that corrosion sites grow discontinuously and inhomogeneously when conditions are constant, consistent with bursts of dissolution followed by some repassivation. The nature of corrosion products was investigated with Raman spectroscopy and EDX. The dominant corrosion product was Dawsonite for both droplet solutions, however the distribution of corrosion products differed between the two types of droplet. NaCl droplets spread more, resulting in fewer, larger corrosion sites. ASTM ocean water droplets showed multiple small corrosion sites within the droplet owing to the presence of Hydrotalcite around the droplet perimeter. Corrosion development under wet-dry cycling conditions was different for NaCl and ASTM ocean water droplets. Under NaCl droplets, no growth or initiation was observed during “dry” phases. However, ASTM ocean water remains partially wet in “dry” periods as some of the salt constituents in ASTM ocean water remain hydrated. As a consequence, corrosion site growth is able to continue.

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14

Murphy, Brian P. (Brian Patrick) 1963. "Machinery monitoring technology design methodology for determining the information and sensors required for reduced manning of ships." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/88345.

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Анотація:

Thesis (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.
Includes bibliographical references (p. 115-116).
by Brian P. Murphy.
Nav.E.
S.M.

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15

Ito, Takamitsu 1976. "The biogeochemistry and residual mean circulation of the southern ocean." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30290.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2005.
Includes bibliographical references (p. 233-244).
I develop conceptual models of the biogeochemistry and physical circulation of the Southern Ocean in order to study the air-sea fluxes of trace gases and biological productivity and their potential changes over glacial-interglacial timescales. Mesoscale eddy transfers play a dominant role in the dynamical and tracer balances in the Antarctic Circumpolar Current, and the transport of tracers is driven by the residual mean circulation which is the net effect of the Eulerian mean circulation and the eddy-induced circulation. Using an idealized, zonally averaged model of the ACC, I illustrate the sensitivity of the uptake of transient tracers including CFC11, bomb-[Delta]¹⁴C and anthropogenic CO₂ to surface wind stress and buoyancy fluxes over the Southern Ocean. The model qualitatively reproduces observed distribution of CFC11 and bomb-[Delta]¹⁴C , and a suite of sensitivity experiments illustrate the physical processes controlling the rates of the oceanic uptake of these tracers. The sensitivities of the uptake of CFC11 and bomb-[Delta]¹⁴C are largely different because of the differences in their air-sea equilibration timescales. The uptake of CFC11 is mainly determined by the rates of physical transport in the ocean, and that of bomb-[Delta]¹⁴C is mainly controlled by the air-sea gas transfer velocity. Anthropogenic CO₂ falls in between these two cases, and the rate of anthropogenic CO₂ uptake is affected by both processes. Biological productivity in the Southern Ocean is characterized with the circum- polar belt of elevated biological productivity, "Antarctic Circumpolar Productivity Belt".
(cont.) Annually and zonally averaged export of biogenic silica is estimated by fitting the zonally averaged tracer transport model to the climatology of silicic acid using the method of least squares. The pattern of export production inferred from the inverse calculation is qualitatively consistent with recent observations. The pattern of inferred export production has a maximum on the southern flank of the ACC. The advective transport by the residual mean circulation is the key process in the vertical supply of silicic acid to the euphotic layer where photosynthesis occurs. In order to illustrate what sets the position of the productivity belt, I examined simulated biological production in a physical-biogeochemical model which includes an explicit ecosystem model coupled to the phosphate, silica and iron cycle. Simulated patterns of surface nutrients and biological productivity suggest that the circumpolar belt of elevated biological productivity should coincide with the regime transition between the iron-limited Antarctic zone and the macro-nutrients limited Subantarctic zone. At the transition, organisms have relatively good access to both micro and macro-nutrients. Kohfeld (in Bopp et al.; 2003) suggested that there is a distinct, dipole pattern in the paleo-proxy of biological export in the Southern Ocean at the LGM. I hypothesize that observed paleo-productivity proxies reflect the changes in the position of the Antarctic Circumpolar Productivity Belt over glacial-interglacial timescales. Increased dust deposition during ice ages is unlikely to explain the equatorward shift in the position of the productivity belt due to the expansion of the oligotrophic region and the poleward shift of the transition between the iron-limited regime and the macro-nutrient limited regime.
(cont.) I develop a simple dynamical model to evaluate the sensitivity of the meridional overturning circulation to the surface wind stress and the stratification. The theory suggest that stronger surface wind stress could intensify the surface residual flow and perturb the position of the productivity belt in the same sign as indicated by the paleo-productivity proxies. Finally, I examined the relationship between the surface macro-nutrients in the polar Southern Ocean and the atmospheric pCO₂. Simple box models developed in 1980s suggests that depleting surface macro-nutrients in high latitudes can explain the glacial pCO₂ drawdown inferred from polar ice cores. A suite of sensitivity experiments are carried out with an ocean-atmosphere carbon cycle model with a wide range of the rate of nutrient uptake in the surface ocean. These experiments suggest that the ocean carbon cycle is unlikely to approach the theoretical limit where "pre- formed" nutrient is completely depleted due to the dynamics of deep water formation. The rapid vertical mixing timescales of convection preclude the ventilation of strongly nutrient depleted waters. Thus it is difficult to completely deplete the "preformed" nutrients in the Southern Ocean even in a climate with elevated dust deposition in the region, suggesting some other mechanisms for the cause of lowered glacial pCO₂.
by Takamitsu Ito.
Ph.D.

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16

Sarmah, Biki. "Optimisation of Electromechanical Drivetrain for Wave Energy Converter at CorPower Ocean AB." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234838.

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The potential of wave energy has been constantly explored in past couple of years. The contribution from the CorPower Ocean AB towards the development of wave energy is important. This thesis involves the detailed study of current ½ scale (1:2) model of a Wave Energy converter (WEC) and computing the results to find the optimised component ratings. The primary goal of the thesis is to optimise each component of the electro-mechanical drivetrain with the assistance of modelling software Simulink and Matlab. In the initial stage of this thesis the generator and drive component are analysed without changing the drivetrain configuration of the WEC. A method is established to find suitable ratings of generator and drive system for the WEC which provides high system efficiency and power output. The method is developed in such a way that it can be implemented for any scale model whether it is full-scale or half-scale. Once finding the optimised ratings of generator and drive combination, different configuration of the drivetrain is explored for the WEC. The influence of drivetrain mechanism with and without flywheel is also considered and compared with the ½ scale model. The drivetrain configurations comprise of single generator, double generator and quadruple generator alignment with the WEC. All configurations of the generator are compared with and without a flywheel in the drivetrain. The benefit of including a flywheel involves power smoothing, control simplification and reducing component volume, whereas the benefit of not including flywheel includes better hydrodynamic damping and control. The outcome of the results showcase that the existing ½ scale WEC model can provide better performance when the generator ratings are reduced because of low speed at small sea state. The speed-ratio of the gearbox can either be increased or a new system can be introduced which chooses the generator rating depending on the sea state and motion profile. Based on the analysis result of an optimised ½ scale model, the full scale drivetrain component ratings are introduced with a different drivetrain topology. Results from the Full scale WEC model showcase that a double generator WEC configuration without a flywheel is a reliable and efficient solution for CorPower Ocean AB.

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17

Schneider, Bettina. "Economic feasibility study for the wave energy technology of Gaia Power Group Pty Ltd." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/79331.

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Thesis (MBA)--Stellenbosch University, 2011.
Gaia Power is a South African start-up in the renewable energy industry. Among other products, they developed a wave energy converter, which is a device used to extract energy from ocean waves. This research deals with the economic feasibility study of the wave energy converter. Wave energy is a young field of research, especially in the South African context. Therefore sources for multiple angles of the project had to be found, analysed and brought into the Gaia Power context. Understanding the cost drivers of a wave energy plant was the foundation of the research itself. The Gaia Power specific levelised cost of electricity generation was calculated based on actual supplier quotes, reference costs found in the literature as well as assumptions. Still, such a calculation is actually more an estimation due to a high uncertainty level in all cost components. Especially the construction cost as well as the discount rate used have therefore been tested for sensitivity. Gaia Power‟s target production cost was R0.54 kWh, which equalled the Eskom tariff at the time of this research. Taking into account a R0.10/kWh fee payable to Eskom, the target cost sank to R0.44, which is about 25 percent lower than the minimum value for electricity generation cost found in the literature. This target was therefore expected to be and proved to be difficult to reach. The calculated levelised electricity cost was R0.99/kWh, with a possible range of R0.54/kWh to R1.60/kWh observed in the sensitivity analysis. These results show that the Gaia Power wave energy converter in the given specifications was not economically feasible. It was therefore recommended to rethink the specifications in order to reduce construction cost, which proved to be the largest cost driver. Besides the quantitative findings, this research also has a strong qualitative side. During the whole research it became obvious that there was an overall high risk level in the project due to the lack of experience with wave energy in general and in South Africa specifically, as well as the high impact of weather on the construction. Those risks were identified, analysed and recommended mitigation actions were derived.

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18

Lijefors, Carl, and Adrian Stenbäck. "Dynamics of non-spherical particles in vortices : Accumulation of plastics in the ocean." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297797.

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Today the plastic waste has made itself a permanent part of our marine environment, and have presented itself as a many faced problem. Becauseof this it is of grave importance to focus research on understanding thedynamics and accumulation of these plastic particles in various flows. The focus in this report was to understand and account for the various equations and theories that applies for the plastic particles, and to understand the accumulation of the particles. The particles properties, kinematicsand dynamics was defined, and a 2D Taylor-Green flow was used for the simulations because of its similar characteristics to those flows that can be found in the oceans. With Matlab the position, orientation, velocity and accumulation of the particles could be simulated. The results from the simulations where analysed and showed that for weaker vortex the particles get trapped in the vortices. For the stronger vortices the particles instead moved to regions of downward velocity, this behaviour was confirmed in Niazi Ardekani et al. 2017.

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19

Israelsson, Peter H. (Peter Hampus) 1973. "Evaluation of the environmental viability of direct injection schemes for ocean carbon sequestration." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43163.

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Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2008.
Includes bibliographical references (p. 143-159).
This thesis evaluates the expected impact of several promising schemes for ocean carbon sequestration by direct injection of CO2, and serves as an update to the assessment by Auerbach et al. (1997) and Caulfield et al. (1997) of water quality impacts and the induced mortality to zooplankton. The present work extends the methodology used in the earlier studies, incorporates recent acute CO2 toxicity data on marine organisms, and considers three revised discharge approaches: a point release of negatively buoyant CO2 hydrate particles from a moving ship; a long, bottom-mounted diffuser discharging buoyant liquid CO2 droplets; and a stationary point release of hydrate particles forming a sinking plume. Results suggest that it is possible with present technology to engineer discharge configurations which achieve sufficient dilution to largely avoid acute impacts. Sub-lethal and ecosystem effects are discussed qualitatively, but not analyzed quantitatively. The analysis suggests that, as a temporary climate change mitigation strategy, ocean carbon sequestration by direct injection should not be dismissed on the basis of environmental impact alone. With minor modification, this thesis will also serve as the final chapter of the author's Ph.D. thesis to be submitted in 2008 to the MIT Department of Civil and Environmental Engineering.
by Peter Hampus Israelsson.
S.M.

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20

Den, Hollander Nikki, and Thorkell V. Thorsteinsson. "A Systematic Approach to Analyze Industrial Clusters : A Case Study of The Iceland Ocean Cluster." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279730.

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Regional industries see a trend of agglomeration of firms in concentrated economic areas. Firms in these regions convene and form a cluster with a wide array of intensive collaborations between the individual actors. The result is the enhancement of a variety of aspects in the region such as innovation, and entrepreneurial activities and attitudes. Research on cluster theory has shoZn an effectiYe Za\ of anal\]ing a cluster¶s strategy and current state by identifying the phase of a cluster in its Cluster Lifecycle. In order to locate a cluster in the Cluster Lifecycle, the characteristics of the cluster need to be mapped and analyzed. Here, a gap in the literature can be found as there is no consensus on a systematic method for the analysis of cluster characteristics. Hence, this paper derives a novel way of analyzing cluster characteristics using the Cluster Canvas. Building on these existing and newly derived methods, the paper answers the research question: What can we learn from this specific cluster by analyzing unique factors in its environment? To create the most complete representation of the phenomenon in its context, the research adopts a single case study method. In the specific case of this thesis a cluster, the Iceland Ocean Cluster (IOC), is used as the case study. Primary data is collected on multiple levels using a survey and semi-structured interviews which are subsequently analyzed qualitatively. All in all, leading to a Cluster Canvas populated with the most significant findings, creating an image of the cluster in its current state of sustainment. Significant conclusions about the state of the cluster relate to its diversity in terms of collaborations and portfolio of firms and how this relates to knowledge diffusion within and outside of the cluster. Finally, evidence shows that the ability of the cluster to adapt and renew strategies over the years has proven fruitful in sustaining its relevance in the industry.
Regionala industrier uppvisar en trend när det gäller koncentration av företag i ekonomiska områden. Företag inom dessa regioner centreras och bildar ett kluster med breda samarbeten företagen emellan. Resultatet blir en förbättring när det gäller flertalet aspekter inom regionen, såsom innovation och entreprenöriella aktiviteter och attityder. Forskning på klusterteori har visat på ett effektivt sätt att analysera ett klusters strategi och nuvarande tillstånd genom att identifiera dess nuvarande fas i klustrets livscykel. För att kunna lokalisera ett kluster i klustrets livscykel måste klustrets karaktäristika mappas och analyseras. Här finns ett gap i litteraturen då det inte råder någon konsensus över hur klusters karaktäristika kan analyseras på ett systematiskt sätt. Denna uppsats utvecklar ett nytt sätt analysera klusters karaktärsdrag genom att använda Cluster Canvas. Baserat på existerande och nyligen utvecklade metoder, svarar uppsatsen på forskningsfrågan: Vad kan vi lära oss från ett specifikt kluster genom att analysera unika faktorer i dess omgivning? För att skapa den mest kompletta representationen av fenomenet i dess kontext, analyseras ett specifikt case. Iceland Ocean Cluster (IOC) är det kluster som studeras i uppsatsen, Primärdata samlas in på flertalet nivåer med hjälp av enkätundersökning samt semi-strukturerade intervjuer, vilka senare analyseras kvalitativt. Vår analys resulterar i ett Cluster Canvas som innehåller de mest signifikanta resultaten och som skapar en bild av klustret i fokus för detta kluster i dess nuvarande form. Våra viktigaste slutsatser om klustrets status relaterar till dess mångfald i termer av samarbete och portföljen av företag, samt hur detta relaterar till kunskapsspridning inom och utanför klustret. Slutligen, visar resultaten att klustrets förmåga att anpassa och förnya strategier över tiden har varit betydelsefullt för att säkerställa dess långsiktiga relevans i branschen.

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21

Wist, Hanne Therese. "Statistical properties of successive ocean wave parameters." Doctoral thesis, Norwegian University of Science and Technology, Norwegian University of Science and Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16.

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For random waves the free surface elevation can be described by a number of individual wave parameters. The main objective of this work has been to study the statistical properties of individual parameters in successive waves; the wave crest height, the wave height and the wave period.

In severe sea states the wave crest heights exhibit a nonlinear behavior, which must be reflected in the models. An existing marginal distribution that uses second order Stokes-type nonlinearity is transformed to a two-dimensional distribution by use of the two–dimensional Rayleigh distribution. This model only includes sum frequency effects. A two-dimensional distribution is also established by transforming a second order model including both sum and different frequency effects. Both models are based on the narrow-band assumption, and the effect of finite water depth is included. A parametric wave crest height distribution proposed by Forristall (2000) has been extended to two dimensions by transformation of the two-dimensional Weibull distribution.

Two successive wave heights are modeled by a Gaussian copula, which is referred to as the Nataf model. Results with two initial distributions for the transformation are presented, the Næss (1985) model and a two-parameter Weibull distribution, where the latter is in best agreement with data. The results are compared with existing models. The Nataf model has also been used for modeling three successive wave heights. Results show that the Nataf transformation of three successive wave heights can be approximated by a first order autoregression model. This means that the distribution of the wave height given the previous wave height is independent of the wave heights prior to the previous wave height. The simulation of successive wave heights can be done directly without simulating the time series of the complete surface elevation.

Successive wave periods are modeled with the Nataf transformation by using a two-parameter Weibull distribution and a generalized Gamma distribution as the initial distribution, where the latter is in best agreement with data. Results for the marginal and two-dimensional distributions are compared with existing models. In practical applications, it is often of interest to consider successive wave periods with corresponding wave heights exceeding a certain threshold. Results show that the distribution for successive wave periods when the corresponding wave heights exceed the root-mean-square value of the wave heights can be approximated by a multivariate Gaussian distribution. When comparing the results with data, a long time series is needed in order to obtain enough data cases. Results for three successive wave periods are also presented.

The models are compared with field data from the Draupner field and the Japan Sea, and with laboratory data from experiments at HR Wallingford. In addition, data from numerical simulations based on second order wave theory, including both sum and frequency effects, are included.

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22

Lambert, Bennett S. (Bennett Spencer). "Observing microbial processes at the microscale with In Situ technology." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122326.

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Анотація:

Thesis: Thesis (Ph. D.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Civil and Environmental Engineering; and the Woods Hole Oceanographic Institution), 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 126-137).
Although seawater appears uniform at scales that humans often interact with and sample, the world that marine microbes inhabit can be highly heterogeneous, with numerous biological and physical processes giving rise to resource hotspots where nutrient concentrations exceed background levels by orders of magnitude. While the impact of this microscale heterogeneity has been investigated in the laboratory with microbial isolates and theoretical models, microbial ecologists have lacked adequate tools to interrogate microscale processes directly in the natural environment. Within this thesis I introduce three new technologies that enable interrogation of microbial processes at the microscale in natural marine communities. The IFCB-Sorter acquires images and sorts individual phytoplankton cells, directly from seawater, allowing studies exploring connections between the diversity of forms present in the plankton and genetic variability at the single-cell level.
The In Situ Chemotaxis Assay (ISCA) is a field-going microfluidic device designed to probe the distribution and role of motility behavior among microbes in aquatic environments. By creating microscale hotspots that simulate naturally occurring ones, the ISCA makes it possible to examine the role of microbial chemotaxis in resource acquisition, phytoplankton-bacteria interactions, and host-symbiont systems. Finally, the Millifluidic In Situ Enrichment (MISE) is an instrument that enables the study of rapid shifts in gene expression that permit microbial communities to exploit chemical hotspots in the ocean. The MISE subjects natural microbial communities to a chemical amendment and preserves their RNA in a minute-scale time series.
Leveraging an array of milliliter-volume wells, the MISE allows comparison of community gene expression in response to a chemical stimulus to that of a control, enabling elucidation of the strategies employed by marine microbes to survive and thrive in fluctuating environments. Together, this suite of instruments enables culture-independent examination of microbial life at the microscale and will empower microbial ecologists to develop a more holistic understanding of how interactions at the scale of individual microbes impact processes in marine ecosystems at a global scale.
by Bennett S. Lambert.
Thesis (Ph. D.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Civil and Environmental Engineering; and the Woods Hole Oceanographic Institution)
Thesis(Ph.D.)--JointPrograminAppliedOceanScienceandEngineering(MassachusettsInstituteofTechnology,DepartmentofCivilandEnvironmentalEngineering;andtheWoodsHoleOceanographicInstitution)

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23

Arabindan-Kesson, Anna Evangeline. "Threads of empire| The visual economy of the cotton trade in the Atlantic ocean world, 1840-1900." Thesis, Yale University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3580726.

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This dissertation examines the art and material culture of the Anglo-American cotton trade in the nineteenth century to consider how these transnational processes influenced different modes of production: artistic, industrial and textile. The Anglo-American cotton trade's importance in the nineteenth century rested on the Atlantic slave trade and its aftereffects. Therefore this study foregrounds the centrality of African American history and culture to the trade's structures of exchange, encounter and transmission as they inflected nineteenth-century British and American artistic production and industrial expansion. In four chapters beginning in 1840 and ending at the beginning of the twentieth century, I juxtapose the work of contemporary artists with historical case studies. I argue that these contemporary artists – Leonardo Drew, Lubaina Himid and Yinka Shonibare – offer new interpretive frameworks for approaching the transactional and transnational contexts of nineteenth-century British, American and African American art and material culture.

Chapter one focuses on the relationship between plantations in the American South and New England, using prints, paintings and textiles that reveal the plantation and factory to be connected landscape. I trace how cotton's movement shaped constructions around place, and materialized connections between communities of labor in antebellum America. Chapter two opens with Lubaina Himid's Cotton.com (2002) and expands the historical relationship of plantation and factory out across the Atlantic. Centralizing Eyre Crowe's Slaves Waiting for Sale, Richmond, Virginia (1861) and the export of printed cotton from Manchester, it examines the convergence of the trade in cotton with the trade in slaves. It considers how these market relations shaped the commodification of the enslaved body, British experiences of factory labor, and Manchester production of printed cloth for consumers across the globe. Chapter three begins with Leonardo Drew's Number 25 to consider the tensions between materiality and abstraction in the production and commodification of cotton and art objects. I then examine paintings by Edgar Degas, A Cotton Office in New Orleans (1873), and Winslow Homer, The Cotton Pickers, (1876) to explore how these artists negotiated the status of cotton as a global commodity and grappled with the changing networks, of labor, production and commerce in postbellum America. Eyre Crowe's painting of factory workers in Lancashire, The Dinner Hour, Wigan (1874) concludes this section, which examines how the international market for cotton was influencing the representation and experience of industry in north west England. My final chapter, commencing with an installation by Yinka Shonibare MBE Scramble for Africa (2003), focuses on the commercial logic and visual rhetoric of three Southern international exhibitions. I examine how these exhibitions constructed the South – through visions of cotton plantations and black cotton pickers – as a space for domestic colonial expansion. Alongside this I look at the ways Africa was being constructed as a new cotton market – both as a site of cultivation and a site of consumption. In both sections I underscore how the language of commerce, colonialism and cotton shaped particular constructions of space and meanings around the African, and African American body. I conclude with the work of Meta Warrick Fuller to briefly examine how black Americans dismantled these tropes of exclusion, signified by cotton, to project claims for equality.

The project argues that the art works under examination here draw on an economic language to visualize particular ideas and constructions around labor, production and race in three ways. It traces the contours of a market-driven aesthetic in the ways cotton was used to illustrate or materialize connections to a circulating economy of goods. It describes how cotton's movement shaped the construction of imagined geographies around sites of labor and spaces of consumption. And it sketches out the speculative vision that emerged throughout the nineteenth century in the material and metaphorical associations of cotton, commerce and African American identity. In revealing the representational possibilities of cotton in this way, this dissertation looks at understudied objects to consider the nuanced ways that local cultural forms have, historically, intersected with global processes in the Atlantic world. It centralizes the experience of African Americans, within an Anglo-American culture of exchange and its relationship to a global network of trade and transmission. In doing so it seeks to reframe the ways we might approach historical processes of visuality and perception in the long nineteenth century in order to create a more global, or at least transnational, perspective on the art of this period.

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Siegelman, Lia. "Ageostrophic dynamics in the ocean interior A correction for the thermal mass–induced errors of CTD tags mounted on marine mammals, in the Journal of Atmospheric and Oceanic Technology 35 (6), June 2018 Submesoscale ocean fronts act as biological hotspot for southern elephant seal, in Scientific Reports 9, 2019 Ocean‐scale interactions from space, in Earth and Space Science 6(5), May 2019 Correction and accuracy of high- and low-resolution CTD data from animal-borne instruments, in the Journal of Atmospheric and Oceanic Technology 36 (5), May 2019 Diagnosing ocean‐wave‐turbulence interactions from space, in Geophysical Research Letters 46(15), August 2019 Sub‐mesoscale fronts modify elephant seals foraging behavior, in Limnology and Oceanography Letters, 4(6), December 2019." Thesis, Brest, 2019. http://www.theses.fr/2019BRES0094.

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L'océan est le plus grand réservoir d'énergie solaire de notre planète. La quantité de chaleur qu'il est capable de stocker est modulée par sa circulation complexe, opérant sur une vaste gamme d’échelles allant du centimètre à la dizaine de milliers de kilomètres. Cette thèse s'intéresse à deux types de processus océaniques: les tourbillons de mésoéchelle, d'une taille de 100 à 300 km, et les fronts de sous-mésoéchelle, d'une taille inférieure à 50 km. L'idée communément admise est que les mouvements agéostrophiques de sous-mésoéchelle sont principalement confinés à la couche de mélange océanique de surface et sont faibles dans l'océan intérieur. Cette vision classique de la dynamique océanique repose sur l'hypothèse que l'océan intérieur est en équilibre quasi-géostrophique, empêchant la formation de forts gradients de densité en profondeur. Cette thèse remet en question ce paradigme en se basant sur des observations CTD in situ à haute résolution collectées par des éléphants de mer instrumentés, des images satellite d’élévation de la surface de l’océan, et des sorties de modèle à haute résolution dans le Courant Circumpolaire Antarctique.Les résultats indiquent que les mouvements agéostrophiques sont (i) générés par le champ tourbillonnaire de mésoéchelle via des processus defrontogenèse, et (ii) ne sont pas limités à la couche de mélange de surface ; bien au contraire, ils pénètrent dans l'océan intérieur jusqu'à 1000 m deprofondeur. Ces fronts agéostrophiques de sous-mésoéchelle sont associés à d'importants flux de chaleur dirigés de l'intérieur de l'océan vers la surface, d'une amplitude comparable aux flux air-mer.Cet effet peut potentiellement altérer la capacité de stockage de chaleur de l'océan et devrait être le plus fort dans les zones tourbillonnaires telles que le Courant Circumpolaire Antarctique, le Kuroshio et le Gulf Stream, les trois courants clefs du système climatique. Il apparaît ainsi que les fronts agéostrophiques de sous-mésoéchelle représentent une voie importante, mais encore largement méconnue, pour le transport de chaleur, de nutriments et de gaz entre l'intérieur et la surface de l'océan, avec des répercussions potentiellement majeures pour les systèmes biogéochimique et climatique
The ocean is the largest solar energy collector on Earth. The amount of heat it can store is modulated by its complex circulation, which spans a broad range of spatial scales, from centimeters to thousands of kilometers. This dissertation investigates two types of physical processes: mesoscale eddies (100-300 km size) and submesoscale fronts (£ 50 km size). To date, ageostrophic submesoscale motions are thought to be mainly trapped within the ocean surface mixed layer, and to be weak in the ocean interior. This is because, in the classical paradigm, motions below the mixed layer are broadly assumed to be in quasigeostrophic balance, preventing the formation of strong buoyancy gradients at depth. This dissertation introduces a paradigm shift; based on a combination of high-resolution in situ CTD data collected by instrumented elephant seals, satellite observations of sea surface height, and high-resolution model outputs in the Antarctic Circumpolar Current, we show that ageostrophic motions (i) are generated by the backgound mesoscale eddy field via frontogenesis processes, and (ii) are not solely confined to the ocean surface mixed layer but, rather, can extend in the ocean interior down to depths of 1 000 m. Deepreaching ageostrophic fronts are shown to drive an anomalous upward heat transport from the ocean interior back to the surface that is larger than other contributions to vertical heat transport and of comparable magnitude to air-sea fluxes. This effect can potentially alter oceanic heat uptake and will be strongest in eddy-rich regions such as the Antarctic Circumpolar Current, the Kuroshio Extension, and the Gulf Stream, all of which are key players in the climate system. As such, ageostrophic fronts at submesoscale provide an important, yet unexplored, pathway for the transport of heat, chemical and biological tracers, between the ocean interior and the surface, with potential major implications for the biogeochemical and climate systems

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25

De, Figueiredo Mark A. (Mark Anthony) 1978. "The Hawaii carbon dioxide ocean sequestration field experiment : a case study in public perceptions and institutional effectiveness." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/16929.

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Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.
Includes bibliographical references.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
In December 1997, an international project agreement was signed in Kyoto for a collaborative study of the direct injection of carbon dioxide into the deep ocean. After a detailed international site selection process, the Natural Energy Laboratory of Hawaii Authority (NELHA), a quasi-governmental organization, was chosen as the host for the project in March 1998. In addition to fulfilling the necessary technical criteria, NELHA maintained an ocean research corridor, and it was impressed upon the project team that this could facilitate the permitting process. International steering and technical committees served as advisors to the Hawaii-based project general contractor, Pacific International Center for High Technology Research. The committees also planned a multi-year public outreach program to engage residents of Hawaii about the carbon sequestration project. Before the outreach program began, a reporter wrote about the planned carbon sequestration experiment in a March 18, 1999 front-page article in the local newspaper, West Hawaii Today. As a result, some members of the community started organizing an opposition to the project, culminating in the creation of the "Coalition Against CO2 Dumping." Concerns raised by the opposition included the environmental impacts on the ocean ecology, Not-In-My-Backyard feelings, anti-fossil fuel sentiment, and issues regarding native Hawaiian sovereignty. The project team reacted by implementing a dual public relations and outreach strategy, creating a website, responding to hundreds of emails and letters, and holding public meetings. A major fallout from the opposition was that permitting became much more difficult, involving multiple agencies on the state and federal level. In addition, the controversy affected the project's relationship to its NELHA host and caught the attention of the Hawaii state legislature. After the project team conducted an Environmental Assessment, US Department of Energy issued a Finding of No Significant Impact (FONSI), an important milestone in the permitting process. This thesis summarizes the events from project start through the issuing of the FONSI, discusses the lessons learned from the experience, and provides recommendations for institutions dealing with public perception issues in future projects.
by Mark Anthony de Figueiredo.
S.M.

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26

Taha, Ahmed Mohamed Youssef. "Investigating an interactive technological self study conceptual framework for on-board maritime education and training." Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/9149/.

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Merchant marine officers have multiple specific duties and responsibilities to perform. Moreover, there is a need for a well-trained workforce to operate modern ships. In this era, the development of technological tools to assist in the delivery of the syllabus, and develop the marine cadets’ practical knowledge during training on-board is highly required. This study reviewed literature concerning Maritime Education and Training, in addition to personalised learning and online mobile learning. The research proposes the creation, assessment and validation of generic Interactive Maritime Education and Training (iMET) application, that is utilising Near Field Communication (NFC) technology, as a personalised interactive self-study mobile tool, with respect to cadets’ different learning preferences. The main aim of this research is to test the hypothesis that, the iMET tool has a direct positive impact on the Maritime Education and Training process on-board the training ship, and it is an accepted technology, hence will be actually used by the cadets on-board. In order to evaluate the research hypothesis, the researcher developed a generic prototype of iMET handheld application, as a proof of concept. Moreover, the researcher adapted a Technology Acceptance Model (TAM), from the existing TAM models, that had been used in previous research, in order to asses cadets’ acceptance to the proposed iMET application. Data collection in this research was based on triangulation, in order to measure the perception and expectations of the different maritime stakeholders affiliated with the iMET tool implementation. Accordingly, a questionnaire survey, a semi-structured interview and a quiz for cadets’ assessment was conducted. Data collection and surveys were conducted twice, in the pre iMET intervention development phase and post iMET intervention validation phase, in order to support justifying and validating the proposed technological tool in the current study. This research philosophy is a pragmatic research approach that applied a mixed methodology, to measure the cadets’ technology acceptance of iMET and their behavioural intention towards its actual usage. Finally, the research will discuss in detail the outcomes and finding.

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Pradhan, Suman. "Measurement of bubble velocity vectors in bubbly air water multiphase flow." Thesis, University of Huddersfield, 2010. http://eprints.hud.ac.uk/id/eprint/9247/.

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Measurement of the volumetric flow rate of each of the flowing components in multiphase flow is often required and this is particularly true in Production Logging applications. Thus, an increasing level of interest has been shown in making flow rate measurements in multiphase flow. A new generation of tomographic instrument, which enables measurement of the instantaneous local velocity vector and the instantaneous local volume fraction of the dispersed phase, is now being introduced. However validation and calibration of such instruments is necessary. This thesis describes the development of a miniaturised local four-sensor conductivity probe capable of acquiring measurements of the local velocity vector, gas volume fraction and the local axial gas velocity in the bubbly gas-liquid flows. Experimental techniques in which the probe was used to obtain the local gas velocity vector and the local gas volume fraction in a bubbly gas-liquid flow are also described. High speed cameras are introduced for the measurement of the reference velocity of the bubbles. The camera images are also used to plot the trajectory of any bubble that hits all four-sensor of the probe. Extensive experimental results showing the distribution of the local gas volume fraction and the local axial, azimuthal and the radial bubble velocity components in vertical and swirling gas-liquid flows are presented.

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Wiratama, Nugroho. ""Blue heart ocean": a new technology of coral reef conservation in the implementation of fisheries sustainable economics, case studies jakarta waterfront city north Jakarta." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/10343.

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29

Hansson, Mikael. "Critical review of strategic theories : Applicable to new technologies." Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-77124.

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30

Meckassoua, Abdou Karim. "Etudes comparées des activités de régulation d'un dispositif automatisé dans le cadre d'un transfert de technologie." Paris, CNAM, 1986. http://www.theses.fr/1986CNAM0083.

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31

Harries, Tom. "Physical testing and numerical modelling of a novel vertical-axis tidal stream turbine." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/66145/.

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A combination of climate change, due to anthropogenic CO2 emissions and concerns over energy security, due to fluctuating fuel prices, has led to the UK pushing to increase its renewable energy production. Harnessing tidal stream energy is an infant sector in the UK’s renewable energy portfolio, despite the UK’s large tidal stream resource, and is harnessed through deploying tidal stream energy converters. This thesis focuses on the design of a novel vertical axis tidal turbine (VATT) called CarBine which is driven by drag force and therefore has several unique advantages, including slow rotational speed, omni-directionality and a simple design. This research focused on the optimisation of the CarBine design and was split into two areas: physical testing and numerical modelling. A conventional Savonius was also analysed in both of these respects and this enabled a direct comparison of CarBine to a competing drag force driven VATT. Physical testing measured the power of the turbines and was conducted in hydraulic flumes at both Cardiff University (CU) and IFREMER in Northern France for a range of flow conditions. Testing at IFREMER enabled the quantification of the blockage effect in the CU experiments. Physical testing resulted in the optimised design of CarBine being one with a four arm configuration. From physical testing at CU, CarBine showed inferior efficiency performance to that of the conventional Savonius, a Cp of 0.117 compared to 0.225 at U∞=0.72 m/s. As a result a hybrid of both the Savonius and CarBine was tested, namely a Savonius with flaps. However, results from physical testing showed the Savonius with flaps to have inferior performance to both CarBine and the conventional Savonius, with a Cp of 0.103 at U∞=0.72 m/s at CU. Numerical modelling was conducted using the commercial CFD software package, Ansys CFX. Both transient and steady state simulations along with 2D and 3D models were used to model both CarBine and the Savonius. Both the k-ε and SST turbulence models were used for comparison. The two degrees of rotational freedom present in the CarBine design resulted in CarBine being difficult to model precisely. The numerical modelling results were validated against the physical testing results and where available, 3D results showed closer validation than the 2D results.

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Hudson, Andrew Philip. "Evaluation of the vertical and horizontal hydraulic conductivities of household wastes." Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/79368/.

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Hydraulic conductivity is a measurement of the ease of movement of a fluid through a medium and is therefore a key parameter in the design of landfill leachate management systems. Hydraulic conductivity of landfilled wastes may be affected by several factors such as overburden stress from the weight of overlying waste, water content, the type, age and pre-processing of the waste, and the presence of landfill gas. A further factor that may affect leachate movement through wastes is the predominantly horizontal orientated structure of compacted wastes. This anisotropic structure may result in hydraulic conductivity in the horizontal direction being greater than that in the vertical direction. However existing research has been effectively limited to evaluating hydraulic conductivity in a single plane and so the presence of anisotropic flow in waste remains unproven. Consequently, modelling of leachate and contaminant movement in landfills may be compromised by the use of isotropic, or assumed anisotropic, hydraulic conductivity values. The object of this research has been to assess for the first time the inherent anisotropy of two different waste samples by measuring and comparing the vertical and horizontal hydraulic conductivities over a range of stresses typical of landfill conditions. In this thesis, factors affecting the measurement of hydraulic conductivity of wastes are discussed, and details of the samples tested and test methodology are given. The results of the tests are shown and alternative test methods are discussed. The effects of gas accumulation and pore water pressure on waste hydraulic conductivity encountered during testing are also reported as further research has developed from this important finding.

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Langesfeld, Ivan. "Fragile Oceans, Synthetic Flotsam and Microbial Collaboration – Explorations in the Visual Communication of the Plastic Crisis." Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/pomona_theses/210.

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Scientific evidence that the ocean plastic crisis is larger in scale and more sinister than previously thought continues to mount, but the rate of plastic production is only rising. What will it take to decisively turn the tide against plastic? We need scientists, politicians, and industry changemakers to continue producing knowledge and positive change in the industry, but we need to go further still. This thesis explores art as an alternative visual communication strategy with the capacity to encourage curiosity, empathy, and positive engagement with the issue of ocean plastics. The series of work explores bacterial bioluminescence as an artistic medium in juxtaposition with objects of found ocean plastic. The photographs in the series build on the concepts of mutualism, illumination, critical densities, and interspecies communication to reimagine how we might further the discourse around ocean plastic.

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34

Rydahl, Björn. "A VFX ocean toolkit with real time preview." Thesis, Linköping University, Department of Science and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-50850.

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35

Ng, Warren Heng Wan. "Identification, transport and treatment of adhered deleterious substances of stormwater in an urban catchment thesis submitted in fulfilment of the degree of Doctor of Philosophy, Earth & Oceanic Sciences Research Institute, Auckland University of Technology, August 2004 /." Full thesis. Abstract, 2004. http://puka2.aut.ac.nz/ait/theses/NgW.pdf.

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36

Al-Hinai, Sulaiyam. "Non-invasive velocity and volume fraction profile measurement in multiphase flows." Thesis, University of Huddersfield, 2010. http://eprints.hud.ac.uk/id/eprint/9094/.

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Multiphase flow is the simultaneous flow of two or more phases, in direct contact, and is important in the oil industry, e.g. in production wells, in sub-sea pipelines and during the drilling of wells. The behaviour of the flow will depend on the properties of the constituent phases, the flow velocities and volume fractions of the phases and the geometry of the system. In solids-in-liquid flows, measurement of the local solids volume fraction distribution and the local axial solids velocity distribution in the flow cross section is important for many reasons including health and safety and economic reasons, particularly in oil well drilling operations. However upward inclined solidsliquid flows which are frequently encountered during oil well drilling operations are not well understood. Inclined solids-liquid flows result in non- uniform profiles of the solids volume fraction and axial solids velocity in the flow cross- section. In order to measure the solids volumetric flow rate in these situations it is necessary to measure the distributions of the local solids volume fraction and the local axial solids velocity and then to integrate the product of these local properties in the flow cross section. This thesis describes the development of a non-intrusive Impedance Cross-Correlation (ICC) device to measure the local solids volume fraction distribution and the local solids axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes, denoted „array A‟ and „array B‟, separated by an axial distance of 50mm. At each array, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for arrays A and B, any of the eight electrodes can be configured as an "excitation electrode" (V+), a "virtual earth measurement electrode" (Ve) or an "earth electrode" (E) thus enabling the local mixture conductance in different regions of the flow cross-section to be measured and thereby allowing the local solids volume fraction in each region to be deduced. The conductance signals from arrays A and B are also cross-correlated to yield the local solids axial velocity in the regions of flow under interrogation. A number of experiments were carried out in solids-in-water flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at three different inclination angle to the vertical ( o 0 , o 15 and o 30 ). The obtained results show good quantitative agreement with previous work carried out using intrusive local probes. Integration of the flow profiles in the cross section also yielded excellent quantitative agreement with reference measurements of the mean solids volume fraction, the mean solids velocity and the solids volumetric flow rate. Furthermore, this study also showed good qualitative agreement with high speed film of the flow. It is believed that the method of velocity and volume fraction profile measurement described in this thesis is much simpler to implement, more accurate and less expensive than the currently very popular technique of dual-plane Electrical Resistance Tomography (ERT). Finally, the thesis describes a mathematical model for predicting the axial velocity distribution of inclined solids-water flows using the solids volume fraction profiles measured by the ICC device. Good agreement was obtained between the predicted velocity profiles and the velocity profiles measured using the ICC device.

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37

Lindroth, [formerly Tyrberg] Simon. "Buoy and Generator Interaction with Ocean Waves : Studies of a Wave Energy Conversion System." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160085.

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On March 13th, 2006, the Division of Electricity at Uppsala University deployed its first wave energy converter, L1, in the ocean southwest of Lysekil. L1 consisted of a buoy at the surface, connected through a line to a linear generator on the seabed. Since the deployment, continuous investigations of how L1 works in the waves have been conducted, and several additional wave energy converters have been deployed. This thesis is based on ten publications, which focus on different aspects of the interaction between wave, buoy, and generator. In order to evaluate different measurement systems, the motion of the buoy was measured optically and using accelerometers, and compared to measurements of the motion of the movable part of the generator - the translator. These measurements were found to correlate well. Simulations of buoy and translator motion were found to match the measured values. The variation of performance of L1 with changing water levels, wave heights, and spectral shapes was also investigated. Performance is here defined as the ratio of absorbed power to incoming power. It was found that the performance decreases for large wave heights. This is in accordance with the theoretical predictions, since the area for which the stator and the translator overlap decreases for large translator motions. Shifting water levels were predicted to have the same effect, but this could not be seen as clearly. The width of the wave energy spectrum has been proposed by some as a factor that also affects the performance of a wave energy converter, for a set wave height and period. Therefore the relation between performance and several different parameters for spectral width was investigated. It was found that some of the parameters were in fact correlated to performance, but that the correlation was not very strong. As a background on ocean measurements in wave energy, a thorough literature review was conducted. It turns out that the Lysekil project is one of quite few projects that have published descriptions of on-site wave energy measurements.

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38

Selig, Michael. "The influence of internal tyre pressure on road friction." Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/21030/.

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Road safety is a very important topic for research and development divisions in the automotive industry. As the tyre is the only link between road surface and vehicle, it plays a very significant role in accident mitigation and prevention. This thesis investigates the influence of internal tyre pressure on the brake distance both experimentally and theoretically. Brake tests were performed using a robotic system and a winch was used to pull a car with locked wheels. For both experiments, the tyre pressures were changed. A rubber friction law is presented which can be used for tyre and vehicle dynamics calculations. The friction law was tested by comparing numerical results to the full rubber friction theory of Persson and to experimental data. A two-dimensional (2D) tyre model is introduced that combines the rubber friction law with a simple mass-spring description of the tyre body. The tyre model is very flexible and can be applied to different manoeuvres. It can be used to calculate μ-slip curves, self aligning-torque, braking, and cornering, or combined motion (e.g. braking during cornering). The theoretical predictions have been compared to measured data from indoor tyre testing on sandpaper substrate. Additionally simulations of anti-lock braking system (ABS) using two different control algorithms are presented. In addition a method for rapidly changing the tyre inflation pressure while a vehicle is in motion is presented. This method can be used for novel safety system approaches.

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39

Usman, A. Y. "A resilience modelling approach for oil terminal operations under high uncertainties." Thesis, Liverpool John Moores University, 2017. http://researchonline.ljmu.ac.uk/6602/.

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Oil terminals are complex infrastructures due to their diverse operational activities. They are exposed to diverse risks because they usually operate in a dynamic environment in which safety barriers are sometime overwhelmed, leading to the disruption of operations due to a high level of uncertainty. However, the ability of oil terminals to minimise vulnerability and maximise resilience depends on the availability of the correct anticipated information at the right time for a decision-making process. An important finding from the reviewed literature revealed that uncertainties and the unpredictability of the convergent effect of several hazardous factors have the potential to cause major disruptions such as fire, explosion and transit accidents. The consequences of these disruptions can lead to infrastructure damage and loss of life. The common operational threats to oil terminal operations (OTOs) substantiates the need for a holistic resilience model for operations in offshore/onshore terminals such as berthing/unberthing, vessel manoeuvring, loading and offloading, storage, etc. Due to the uncertainties associated with these operations and the cases of reported incidents/accidents, this research focuses more on the aspect of loading and offloading operations at ship/terminal interface. An emphasis on a resilience modelling approach provides a flexible yet robust model for OTOs to address disruption proactively, particularly with constantly evolving hazards and threats. This thesis introduces an innovative approach towards resilience modelling based on a developed novel framework. The key aspect of the framework was supported using three proposed models: (1) the integration of Utility Theory and Swiss Cheese Model (UtiSch_+), to evaluate the relative importance of the identified hazard factors (HFs), (2) a Bayesian network (BN), to calculate the overall probability that a specific hazard is present and, (3) an Analytical Hierarchical Process (AHP) - Prospect Theory (PT) approach, as an important model for a strategic decision selection method. An empirical study was conducted to test the validity the proposed models, using case studies and Sensitivity Analysis (SA). The result obtained demonstrated that the models are effective techniques to obtain the relative weight of the identified Hazard Factors (HFs) in order to prioritise them, for dynamic hazards probability evaluation and to prioritise suggested resilience strategies in order of importance to mitigate hazard/risk level. Evidently, the result revealed appears reasonable and appropriate for investment, in order to support a strategic decision for the selection of a resilience strategy for resilience improvement in OTOs.

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40

Bolstad, K. S. "Systematics of the Onychoteuthidae Gray, 1847 (Cephalopoda: Oegopsida) a thesis submitted to the Earth & Oceanic Sciences Research Institute, Auckland University of Technology in fulfilment of the requirements for the degree of Doctor of Philosophy, supervised by Dr Steve O'Shea, 2008." Click here to access this resource online, 2008. http://hdl.handle.net/10292/414.

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41

Al-Yarubi, Qahtan. "Phase flow rate measurements of annular flows." Thesis, University of Huddersfield, 2010. http://eprints.hud.ac.uk/id/eprint/9104/.

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In the international oil and gas industry multiphase annular flow in pipelines and wells is extremely important, but not well understood. This thesis reports the development of an efficient and cheap method for measuring the phase flow rates in two phase annular and annular mist flow, in which the liquid phase is electrically conducting, using ultrasonic and conductance techniques. The method measures changes in the conductance of the liquid film formed during annular flow and uses these to calculate the volumetric and mass flow rates of the liquid film. The gas velocity in the core of the annular flow is measured using an ultrasonic technique. Combined with an entrainment model and the liquid film measurements described above, the ultrasonic technique enables the volumetric flow rate of the gas in the core and the volumetric and mass flow rates of entrained liquid droplets to be measured. This study was based on experimental work and the use of modelling techniques. The practical investigation comprised a series of experiments conducted on a purpose built flow loop in which the test section was a Perspex pipe of 50mm ID. The experimental work was limited to two-phase air-water flow. The flow loop was specifically designed to accommodate the different instruments and subsystems designed in this investigation including bespoke flow meters and a film extraction system. Most flow loop controls were automated using a MATLAB program. Reference measurement of the total water flow rate was made using a calibrated turbine flow meter and of the air flow rate using a calibrated rotameter. For the combined ultrasonic/conductance method investigated in this thesis, the velocity of the gas in the core was found using a novel Ultrasonic Flow Meter (USFM). The positioning and arrangement of the transducers have never been used previously. The flow velocity of the liquid film and the thickness of the film were measured using a novel Conductance Flow Meter (CFM). The CFM measured the liquid film thickness using novel wall conductance probes. By cross correlating the signals from a pair of such probes the film velocity was obtained. Good agreement of the experimental results obtained from the CFM and USFM with results published in the literature was found. Although not investigated experimentally in the work described in this thesis, annular flows encountered in the oil industry may contain a liquid phase comprising a mixture of oil and water. For such flows, the volume fractions of the oil and water can be measured using an automated bypass system developed during this project. The bypass system periodically extracts part of the liquid film, measures its density and then releases the sample back into the pipeline. The liquid phase volume fractions are determined from this density measurement which can be performed more than once per minute. An entrainment model was developed, which is required by the ultrasonic/conductance flow metering technique described in this thesis, in which the mass fraction of the liquid flowing as entrained droplets in the core can be determined from the liquid film thickness and velocity measurements. A mathematical model was also developed to describe the properties of the liquid film, such as liquid velocity profile within the film, and the model’s results were found to agree with the experimental results obtained during the project and also with previous work cited in the literature. The complexity of this latter model was reduced by making a number of simplifying assumptions, which are presented and discussed in the thesis, including the assumption that in annular flow there is a dynamic balance liquid entrainment and droplets being deposited back onto the film. The combination of the designed CFM and USFM with the bypass tube and the entrainment model offer the opportunity for a ‘wet gas’ flow meter to be developed to measure two and three phase annular flows at relatively low cost and with enhanced accuracy. Such a device would have the advantage that it would by substantially smaller than systems using separators and it could even be retrofitted onto off-shore platforms. The integration of the subsystems developed in this project into a single system capable of giving on-line measurements of annular flow would be a major benefit to the author’s sponsor, Petroleum Development of Oman.

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42

Kameswar, Rao Vaddina. "Evaluation of A Low-power Random Access Memory Generator." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7823.

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In this work, an existing RAM generator is analysed and evaluated. Some of the aspects that were considered in the evaluation are the optimization of the basic SRAM cell, how the RAM generator can be ported to newer technologys, automating the simulation process and the creation of the workflow for the energy model.

One of the main focus of this thesis work is to optimize the basic SRAM cell. The SRAM cell which is used in the RAM generator is not optimized for area nor power. A compact layout is suggested which saves a lot of area and power. The technology that is used to create the RAM generator is old and a suitable way to port it to newer technology has also been found.

To create an energy model one has to simulate a lot of memories with a lot of data. This cannot be done in the traditional way of simulating circuits using the GUI. Hence an automation procedure has been suggested which can be made to work to create energy models by simulating the memories comprehensively.

Finally, basic ground work has been initiated by creating a workflow for the creation of the energy model.

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43

Doyle, Paul Norman. "The effects of human activities on stream water quality case studies in New Zealand and Germany : thesis submitted in partial fulfilment of the degree of Master of Applied Science, Earth and Oceanic Sciences Research Institute, Auckland University of Technology, Auckland, New Zealand, September 2005." Full thesis. Abstract, 2005.

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44

Dewas, Severine E. A. "Benthic-invertebrate diversity of Tucetona laticostata (Mollusca: Bivalvia) biogenic substrata in Hauraki Gulf a thesis submitted through the Earth & Oceanic Sciences Research Institute, Auckland University of Technology, in partial fulfilment of the requirements for the degree of Master of Applied Science (MAppSc), 2008 /." Click here to access this resource online, 2008. http://hdl.handle.net/10292/454.

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45

Islas-Cital, Alan. "Amplitude and phase sonar calibration and the use of target phase for enhanced acoustic target characterisation." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3460/.

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This thesis investigates the incorporation of target phase into sonar signal processing, for enhanced information in the context of acoustical oceanography. A sonar system phase calibration method, which includes both the amplitude and phase response is proposed. The technique is an extension of the widespread standard-target sonar calibration method, based on the use of metallic spheres as standard targets. Frequency domain data processing is used, with target phase measured as a phase angle difference between two frequency components. This approach minimizes the impact of range uncertainties in the calibration process. Calibration accuracy is examined by comparison to theoretical full-wave modal solutions. The system complex response is obtained for an operating frequency of 50 to 150 kHz, and sources of ambiguity are examined. The calibrated broadband sonar system is then used to study the complex scattering of objects important for the modelling of marine organism echoes, such as elastic spheres, fluid-filled shells, cylinders and prolate spheroids. Underlying echo formation mechanisms and their interaction are explored. Phase-sensitive sonar systems could be important for the acquisition of increased levels of information, crucial for the development of automated species identification. Studies of sonar system phase calibration and complex scattering from fundamental shapes are necessary in order to incorporate this type of fully-coherent processing into scientific acoustic instruments.

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46

de, Ruyter Marcus J. M. "Two-dimensional cut plan optimization for cutter suction dredgers." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/79367/.

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Optimal cut plans for cutter suction dredgers aim to maximize operational efficiency. Maximizing operational efficiency involves minimization of stoppage time resulting from non-productive dredger movements. To automate a systematic search for optimal twodimensional cut plans for cutter suction dredgers two models with an adaptive simulated annealing-based solution approach were developed. The first model, the dredge cut nesting model, optimizes irregular stock cutting problems where stencils represent dredge cuts and sheets represent dredging areas. Stencils are collections of unit dredge cuts with dimensions related to an effective cutting width which can be achieved with the cutter suction dredger considered. The objectives of the dredge cut nesting model are to maximize sheet coverage and to minimize stencil overlap. Centroids of unit dredge cuts of final nest layouts are extracted and used as grid nodes in the second model. The second model, the dredger routing model, optimizes asymmetric travelling salesperson problems with turning costs. The objectives of the dredger routing model are to minimize total route length and sum of turning angles, and to maximize average link length. A link consists of two or more route edges which are aligned with each other to within specified limits. A significant result of this research is that an engineering application of both models showed that two-dimensional cut plans for cutter suction dredgers can be systematically optimized and that dredger routes with minimum turning costs can be found. However, results also showed that the dredger routing model is not yet sophisticated enough to find cut plans for cutter suction dredgers for which overall project execution time is minimal.

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Bassili, Niclas, and Douglas Eriksson. "An evaluation of deterministic prediction of ocean waves using pressure data to assist a Wave Energy Converter." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279600.

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Currently, existing devices for extracting electrical power from ocean waves all suffer from problems with low efficiency due to a lack of information about the incoming waves in advance. The complex dynamic nonlinear characteristics of the ocean make the prediction of these incoming waves a great challenge. This paper aims to investigate a deterministic short-term wave-by-wave prediction system, that can accurately predict the wave height and timing of the incoming waves, based on measurements from a submerged pressure sensor. The complete prediction process contains three steps, namely reconstruction, assimilation, and prediction. A nonlinear Weakly Dispersive Reconstruction method (WDM) is firstly employed to accurately calculate the surface elevation from the measured pressures. Afterwards, a variational assimilation method is used to convert the time series surface elevation to a spatial wavefield, to obtain initial conditions for the prediction. Lastly, a High Order Spectral Method (HOSM) deterministically predicts the evolution of the 2D irregular wavefield based on the acquired initial conditions. To verify the performance of this proposed prediction system, tests were conducted with data from irregular sea states with varying wave parameters, generated by simulations as well as model experiments in the controlled environment of a wave tank. The results show that the surface elevation can be predicted within 5% from the reference, for a future period of about 10 seconds for wavefields commonly experienced by a wave energy converter. Based on the results, a prediction is possible, but the accuracy heavily depends on the current sea state and the chosen prediction distance.The results have been compared against similar tests made using radar data and proven to be a viable alternative for certain sea states. In conclusion, pressure measurements, as a mean to sample an ocean wavefield, is shown to be a good option when combined with nonlinear reconstruction and prediction methods to assist the power harvesting capabilities of a wave energy converter.
Nuvarande enheter för att extrahera elektrisk energi från havsvågor lider av stora problem med låg effektivitet på grund av brist på information om de inkommande vågorna. Det komplexa ickelinjära dynamiska beteendet hos havsvågor gör förutsägelsen av dem till en stor utmaning. Det här arbetet syftar till att undersöka ett deterministiskt kortsiktigt system för att förutspå våg för våg, som noggrant kan förutspå våghöjd och tidpunkt för de inkommande vågorna, baserat på mätdata från en dränkbar trycksensor. Den kompletta förutsägelseprocessen innehåller tre steg, rekonstruktion, assimilering och förutsägelse. En ickelinjär weakly dispersive reconstruction method används först för att med hög noggrannhet beräkna ythöjningen från det uppmätta trycket. Därefter, används en variational assimilation method för att konvertera en tidsserie av ythöjningen till ett rumsligt vågfält, för att erhålla initialvillkor för förutsägelsen. Slutligen används en High Order Spectral Method för att deterministiskt förutspå utvecklingen av det tvådimensionella oregelbundna vågfältet baserat på de förvärvade initialvillkoren. För att verifiera prestandan av det föreslagna förutsägelsesystemet, så genomfördes tester med data från olika oregelbundna havstillstånd med varierande parametrar, genererade av simuleringar, såväl som modellexperiment utförda i en kontrollerad miljö i form av en vågtank. Resultaten från testerna visar att ythöjningen förutspås inom 5% från referensen, för en period på 10 sekunder framåt i tiden, för vågor som ett vågkraftverk vanligtvis utsätts för. Baserat på resultatet, så är det möjligt att förutspå inkommande vågor, men noggrannheten beror kraftigt på det aktuella havstillståndet och det valda avståndet för förutsägelsen. Resultaten har jämförts mot liknande tester gjorda med radardata och visat sig vara ett genomförbart alternativ för vissa havstillstånd. Sammanfattningsvis visas det att tryckmätningar, som ett medel för att mäta ett havsvågfält, är ett bra alternativ när de kombineras med ickelinjära rekonstruktions- och förutsägelsemetoder för att hjälpa till att öka ett vågkraftverks energigenerering.

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Gallego, Bonet Guillermo. "Variational image processing algorithms for the stereoscopic space-time reconstruction of water waves." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39480.

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A novel video observational method for the space-time stereoscopic reconstruction of dynamic surfaces representable as graphs, such as ocean waves, is developed. Variational optimization algorithms combining image processing, computer vision and partial differential equations are designed to address the problem of the recovery of the shape of an object's surface from sequences of synchronized multi-view images. Several theoretical and numerical paths are discussed to solve the problem. The variational stereo method developed in this thesis has several advantages over existing 3-D reconstruction algorithms. Our method follows a top-down approach or object-centered philosophy in which an explicit model of the target object in the scene is devised and then related to image measurements. The key advantages of our method are the coherence (smoothness) of the reconstructed surface caused by a coherent object-centered design, the robustness to noise due to a generative model of the observed images, the ability to handle surfaces with smooth textures where other methods typically fail to provide a solution, and the higher resolution achieved due to a suitable graph representation of the object's surface. The method provides competitive results with respect to existing variational reconstruction algorithms. However, our method is based upon a simplified but complete physical model of the scene that allows the reconstruction process to include physical properties of the object's surface that are otherwise difficult to take into account with existing reconstruction algorithms. Some initial steps are taken toward incorporating the physics of ocean waves in the stereo reconstruction process. The developed method is applied to empirical data of ocean waves collected at an off-shore oceanographic platform located off the coast of Crimea, Ukraine. An empirically-based physical model founded upon current ocean engineering standards is used to validate the results. Our findings suggest that this remote sensing observational method has a broad impact on off-shore engineering to enrich the understanding of sea states, enabling improved design of off-shore structures. The exploration of ways to incorporate dynamical properties, such as the wave equation, in the reconstruction process is discussed for future research.

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Strong, Rebecca. "The War on Plastics and Other Environmental Damages: An Analysis of Innovative Environmental Policies." Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/cmc_theses/2152.

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This thesis examines the environmental damages done by humans, such as plastic pollution, harmful energy production, and habitat destruction, and the things we are doing to correct them. It analyzes the costs and benefits government policies such as the ban of plastic products, along with creative innovations such as a sea vacuum and a cannon that shoots fish. Are we doing enough to heal the damage we have caused? Furthermore, can we change our behaviors to prevent more damage in the future?

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Bedford, Adam. "Strength in flexibility : research into innovative flexible bearing designs for wave convertor permanent magnet generators." Thesis, Lancaster University, 2011. http://clok.uclan.ac.uk/4192/.

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Originally this research was to investigate the use of hydrostatic bearings in large linear machines, such as linear generators, and determine their viability in a power generation context. It quickly became clear that it was possible to make hydro-static bearings viable, however the methods employed to do so gave rise to new possibilities which altered the scope of the research. The overall aim of the research has become to look at flexible construction, using modular generation units, as a means of creating more reliable and cost effective generators. The methods employed to do this involved modularising the generator's structure. Each module then acts as a generator in its own right transferring its power to the parent machine. The potential for each module design was assessed based on its losses, due to the bearings, and its economic potential, such as how it impacted the operation and maintenance costs or transport costs and consideration of how each design affected the power density of the parent machine. The basic structural analysis showed that, of the arrangements tried, there was a distinct advantage to restricting the number of bearings because it reduces energy losses. This is particularly true of designs that take advantage of the MMA concepts. The magnitude of the forces within the generators, during operation, lead to the creation 2-stage bearing and MMA concepts. The key reasons for them being to reducing dynamic forces within the generator and increase tolerance to design flaws and damage. Reducing the dynamic forces reduces losses in all types of bearings improving overall efficiency. Not all the concepts present in this document show commercial promise, however from the basic principles used to understand their working, there are some whose potential is clear. In general the modules have reduced the weight necessary to operate a successful generator and reduced the bearing losses no matter the type of bearing being used. Predicted force reductions mean that less strength critical and more cost effective materials can be used in the machines construction. Given that the original scope of the research was to assess a single type of bearing it has come a long way to incorporate construction methods that will reduce operation and transport costs, as well as being more efficient on some of the construction materials. The final module designs show great promise to increase the power density of generators whilst making them easy to maintain. Although hydrostatic bearings provide excellent lubrication the basic analysis performed herein shows that their energy consumption exceeds the energy loss of normal roller bearings reducing overall generator efficiency. The modular constructions presented may not provide a great jump in efficiency over previous designs however they do show a way to simplify operation and maintenance costs improving overall commercial viability. All 3D/CAD models contained herein were created by the author for this work unless otherwise stated/referenced.

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