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1

Troncoso, Abelleira Maria Teresa. „Batteries for marine applications“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-22408.

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The significant reduction in environmental emissions stated by the new IMO legislation, which specifies an amount of sulphur in fuels below 5% for 2020 and a NOx limit with an 80% reduction respect to the actual IMO limit within SECAS´s for 2016, aim the use of batteries as a propulsion source in hybrid marine power plants.Offshore vessels fit perfectly in the application of hybrid propulsion systems due to the large variations of energy requirements during their operation. Besides the reduction of emissions, the optimal combination between engines and batteries can be used for fast transients, smoothing the load of the engine and hence reducing the fuel consumption.The reasons behind the selection of the Lithium Ion battery as an ideal candidate for marine applications are stated in this thesis, through the comparison between the characteristics of different battery types.Simulation models of a Lithium Ion cell and a Lithium Ion battery pack at three complexity levels are developed in this thesis (simple, isothermal and thermal). Bond Graph approach is used for the model generation and 20Sim is used to perform the simulations.A safe operation window is stated for all levels since the performance of Lithium Ion cells is dependent on both, the temperature and the operating voltage. Therefore, both values must be kept within determined limits in order to avoid permanent damage in the cell.In case of the isothermal and thermal approaches, the electrochemical behaviour in the cell is considered and the main phenomena involved is represented, including: activation, conduction and diffusion, as well as, the dynamic effect of the electrochemical reactions and the heat release due to Joule heating.
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2

Margarit, Martín Gerard. „Marine applications of SAR polarimetry“. Doctoral thesis, Universitat Politècnica de Catalunya, 2007. http://hdl.handle.net/10803/6944.

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Els oceans mantenen una fràgil i complexa cadena que enllaça un alt nombre de factors biològics, sociològics i econòmics. Actualment, aquest ecosistema està amenaçat per l'activitat humana i uns dels punts més crítics és la sobreexplotació pesquera. Això ha despertat la consciencia de les autoritats d'arreu per a protegir l'entorn marí i assegurar, així, la seguretat i supervivència dels éssers humans. Tal objectiu demana el desenvolupament de polítiques de control que monitorin l'activitat dels vaixells.

Fins l'actualitat, diferents propostes s'han estudiat per monitorar vaixells, com per exemple transpondedors, teledetecció òptica i sensors acústics passius. L'experiència en entorns reals ha demostrat que cap d'aquestes solucions és eficient. Una alternativa poden ser els Radars d'Obertura Sintètica (SAR). Aquests sistemes utilitzen les propietats de reflectivitat i dispersió dels vaixells per identificar-los amb independència de qualsevol fenomen atmosfèric i del cicle dia/nit. El sensors SAR sintetitzen una obertura més gran que la real permetent l'obtenció d'imatges de reflectivitat d'uns quants kilòmetres d'amplada amb una resolució de pocs metres.

En la monitorització de vaixells, la tecnologia SAR ha demostrat unes bones prestacions per la detecció. Treu profit del fet que els vaixells dispersen més energia que el mar i, així, apareixen en les imatges com punts molt brillants. Però, la seva utilitat en la identificació de vaixells encara no està clara. Hi ha dues limitacions importants: 1) les resolucions dels sistemes actuals no semblen suficients per aïllar característiques geomètriques a partir de la informació de reflectivitat i 2) les distorsions que les signatures dels vaixells experimenten en entorns marins. Aquests problemes es poden resoldre parcialment si s'utilitzen dades SAR multidimensional. Aquest concepte es refereix al fet d'adquirir imatges SAR modificant un o més paràmetres del sistema. En la classificació de vaixells, hi ha dues opcions clares: 1) Polarimetria SAR (PolSAR) que utilitza les dues components polarimètriques de l'ona EM i 2) la Interferometria SAR que s'obté per la combinació de dues imatges SAR adquirides des de posicions molt properes. Per a una banda, la polarització de l'ona EM és una propietat intrínseca de l'ona que ajuda a aïllar estructures geomètriques particulars per mitjà de la teoria de descomposició de blancs (TD). Per l'altra, la interferometria treu profit de la diferencia de fase entre les dues imatges SAR per obtenir la tercera dimensió de l'escena.

PolSAR and InSAR presenten grans possibilitats per la monitorització de vaixells ja que poden solucionar algunes de les limitacions dels mètodes clàssics. Desafortunadament, encara no han estat profundament estudiades a causa de les dificultats en obtenir dades reals validades. Això ha limitat el nombre d'estudis en aquesta temàtica. En aquest entorn, la tesi està orientada a avaluar fins a quin punt les tècniques PolSAR i InSAR poden ser útils per la monitorització de vaixells. Per a tal propòsit, s'han fixat quatre objectius importants:
1. El desenvolupament d'un simulador SAR eficient que doni imatges realistes de vaixells i que solucioni el dèficit de dades reals en entorns marins.
2. L'estudi de la dispersió dels vaixells que fixi els principals mecanismes de dispersió observats en imatges SAR i com es relacionen amb la geometria dels vaixells.
3. Un estudi de les prestacions de les tècniques actuals d'anàlisis de dades PolSAR en la classificació de vaixells.
4. El desenvolupament d'un mètode nou i eficient per la identificació de vaixells.

Al llarg de la tesis, els diferents punts seran estudiats i resolts. El desenvolupament de GRECOSAR, un simulador SAR de blancs complexes que dóna imatges de vaixells similars a les adquirides en entorns reals, ha estat essencial per estudiar les propietats de dispersió dels vaixells. Ha permès demostrar que els vaixells es poden distingir a partir del seu patró dispersiu, el qual és senzill i dominat per alguns dispersors guia que presenten una marcada estabilitat i potència de dispersió. Amb aquests resultats ha estat possible desenvolupar un nou mètode que pot identificar vaixells sota condicions d'observació adverses. Combina característiques polarimètriques i interferomètriques SAR (PolInSAR) per inferir estimacions 3D de la geometria dels vaixells. Diferents tests han demostrat que aquest mètode dóna una millor fiabilitat en la identificació que altres mètodes actualment disponibles. Malgrat tot, fixa uns requeriments tecnològics més elevats, sobretot en la resolució de les imatges i en les característiques PolInSAR. La nova generació de sensors SAR els poden cobrir.
Oceans support a complex and fragile chain that links a high number of biological, sociological and economical factors. In these days, this ecosystem is endangered by human activity and one of the main hot spots is overfishing. As a result, authorities worldwide have become aware about the necessity to law-protect the marine environment in order to assure the safety and sustenance of human beings. This demands the development of fisheries policy to monitor the activities of ships.

Up to now, different vessel monitoring proposals have been considered, for instance transponders, optical remote sensing or passive acoustic sensors. The lessons learnt in real scenarios have shown that none of these solutions is efficient. A feasible option may be the so-called active Synthetic Aperture Radar (SAR) technology. It uses the reflectivity/scattering properties of vessels for basing the identification process with independence of any atmospheric phenomena and day/night cycle. SAR sensors synthesize an antenna aperture larger than the real one and this allows to acquire reflectivity images of some tens of kilometers wide with a resolution of few meters.

In vessel monitoring, SAR imagery has proven good performance for vessel detection. They take profit of the fact that vessels normally backscatter more power than the sea and, hence, they appear in the images as bright spots. But their usefulness in vessel identification has not been established yet. There are two main limitations, namely: 1) the resolution of current systems that appears to be not enough for isolating geometrical features from the reflectivity information of SAR images and 2) the distortions that vessel' signatures experiment within sea scenarios. Such problems can be solved up to certain extend if multidimensional SAR data is used. This concept refers to the possibility to acquire different SAR images by modifying one or more imaging parameters. In the scope of vessel classification, there are two main options, namely: 1) SAR polarimetry (PolSAR) that refers to the usage of the two polarimetric components of the EM wave and 2) SAR interferometry (InSAR) derived by combining two SAR images acquired from slightly different positions. On the one hand, the polarization of an EM wave is an intrinsic wave property that helps on identifying specific geometrical structures via Target Decomposition (TD) theory. On the other hand, Interferometry takes profit of the phase difference between the two SAR images to retrieve the third dimension of the scene.

PolSAR and InSAR have great potentialities for supporting vessel monitoring as they can overcome some of the limitations of classical methods. Unfortunately, they have not been exploited yet due to the difficulties on having at one's disposal real data with reliable ground-truth. This has limited the number of works tackling such issue. In this framework, the current thesis is focused to evaluate up to which extend PolSAR and InSAR imagery are reliable for vessel monitoring. For such purpose, four main goals are proposed, namely:
1. The development of an efficient SAR simulation environment that provides realistic vessel SAR images and overcomes the current data deficiency related to marine scenarios.
2. The study of vessel scattering to fix the main polarimetric scattering mechanisms observed in vessel SAR images and how they are related with the geometries of vessels.
3. A performance study of current analysis tools of PolSAR data in vessel classification.
4. The development of a novel and efficient methodology for vessel identification.

Along the thesis, the different points are studied and solved. The development of GRECOSAR, a SAR simulator of complex targets able to provide vessel images similar to those obtained in real scenarios, has been essential for studying the scattering properties of vessels. It has allowed to show that vessels can be distinguished by means of their scattering pattern, which appear to be not so complex and dominated by some guide scatters that present a marked reflectivity stability and scattered power. With these results, a new approach able to identify vessels even under adverse observation conditions has been developed. It combines polarimetric and interferometric SAR (PolInSAR) capabilities to retrieve 3D estimates of the geometry of ships. Different tests have shown that the proposed method provides better identification confidence than other available methods. However, it demands higher technological requirements in terms of image resolution and PolInSAR features. The new generation of SAR sensors may fulfill them.
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3

Knox, Esther M. „Marine applications for structural adhesives“. Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241876.

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4

Jayakumar, Gladstone Christopher. „Leathers for marine applications - 233“. Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34261.

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Content: Leather and leather products are known for its durability and luxuries which makes it more unique among the other synthetic materials. Breathability and visco-elastic properties make leather unique choice of biomaterial. Utilization of leathers in marine based applications is limited owing to reactivity of leather towards salt and weather conditions. Moreover, the choice of raw materials and chemicals used during leather manufacture has greatly influence the properties of the leather. An attempt has been made to understand the influence of sea conditions on leathers. Conventional chrome tanned and vegetable tanned leathers were incubated in sea water and subsequently processed into post tanning to evaluate the physical properties. To understand, the leaching of chemicals, dyed leathers are incubated at different humidity and saline conditions. Interestingly, chrome tanned leathers found to be friendlier to marine conditions whereas, vegetable tanned leathers lead to leaching of chemicals. Furthermore, leaching of chromium is negligible, and crust leathers resulted in soft leathers. Prolonged exposure of chrome tanned leathers under salt stress leads to more softness. This might be due to saline stress to the skin matrix. Moreover, the computability of conventional leather chemicals were also tested using sea water. The research provides a new insight on fine tuning the chemicals to suit marine based applications. Take-Away: A new insight on fine tuning the chemicals to suit marine based applications.
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Maistralis, Eleftherios. „Formal safety assessment of marine applications“. Thesis, Liverpool John Moores University, 2007. http://researchonline.ljmu.ac.uk/5843/.

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This research has first established that it is based on multiple methodologies developed to tackle the areas of engineering cargo handling systems, both at port and on-board vessels, as well as in the area of organisational self-assessment. It continued in reviewing the current status and future aspects of marine safety assessment together with an examination of a few major accidents. The major problems identified in marine safety assessment in this research are associated with inappropriate treatment of uncertainty in data and human error issues during the risk modelling estimation process and the calculation of failure probabilities. Following the identification of the research needs, this thesis has developed several analytical models for the safety assessment of cargo handling systems and organisational assessment structure. Such models can be effectively integrated into a risk-based framework using the marine formal safety assessment, safety case concepts. Bayesian network (BN) and evidential reasoning (ER) approaches applicable to cargo handling engineering systems have been proposed for systematically and effectively addressing uncertainty due to randomness and vagueness in data respectively. ER test cases for both a vessel selection process and a comparison of the safety maturity of different organisations in terms of self-assessment have been produced within a domain in which main and sub criteria have been developed for assessment reasons a long with the combination of the proposed model with existing organisational models. BN test case for a Liquefied Petroleum Gas (LPG) reliquefaction plant has been produced within a cause-effect domain in which Bayes' theorem is the focal mechanism of inference processing. A methodology aiming in finding the probability of failure when having variables ruled by uncertainty is established using certain variable transformation methods through the First and Second order reliability methodologies. Form/Sorm produces a most likely failure point, which is demonstrated through the application at a port cargo handling crane system. The outcomes have the potential to facilitate the decision-making process in a risk-based framework. Finally, the results of the research are summarised and areas where further research is required to improve the developed methodologies are outlined.
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Fagerberg, Linus. „Wrinkling of sandwich panels for marine applications“. Doctoral thesis, KTH, Aeronautical and Vehicle Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3587.

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The recent development in the marine industry with largerships built in sandwich construction and also the use of moreadvanced materials has enforced improvements of design criteriaregarding wrinkling. The commonly used Hoff’s formula isnot suited for the highly anisotropic fibre reinforced sandwichface sheets of today.

The work presented herein investigates the wrinklingphenomenon. A solution to wrinkling of anisotropic sandwichplates subjected to multi-axial loading is presented. Thesolution includes the possibility of skew wrinkling where thewrinkling waves are not perpendicular to the principal loaddirection. The wrinkling angle is obtained from the solutiontogether with the maximum wrinkling load. This method has beensupported with tests of anisotropic plates subjected touni-axial and bi-axial loading.

The effect of the face sheet local bending stiffness showsthe importance of including the face sheet stacking sequence inthe wrinkling analysis. The work points out the influence ofthe face sheet local bending stiffness on wrinkling. Threedifferent means of improving the wrinkling load except changingcore material is evaluated. The effect of the differentapproaches is evaluated theoretically and also throughcomparative testing. The transition between wrinkling and pureface sheet compression failure is investigated. Theoreticaldiscussions are compared with compressive test results of twodifferent face sheet types on seven different core densities.The failure modes are investigated using fractography. Theresults clearly show how the actual sandwich compressionfailure mode is influenced by the choice of core material,changing from wrinkling failure to face sheet micro bucklingfailure as the modulus density increases.

Finally, a new approach is presented where the wrinklingproblem is transferred from a pure stability problem to amaterial strength criterion. The developed theory providesmeans on how to decide which sandwich constituent will failfirst and at which load it will fail. The method give insightto and develop the overall understanding of the wrinklingphenomenon. A very good correlation is found when the developedtheory is compared with both finite element calculations and toexperimental tests.

Keywords:wrinkling, local buckling, imperfection,stability, anisotropy, sandwich

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7

Meskill, Shay J. „Applications of marine radar wave observation systems“. Thesis, Oregon Oregon State University, 2009. http://hdl.handle.net/10945/4299.

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This project utilized both shore-based and shipboard commercial marine radar technology to collect wave statistics. In the first application a shore-based system was installed at Yaquina Bay in Newport, Oregon in order to collect real-time wave information. This information was collected under the auspices of the Northwest Association of Networked Ocean Observing Systems (NANOOS) and will be used in ongoing studies on wave-current interaction. In the second application, a shipboard radar system was utilized to develop processing procedures and algorithms for collecting offshore wave data. These shipboard collections were in support of the environmental baseline study of the Reedsport Wave Energy Site, funded by the Oregon Wave Energy Trust (OWET).
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8

Byrne, John Charles. „Polynomial systems control design with marine applications“. Thesis, University of Strathclyde, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280403.

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9

Wilkie, J. „Static and dynamic optimisation with marine applications“. Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382414.

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10

Diyaroglu, Cagan. „Peridynamics and its applications in marine structures“. Thesis, University of Strathclyde, 2016. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26573.

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Prediction of fracture and failure is a challenging research area. There are various methods available in the literature for this purpose including well-known finite element (FE) method. FE method is a powerful technique for deformation and stress analysis of structures. However, it has various disadvantageous in predicting failure due to its mathematical structure since it is based on classical continuum mechanics (CCM). CCM has governing equations in the form of partial differential equations. These equations are not valid if the displacement field is discontinuous as a result of crack occurance. In order to overcome this problem, a new continuum mechanics formulation was introduced and named as Peridynamics. Peridynamics uses integrals equations as opposed to partial differential equations of CCM. Moreover, it does not contain any spatial derivatives. Hence, its equations are always valid regardless of discontinuities. In this thesis, the applications of Peridynamics for marine structues are demonstrated. Particularly, the Peridynamic equations are rederived for simplified structures commonly used in marine structures including beams and plates. Furthermore, underwater shock response of marine composites is investigated. Finally, the peridynamic formulation for contact analysis which can be used for collision and grounding of ship structures is demonstrated. In order to reduce the computational time, several solution strategies are explained.
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Bovio, Elena. „Champignons marins d'éponges marines : biodiversité, chimiodiversité et applications biotechnologiques“. Thesis, Université Côte d'Azur (ComUE), 2019. http://theses.univ-cotedazur.fr/2019AZUR4009.

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L'environnement marin est doté d’une diversité fongique encore trop faiblement explorée puisqu’on estime qu’environ 10% des champignons marins ont fait l’objet d’une étude. Dans ce contexte, le projet de thèse décrit dans ce manuscrit est focalisé sur le potentiel biotechnologique des champignons marins isolés d’éponges marines. Ces champignons sont caractérisés par une importante biodiversité et chimiodiversité susceptible de conduire à de nouvelles molécules bioactives. Il s’agit d’un projet pluridisciplinaire qui joint la mycologie, la chimie, la biochimie et les biotechnologies. Il couvre la stratégie complète de découverte de nouveaux produits naturels avec l'isolement et l'identification des souches fongiques à l’extraction et l'isolement des molécules ainsi que l’évaluation des propriétés biologiques. Le manuscrit est divisé en trois parties principales : - La première partie est dédiée à l’isolement des communautés fongiques cultivables associées à quatre éponges de l’océan Atlantique et trois éponges de Méditerranée. Nous avons obtenu au total 129 taxons parmi lesquels 84,5% ont pu être identifiées jusqu’au niveau de l’espèce via une approche polyphasique basée sur des techniques morphologiques, moléculaires et phylogénétiques. Parmi ces derniers, nous avons décrit pour la première fois deux espèces : Thelebolus balaustiformis et Thelebolus spongiae. Nos travaux ont permis de souligner la spécificité des communautés fongiques hébergées par chaque éponge ce qui laisse à penser que les éponges sont capables de recruter leur propre mycobiote. - La seconde partie est consacrée à l'étude de la diversité chimique des champignons marins associés à l'éponge Grantia compressa en utilisant l'approche OSMAC (une souche – de nombreux composés). Les résultats obtenus ont révélé les difficultés à obtenir des conditions de culture optimales. De façon générale et pour tous les champignons, les milieux riches en nutriments favorisent à la fois le développement du mycélium et la production de métabolites secondaires. Parmi les champignons isolés, Eurotium chevalieri MUT 2316 produits de nombreux métabolites, comparativement aux autres champignons. Dans ce contexte, nous avons pu isoler et caractériser dix composés. - La troisième partie est dédiée à l’évaluation des propriétés biologiques (pharmacologiques et environnementales) des différentes molécules isolées. Six composés ont montré des propriétés antibactériennes notamment l'isodihydroauroglaucine qui s’est avérée active vis-à-vis de la plupart des bactéries à Gram-positif testées et pour laquelle une activité bactéricide a pu également être décelée. La dihydroauroglaucine et le physcion inhibent complètement la réplication du virus de la grippe A tandis que la neoechinuline inhibe le virus de l'herpès simplex 1. Enfin, les différentes molécules ont été évaluées pour leurs propriétés antifoulings susceptibles de rentrer dans la composition de peintures plus respectueuses de l’environnement. Les molécules inhibent à de très faibles concentrations l'adhésion et la croissance de bactéries et de microalgues impliquées dans le biofouling. Par ailleurs, la combinaison de molécules isolées d’E. chevalieri MUT 2316 inhibe la totalité des bactéries et microalgues testées. Les travaux menés ont permis de mettre en avant l’importante biodiversité et chimiodiversité de champignons marins hébergés par les éponges. Les molécules isolées d’E. chevalieri MUT 2316 sont susceptibles de valorisation dans différents domaines de recherche tels que le développement de nouveaux médicaments ou de peintures antifoulings plus respectueuses de l’environnement
Marine environment represents an untapped source of fungal diversity, where it has been estimated that about 10% of fungi have been explored until now. Due to the lack of knowledge on marine fungi and their incredible biotechnological potential, this Ph.D. thesis focuses on a highly promising group of fungi: those associated with marine sponges. These fungi are both characterized by high biodiversity and chemodiversity, being the most successful producers of new bioactive molecules. On these premises, the main goal of the research was to cover the firsts and fundamentals aspects of the natural products discovery pipeline: from the isolation and identification of fungi from sponges to the isolation of molecules and the evaluation of their biological activity. This resulted in a multidisciplinary Ph.D. project that enclosed mycology, chemistry, biochemistry and biotechnology. In a “funnel-like” perspective, using multidisciplinary experimental approaches three main parts were developed: - The first aim was to isolate the fungal communities associated with sponges using several isolation techniques to increase the number of cultivable fungi. Four and three sponges were respectively collected in the Atlantic Ocean and in the Mediterranean Sea. Overall, 129 taxa were obtained; thanks to a polyphasic approach based on morphological, molecular and phylogenetic techniques, 84.5% of them were identified at the species level. Two fungal species Thelebolus balaustiformis and Thelebolus spongiae were here first described, updating the knowledge on marine fungal diversity. This work underlined the specificity of the fungal community for each sponge, leading to think that these animals are able to recruit their own mycobiota. - The second part was based on the investigation of the chemical diversity of marine fungi associated with the sponge Grantia compressa, using the OSMAC approach (One Strain – Many Compounds). Not surprisingly, it has been difficult to define a condition that promotes both the development of the mycelium and the secondary metabolites production for all fungi; generally, rich nutrients media are the best candidates to achieve the above-mentioned results. Among the tested fungi, Eurotium chevalieri MUT 2316 produce more metabolites than any other fungus and ten pure compounds were isolated. - The third part of this Ph.D. project aimed to test the biological activity of the ten fungal molecules. Two main research fields, pharmaceutical and environmental, were chosen as potential targets. Six compounds showed antibacterial activity, with isodihydroauroglaucin active against most of the Grampositive bacteria tested also with bactericidal activity. Dihydroauroglaucin and physcion were able to completely inhibit the replication of Influenza A virus, while neoechinulin completely inhibited Herpes Simplex Virus 1. Finally, the last series of bioassays aimed to face the urgent need of environmentally friendly antifouling and highlighted several molecules already active at extremely low concentrations, inhibiting the adhesion and growth of both bacteria and microalgae. As result, a mix of few compounds produced by E. chevalieri MUT 2316 would inhibit all the bacteria and microalgae tested. In conclusion, this Ph.D. project highlighted the outstanding biodiversity and chemodiveristy of marine fungi inhabiting sponges. The molecules isolated from E. chevalieri MUT 2316 found applications in different research fields and represent promising candidates for the development of new drugs and antifouling paints
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Duff, David A. „Wireless applications for Marine Air Ground Task Forces“. Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA311891.

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Thesis (M.S. in Systems Technology [Command, Control, Communications (C3)]) Naval Postgraduate School, June 1996.
Thesis advisor(s): W.G. Kemple, Carl R. Jones. "June 1996." Includes bibliographical references. Also available online.
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13

Chon, Suet-ling, und 莊雪玲. „Remote sensing applications in studying marine biological processes“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31255826.

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14

Jarry, Elouan. „Assessment of adhesively bonded connections for marine applications“. Thesis, University of Southampton, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418061.

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15

Yee, Swee Li Maxine. „Silver-based nanocomposite materials for marine antifouling applications“. Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/45513/.

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Biofouling of marine surfaces is an age-old problem that affects natural and man-made surfaces exposed to the aquatic environment. The tenacious attachment of seaweed and invertebrates to man-made surfaces, notably on ship hulls, has incurred undesirable economic losses. The initial stage of the biofouling process has been attributed to the attachment of marine bacteria and their subsequent formation of biofilm which attract the settlement of larger sessile organisms including barnacles and seaweed. Silver nanostructured materials have a well-documented history as antimicrobial agents against pathogenic bacteria due to their ability to penetrate cell walls and interfere with crucial cellular processes. However, there is a surprising lack of information on their activity against marine biofilm bacteria that have critical roles in the initiation of marine fouling processes. This PhD project explores the antifouling properties of novel silver nanocomposite materials as potent antifouling agents against targeted organisms present in marine environments. The study consists of the syntheses of novel silver nanocomposite materials using various templates/matrices such as ion-exchange polymeric microspheres, zeolites, TiO2 nanotubes and graphene nanosheets. These materials were characterized through various instrumentation techniques including scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray powder diffraction (XRD), UV-visible (UV-vis) spectrophotometry, transmission electron microscopy (TEM), accelerated surface area porosimetry (ASAP), thermal gravimetric analysis (TGA), and Raman spectroscopy to elucidate their physical properties. Their antifouling effects were evaluated on Halomonas pacifica, a model marine microfouling bacterium, through an established static biofilm assay. In addition, the biological effects of these silver nanocomposites were also studied on marine microalgae Dunaliella tertiolecta and Isochrysis sp. Silver-polymer nanocomposite (Ag-PNC) microspheres were formed through a rapid chemical synthesis procedure at room temperature via the reduction of silver nitrate by sodium borohydride. The introduction of Ag nanoparticles (AgNPs) enhanced the thermal stability of the Dowex microspheres by shifting the glass transition temperature to above 300°C and the material decomposition occurred above 460°C. XRD analysis confirmed the presence of metallic Ag, while UV-vis absorption studies showed the characteristic surface plasmon resonance (SPR) for AgNPs ranging from 406 – 422 nm maximum absorption wavelengths. SEM imaging revealed the uniform distribution of AgNPs with diameters between 20 – 60 nm on the surface of the microbeads. The Ag-PNC materials, diluted to a concentration of 1 mg/mL in marine broth, showed a potent inhibitory effect on H. pacifica biofilm formation, with up to 76% decrease of biofilm when contrasted with the polymeric microspheres without Ag. Ag-PNCs also caused significant growth inhibition of D. tertiolecta and Isochrysis sp. Silver-zeolite nanocomposite clusters (AgZ) were formed through a low temperature chemical reduction method using the environmentally friendly trisodium citrate. The stable and porous inner structure of ZSM-5 zeolites performed a dual role as a stable size-control template and a reservoir of antimicrobial nanosilver. SEM revealed the globular and cluster-like morphology of the AgZ composites, with a homogenous distribution of silver particles on the surface of the clusters. EDX results displayed an increasing Ag loading with higher concentrations of Ag precursor, up to 10 wt% Ag. The UV-visible absorption displayed the characteristic SPR absorption maximum ranging from 408 – 500 nm. The AgZ clusters with metallic silver loading of up to 10 wt% Ag, diluted to a concentration of 1 mg/mL, reduced H. pacifica biofilm attachment of up to 81% compared to pure zeolite alone. XRD analysis clearly indicated the presence of metallic Ag while the ZSM-5 zeolite crystalline framework remained largely intact after the Ag crystal growth process. Brunauer-Emmett-Teller (BET) analysis showed a reduction in surface area of up to 44% with the incorporation of AgNPs into the zeolite, indicating the formation and growth of Ag within the internal pores and channels of the zeolite. Although the introduction and crystal growth of silver nanoparticles within the porous structure of the zeolite caused a change from a mesoporous to a largely macroporous structure, the integrity of the zeolite template was preserved. Silver-titania nanotube (Ag/TNT) composite material was prepared through a novel 2-step hydrothermal synthesis method. Titania nanotubes were chosen as a support material for the AgNPs as its greater specific surface area on the inner and outer surfaces of its tubular structure lead to enhanced properties. The morphology, particle size, chemical content, crystal structure, optical properties and surface area were systematically characterized. Determination of biofilm inhibitory properties revealed that Ag/TNT (concentration of 0.1 mg/mL) with the lowest silver content (0.95 wt% Ag) decorated with AgNPs of approximately 3 nm reduced biofilm formation of H. pacifica by 98% compared to pure titania nanotubes and bulk silver alone. Growth inhibition of D. tertiolecta and Isochrysis sp. were also observed. Interestingly, the antifouling properties were improved with a size decrease of AgNPs. The work shows that titania nanotubes are a stable and effective support for the anchoring and growth of AgNPs. The addition of very low amounts of Ag enhanced the antifouling property of pure TiO2 to produce an extremely potent antifouling effect on the targeted organisms. Graphene-Ag (GAg) nanocomposites were prepared from a novel and mild hydrothermal synthesis method which bypasses the formation of graphene oxide. The GAg nanocomposite combines the antimicrobial property of silver nanoparticles and the unique structure of graphene as a support material, with potent marine antifouling properties. The results show that GAg nanocomposites displayed significant biofilm inhibition property on H. pacifica and antiproliferative effects on D. tertiolecta and Isochrysis sp. As low as 1.3 wt% of Ag loading on a GAg sample, diluted to a concentration of 0.1 mg/mL, inhibited biofilm formation from H. pacifica. The GAg sample with 4.9 wt% Ag loading was associated with a biofilm inhibition of 99.6%. The marine antifouling properties of GAg nanocomposites were a synergy of the biocidal AgNPs anchored on the flexible graphene sheets, thereby providing maximum active contact surface areas to the target organisms. The GAg material was characterized with SEM, EDX, TEM, XRD and Raman spectroscopy. In addition, the GAg material exhibited the surface-enhanced Raman scattering (SERS) effect. The AgNPs were estimated to be between 72-86 nm, observed supported on micron-scaled graphene flakes. These results strongly suggest that the 4 types of silver-based nanocomposite materials are promising marine antifouling agents. The addition of very low amounts of Ag enhanced the antifouling property of the support structure, and the nanocomposites were shown to be more effective on the targeted organisms compared to the matrix material or bulk silver alone. In addition, the precursor materials used in the syntheses are affordable and easily available, whilst the synthetic methods and conditions are facile, environmentally friendly, and capable of producing high yields.
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Scott-Murray, Amy. „Applications of 3D computational photography to marine science“. Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=233937.

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This thesis represents the first dedicated study of the application of computational photography in marine science. It deals chiefly with the acquisition and use of photogrammetrically derived 3D organism models. The use of 3D models as 'virtual specimens' means that they may be securely archived and are accessible by anyone in any part of the world. Interactive 3D objects enhance learning by engaging the viewer in a participatory manner, and can help to clarify features that are unclear in photographs or diagrams. Measurements may be taken from these models for morphometric work, either manually or in an automated process. Digital 3D models permit the collection of novel metrics such as volume and surface area, which are very difficult to take by traditional means. These, and other metrics taken from 3D models, are a key step towards automating the species identification process. Where an organism changes over time, photogrammetry offers the ability to mathematically compare its shape before and after change. Sponge plasticity in response to stress and injury is quantified and visualised here for the first time. An array of networked underwater cameras was constructed for simultaneous capture of image sets. The philosophy of adapting simple, cheap consumer hardware is continued for the imaging and quantification of marine particulates. A restricted light field imaging system is described, together with techniques for image processing and data extraction. The techniques described are shown to be as effective as traditional instruments and methods for particulate measurement. The array cameras used a novel epoxy encapsulation technique which offers significant weight and cost advantages when compared to traditional metal pressure housings. It is also described here applied to standalone autonomous marine cameras. A fully synchronised autonomous in situ photogrammetry array is now possible. This will permit the non-invasive archiving and examination of organisms that may be damaged by recovery to the surface.
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Ljungberg, Fredrik. „Estimation of Nonlinear Greybox Models for Marine Applications“. Licentiate thesis, Linköpings universitet, Reglerteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165828.

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As marine vessels are becoming increasingly autonomous, having accurate simulation models available is turning into an absolute necessity. This holds both for facilitation of development and for achieving satisfactory model-based control. When accurate ship models are sought, it is necessary to account for nonlinear hydrodynamic effects and to deal with environmental disturbances in a correct way. In this thesis, parameter estimators for nonlinear regression models where the regressors are second-order modulus functions are analyzed. This model class is referred to as second-order modulus models and is often used for greybox identification of marine vessels. The primary focus in the thesis is to find consistent estimators and for this an instrumental variable (IV) method is used. First, it is demonstrated that the accuracy of an IV estimator can be improved by conducting experiments where the input signal has a static offset of sufficient amplitude and the instruments are forced to have zero mean. This two-step procedure is shown to give consistent estimators for second-order modulus models in cases where an off-the-shelf applied IV method does not, in particular when measurement uncertainty is taken into account. Moreover, it is shown that the possibility of obtaining consistent parameter estimators for models of this type depends on how process disturbances enter the system and on the amount of prior knowledge about the disturbances’ probability distributions that is available. In cases where the first-order moments are known, the aforementioned approach gives consistent estimators even when disturbances enter the system before the nonlinearity. In order to obtain consistent estimators in cases where the first-order moments are unknown, a framework for estimating the first and second-order moments alongside the model parameters is suggested. The idea is to describe the environmental disturbances as stationary stochastic processes in an inertial frame and to utilize the fact that their effect on a vessel depends on the vessel’s attitude. It is consequently possible to infer information about the environmental disturbances by over time measuring the orientation of a vessel they are affecting. Furthermore, in cases where the process disturbances are of more general character it is shown that supplementary disturbance measurements can be used for achieving consistency. Different scenarios where consistency can be achieved for instrumental variable estimators of second-order modulus models are demonstrated, both in theory and by simulation examples. Finally, estimation results obtained using data from a full-scale marine vessel are presented.
I takt med att marina farkoster blir mer autonoma ökar behovet av noggranna matematiska farkostmodeller. Modellerna behövs både för att förenkla utvecklingen av nya farkoster och för att kunna styra farkosterna autonomt med önskad precision. För att erhålla allmängiltiga modeller behöver olinjära hydrodynamiska effekter samt systemstörningar, främst orsakade av vind- och vattenströmmar, tas i beaktning. I det här arbetet undersöks metoder för att skatta okända storheter i modeller för marina farkoster givet observerad data. Undersökningen gäller en speciell typ av olinjära modeller som ofta används för att beskriva marina farkoster. Huvudfokus i arbetet är att erhålla konsistens, vilket betyder att de skattade storheterna ska anta rätt värden när mängden observerad data ökar. För det används en redan etablerad statistisk metod som baseras på instrumentvariabler. Det visas först att noggrannheten i modellskattningsmetoden kan förbättras om datainsamlingsexperimenten utförs på ett sätt så att farkosten har signifikant nollskild hastighet och instrumentvariablernas medelvärde dras bort. Den här tvåstegslösningen påvisas vara fördelaktig vid skattning av parametrar i den ovan nämnda modelltypen, framför allt då mätosäkerhet tas i beaktning. Vidare så visas det att möjligheten att erhålla konsistenta skattningsmetoder beror på hur mycket kännedom om systemstörningarna som finns tillgänglig på förhand. I fallet då de huvudsakliga hastigheterna på vind- och vattenströmmar är kända, räcker den tidigare nämnda tvåstegsmetoden bra. För att även kunna hantera det mer generella fallet föreslås en metod för att skatta de huvudsakliga hastigheterna och de okända modellparametrarna parallellt. Denna idé baserar sig på att beskriva störningarna som stationära i ett globalt koordinatsystem och att anta att deras effekt på en farkost beror på hur farkosten är orienterad. Genom att över tid mäta och samla in data som beskriver en farkosts kurs, kan man således dra slutsatser om de störningar som farkosten påverkas av. Utöver detta visas det att utnyttjande av vindmätningar kan ge konsistens i fallet med störningar av mer generell karaktär. Olika scenarion där konsistens kan uppnås visas både i teori och med simuleringsexempel. Slutligen visas också modellskattningsresultat som erhållits med data insamlad från ett fullskaligt fartyg.
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Beres, Miloslav. „Welding of thin sheet steels in marine applications“. Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6050.

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Many metal structures are assembled from thin plate with welded supports for stiffness to resist local loadings. However, welded joints, which require large heat input, may incur significant distortion in the finished plate. Although the causes of distortion are known, and have been the focus of number of studies, there is still a lack of fundamental understanding of process and physical parameters in causing distortion. The overall aim of this work is to identify the interaction of process and physical parameters in causing distortion of welded ferritic thin steel plates. Experimental measurements and the finite element method are used to identify the relationship between distortion and the influence of pre-existing (residual) stresses in the plates. Effect of onset of transformation temperature on distortion is examined. An improved comprehension of the mechanisms causing distortion, and a readily useable model to explore alternatives has significant potential in wide range of industries and thus is a major driving force for continued research. The ability to predict with reasonable certainty the geometry of distortion will enable users to evaluate alternative design and production parameters. The work is divided into eight chapters: The first chapter gives an introduction and lists the objectives of the research. A theoretical exploration of the problem in addition to a survey of relevant work with regard to the welding of ferritic steels, weld microstructures, residual stresses, finite element modelling (FEM) and an overview of experimental techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), neutron diffraction (ND) is given in chapter 2. In chapter 3 experimental investigation results including both post-weld and in-situ microstructure observation and residual stress distribution are presented and discussed [1, 2]. To provide a qualitative insight into fundamental understanding of development of residual stress, a finite element model that considers both the thermal and the transformation strains caused by solid-state phase transformation was developed and is presented in the chapter 4 [3]. A validated finite element model for computation of residual stresses is presented in the chapter 5 [4]. Special emphasis was placed on the effect of transformation temperature on residual stress development in both the actual weld and the model. Most of the modelling results were validated against experimental measurements. Chapter 6 presents a sensitivity study on the effect of parameter changes on distortion. An attempt was made to elucidate both the effect of transformation start temperature and the initial distortion on the final distortion [5]. Chapter 7 details application of a model for variant selection [6], which is based on work published in [7, 8] to actual welds. This work was performed to elucidate the effect of texture on residual stress. Finally the last chapter draws together the major conclusions of the thesis, and suggests future avenues of investigation to progress the research discussed here.
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BERTHET, CRISTELE. „Ecoulement et transport littoraux tridimensionnel : applications numeriques“. Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10223.

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L'utilisation d'un modele numerique tridimensionnel a permis d'etudier d'une part un ecoulement caracteristique en zone cotiere a forte bathymetrie, d'autre part, le transport de sediment. L'influence de la bathymetrie et de la stratification sur l'evolution d'un courant et de la surface libre est analysee. Cette etude se concretise par une simulation realiste de la section du courant nord face a la baie de monaco. Le transport du sable et de la vase est considere sous l'action d'un courant et de la houle. Puis, une etude sur le transport des particules organique permet d'evaluer la production primaire dans la colonne d'eau
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Zimmerman, Joseph S. „Business wargaming applications for Marine Corps Manpower policy decisions /“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA378665.

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Thesis (M.S. in Management) Naval Postgraduate School, March 2000.
Thesis advisor(s): Dolk,Daniel R. ; Filizetti, Julie. "March 2000." Includes bibliographical references (p. 83-86). Also available in print.
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Quinn, Rory. „Marine high-resolution reflection seismology : acquisition, processing and applications“. Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243092.

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22

Abdelbagi, Hamdi Eltayib. „FPGA-Based Coherent Doppler Processor for Marine Radar Applications“. University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1461182845.

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23

Purves, Glenn Timothy. „Economic aspects of AES marine weather services in marine applications, a case study of Atlantic Canada“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24897.pdf.

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24

Fernandez-Gonzalez, Victoria. „Fouling amphipods on marine aquaculture facilities: ecological interactions and potential applications and potential applications“. Doctoral thesis, Universidad de Alicante, 2017. http://hdl.handle.net/10045/89091.

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Aquaculture facilities involve mooring a large amount of artificial structures in offshore areas, which are colonised by a wide group of marine organisms, forming characteristic fouling communities. Many studies have focused on determining what sessile organisms are able to settle on nets, ropes and buoys, owing to the specific problems they cause and their economic cost to the aquaculture industry. Although sessile fouling communities are well-studied from the point of view of controlling this community on aquaculture facilities, little is known about the epifaunal mobile species inhabiting these artificial structures. This thesis addresses the study of crustacean amphipods, which have been scarcely studied regarding their species composition and relation to the habitats created by the sessile species and despite being detected in high abundances. After the general introduction, which sets the study framework, Chapter 1 is a preliminary study on the composition of fouling assemblages on aquaculture facilities in the Mediterranean Sea, comparing them with others such as those in harbours or offshore structures. Therein, it is shown that fouling communities are made up of mainly bivalves, algae, hydroids and bryozoans and amphipods usually represent more than 80 % of motile fauna associated with these organisms. Moreover, amphipod assemblages are characterised by seven frequent and dominant species: Elasmopus rapax, Jassa marmorata, Jassa slatteryi, Ericthonius punctatus, Stenothoe tergestina, Caprella equilibra and Caprella dilatata. A quantitative study of amphipod densities is carried out in Chapter 2, where mean amphipod densities observed in fish farm fouling amounted to 176,000 ind.m-2 and reached maxima up to 1,000,000 ind.m-2. There, the role of the macro- and microhabitat in supporting such amphipod communities is explored. The effect of the modification of marine currents on pelagic communities due to the introduction of coastal infrastructures is analysed in Chapter 3. Therein, it was detected a retention effect on planktonic amphipods near such facilities, noticeable in the increased abundance of hyperiids and migrating amphipods from different benthic and floating habitats. The influence of fouling amphipods on other habitats is analysed in Chapters 4 and 5, it is shown that fish-farm fouling acts as a source population of amphipods dispersing towards both defaunated sediments in soft-bottoms and surrounding floating habitats. Finally, in the last chapter, based on the possibility of using wild fauna already growing in fish farms, the applicability of amphipods as an accessory culture is tested in an offshore integrated multi-trophic aquaculture (IMTA) system with finfish as main fed species. Throughout this thesis it has been shown that fish-farming activities affect the amphipod assemblage in several ways such as the establishment of high population densities or the intimate connectivity between different subpopulations. As a result, a new potential commercial application arises from the possibility of using them as biofilters of aquaculture wastes, within an off-coast integrated multitrophic aquaculture system, promoting a more sustainable development of aquaculture in the marine environment.
Las estructuras artificiales que conforman las instalaciones de acuicultura en mar abierto suelen ser colonizadas por multitud de organismos marinos, que forman comunidades de fouling características en estas estructuras. Muchos estudios se han centrado en la descripción de los organismos sésiles que se desarrollan sobre cabos, redes y boyas de las instalaciones de acuicultura, debido a los problemas que generan para el cultivo y los costes adicionales que significan para la industria derivados de su necesaria eliminación. Sin embargo, aunque las comunidades de fouling sésiles han sido bien estudiadas desde el punto de vista de su control en las instalaciones de acuicultura, poco se sabe sobre la epifauna que habita estas estructuras artificiales. Esta tesis se centra en el estudio de los crustáceos anfípodos, los cuales aún no han sido estudiados en cuanto a la composición de especies y a su relación con los hábitats creados por los organismos sésiles, a pesar de haber sido detectados en grandes abundancias en las instalaciones de acuicultura. Después de una introducción general, que establece el marco de estudio, el capítulo uno es un estudio preliminar sobre las comunidades de fouling de las instalaciones de acuicultura en el Mediterráneo, comparándolas con las desarrolladas en otras estructuras artificiales como puertos o plataformas petrolíferas. En este capítulo, se demuestra que las comunidades de fouling están compuestas principalmente por bivalvos, algas, hidrozoos y briozoos y que más de un 80% de la fauna asociada a estos organismos son anfípodos. Además el poblamiento se caracteriza por la presencia de siete especies de anfípodos que son frecuentes y abundantes: Elasmopus rapax, Jassa marmorata, Jassa slatteryi, Ericthonius punctatus, Stenothoe tergestina, Caprella equilibra y Caprella dilatata. Un estudio cuantitativo de las densidades de estos anfípodos se lleva a cabo en el capítulo 2, donde se encuentra que la densidad media es de 176.000 ind.m-2, con máximos de más de 1.000.000 ind.m-2. Allí se explora también el papel de los macro y microhábitats en mantener dichas poblaciones de anfípodos. El efecto de la modificación de corrientes sobre las comunidades plantónicas debida a la instalación de las piscifactorías se analiza en el capítulo 3. En él, se detectó una retención de los anfípodos planctónicos cerca de las instalaciones, evidenciada por el incremento en las abundancias de hipéridos y de anfípodos migradores desde diferentes hábitats bentónicos flotantes. La influencia de las grandes densidades de anfípodos del fouling sobre otros hábitats se estudia en los capítulos 4 y 5, donde se observó que el fouling actúa como fuente de anfípodos migradores, exportando individuos que colonizan tanto sedimentos defaunados en el fondo marino como otros hábitats flotantes cercanos. Finalmente, en el último capítulo se analiza la posibilidad de aprovechar la producción natural y la conectividad observadas a través del cultivo de anfípodos como parte de un sistema de acuicultura multitrófica integrada (AMTI) en mar abierto con peces como especie principal. A lo largo de esta tesis, se demuestra que la acuicultura influencia las poblaciones de anfípodos marinos, tanto en el establecimiento de grandes densidades de población como en la conectividad entre las diferentes subpoblaciones. Como resultado, surge una nueva aplicación comercial de la posibilidad de usar los anfípodos del fouling como biofiltros, reciclando los residuos de la acuicultura dentro de un sistema de acuicultura multitrófica, garantizando así un desarrollo más sostenible de la acuicultura en el medio marino.
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Yeung, Chung-hang. „Magnetic properties of seabed sediments in Hong Kong : applications to sedimentological and contamination studies /“. Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20567662.

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Flournoy, Mark A. „Benefits of multicasting applications within the United States Marine Corps“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA366759.

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Thesis (M.S. in Information Technology Management) Naval Postgraduate School, June 1999.
"June 1999". Thesis advisor(s): Syed Ali, Terrance Brady. Includes bibliographical references (p. 73-74). Also avaliable online.
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Schenkels, William H. „Development of thin section concrete for marine and aquaculture applications“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/MQ35524.pdf.

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28

See, Seng Chai. „Development & characterisation of novel nano-gelcoat for marine applications“. Thesis, University of Portsmouth, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494002.

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Gelcoats are required to improve the durability of boat hulls, protect the laminate from environmental assault and provide a smooth aesthetic surface finish thus giving significant added value. The material employed for this application needs to exhibit high specific stiffness, strength and toughness, excellent surface quality and cost effectiveness. Unfortunately, conventional gelcoat systems are far from being satisfactory and improvements are needed to meet the diverse requirements of marine product customers.
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Boinard, Eric. „Influence of water on polymeric materials used in marine applications“. Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.654947.

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Pretheesh, Paul C. „Strength and reliability of thin walled structures for marine applications“. Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=16776.

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31

Xu, G. „Numerical simulation of two-dimensional vortex shedding for marine applications“. Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1398681/.

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The velocity potential theory has been adopted to investigate the two-dimensional vortex shedding problems in marine hydrodynamics. The theory can find its applications to the lifting body problems such as a hydrofoil advancing near the free surface, the flow passing through an orifice of a damaged compartment, the vortex shedding at sharp edges of a marine structure. Since the viscosity of the fluid is assumed to be confined within a thin boundary layer along the surface of the structure, the fluid flow can be described by velocity potential theory. Literature review on vortex shedding has been presented. The development of relevant theories and their applications have been discussed. The challenges and suitable methodologies are investigated. When the steady motion and small amplitude unsteady motion of a hydrofoil advancing near free surface is considered, a flat vortex sheet is introduced and imposed behind the trailing edge; linear free surface conditions are imposed to study the free surface effects. Free surface Green functions, which satisfy free surface boundary conditions, are adopted to account for the free surface effects which are found to be highly significant. To study the non-linear effects of body surface boundary condition and vortex wake when the attack angle or the motion amplitude becomes moderately large, we introduce a time stepping scheme. The vortices shed from the trailing edge are approximated by introducing point vortex. The non-linear effects of body surface condition and vortex wake are investigated. Further studies on the submerged foil and surface piercing structures with vortex shedding are presented; efforts are made to investigate the non-linear wave-body interaction problems with vortex shedding. The non-linear free surface and non-linear vortex wake are found to have significant effects on the fluid flow and the hydrodynamic force.
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Östling, Erik. „Model on degradation of PEM fuel cells in marine applications“. Thesis, KTH, Kemiteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299446.

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Sjöfarten står för 3 % av världens totala växthusgaser och är idag högst beroende av fossila bränslen. Ett alternativ för att gå över till en fossilfri flotta är användning av bränsleceller och vätgas som drivmedel. Om vätgasen produceras från elektrolys med förnyelsebara energikällor så är driften utsläppsfri och koldioxidneutral. Bränsleceller kan användas i många olika sammanhang, men har ännu inte slagit igenom med full kraft. En anledning till detta är livslängden som är för kort. För att sjöfarten ska kunna implementera bränslecellsdrift behöver nedbrytningen av bränslecellen bli vidare utforskad och motverkad. Syftet med detta examensarbete var att hitta de mest signifikanta nedbrytningsmekanismerna för sjöfarten samt att bygga en modell för att förutspå livslängden utifrån lastprofiler från fartyg.  Rapportens avgränsningar var att enbart studera PEM-bränsleceller tack vare dess höga energitäthet och att teknologin är närmast marknaden för mobila applikationer. En litteraturstudie genomfördes för att fastställa de viktigaste nedbrytningsmekanismerna samt de faktorer som begränsar livslängden. Dessa bestämdes till start/stop cykler samt lastcykler vilka försämrar konduktiviteten i membranet samt minskar den elektrokemiska ytarean. En empirisk modell från experiment från litteraturen etablerades för att hitta relationen mellan parametrarna konduktivitet och elektrokemisk ytarea som funktion av start/stop cykler respektive lastcykler. En Comsol-modell användes för att utvärdera bränslecellens prestanda med dessa försämrade parametrar. Två lastprofiler analyserades och tolkades som antal start/stop cykler samt lastcykler för att utvärdera prestandan som funktion av antal år i drift. Båda fallen var i drift till dess att prestandan minskat med 20 % utvärderat vid strömtätheten 0.6 A/cm2. Båda lastprofilerna var utvärdera med olika körstrategier för att jämföra den modellerade livslängden beroende på ingångsvärden. Den första lastprofilen delades in i Case 1a och Case 1b där antalet start/stop cykler och lastcykler varierade. Resultatet visade att antalet timmar i drift mer än tredubblades i Case 1b där båda ingående indata hade minskats.   Case 2 delades upp i tre olika körstrategier där Case 2a var en referens som jämfördes mot Case 2b respektive Case 2c. Skillnaden mot Case 2b var att antalet start/stop cykler per dag multiplicerades med faktor 4. Resultatet från modellen var att livstiden minskade från 6 till 4 år. Vidare utvärderades Case 2c där istället antalet lastcykler dividerades med faktor 4, allt annat identiskt med Case 2a. Utfallet var en ökad livslängd från 6 år till 11 år, med totalt 32 032 timmar i drift. Denna livslängd kan jämföras med kommersialiserade marina produkter från Ballard och Powercell, där livslängden är 30 000 respektive 20 000 timmar i drift.  Sammanfattningsvis kan det konstateras att både start/stop cykler och lastcykler bryter ner bränslecellen och därmed minskar dess prestanda. Lastcykler var den faktor som var mest förödande gällande livslängden. Den modellerade livslängden på 32 032 timmar indikerar att den empirisk modellen tillsammans med Comsol-modellen genererade realistiska resultat. Slutligen kan sägas att ett område för framtida forskning inom ämnet innefattar lastcykler eftersom denna hade störst påverkan på modellen. Att särskilja olika typer av lastcykler och koppla till olika degradering skulle skapa än mer förståelse för livslängden. Då denna studie genomfördes på bränslecellsnivå skulle framtida studier kunna inkludera att analysera degradering på systemnivå för att få mer insikt i dessa processer.
The shipping industry emits 3 % of the global GHG-emissions and is highly dependent on fossil fuels. One alternative to decarbonise the sector is by utilising hydrogen in fuel cells. The propulsion is free from emissions if hydrogen is produced from renewables. The fuel cell technology can be applied in various applications but have not been fully commercialised. One of the biggest bottlenecks for fuel cell technology is the durability that needs to be improved. In order for marine vessels to implement hydrogen propulsion, the degradation need to be further understood and mitigated. The purpose of this thesis was to assess the most significant degradation mechanisms for marine applications and to build a model to evaluate the lifetime depending on load profiles. The scope of the thesis was to include PEMFCs since they have the highest power density and are closest to commercialisation for transport applications. A literature review was conducted to assess the most important degradation mechanisms and operating conditions that limits the lifetime, which concluded in start/stop cycling and load cycling. These conditions deteriorate the membrane conductivity and the electrochemical surface area. An empirical model based on experimental data from the literature was conducted to find relationships for conductivity and ECSA as function of start/stop cycling and load cycling, respectively. A Comsol model was established to evaluate performance reduction with degraded parameters. Two different load cycles were interpreted as number of start/stop cycles and load cycles in order to simulate the degradation. The output was polarization curves as function of operating years. Each case was operated until a performance reduction of 20 % was obtained at the current density of 0.6 A/cm2.  Both load profiles were analysed with different operation strategies to compare the resulting lifetime. The first load curve was divided into Case 1a and Case 1b where start/stop cycles and load cycles were altered. The results showed that the lifetime in operation hours was more than three-folded in Case 1b when the number of start/stop cycles and load cycles was reduced.  Case 2 was divided into three operating strategies. For comparison with Case 2a, the number of start/stop cycles per day in Case 2b was increased by a factor of 4. The result was that the lifetime declined from 6 to 4 years. Furthermore, Case 2c evaluated the lifetime if the number of load cycles per day decreased by a factor of 4, all else being equal to Case 2a. The outcome was an increment in lifetime from 6 to 11 years, with a total of 32 032 hours of operation. This lifetime can be compared to commercialised products from Ballard and Powercell with lifetimes of 30 000 and 20 000 operating hours, respectively. Conclusively, the simulations showed that both start/stop cycling and load cycling deteriorates the fuel cell performance. Load cycling is the operating condition that cause the most severe degradation. Moreover, the modelled lifetime of 32 032 hours indicates that the empirical model in combination with the Comsol model generate realistic lifetimes. Finally, since load cycling had the most vital impact on the lifetime, one of the topics for future research would be to distinguish different types of load cycles and connect to separate degradation outcomes. Since the model was on fuel cell level, future work could also include systems effects such as ripple current or distributions within fuel cell stacks.
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San, Baogang. „Dynamic modelling of SOFC marine power systems and shipboard applications“. Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=23156.

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Sustainable and efficient provision of shipboard energy is an obvious challenge for the merchant marine industry. Various initiatives have been made to find alternatives to replace the currently used combustion engine for ship power and propulsion. In recent years, fuel cell technology, as has been widely advertised as a clean and efficient means of power generation, is drawing much attention from the marine industry. Among various types of fuel cells, the Solid Oxide Fuel Cell (SOFC) tops others in terms of energy conversion efficiency as it can be fed with both hydrogen rich fuels and traditional fossil fuels after being chemically reformed. These features make it most promising to meet the large power demands of seagoing ships. However, due to the comprehensive and hazardous working environment, shipboard installation of SOFC power systems is not available. Can the SOFC be a viable proposition for commercial shipping and how will it behave under severe seagoing circumstances? These questions need to be addressed before commercialising SOFC marine power systems. In the thesis, simulation methods are used to predict the performance of marine SOFC systems at both static and dynamic working loads. A mathematical model is developed for describing the thermodynamic nature of a tubular SOFC concerning the thermal equilibrium of the system. Electric-chemical reactions are reflected in the stack modelling. Reforming reactions of the fuel are included in the model. Auxiliary subcomponents within the SOFC power system are modelled based on their own mechanisms and working principles. The whole simulation system is composed by combining subcomponent models via reasonable control strategies to function the system's purpose. SOFC power system models are developed to represent different working scenarios which may possibly occur onboard ship. The dynamic responses of simulation systems are examined. Thermal flow transfer influence, manifold volume influence and controller 's influence are also taken into account in the dynamic modelling process. As concluded from the simulation outcomes, the sample SOFC system, while running alone, could satisfy the demand of dynamic load change for both propulsion and auxiliary power. However, the electric output of the SOFC system would be greatly smoothed if paralleled with a battery. In addition, risk and safety issues regarding SOFC onboard installation are examined from both design and operating perspectives. Relevant ship rules and regulations for verifications of system installation and maintenance are reviewed in detail. Conceptual design of marine SOFC application are also proposed at the last stage.
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Götz, Thomas. „Aversiveness of sound in marine mammals : psycho-physiological basis, behavioural correlates and potential applications“. Thesis, St Andrews, 2008. http://hdl.handle.net/10023/848.

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Busetti, Alessandro. „Isolation of novel marine-derived bioactive agents for medical device applications“. Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669664.

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Ireland were screened for the production of antimicrobials and quorum sensing inhibitors. (QSIs). 37 bacterial isolates were found to inhibit QS-dependent pigment production in Chromobacterium violaceum ATCC12472 or Serratia sp ATCC39006. The organic extracts of five isolates caused a significant decrease in both total biomass and biofilm viable counts displaying a range of growth inhibitory and antimicrobial activities. All five organic extracts caused a reduction in Pyocyanin production while three extracts significantly decreased the production of Pyoverdin in P. aeruginosa PAOI. The ability of the algae Bonnemaisonia hamifera and Halidrys siliquosa to produce antibiofilm bioactives was also investigated. Algal extracts of B. hamifera had varying degrees of antibiofilm activity on P. aeruginosa PAOl, E. coli ATCCl1303 and P. mirabilis ATCC7002. The antibiofilm activity of the chloroform, acetonitrile, and hexane extracts was found to be consistent with the presence of QSls detected using both, QSI reporter strain C. violaceum A TCC 12472 and with the luminescence-based bioreporter strains E. coli JMI09 pSB 1142 and JM 109 pSB536 suggesting a QSI -dependent mechanism. The methanolic extract of the alga H. siliquosa failed to display any QSI activity but was found to possess a broad-spectrum antimicrobial activity against bacteria belonging to the genus Staphylococcus, Streptococcus, Enterococcus and Propionibacterium with MBEC values of 1.25 mg/ml for both S. aureus (MRSA) 33593 and P. acnes lA. Bioassay-guided fractionation of the extract allowed the isolation of three compounds displaying antimicrobial and antibiofilm activity against MRS A ATCC33593. The molecular weights of the compounds was determined by UPLCqTOF- MS (442, 442 and 428 m/z respectively) and found to differ from the meroditerpenoids previously extracted from this alga {{902 Culioli,G. 2008;}}. The MBEC values of MRSA ATCC33593 were 0.028mg/ml (64/lM) for compounds 1 & 2 and 0.055 mg/ml (128 /uM) for compound 3. Structural elucidation of the three antimicrobials is currently underway in collaboration with Prof. Tasdemir, NUIG, Galway.
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Nejjar, Nabih. „Utilisation du propagateur en traitement d'antenne : applications en acoustique sous-marine“. Grenoble INPG, 1991. http://www.theses.fr/1991INPG0055.

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Le traitement d'antenne passif cherche a caracteriser des sources rayonnantes (nombre, puissance, position geographique, amplitude complexe. . . ). Nous developpons, en premier lieu, des methodes matricielles de localisation a haute resolution dont la recente approche du propagateur. Differentes methodes d'estimation de la matrice spectrale sont discutees en introduisant les notions de moyennes temporelles et frequentielles. Ce traitement, applique a des donnees experimentales d'acoustique sous-marine, permet d'estimer les deformations d'une antenne tres longue ainsi que la distribution des gains complexes des capteurs. En second lieu, nous developpons la methode du propagateur monocoup a diversite d'espace utilisant directement les donnees recues en frequence sur les differents capteurs. Les conditions de validite sont discutees et nous presentons une application a des signaux d'acoustique sous-marine en presence de trajets multiples
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Ulrich, Robert Michael. „RNA Detection Technology for Applications in Marine Science: Microbes to Fish“. Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5321.

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The accurate identification of taxa from mixed assemblages using genetic analysis remains an important field of molecular biology research. The common principle behind the development of numerous documented genetic detection technologies is to exploit specific nucleotide sequences inherent to each taxon. This body of work focuses on practical applications of real-time nucleic acid sequence-based amplification (RT-NASBA) in marine science, and is presented in four case studies. Each study represents novel work in the genetic identification of respective taxa of interest using RT-NASBA. Two case studies documented the development of an assay targeting mitochondrial 16S rRNA to discern legally salable grouper species in the U.S. from fraudulently mislabeled surrogate fish. This technology was first validated using lab-based, benchtop instrumentation, and was then adapted into a complete field detection system. The third study documented an internally controlled RT-NASBA (IC-NASBA) assay for the detection and quantification of the harmful algal bloom-causing dinoflagellate, Karenia mikimotoi, by targeting the ribulose-1, 5-bisphosphate carboxylase-oxygenase (RuBisCO) large-subunit gene (rbcL). The final section of this dissertation details the preliminary development of an IC-NASBA assay targeting large subunit rRNA for the quantification of Enterococcus, which is a genus of bacteria commonly used as an indicator of fecal pollution in recreational marine water. My results show that RT-NASBA provides a suitable format for the accurate identification of target species from these taxa which include prokaryotes, as well as both unicellular and multicellular eukaryotes.
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McIntosh, Kyle Douglas. „Pharmaceutical applications and toxicity of extracted alkenones from marine Isochrysis algae“. University of Toledo Health Science Campus / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=mco1564780576118206.

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39

Lin, Tian Ran. „Vibration of finite coupled structures, with applications to ship structures /“. Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0093.

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40

Cahill, John J. „Experimental studies of noise/vibration damping for undersea warfare applications“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FCahill.pdf.

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Thompson, Phillip Allan. „Stiffened shell elements : developments and applications to perforated structures“. Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328179.

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42

Fischer, Matthias [Verfasser]. „Marine biofilm formation dynamics – from sensor development to field applications / Matthias Fischer“. Kiel : Universitätsbibliothek Kiel, 2013. http://d-nb.info/1045603961/34.

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43

Plosay, James R. „Enhanced VAX/VMS programming solutions with applications for preliminary marine vehicle design“. Thesis, Monterey, California : Naval Postgraduate School, 1990. http://edocs.nps.edu/npspubs/scholarly/theses/1990/Sep/90Sep%5FPlosay.pdf.

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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 1990.
Thesis Advisor(s): Papoulias, F. A. Second Reader: Hallock, J. F. "September 1990." Description based on title screen as viewed on December 17, 2009. Author(s) subject terms: Preliminary ship design, VAX/VMS programming, VAX graphics. Includes bibliographical references (p. 130-131). Also available in print.
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Englot, Brendan J. „Stability and robustness analysis tools for marine robot localization and mapping applications“. Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54880.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 114-118).
The aim of this analysis is to explore the fundamental stability issues of a robotic vehicle carrying out localization, mapping, and feedback control in a perturbation-filled environment. Motivated by the application of an ocean vehicle performing an autonomous ship hull inspection, a planar vehicle model performs localization using point features from a given map. Cases in which the agent must update the map are also considered. The stability of the marine robot controller and estimator duo is investigated using a pair of theorems requiring boundedness and convergence of the transition matrix Euclidean norm. These theorems yield a stability test for the feedback controller. Perturbations are then considered using a theorem on the convergence on the perturbed system transition matrix, yielding a robustness test for the estimator. Together, these tests form a set of tools which can be used in planning and evaluating the robustness of marine vehicle survey trajectories, which is demonstrated through experiment. An augmented A* kinodynamic path-planning algorithm is then implemented to search the control input space for the globally robustness-optimal survey trajectory.
by Brendan J. Englot.
S.M.
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Blättler, Clara L. „Applications of calcium isotopes in marine carbonates in the Recent and Phanerozoic“. Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:9f2ce280-c7b9-43cc-8aaf-4aaac058d350.

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The applications of calcium-isotope measurements in marine carbonates are explored in several different contexts within this thesis. As a record of global ion fluxes, seawater calcium-isotope ratios can be used as tracers for large weathering imbalances, which develop as a feedback system in response to intervals of climate change. This approach provides valuable constraints on the complex climatic and oceanographic phenomena known as the Oceanic Anoxic Events. Over much longer timescales, the calcium-isotope ratio of seawater is influenced by steady-state processes that reflect the evolution of seawater chemistry. To understand these influences, the modern calcium-isotope budget is assessed quantitatively using a compilation of marine carbonate samples, revealing several distinctive components of the carbonate burial sink that can affect the steady-state balance of the calcium cycle. Changes in the major ion composition of seawater and in the organisms that contribute to sedimentary carbonate burial are shown to contribute significantly to the geological record of seawater calcium-isotope ratios. The importance of skeletal carbonate in the calcium cycle leads to another application of calcium isotopes towards understanding biomineralization. This large and complex topic is approached with calcium-isotope data from two unique growth experiments that constrain some of the mechanisms by which biogenic aragonite acquires its geochemical signatures. This range of topics presents a diverse, but by no means exclusive, sample of the topics that are accessible for investigation through calcium-isotope analysis. The potential of this isotopic tool is demonstrated by the breadth of environments and timescales represented in this work.
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46

Eleye-Datubo, Adokiye Godwill. „Integrative risk-based assessment modelling of safety-critical marine and offshore applications“. Thesis, Liverpool John Moores University, 2005. http://researchonline.ljmu.ac.uk/5806/.

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This research has first reviewed the current status and future aspects of marine and offshore safety assessment. The major problems identified in marine and offshore safety assessment in this research are associated with inappropriate treatment of uncertainty in data and human error issues during the modelling process. Following the identification of the research needs, this thesis has developed several analytical models for the safety assessment of marine and offshore systems/units. Such models can be effectively integrated into a risk-based framework using the marine formal safety assessment and offshore safety case concepts. Bayesian network (BN) and fuzzy logic (FL) approaches applicable to marine and offshore safety assessment have been proposed for systematically and effectively addressing uncertainty due to randomness and vagueness in data respectively. BN test cases for both a ship evacuation process and a collision scenario between the shuttle tanker and Floating, Production, Storage and Offloading unit (FPSO) have been produced within a cause-effect domain in which Bayes' theorem is the focal mechanism of inference processing. The proposed FL model incorporating fuzzy set theory and an evidential reasoning synthesis has been demonstrated on the FPSO-shuttle tanker collision scenario. The FL and BN models have been combined via mass assignment theory into a fuzzy-Bayesian network (FBN) in which the advantages of both are incorporated. This FBN model has then been demonstrated by addressing human error issues in a ship evacuation study using performance-shaping factors. It is concluded that the developed FL, BN and FBN models provide a flexible and transparent way of improving safety knowledge, assessments and practices in the marine and offshore applications. The outcomes have the potential to facilitate the decision-making process in a risk-based framework. Finally, the results of the research are summarised and areas where further research is required to improve the developed methodologies are outlined.
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Tomassino, Arielle. „Méthode (tau-p) et inversion des données de sismique marine : applications à l'étude des profils Ecors 84 dans le golfe de Gascogne“. Brest, 1986. http://www.theses.fr/1986BRES2025.

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Étude effectuée à partir de données de sismique réflexion grand angle et réfraction, enregistrées à deux bateaux, fournies par l'IFP et la SNEA. Profils en mer de Norvège et dans le golfe de Gascogne. Comparaison de trois formulations de la méthode (tau-p) et inversion vitesse profondeur des données de mer de Norvège. Traitement par la méthode (tau-p) et interprétation des six profils à point commun central à la campagne "ecors-gascogne".
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Biggs, Christopher H. „Distance education : a case study with applications for DoD and the Marine Corps /“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA282898.

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Thesis (M.S. in Information Technology Management) Naval Postgraduate School, June 1994.
Thesis advisor(s): David R. Henderson, Frank J. Barrett. "June 1994." Bibliography: p. 63-65. Also available online.
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Bird, Corey D. „Investigation and suppression of multipath communication signals with applications to a marine environment“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23119.pdf.

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50

Aryawan, Wasis Dwi. „An investigation into the potential of multiple rows ducted propellers for marine applications“. Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275427.

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