950 resultados para Turner, Bradley
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This report was developed to help establish National Ocean Service priorities and chart new directions for research and development of models for estuarine, coastal and ocean ecosystems based on user-driven requirements and supportive of sound coastal management, stewardship, and an ecosystem approach to management. (PDF contains 63 pages)
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The spotted seatrout (Cynoscion nebulosus) is considered a key species relative to the implementation of the Comprehensive Everglades Restoration Plan (CERP). One of the goals of the CERP is to increase freshwater flows to Florida Bay. Increased freshwater flows can have potential positive and negative impacts on spotted seatrout populations. At low salinities, the planktonic eggs of spotted seatrout sink to the bottom and are not viable (Alshuth and Gilmore, 1994; Holt and Holt, 2002). On the other hand, increased freshwater flows can alleviate hypersaline conditions that could result in an expansion of the distribution of the early life stages of spotted seatrout (Thayer et al., 1999; Florida Department of Environmental Protection1). Thus it would be useful to develop a monitoring program that can detect changes in seatrout abundance on time scales short enough to be useful to resource managers. The NOAA Center for Coastal Fisheries and Habitat Research (NOAA) has made sporadic collections of juvenile seatrout using otter trawls since 1984 (see Powell et al, 2004). The results suggest that it might be useful to sample for seatrout in as many as eight different areas or basins (Figure 1): Bradley Key, Sandy Key, Johnson Key, Palm Key, Snake Bight, Central, Whipray and Crocodile Dragover. Unfortunately, logistical constraints are likely to limit the number of tows to about 40 per month over a period of six months each year. Inasmuch as few seatrout are caught in any given tow and the proportion of tows with zero seatrout is often high, it is important to determine how best to allocate this limited sampling effort among the various basins so that any trends in abundance may be detected with sufficient statistical confidence. (PDF contains 16 pages)
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On September 7, 2000 the National Marine Fisheries Service announced that it was reinitiating consultation under Section 7 of the Endangered Species Act on pelagic fisheries for swordfish, sharks, tunas, and billfish. 1 Bycatch of a protected sea turtle species is considered a take under the Endangered Species Act (PL93-205). On June 30, 2000 NMFS completed a Biological Opinion on an amendment to the Highly Migratory Pelagic Fisheries Management Plan that concluded that the continued operation of the pelagic longline fishery was likely to jeopardize the continued existence of loggerhead and leatherback sea turtles.2 Since that Biological Opinion was issued NMFS concluded that further analyses of observer data and additional population modeling of loggerhead sea turtles was needed to determine more precisely the impact of the pelagic longline fishery on turtles. 3,4 Hence, the reinitiation of consultation. The documents that follow constitute the scientific review and synthesis of information pertaining to the narrowly defined reinitiation of consultation: the impact of the pelagic longline fishery on loggerhead and leatherback sea turtles The document is in 3 parts, plus 5 appendices. Part I is a stock assessment of loggerhead sea turtles of the Western North Atlantic. Part II is a stock assessment of leatherback sea turtles of the Western North Atlantic. Part III is an assessment of the impact of the pelagic longline fishery on loggerhead and leatherback sea turtles of the Western North Atlantic. These documents were prepared by the NMFS Southeast Fisheries Science Center staff and academic colleagues at Duke University and Dalhousie University. Personnel involved from the SEFSC include Joanne Braun-McNeill, Lisa Csuzdi, Craig Brown, Jean Cramer, Sheryan Epperly, Steve Turner, Wendy Teas, Nancy Thompson, Wayne Witzell, Cynthia Yeung, and also Jeff Schmid under contract from the University or Miami. Our academic colleagues, Ransom Myers, Keith Bowen, and Leah Gerber from Dalhousie University and Larry Crowder and Melissa Snover from Duke University, also recipients of a Pew Charitable Trust Grant for a Comprehensive Study of the Ecological Impacts of the Worldwide Pelagic Longline Industry, made significant contributions to the quantitative analyses and we are very grateful for their collaboration. We appreciate the reviews of the stock definition sections on loggerheads and leatherbacks by Brian Bowen, University of Florida, and Peter Dutton, National Marine Fisheries Service Southwest Fisheries Science Center, respectively, and the comments of the NMFS Center of Independent Experts reviewers Robert Mohn, Ian Poiner, and YouGan Wang on the entire document. We also wish to acknowledge all the unpublished data used herein which were contributed by many researchers, especially the coordinators and volunteers of the nesting beach surveys and the sea turtle stranding and salvage network and the contributors to the Cooperative Marine Turtle Tagging Program. (PDF contains 349 pages)
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Diets of 76 species of fish larvae from most oceans of the world were inventoried on the basis of information in 40 published studies. Although certaln geographlc, size- and taxon-specific patterns were apparent, certain zooplankton taxa appeared in the diets of larvae of a variety of fish species in numerous localities. Included were six genera of calanoid copepods (Acartia, Calanus, Centropages, Paracalanus, Pseudocaianus, Temora), three genera of cyclopoid copepods (Corycaeus, Oilhona, Oncata), harpacticoid copepods, copepod nauplii, tintinoids, cladocerans of the genera Evadne and Podon, barnacle nauplii, gastropod larvae, pteropods of the genus Limacina, and appendicularians. Literature on feeding habits of these zooplankters reveals that most of the copepods are omnivorous, feeding upon both phytoplankton and other zooplankton. Some taxa, such as Calanus, Paracalanus, Pseudocalanus, and copepod nauplii appear to be primarily herbivorous, while others, such as Acartia, Centropages, Temora, and cyclopoids exhibit broad omnivory or carnivory. The noncopepod zooplankters are primarily filter-feeders upon pbytoplankton and/or bacterioplankton. Despite the importance of zooplankters in larval fish food webs, spectic knowledge of the feeding ecology of many taxa is poor. Further, much present knowledge comes only from laboratory investigations that may not accurately portray feeding habits of zooplankters in nature. Lack of knowledge of the feeding ecology of many abundant zooplankters, which are also important in larval fish food webs, precludes realistic understanding of pelagic ecosystem dynamics. (PDF file contains 34 pages.)
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The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5 degrees C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology.
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With arguably the world’s most decentralized coastal governance regime, the Philippines has implemented integrated coastal management (ICM) for over 30 years as one of the most successful frameworks for coastal resource management in the country. Anthropogenic drivers continue to threaten the food security and livelihood of coastal residents; contributing to the destruction of critical marine habitats, which are heavily relied upon for the goods and services they provide. ICM initiatives in the Philippines have utilized a variety of tools, particularly marine protected areas (MPAs), to promote poverty alleviation through food security and sustainable forms of development. From the time marine reserves were first shown to effectively address habitat degradation and decline in reef fishery production (Alcala et al., 2001) over 1,100 locally managed MPAs have been established in the Philippines; yet only 10-20% of these are effectively managed (White et al., 2006; PhilReefs, 2008). In order to increase management effectiveness, biophysical, legal, institutional and social linkages need to be strengthened and “scaled up” to accommodate a more holistic systems approach (Lowry et al., 2009). This summary paper incorporates the preliminary results of five independently conducted studies. Subject areas covered are the social and institutional elements of MPA networks, ecosystem-based management applicability, financial sustainability and the social vulnerability of coastal residents to climate change in the Central Philippines. Each section will provide insight into these focal areas and suggest how management strategies may be adapted to holistically address these contemporary issues. (PDF contains 4 pages)
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The South Carolina Coastal Information Network (SCCIN) emerged as a result of a number of coastal outreach institutions working in partnership to enhance coordination of the coastal community outreach efforts in South Carolina. This organized effort, led by the S.C. Sea Grant Consortium and its Extension Program, includes partners from federal and state agencies, regional government agencies, and private organizations seeking to coordinate and/or jointly deliver outreach programs that target coastal community constituents. The Network was officially formed in 2006 with the original intention of fostering intra-and inter- agency communication, coordination, and cooperation. Network partners include the S.C. Sea Grant Consortium, S.C. Department of Health and Environmental Control – Office of Ocean and Coastal Resource Management and Bureau of Water, S.C. Department of Natural Resources – ACE Basin National Estuarine Research Reserve, North Inlet-Winyah Bay National Estuarine Research Reserve, Clemson University Cooperative Extension Service and Carolina Clear, Berkeley-Charleston-Dorchester Council of Governments, Waccamaw Regional Council of Governments, Urban Land Institute of South Carolina, S.C. Department of Archives and History, the National Oceanic and Atmospheric Administration – Coastal Services Center and Hollings Marine Laboratory, Michaux Conservancy, Ashley-Cooper Stormwater Education Consortium, the Coastal Waccamaw Stormwater Education Consortium, the S.C. Chapter of the U.S. Green Building Council, and the Lowcountry Council of Governments. (PDF contains 3 pages)
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Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar.
Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry.
The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires.
Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction arrays. These devices offer potential efficiencies of 34%, as demonstrated through an analytical model and optoelectronic simulations. SiGe and Ge wires were fabricated via chemical-vapor deposition and reactive ion etching. GaAs was then grown on these substrates at the National Renewable Energy Lab and yielded ns lifetime components, as required for achieving high efficiency devices.
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The concept of a carbon nanotube microneedle array is explored in this thesis from multiple perspectives including microneedle fabrication, physical aspects of transdermal delivery, and in vivo transdermal drug delivery experiments. Starting with standard techniques in carbon nanotube (CNT) fabrication, including catalyst patterning and chemical vapor deposition, vertically-aligned carbon nanotubes are utilized as a scaffold to define the shape of the hollow microneedle. Passive, scalable techniques based on capillary action and unique photolithographic methods are utilized to produce a CNT-polymer composite microneedle. Specific examples of CNT-polyimide and CNT-epoxy microneedles are investigated. Further analysis of the transport properties of polymer resins reveals general requirements for applying arbitrary polymers to the fabrication process.
The bottom-up fabrication approach embodied by vertically-aligned carbon nanotubes allows for more direct construction of complex high-aspect ratio features than standard top-down fabrication approaches, making microneedles an ideal application for CNTs. However, current vertically-aligned CNT fabrication techniques only allow for the production of extruded geometries with a constant cross-sectional area, such as cylinders. To rectify this limitation, isotropic oxygen etching is introduced as a novel fabrication technique to create true 3D CNT geometry. Oxygen etching is utilized to create a conical geometry from a cylindrical CNT structure as well as create complex shape transformations in other CNT geometries.
CNT-polymer composite microneedles are anchored onto a common polymer base less than 50 µm thick, which allows for the microneedles to be incorporated into multiple drug delivery platforms, including modified hypodermic syringes and silicone skin patches. Cylindrical microneedles are fabricated with 100 µm outer diameter and height of 200-250 µm with a central cavity, or lumen, diameter of 30 µm to facilitate liquid drug flow. In vitro delivery experiments in swine skin demonstrate the ability of the microneedles to successfully penetrate the skin and deliver aqueous solutions.
An in vivo study was performed to assess the ability of the CNT-polymer microneedles to deliver drugs transdermally. CNT-polymer microneedles are attached to a hand actuated silicone skin patch that holds a liquid reservoir of drugs. Fentanyl, a potent analgesic, was administered to New Zealand White Rabbits through 3 routes of delivery: topical patch, CNT-polymer microneedles, and subcutaneous hypodermic injection. Results demonstrate that the CNT-polymer microneedles have a similar onset of action as the topical patch. CNT-polymer microneedles were also vetted as a painless delivery approach compared to hypodermic injection. Comparative analysis with contemporary microneedle designs demonstrates that the delivery achieved through CNT-polymer microneedles is akin to current hollow microneedle architectures. The inherent advantage of applying a bottom-up fabrication approach alongside similar delivery performance to contemporary microneedle designs demonstrates that the CNT-polymer composite microneedle is a viable architecture in the emerging field of painless transdermal delivery.
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This thesis presents a novel active mirror technology based on carbon fiber composites and replication manufacturing processes. Multiple additional layers are implemented into the structure in order to provide the reflective layer, actuation capabilities and electrode routing. The mirror is thin, lightweight, and has large actuation capabilities. These features, along with the associated manufacturing processes, represent a significant change in design compared to traditional optics. Structural redundancy in the form of added material or support structures is replaced by thin, unsupported lightweight substrates with large actuation capabilities.
Several studies motivated by the desire to improve as-manufactured figure quality are performed. Firstly, imperfections in thin CFRP laminates and their effect on post-cure shape errors are studied. Numerical models are developed and compared to experimental measurements on flat laminates. Techniques to mitigate figure errors for thicker laminates are also identified. A method of properly integrating the reflective facesheet onto the front surface of the CFRP substrate is also presented. Finally, the effect of bonding multiple initially flat active plates to the backside of a curved CFRP substrate is studied. Figure deformations along with local surface defects are predicted and characterized experimentally. By understanding the mechanics behind these processes, significant improvements to the overall figure quality have been made.
Studies related to the actuation response of the mirror are also performed. The active properties of two materials are characterized and compared. Optimal active layer thicknesses for thin surface-parallel schemes are determined. Finite element simulations are used to make predictions on shape correction capabilities, demonstrating high correctabiliity and stroke over low-order modes. The effect of actuator saturation is studied and shown to significantly degrade shape correction performance.
The initial figure as well as actuation capabilities of a fully-integrated active mirror prototype are characterized experimentally using a Projected Hartmann test. A description of the test apparatus is presented along with two verification measurements. The apparatus is shown to accurately capture both high-amplitude low spatial-frequency figure errors as well as those at lower amplitudes but higher spatial frequencies. A closed-loop figure correction is performed, reducing figure errors by 94%.
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The structure of the set ϐ(A) of all eigenvalues of all complex matrices (elementwise) equimodular with a given n x n non-negative matrix A is studied. The problem was suggested by O. Taussky and some aspects have been studied by R. S. Varga and B.W. Levinger.
If every matrix equimodular with A is non-singular, then A is called regular. A new proof of the P. Camion-A.J. Hoffman characterization of regular matrices is given.
The set ϐ(A) consists of m ≤ n closed annuli centered at the origin. Each gap, ɤ, in this set can be associated with a class of regular matrices with a (unique) permutation, π(ɤ). The association depends on both the combinatorial structure of A and the size of the aii. Let A be associated with the set of r permutations, π1, π2,…, πr, where each gap in ϐ(A) is associated with one of the πk. Then r ≤ n, even when the complement of ϐ(A) has n+1 components. Further, if π(ɤ) is the identity, the real boundary points of ɤ are eigenvalues of real matrices equimodular with A. In particular, if A is essentially diagonally dominant, every real boundary point of ϐ(A) is an eigenvalues of a real matrix equimodular with A.
Several conjectures based on these results are made which if verified would constitute an extension of the Perron-Frobenius Theorem, and an algebraic method is introduced which unites the study of regular matrices with that of ϐ(A).
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This investigation is concerned with various fundamental aspects of the linearized dynamical theory for mechanically homogeneous and isotropic elastic solids. First, the uniqueness and reciprocal theorems of dynamic elasticity are extended to unbounded domains with the aid of a generalized energy identity and a lemma on the prolonged quiescence of the far field, which are established for this purpose. Next, the basic singular solutions of elastodynamics are studied and used to generate systematically Love's integral identity for the displacement field, as well as an associated identity for the field of stress. These results, in conjunction with suitably defined Green's functions, are applied to the construction of integral representations for the solution of the first and second boundary-initial value problem. Finally, a uniqueness theorem for dynamic concentrated-load problems is obtained.
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Nesta dissertação, analisam-se alguns ditos populares retomados em músicas do cancioneiro popular, com base na teoria da metáfora conceptual (Lakoff e Jonhson, 1980; Kövecses, 2002), e na teoria da integração conceptual (Fauconnier e Turner, 2002). Busca se investigar se a projeção metafórica presente no dito empregado em situações cotidianas se sustenta, quando o mesmo é retomado em uma letra de música. Este estudo encontra sua justificativa em uma das assunções basilares da linguística cognitiva de que as metáforas conceptuais estão presentes tanto nas conversas cotidianas quanto nas manifestações literárias e artísticas. Pretende se, assim, observar a multidirecionalidade dos processos de significação desse tipo de construção linguística, a fim de postular seu poder projetivo e metafórico na mente dos falantes. Dentro do repertório de construções proverbiais em português, é perceptível a construção proverbial condicional com a configuração sintático semântica [x P Q], entre as quais foi escolhida como objeto de estudo a configuração [Quem P Q]. A escolha das músicas foi aleatória, já que não se buscou um gênero ou estilo específico, mas canções que possuíssem ditos populares em suas letras. Na análise, de cunho interpretativo, procedeu-se a identificação do papel da metáfora conceptual presente no dito empregado em situações cotidianas e nas 10 músicas selecionadas para este estudo. Em seguida, postularam-se redes de integração conceptual subjacente ao sentido dos ditos nas interações em geral e nas músicas, de modo a explicar que as diferenças de sentido observadas ou não nos ditos transpostos para letras de músicas estão relacionadas ao tipo de rede de integração conceptual ativado durante o processo de mesclagem. As redes de integração postuladas para explicar a construção de sentido dos ditos e destes nas músicas analisadas, revelam compressões das relações de CAUSA EFEITO, MUDANÇA, IDENTIDADE, ANALOGIA DESANALOGIA e TEMPO, devido, sobretudo, ao papel que os ditos desempenham ao ilustrar cenas da vida das pessoas. Entre as metáforas que estruturam os ditos, nas interações e nas músicas, encontram-se A VIDA É UMA VIAGEM / A VIDA É UM TRAJETO QUE DEVE SER PERCORRIDO COM CAUTELA / VIDA É UM JOGO DE AZAR; TEMPO É LOCAL PARA ONDE ALGO SE DESLOCA; DIFICULDADES SÃO IMPEDIMENTOS (IN) TRANSPONÍVEIS; RELIGIÃO É UMA TRANSAÇÃO COMERCIAL; MORAL É UM OBJETO PRECIOSO (MAS FRÁGIL COMO O VIDRO); EXAGEROS SÃO GOLPES INCERTOS. Espera-se que a hipótese aventada com este estudo motive outras pesquisas sob o escopo teórico da Linguística Cognitiva; em especial, as teorias da metáfora e da mesclagem conceptual, as quais revelaram um potencial descritivo promissor para análise de fenômenos semântico-pragmáticos da língua portuguesa, como os ditos populares, construções situadas no topo da escala de idiomaticidade
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Com vistas à conceptualização do conceito de BANDIDO em 32 expressões com a estrutura bandido de x, descrevemos, nesta dissertação, os modelos cognitivos idealizados subjacentes à construção de sentido de tais expressões, postulando-lhes um caráter de modelo cognitivo complexo, nos termos de Lakoff (1987), produtivo na língua. Constituem ainda o arcabouço teórico deste estudo a Teoria da Mesclagem Conceptual (FAUCONNIER e TURNER, 2002) e a Teoria da Metáfora Conceptual (LAKOFF e JOHNSON, 1980). A análise das construções bandido de x foi realizada a partir de 137 comentários retirados da internet e definições elaboradas por 15 alunos do ensino fundamental; 18 do ensino médio e 20 alunos do ensino superior. Os alunos que colaboraram com a pesquisa definiram 24 expressões bandido de x. A pesquisa obedeceu ao procedimento qualitativo de análise dos dados, no qual observamos as diferentes interpretações dadas para as expressões, fundamentando-as a partir dos processos cognitivos envolvidos no sentido das mesmas. Assim com base na análise dos comentários de internautas e nas definições de alunos, propomos quatro processos de conceptualização para as expressões bandido de x: (a) conceptualização com base em modelos cognitivos proposicionais, em que x é um locativo interpretado como lugar de origem ou de atuação do bandido bandido de morro, bandido de rua, bandido de cadeia ; (b) conceptualização com base em modelos esquemático-imagéticos, em que observamos a atribuição de uma espécie de escala ao sentido atribuído à construção, culminando em diferentes status para a categoria BANDIDO DE X, subjacente a expressões bandido de primeira/segunda/quinta categoria/linha; (c) conceptualização de BANDIDO DE X com base em modelos metonímicos, em que x é uma peça do vestuário/calçado/acessório, de modo a interpretar o BANDIDO como pertencendo a uma categoria que costuma utilizar determinada peça de roupa, acessório ou calçado bandido de colarinho branco, bandidos de farda, bandido de chinelo ; (d) conceptualização de BANDIDO DE X com base em modelos metafóricos, em que x é um conceito abstrato que pode ser entendido como um objeto possuído pelo bandido, de forma a caracterizá-lo pela maneira de agir ou expertise bandido de conceito, bandido de atitude, bandido de fé. Acreditamos, assim, na possibilidade de descrição de padrões que regem a conceptualização de BANDIDO DE X, cujos sentidos alcançados por meio de modificadores revelam a produtividade e complexidade do modelo cognitivo BANDIDO