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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

Variação espaço-temporal da macrofauna bêntica da Plataforma Continental Oeste da Península Antártica / Spatiotemporal variation of benthic macrofauna on the West Antarctic Peninsula shelf

Karin Lutke Elbers 29 January 2010 (has links)
A Plataforma Oeste da Península Antártica (POPA) é uma região onde a produtividade primária na superfície do oceano apresenta padrões altamente sazonais e considerável variabilidade interanual. A dinâmica do gelo marinho é o principal fator condicionante da produtividade e, por consequência, dos fluxos de matéria orgânica da superfície para o leito marinho. A matéria orgânica particulada depositada, chamada de fitodetrito, forma densas camadas de alimento lábil disponível para os organismos bênticos. Essa relação estreita entre os processos da coluna de água e aqueles que ocorrem no bentos é chamada de acoplamento bento-pelágico. Com o objetivo de avaliar as respostas da macrofauna bêntica aos fluxos e deposição de alimento, foi realizada uma série temporal sazonal de amostragens (novembro/1999 a março/2001) na POPA em três estações de coleta perpendiculares à costa. Cerca de 25.000 indivíduos pertencentes a 22 táxons foram coletados em 15 amostras de box corer (0,25 m2 cada). Mesmo com alguma variação ao largo da plataforma (de 10.886 ind.m-2 (estação A) a 2.326 ind.m-2 (B)), atribuída a diferenças na topografia, a macrofauna apresentou pouca variabilidade em termos de composição e abundância ao longo do período estudado. Além disso, diferenças na composição e abundância entre estratos sedimentares também foram notáveis, sendo que 90% dos indivíduos foram encontrados entre 0 e 5 cm. Dentre as 185 espécies identificadas, Aurospio foodbancsia (Polychaeta, Spionidae), uma espécie típica de regiões de plataforma na Antártica, mas muito próxima da espécie de mar profundo A. dibranchiata, foi a espécie dominante em todos os períodos e estações (2.087 ind.m-2). Além de Polychaeta, outros grupos abundantes na POPA foram Bivalvia, Tanaidacea e Oligochaeta. Picos de abundância foram observados para algumas espécies, provavelmente associados a eventos sazonais de recrutamento, porém nem sempre associados à chegada do alimento ao fundo marinho da região. Os grupo funcionais de Polychaeta também não variaram ao longo do período estudado, o que indicou que animais depositívoros de superfície e subsuperfície se alimentam ao longo de todo o ano, aproveitando o alimento que permanece lábil e disponível, mesmo no inverno, quando o fluxo de matéria orgânica para o bentos é mínimo. Os resultados encontrados neste trabalho confirmam os resultados já encontrados dentro do projeto FOODBANCS, que a macrofauna da POPA age como um filtro, respondendo menos às flutuações sazonais. / The West Antarctic Peninsula shelf (WAP shelf) experiences a high seasonal and interannual variability in surface primary production. Sea ice dynamics is the principal factor controlling productivity and, therefore, the downward particulate organic matter (POM) fluxes. The deposited POM, also called phytodetritus, forms dense layers of available labile food for benthic organisms. This straight relationship between water column and benthic processes is called benthic-pelagic coupling. A seasonal time-series study was conducted between November 1999 through March 2001 in tree sites on WAP shelf, to determine this relationship, specially the benthic macrofauna (> 300 µm) response to the POM flux and its posterior deposition. From a total of 15 box-corer samples (0.25 m2 each), approximately 25,000 macrofaunal individuals were collected, belonging to 22 taxa. Even with some variation along the shelf, ranging from 10,886 ind.m-2 (site A) to 2,326 ind.m-2 (B), the abundance and composition of macrofauna showed only modest seasonal changes. Differences in these parameters were clear between the inner and outer shelves, probably owing to the topography, which was composed of a basin in the innermost region and a flat region, in the offshore area. Differences in abundance and composition between sediment layers were also notable, with 90% of all individuals belonging to the 0-5 cm layer. Among the 185 identified species, Aurospio foodbancsia (Polychaeta, Spionidae), a typical species of Antarctic shelf regions and closely related to the deep-sea species A. dibranchiata, was dominant in all seasons and sites (2,087 ind.m-2). Besides polychaetes, bivalves, tanaids and oligochaetes were also abundant in WAP shelf. Peaks in abundance were observed for some species and this is believed to be related to seasonal recruitment, however not always associated with the availability of food. Polychaete functional groups did not vary along seasons, indicating that surface and subsurface deposit feeders were subsisting on the labile POM along the year, even during the winter, when POM flux to the benthos is extremely low. The results are similar to those obtained in other FOODBANCS works, and indicate that the WAP shelf macrofauna act as a low-pass filter, muting the seasonal water column processes.
532

Qualidade do tambaqui (Colossoma macropomum) armazenado em gelo: métodos sensoriais, físico-químicos e microbiológicos / Quality of tambaqui (Colossoma macropomum) stored on ice: sensory, physico-chemical and microbiological methods

Silva, Márcio Luís Pontes Bernardo de 26 March 2014 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-22T18:57:22Z No. of bitstreams: 1 MarcioSilva.pdf: 1636302 bytes, checksum: 2d6a8473ae527d2c774587fbf3fd6f4c (MD5) / Made available in DSpace on 2017-06-22T18:57:22Z (GMT). No. of bitstreams: 1 MarcioSilva.pdf: 1636302 bytes, checksum: 2d6a8473ae527d2c774587fbf3fd6f4c (MD5) Previous issue date: 2014-03-26 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / This study aimed to develop a scheme based on the Quality Index Method (QIM) to tambaqui (Colossoma macropomum) raw stored in ice that determines its shelf life. It was studied 96 specimens of tambaqui captured with fishing net and slaughtered (killed) by hypothermia in ice and water , it was packed in ice boxes and kept on ice in a 1:1 (Kg fish/ice) ratio at a controlled temperature of 0 ± 1 ° C for 24 days. Fishes were evaluated at time 01 , 03 , 05 , 08 , 10 , 12 , 15 , 17 , 19 , 22 , 24 day of ice storage. After sensory, physical-chemistry and microbiological analyses the developed scheme presented 04 quality attributes with a total of 30 points. The pH showed little variation from 6.52 to 6.71, from the beginning to end of the experiment. The average content of BVT changed from 15.23 mg N.100g- 1 to 23.17 mg N.100g- 1 and it did not reach the amount considered unsafe for consumption. Mesophilic, and Psicotrophic bacteria remained with their values below log 106. The experiments with Pseudomonas and Enterobacterias showed their values below the limit recommended by the World Health Organization (WHO) that is log 107, and it was demonstrated by producer bacteria H2S a growth of values reduced throughout the experiment. Then the method proved to be efficient to assess the loss of sensory quality related to the length of time in storage and it indicated an expiration date of 22 days which determine the shelf life of tambaqui. Microbiological analyzes with specific bacterial counts of deteriorating organisms strengthen the sensory results and it suggests the tambaqui (Colossoma macropomum) raw stored in ice is fit for consumption until the 22nd day. / Este estudo teve como objetivo desenvolver um protocolo baseado no Método de Índice de Qualidade (MIQ) para o tambaqui (Colossoma macropomum) inteiro armazenado em gelo e determinar sua vida de prateleira. Foram utilizados 96 exemplares capturados com rede de despesca e abatidos por hipotermia em água com gelo, acondicionados em caixas isotérmicas mantidas em gelo na proporção de 1:1(Kg peixe/gelo), a uma temperatura controlada de 0±1 °C durante 24 dias. Os peixes foram avaliados nos tempos 01, 03, 05, 08, 10, 12, 15, 17, 19, 22, 24 dias de armazenamento em gelo. Realizadas análises sensoriais, físico-químicas e microbiológicas. O protocolo desenvolvido apresentou 04 atributos de qualidade, cuja soma totalizou 30 pontos. O pH mostrou pequena variação média de 6,52 a 6,71, do início ao final do experimento. O teor médio de BVT variou de 15,23 mg N.100g-1 a 23,17 mg N.100g-1 não atingindo o valor considerado impróprio para o consumo. As bactérias Mesófilas, Psicrófilas e Psicotróficas mantiveram-se com seus valores médios abaixo de log 106. As bactérias Pseudomonas e Enterobactérias apresentaram seus valores médios entre os experimentos próximos abaixo do limite máximo preconizado pela Organização Mundial da Saúde (OMS) que é log 107 e valores reduzidos de crescimento foram demonstrados por bactérias produtoras de H2S durante todo o experimento. Para determinação da vida de prateleira o método mostrou-se eficiente para avaliar a perda de qualidade sensorial relacionada com o tempo de armazenamento, indicando um prazo de validade de 22 dias. As análises microbiológicas, com a contagem bacteriana de organismos deterioradores específicos, reforçam os resultados sensoriais, sugerindo que o tempo de vida de prateleira para o tambaqui inteiro armazenado em gelo é de 22 dias.
533

Efeito do tratamento térmico e do ácido salicílico na atividade de polifenoloxidase, peroxidase e fenilalanina amônia-liase, nas características físico-químicas e na incidência de patógenos em morangos durante o armazenamento / Effect of heat treatment and salicylic acid on polyphenoloxidase, peroxidase and phenylalanine ammonia-liase activity, physical-chemistry characteristics and incidence of pathogens in strawberries during storage

Coltro, Sidiane 27 February 2012 (has links)
Made available in DSpace on 2017-07-10T17:37:51Z (GMT). No. of bitstreams: 1 Sidiane_Coltro.pdf: 604676 bytes, checksum: eccb769c94921f8082441892d38b80d7 (MD5) Previous issue date: 2012-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The strawberry is a fruit that is highly perishable and are very susceptible to physical damage and fungal attack. The use of fungicides has been the primary method for reducing post-harvest diseases. Accordingly, alternative methods free of chemicals must be used in post-harvest to maintain the quality and prolong the life reduce the incidence of fungi. Therefore, this study aimed to evaluate the effect of heat treatment and post-harvest salicylic acid in the response of strawberry-related activities of the enzymes polyphenol oxidase and peroxidase, the contents of total phenols, anthocyanins and ascorbic acid and the incidence of pathogens during storage of fruits. This study was divided into two experiments. In the first experiment, Dover strawberries were treated thermally in an oven at 45°C for 3 hours and stored at 5°C for 1, 7 and 14 days and analyzed. After these periods, the fruit were removed and transferred to the cooling environment at 20°C for 2 days to be analyzed again. We used a completely randomized in factorial scheme (2x6), with 12 treatments and four replicates of 10 berries per tray. In the second experiment, strawberries Dover were heat treated in an oven with forced air at 45°C for 3 hours and after immersed in a solution of salicylic acid 2.0 mM L-1 for 5 minutes; then they were stored under refrigeration (5°C) and after 1,7 and 14 days and transferred to a room at 20°C for 2 days and the be analyzed. The design was completely randomized in factorial scheme (4x3), with 12 treatments and four replications. Were evaluated the activity of polyphenoloxidase, peroxidase, phenylalanine ammonia-lyase, the incidence of fungi, total phenols, anthocyanins, ascorbic acid, pH, titratable acidity, soluble solid and weight loss. It was found that the metabolism postharvest Dover cv. strawberry has been modified by application of heat treatment, because the results showed that the activity of polyphenoloxidase, peroxidase and phenylalanine ammonia-lyase and ascorbic acid, total phenols and anthocyanins, and the incidence of fungi were lower in heat-treated strawberries. The heat treatment resulted in higher acidity, higher soluble solids and lower mass loss. The heat treatment is not provided, according to the incidence of fungi and weight loss, increased shelf life of strawberries, being limited to seven days of storage. However, the addition of salicylic acid to heat treatment was less effective than other treatments for most variables, indicating that it is disadvantageous. However, heat shock alone was more effective in reducing the activity of peroxidase, polyphenoloxidase showed lower activity compared to the control at 7 +2 days and did not differ from other treatments at 14 +2 days, was effective in maintaining high levels phenolic compounds, anthocyanins and ascorbic acid up to 7 +2 days / O morango é um fruto que apresenta alta perecibilidade e, são bastante suscetíveis a danos físicos e ataque de fungos. O uso de fungicidas químicos tem sido o principal método para reduzir as doenças pós-colheita. Nesse sentido, métodos alternativos livres de produtos químicos devem ser utilizados em pós-colheita para manter a qualidade, prolongar a vida útil e diminuir a incidência de fungos. Assim, o presente trabalho teve por objetivo avaliar o efeito do tratamento térmico pós-colheita e do ácido salicílico na resposta do morango relacionada à atividade das enzimas polifenoloxidase e peroxidase, aos conteúdos de fenóis totais, antocianinas e ácido ascórbico e à incidência de patógenos durante o armazenamento dos frutos. Este estudo foi dividido em dois experimentos. No primeiro experimento, morangos cultivar Dover, foram tratados termicamente em estufa a 45°C por 3 horas e armazenados a 5 ºC por 1, 7 e 14 dias e analisados. Após esses períodos, os frutos foram retirados da refrigeração e transferidos para ambiente a 20 ºC por 2 dias para serem analisados novamente. Foi utilizado o delineamento inteiramente casualizado, em esquema fatorial (2x6), com 12 tratamentos e quatro repetições com 10 morangos por bandeja. No segundo experimento, morangos cultivar Dover foram tratados termicamente em estufa com circulação forçada de ar com 45°C por 3 horas e depois imergidos em solução de ácido salicílico 2,0 mMol L-1 por 5 minutos, depois foram armazenados sob refrigeração (5°C) e após 1, 7 e 14 dias foram transferidos para ambiente a 20 ºC por 2 dias para então serem analisados. O delineamento foi inteiramente casualizado, em esquema fatorial (4x3), com 12 tratamentos e quatro repetições. Foram avaliados a atividade de polifenoloxidase, peroxidase, fenilalanina amônia-liase, incidência de fungos, fenóis totais, antocianinas, ácido ascórbico, pH, acidez titulável, sólidos solúveis e perda de massa. Foi constatado que, o metabolismo pós-colheita de morangos cv. Dover foi modificado pela aplicação de tratamento térmico, pois os resultados mostraram que a atividade de polifenoloxidase, peroxidase e fenilalanina amônia-liase e os teores de ácido ascórbico, fenóis totais e antocianinas e a incidência de fungos foram inferiores em morangos tratados termicamente. O tratamento térmico resultou em maior acidez titulável, maior teor de sólidos solúveis e menor perda de massa. O tratamento térmico não proporcionou, segundo a incidência de fungos e a perda de massa, aumento da vida útil dos morangos, ficando limitado aos sete dias de armazenamento refrigerado. Entretanto, a adição de ácido salicílico ao tratamento térmico, se mostrou menos efetivo que os demais tratamentos para a maioria das variáveis analisadas, indicando ser desvantajoso. Porém, o choque térmico isolado mostrou-se mais efetivo em reduzir a atividade de peroxidase, apresentou atividade inferior de polifenoloxidase comparado ao controle aos 7+2 dias e não diferiu dos demais tratamentos aos 14+2 dias, se mostrou efetivo em manter níveis elevados de compostos fenólicos, antocianinas e ácido ascórbico até 7+2 dias
534

Resposta da Plataforma Continental Sudeste a ventos sazonais e sinóticos de verão: estudos numéricos / Response of the South Brazil bight to summer seasonal and synoptic winds: numerical studie

Alexandre Luiz Coelho 29 February 2008 (has links)
Com a finalidade de estudar as perturbações médias sobre a Plataforma Continental Sudeste (PCSE) causadas pela passagem de uma frente fria durante o verão, obteve-se um estado básico médio de correntes. Esse campo médio foi obtido com o POM (Princeton Ocean Model) através de simulação diagnóstica, seguida por curta rodada prognostica. As correntes modeladas para o verão na Plataforma Continental Sudeste assemelharam-se em alguns aspectos a correntes obtidas em fundeios de correntógrafos realizados pela Diretoria de Hidrografia e Navegação (DHN), e pelo Instituto Oceanográfico da Universidade de São Paulo, durante os projetos Ciculação Oceânica na Região Oeste do Atlântico Sul (COROAS) e Dinâmica do Ecossistema de Plataforma da Região Oeste do Atlântico Sul (DEPROAS), validando os resultados do modelo Durante a passagem da frente fria as correntes invertem em cerca de seis a nove horas após a passagem do sistema frontal por cada região da PCSE. As etapas da subsidência costeira foram modeladas, ocorrendo transporte de deriva do vento em direção à costa, na camada superficial (0-10m), e transporte de compensação ao longo da coluna d\'água, havendo empilhamento de água na região costeira. A força de gradiente de pressão barotrópica desenvolvida implicou na formação e intensificação do jato costeiro em direção a menores latitudes. Durante esse estado transiente associado à passagem do sistema frontal, a Água Tropical aproxima-se da costa em nível sub-superficial, misturando-se com as águas da plataforma continental A porção da Plataforma Continental Sudeste localizada ao sul da Ilha de São Sebastião é a que responde com maior intensidade à passagem do sistema meteorológico frontal. Na direção transversal à costa, predomina o balanço geostrófico, o qual é intensificado durante a passagem da frente fria, enquanto que ao longo da costa as águas são desviadas do referido balanço pela tensão de cisalhamento do vento e pela aceleração local. Em Cananéia, ocorre a maior amplitude de variação do nível do mar, que pode estar associada a um mecanismo de ressonância entre os ventos do sistema frontal e Ondas de Plataforma Continental geradas pelo vento, uma vez que possuem velocidades de propagação próximas. A plataforma continental adquire vorticidade relativa ciclônica durante a passagem da frente fria. / In order to study the pertubations caused on the South Brazil Bigth (SBB) caused by the passage of a cold front during Summer, a mean basic state for currents was obtained using the POM (Princeton Ocean Model) through diagnostic simulation, followed by a short round prognostic. The mean currents modeled are in certain instancies similar to the currents measured by meter moorings deployed by the Directorate of Hydrography and Navigation (DHN), and by Oceanographic Institute of the University São Paulo during the Projects Oceanic Circulation in the Western South Atlantic (COROAS) and Dynamic of the Ecosystem of the Shelf of the Western South Atlantic Region (DEPROAS), validating results model. During the cold front passage, the currents invert six to nine hours after the passage of the frontal system through each region of the SBB. The stages of coastal subsidence were modeled, with coastward wind drift transport at superficial layer and offshore compensation transport throughout the water column, with piling of water in the coastal region. The strength of the barotropic pressure gradient developed caused the formation and intensification of a coastal jet. During this transient stage associated with the passage of the frontal system, the Tropical Water approaches the coast within sub-surface layer, mixing with continental shelf waters. The portion of SBB located to the South of São Sebastião Island is the portion which is most influenced by the passage of the frontal system. In a normal direction to the coast, the geostrophic balance predominates, being intensified during the passage of the cold front, while along the coast, the waters is diverted from this balance by the wind stress and by the local acceleration, which tend to have opposite signs. Near Cananéia, there is the highest sea level elevation, which may be associated with a mechanism of resonance between the winds of the frontal system and the Continental Shelf Waves generated by the wind, since they have the same speed of propagation. The continental shelf acquires cyclonic relative vorticity during the passage of the cold front.
535

The contributions of UNCLOS dispute settlement bodies to the development of the law of the sea

Nguyen, Lan Ngoc January 2019 (has links)
This thesis seeks to systematically examine the contributions made by the dispute settlement bodies established under the United Nations Convention on the Law of the Sea (UNCLOS) to the development of the law of the sea. The two main research questions to be answered are: (i) what kind of contribution have UNCLOS dispute settlement bodies made to the development of the law of the sea? and (ii) what are the factors that impact the performance of UNCLOS dispute settlement bodies in developing the law of the sea? To that end, Chapter 1 provides a working definition for the concept of 'judicial development of international law' in order to establish a framework for an assessment of the contributions of UNCLOS tribunals. Based on this working definition, Chapters 2, 3 and 4 examine the significance of UNCLOS tribunals' decisions in the development of three main areas of the law of the sea, respectively the law on fisheries, the law on the outer continental shelf and the law on marine environmental protection. Based on the findings of these chapters, Chapter 5 analyses the factors that help explain the contributions of UNCLOS tribunals to the law of the sea as identified in the preceding chapters. These factors include: (i) the jurisdictional scope of UNCLOS tribunals, (ii) the institutional design of UNCLOS, (iii) the interpretative method employed by UNCLOS tribunals in deciding their cases and (iv) the perception that UNCLOS tribunals hold regarding their roles. Chapter 6 concludes by taking stock of the contribution of UNCLOS tribunal in these areas and offering some final observations on the role of UNCLOS tribunals in the development of the law of the sea.
536

Variação espaço-temporal da macrofauna bêntica da Plataforma Continental Oeste da Península Antártica / Spatiotemporal variation of benthic macrofauna on the West Antarctic Peninsula shelf

Elbers, Karin Lutke 29 January 2010 (has links)
A Plataforma Oeste da Península Antártica (POPA) é uma região onde a produtividade primária na superfície do oceano apresenta padrões altamente sazonais e considerável variabilidade interanual. A dinâmica do gelo marinho é o principal fator condicionante da produtividade e, por consequência, dos fluxos de matéria orgânica da superfície para o leito marinho. A matéria orgânica particulada depositada, chamada de fitodetrito, forma densas camadas de alimento lábil disponível para os organismos bênticos. Essa relação estreita entre os processos da coluna de água e aqueles que ocorrem no bentos é chamada de acoplamento bento-pelágico. Com o objetivo de avaliar as respostas da macrofauna bêntica aos fluxos e deposição de alimento, foi realizada uma série temporal sazonal de amostragens (novembro/1999 a março/2001) na POPA em três estações de coleta perpendiculares à costa. Cerca de 25.000 indivíduos pertencentes a 22 táxons foram coletados em 15 amostras de box corer (0,25 m2 cada). Mesmo com alguma variação ao largo da plataforma (de 10.886 ind.m-2 (estação A) a 2.326 ind.m-2 (B)), atribuída a diferenças na topografia, a macrofauna apresentou pouca variabilidade em termos de composição e abundância ao longo do período estudado. Além disso, diferenças na composição e abundância entre estratos sedimentares também foram notáveis, sendo que 90% dos indivíduos foram encontrados entre 0 e 5 cm. Dentre as 185 espécies identificadas, Aurospio foodbancsia (Polychaeta, Spionidae), uma espécie típica de regiões de plataforma na Antártica, mas muito próxima da espécie de mar profundo A. dibranchiata, foi a espécie dominante em todos os períodos e estações (2.087 ind.m-2). Além de Polychaeta, outros grupos abundantes na POPA foram Bivalvia, Tanaidacea e Oligochaeta. Picos de abundância foram observados para algumas espécies, provavelmente associados a eventos sazonais de recrutamento, porém nem sempre associados à chegada do alimento ao fundo marinho da região. Os grupo funcionais de Polychaeta também não variaram ao longo do período estudado, o que indicou que animais depositívoros de superfície e subsuperfície se alimentam ao longo de todo o ano, aproveitando o alimento que permanece lábil e disponível, mesmo no inverno, quando o fluxo de matéria orgânica para o bentos é mínimo. Os resultados encontrados neste trabalho confirmam os resultados já encontrados dentro do projeto FOODBANCS, que a macrofauna da POPA age como um filtro, respondendo menos às flutuações sazonais. / The West Antarctic Peninsula shelf (WAP shelf) experiences a high seasonal and interannual variability in surface primary production. Sea ice dynamics is the principal factor controlling productivity and, therefore, the downward particulate organic matter (POM) fluxes. The deposited POM, also called phytodetritus, forms dense layers of available labile food for benthic organisms. This straight relationship between water column and benthic processes is called benthic-pelagic coupling. A seasonal time-series study was conducted between November 1999 through March 2001 in tree sites on WAP shelf, to determine this relationship, specially the benthic macrofauna (> 300 µm) response to the POM flux and its posterior deposition. From a total of 15 box-corer samples (0.25 m2 each), approximately 25,000 macrofaunal individuals were collected, belonging to 22 taxa. Even with some variation along the shelf, ranging from 10,886 ind.m-2 (site A) to 2,326 ind.m-2 (B), the abundance and composition of macrofauna showed only modest seasonal changes. Differences in these parameters were clear between the inner and outer shelves, probably owing to the topography, which was composed of a basin in the innermost region and a flat region, in the offshore area. Differences in abundance and composition between sediment layers were also notable, with 90% of all individuals belonging to the 0-5 cm layer. Among the 185 identified species, Aurospio foodbancsia (Polychaeta, Spionidae), a typical species of Antarctic shelf regions and closely related to the deep-sea species A. dibranchiata, was dominant in all seasons and sites (2,087 ind.m-2). Besides polychaetes, bivalves, tanaids and oligochaetes were also abundant in WAP shelf. Peaks in abundance were observed for some species and this is believed to be related to seasonal recruitment, however not always associated with the availability of food. Polychaete functional groups did not vary along seasons, indicating that surface and subsurface deposit feeders were subsisting on the labile POM along the year, even during the winter, when POM flux to the benthos is extremely low. The results are similar to those obtained in other FOODBANCS works, and indicate that the WAP shelf macrofauna act as a low-pass filter, muting the seasonal water column processes.
537

The Effects of Sediment Properties on Barrier Island Morphology and Processes: A Numerical Modeling Experiment

Kime, Brittany 20 December 2018 (has links)
Barrier island restoration and nourishment is necessary for sustaining coastal systems worldwide. In the Mississippi River Delta Plain, the lack of sediment supply, relative sea level rise, and reworking of abandoned delta lobes promote rapid disintegration of barriers, which can contribute to mainland storm impacts. Barrier island restorations that utilize higher quality sediments (Outer Continental Shelf- OCS) are expected to exhibit higher resiliency, withstanding coastal erosion, event-induced erosion, and ongoing transgression when compared to barriers nourished using lower quality nearshore (NS) sands. Additionally, use of OCS sediments increases sediment supply by adding material to the system supporting increased barrier longevity by maintaining a subaerial footprint longer compared to NS sediments. We used the Delft3D modeling suite to study barrier geomorphic trajectories nourished using OCS/NS sands, compared with control simulations with no nourishment. Resulting morphologies from 18 simulations with forcing that included annualized forcing, storms, and SLR are evaluated and compared.
538

Origin of surface undulations at the Kamb Ice Stream grounding line, West Antarctica

Seifert, Fiona Bronwyn 01 January 2012 (has links)
The West Antarctic Ice Sheet is drained primarily by five major ice streams, which together control the volume of ice discharged into the ocean across the grounding line. The grounding line of Kamb Ice Stream (KIS) is unusual because the ice stream upstream of it is stagnant. Here, a set of surface features--shore-parallel, long wavelength, low amplitude undulations--found only at that grounding line are examined and found to be "pinch and swell" features formed by an instability in the viscous deformation of the ice. When a relatively competent layer is surrounded by lower strength materials, particular wavelength features within the layer may be amplified under certain layer thickness and strain rate conditions. The undulations at KIS grounding line are possible due to the relatively large strain rates and particular ice thickness at that location. Several data sets are used to characterize the surface features. High resolution surface profiles are created using kinematic GPS carried on board a sled that was used to tow ice penetrating radar equipment. The radar data are used to examine the relationship between surface shape and basal crevasses. Additional surface profiles are created using ICESat laser altimeter observations. Repeat GPS surveys of a strain grid across the grounding line yields strain rate information. Analysis of repeat observations over tidal cycles and multi-day intervals shows that the features are not standing or traveling waves. Together, these observations are then used to evaluate the contributions of elastic and viscous deformation of the ice in creating the grounding line undulations.
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Effects of Potassium Lactate, Encapsulated Citric Acid and Storage Temperature on Microbial Growth and Shelf Life of Pork Sticks

Su, Yen-Kan 01 May 1992 (has links)
A new product, pork sticks, was developed. Optimum shelf life and safety were major concerns associated with this product. Potassium lactate (3%) or citric acid (0.5%, 0.56%, 0.60% or 0.66%) was added to pork sticks to determine their effects on microbial growth, sensory evaluation, and shelf life when stored frozen (-20°C), refrigerated (2°C), or at room temperature (22°C). Two raw materials, pork blade meat (shoulder meat; 91% lean, 9% fat) and regular 80:20 pork trim (80% lean, 20% fat) were used. The consumer panel preferred lean pork sticks made from blade meat over high-fat pork sticks made from regular 80:20 pork trim, regardless of the addition of potassium lactate (3%) or citric acid (0.5%). Pork sticks vacuum-packaged and held at 2°C or -20°C did not develop bacterial spoilage during six months storage. However, bacterial spoilage and oxidative rancidity occurred in the unpackaged control samples held at 22°C for one month. Incorporation of potassium lactate (3%) or citric acid (0.5%) decreased the color uniformity and red color intensity and increased the brown color intensity of the pork sticks made from blade meat. Vacuum-packaged pork sticks with added citric acid (0.56%, 0.60% and 0.66%) stored at 22°C did not develop bacterial spoilage, but discoloration occurred after one month storage.
540

Evolution morphologique et processus sédimentaires actuels du plateau continental interne sud-aquitain : étude comparée des zones de la Salie-Biscarosse (Sud des passes d'Arcachon) et la zone de la tête du canyon de Capbreton. / Morphological evolution and current sedimentary processes of the south Aquitain inner- shelf

Mazières, Alaïs 23 October 2014 (has links)
Ce travail présente une analyse de l'évolution morphologique et des processus sédimentaires actuels du plateau continental interne sud-aquitain, (sud-est du Golfe de Gascogne, France),secteur riche en données, mais sur lequel de nombreuses questions restent néanmoins en suspens. Il s'articule autour de deux zones ateliers complémentaires : la zone de « La Salie-Biscarrosse » sur le plateau continental interne sud-aquitain au sud des passes du Bassin d'Arcachon (entre 5 et 50 m de profondeur d’eau), et la tête du canyon de Capbreton et ses abords (entre 5 et 120 m de profondeur d’eau). Deux approches sont utilisées : (1) une approche descriptive et comparative (dans le temps), utilisant des données géo-acoustiques(sondeur multi faisceaux, sonar latéral et sondeur de sédiments), des prélèvements et (2) une approche mettant en oeuvre des modélisations numériques des interactions houles / courants /sédiments. Les résultats obtenus sur le plateau interne aquitain ont permis d'améliorer la connaissance de la morphologie, de la nature et de la géométrie interne des corps sédimentaires, d'étudier leur évolution au cours des 29 dernières années (entre 1984 et 2013)et de proposer des facteurs à l’origine de cette évolution. Le résultat majeur est la mise en évidence de « sorted bebforms » entretenus par la houle; dont la surprenante migration vers le nord-est est à associer à la récente découverte d'intenses épisodes de « poleward current » sur le plateau. Le suivi entre 1998 et 2013 de l’évolution morphologique de la tête du Canyon de Capbreton, située à seulement 250 m du littoral montre une évolution rapide qui fluctue cependant autour d'une position d'équilibre. Par ailleurs l’influence de la dérive littorale sur les transferts de sédiments du plateau vers le canyon a pu être démontrée. En-effet, les arguments morphologiques et sédimentaires, associés à la modélisation numérique, prouvent que la dérive littorale aquitaine alimente épisodiquement (conditions de houle forte) la tête de canyon en sables littoraux. / This study proposes an analysis of the morphological evolution and recent sedimentary processes of the south Aquitaine inner shelf (south east Bay of Biscay, France). This area is greatly documented but improvement of our knowledge is needed for a better understanding.Two complementary study areas are analyzed: « La Salie-Biscarrosse » area of the south-Aquitaine inner shelf (in a water depth extending from 5 to 50 m), and the head of the Capbreton Canyon (in a water depth extending from 5 to 120 m). Two approaches are used:(1) a descriptive and comparative analysis of the geophysical and sedimentological data setsand (2) a numerical modeling taking into account swell, current and sediments. The results obtained allow the description and the interpretation of the morphology, the nature, the internal geometry of the sedimentary structures, and their evolution along the last 29 years(between 1984 and 2013). The major result highlights the presence of sorted bedforms maintained by the swell, migrating northeastward and associated with the recent discovery of punctual poleward current on the shelf. The seafloor morphology of the Capbreton Canyonhead located only 250 m off the coastline, has experienced significant changes between 1998 and 2013, nonetheless it oscillates around a position of equilibrium. Furthermore, the influence of the littoral drift on sediment transfer from the shelf to the canyon was demonstrated. Sedimentary and morphological evidences combined with numerical modelingattest to the feeding of the Capbreton canyon head with coastal sand supplied by the southward long shore drift under high-energy wave conditions.

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