Gotowe bibliografie tematyczne / Sediments

Gotowa bibliografia na temat „Sediments”

Autor: Grafiati
Data publikacji: 4 czerwca 2021
Data aktualizacji: 28 lipca 2024

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Artykuły w czasopismach na temat "Sediments"

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Ooi, Jieun Lin, Lee Woen Ean, Bashar S. Mohammed, M. A. Malek, Leong Sing Wong, Chao Wei Tang i He Qing Chua. "Study on the Properties of Compressed Bricks Using Cameron Highlands Reservoir Sediment as Primary Material". Applied Mechanics and Materials 710 (styczeń 2015): 25–29. http://dx.doi.org/10.4028/www.scientific.net/amm.710.25.

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This research is to investigate the properties of compressed building bricks producedfrom Cameron Highlands reservoir sediment. The particle size distribution of the sediments are graded as silt and sand. The sediments used were as total replacement of the normal soils used in the compressed soil bricks. This paper presents the compilation of experimental brick properties; compressive strength, water absorption, microstructure and heavy metal leachingof the compressed sediment bricks. The experimental results shows that increasing use of reservoir sediments decrease the compressive strength andincrease the water absorption. The heavy metal concentrations of the leachates from the leaching test are all within the regulatory limits. The optimum mix is derives from the compressive strength and the water absorption in which in this research is Mix 4, 70% sedimenta, 20% sedimentb and 10% cement,complying with ASTM C129 – Non Load Bearing Bricks [1].
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Rosa, Kátia Kellem da, Rosemary Vieira i Jefferson Cardia Simões. "Identificação de Mudanças Ambientais Através da Caracterização Sedimentar e Investigação de Processos Glaciogênicos e Paraglaciais no Ambiente Glacial da Geleira Wanda, Ilha Rei George, Antártica (Identification of Environmental Change Through...)". Revista Brasileira de Geografia Física 6, nr 1 (17.07.2013): 029. http://dx.doi.org/10.26848/rbgf.v6i1.232807.

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Este estudo objetiva identificar as características sedimentares associadas aos depósitos glaciogênicos e sedimentos com modificação por processos não glaciais na área proglacial da geleira Wanda, Ilha Rei George, Antártica. A metodologia foi desenvolvida através de atividades de campo realizadas durante a estação de verão em 2007, 2010 e 2011. Os sedimentos foram analisados para determinar a distribuição granulométrica e características morfoscópicas. Este estudo apresenta resultados de interpretações dos sedimentos coletados na proglacial da geleira Wanda. A análise sedimentar possibilita a distinção de sedimentos glaciogênicos e dos sedimentos modificados por atividade paraglacial, podendo evidenciar mudanças ambientais em decorrência do aumento da temperatura atmosférica superficial e da precipitação líquida. AbstractThis study arms identify sediment characteristics related to glaciogenics deposits and modification with paraglacial processes in Wanda Glacier proglacial area, King George Island, Antarctica. The methodology was developed through field activities performed during summers in 2007, 2010 and 2011. The sediments were analyzed to determine the particle size distribution and morphoscopical characteristics. This study presents results of the samples sediment interpretation in Wanda Glacier proglacial area. The sediment analyses provided the discrimination of the glaciogenicssediments and paraglacial modified sediments, and was evidence for environment changes in the study area due to the increase surface atmospheric temperature and liquid precipitation.
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Trenggono, Mukti, Roy Andreas, Amron Amron, Rizqi Rizaldi Hidayat, Hendrayana Hendrayana, Rr Diah Febri Astuti i Cristiana Manullang. "An Assessment of Cilacap Coast's Total Carbonate Sediment Content". Jurnal Kelautan Tropis 24, nr 1 (12.12.2020): 15–24. http://dx.doi.org/10.14710/jkt.v24i1.8849.

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Sediments are particles derived from the dismantling of rocks from the land and pieces of shell and remains of marine organisms that contain organic matter, included carbonate sediment. The total carbonate sediment content was influenced by many factors, such as sediment grain type. This study aimed to determine the carbonate content in sediments and to determine their relationship to the sediment grain characteristic on the Cilacap coast. The sediment's carbonate content used the titration method, while the sediment grain test used a dry filter. Statistical analysis was used to determine the sediment grain characteristic (mean, sorting, skewness, and kurtosis). The results showed that sediments' total carbonate content had a range of 1.93% - 6.23%, with an average of 4.21%. Sediments are dominated by fine sand with very well sorted, very platykurtic, and very fine skewed characteristics. The relationship between sediment grain characteristics and total sediment carbonate content showed a good correlation due to the sorting factor. Other parameters such as mean size and skewness have been shown a low correlation, whereas kurtosis has a shallow relationship with carbonate content.
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Marinho, Rogério Ribeiro, Antonio Fábio Sabbá Guimarães Vieira i Feliciano De Souza Maciel. "Análise Montante-Jusante da Granulometria dos Sedimentos de Fundo e Suspenso do Rio Negro e Tributários (Bacia Amazônica, Brasil)". Revista Brasileira de Geografia Física 14, nr 2 (14.04.2021): 997. http://dx.doi.org/10.26848/rbgf.v14.2.p997-1008.

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O conhecimento das características físicas de sedimentos transportados por grandes sistemas fluviais possui significativa importância para o entendimento de processos geomorfológicos e hidrológicos. O nível de conhecimento dos grandes sistemas fluviais da Amazônia e sua relação com o transporte de sedimentos ainda é limitado, resultando em lacunas de conhecimento sobre a dinâmica da paisagem nesta complexa região. Este trabalho teve como objetivo avaliar a distribuição espacial da granulometria de sedimentos de fundo e suspenso do Rio Negro e tributários. Realizou-se análise da distribuição do tamanho dos sedimentos em seções amostrais localizadas no alto, médio e baixo curso do Rio Negro. Os resultados da análise granulométrica da carga de fundo indicam a predominância de sedimentos com tamanho variando de 0,25 a 1,0 mm (principalmente areia fina, areia média e areia grossa) enquanto no baixo curso as amostram oscilaram de areia fina a partículas lamosas (< 0,50 mm). No Rio Negro os sedimentos suspensos são compostos principalmente de partículas finas de silte (90% menor que 80 µm) com diâmetro mediano (D50) de 25 µm. As características granulométricas apresentadas neste trabalho fornecem subsídios para o entendimento de processos hidrodinâmicos de transporte e deposição dos sedimentos de fundo e suspenso neste gigante sistema fluvial. Upstream-downstream Granulometry Analysis of bed and suspended sediments in the Negro River Basin (Amazon Basin, Brazil)A B S T R A C TThe knowledge of the physical characteristics of sediments transported by large river systems has significant importance for the understanding of geomorphological and hydrological processes. The level of knowledge of the large rivers of the Amazon basin and their relationship with sediment transport is limited, resulting in gaps about the dynamics of the landscape in this complex region. This article analyzes the spatial distribution of granulometry of bed and suspended sediments in the Negro River and tributaries. An analysis of the sediment size distribution was carried out in sample sections located in the upper, middle and lower reaches of the Negro River. The results of the granulometric analysis of the bed load indicate the predominance of sediments with sizes ranging from 0.25 to 1.0 mm (mainly fine sand, medium sand and coarse sand) while in the low course they showed oscillated from fine sand to muddy particles (<0.50 mm). In the Negro River basin the suspended sediments are composed mainly of fine silt particles (90% less than 80 µm) with a median diameter (D50) of 25 µm. The granulometric characteristics presented in this work provide subsidies for the understanding of hydrodynamic processes of transport and deposition of bed and suspended sediments in this huge fluvial system.Keywords: sediment transport, Amazon floodplain, multichannel river, anabranching
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Laut, Lazaro, Maria Virgina Alves Martins, Pierre Belart, Maria Lucia Lorini, Iara Clemente, Leandro Nogueira, Anna Juliace i Luiz Francisco Fontana. "ORGANIC COMPOUNDS AS PROXIES OF THE SEDIMENTARY ENVIRONMENTAL QUALITY OF THE MARICÁ-GUARAPINA LAGOON SYSTEM (SE, BRAZIL)". Journal of Sedimentary Environments 4, nr 2 (15.06.2019): 159–73. http://dx.doi.org/10.12957/jse.2019.43371.

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Bottom sediment is a natural trap for organic matter and different kinds of pollutants. The accumulation of large amount of organic matter gives rise to the eutrophication of the aquatic ecosystems. The analyses of the quantity and quality of the organic matter (biopolymers) help to determine the trophic status of coastal ecosystems. The Maricá-Guarapina Lagoon System (MGLS) is located in Rio de Janeiro and is composed by four connected lagoons: Maricá, Barra, Padre and Guarapina. It has been suffering impacts due to the intense and uncontrolled property speculation. Based on this problem, this study aimed to characterize the organic matter (OM) amount and quality in sediments and the relation with the impacted areas in this lagoon system. The collected sediment samples were analyzed for geochemical data combined with grain size and physical-chemical environmental parameters of the bottom water. Statistical results evidenced that the sedimentary environment of the MGLS is heterogenous. The organic matter supplied to the MGLS is provided from different sources but the autochthonous contribution (phytoplanktonic productivity and vegetal detritus from the mangrove fringe) prevails. The anthropogenic contribution was more evident in Padre Lagoon, where the sediments had relatively low TOC contents (0.1-0.8%). The MGLS is accumulating mainly aged organic matter. The most impacted zones were found in Guarapina, Barra and Maricá lagoons, in bottoms of fine-grained sediments, with relatively high TOC and labile biopolymeric compounds (proteins, carbohydrates and lipids) contents, which should evolve into an ever-increasing stage of eutrophication. COMPOSTOS ORGÂNICOS USADOS COMO INDICADORES DA QUALIDADE AMBIENTAL SEDIMENTAR DO SISTEMA LAGUNAR MARICÁ-GUARAPINA (SE DO BRASIL)ResumoO sedimento de fundo constitui uma armadilha natural para a matéria orgânica e diferentes tipos de poluentes. O acúmulo de grande quantidade de matéria orgânica dá origem à eutrofização dos ecossistemas aquáticos. Estimativas de quantidade e qualidade da matéria orgânica (biopolímeros) podem ajudar a determinar o estado trófico dos ecossistemas costeiros. O Sistema Lagunar de Maricá-Guarapina (MGLS), localizado no Estado do Rio de Janeiro (SE do Brasil), é composto por quatro lagunas interconectadas: Maricá, Barra, Padre e Guarapina. Este sistema tem sofrido impactos devido à intensa e descontrolada especulação imobiliária. Neste contexto, este estudo teve como objetivo caracterizar a quantidade e qualidade de matéria orgânica (MO) dos sedimentos do MGLS. Foram obtidos dados geoquímicos e confrontados com resultados granulométricos em amostras de sedimentos coletados em 22 estações de amostragem e analisados parâmetros físico-químicos da água. Os resultados estatísticos evidenciaram que o ambiente sedimentar do MGLS é heterogêneo. Este sistema recebe matéria orgânica de diferentes fontes, sendo, porém, prevalecente a contribuição autóctone (produtividade fitoplanctônica e detritos vegetais dos manguezais existentes na região). A contribuição antropogênica de matéria orgânica foi mais evidente na Lagoa do Padre, onde os sedimentos apresentaram teores de COT relativamente baixos (0,1-0,8%). As zonas mais impactadas foram encontradas em fundos de sedimentos finos, com teores relativamente elevados de COT e de compostos biopoliméricos lábeis (proteínas, carboidratos e lipídios), nas lagunas de Guarapina, Barra e Maricá. Os resultados obtidos revelam também que o MGLS está acumulando principalmente matéria orgânica envelhecida e permitem prever que as referidas áreas podem evoluir para um estágio de cada vez maior grau de eutrofização.Palavras-chave: Lagunas Costeiras Tropicais. Biopolímeros. Eutrofização. Dinâmica Sedimentar.
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Pinto, Anita Fernandes Souza, José Carlos Martins Ramalho, Leonardo Borghi, Thiago Gonçalves Carelli, Josiane Branco Plantz, Egberto Pereira, Denise Terroso i in. "BACKGROUND CONCENTRATIONS OF CHEMICAL ELEMENTS IN SEPETIBA BAY (SE BRAZIL)". Journal of Sedimentary Environments 4, nr 1 (25.03.2019): 108–23. http://dx.doi.org/10.12957/jse.2019.40992.

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This study intends to evaluate baseline concentrations of chemical elements for unpolluted sediments of Sepetiba Bay (SE Brazil). It analyzes the concentrations of potentially toxic elements (PTE) and other chemical elements (by Inductively Coupled Plasma Mass Spectrometry and Inductively Coupled Plasma Emission Spectrometry) from the upper part of the SP2 drillcore (or 2-SPT-1-RJ; with 50.30 m length), collected on the margins of Sepetiba Bay (at latitude 22° 55'S and longitude 43° 46'W). This core was described and sampled. Textural, mineralogical and geochemical analyses were performed in 17 sediment levels. The sediment layers of interest were selected, considering the period in which they were deposited, before high anthropic influence in the area, and on sediment grain-size. Only the muddy levels were selected, since fine sediments generally tend to have higher elemental concentrations. Foraminiferal occurrence was also analyzed in the selected layers. The results indicate that the studied sediments were deposited in a transitional marine context, after being exposed to multiple sedimentary cycles and weathering. The baseline concentrations, related to natural sediment sources were estimated for As, Cd, Co, Cr, Cu, Ni, Pb, Zn) and P and for other chemical elements. These results are useful in environmental impact assessment not only in the study area, but also for other coastal regions of Rio de Janeiro State. TÍTULO: CONCENTRAÇÕES DE FUNDO DE ELEMENTOS QUÍMICOS NA BAÍA DE SEPETIBA (SE BRASIL) RESUMO:Este estudo pretende avaliar as concentrações de fundo de elementos químicos, em sedimentos não poluídos, na Baía de Sepetiba (Se Brasil). Analisa as concentrações de elementos potencialmente tóxicos (PTE) e outros elementos químicos (por Espectrometria de Massa Plasma Acoplada Indutivamente e Espectrometria de Emissão Plasma Acoplada Indutivamente) da parte superior do testemunho SP2 (ou 2-SPT-1 RJ; com 50,30 m de comprimento), coletado nas margens da Baía de Sepetiba (à latitude 22° 55'S e longitude 43° 46'W). Este testemunho foi descrito e amostrado a cada 5 cm. Análises estruturais, mineralógicas e geoquímicas foram realizadas em 17 níveis de sedimentos. Os níveis de interesse foram selecionados, considerando o período em que foram depositados, antes da alta influência antrópica na área, e no tamanho do grão do sedimento. Apenas os níveis de lama foram selecionados, uma vez que os sedimentos finos tendem geralmente a ter maiores concentrações de elementos quimicos. A ocorrência de foraminíferos foi também analisada nas camadas selecionadas. Os resultados indicam que os sedimentos estudados foram depositados num contexto marinho de transição, após serem expostos a múltiplos ciclos sedimentares e a intemperismo. As concentrações de fundo, relacionadas a fontes naturais de sedimento foram estimadas para As, Cd, Co, Cr, Cu, Ni, Pb, Zn) e P e para outros elementos químicos. Esses resultados são úteis para a avaliação de impacto ambiental, não apenas na área de estudo, mas também em outras regiões costeiras do Estado do Rio de Janeiro. PALAVRAS-CHAVE: Multi-indicadores. Sedimentos. Registros Holocénicos. Litoral. Atlântico Sul.
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Hussain, Mazhar, Daniel Levacher, Nathalie Leblanc, Hafida Zmamou, Irini Djeran-Maigre i Andry Razakamanantsoa. "Testing the Feasibility of Usumacinta River Sediments as a Renewable Resource for Landscaping and Agronomy". Sustainability 15, nr 22 (11.11.2023): 15859. http://dx.doi.org/10.3390/su152215859.

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Fluvial sediment recycling in agronomy is a relatively recent development, as sediment fertilizing potential for crops is unexplored. Freshwater sediments can act as fertilizer and improve the aeration of soils to increase the yield of crops, support vegetation for landscaping, and provide protective cover against erosion. This study focuses on the investigation of the agronomic potential of Usumacinta River sediments. The pH of the sediments is around 8.5, which is slightly alkaline. The organic matter content is low (5.7%). The sodium absorption ratio is 1.2 and the electrical conductivity is low (0.02 mS/cm). These values indicate that sediments are nonsaline, which is essential for the growth of crops and vegetation. The environmental characteristics of sediments show that the heavy metals, polycyclic aromatic hydrocarbon (PAH), and polychlorinated biphenyl (PCB) pollutants in sediments are below the recommended thresholds. In addition, sediments from the Usumacinta River contain minerals such as potassium and iron oxides that are helpful in improving the biological and nutritional characteristics of the soil. Furthermore, the pH, granulometry, mineralogy, organic matter, and carbonate contents of the Usumacinta River sediments are similar to agronomic soils. The Usumacinta River sediment’s potential for agronomy was practically investigated by sowing ryegrass (Lolium perenne) in a greenhouse by using the local climatic conditions and mixing sediments with potting soil. Three soil compositions were used to evaluate the germination and growth of ryegrass. The soil compositions were 100% potting soil (C1), 50% sediments + 50% potting soil (C2), and 100% sediments (C3). The growth rate of ryegrass was evaluated by monitoring the increase in grass height and production of fresh biomass. The germination of ryegrass was similar in all three compositions. The growth of ryegrass and production of fresh biomass were the most significant with 100% potting soil (0.25 kg/m2), somewhat less with sediment mix (0.18 kg·m2), and were the least significant with 100% sediments (0.05 kg/m2). The mixture of potting soil and sediments shows similar growth to 100% potting soil. The ryegrass seed germination, growth, and production of fresh biomass with the mixture of sediments gave encouraging results, and underlined the potential of sediments for soil amendments for agronomy and protective developments, such as limiting riverbank erosion, gardening, and landscaping.
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Alves Martins, Maria Virgínia, Márcia Andréia Da Silva Nunes, Marcio Inacio Alves, Marco Helenio de Paula Alves Coelho, Wellen Fernanda Louzada Castelo, Lucia Maria Lorini, Denise Terroso i in. "GEOCHEMICAL NORMALIZERS APPLIED TO THE STUDY OF THE PROVENANCE OF LITHOGENIC MATERIALS DEPOSITED AT THE ENTRANCE OF A COASTAL LAGOON. A CASE STUDY IN AVEIRO LAGOON (PORTUGAL) / NORMALIZADORES GEOQUÍMICOS APLICADOS AO ESTUDO DE PROVENIÊNCIA DE MATERIAIS LITOGÉNICOS DEPOSITADOS NA ENTRADA DE UMA LAGUNA COSTEIRA. UM ESTUDO DE CASO NA LAGUNA DE AVEIRO (PORTUGAL)". Journal of Sedimentary Environments 3, nr 2 (9.06.2018): 74–92. http://dx.doi.org/10.12957/jse.2018.34815.

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The use of geochemical normalizers has been applied in sedimentological studies in several study contexts, such as pollution, diagenetic and provenance assessment. Selected textural and mineralogical data of 137 surface sediment samples were compared by statistical analyses with geogenic elements concentrations normalized by the Al, Be, Ce, Fe, Fe+Al, Li, Rb and Sc aiming to identify the best normalizer to trace different sources of bottom sediments for the Aveiro Lagoon entrance (NW of Portugal). The study area is heterogenous in terms of hydrodynamics and sedimentary processes.The most commonly applied geochemical normalizer for the sediments elemental concentrations has been the aluminum. However, the statistical analyses evidenced that the best normalizer was the scandium, since Principal Components Analysis results have evidenced that the element/Sc values are largely independent of sediment granulometry and thus have allowed the identification of compositional differences not related to grain size. Statistical analyses have also allowed to discriminate groups of stations that: i) trace the entry and exit of mixed sources sediments of the lagoon due to the action of tidal currents; ii) contain materials provided from the erosion of granitoids present mainly along the Douro River basin, located to the north, and transported southward by coastal drift; iii) encompasse sediments provided from the erosion of the Schist–Greywacke Complex crossed by the Vouga River that drains into the inner central zone of the lagoon and; iv) represent an area of sediment accumulation located near the entrance of Mira Channel, where lithogenic materials, provided by mixed lithologies in addition to organic matter, are being deposited. The results of this work contribute to the knowledge of the sedimentary dynamics of the Aveiro Lagoon, a coastal system which is part of a littoral stretch that is being strongly eroded, due to natural and anthropic causes and should be applicable to other coastal systems with similar characteristics. ResumoO uso de normalizadores geoquímicos tem sido aplicado em estudos sedimentológicos em diversos contextos, como por exemplo, de poluição, avaliação diagenética e de proveniência de sediments. Dados texturais e mineralógicos selecionados de 137 amostras de sedimentos superficiais foram comparados através de análises estatísticas com concentrações de elementos geogênicos normalizadas por Al, Be, Ce, Fe, Fe + Al, Li, Rb e Sc. O estudo visou identificar o melhor normalizador para traçar diferentes fontes de sedimentos de fundo para a entrada da Lagoa de Aveiro (NW de Portugal), uma área heterogênea em termos de processos hidrodinâmicos e sedimentares.O normalizador geoquímico mais comumente aplicado em sedimentos tem sido o alumínio. No entanto, as análises estatísticas evidenciaram que o melhor normalizador foi o escândio, uma vez que os resultados da análise de componentes principal evidenciaram que os valores das razões elemento/Sc são amplamente independentes da granulometria sedimentar e permitiram a identificação de diferenças composicionais não relacionadas com o tamanho do grão. Análises estatísticas também permitiram discriminar grupos de estações que: i) traçam a entrada e saída de fontes mistas de sedimentos da laguna, devido à ação das correntes de maré; ii) contêm materiais provenientes da erosão de granitóides presentes principalmente ao longo da bacia do Rio Douro, localizada a norte, e transportados para sul por deriva litoral; iii) contêm sedimentos provenientes da erosão do Complexo Xisto-grauvaquico atravessado pelo Rio Vouga, que desagua na zona central interna da laguna e; iv) representam uma área de acumulação de sedimentos localizada perto da entrada do Canal Mira, onde materiais litogênicos, fornecidos por litologias diversificadas, além de matéria orgânica, estão sendo depositados.Os resultados deste trabalho contribuem para o conhecimento da dinâmica sedimentar da Laguna de Aveiro, um sistema costeiro que faz parte de um trecho litorâneo fortemente erodido, devido a causas naturais e antrópicas and may be applicable to other coastal systems with similar characteristics.
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Ding, Zhong Jun, Bao Hua Liu, Wei Gao i Xiang Mei Meng. "Analysis of Resistivity Characteristics of Sediments in Northwestern of South Yellow Sea". Applied Mechanics and Materials 568-570 (czerwiec 2014): 8–11. http://dx.doi.org/10.4028/www.scientific.net/amm.568-570.8.

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The resistivity characteristics of sediments are important to analyze marine sedimental environment and material source. A kind of penetration multiple parameter micro-probe which is designed to measure the resistivity of sediment sample in the northwestern of South Yellow Sea. In this paper, shelf sediment resistivity property off northwest of the South Yellow Sea is studied by analyzing the influence factors and relations, for providing valuable information to the marine sedimental environment around this area.
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Vácha, R., J. Čechmánková, J. Skála, J. Hofman, P. Čermák, M. Sáňka i T. Váchová. "Use of dredged sediments on agricultural soils from viewpoint of potentially toxic substances". Plant, Soil and Environment 57, No. 8 (2.08.2011): 388–95. http://dx.doi.org/10.17221/105/2011-pse.

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A set of 29 pond sediments samples was collected. The sediments were separated into three groups, field, village, and forest pond sediments. The sediment samples were taken from pond bottoms and sediment heaps. The sediment characteristics (pH, CEC, Al-exchangeable, C<sub>ox</sub>, humus substances), the content of potentially toxic elements and persistent organic pollutants were analysed in the sediments and compared between sediment groups. The comparison of sediment contamination with Czech legislation for sediment use in agriculture was conducted. The village sediments were more loaded by potentially toxic elements and persistent organic pollutants than the others. The pH value of sediments was considered as the properties regulating the retention of potentially toxic elements and their mobility (Al, Cd, Zn). Polycyclic aromatic hydrocarbons (PAHs) were the most problematic POPs group in the sediments. The correlation showed poor dependency of POPs (especially PAHs) content on the content and quality of sediment organic matter.
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Rozprawy doktorskie na temat "Sediments"

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Sherwood, Christopher R. "Measurements and modeling of suspended-sediment transport on the northern California continental shelf /". Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/11014.

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Abdullayev, Elshan. "Reconstruction of provenance and climatic conditions in the source areas based on fine-grained sediments from the Pliocene Productive Sereis, western South Caspian Basin". Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-160022.

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The study examines sediments of the Productive Series from the western South Caspian Basin. The main goal of this work is to reconstract provenance of the sediments and its relation to the climatic variability during the deposition of the Productive Series. The Productive Series is divided into a lower and upper division. The Russian Platform was the main sediment source area for the Lower Division. Three different sediment source areas were determined for the Upper Division: the Russian Platform was sediment source area for the Absheron Peninsula; the Greater Caucasus was the main sediment source area for the South Absheron Offshore Zone and the Lesser Caucasus was the main sediment source area for the Baku Archipelago. The sediments of the Lower Division have variable smectite and illite concentrations which indicate climate change between humid and arid conditions in the Russian Platform. The Upper Division of the Productive Series from the Absheron Peninsula is characterised by high amounts of illite. It suggests physical weathering under arid climatic condition on the Russian Platform at the time of deposition. Variation of the smectite and illite assemblages of the Upper Division from the South Absheron Offshore Zone probably indicate that the climate alternated between humid and arid conditions in the Greater Caucasus. The low amount of the TOC ratios in the Productive Series are associated with arid climatic condition in the Russian Platform and the Greater Caucasus. The much higher TOC/TN ratios (>35) indicate that sediments of the Productive Series were impacted by oil. However the low TOC/TN ratios (<12) in some intervals of the Productive Series suggest an aquatic source for an organic matter.
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Godoi, Ana Carolina. "Remineralização da matéria orgânica sedimentar em resposta à simulação de processos oceanográficos". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/21/21134/tde-09042014-174007/.

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Os sedimentos marinhos são receptores finais de vários compostos da coluna de água, possuindo uma participação ativa nos ciclos biogeoquímicos. Comunidades microbianas possuem um papel crucial nestes ciclos, sendo responsáveis por grande parte da remineralização da matéria orgânica em sedimentos superficiais. Foram realizados dois experimentos com simulações de processos oceanográficos em microcosmos: Enriquecimento Orgânico, testando a diferença entre a chegada de fitoflagelados e diatomáceas no sedimento e Ressuspensão, simulando a passagem de frente fria. Foram analisados os compostos referentes à qualidade e quantidade da matéria orgânica sedimentar, assim como o fluxo de nutrientes da interface água-sedimento. No Experimento Enriquecimento, as diferentes algas causaram respostas distintas nos processos de degradação da matéria orgânica, aumentando a qualidade e o metabolismo das comunidades presentes, além de modificar os fluxos de nutrientes, sendo notada uma resposta mais rápida nos mecanismos de degradação devido à adição do fitoflagelados. No Experimento Ressuspensão, o distúrbio físico ocasionou uma resposta imediata e significativa na liberação dos nutrientes do sedimento para a interface água-sedimento e alterações nas concentrações de ácidos graxos, principalmente nos dois primeiros dias após a simulação. Logo, os diferentes eventos oceanográficos simulados comprovaram sua influência frente aos processos biogeoquímicos, principalmente na disponibilidade de ácidos graxos e na liberação de nutrientes para a água sobrejacente
Marine sediments are the final receivers of many organic compounds from the water column, playing an important role in biogeochemical cycles. Microbial communities are important to these cycles as they remineralize organic matter within surface sediments. Microcosm experiments were conducted to simulate two important oceanographic processes: Organic Enrichment, to test differences between sinking patterns of phytoflagellates and diatoms and Resuspension, simulating the passage of a cold front. The quality and amount of the organic matter was assessed, as well as the nutrient flow between the sediment-water interface. In the Enrichment Experiment, distinctive responses in the degradation processes were noted between treatments where the addition of phytoflagellates increased the quality of the organic matter, caused faster metabolism communities present in the sediment, and modify the patterns of nutrient flux rates. In the Resuspension Experiment, the physical disturbance caused an immediate and significant release of nutrients from the sediment to the sediment-water interface and changed the in the concentrations of fatty acid content most notably during two days after the resuspension event. Thus, the different simulated oceanographic events influenced biogeochemical processes, particularly in the availability of fatty acids and the release of nutrients to the overlying water
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Sell, Karen S. "Temporal influences of seasonal hypoxia on sediment biogeochemistry in coastal sediments". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/1142.

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Bottom water hypoxia and its influence on the environment have been topics of increasing concern for many coastal regions. This research addresses both spatial and temporal variability in sediment biogeochemistry at the southeastern region of Corpus Christi Bay, TX, where seasonal (summer) hypoxia occurs. Traditional techniques for determination of a variety of dissolved and solid components, benthic oxygen demand, and sulfate reduction rates were augmented by measurements using solid state microelectrodes to simultaneously determine concentrations of dissolved O2, Mn2+, Fe2+, and [sigma]H2S in multiple small - interval (1 mm) depth profiles of sediment microcosms. Oxygen concentrations in the overlying water were manipulated in the sediment microcosms and electrode depth profile measurements were made over ~ 500 hours of experimentation. Laboratory and field microelectrode results were in good agreement for both norm - oxic and anoxic time periods. Results indicated that iron (Fe2+) and sulfide ([sigma]H2S) were the redox reactive species in these sediments. During hypoxic conditions an upward migration of dissolved Fe2+and [sigma]H2S through the sediment column and, at times, into the overlying water was observed as the dissolved oxygen concentrations decreased. A corresponding decline in the vertical extent of these redox species occurred when the overlying water was re-oxidized. When both dissolved iron and sulfide coexisted, FeS minerals were formed in the sediment, preventing sulfide diffusion into the overlying water. However, after a long duration of hypoxia (> 200 hours) this buffering capacity was exceeded and both iron and sulfide penetrated into the overlying waters. Results indicated that iron may have a greater influence on hypoxia than sulfide because its concentration in the overlying waters during induced hypoxia was an order of magnitude greater than those of sulfide. Moreover, in the southeastern region of the Bay, where mixing was minimal and the water column was shallow, the sediments alone may have caused the onset of the hypoxic event in a relatively short time period (< 5.5 days). These results demonstrated that in shallow marine environments where seasonal hypoxia occurs, such as Corpus Christi Bay, the associated major changes that take place in the sediment biogeochemistry must be included in benthic - pelagic models for overlying water hypoxia.
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Filho, Ricardo Wagner Reis. "Avaliação ecotoxicológica do sedimento da Represa do Lobo (SP), em mesocosmos submetidos aos metais cobre e cromo". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-08082016-104419/.

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Experimentos em mesocosmos, por se tratarem de estudos in-situ, possibilitam extrapolar para o campo, investigações realizadas em menor escala, com maior seguridade. Em fevereiro de 2002, foram instalados às margens da represa do Lobo (22º15\'S e 47º49\'W) nove mesocosmos, construídos com plástico (PVC) em forma de hexágono com 2 metros de altura, com fundo aberto em contato com o sedimento e volume variando entre 4,5 e 5,1 m3, em função da declividade do terreno. De acordo com a resolução 20/86 do Conselho Nacional do Meio Ambiente, as concentrações máximas permitidas para os metais cobre (0,02 mg/L) e cromo (0,5 mg/L) em corpos d\'água Classe 2 foram adicionadas aos mesocosmos, originando-se triplicatas, adotando-se outros três mesocosmos como controles. O objetivo principal deste trabalho foi verificar as possíveis alterações no ambiente sedimento, particularmente o enriquecimento e a indução de toxicidade, em função da adição dos metais mencionados. Para tanto, amostras foram coletadas através de dragas e testemunhos nos tempos 0 dia (antes da contaminação), 10 dias, 20 dias e 30 dias após a contaminação (final do experimento). Em seguida, as amostras foram preparadas e submetidas às análises físicas e químicas, caracterização da macrofauna bentônica e diversos ensaios toxicológicos. A partir dos dados gerados, efetuou-se o estudo integrativo da tríade de qualidade de sedimentos. Os resultados obtidos mostraram um discreto aumento na concentração total dos metais cobre e cromo nos sedimentos dos mesocosmos contaminados em comparação aos controles, sendo verificada diminuição na abundância de organismos bentônicos e efeitos tóxicos sobre os organismos-teste submetidos a estes sedimentos. As respostas da tríade foram essenciais para a caracterização da qualidade dos sedimentos dos mesocosmos controle em relação aos dos mesocosmos contaminados.
In-situ mesocosms experiments allow the extrapolation of laboratory data to the field with high reliability. In the present study, nine hexagonal PVC mesocosms with 2 m height and 4.5 to 5.1 m3 volume were installed in contact with the sediment near the Lobo reservoir dam (22º15\'S e 47º49\'W) in february of 2002. In accordance with the National Environmental Council (CONAMA) 20/86 resolution for Class 2 water bodies, the maximum allowed concentrations of copper (0,02 mg/L) and chromium (0,5 mg/L) were added to the mesocosms (triplicate), and three other ones were used as controls. The main purpose of this study was to evaluate the possible changes in the sediment environment, particularly the enrichment and induction of toxicity, by the contamination of these metals. The sediment was sampled by means of Eckman-Birge and core samplers on the 0 (before the contamination), 10th, 20th and 30th days (end of the experiment). Afterwards, physical and chemical analyses, benthic macrofauna characterization and several toxicity assays were conducted with the samples. In order to better evaluate these results, the sediments quality triad was considered. A discrete increase in the total concentration of copper and chromium was observed in the sediments of the contaminated mesocosms when compared to the controls, as well as a reduction in the abundance of benthic organisms and toxic effects over the organisms tested with these sediments. The triad responses were essential for quality characterization of the control mesocosms sediments in comparison with the contaminated ones.
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Bornemann, André, Thomas C. Brachert i Werner Ehrmann. "SEDIMENT 2011 Sediments: Archives of the Earth System: SEDIMENT 2011Sediments: Archives of the Earth System". ?, 2011. https://ul.qucosa.de/id/qucosa%3A11218.

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This volume comprises ninety-one contributions to the Sediment 2011 conference of the Central European section of the Society for Sedimentary Geology (SEPM-CES) and the Geologische Vereinigung (GV) at the University of Leipzig held in June 2011. The central theme of this meeting was “Sediments: Archives of the Earth System” in order to bring together young and established researchers from all fields of soft-rock geology and beyond to shape a stimulating interdisciplinary program on the role of sediments in understanding the System Earth and the evolution of paleoenvironments and climate through time.
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Suedel, Burton C. (Burton Craig). "Sediment Characteristics and Bioavailability of Sorbed Neutral Organic Compounds". Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc500652/.

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Several sediment characteristics were analyzed to determine their suitability for use as potential normalization factors for the bioavailability of neutral organic compounds sorbed to sediments. Percent organic carbon, cation exchange capacity and particle surface area were measured sediment characteristics that varied sufficiently to encompass the range in observed sediment toxicity. Laboratory sediment toxicity test data using fluoranthene suggest that there is no biologically significant correlation between sediment toxicity and sediment characteristics (organic carbon, cation exchange capacity, particle size distribution, particle surface area). Fluoranthene amended sediments with similar organic carbon contents do not yield similar toxicities due to sorbed fluoranthene and thus do not support the organic carbon normalization approach for evaluating sediment quality or for sediment criteria development.
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Piqué, Altés Gemma. "Analysis of hydro-sedimentary processes and impacts affecting river basins and channels". Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/405448.

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Aquesta tesi estudia la dinàmica hidro-sedimentària de rius mediterranis, tant ‘naturals’ com regulats per preses. Amb aquest objectiu, s’ha realizat un estudi a escala multi-temporal i multi-espacial, que inclou treball de camp en trams de riu representatius, l’anàlisi de dades a nivell de conca, i experiments en canals de laboratori. L’alteració hidrològica aigües avall dels embassaments s’ha observat a diferents escales temporals, afectant notablement la magnitud i freqüència de les crescudes. A nivell sedimentari, s’observa un dèficit de sediments, fet que facilita l’establiment de biofilm i que, a la vegada, afavoreix l’estabilització del llit del riu. A més, l’emmagatzematge temporal de sediments a la llera modula el balanç i regula l’entrada de sediments en embassaments. La tesi mostra els efectes d’un conjunt d’activitats antròpiques en procesos fluvials i com això altera les interaccions bio-físiques del riu, i posa èmfasi en la necessitat d’una gestió contínua per la preservació dels ecosistemes fluvials.
Esta tesis estudia la dinámica hidro-sedimentaria de ríos mediterráneos, tanto ‘naturales’ como regulados por presas. Con este objetivo, se ha realizado un estudio a escala multi-temporal y multi-espacial, que incluye trabajo de campo en tramos de río representativos, análisis de datos a nivel de cuenca, y experimentos en canales de laboratorio. La alteración hidrológica aguas abajo de los embalses se ha observado a diferentes escalas temporales, afectando notablemente la magnitud y frecuencia de las crecidas. A nivel sedimentario, se observa un déficit de sedimentos, lo que facilita el establecimiento de biofilm y, a la vez, favorece la estabilización del lecho del río. Además, el almacenamiento temporal de sedimentos en el lecho modula el balance y regula la entrada de sedimentos en embalses. La tesis muestra los efectos de un conjunto de actividades antrópicas en procesos fluviales y en la alteración en las interacciones bio-físicas del río, y enfatiza la necesidad de una gestión continua para la preservación de los ecosistemas fluviales.
This PhD thesis studies hydro-sedimentary dynamics in Mediterranean rivers, both in ‘natural’ and in dammed rivers. For this purpose, a multi-temporal and spatial research was carried out, including field measurements in representative river reaches, data analysis at the basin scale, and experiments in artificial streams. The hydrological alteration downstream from dams was documented at different temporal scales, notably affecting the magnitude and frequency of floods. Regarding sediments, a severe deficit was observed below dams, a fact that facilitates the establishment of biofilm which, in turn, favours river bed stabilisation. Moreover, the study shows how in-channel storage influences the river sediment budget and regulates sediment input in reservoirs. The thesis examines the effects of a suit of human activities on fluvial processes and how this alter rivers’ bio-physical interactions, and emphasises the need of continuous monitoring of all these processes to achieve a sound management of fluvial ecosystems.
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Denys, Frank. "Transverse transport of suspended sediment across the main channel - floodplain shear boundary /". Link to the online version, 2007. http://hdl.handle.net/10019/415.

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Battisto, Grace M. "Field Measurement of Mixed Grain Size Suspension in the Nearshore Under Waves". W&M ScholarWorks, 2000. http://web.vims.edu/library/Theses/Battisto00.pdf.

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Książki na temat "Sediments"

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Drake, Thomas G. Compilation of suspended-load point-transport theories. [Vicksburg, Miss: U.S. Army Engineer Waterways Experiment Station, 1995.

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Hay, Bernward J. Particle flux in the western Black Sea in the present and over the last 5000 years: Temporal variability, sources, transport mechanisms. Woods Hole, Mass: Woods Hole Oceanographic Institution, 1987.

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Olsen, Marianne, Karina Petersen, Alizee P. Lehoux, Matti Leppänen, Morten Schaanning, Ian Snowball, Sigurd Øxnevad i Espen Lund. Contaminated Sediments. Copenhagen: Nordic Council of Ministers, 2019. http://dx.doi.org/10.6027/tn2019-514.

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Kassim, Tarek A., i Damià Barceló, red. Contaminated Sediments. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-88014-1.

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Pye, K., i N. Lancaster, red. Aeolian Sediments. Oxford, UK: Blackwell Publishing Ltd., 1993. http://dx.doi.org/10.1002/9781444303971.

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Riding, Robert E., i Stanley M. Awramik, red. Microbial Sediments. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04036-2.

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Brodzikowski, K. Glacigenic sediments. Oxford: Elsevier, 1991.

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P, Bordas M., Walling D. E, International Association of Hydrological Sciences. i Brazil. Ministério da Educação e Cultura., red. Sediments budgets. Wallingford, Oxfordshire: IAHS, 1988.

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Brodzikowski, Krzysztof. Glacigenic sediments. Amsterdam: Elsevier, 1991.

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Ramsey, Greig. River sediments. Hauppauge NY: Nova Science Publishers, 2009.

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Części książek na temat "Sediments"

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Huggett, Richard John. "Sediments". W Climate, Earth Processes and Earth History, 77–109. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76268-0_4.

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Dalezios, Nicolas R., Saeid Eslamian, Kaveh Ostad-Ali-Askari, Shahab Rabbani i Ali Saeidi-Rizi. "Sediments". W Selective Neck Dissection for Oral Cancer, 1–2. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-12127-7_254-1.

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Bauer, Andreas, i Bruce D. Velde. "Sediments". W Geochemistry at the Earth’s Surface, 249–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-31359-2_6.

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Effler, Steven W., Martin T. Auer, Ned Johnson, Michael Penn i H. Chandler Rowell. "Sediments". W Springer Series on Environmental Management, 600–666. New York, NY: Springer New York, 1996. http://dx.doi.org/10.1007/978-1-4612-2318-4_8.

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Murad, Enver, i John Cashion. "Sediments". W Mössbauer Spectroscopy of Environmental Materials and Their Industrial Utilization, 189–206. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4419-9040-2_6.

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Goldberg, Paul, i Richard I. Macphail. "Sediments". W Practical and Theoretical Geoarchaeology, 11–27. Malden, MA USA: Blackwell Publishing Ltd., 2013. http://dx.doi.org/10.1002/9781118688182.ch1.

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Mangelsdorf, Joachim, Karl Scheurmann i Fritz-Heinz Weiß. "Sediments". W River Morphology, 25–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-83777-7_4.

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Dalezios, Nicolas R., Saeid Eslamian, Kaveh Ostad-Ali-Askari, Shahab Rabbani i Ali Saeidi-Rizi. "Sediments". W Encyclopedia of Earth Sciences Series, 818–19. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73568-9_254.

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Sen, Gautam. "Sediments". W Petrology, 277–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38800-2_13.

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Cairns, John. "The Influence of Contaminated Sediments on Sustainable Use of the Planet". W Contaminated Sediments, 1–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/698_5_110.

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Streszczenia konferencji na temat "Sediments"

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Maherzi, Walid, Mahfoud Benzerzour, Nor-Edine Abriak i Ahmed Senouci. "Marine Dredging Sediments Valorization in Self-Compacting Concretes". W The 2nd International Conference on Civil Infrastructure and Construction. Qatar University Press, 2023. http://dx.doi.org/10.29117/cic.2023.0086.

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Rock and eroded soil are transported by wind, tide, and human action (development works), and deposited as sediment in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits and restore the natural environment for proper port functioning. At the national level, the maintenance of the 6,500-kilometer French coastline would require the extraction of about fifty million cubic meters of marine sediment every year. These dredged sediments have been used in civil engineering applications for about ten years, in order to reduce their economic and environmental impact. The proposed study addresses the potential use of sediments to produce accropode blocks for maritime public works applications. It consists in developing concrete mixtures using dredged marine sediment treated to protect against erosion. A study of material characterization, optimization of the composition of the concrete formulation, as well as a determination of the mechanical, physical and durability properties of the concrete were necessary to validate the technical feasibility of this new solution. Around 700 small accropode blocks were then prepared to better analyze the structure stability against swell effects. The obtained results show that the sediments could not produce Self Compacting Concrete (SCC). However, sediment treatment with 6% by weight of cement has enabled the production of SCC. It is worth noting that the use of superplasticizer was essential to ensure concrete workability. Increasing the cement percentage has also improved the composite workability. Finally, a concrete compressive strength greater than 40 MPa has been achieved when using 300 kg/m3 of treated sediments.
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Catianis, Irina, Adriana Maria Constantinescu, Dan-Lucian Vasiliu, Bogdan-Adrian Ispas i Dumitru Grosu. "PHYSICAL AND CHEMICAL CHARACTERISTICS OF TATARU AND MERHEI LACUSTRINE SEDIMENTS, FROM THE DANUBE DELTA, ROMANIA". W 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/5.1/s20.042.

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The quality and quantity of delta lakes� sediment depend on fluvial input and in-situ bio-geo-chemical processes. The present study investigates the quality of lacustrine sediments collected from two lakes - Tataru and Merhei, situated in different hydrodynamic environments within the Danube Delta, Romania, but both connected to fluvial input of water and sediment of the Danube. The following physical and chemical analyses have been carried out on several lake-bottom sediment samples: the main lithological components (total organic matter-TOM%, total carbonates-CAR% and siliciclastic fraction-SIL%), particle size analysis and technophilic element contents. The lithological analysis reveals a considerable variation related to the TOM%, CAR% and SIL% fractions. From this perspective, the investigated lacustrine sediments are generally characterized as organic-rich sediments (endogenous input). The grain size analysis shows the predominance of sandy silt sediments in both lakes. The data regarding the content of technophilic elements in the bed-sediment samples is given in comparison with their natural geochemical background reference value and their acceptable limits provided by the national reference standard. The general characterization of the investigated sediments reveals slight differences among the two investigated lakes in terms of the sediment input from the Danube River. The acquired results contribute to improve the knowledge about physical and chemical characteristics of lacustrine sediments and to plan management strategies of the deltaic lakes for future conservation perspectives, considering the great international importance of the Danube Delta Biosphere Reserve.
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Mohr, Henning, Scott Draper i David White. "Free Field Sediment Mobility on Australia’s North West Shelf". W ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11490.

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Under cyclonic conditions, sediment on the North West Shelf (NWS) of Australia may become mobile in shallow water due to classical sediment transport or local liquefaction, and this can affect, for example, the on-bottom stability of subsea pipelines. In this paper, three calcareous sediments sampled from the NWS are analysed, together with realistic metocean data, to illustrate this potential for sediment mobility on the NWS. Specifically, experiments are performed in a recirculating flume (known as an O-Tube) to measure the erosional behaviour and an additional series of experiments are performed using a shaking table, on which each of the sediments have been liquefied and excess pore pressure measurements recorded to back calculate the consolidation coefficient. Soil characterisation data, threshold velocity measurements and shaking table results have then combined to illustrate the potential for sediment mobility for each of the NWS sediments. Best practice models are used to calculate wave and current combined shear stress at the seabed and excess pore pressure accumulation. We find that for these sediments, freshly deposited in laboratory samples, mobility due to sediment transport or liquefaction is very likely in cyclonic conditions on the NWS. Liquefaction is most likely for loosely packed silt, whilst sediment transport is most likely for sand. However, we also show that in more extreme cyclonic conditions there are a subset of sediments that can become mobile due to both sediment transport and liquefaction.
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Beemer, Ryan D., Alexandre N. Bandini-Maeder, Jeremy Shaw, Ulysse Lebrec i Mark J. Cassidy. "The Granular Structure of Two Marine Carbonate Sediments". W ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77087.

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Calcareous sediments are prominent throughout the low-latitudinal offshore environment and have been known to be problematic for offshore foundation systems. These fascinating soils consist largely of the skeletal remains of single-celled marine organisms (plankton and zooplankton) and can be as geologically complex as their onshore siliceous counter parts. To enable an adequate understanding of their characteristics, in particular, their intra-granular micro-structure, it is important that geotechnical engineers do not forget about the multifaceted biological origins of these calcareous sediments and the different geological processes that created them. In this paper, the 3D models of soils grains generated from micro-computed tomography scans, scanning electeron microscope images, and optical microscope images of two calcareous sediments from two different depositional environments are presented and their geotechnical implications discussed. One is a coastal bioclastic sediment from Perth, Western Australia that is geologically similar to carbonate sediments typically used in micro-mechanics and particle crushing studies in the literature. The other is a hemipelagic sediment from a region of the North West Shelf of Australia that has historically been geotechnically problematic for engineers. The results show there is a marked difference between coastal bioclastic and hemipelagic sediments in terms of geological context and the associated particle micro-structures. This brings into question whether a coastal bioclastic calcareous sediment is a good micro-mechanical substitute for a hemipelagic one.
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Vrålstad, Torbjørn, Ragnhild Skorpa i Arild Saasen. "Rheological Properties of Barite Sediments in Water-Based Drilling Fluids". W ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78695.

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When a drilling fluid column remains static over a timeframe of several years, the drilling fluid separates into different sediment phases due to gravity separation. These heavy sediments, entitled “settled barite”, are the cause of significant operational problems several years after drilling. An important problem caused by settled barite occurs when performing casing cut-and-pull operations during slot recovery and well abandonment: the casing is “stuck” due to the sediments in the annulus outside the casing. The consistency and rheological properties of the sediments determine how easily the casing is removed. In this paper, we report a preliminary study were we have artificially prepared gravity sediment phases for two different types of water-based drilling fluids; one KCl/polymer-based fluid and one bentonite-based fluid. By studying the rheological properties of the obtained sediment phases, we see that there are considerable differences between the sediments for these different drilling fluids.
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Chi, Sang-Bum, Wonnyon Kim, Cheong-Kee Park, Chanmin Yoo, Youngtak Ko i Jai-Woon Moon. "Relationship Between Manganese Nodule Distribution and Deep-Sea Sediment Properties in the Northeastern Pacific". W ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83773.

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In order to identify a potential relationship between the spatial distribution of Mn-nodule and deep-sea sediment properties in the Clarion-Clipperton fracture zone of the northeastern Pacific, physico-chemical properties of deep-sea sediments and photos of sea-floor are analyzed. In general, sediment types in the area show dramatic changes with latitude. Compared to the middle sector (8–12°N) covered with biogenic siliceous sediments, the northern (16–17°N) and southern (5–6°N) areas are dominated by pelagic red clays and calcareous sediments, respectively. Such a difference in sediment types probably produces regional-scale variations in Mn-nodule occurrence with latitude (5–17°N) along longitude (131.5°W). According to the photographic examination, manganese nodules are well exposed on the sea floor in the latitude of >8°N. In connection with the dominant oceanic environment, such observation indicates that calcareous sediments cover the diagenic nodules due to higher primary productivity and sedimentation rate in the latitude of <8°N. In addition, sediments in the latitude of 8–12°N show relatively high shear strength. Considering the operation of miner and environmental effect, highly consolidated B2 and C1 areas (8–12°N), showing higher nodule contents and relatively lower primary productivity, are the most plausible site for commercial mining.
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Zhang, Ning, Anpeng He, Jeff Corbino, Paul Schroeder i Johnathan Bolton. "The Impacts of Confined Disposal Facilities on Calcasieu Ship Channel Sedimentation". W ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16160.

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The confined disposal facilities (CDFs) are the areas along Calcasieu Ship Channel to store dredged sediments from the ship channel. As the sediments settle in the CDFs, the low concentration sediment flows are discharged into the open water adjacent to the CDFs. The paper demonstrates flow and sediment transport characteristics in the open water due to the CDF discharge. The sediment distributions in all three dimensions in the water are revealed. The lake current effects were also investigated. A commercial CFD package ANSYS-FLUENT is used to simulate all cases in this study.
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Ong, Muk Chen, Lars Erik Holmedal i Dag Myrhaug. "Numerical Computation of Suspended Sediment Around a Marine Pipeline Close to the Flat Seabed". W ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49111.

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The purpose of this paper is to investigate suspended sediment transport around a marine pipeline near the seabed by solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with the standard k-ε model. High Reynolds number flow simulations are considered in the present study. The suspended sediments are seeded upstream of the pipeline. Particle trajectories of the suspended sediments downstream of the pipeline have been visualized by using a Lagrangian approach. Effects of the gap (i.e. the normal distance between the pipeline and the seabed) and the sediment weight (i.e. taking into account sediment settling velocity) have been investigated and discussed.
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Ye, Zhihui, Liang Cheng i Zhipeng Zang. "Experimental Study of Erosion Threshold of Reconstituted Sediments". W ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-50067.

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Understanding of fundamental erosion characteristics of seabed sediments on which pipelines and other structures are founded is critical for the design of these facilities. The erosion threshold condition of cohesive sediments is not well understood because of the complexity and variability of natural sediments. Most of the existing methods for evaluating the erosion behaviours of seabed sediment are often applicable to the certain particular sediment types and test conditions. There appears to be a need for more research efforts in this area. In present research, the threshold of motion of four moderately consolidated mixtures was tested under unidirectional currents using a testing facility. Three threshold shear stress increase modes were observed, including initial increase mode, steady increase mode and equilibrium mode as mass content of mud Pm increases. A dimensionless threshold shear stress τ* is proposed to quantify the shear strength of these reconstituted mixtures, coupled with variation of coarse particle size. Finally, a predicting model is proposed to illustrate the trend of erosion threshold of the four mixtures as a function of mud weight content. Further understanding of erosion threshold can rely on the various consolidation conditions and different coarse and fine materials inputted in the mixture.
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ROELVINK, DANO. "ADDRESSING LOCAL AND GLOBAL SEDIMENT IMBALANCES: COASTAL SEDIMENTS AS RARE MINERALS". W Coastal Sediments 2015. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814689977_0002.

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Raporty organizacyjne na temat "Sediments"

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Kuehl, Steven A. Extension of Sediment Geochronology to Coarse-Grained Sediments. Fort Belvoir, VA: Defense Technical Information Center, wrzesień 2005. http://dx.doi.org/10.21236/ada572615.

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Alokhina, Tetiana, i Vadym Gudzenko. Distribution of radionuclides in modern sediments of the rivers flowing into the Dnieper-Bug Estuary. EDP Sciences, 2021. http://dx.doi.org/10.31812/123456789/4617.

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The article presents the results of large-scale studies of the content and distribution of natural and man-made radionuclides in the sediments of the rivers flowing into the Dnieper-Bug estuary. The article also presents the results of the granulometric analysis of the surveyed water bodies. The data about natural radioactive elements in the sediments rivers flowing into the Dnieper-Bug estuary obtained in this research are demonstrated moderate specific activity, which, however, clearly correlates with the granulometric composition of sediments. The 137Cs determined by us is contained in the sediments of all studied water bodies and the places of it greatest concentration coincide with the areas in which the sediment is represented mainly by the pelitic fraction. The data obtained in this research can serve as a baseline data in natural radionuclides concentration in sediments rivers flowing into the Dnieper-Bug estuary. The obtained data can also be used for further monitoring of the specific activity of man-made radionuclides, in particular 137Cs.
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Wilkins, Justin, Andrew McQueen, Joshua LeMonte i Burton Suedel. Initial survey of microplastics in bottom sediments from United States waterways. Engineer Research and Development Center (U.S.), wrzesień 2021. http://dx.doi.org/10.21079/11681/42021.

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Given the reported extent of microplastics in the aquatic environment, environmentally relevant exposure information for sediments dredged by the US Army Corps of Engineers will lend context to the risks posed by this contaminant during dredging. We measured the occurrence, abundance, and polymer composition of microplastics in sediments collected from nine dredged waterways and two non-dredged reference areas. The number of particles in sediment samples ranged from 162 to 6110 particles/kg dry wt., with a mean of 1636 particles/kg dry wt. Fragments were the most prevalent shape observed among the 11 study sites (100% frequency of occurrence), followed by fibers (81%), spheres (75%), foams (38%) and films (34%). Based on analyses of chemical composition of the particles using Fourier transform infrared spectroscopy, polyethylene:propylene was the most common polymer type observed. Consistent with results presented by other investigators microplastic concentrations and polymer types in bottom sediments in this study were also aligned with the most widely used plastics worldwide.
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Kargl, Steven G. Bubbles in Sediments. Fort Belvoir, VA: Defense Technical Information Center, wrzesień 1997. http://dx.doi.org/10.21236/ada627572.

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Kargl, Steven G. Bubbles in Sediments. Fort Belvoir, VA: Defense Technical Information Center, wrzesień 1999. http://dx.doi.org/10.21236/ada629693.

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Piercy, Candice, Brandon Boyd, Emily Russ i Kyle Runion. Systematic beneficial use of dredged sediments : matching sediment needs with dredging requirements. Engineer Research and Development Center (U.S.), wrzesień 2022. http://dx.doi.org/10.21079/11681/45443.

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This technical note (TN) will outline a framework to identify beneficial and cost-effective coastal beneficial use of dredged sediment (BUDS) projects. Creation of a BUDS framework that can be applied at scale will promote sustainable BUDS practices, facilitating the delivery of flood risk management, social, and environmental benefits while still fulfilling the US Army Corps of Engineers (USACE) navigation mission. This proactive forecasting approach uses multi-criteria decision analysis (MCDA) and optimization tools to balance tradeoffs between navigation dredging and BUDS goals over project-scale timespans. The proposed framework utilizes available tools to quantify ecological system evolution and current and future dredging needs to develop a systems-level approach to BUDS. Required data include current and future information on (1) existing and planned natural and created aquatic ecological systems, which may include natural and nature-based features (NNBFs), (2) dredging requirements and costs, and (3) aquatic system physical and environmental data.
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Lim, Raymond, i Joseph L. Lopes. Acoustics of Underwater Sediments. Fort Belvoir, VA: Defense Technical Information Center, wrzesień 1997. http://dx.doi.org/10.21236/ada629263.

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Priestas, Anthony, Brian McFall i Katherine Brutsche. Performance of nearshore berms from dredged sediments : validation of the Sediment Mobility Tool. Coastal and Hydraulics Laboratory (U.S.), grudzień 2019. http://dx.doi.org/10.21079/11681/34756.

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Ding, Yan, Sung-Chan Kim, Rusty L. Permenter, Richard B. Styles i Jeffery A. Gebert. Simulations of Shoreline Changes along the Delaware Coast. Engineer Research and Development Center (U.S.), styczeń 2021. http://dx.doi.org/10.21079/11681/39559.

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This technical report presents two applications of the GenCade model to simulate long-term shoreline evolution along the Delaware Coast driven by waves, inlet sediment transport, and longshore sediment transport. The simulations also include coastal protection practices such as periodic beach fills, post-storm nourishment, and sand bypassing. Two site-specific GenCade models were developed: one is for the coasts adjacent to the Indian River Inlet (IRI) and another is for Fenwick Island. In the first model, the sediment exchanges among the shoals and bars of the inlet were simulated by the Inlet Reservoir Model (IRM) in the GenCade. An inlet sediment transfer factor (γ) was derived from the IRM to quantify the capability of inlet sediment bypassing, measured by a rate of longshore sediments transferred across an inlet from the updrift side to the downdrift side. The second model for the Fenwick Island coast was validated by simulating an 11-y ear-long shoreline evolution driven by longshore sediment transport and periodic beach fills. Validation of the two models was achieved through evaluating statistical errors of simulations. The effects of the sand bypassing operation across the IRI and the beach fills in Fenwick Island were examined by comparing simulation results with and without those protection practices. Results of the study will benefit planning and management of coastal sediments at the sites.
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Moore, David, Damarys Acevedo-Acevedo i Philip Gidley. Application of clean dredged material to facilitate contaminated sediment source control. Engineer Research and Development Center (U.S.), wrzesień 2022. http://dx.doi.org/10.21079/11681/45342.

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Navigation channels, turning basins, and other US Army Corps of Engineers (USACE)–managed navigation infrastructure often serve as repositories for contaminated sediment from off-site sources. As much as 10% of the material that USACE dredges on an annual basis is contaminated such that it requires additional and more costly management (for example, rehandling and placement in managed confined disposal facilities). Presence of contaminated sediments constrain potential management options resulting in additional costs and opportunity loss from the inability to beneficially use the material. One potential solution is applying clean dredged material to stabilize and isolate contaminated sediment sources, preventing further transport and introduction to USACE-managed infrastructure. This document summarizes a comprehensive literature review of laboratory and field case studies relevant to using clean dredged material to isolate or stabilize contaminated sediments, focusing on the physical, chemical, and biological parameters critical to establishing its feasibility and long-term effectiveness. Potentially effective engineering control measures were also reviewed where erosion and site hydrodynamics are facilitating the transport of contaminated sediments to USACE-maintained navigation infrastructure. This literature review documents and summarizes those factors considered in establishing feasibility and long-term effectiveness of the approach as well as the applicable engineering tools employed and constraints encountered.
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