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Cremon, Cassiano; UNEMAT; Rosa Júnior, Edgard Jardim; UFMS; Serafim, Milson Evaldo; UFMS; Ono, Fábio Benedito; UFLA. |
O objetivo deste trabalho é caracterizar micromorfometricamente os agregados de um Latossolo submetido a diferentes formas de manejo do solo. O trabalho desenvolveu-se em um LATOSSOLO VERMELHO Distroférrico, de Dourados, Mato Grosso do Sul. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições e os tratamentos foram arranjados em parcelas sub-subdivididas. Os tratamentos consistiram de dois sistemas de manejo (convencional e plantio direto), duas doses de gesso (zero e 2 t ha-1) e a utilização de duas culturas de verão (soja e milho). Os agregados foram coletados, nas profundidades de 0 a 10 e 10 a 20 cm, utilizando-se, nos procedimentos experimentais, os retidos no intervalo de diâmetro de 9,52 e 4,76 mm, após... |
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Palavras-chave: 5.02.01.07-7 Solos Florestais plantio direto; Imagens digitais; Agregados. no-tillage; Digital images; Aggregates. |
Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/6640 |
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Lunven, Michel; Gentien, Patrick. |
Measurements made using an in situ particle-sizer (PSA) were compared to those of an optical backscatter sensor (OBS) in a macrotidal estuary. Both estimate the total volume of particles. After comparison with dry weight of suspended matter sampled in the study area, the different measurements were converted into dry weight. In three different kinetic energy regimes, times series were coherent for most of the observations. Discrepancies of suspended sediment concentrations estimated by both sensors appeared under specific hydrodynamic conditions: they were related to occurrences of definite particle populations. Overestimations and underestimations of measurements by the instruments depend on the optical principles of the sensors (backscatter and... |
Tipo: Text |
Palavras-chave: Particle size; Suspended particulate matter; Aggregates; Taille de particule; Matières en suspension; Agrégats. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-521.pdf |
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Long, Marc; Paul-pont, Ika; Hegaret, Helene; Moriceau, Brivaela; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe. |
To understand the fate and impacts of microplastics (MP) in the marine ecosystems, it is essential to investigate their interactions with phytoplankton as these may affect MP bioavailability to marine organisms as well as their fate in the water column. However, the behaviour of MP with marine phytoplanktonic cells remains little studied and thus unpredictable. The present study assessed the potential for phytoplankton cells to form hetero-aggregates with small micro-polystyrene (micro-PS) particles depending on microalgal species and physiological status. A prymnesiophycea, Tisochrysis lutea, a dinoflagellate, Heterocapsa triquetra, and a diatom, Chaetoceros neogracile, were exposed to micro-PS (2 μm diameter; 3.96 μg L−1) during their growth culture... |
Tipo: Text |
Palavras-chave: Polystyrene; Microplastic; Aggregates; Microalgae; Marine; Phytoplankton. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00389/50016/50735.pdf |
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Wernstedt, Kris; Cummings, Amy Mcabee. |
The patchwork of government influences that shape the protection and management of construction mineral resources--sand, gravel, and crushed stone--includes statutes, regulations, guidance documents, and court decisions at the federal, state, and local level. Across the Washington-Baltimore metropolitan area, both these influences and the experiences that the counties have had in managing construction mineral resources range widely. Our principal objective in this study is to discuss the mechanisms that counties use to manage such resources; the level and source of concern that local residents have with respect to construction mineral extraction operations; officials' perceptions about trends in the supply and demand for mineral resources; and the level of... |
Tipo: Working or Discussion Paper |
Palavras-chave: Construction minerals; Aggregates; Land use planning; Baltimore-Washington; Land Economics/Use; Q24; Q38; R52. |
Ano: 1999 |
URL: http://purl.umn.edu/10731 |
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