Clay Minerals
Mostrando 13-24 de 135 artigos, teses e dissertações.
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13. Phosphate Adsorption by Montmorillonites Modified with Lanthanum/Iron and a Laboratory Test using Water from the Jacarepaguá Lagoon (RJ, Brazil)
Montmorillonites modified with lanthanum(III) and iron(III) were prepared from two commercial clays. These materials were characterized by powder X-ray diffraction analysis, X-ray fluorescence, infrared spectroscopy, N2 adsorption, and scanning electron microscopy. The incorporation of lanthanum(III) and iron(III) varied from 0 to 4.00%. The amount of these
J. Braz. Chem. Soc.. Publicado em: 2019-03
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14. Genesis and Classification of Nitisols from Volcano-Sedimentary Lithology in Northeastern Brazil
ABSTRACT On the southern coast of Pernambuco State (PE), Brazil, lithotypes of the Cabo Basin (volcanic and sedimentary rocks), in association with the relief, allow the determination of the dynamics of the formation of Nitossolos Háplicos (Nitisols), including those with high levels of exchangeable aluminum. The objective of this study was to evaluate the
Rev. Bras. Ciênc. Solo. Publicado em: 14/02/2019
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15. Geochemical signatures and weathering rates in soils derived from different granites in contrasting climatic locations
ABSTRACT. We studied the mineralogical properties and chemical composition of different granites using energy dispersive X-ray spectroscopy coupled with scanning electron microscopy to understand the relationship between granite signatures and soil characteristics, including weathering patterns and soil fertility status. The discriminant analysis (DA) was ba
Acta Sci., Agron.. Publicado em: 17/12/2018
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16. Mineralogy, magnetic susceptibility and geochemistry of Fe-rich Oxisols developed from several parent materials
ABSTRACT: Fe-rich Oxisols on mafic rocks in Brazil generally have high magnetic susceptibility with high contents of some trace elements. These are taxonomically similar soils; however, differences in magnetic and geochemical properties may affect agricultural or environmental usability and subsequent management. This study investigated the pedogenesis of Fe
Sci. agric. (Piracicaba, Braz.). Publicado em: 2018-09
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17. Mineralogy and Concentration of Potentially Toxic Elements in Soils of the São Francisco Sedimentary Basin
ABSTRACT Lithological and geomorphological variations determine formation of soils with different mineralogical constitutions and can influence the distribution of potentially toxic elements (PTE). The aim of this study was to determine the contents of PTE and mineralogical assemblages along soil profiles of different classes and parent materials and to inve
Rev. Bras. Ciênc. Solo. Publicado em: 24/05/2018
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18. Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities
ABSTRACT: The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was
Sci. agric. (Piracicaba, Braz.). Publicado em: 2018-04
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19. Identification of Heavy Metals in Crystals of Sand and Silt Fractions of Soils by Scanning Electron Microscopy (SEM EDS/WD-EPMA)
ABSTRACT Studies of heavy metals are concentrate on clay fractions, but coarser fractions of the soil can constitute significant sources of structural forms of heavy metals. The aim of this study was to evaluate the occurrence of heavy metals in the structure of minerals of the sand and silt fractions of soils from three different parent materials (metamorph
Rev. Bras. Ciênc. Solo. Publicado em: 08/03/2018
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20. Clay Mineralogy of Basaltic Hillsides Soils in the Western State of Santa Catarina
ABSTRACT A commonly accepted concept holds that highly fertile, shallow soils are predominant in the Basaltic Hillsides of Santa Catarina State, in southern Brazil, but their agricultural use is restricted, either by excessive stoniness, low effective depth or steep slopes. Information about soil properties and distribution along the slopes in this region is
Rev. Bras. Ciênc. Solo. Publicado em: 22/02/2018
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21. Copper and zinc accumulation, fractionation and migration in vineyard soils from Santa Catarina State, Brazil
ABSTRACT The purpose of this study was to evaluate Cu and Zn migration and fractions in sandy soil of vineyards. In Urussanga (SC), Brazil, soil samples were collected from a 4-year-old and 15-yearold vineyard, and from a forested area. In the soils, the chemical characteristics of Cu and Zn were analyzed by the EDTA method, which determines the fraction ava
Bragantia. Publicado em: 18/12/2017
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22. Weathering of Rhyolites and Soil Formation in an Atlantic Forest Fragment in Northeastern Brazil
ABSTRACT Weathering and pedogenesis have been studied for a wide range of rocks and climates around the world. However, the eruption of rhyolitic magmas is a rare geological event, which leads to few studies associated with the rhyolite-soil-landscape relationship. In this context, this study evaluated the influence of rhyolite weathering on the properties o
Rev. Bras. Ciênc. Solo. Publicado em: 02/10/2017
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23. Mineralogy of the Clay Fraction and Chemical Properties of Soils Developed from Sedimentary Lithologies of Pirambóia, Sanga-the-Cabral and Guará Geological Formations in Southern Brazil
ABSTRACT Quali-quantitative and crystallographic characterizations of the different minerals of a soil are essential for the best evaluation of its genesis, degree of weathering, active pedogenetic processes, physical and chemical properties, and its potential reserve of mineral nutrients. This study presents the results of mineralogical investigations carri
Rev. Bras. Ciênc. Solo. Publicado em: 31/08/2017
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24. Clay Mineralogy of Brazilian Oxisols with Shrinkage Properties
ABSTRACT Shrinkage capacity (caráter retrátil in Portuguese) is a new diagnostic characteristic recently introduced in the Brazilian System of Soil Classification (SiBCS) to indicate shrink and swell properties observed in subtropical soils from highland plateaus in southern Brazil, specifically in Oxisols with brown colors. In soils located in road cuts e
Rev. Bras. Ciênc. Solo. Publicado em: 24/08/2017