Clay
Mostrando 13-24 de 1165 artigos, teses e dissertações.
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13. Organophilic clays and their application in atrazine adsorption
Abstract Atrazine’s adsorptive capabilities make the use of clays practical and effective. Three types of organophilic clays modified by cationic surfactants with the ability of one of these clays to adsorb atrazine in an aqueous medium are discussed in this work. The modification in clays was done with the surfactants cetyltrimethylammonium bromide, cetyl
Cerâmica. Publicado em: 2021-06
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14. Expansibility of vermiculite (Santa Luzia, Brazil) irradiated with microwave
Abstract The effect of microwave heating on the expansion of vermiculite was studied at a level of 700 W for 4 min exposure time and compared with raw vermiculite. In this study, the characterization of vermiculite from a mine in the northeast region of Brazil was performed using thermogravimetry, N2-adsorption, cation exchange capacity, X-ray powder diffrac
Cerâmica. Publicado em: 2021-06
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15. Purification of raw palygorskite: a comparative study involving different processes and dispersing agents
Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes
Cerâmica. Publicado em: 2021-06
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16. Microbial activity and studies on excavated megalithic micaceous potsherds from Peninsular India
Abstract The abundantly available mica flakes were added in raw materials to manufacture pottery in Central Peninsular India during the early Iron Age (700-300 BCE) for storage and glittering. The micaceous potsherds from the excavated megalithic site of Nagpur were studied for their composition, manufacturing techniques, microstructural features, microbial
Cerâmica. Publicado em: 2021-06
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17. Study of the interaction of concrete walls with the foundation structure
Abstract This article presents a study of the factors that influence the mechanism of soil-structure interaction with a pilot building having concrete walls and their impact on their performance. To illustrate the studies carried out, a numerical modeling of a four-floor concrete wall pilot building was performed, subjected to vertical actions, supported by
REM, Int. Eng. J.. Publicado em: 2021-06
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18. Brazilian Mineral Clays: Classification, Acid Activation and Application as Catalysts for Methyl Esterification Reactions
In this study, three raw Brazilian clays from João Pessoa, Paraíba State (Aço AP, AVL and Verde Lodo) were characterized before and after purification and acid activation. Several instrumental techniques were used, and the raw clays were classified as dioctahedral smectites with different compositions, where the AVL sample had the highest content of montm
J. Braz. Chem. Soc.. Publicado em: 2021-01
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19. BIONANOCOMPÓSITOS POLIMÉRICOS À BASE DE MONTMORILLONITA – MATERIAIS DE INTERESSE CONTÍNUO
Polymeric bionanocomposites are versatile materials that have many practical applications. The wide use of these materials is mainly due to their structure and properties, which combine at nanometric scale, the functionality of biopolymers with the excellent stability of inorganic solids, such as the clay minerals family. Montmorillonite is the most widely e
Quím. Nova. Publicado em: 2020-12
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20. Forecasting bearing capacity performance with semi-empirical and theoretical methods applied to precast concrete piles founded on sandy clay in the region of Uberlândia-MG, Brazil
Abstract This article presents a study on the performance of semi-empirical methods based on the Standard Penetration Test (SPT) for the prediction of bearing capacity already disseminated in the practice of Brazilian Foundation Engineering (Aoki and Velloso, 1975; Décourt and Quaresma, 1978, 1996; Teixeira,1996), together with the recent method proposed by
REM, Int. Eng. J.. Publicado em: 2020-12
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21. Collusion: How Central Bankers Rigged the World
Abstract This article presents a study on the performance of semi-empirical methods based on the Standard Penetration Test (SPT) for the prediction of bearing capacity already disseminated in the practice of Brazilian Foundation Engineering (Aoki and Velloso, 1975; Décourt and Quaresma, 1978, 1996; Teixeira,1996), together with the recent method proposed by
Contexto int.. Publicado em: 2020-12
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22. Maximization of the use of casting sand residue in the production of fired ceramic bricks
Abstract In this study, a red ceramic was developed with the addition of sand residue from deburring and finishing processing of cast iron molds, replacing a variable fraction of the clay. The formulated masses were shaped by pressing and firing at different temperatures (850, 900 and 1000 ºC) at a heating rate of 180 ºC/h and 2-hour level. The bodies were
REM, Int. Eng. J.. Publicado em: 2020-09
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23. Mineralogical characterization of copper lateritic ore from the Furnas deposit - Carajás, Brazil
Abstract Furnas is a small and not well-known copper sulfide deposit in the northern Carajás mineral province (Pará State, Brazil). Mineralogical and geochemical studies were performed on three weathered samples in order to verify the presence of copper in the lateritic minerals. According to these Cu-bearing minerals (malachite, e.g.), the weathered ore c
REM, Int. Eng. J.. Publicado em: 2020-09
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24. Large strain consolidation analyses of fine tailings disposal in mining pits
Abstract Herein, three-dimensional analyses of large strain consolidation applied to tail ings disposal in mining pits is studied. The main goal is to estimate filling time and, ac cordingly, the capacity of the pit. Other useful results, such as dry density profiles and water pore pressure generation are also obtained. Two different slimes from the iron or
REM, Int. Eng. J.. Publicado em: 2020-09