Calcite
Mostrando 13-24 de 99 artigos, teses e dissertações.
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13. Análisis arqueométrico de pigmentos del sitio arqueológico Tambo Colorado por difracción de rayos X sincrotrón
ABSTRACT Despite the exceptional architecture and polychromy of archaeological site of Tambo Colorado, there has been no conservation work or in the architectural structures of raw earth, nor on the surfaces. These jobs require a proper understanding of the state of conservation of the site architecture and the analysis of the materials used. With this purpo
Matéria (Rio J.). Publicado em: 20/05/2019
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14. Microfacies and diagenetic evolution of the limestones of the upper part of the Crato Formation, Araripe Basin, northeastern Brazil
Abstract This paper presents the results of a petrographic and diagenetic study of the laminated limestones of the upper part of the Aptian to Albian Crato Formation, northeast of Brazil. The applied techniques were optical microscopy, cathodoluminescence and scanning electron microscopy (SEM) coupled to a wavelength-dispersive spectrometer (WDS). Petrograph
Braz. J. Geol.. Publicado em: 08/04/2019
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15. Biodegradation of Poly (3-hydroxybutyrate) /Eggshellsystems
In this work, biocomposites of poly (3-hydroxybutyrate) (PHB) / calcium carbonate from Rhea Americana eggshells were prepared and the effects of the addition of the inorganic filler in the polymeric matrix were assessed. The residue (powder) of the eggshell calcined at 400 ºC or in natura was inserted into a PHB solution for preparation of films via casting
Mat. Res.. Publicado em: 21/05/2018
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16. Physical and Mechanical Characterization of Artificial Stone with Marble Calcite Waste and Epoxy Resin
The incorporation of calcite marble waste in epoxy resin for the production of artificial stone can represent a technical-economical method and environmentally viable, reducing the amount of discarded residue in the environment, and adding economic value to marble waste and enabling the generation of jobs. The production of natural stone in Brazil recorded a
Mat. Res.. Publicado em: 07/12/2017
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17. Effect of dissolution kinetics on flotation response of calcite with oleate
Abstract Phosphate flotation performance can be influenced by the dissolution kinetics of the minerals that compose the ore. The purpose of this work was to investigate the effect of dissolution kinetics on flotation response with oleate (collector) of calcites from different origins and genesis. The calcite samples were first purified and characterized by x
Braz. J. Chem. Eng.. Publicado em: 2017-10
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18. Synthesis of Submicrometer Calcium Carbonate Particles from Inorganic Salts Using Linear Polymers as Crystallization Modifiers
In this study, we report the synthesis of submicrometer calcium carbonate particles using the simplest approach of mixing solutions of calcium chloride and ammonium carbonate inorganic precursors in the presence of crystallization modifiers. Instead of the typical crystallization of CaCO3 into large calcite crystals with rhombohedral morphology, very small u
J. Braz. Chem. Soc.. Publicado em: 2017-04
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19. Carbon regeneration in the Cariaco Basin, Venezuela
Resumo A regeneração de carbono na coluna de água da Bacia de Cariaco (Venezuela) foi investigada utilizando um modelo de regressão de alcalinidade total (TA) e a concentração de carbono inorgânico total (TCO2). Produtividade primária (PP) foi determinada a partir da fracção de carbono inorgânico assimilável pelo fitoplâncton e a variação da i
Braz. j. oceanogr.. Publicado em: 2017-03
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20. Genesis and Classification of Soils Containing Carbonate on the Apodi Plateau, Brazil
ABSTRACT Information is scarce on the genesis and classification of soils derived from calcareous rocks in the Northeastern region of Brazil. This study describes the morphological, physical, chemical, mineralogical, and micromorphological properties of four soil profiles (P1-P4) located in the Apodi Plateau. A pedogenesis hypothesis and soil classification,
Rev. Bras. Ciênc. Solo. Publicado em: 31/05/2016
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21. Biomineralization processes of calcite induced by bacteria isolated from marine sediments
Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these speci
Braz. J. Microbiol.. Publicado em: 2015-06
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22. Polymorphism of CaCO3 and microstructure of the shell of a Brazilian invasive mollusc (Limnoperna fortunei)
Applying the theories of Materials Science and Engineering to describe the composition and hierarchy of microstructures that comprise biological systems could help the search for new materials and results in a deeper insight into evolutionary processes. The layered microstructure that makes up the freshwater bivalve Limnoperna fortunei shell, an invasive spe
Mat. Res.. Publicado em: 15/04/2014
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23. Caracterização e classificação quanto ao risco ambiental do estéril da mina de cromita do município de Andorinha, Bahia
The mineral waste studied was host rock from a chromite mine located in Andorinha/Bahia, extracted and stockpiled in yards without specific application. Host rock was submitted to chemical analysis, XRD, SEM-EDS, IR and TGA and classified according to ABNT standards for solid waste classification. Analyses confirmed that this host rock, classified as ultraba
Quím. Nova. Publicado em: 2012
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24. Effect of culture medium on biocalcification by Pseudomonas Putida, Lysinibacillus Sphaericus and Bacillus Subtilis
The objective of this study is to investigate the efficiency of calcium carbonate bioprecipitation by Lysinibacillus sphaericus, Bacillus subtilis and Pseudomonas putida, obtained from the Coleção de Culturas do Instituto Nacional de Controle de Qualidade em Saúde (INCQS), as a first step in determining their potential to protect building materials agains
Brazilian Journal of Microbiology. Publicado em: 2011-06