Magnetite
Mostrando 13-24 de 180 artigos, teses e dissertações.
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13. Iron oxide/titania composites for radar absorbing material (RAM) applications
Resumo Compósitos de óxido de ferro/titânia foram sintetizados pelo método de precipitação. A quantidade de óxido de ferro foi variada nos compósitos. Fase única (anatásio) foi obtida para a fração em massa de 0-20% e três fases (anatásio, magnetita e hematita) foram encontradas para as frações de 30% e 40% de óxido de ferro. O tamanho de cr
Cerâmica. Publicado em: 15/08/2019
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14. MONITORAMENTO DA COMPOSIÇÃO EM ÉSTERES DO BIODIESEL DO ÓLEO DE AMÊNDOA DA MACAÚBA (Acrocomia aculeata (Jacq.) Lodd. ex Mart.) EM CONTATO DIRETO COM O AÇO CARBONO E O AÇO CARBONO GALVANIZADO
The oil from the macaúba (Acrocomia aculeata) fruit, a native palm in Brazil, has a real potential for the industrial production of biodiesel. This report describes an experimental work devoted to monitor the chemical behavior of the fatty acid methyl esters from oil of the macaúba fruit kernel and the leaching of metal elements into the biodiesel put in c
Quím. Nova. Publicado em: 27/05/2019
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15. Fe3O4-TiO2 and Fe3O4-SiO2 Core-shell Powders Synthesized from Industrially Processed Magnetite (Fe3O4) Microparticles
The interest for core-shells has been increased in the recent years due to their improved and modifiable properties. In this work, Fe3O4-TiO2 and Fe3O4-SiO2 core-shells were successfully synthesized from an industrially produced magnetite-rich powder with micro- and nanometric particle sizes, superparamagnetic behavior and saturation magnetization of 49 emu/
Mat. Res.. Publicado em: 09/05/2019
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16. The Cristalino IOCG deposit: an example of multi-stage events of hydrothermal alteration and copper mineralization
Abstract The Cristalino deposit is located 40 km east of Sossego mine, Carajás. The orebody lies along a NW-SE-striking shear zone and is mainly hosted by the Neoarchean bi-modal volcanics of the Grão Pará Group. Field work and petrographic data seconded by SEM-EDS analysis allowed recognizing an early sodic metasomatism that was followed by calcic-ferric
Braz. J. Geol.. Publicado em: 15/04/2019
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17. Structural, Morphological and Magnetic Properties of FeCo-(Fe,Co)3O4 Nanocomposite Synthesized by Proteic Sol-Gel Method Using a Rotary Oven
FeCo nanoparticles coated with (Fe,Co)3O4 (magnetite doped with cobalt) were synthesized by the proteic sol-gel chemical route. The synthesized materials were characterized by Thermogravimetry (TG), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), vibrating-sample magnetometer (VSM) and Mössbauer spectrosc
Mat. Res.. Publicado em: 18/03/2019
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18. Esfuerzo de corte en Interfaces Fe/Fe3O4
Abstract The mechanical stability of oxides formed on metallic alloys is a key concern in the determination of component susceptibility to the medium in contact and the applicability of the alloy to high temperatures and other extreme conditions. In this context, the energy of adhesion is a key parameter. Density functional Theory (DFT) and other atomistic m
Matéria (Rio J.). Publicado em: 19/07/2018
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19. Enhancing the Supercapacitive and Superparamagnetic Performances of Iron Oxide Nanoparticles through Yttrium Cations Electro-chemical Doping
A one-pot electrosynthesis platform is reported for fabrication of Y3+ doped iron oxide nanoparticles (Y-IONPs). In this procedure, Y-IONPs are electro-deposited from an additive-free aqueous solution of iron(III) nitrate, iron(II) chloride and yttrium chloride. The analysis data provided by X-ray diffraction (XRD), field emission electron microscopy (FE-SEM
Mat. Res.. Publicado em: 10/07/2018
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20. Carbothermic reduction of Electric Arc Furnace Dust via thermogravimetry
Abstract Electric Arc Furnace Dust (EAFD) is a solid waste originated from electric steelmaking furnaces. Currently, according to some authors, there is an estimated generation of 15 to 25 kg of dust per ton of steel produced. The formation of the dust is related to the following steps of the process: furnace charge, metal volatilization, iron vaporization u
REM, Int. Eng. J.. Publicado em: 2018-07
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21. Amorphization of Graphite Flakes in Gray Cast Iron Under Tribological Load
A gray cast iron disc, which had been submitted to a heavy duty automotive brake test, was examined with energy filtered transmission electron microscopy. A graphite flake in a convenient angular position showed the shear interaction of graphite layers with the iron matrix in nano-scale resolution. Atomic layers of graphite were wedged into the ferritic bulk
Mat. Res.. Publicado em: 28/05/2018
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22. Evaluation of internal corrosion in a Brazilian iron ore slurry pipeline based on the characterization of scales and tubercles
Abstract The transport capacity of long-distance slurry pumping systems is directly related to the roughness of the pipe. In this context, corrosion plays an important role, especially when dealing with old pipes. Chemical, mineralogical and microstructural analyses were performed on materials removed from the internal surface of an iron ore slurry pipeline
REM, Int. Eng. J.. Publicado em: 2018-04
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23. Geology, geochemistry and petrology of basalts from Paraná Continental Magmatic Province in the Araguari, Uberlândia, Uberaba and Sacramento regions, Minas Gerais state, Brazil
Abstract: This study covers the region between the cities of Sacramento and Araguari/Uberlândia (Minas Gerais State, Brazil), where basalt flows from the Paraná Continental Magmatic Province outcrop. The investigated rocks present tholeiitic signature, with high titanium content, and are classified as Pitanga magma-type. The preserved basalt thickness is b
Braz. J. Geol.. Publicado em: 22/02/2018
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24. Microstructural Assessment of Magnetite Nanoparticles (Fe3O4) Obtained by Chemical Precipitation Under Different Synthesis Conditions
Magnetite nanosized particles synthesis was achieved by two different routes. Assessment of microstructure was carried out aiming at comparing the outcome of synthesis parameters on the crystallinity, distribution of particle dimension and magnetic activity of nanosized particles precipitated in aqueous solution. Increasing of the nanoparticles crystallite s
Mat. Res.. Publicado em: 15/02/2018