Rare Earth
Mostrando 13-24 de 213 artigos, teses e dissertações.
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13. Geochemistry of the Northern Paraná Continental Flood Basalt (PCFB) Province: implications for regional chemostratigraphy
ABSTRACT: The Paraná Continental Flood Basalt (PCFB) province is one of the largest igneous provinces on Earth, but little is known about the architecture and geochemical characteristics of the lava flows. In this context, a set of borehole samples arranged in an NEE-SWW profile - more than 600 km long - located in the northern PCFB was used to define its c
Braz. J. Geol.. Publicado em: 2018-06
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14. Green Processing of Strategic Elements Based on Magnetic Nanohydrometallurgy
Magnetic nanohydrometallurgy (NHM) is a new process based on engineered superparamagnetic nanoparticles capable of performing as complexing agents for extracting and recovering strategic metals from mineral sources and urban wastes, as well as for removing hazardous elements from contaminated water. Its principles and application are reviewed in this paper.
J. Braz. Chem. Soc.. Publicado em: 2018-05
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15. 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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16. Characterization of CBD-CdS Doped with Some Rare Earths III (Eu3+,Ce3+) as Function of Synthesis Time
Rare earths (Europium, cerium)-doped CdS nanofilms are prepared using the growth technique chemical bath deposition (CBD) at the reservoir temperature of 70±2°C varying the synthesis time in a wide range. For the rare earths doped CdS nanofilms the synthesis time was ranged from 80 to 135 min. The rare earths molar concentration was in the range 0.0≤x≤
Mat. Res.. Publicado em: 01/02/2018
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17. Ab initio LSDA+U Study of Optical Properties of RVO4 (R = Eu, Ho, Lu) Compounds
A first principles investigation at the pressure 7 GPa of the optical properties of RVO4 (R= Eu, Ho, Lu) orthovanadates in the framework of the density functional theory (DFT) using the linearized-augmented plane-wave method is reported in order to predict new optical materials for continuous-wave lasers. The electronic structure of all orthovanadates is stu
Mat. Res.. Publicado em: 22/01/2018
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18. Rare Earth-Indomethacinate Complexes with Heterocyclic Ligands: Synthesis and Photoluminescence Properties
In this work, synthesis, characterization and photophysical properties of trivalent rare earth complexes with a nonsteroidal anti-inflammatory drug [the indomethacinate (indo), presenting formulas RE(indo)3(H2O)x (x = 3, for Eu3+ and Gd+3, and x = 4 for Tb+3), RE(indo)3(bipy) and RE(indo)3(phen) (bipy: 2,2'-bipyridine, and phen: 1,10-phenanthroline)] were in
J. Braz. Chem. Soc.. Publicado em: 2017-12
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19. Magnetic topology with axial flux concentration: a technique to improve permanent-magnet motor performance
Abstract This article presents a different topology for the magnetic circuit of permanent-magnet motors, using the concept of Axial Flux Concentration. By means of longitudinal extension of the rotor length beyond the stator core, a substantial increase in the flux per pole is enabled, improving the general performance of the machine. Even in low cost motors
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-12
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20. Determination of Rare Earth Elements in Some Flower Herb Teas and their Infusions
The aim of this study was to determine the sixteen rare earth elements (REEs) in twelve types of popular flower herb teas and their infusions consumed in China. Microwave-assisted acid digestion was used for all of the samples, and the contents of these elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of R
J. Braz. Chem. Soc.. Publicado em: 2017-10
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21. Effect of La Doping on the Crystal Structure, Electric, Magnetic and Morphologic Properties of the BSCCO System
Studies of the doping process can provide a better understanding of the superconducting mechanisms in cuprous oxide materials. In this work, we studied the doping effects on the crystal structure, electric, morphologic and magnetic properties of the BSCCO system with the nominal composition Bi1.6Pb0.4Sr(2-x)RExCa2Cu3O(10-δ). Here, the rare earth element (RE
Mat. Res.. Publicado em: 03/08/2017
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22. Luminescent and Magnetic Properties of Fe3O4@SiO2:phen:Eu3+
Magnetite was doped with rare earth ions (europium) to produce core-shell materials with both magnetic and luminescent properties, i.e., a magnetic Fe3O4 oxide core and a SiO2:phen:Eu3+ shell. The resulting material was analyzed by X-ray powder diffraction and transmission electron microscopy, and subjected to magnetic and luminescence emission measurements.
Mat. Res.. Publicado em: 24/06/2017
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23. Rare Earth Element Concentrations in Brazilian Benchmark Soils
ABSTRACT: Studies regarding background concentrations of rare earth elements (REEs) are scarce and have mainly focused on a limited number of soil types from the northern hemisphere. The aim of this study was to determine REE concentrations in thirty-five benchmark soils of Brazil. Composite soil samples were taken from areas under native vegetation or with
Rev. Bras. Ciênc. Solo. Publicado em: 15/12/2016
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24. Simultaneous Determination of Rare Earth Elements by ICP OES After On-Line Enrichment Using Multi-Walled Carbon Nanotubes Coated Cellulose Acetate Membrane
This study investigates application of multi-walled carbon nanotubes coated cellulose acetate membrane for on-line extraction and preconcentration of some rare earth elements (Y, La, Ce, Nd, Sm, Gd and Dy) prior to their determination by inductively coupled plasma optical emission spectrometry. Sample solutions containing rare earth elements (pH: 6.0) and l-
J. Braz. Chem. Soc.. Publicado em: 2016-12