Cerium
Mostrando 13-24 de 100 artigos, teses e dissertações.
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13. Synthesis and Characterization of Cerium Molybdate Semiconductor Nanoparticles
Cerium molybdate semiconductive nanoparticles were synthesized by the EDTA-citrate combined complexation method. Gel thermal degradation behavior, phase formation, morphology, composition and band gap of cerium molybdate powders were characterized by TG/DSC, XRD, SEM/EDS and DRS analysis, respectively. The nanoparticles were synthesized by fixing the pH of t
Mat. Res.. Publicado em: 19/10/2017
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14. Corrosion Mechanism Suggested Based on Electrochemical Analysis and SVET for Uncoated Tinplate and Post Coated With a Hybrid Film
The tinplate, used in the packaging sector and formed from a metal substrate, comprises a steel base which has undergone a surface treatment to produce a thin layer of FeSn2, a tin layer and an oxide tin layer. Currently, packaging using surface treatment is based on the use of chromates because these metals provide an excellent corrosion resistance. Nontoxi
Mat. Res.. Publicado em: 09/10/2017
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15. The Production of UV Absorber Amorphous Cerium Sulfide Thin Film
This study investigates the production of cerium sulfide (CeSx) amorphous thin films on substrates (commercial glass) by chemical bath deposition at different pH levels. The transmittance, absorption, optical band gap and refractive index of the films are measured by UV/VIS Spectrum. According to XRD analysis, the films show amorphous structure in the baths
Mat. Res.. Publicado em: 27/07/2017
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16. Preparation and Anti-Corrosive Properties of Cerium Oxide Conversion Coatings on Steel X52
In this study, cerium-based conversion coating was deposited on steel X52 by dip immersion method. Cerium oxide/hydroxide is an environmentally friendly conversion coating. The effects of immersion times and immersion temperatures on corrosion properties of cerium conversion coating on steel X52 were studied. Its corrosion resistance in 3.5 wt.% NaCl solutio
Mat. Res.. Publicado em: 09/02/2017
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17. SYNTHESIS OF CUMENE BY TRANSALKYLATION OVER MODIFIED BETA ZEOLITE: A KINETIC STUDY
Abstract In the present study, transalkylation of 1,4-diispropylbenzene (DIPB) with benzene in the presence of modified beta zeolite was performed to produce cumene in a fixed bed reactor. Beta zeolite was exchanged with cerium in order to modify its catalytic activity. Activity of the modified catalyst was evaluated in the range of temperature 493K-593K, sp
Braz. J. Chem. Eng.. Publicado em: 2016-12
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18. CERIUM INCORPORATED INTO A MESOPOROUS MOLECULAR SIEVE (MCM-41)
Abstract The synthesis and characterization of a mesoporous molecular sieve (MCM-41) was studied due to its high surface area and large pore volume and to target potential applications in adsorption and catalysis. Rare earth elements have special chemical properties and are efficient promoters for supports. In this study, a mesoporous molecular sieve that in
Braz. J. Chem. Eng.. Publicado em: 2016-09
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19. Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles
Cerium oxide (CeO2) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium o
Mat. Res.. Publicado em: 15/03/2016
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20. Determination of Aspirin Using Chemiluminescence System of Tris(1,10 phenanthroline)Ruthenium(II)-Cerium(IV)
A new chemiluminescence (CL) method has been proposed for the simple determination of aspirin (acetylsalicylic acid, ASA). The method is based on the enhancement effect of ASA in the CL reaction of tris(1,10 phenanthroline)ruthenium(II), Ru(phen)32+, with cerium(IV) (CeIV) in acidic medium. Under optimum conditions, the CL intensity was proportional to the c
J. Braz. Chem. Soc.. Publicado em: 2016-03
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21. Separation of rare earths by solvent extraction using DEHPA
Abstract This paper presents results or the analysis of process variables for separating light REE and heavy REE, in chloride media, by solvent extraction. DEHPAIsoparaffin was used as the extraction system and the liquor was produced in the laboratory by dissolving REE oxides in HCl to simulate leaching liquor originating from monazitic ores after cerium re
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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22. Effect of Processing on Microstructure and Corrosion Mitigating Properties of Hydrotalcite Coatings on AA 6061 Alloy
Pitting corrosion of the aluminium cladding of spent nuclear fuels stored in light water pools has been observed. To prevent this, coating of the Al cladding with hydrotalcite (HTC) was proposed. This paper presents the effect of chemical bath and processing parameters on microstructure and corrosion behavior of HTC coatings on alloy AA 6061 specimens. The H
Mat. Res.. Publicado em: 03/11/2015
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23. New Sol-gel Formulations to Increase the Barrier Effect of a Protective Coating Against the Corrosion and Wear of Galvanized Steel
This study proposes a new pretreatment method that uses alkoxide precursors with a plasticizing agent; the purpose of this study is to improve the electrochemical and mechanical properties of a galvanized steel surface. Galvanized steel was covered with a hybrid film obtained from a sol that consisted of two alkoxide precursors, 3 - (trimethoxysilylpropyl) m
Mat. Res.. Publicado em: 2015-02
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24. Catalytic oxidation of volatile organic compounds (n-hexane, benzene, toluene, o-xylene) promoted by cobalt catalysts supported on γ-Al2O3-CeO2
Cobalt catalysts supported on γ-alumina, ceria and γ-alumina-ceria, with 10 or 20%wt of cobalt load, prepared by the wet impregnation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission transmission electron microscopy (FETEM), N2 adsorption-desorption isotherms (BET/BJH methods), energy-dispersive X-ray
Braz. J. Chem. Eng.. Publicado em: 2014-09