Ni Fe
Mostrando 1-12 de 960 artigos, teses e dissertações.
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1. Biphasic 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 nanopowders by in situ sol-gel synthesis
Abstract Nanopowders of the 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 (x=0, 0.25, 0.5, 0.75, and 1) were synthesized by the in situ sol-gel method using poly(acrylic acid) (PAA1800) as a chelating agent. The synthesis developed using PAA1800 ensured the simultaneous crystallization of two phases. The results provided a reliable method for producing biphasic nanopowders i
Cerâmica. Publicado em: 2022
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2. Boosting the Photocurrent of the WO3/BiVO4 Heterojunction by Photoelectrodeposition of the Oxy-Hydroxide-Phosphates Based on Co, Fe, or Ni
Here we investigated the photoelectrodeposition of oxygen-evolving catalysts (OECs) based on oxy-hydroxides-phosphates of Co, Fe, or Ni (CoPi, FePi, and NiPi) on the WO3/BiVO4 heterojunction and their activity in water oxidation. The OECs were deposited by cycles of (i) open-circuit potential (OCP) and (ii) applying a potential positive enough to oxidize the
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. FATORES DE EMISSÃO E DE ENRIQUECIMENTO DA CROSTA PARA ELEMENTOS TRAÇO (MP2,5) EMITIDOS PELA FROTA VEICULAR NA REGIÃO METROPOLITANA DE SÃO PAULO, BRASIL
Air pollution can cause several negative impacts on health and the environment. In large urban centers, this pollution is directly related to anthropogenic activities, mainly activities in the transportation sector. This study analyzed data on black carbon, fine particulate material (PM2.5) and its main trace elements from automotive vehicles (S, P, K, V, Cr
Química Nova. Publicado em: 2022
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4. Processamento de catalisadores gastos de unidade de hidrodessulfurização profunda (ultra-deep HDS)
PROCESSING OF SPENT ULTRA-DEEP HYDRODESULFURIZATION CATALYSTS. This work discusses the recycling of spent NiMo/Al2O3 catalysts from ultra-deep hydrodesulfurization (HDS) units. They contain a refractory coke and fouling elements from the processed feedstocks. Samples were preoxidized (600 ºC) for 12 h using a very slow heating rate to eliminate coke and vol
Química Nova. Publicado em: 2022
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5. Ferrimagnetic to paramagnetic transition and dielectric relaxation in Ni1-xZnxFe2O4 ferrites
Abstract The spinel ferrite system Ni1-xZnxFe2O4 (x=0-0.7, Δx=0.1) was prepared by wet chemical co-precipitation method using sulfates of respective metal ions. The electrical resistivity and dielectric properties of the prepared samples have been studied as a function of temperature, frequency, and Zn content (x). The DC resistivity (ϱ) was measured in th
Cerâmica. Publicado em: 2021-06
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6. Avaliação da concentração e composição inorgânica do material particulado coletado no estado do Rio de Janeiro
Cities urbanization and modernization increase emission sources, contributing to particulate matter (PM) composition heterogeneity and enhance the risk to human health and environment. This paper intends to survey the studies on particulate matter carried out in the state of Rio de Janeiro. The sampling of PM is generally made using Hi-Vol samplers to collec
Quím. Nova. Publicado em: 2021-06
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7. EFEITO DO HG2+ E DOS ÍONS CU2+, FE2+, NI2+, SN2+ E ZN2+ NA ESTABILIDADE DE NANOPARTÍCULAS DE PRATA: UMA PRÁTICA INTERDISCIPLINAR DE NANOTECNOLOGIA EXPERIMENTAL
The growing predominance of nanoscience and nanotechnology makes it increasingly important that these topics become an integral part of all scientific education. For this reason, in the present work, an interdisciplinary experiment of nanotechnology is introduced. As silver nanoparticles (AgNPs) are the most applied nanomaterial in consumer products, the cur
Quím. Nova. Publicado em: 2021-04
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8. Spatial Distribution and Pollution Assessment of Trace Elements Pb, Cu, Ni, Fe and As in the Surficial Water of Staring Bay, Indonesia
Staring Bay has long been used by the local community for fisheries and fishing activities; however, the rapid population growth and industrial activities around the bay in recent years are predicted to contribute significantly to the increase of waste entering the bay. This particular study was aimed to provide baseline levels of trace elements Pb, Cu, Ni,
J. Braz. Chem. Soc.. Publicado em: 2021-02
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9. Uma revisão sobre: tratamento biológico de drenagem de mina — cenário atualizado, perspectivas e recomendações de futuros trabalhos
RESUMO Rochas contendo sulfetos metálicos podem ser oxidadas em um processo catalisado por procariotos quimiolitoautotróficos ou Fe3+. A atividade mineradora acelera esse processo ao gerar resíduos contendo sulfetos metálicos com grande superfície de contato. O lixiviado resultante, conhecido como drenagem de mina (DM), é rico em sulfato, íons hidrog�
Eng. Sanit. Ambient.. Publicado em: 2021-02
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10. Mineral Nutrients and Plant-Fungal Interaction in Cocoa Trees (Theobroma cacao L.)
An infection of the fungus Moniliophthora perniciosa in cocoa trees reduces productivity of the plant. In this study, the concentrations of mineral nutrients in healthy leaves and in leaves of vegetative broom of the cocoa plant were determined, and the relationship between the disease and the nutritional composition of the leaves was assessed. The samples w
J. Braz. Chem. Soc.. Publicado em: 2021-02
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11. An Efficient and Recyclable Sn-Based Phosphotungstic Acid with Tunable Brønsted/Lewis Acidity for Selective Oxidation of Benzyl Alcohol
A series of metal ion (M = Sn2+, Fe3+, Ni2+, Co2+, Ag+, Cu2+) exchanged tungstophosphoric acid (H3PW12O40; TPA) catalysts with tunable Brønsted/Lewis acidity were synthesized and exploited for the oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using hydrogen peroxide (H2O2) as oxidant. The structure of these M-TPA composite salts was also characte
J. Braz. Chem. Soc.. Publicado em: 2021-01
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12. Nutritional quality and sensory attributes of date palm spathes beverage supplemented with pollen grains
Abstract The aim of this study was to fortify date palm spathes beverage with pollen grains. The nutritional quality and sensory attributes of the developed products were evaluated. The results showed that pollen grains significantly (P < 0.05) influenced the nutritional and sensory qualities of date palm spathe beverages. With minor exceptions, fortificatio
Food Sci. Technol. Publicado em: 2020-12