Vanadium
Mostrando 1-12 de 168 artigos, teses e dissertações.
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1. Metal-Supported Niobium Catalysts Investigation for Conversion of Bio-Renewable Glycerol to Organic Compounds
The glycerol oxidative dehydration to organic compounds, especially acrolein and acrylic acid, was studied over vanadium, molybdenum, and cobalt oxides supported on niobium oxide and niobium phosphate catalysts. At 300 °C, the glycerol conversion was 100% over all catalysts tested, and acrolein was the main product observed, without significant deactivation
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Obtainment of a new metal matrix composite from the recycling of UNS S31803 duplex stainless steel by powder metallurgy
Abstract The purpose of circular economy is to maximize resources efficiency. With the increase in consumption of raw materials, energy and waste generation, recycling is necessary for environmental and industrial reasons. Thus, the powder metallurgy, together with mechanical milling, stands as a new method for scraps recycling. This study aimed to produce U
REM - International Engineering Journal. Publicado em: 2022
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3. 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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4. Monochromatic double coloring effect on V2O5 thin films deposited by electron beam
ABSTRACT Electrochromic material is a thin film technology that has a close relationship with environmental sustainability since they can control the light and heat that enter and leave a building. Vanadium oxide films are electrochemically active for lithium and electron co-intercalation, presenting low optical variation in the low energy visible light, whi
Matéria (Rio J.). Publicado em: 25/11/2019
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5. Analysis of the densification of a composite obtained by sintering process of aluminum bronze powders with different carbides
Abstract Aluminum bronze alloy is applied in environments that require materials of high mechanical resistance and wear, such as marine, oil & gas and aerospace ones. This study analyzes the densification of composites based on aluminum bronze with additions of the vanadium (VC) and niobium (NbC) carbides, and the influence of these carbides in the milling e
REM, Int. Eng. J.. Publicado em: 19/06/2019
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6. Oxidative Dehydration of Glycerol over Molybdenum- and Vanadium-Based Catalysts
Surplus of glycerol production from the biodiesel industry has led to the search for glycerol conversion routes, the most common of which are dehydration and oxidative dehydration. Vanadium and molybdenum oxides were supported on γ-Al2O3 and their properties were analyzed through several characterization techniques, showing that the acidity increases after
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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7. Commitment Between Roughness and Crystallite Size in the Vanadium Oxide Thin Film opto-electrochemical Properties
The V2O5 thin films has been widely studied because it has application as ionic host in electrochromic and lithium-ion batteries, two technologies that have an intimate connection with sustainability as substitutes for fossil energies and as agents for improving energy efficiency. In electrochromic technology, V2O5 is applied as a passive electrode due to it
Mat. Res.. Publicado em: 01/11/2018
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8. Efecto de la sustitución de V por Ti sobre las temperaturas de transformación de fase y el desajuste de red matriz/precipitado en la superaleación 76Fe-12Al-12V
ABSTRACT Fe-Al based alloys have a remarkable potential for high temperature structural applications, provided that the limitation of their low creep resistance is solved. Third element addition (Nb, Ti, Zr or Ta) has proven to per-form the task, at the expense of a low ductility. In previous works we have investigated ferritic alloys in the Fe-Al-V system w
Matéria (Rio J.). Publicado em: 19/07/2018
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9. CORRELAÇÕES GEOQUÍMICAS ENTRE AMOSTRAS DE PETRÓLEO DA BACIA POTIGUAR E DEFINIÇÃO DE SUAS POSSÍVEIS ROCHAS GERADORAS
Eight petroleum samples from Potiguar Basin were submitted for determination of saturated biomarkers by gas chromatography (fingerprint), liquid chromatography (saturates, aromatics, resins and asphaltenes), gas chromatography-mass spectrometry (GC-MS), nickel and vanadium by high resolution continuum source graphite furnace atomic absorption spectrometry (H
Quím. Nova. Publicado em: 2018-04
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10. Comparative analysis of niobium and vanadium carbide efficiency in the high energy mechanical milling of aluminum bronze alloy
Abstract This study aims to analyze the efficiency of niobium and vanadium carbides in the high energy mechanical milling of aluminum bronze alloy. Two series of experiments were made following the same steps for both niobium carbide (NbC) and vanadium carbide (VC) additions: 30 g of chips were weighed and placed in a stainless steel jar with 3 % of carbide
REM, Int. Eng. J.. Publicado em: 2018-03
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11. Electroremediation of deactivated catalysts from fluidised catalytic cracking for vanadium removal - the effect of a dual cathode chamber reactor
Abstract The aim of this study was to evaluate the quantity of vanadium removed through electrokinetic remediation applied to catalyst waste used in a fluid catalytic cracking process. In excess, vanadium affects process efficiency by reducing the catalyst’s activity, causing deactivation and reducing its useful life in petroleum cracking during refining.
Braz. J. Chem. Eng.. Publicado em: 2018-01
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12. Efecto del V y el Si Sobre la Microestructura de Depósitos Realizados con Electrodos Tubulares Revestidos de Alto Contenido de Mn (Hadfield)
Abstract: Fe-Mn-C (Hadfield) alloys for surfacing weld deposits have demonstrated excellent wear resistance under high dynamic loads. In recent years, numerous studies have been conducted to improve their wear resistance and performance through the introduction of others alloying elements. In the present work, microstructure and hardness of high Mn surfacing
Soldag. insp.. Publicado em: 09/10/2017