Refractory Elements
Mostrando 1-12 de 41 artigos, teses e dissertações.
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1. 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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2. CHARACTERIZATION OF SEVERAL GENERATIONS OF NiMo HYDROPROCESSING CATALYSTS EMPLOYED IN THE SAME HYDROTREATER
This work details the chemical characterization of four NiMo/Al2O3 hydroprocessing generation catalysts (1979-1986, 1993-1998, 2003-2008 and 2008-2011) employed to perform hydrodesulfurization (HDS) of diesel fractions in the same hydrotreater of a Brazilian refinery. The basic differences are the quality of the feedstocks and the HDS experimental conditions
Quím. Nova. Publicado em: 27/05/2019
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3. LA PERIODICIDAD DE LOS ELEMENTOS Y EL DESEMPEÑO DE LOS MATERIALES: UN COMPLEMENTO PARA LA COMPRENSIÓN DE LA TABLA PERIÓDICA
The United Nations (UN) has proclaimed 2019 as the International Year of the Periodic Table of Chemical Elements (IYPT 2019). For that reason, it is considered pertinent to highlight the importance of the periodic system in the scientific and technological development of the chemistry; therefore, a discussion of some applications of the periodicity of the el
Quím. Nova. Publicado em: 2019-02
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4. Blast Furnace Hearth Lining: Post Mortem Analysis
The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 ºC for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair o
Mat. Res.. Publicado em: 15/05/2017
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5. Analysis of energetically biased transcripts of viruses and transposable elements
RNA interference (RNAi) is a natural endogenous process by which double-stranded RNA molecules trigger potent and specific gene silencing in eukaryotic cells and is characterized by target RNA cleavage. In mammals, small interfering RNAs (siRNAs) are the trigger molecules of choice and constitute a new class of RNA-based antiviral agents. In an efficient RNA
Genet. Mol. Biol.. Publicado em: 13/11/2012
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6. Increasing pathomorphism of pulmonary tuberculosis: an observational study of slow clinical, microbiological and imaging response of lung tuberculosis to specific treatment. Which role for linezolid?
During recent years, a progressive emerging of tuberculosis occurred, related to the overall increased age of general population, primary and secondary (iatrogenic) immunodeficiencies, the availability of invasive procedures, surgical interventions and intensive care supports, bone marrow and solid organ transplantation, and especially the recent immigration
Brazilian Journal of Infectious Diseases. Publicado em: 2009-08
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7. Alteridade e Diálogo: uma meta-aqueologia da educação a partir de Emmanuel Lévinas e de Paulo Freire.
The meta-archeology of Education, suggested in this work, refers to Emmanuel Lévinas and Paulo Freire and wants to orientate a philosophical reflection about the questions raised by the necessity of looking at the Other as a source of learning that enables the human being to be more. The problem concerning this research may be explained as follows: How can
Publicado em: 2007
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8. Aplicabilidade das argilas do município de Sapopema e Curiúva (PR) na indústria artesanal de cerâmica e suas implicações no contexto socioeconômico
The propose of this study has for objective the characterization of the clay material of the ceramist regions of the Sapopema city, in Paraná State, and the verification of the ceramic potencial of that mineral material, for commercial ends, aiming at the dynamization of the local economy in that region. Clays collected had been characterized through morpho
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/11/2005
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9. DETERMINATION OF REFRACTORY ELEMENTS IN USED LUBRICATING OIL AND IN FUEL OIL BY ICP OES WITH EMULSIFIED SAMPLES / DETERMINAÇÃO DE ELEMENTOS REFRATÁRIOS EM ÓLEO LUBRIFICANTE USADO E EM ÓLEO COMBUSTÍVEL POR ICP OES APÓS EMULSIFICAÇÃO DA AMOSTRA
O conhecimento da concentração dos elementos traço em óleo lubrificante usado é útil para a avaliação de desgastes de componentes específicos de motores.Em óleo combustível, este monitoramento permite avaliar a qualidade do combustível e prever o potencial das emissões de metais no meio ambiente. Neste trabalho, utilizou-se a espectrometria de e
Publicado em: 2003
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10. Caracterização de escorias e recuperação do silicio / Characterization of slag and recovery of the silicon
Metallurgieal Grade Silicon (MGSi) is produced by a well-established industrial process that consists of the carbo-reduction of quartz in a submerged are fumace under high temperature. The process is an intensive energy consumption method (13 - 15 kWh to each kilogram of produced MGSi). After tapered, the MGSi is submitted to some purification stages in orde
Publicado em: 2003
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11. Estudo de modificadores quimicos e superficies modificadas para a determinação de estanho por espectrometria de absorção atomica com forno de grafite
Tin is an important element from an environmental viewpoint and is essential for humans at trace levels. However, the direct determination of tin by graphite furnace AAS has been fraught with problems such as volatilization loss, interaction with the graphite surface and sample matrix interference. In the present work, the use of the calcium, barium and stro
Publicado em: 1997
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12. Displasias corticais associadas a epilepsia : delineamento de uma nova sindrome, revisão de conceitos localizacionais e proposta de uma nova classificação
Modemneuro:imagingtechniques current1y allows lin vivo I identification of cortical dysplastic lesions in patients previously thought to have cryptogenic epilepsies. These lesions constitute an heterogenous group of disorders from clinicall anatomical, histopathological, and pathogenetic standpoints. The fact that such heterogeneity is not readily realized o
Publicado em: 1996