Pore Volume
Mostrando 1-12 de 138 artigos, teses e dissertações.
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1. Optimization and Study of the Response Surface of Properties for the Synthesis of ZSM-5 Zeolites with Hierarchical Pore Structure Obtained by Desilication
Hierarchical ZSM-5 zeolites were prepared by alkali treatment (desilication) at two temperatures, two reaction times, and two NaOH concentrations. A 23 factorial design was used to study the effect of these variables on the crystallinity, microporosity, and mesoporosity of the zeolite due to the desilication treatment. The factorial design analysis showed th
J. Braz. Chem. Soc.. Publicado em: 2021-06
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2. Porosity of CHA Zeolite Driving the Formation of Polyaromatic Coke Species in the Methanol to Olefins Reaction
The pore size of the chabazite structure is exceptionally suitable for the methanol to olefins (MTO) reaction. The reaction has an induction period required for the formation of a hydrocarbon pool (HP), usually composed of aromatic compounds of different sizes. HP is alkylated by methanol and afterward cracked, leading to the formation of olefins. Despite th
J. Braz. Chem. Soc.. Publicado em: 2021-05
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3. Reordering of Depolymerized Silicates as Adsorbents for Large Nitrogen Compounds
The adsorption capacities of two synthesized zeolites (crystalline ZSM-5 and semi-crystalline faujasite Y) for a mixture of indole, quinoline and carbazole were studied. The different samples obtained show different crystalline degree, mesoporosity and Si/Al ratios. The synthesis procedure is based on the simultaneous depolymerization of a mixture of high su
J. Braz. Chem. Soc.. Publicado em: 2021-01
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4. Development of Geopolymers for Catalyst Support Applications
A geopolymer with high specific surface area was synthesized from metakaolin, amorphous silica and KOH, in the absence of foaming or saponification agents. The mixture modelling technique was selected for this study among the Design of Experiments tools, using surface area and total pores volume as response variables. The Si/K = 2.46 and Si/Al = 1.37 ratios
Mat. Res.. Publicado em: 25/11/2019
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5. Effect of Egg Weight on External and Internal Qualities, Physiological and Hatching Success of Japanese Quail Eggs (Coturnix coturnix japonica)
ABSTRACT This experiment was conducted to evaluate the effect of egg weight and egg physical characteristics on embryonic development, hatchability, and hatchling weight of Japanese quails (Coturnix coturnix japonica). In total, 689 eggs were classified in two categories: small (<13.5 g) or large (≥13.5 g), and different external eggshell and internal qual
Braz. J. Poult. Sci.. Publicado em: 11/11/2019
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6. Silica/Titania Graphite Composite Modified with Chitosan and Tyrosinase Employed as a Sensitive Biosensor for Phenolic Compounds
A mesoporous, high surface area and conductive silica/titania graphite composite modified with chitosan and functionalized with tyrosinase was prepared. The composite was obtained by the sol-gel method and the surface of the resultant material was modified with chitosan solutions containing 5, 10 and 15% by mass. The textural characterization showed that eve
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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7. Iron oxide/titania composites for radar absorbing material (RAM) applications
Resumo Compósitos de óxido de ferro/titânia foram sintetizados pelo método de precipitação. A quantidade de óxido de ferro foi variada nos compósitos. Fase única (anatásio) foi obtida para a fração em massa de 0-20% e três fases (anatásio, magnetita e hematita) foram encontradas para as frações de 30% e 40% de óxido de ferro. O tamanho de cr
Cerâmica. Publicado em: 15/08/2019
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8. Water retention curve to analyze soil structure changes due to liming
Abstract: Liming can influence crop growth by altering pore geometry, pore size distribution and water retention characteristics in acid soils. The aim of this work is to determine liming effects on the soil structure based on analysis of water retention data using a cubic spline adjustment function. For that, the authors investigated the effect of three lim
An. Acad. Bras. Ciênc.. Publicado em: 03/06/2019
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9. Seleção de carvões ativados para adsorção de microcistinas
RESUMO A presença das cianobactérias é uma das grandes preocupações para o tratamento de água, uma vez que esses microrganismos podem ser produtores de metabólitos tóxicos, como as microcistinas (MCs), que não são efetivamente removidas no tratamento usualmente empregado de ciclo completo. Para a remoção dessas toxinas, pode-se, de forma compleme
Eng. Sanit. Ambient.. Publicado em: 30/05/2019
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10. 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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11. Desenvolvimento de espumas vítreas a partir de garrafa e casca de ovo
RESUMO Este trabalho tem como foco a produção de espumas vítreas a partir de materiais reciclados, fazendo uso de matéria-prima de fácil acesso local e alta incidência no mercado: garrafas de cerveja não retornáveis e casca de ovo, como agente espumante. Para tanto, investigou-se a influência da temperatura de queima, da granulometria do vidro precu
Matéria (Rio J.). Publicado em: 20/05/2019
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12. Reduction of electric arc furnace dust pellets by mixture containing hydrogen
Abstract The large amount of dust generated in electric arc furnace aligned with its chemical composition makes this dust a potential source of iron in the direct reduction iron process. Thus, the aim of this research is to investigate the reduction of pellets produced with electric arc furnace dust using hydrogen as the reducing agent. The kinetic investiga
REM, Int. Eng. J.. Publicado em: 2019-03