Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 59 )

2018 ( 380 )

2017 ( 398 )

2016 ( 456 )

Custom range...

Search Results: 1 - 10 of 235181 matches for " Marcelo José Barros de Souza "
All listed articles are free for downloading (OA Articles)
Page 1 /235181
Display every page Item
Conversion of Isopropylbenzene over AlSBA-15 Nanostructured Materials  [PDF]
Francine Mota Ribeiro, Anne Michelle Garrido Pedrosa, Marcelo José Barros de Souza
Modern Research in Catalysis (MRC) , 2014, DOI: 10.4236/mrc.2014.33012

In this paper we studied the application of a series of AlSBA-15 catalysts with different Si/Al ratios on the reaction of conversion of isopropylbenzene. The catalysts were synthesized via hydrothermal method and characterized by nitrogen adsorption at 77 K and Small Angle X-ray Scattering (SAXS). Catalytic tests were accomplished in a continuous flow fixed bed microreactor. The obtained results showed catalytic activity for all AlSBA-15 catalysts producing benzene and propene as main products.

Catalytic Esterification of Oleic Acid Over SO42-/MCM-41 Nanostructured Materials  [PDF]
Alexsandra Rodrigues do Nascimento, Gicélia Rodrigues, Joselaine Carvalho Santana, Anne Michelle Garrido Pedrosa, Marcelo José Barros de Souza
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.26097
Abstract: This paper deals a study concerning the synthesis and catalytic application of a series of SO42-/MCM-41 catalysts with different SO42-/Si ratios, in the catalytic esterification of oleic acid, aiming biofuels production. The catalysts were characterized by XRD and FT-IR. The catalytic tests were carried out in a batch reactor and the obtained results showed good catalytic activity with high degrees of conversions of oleic acid.
Synthesis and Characterization of LaNixCo1-xO3 Perovskites via Complex Precursor Methods  [PDF]
Grace Rafaela Oliveira Silva, José Carlos Santos, Danielle M. H. Martinelli, Anne Michelle Garrido Pedrosa, Marcelo José Barros de Souza, Dulce Maria Araujo Melo
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.12008
Abstract: This work presents a study on the synthesis of LaNixCo1-xO3 perovskites via complex precursor methods. Perovskite oxides with the composition LaNixCo1-xO3 were synthesized by chelating precursor and polymeric precursor methods using nickel and/or cobalt nitrates, lanthanum nitrate, ethylene glycol, citric acid, and EDTA as starting source. The obtained perovskite were characterized by thermogravimetric analysis, infrared spectroscopy, X-ray diffraction and the morphology of the samples were investigated by N2 adsorption experiments and average medium particle size. TG curves and FTIR spectra were particularly useful in establishing of the optimal calcination temperature of the precursor powders. X-ray diffraction patterns revealed the formation of the perovskite structure in all samples prepared by both synthesis method and after calcinations at 700℃. The results showed that the preparation method resulted in oxides with the intended structure. The specific surface area values were influenced by preparation method.
Síntese da perovsquita do tipo LaNiO3 através do método dos precursores quelantes usando EDTA: otimiza??o do teor de agente quelante
Santos, Jose Carlos dos;Pedrosa, Anne Michelle Garrido;Mesquita, Maria Eliane;Souza, Marcelo José Barros de;
Química Nova , 2011, DOI: 10.1590/S0100-40422011000800008
Abstract: the perovskites are strategic materials due their catalytic, electronic and magnetic properties. these properties are influenced by the calcination and synthesis conditions. in this work was carried out the synthesis of lanio3 perovskite-type by chelating precursor method using edta and also was studied the optimization of the edta content in the synthesis. the synthesized materials were characterized by x-ray diffraction (xrd), thermal gravimetric analysis (tg) and infrared spectroscopy (ftir). in the optimization of the edta content the lowest ratio of metal / edta used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite.
Análise econ?mica de sistemas de produ??o a pasto para bovinos no município de Campos dos Goytacazes-RJ
Peres, Afonso Aurélio de Carvalho;Souza, Paulo Marcelo de;Maldonado, Hernan;Silva, José Fernando Coelho da;Soares, Cezar da Silva;Barros, Suzana Correa Wagner;Haddade, Ismail Ramalho;
Revista Brasileira de Zootecnia , 2004, DOI: 10.1590/S1516-35982004000600023
Abstract: different economic viability of pasture production systems to heifers grazing elephantgrass pasture in north fluminense region wa analyzed. the economical analysis of three systems of growing fedlot dairy heifers grazing elephantgrass pasture was performed. in order to study the hazard that each system can present due to the oscillations of prices in the market, monte carlo simulation was used. the systems studied were: without supplementation (ps1), offer of 0.5% of the alive weight of concentrate (ps2), and alternate pasture of elephantgrass and stylosanthes (ps3). the analysis was based on the economical indicators net present value (npv) and internal rates of return (irr). the npv calculated at an annual rate of discount of 10%, were r$ 6,091.86, r$ 6,364.54 and r$ 215.43, while the invested capital showed yearly irr of 29.58, 30.10 and 10.46%, respectively for three systems studies. the sensitivity analysis was used to identify the items of larger economical impact and that presented great effect on the profitability of the systems. in order of importance, the sale price of heifers, the purchase price of heifers and the labor cost were the items with greater impact on the economical results. it was concluded that the ps3 showed the highest economical stroke.
Si3N4 ceramic cutting tool sintered with CeO2 and Al2O3 additives with AlCrN coating
Souza, José Vitor Candido;Silva, Olivério Moreira de Macedo;Nono, Maria do Carmo Andrade;Machado, Jo?o Paulo Barros;Pimenta, Marcelo;Ribeiro, Marcos Valério;
Materials Research , 2011, DOI: 10.1590/S1516-14392011005000077
Abstract: ceramic cutting tools are showing a growing market perspective in terms of application on machining operations due to their high hardness, wear resistance, and machining without a cutting fluid, therefore are good candidates for cast iron and nickel superalloys machining. the objective of the present paper was the development of si3n4 based ceramic cutting insert, characterization of its physical and mechanical properties, and subsequent coating with alcrn using a pvd method. the characterization of the coating was made using an optical profiler, xrd, afm and microhardness tester. the results showed that the tool presented a fracture toughness of 6.43 mpa.m1/2 and hardness of 16 gpa. the hardness reached 31 gpa after coating. the machining tests showed a decrease on workpiece roughness when machining with coated insert, in comparison with the uncoated cutting tool. probably this fact is related to hardness, roughness and topography of alcrn.
Alongamento do processo estilóide (síndrome de Eagle): relato de dois casos
, Antonio Carlos Domingues de;Zardo, Maurício;Paes Junior, Ademar José de Oliveira;Souza, Ricardo Pires de;Barros Neto, Francisco;Dreweck, Marcelo de Oliveira;Oliveira, Regiane de;Neme, Murilo Postiglioni;Rapoport, Abr?o;
Radiologia Brasileira , 2004, DOI: 10.1590/S0100-39842004000500015
Abstract: elongated styloid process or eagle's syndrome is a multifactorial disease with unspecific characteristics on clinical and imaging examinations. the use of imaging methods in combination with the signs and symptoms are valuable in the confirmation of the diagnosis since they show the extension of the styloid complex, the muscles and ligaments, and adjacent structures. the diagnosis can be established when there is an association of clinical information and imaging findings. the authors report two cases of elongated styloid process including the imaging findings, mainly obtained using computed tomography.
Composi??o físico-química e produ??o do leite de búfalas da ra?a Mediterraneo no oeste do Estado de S?o Paulo
Macedo, Marcelo Pereira;Wechsler, Francisco Stefano;Ramos, Alcides de Amorim;Amaral, Jackson Barros do;Souza, Júlio César de;Resende, Flávio Dutra de;Oliveira, José Victor de;
Revista Brasileira de Zootecnia , 2001, DOI: 10.1590/S1516-35982001000400024
Abstract: the objective of this study was to evaluate milk yield and some physico-chemical characteristics of milk from mediterranean buffalo cows raised in western s?o paulo. a total of 1438 observations was collected from 152 lactations that occurred from 1985 to 1995, at the experimental station of andradina. the data were analyzed by means of the glm procedure of sas. the statistical model for milk production had month and lactation as fixed effects. the model for chemical constituents included milk yield as covariate. all effects were significant. the overall adjusted means were 4.52 kg, 4.13%, 6.59%; 17.01%, 10.47% and 18.98°d for milk production, protein, fat and total solids, solids not fat and titratable acidity, respectively. high nutrient contents were observed, which shows the good quality of the product.
A "Ingovernabilidade" do Rio de Janeiro - Algumas Páginas sobre Conceitos, Fatos e Preconceitos
Marcelo José Lopes de Souza
Anuário do Instituto de Geociências , 1997,
"Espaciologia" - uma Obje o
Marcelo José Lopes de Souza
Anuário do Instituto de Geociências , 1986,
Page 1 /235181
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.