Recent Papers - Machine Learning Special Issue
Reviews/Accounts - last 5 years
A Simple and Fast Procedure for in situ Determination of Water in Ethanol Fuel
Mauricio S. Ribeiro; Lúcio Angnes; Fábio R. P. Rocha
How to cite this articleA simple procedure was developed for determination of water content in ethanol fuel exploiting the differences in solubility of sodium chloride in aqueous and organic media. Based on the same principle, an inexpensive device was constructed aiming at in-situ detection of unconformities in ethanol fuel. The device can be operated even by non-experts and yields a binary response indicated by colored LEDs. Details are presented in the Article A Simple and Fast Procedure for in situ Determination of Water in Ethanol Fuel by Mauricio S. Ribeiro, Lúcio Angnes and Fábio R. P. Rocha on page 418.
Éderson D'Martin Costa; Nelson H. T. Lemes; Márcio O. Alves; Rita C. O. Sebastião; João P. Braga
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Parametric sensitivity analysis as a function of temperature for one parameter in the short-range region of the potential and for three parameters in the long-range regions of the potential.
José Eduardo de Albuquerque; Bruno C. L. Santiago; Júlio César C. Campos; Alexandre M. Reis; Charles L. da Silva; João Paulo Martins; Jane S. R. Coimbra
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Experimental setup of the photothermal spectrometer used to follow edible oil degradation by heating process. The physicochemical properties of the studied vegetable oils indicate changes in the concentration of fatty acid and in polar substances after thermal degradation.
Lúcia F. A. Garcia; Sérgio M. Corrêa; Renato Penteado; Luiz Carlos Daemme; Luciana V. Gatti; Debora S. Alvim
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High volatile organic compound emissions derived from motorcycles and the increase of the fleet of such vehicles can lead to increased levels of ozone in Brazilian cities.
Zhi Zheng; Jianli Wang; Zhen Lu; Min Luo; Miao Zhang; Lixin Xu; Jianbing Ji
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In this work, the hydrogenolysis of 2-tosyloxy-1,3-propanediol (TPD) into 1,3-propanediol (1,3-PD) over Raney Ni catalyst at different reaction parameters was discussed to optimize the reaction conditions for selective formation of 1,3-propanediol.
Chunxiu Xu; Longfei Cai
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The labeled cells were hydrodynamically focused by sheath-flow streams and sequentially introduced into the sampling channel under hydrostatic pressure generated by adjusting liquid levels in the reservoirs. Intracellular reducing level in intact living L02 cells was detected by laser induced fluorescence (LIF) without cytolysis.
Elivelton A. Ferreira; Rodrigo Della Noce; Cecílio S. Fugivara; Assis V. Benedetti
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Electrochemical impedance spectroscopy (EIS) diagrams of AISI 316L stainless steel in aqueous solution and in a mixture of 35 wt.% water and 65 wt.% ethanol, both containing 1 wt.% H2SO4 plus 0.35 wt.% NaCl, at 25 °C, evidencing the differences between the ethanolic and aqueous solution resistances.
Mahendra N. Lokhande; Manojkumar U. Chopade; Dattatrya N. Bhangare; Milind D. Nikalje
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An approach for desymmetrization of glycerol by using readily available camphorsulfonamide to obtain chiral glycerol derivate (enantioselectivity, ee > 95%) is described. The resultant chiral glycerol derivative is used in asymmetric synthesis of β-blockers (S)-propranolol, (S)-naftopidil and (R)-monobutyrin.
Irajá N. Filho; Nathália C. Vieceli; Eduardo M. Cardoso; Eduardo R. Lovatel
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The volatilization of BTEX in experimental columns with and without ethanol was evaluated. Toluene and ethylbenzene showed the highest volatilizations in the gasoline-ethanol column, probably by attractive intermolecular forces.
Mauricio S. Ribeiro; Lúcio Angnes; Fábio R. P. Rocha
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Low cost and portable electronic device proposed for conductivity measurements aiming in situ determination of water content in ethanol. The solubility of sodium chloride and the conductivity is proportional to the water content in ethanol fuel, when excess of the salt is used.
Valeska S. Aguiar; Carla B. G. Bottoli
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This figure shows the operation scheme of the capillary electrochromatography system. The major difference between this one and the conventional capillary electrophoresis system is the use of a capillary column packed with stationary phase. The stationary phase in the zoomed picture is an octadecyl methacrylate-based monolith.
Saraghina M. D. Cunha; Ramon G. de Oliveira; Mário L. A. A. Vasconcellos
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Five convenient 2-indolizine derivative syntheses from Morita-Baylis-Hillman adducts are presented. They were realized as potential ion channel blockers based on score results by Molinspiration Cheminformatics program.
Adriana Mika; Edward Skorkowski; Piotr Stepnowski; Marek Gołębiowski
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Scheme of the lipid analysis of Crangon crangon abdominal muscle. Triacylglycerols: TAG, polar lipid: PL, free fatty acid: FFA and
Rosa Vera; Fabián Guerrero; Diana Delgado; Raquel Araya
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This study focuses on the behavior of galvanized steel in a corrosive marine environment and on the rainwater runoff process for the same material in the city of Valparaiso, Chile. After one year, the total Zn loss due to the runoff process is practically negligible compared to the mass loss of the galvanized steel due to atmospheric corrosion.
Marilia M. S. Pupo; Lucas S. da Costa; Aíle C. Figueiredo; Ronaldo S. da Silva; Frederico G. C. Cunha; Katlin I. B. Eguiluz; Giancarlo R. Salazar-Banda
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Wastewater contaminated with indanthrene blue dye was treated with a photoelectrocatalytic system. Different Ti/Ru-based electrodes were synthesized, chemically and physically characterized, and used for dye removal.
Raphael da S. Affonso; Ana P. Guimarães; Aline A. Oliveira; Glaucia B. C. Slana; Tanos C. C. França
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Superpositions of eugenyl acetate and N,N-diethyl-3-methylbenzamide (DEET) inside the monomers (a) and (b) of Anopheles gambiae odorant binding protein (AgOBP1).
Maristela F. Amadori; Gilcélia A. Cordeiro; Caio C. Rebouças; Patricio G. Peralta-Zamora; Marco T. Grassi; Gilberto Abate
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This study reports the optimization of the experimental conditions to extract the herbicide atrazine and its main degradation products from an oxisol sample with subsequent quantification by HPLC. The method revealed appropriate recovery values for different soil depths (00-10, 10-30 and 30-50 cm), using a simple and fast extraction method.
Rafael C. E. Dias; Adelia F. de Faria; Adriana Z. Mercadante; Neura Bragagnolo; Marta de T. Benassi
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In order to analyze diterpenes from roasted coffee by HPLC-DAD-MS/MS, four methods of sample preparation were tested. Direct hot saponification presented the best efficiency. Kahweol, cafestol and dehydro derivatives were identified and quantified.
Talita de A. Fernandes; Boniek G. Vaz; Alcides J. M. da Silva; Pierre M. Esteves; Marcos N. Eberlin; Paulo R. R. Costa
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Stereospecific palladium-catalyzed arylation of E- and Z-enoates with iodobenzene in acetone using Ag2CO3 as base led to Z- and E-cinnamates, respectively. The reaction course was monitored by electrospray ionization mass spectrometry (ESI-MS).
Nathália V. S. Rodrigues; Eduardo M. Cardoso; Marcus V. O. Andrade; Cláudio L. Donnici; Marcelo M. Sena
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A mid-infrared method jointly with an exploratory chemometric model was developed for the analysis of seized cocaine samples and characterization of its adulterants. Two supervised models were established to classify samples according to their content and cocaine form, providing a rapid and non-destructive tool of great utility in criminal investigations.
Peng Wang; Jin Cai; Jiabin Yang; Chunlong Sun; Lushen Li; Min Ji
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This study reports the regioselective Dakin oxidation of trans-chalcones with hydrogen peroxide in acetonitrile. A variety of cinnamic acids as the main products were obtained.
Berrak Başbuğ; Şerife Tokalıoğlu
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Online version ISSN 1678-4790 Printed version ISSN 0103-5053
Journal of the Brazilian Chemical Society
JBCS Editorial and Publishing Office
University of Campinas - UNICAMP
13083-970 Campinas-SP, Brazil
Free access