Engenharia Química
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/25
Navegar
15 resultados
Resultados da Pesquisa
Artigo de evento 0 Citação(ões) na Scopus Calorimetric measurement of the interface energy of pure and calcium doped magnesium oxide(2009-10-29) CASTRO, R.; Ricardo Torres; GOUVEA, D.Interface energetics is of key importance in understanding the evolution of nanoparticles during sintering. During this process, two types of interfaces control the driving forces: the surface and the grain boundary. The knowledge of their energies is therefore of major importance to obtain reliable sintered bodies. The objective of this work was to present a quantitative relationship between the grain boundary energy and the surface energy of MgO and Ca-doped MgO nanoparticles to provide data to better understand the sintering behavior of this system, in particular delineating the thermodynamic basis of using Ca as sintering add. Using a novel and convenient calorimetric procedure, the ratio between the grain boundary energy and the surface energy was determined to be 1.1 for pure MgO and 0.7 for Ca-doped MgO. Based on these, the grain boundary energy of pure MgO and Ca-doped MgO were estimated to be 1.2 J.m-2 and 0.4 J.m-2, respectively. The grain boundary energy decrease caused by calcium doping was attributed to its interface segregation and influenced the sintering behavior by changing the equilibrium dihedral angle in addition to diffusion parameters.Artigo de evento 0 Citação(ões) na Scopus Density and speed of sound of binary mixtures of (diethyl malonate + methanol) at different temperatures and atmospheric pressure(2014-11-16) LIBORIO, M. N.; Ricardo TorresArtigo de evento 0 Citação(ões) na Scopus Influence of feedstock on biodiesel corrosiveness and degradation(2014-11-16) Isabella Aquino; ALVES, T. P.; SILVA, F. F. R; AOKI, I. V.; Ricardo TorresArtigo de evento 1 Citação(ões) na Scopus Influence of the synthetic antioxidants, BHT and TBHQ, on soybean biodiesel corrosiveness and degradation(2015-11-08) Isabella Aquino; CELIBERTO, B. P.; ALVES, T. P.; AOKI, I. V.; Ricardo Torres- Measurement and correlation of high-pressure volumetric properties of binary mixtures of 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) with alcohols(2023-10-05) HAUK, D. B.; Ricardo Torres; DANGELO, J. V. H.© 2023 Elsevier LtdNew experimental data for density-pressure–temperature measurements of binary mixtures of {1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) + methanol, or + ethanol or + 1-propanol} have been measured using a vibrating tube densimeter at temperatures from T = (298.15 to 308.15) K and pressure range p= (0.1 – 40) MPa. The experimental density results have been correlated by the Tait-Tammann equation with the temperature and composition dependence parameters. The effects of the increase in the alkyl chains of the alcohols, temperature, and pressure on the density and volumetric properties have been analyzed. Moreover, the Extended Real Associated Solution Model (ERAS Model) has been used to correlate the experimental behavior of the excess molar volume of the studied systems.
- Experimental study and correlation of the excess molar volume of binary liquid solutions of (amines + water) at different temperatures and atmospheric pressure(2022-03-05) MUNOZ, P. A. R.; OLIVIERI, G. V.; Ronaldo Santos; Ricardo Torres© 2021, Associação Brasileira de Engenharia Química.Experimental data of density have been measured for binary liquid mixtures containing {amines (n-butylamine, or s-butylamine, or t-butylamine, or diethylamine, or propylamine) + water}, over the entire range of composition at temperatures between 283.15 and 303.15 K, and atmospheric pressure. The density values enabled the determination of the thermal expansion coefficients. The excess molar volume, VmE, was calculated using the experimental data, from which a Redlich–Kister type polynomial was fit, enabling the determination of the partial molar volumes, the excess partial molar volumes, the apparent molar volumes and the excess partial molar volumes at infinite dilution. The VmE values were also used to test the applicability of the Extended Real Associated Solution Model (ERAS Model). The results for the studied systems suggest that structural effects and chemical interactions must predominate over other possible effects. The magnitude of VmE for the studies systems led to the following order: n-butylamine > propylamine > s-butylamine > diethylamine > t-butylamine.
- Molecular interactions of (ionic liquid butylammonium methanoate + alcohols) at several temperatures. Part II: sec-Butylammonium methanoate (S4Met)(2023-04-05) HOGA, H. E.; FERNANDES, R. L.; OLIVIERI, G. V.; Ricardo Torres© 2022 Elsevier LtdVolumetric and acoustic properties were obtained by density (ρ) and speed of sound (u) experimental values for the binary liquid systems containing the protic ionic liquid (IL) sec-butylammonium methanoate (S4Met) + alcohols (ethanol, 1-propanol, 1-butanol and 1-pentanol) over the whole composition range at different temperatures (293.15–313.15) K and ambient pressure (p = 92.3 kPa). A neutralization reaction was carried out under controlled temperature to synthesize S4Met, which underwent spectroscopic analyses to guarantee its formation. All the excess properties, namely excess molar volume,VmE, excess partial molar volumes,V¯iE, and deviation in isentropic compressibility,ΔκS, presented negative values. Other volumetric properties such as partial molar volumes,V¯i, apparent molar volumes, Vϕi and infinite dilution volumes,V¯i∞, were determined. In addition to the thermodynamic approach, spectroscopy techniques essentially 1H NMR, 13C NMR, FTIR were useful in order to elucidate intermolecular interactions among the species in solutions. Lastly, the Peng-Robinson-Stryjek-Vera equation of state (PRSV EOS) was used to correlate the excess molar volumes.
- Measurement and correlation of thermodynamics properties of aqueous solutions containing glycols. Part II: Excess molar enthalpy(2023-02-05) HOGA, H. E.; Ricardo Torres; OLIVEIRI, G. V.; VOLPE, P. L. O.© 2022 Elsevier LtdIn this work, excess molar enthalpies of binary liquid mixtures of {water + ethanol, or + ethylene glycol, or + diethylene glycol, or + triethylene glycol, or + poly(ethylene glycol) 200, or + poly(ethylene glycol)300, or + poly(ethylene glycol)400, or + poly(ethylene glycol)600, or + glycerol} have been determined as a function of composition using a microcalorimeter Thermal Activity Monitor (2277, Thermometric) at 298.15 K and atmospheric pressure. The results were fitted by the Myers-Scott equation, as a function of mole fraction. The values of excess molar enthalpies were exothermic and large. The excess partial molar enthalpies and excess partial molar enthalpies at infinite dilution were calculated. Moreover, the experimental results were used to test the applicability of the Wilson, NRTL and UNIQUAC models. The results of excess molar enthalpies were discussed in terms of molecular interactions.
- Volumetric, acoustic and viscometric properties of binary mixtures containing acetonitrile with glycols at several temperatures: Experimental study and correlations(2022-10-01) ROSA MILLE, M.; EMI HOGA, H.; VIEIRA, OLIVIERI, G.; Ricardo Torres© 2022 Elsevier LtdDensity, speed of sound and viscosity of binary mixtures of {acetonitrile + ethylene glycol (EG), or + diethylene glycol (DEG), or + triethylene glycol (TEG)} have been measured as a function of compositions at temperatures of 288.15, 293.15, 298.15 and 303.15 K and under atmospheric pressure. Excess molar volume, partial molar volume, excess partial molar volume, deviation in isentropic compressibility and deviation in viscosity were determined and excess properties have been fitted to the Redlich-Kister equation. The empirical models developed by Grünberg-Nissan, Heric-Brewer, Katti-Chaudhary and Van der Wyk were used to correlate the experimental viscosity data. The excess molar volume was also used to test the applicability of the Peng-Robinson-Stryjek-Vera equation of state (PRSV EOS).
- Binary mixtures of {1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][triflate]) + alcohols} at high-pressure: A thermodynamic, spectroscopic and correlation approach(2022-06-05) BENESTANTE HAUK, D.; Ricardo Torres; VICENTE HALLAK DANGELO, J.© 2022 Elsevier LtdThe density of binary mixtures of {1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][triflate]) + alcohols} has been measured at temperatures from (298.15 to 308.15) K and pressures from (0.1 to 40) MPa. The effect of temperature and pressure on density and calculated excess molar volumes, partial molar volumes, apparent molar volumes and partial molar volumes at infinite dilution was analyzed. The experimental density results were correlated by using the Tait-Tammann equation to deduce isothermal compressibility and isobaric expansivity. In addition to the thermodynamic study, some spectroscopic properties (H-NMR, C-NMR and FT-IR) were presented to elucidate some possible molecular interactions between the components under study. Furthermore, the Extended Real Associated Solution Model (ERAS Model) was applied to correlate the values of excess molar volume.