Juan Lanz

Temperature influence on refractive indices and isentropic compressibilities of alcohol (C2–C4)+olive oil mixtures

This paper presents isentropic compressibilities and refractive indices on mixing of mixtures enclosing short aliphatic alkanols (ethanol, 1-propanol, 2-propanol and 1-butanol) with olive oil that have been measured in the temperature range from 283.15 to 298.15 K and atmospheric pressure. The values of these properties were calculated in all range of homogeneous composition, phase splitting appearing in the mixtures (ethanol or 2-propanol) with olive oil. From the mentioned properties, derived properties such as compressibility solvation numbers, isentropic apparent molar compressibility and changes of magnitudes were calculated. The enhanced packing efficiency of alcohols at low molar fractions is strongly affected by steric hindrance of aliphatic residues, although dimers or rings of alcohol molecules are formed at high concentrations when residue end of alkanol is small. Different mixing rules for refractive indices on mixing were applied, as well as the collision factor theory (CFT) formulation for isentropic compressibilities. The thermal pressure coefficients of these solvents were analysed as a function of the temperature, their shape and trend being commented upon.

Excess molar volumes of binary mixtures containing vinyl acetate + alkyl acetates at 298.15 K. Anomalous behavior of methyl acetate + vinyl acetate mixtures

Abstract Excess molar volumes for binary mixtures containing vinyl acetate + methyl acetate, +ethyl acetate, +propyl acetate, +isopropyl acetate, +butyl acetate, +isobutyl acetate, +pentyl acetate, +isopentyl acetate have been determined from density measurements at 298.15 K using an Anton Paar DMA 58 vibrating tube densitometer. A maximum in densities has been observed for the methyl acetate + vinyl acetate system, where samples with different composition showed the same density. Excess molar volumes increase with an increase of the size of the second acetate.

Excess Volumes for Binary Mixtures Formed by Methyl Acetate with Aromatic Hydrocarbons

Excess molar volumes for binary mixtures containing methyl acetate + methylbenzene, ethylbenzene, 1,4-dimethylethylbenzene, 1-methylbenzene, 1,-3,-5-trimethylbenzene or 1,-1-dimethylethylbenzene were determined from density measurements at 298. 15 K using an Anton Paar DMA 58 vibrating tube densitometer. The excess molar volumes were positive throughout the concentration ranges. The excess molar volumes increase with the size of the hydrocarbon.

Mixtures formed of alkyl acetates with olive oil at 298.15 k

Enthalpies of mixing and heat capacities of the systems formed of alkyl acetates (ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and isobutyl acetate) with olive oil were measured at 298.15 K. The mixing of acetates with the oil was strongly endothermic, and the highest measured enthalpies per mole of mixture were 2000 J mol-1 for ethyl acetate at an acetate mole fraction of 0.6. The heat capacities of the mixtures were calculated too and values were decreasing as the mole fraction of acetate increases and varied from 296 to 3929 J K-1 mol-1.

Construir el hueco para habitar su borrado: Unas notas sobre la poesía de Josep M. Rodríguez

En este articulo se estudia la poesia de Josep M. Rodriguez como indagacion en el misterio de lo real, pero tambien como un modo de ser en la realidad, que condiciona un yo desenfocado , que trata de afi rmarse negandose como acto de existencia pero tambien como acto de lenguaje. La escritura poetica no es, entonces, el modo de plasmar la subjetividad, sino la forma de constatar su ausencia; no es un modo de ser, sino de borrarse. Escribir poesia es una invitacion a la comprension de una realidad fragmentaria.