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Experimental and predicted excess molar volumes of the ternary system.

Tert-butylmethylether+1-propanol+heptane at 298.15 K

Journal of Thermal Analysis and Calorimetry
Authors: M. M. Mato, S. M. Cebreiro, P. V. Verdes, A. V. Pallas, J. L. Legido, and M. I. Paz Andrade

Summary Experimental excess molar volumes for the ternary system x 1MTBE+x 21-propanol+(1-x 1-x 2) heptane and the three involved binary mixtures have been determined at 298.15 K and atmospheric pressure. Excess molar volumes were determined from the densities of the pure liquids and mixtures, using a DMA 4500 Anton Paar densimeter. The ternary mixture shows maximum values around the binary mixture MTBE+heptane and minimum values for the mixture MTBE+propanol. The ternary contribution to the excess molar volume is negative, with the exception of a range located around the rich compositions of 1-propanol. Several empirical equations predicting ternary mixture properties from experimental binary mixtures have been applied.

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Summary Experimental densities for the ternary mixture x 1MTBE+x 21-propanol+(1-x 1-x 2)decane and the binary mixtures xMTBE +(1-x)1-propanol and x1-propanol+(1-x)decane have been measured at 298.15 K and atmospheric pressure, using a DMA 4500 Anton Paar densimeter. Excess molar volumes were determined from the densities of the pure liquids and mixtures. Attending to the symmetry of the studied mixtures, suitable fitting equations have been used in order to correlate adequately the experimental data. For the ternary mixture, experimental data were also used to test several empirical expressions for estimating ternary properties from experimental binary results.

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Abstract  

Thermal analysis has been used to evaluate the stability, glass transition, and water retention of Nafion based polymer–ceramic electrolytes. These electrolytes are envisioned as promising replacement of Nafion in fuel cells operating above 100 °C. The polymeric matrix prepared by casting exhibits lower crystallinity than the extruded Nafion, a feature that affects the water absorption properties. The addition of titania-based nanotubes and nanoparticles to the polymer has enhanced the water retention at high temperatures (~130 °C) and the glass transition temperature, respectively. Such results are important for the design of composite electrolytes for the operation of fuel cells at high temperatures.

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Summary Densities at 298.15 K have been measured for the ternary mixture methyl tert-butyl ether (MTBE)+1-pentanol+heptane and for the involved binary mixtures. Excess molar volumes were calculated from densities. Attending to the symmetry of experimental excess molar volumes, suitable fitting equations have been used in order to correlate adequately the experimental data. Several empirical expressions for estimating ternary properties from experimental binary results.

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Journal of Thermal Analysis and Calorimetry
Authors: L. Cides da Silva, G. Araújo, N. Segismundo, E. Moscardini, L. Mercuri, I. Cosentino, M. Fantini, and J. Matos

Abstract  

The aim of this study was to use DSC and X-ray diffraction measurements to determine the pore size and pore wall thickness of highly ordered SBA-15 materials. The DSC curves showed two endothermic events during the heating cycle. These events were due to the presence of water inside and outside of mesopores. The results of pore radius, wall thickness and pore volume measurements were in good agreement with the results obtained by nitrogen adsorption measurement, XRD and transmission electron microscopy.

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Abstract

A microcalorimetric method was applied to study microbial soil activity of ornamental flower (Dahlia pinnata) plantations when irrigated with potable water and wastewaters. The samples were irrigated with potable water PW sample (reference) and treated wastewaters from Municipal Wastewater Treatment Station of Asa Norte in Brasilia City (Brazil). Three different water treatments were applied to irrigate soil samples, named TW1, TW2, and TW3 samples. The increase of the microbial soil activity observed in TW1 sample must have occurred because of the high amount of organic waste dissolved in wastewater used for irrigation. This rise indicates that the present treated wastewater can affect natural life cycle. However, only a low alteration in microbial soil activity was observed in the TW2 and TW3 samples, which suggests that these wastewater treatments can be normally used to irrigate soils without bringing environmental consequences, once they offer a great opportunity to upgrade and protect the environment.

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