Search

Phase equilibrium diagrams of fluid phases in ternary systems can have a high complexity. In this work, a strategy and calculation methods for the computation of complete sections of ternary fluid phase equilibrium surfaces is proposed. To illustrate the methodology, we present computed results for the fluid phase equilibrium of an isothermal section for the ternary highly non-ideal system CO2+H2O+2-propanol(IPA), as described by a given model and given set of values of the model parameters. The calculation method is based on the prior identification of (univariant) key points (KPs) of the ternary isotherm. From such KPs, it is possible to build the different equilibrium lines that constitute the ternary isothermal diagram, with the help of a numerical continuation method. The results show a high level of complexity including a number of three-phase loci, critical loci, and ternary critical endpoints, together with a ternary four-phase equilibrium point. Fil: Pisoni, Gerardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Planta Piloto de Ingeniería Química (I). Grupo Vinculado al Plapiqui - Investigación y Desarrollo en Tecnología Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentina. Universidade Estadual de Maringa; Fil: Cismondi Duarte, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Planta Piloto de Ingeniería Química (I). Grupo Vinculado al Plapiqui - Investigación y Desarrollo en Tecnología Química; Argentina Fil: Zabaloy, Marcelo Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentina Fil: Cardozo Filho, Lucio. Universidade Estadual de Maringa; Brasil

Lignocellulosic nanostructures, mainly cellulose and lignin based materials, have recently attracted much attention due to their renewable nature, wide variety of source materials available throughout the world, low cost and density, high surface functionality and reactivity. The exceptional mechanical strength, together with high aspect ratio and large surface area, enable these nanomaterials to reinforce a wide variety of polymers even at very low filler loadings. Furthermore, nanocomposite approach has emerged in the last two decades as an efficient strategy to upgrade the structural and functional properties of natural and/or synthetic polymers. The combination of bioresorbable and sustainable polymers with bio-based nanostructures opened new perspectives in the self-assembly of nanomaterials for different applications with tuneable mechanical, thermal and degradative properties. In the present paper, the effect of introduction of lignocellulosic reinforcement phases (cellulosic and lignin based nanostructures), on structural and functional properties of several thermoplastic polymer matrices was investigated at the nanoscale level. Both solvent casting and melt compounding were considered as processing techniques for the proposed nanocomposite formulations. The role of cellulose and lignin based nanostructures, such as their synergic action when embedded in a polymer matrix, were analysed (taking into account the required functionality of the systems in the appropriate final applications) and reported in terms of morphological, optical, thermal, chemical, mechanical, barrier and degradative performance.

Efavirenz (EFZ) is one of the most used drugs in the treatment of AIDS and is the first antiretroviral choice. However, since it has low solubility, it does not exhibit suitable bioavailability, which interferes with its therapeutic action and is classified as a class II drug according Biopharmaceutical Classification System (low solubility and high permeability). Among several drug delivery systems, the multicomponent systems with cyclodextrins and hydrophilic polymers are a promising alternative for increasing the aqueous solubility of the drug. The present study aimed to develop and characterize in a ternary system of EFZ, MβCD and PVP K30. The results showed that the solid ternary system provided a large increase in the dissolution rate which was greater than 80% and was characterized by DSC, TG, XRD, FT-IR and SEM. The use of the ternary system (EFZ, MβCD and PVP K30 1%) proved to be a viable, effective and safe delivery of the drug. The addition of the hydrophilic polymer appeared to be suitable for the development of a solid oral pharmaceutical product, with possible industrial scale-up and with low concentration of CDs (cyclodextrins).

Exploiting the mechanisms responsible for the exceptional properties of aluminum based nitride coatings, we apply ab initio calculations to develop a recipe for designing functional thin film materials based on ternary diborides. The combination of binary diborides, preferring different structure types, results in supersaturated metastable ternary systems with potential for phase transformation induced effects. For the exemplary cases of MxW1 − xB2 (with M = Al, Ti, V) we show by detailed ab initio calculations that the respective ternary solid solutions are likely to be experimentally accessible by modern depositions techniques., Highlights • Interplay and competition of two different structural modifications in ternary borides • Stability of ternary boride systems with respect to spinodal decomposition • Enormous potential of ternary borides for thin film applications

In this work the usefulness of qualitatively studying and drawing three-dimensional temperature–composition diagrams for ternary systems is pointed out to understand and interpret the particular behavior of the liquid–vapour equilibrium of non-ideal ternary systems. Several examples have been used in order to highlight the interest and the possibilities of this tool, which should be an interesting support not only for lecturers, but also for researchers interested in experimental equilibrium data determination. The authors are grateful to the University of Alicante for the funding of the “Grupo de Innovación Tecnológica-Educativa (GITE) de Ingeniería Química”, where this work has been carried out.

Prediction of bulk metallic glass (BMG) forming compositions has always been a challenge due to thermodynamic and kinetic constraints. In the present investigation, a parameter based on the enthalpy of chemical mixing (?Hchem) and the mismatch entropy (?S?/ kB) has been used to correlate with glass forming ability in some Zr based BMGs. The new thermodynamic parameter, PHS = ?H chem � ?S?/kB, is found to have strong correlation with glass forming ability in the configurational entropy (?Sconfig/R) range of 0.9-1.0. PHS has been calculated for compositions in Zr-Cu-Ag, Zr-Cu-Al, Zr-Cu-Ti and Zr-Cu-Ga ternary systems. It is observed that in all the systems studied, the best BMG composition (highest critical diameter (Zc) of glass formation) is the one that corresponds to the highest negative PHS value. Present approach using PHS could be road map to design new BMG forming compositions. � 2011 Elsevier B.V. All rights reserved.

In the present work the structure and morphology of the phases of nanocomposites formed in rapidly solidified Al–Fe alloys were investigated in details using analytical transmission electron microscopy and X-ray diffraction. Nanoquasicrystalline phases, amorphous phase and intermetallics like Al 5 Fe 2 , Al 13 F 4 coexisted with α-Al in nanocomposites of the melt spun alloys. It was seen that the Fe supersaturation in α-Al diminished with the increase in Fe content and wheel speed indicating the dominant role of the thermodynamic driving force in the precipitation of Fe-rich phases. Nanoquasicrystalline phases were observed for the first time in the dilute Al alloys like Al–2.5Fe and Al–5Fe as confirmed by high resolution TEM. High hardness (3.57 GPa) was measured in nanocomposite of Al–10Fe alloy, which was attributed to synergistic effect of solid solution strengthening due to high solute content (9.17 at.% Fe), dispersion strengthening by high volume fraction of nanoquasicrystalline phase; and Hall–Petch strengthening from finer cell size (20–30 nm) of α-Al matrix.

The effect of tube diameter on two-phase frictional pressure drop was investigated in circular tubes with inner diameters of 0.6, 1.2, 1.7, 2.6 and 3.4. mm using air and water. The gas and liquid superficial velocity ranges were 0.01-50. m/s and 0.01-3. m/s, respectively. The gas and liquid flow rates were measured and the two-phase flow pattern images were recorded using high-speed CMOS camera. Unique flow patterns were observed for smaller tube diameters. Pressure drop was measured and compared with various existing models such as homogeneous model and Lockhart-Martinelli model. It appears that the dominant effect of surface tension shrinking the flow stratification in the annular regime is important. It was found that existing models are inadequate in predicting the pressure drop for all the flow regimes visualized. Based on the analysis of present experimental frictional pressure drop data a correlation is proposed for predicting Chisholm parameter " C" in slug annular flow pattern. For all other flow regimes Chisholm's original correlation appears to be adequate except the bubbly flow regime where homogeneous model works well. The modification results in overall mean deviation of pressure drop within 25% for all tube diameters considered. This approach of flow regime based modification of liquid gas interaction parameter appears to be the key to pressure drop prediction in narrow tubes. � 2010 Elsevier Inc.

An extension of Barker's method to ternary systems is briefly outlined. Expressions for the standard deviations of the excess molar Gibbs free energy and the equilibrium pressure as functions of composition are obtained. These expressions are applied to accurate experimental data for the cryogenic (liquid) mixture CH3F+N2O+Xe recently measured in our laboratory. http://www.sciencedirect.com/science/article/B6TG2-3VGSGDR-4/1/e3c29abb1f0602ee677ab2a9887b8eee