Equations of State / High Pressure /Phase Equilibrium / Supercritical Extraction / ThermodynamicsThe use (and limitations) of equations of state for collating and predicting liquidlliquid and liquid/dense fluid equilibria is discussed with reference to 15 binary pairs (including some new data for the Carbon dioxide/Hexadecane system at 60°C) and three ternary combinations. It is concluded that the estimation of some of the parameters required for these calculations would be difficult if the solute was a complex substance Ber. Bunsenges. Phys. Chem. 88, 812-820 (1984) -0 Verlag Chemie GmbH, D-6940 Weinheim, 1984. OOO5-9021/84/0909-0812 $ 02.50/0 M. B. King et al.: Prediction of Mutual Solubilities of Heavy Components with Super-critical etc.813 about which little was known apart from its structural formula. -An alternative procedure is to apply activity coefficient expressions of the "regular solution" or UNIFAC type to each phase. Preliminary calculations along these lines are described and the physical basis for applying these methods under the relevant conditions is discussed. The "UNIFAC" approach in particular has been found to be encouraging, though the interaction parameters must be regarded as pressure dependent.

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The thermoelectric effect forms the basis of Peltier cooling that has attracted interest for solid-state refrigeration for more than a century. The dearth of materials level efficiency in converting between heat and electricity has limited widespread applications. With renewed focus on energy technologies in the past three decades, the thermoelectric effect has been intensely explored in new materials using state-of-the-art advances in materials fabrication, characterization techniques, and theory. This article aims to navigate the complex landscape of these studies to identify credible advances, pinpoint continuing problems, and lay out future prospects for both research and applications, with emphasis on electronics cooling.

Equilibrium molecular dynamics (EMD) simulations aiming to investigate the effect of confinement gap thickness on constant volume molar heat capacity (Cv) of the confined liquid in nanoscale have been carried out by simultaneously controlling the density and temperature of the liquid domain. Simplified Lennard-Jones (LJ) molecular model is used to model the system where the liquid is entrapped between two flat solid surfaces separated by a distance varying from 0.585 nm to 27.8 nm. Molar heat capacity of the bulk liquid has been evaluated using fluctuation formula which matches greatly with the NIST data and published literatures. But in case of confined liquid, molar heat capacity is observed to vary significantly with the gap thickness. For a specific range of gap thickness, molar heat capacity of the confined liquid is found higher than that of the bulk. But molar heat capacity of the nanogap confined liquid becomes independent of the gap thickness and approaches to that of the bulk liquid as gap thickness is greater than this specific range (6.14 nm for 100 K temperature of the confined liquid).

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