The interfacial tension (I.F.T.) of petroleum reservoir fluids are commonly predicted by either the parachor method or the scaling law. Both methods have been evaluated against literature data of binary systems. The predictive capability of the methods have been improved by a simple modification of the original correlations. The superiority of modified methods have been demonstrated by comparing predicted results with experimental I.F.T. values for two gas condensate fluids at wide ranges of pressure and temperature.

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Growth of InGaN, having high Indium composition without compromising crystal quality has always been a great challenge to obtain efficient optical devices. In this work, we extensively study the impact of non-radiative defects on optical response of the plasma assisted molecular beam epitaxy (PA-MBE) grown InGaN nanowires, emitting in the higher wavelength regime ( λ > 520 nm). Our analysis focuses into the effect of defect saturation on the optical output, manifested by photoluminescence (PL) spectroscopy. Defect saturation has not so far been thoroughly investigated in InGaN based systems at such a high wavelength, where defects play a key role in restraining efficient optical performance. We argue that with saturation of defect states by photo-generated carriers, the advantages of carrier localization can be employed to enhance the optical output. Carrier localization arises because of Indium phase segregation, which is confirmed from wide PL spectrum and analysis from transmission electron microscopy (TEM). A theoretical model has been proposed and solved using coupled differential rate equations in steady state to undertake different phenomena, occurred during PL measurements. Analysis of the model helps us understand the impact of non-radiative defects on PL response and identifying the origin of enhanced radiative recombination.

The rapidly increasing interest in nanowires (NWs) of GaN and associated III-Nitrides for (opto-)­electronic applications demands immediate address of the technological challenges associated with NW-based device processing. Toward this end, we demonstrate in this work an approach to suppress the thermal decomposition of GaN NWs, which also serves to passivate the surface states. Both of these effects are known to be significant challenges in the development of GaN-NW-based devices. The approach entails AlN capping of the as-grown GaN NWs, in the same molecular beam epitaxy growth step. We show that the epitaxial AlN crest that grows on the top facet of the NW arrests thermal decomposition, while the AlN shell on the sidewalls (together with the crest) protects the NW surface from the generation of oxygen-induced surface states. This simple approach can be used for the development of GaN-NW-based devices.