Based on Gibbs-Duhem law and using UNIFAC-FV computer algorithm, the activity of polymer component in polymer-solvent systems is determined. The variation of activity of components with concentration at different temperatures are used to find the equilibrium concentration, UCST, and LCST for the systems. Also by generalization of the method, Gel-Liquid equilibrium is studied in some three c...

The influence of pressure variations upon distillation operation does not seem to be well-understood in the open literature, because contradicting statements concerning the importance of pressure control on binary distillation are found. To minimize energy consumption, it is recommended to operate columns at minimum pressure; however, even if column pressure is controlled, instability may still...

Flash point is the most important variable used to characterize fire and explosion hazard of liquids. Herein, partially miscible mixtures are presented within the context of liquid-liquid extraction processes and heterogeneous distillation processes. This paper describes development of a model for predicting the flash point of binary partially miscible mixtures of aqueous-organic system. To con...

Varnish and sludge formation are considered as one of the most common problems in lubrication and hydraulic systems. In order to simulate the condition of sludge formation, base stock lubricant (Group 1 API) has been selected and exposed to heat in a laboratory setup. Sludge formation process accelerated in the laboratory scale and solid liquid equilibrium data were extracted. Then solid-liquid...

the modified nrtl (m-nrtl) model is used to represent the excess gibbs free energy of aqueous (alcohol + electrolyte) solutions. in this work, the m-nrtl model previously developed for representation of vapor-liquid equilibria for (polymer + salt + water) systems has been extended to represent liquid-liquid equilibria of (alcohol + salt + water) systems. the proposed extension is a modified of ...

This paper presents a case study of developing and implementing methods to capture, code and comprehend reciprocal social interactions in a three-dimensional virtual learning environment (3D VLE). The environment, iSocial, is being developed to help youth with autism spectrum disorders (ASD) develop social competencies. The approach to identifying, classifying and coding behavior in the 3D VLE ...

The success of a virtual learning environment (VLE) depends to a considerable extent on student acceptance and use of such an e-learning system. After critically assessing models of technology adoption, including the Technology Acceptance Model (TAM), TAM2, and the Unified Theory of Acceptance and Usage of Technology (UTAUT), we build a conceptual model to explain the differences between indivi...