in this paper, a simplified formulation for compositional reservoir simulator is presented. these types of simulators are used when inter-phase mass transfer depends on phase composition as well as pressure. the procedure for solving compositional model equations is completely described. for equilibrium calculation, property estimation peng robinson equation of state is used. this equation was ...

Modeling of the relationship between the pressure and yield of biomaterials is an essential issue in supercritical fluid extraction. In this paper, neural networks are proposed for modeling of supercritical fluid extraction. First a three-layer neural network with a fast learning algorithm is used, and its performance is compared to a conventional model of the Peng-Robinson equation of state. A...

The peng-Robinson (PR), a cubic equation of state (EoS), is extended to polymers by using a single set of energy (A1, A2, A3) and co-volume (b) parameters per polymer fitted to experimental volume data. Excellent results for the volumetric behavior of the 11 polymer up to 2000 bar pressure are obtained. The EoS is applied to the correlation and prediction of Henry constants in polymer solutions...

In this paper, we introduce and consider the concept of the prox-regularity of a multifunction. We mainly study the metric subregularity of a generalized equation defined by a proximal closed multifunction between two Hilbert spaces. Using proximal analysis techniques, we provide sufficient and/or necessary conditions for such a generalized equation to have the metric subregularity in Hilbert s...

A correlation based on the general form of cubic equations of state has been derived. This equation provides a convenient mathematical form of the Joule-Thomson coefficient in terms of the state variable V and T. The Joule-Thomson coefficient calculated by this correlation has been compared with experimental data. It has been shown that the Redilich-Kwang equation of state is a suitable equ...

We show that a cubic fourfold F that is apolar to a Veronese surface has the property that its variety of power sums V SP (F, 10) is singular along a K3 surface of genus 20 which is the variety of power sums of a sextic curve. This relates constructions of Mukai and Iliev and Ranestad. We also prove that these cubics form a divisor in the moduli space of cubic fourfolds and that this divisor is...

A class of solutions of the low energy string theory in four dimensions is studied. This class admits a geodesic, shear-free null congruence which is non-twisting but in general diverging and the corresponding solutions in Einstein’s theory form the Robinson-Trautman family together with a subset of the Kundt’s class. The Robinson-Trautman conditions are found to be frame invariant in string th...

Gas hydrates attracted worldwide attention due to their potential as huge energy resource in the recent decades. Effective parameters which influence the formation of hydrates are high pressure, low temperature and water presence. HYSYS software is one of the major simulators which are widely used in the chemical and thermodynamic processes. This research was conducted to simulate gas hydrate f...