We present an extensive integral equation study of a simple point charge model water for variety thermodynamic states ranging from the vapor phase to undercooled liquid. The calculations are carried out in molecular reference-hypernetted chain approximation and results compared with dynamics simulations. Use hard sphere fluid as reference system provide input bridge function leads relatively good thermodynamics. However, at low temperatures computed microscopic structure shows deficiencies...

We study the demixing transition of mixtures equal size hard spheres and dipolar using computer simulation integral equation theories. Calculations are carried out at constant pressure, it is found that there a strong correlation between total density composition. The critical temperature to increase with pressure. mole fraction component on contrary decreases as pressure augmented. These qualitative trends reproduced by theoretical approaches other hand overestimate far value temperature....

In this paper, an XML-based framework, known as RELATED, is used to build a remote lab for providing experience of control engineering on servo motor using components distributed across the Internet. This new approach allows different groups share their hardware and software resources facilitate creation networks virtual/remote laboratories.

The Tennessee Eastman process is a typical industrial that consists of five main units: two-phase reactor where an exothermic reaction occurs, separator, stripper, compressor, and mixer. This nonlinear open-loop unstable has been used in many studies as case study for plant-wide control, statistical monitoring, sensor fault detection, identification data-driven network models. There are implementations this with different levels detail, but there no implementation developed object-oriented...

A novel approach to the implementation of interactive virtual-labs is proposed. The virtual-lab completely described in Modelica language and translated using Dymola. To achieve this goal, a systematic methodology transform any model into formulation suitable for simulation has been developed. In addition, VirtualLabBuilder library programmed. This contains set models visual elements (i.e. containers, animated geometric shapes controls) that allows easy creation view model-to-user interface).

Abstract The use of the VirtualLabBuilder Modelica library and Dymola modeling environment facilitates implementation virtual‐labs with elaborated user interfaces, based on large complex models. This methodology is applied to develop an industrial boiler virtual‐lab for process control education. freely available at www.euclides.dia.uned.es . © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 36–45, 2013

We have studied two choices of semiphenomenological closures for the Ornstein–Zernike equation, both a monoatomic Lennard-Jones fluid and dipolar homonuclear hard diatomic fluid. One was originally proposed by Verlet hard-sphere systems, which is known to yield good results. A second closure us in frame reference hypernetted chain (RHNC) theory. described systems this means Verlet’s approximation its recent extension nonspherical particles. This approach, we denote RHNC-VM (Verlet’s...

Here, two software tools are presented that facilitate virtual lab implementation: Interactive and Rand Model Designer. is a free Modelica library that's used in combination with the Dymola modeling environment. Designer supports Vision Language, an object-oriented language based on Unified Modeling Language (UML).

A recently proposed reference hypernetted-chain equation based on a semiphenomenological bridge function due to Verlet is reformulated for atomic and molecular Lennard-Jones liquids. In this new approximation we treat the size of reference-system hard particles as density temperature through functional relationship presented herein. The theory yields excellent results structure thermodynamics liquids over wide range quite satisfactory homonuclear diatomics.

Structural, thermodynamic, and dielectric properties of a dipolar fluid confined in charged random matrix are studied by means grand canonical Monte Carlo simulation replica Ornstein–Zernike integral equations the hypernetted chain approximation. The is modeled system hard spheres. Two topologies considered: frozen restricted primitive model sphere with randomly distributed negative positive charges. Both models lead to similar results most cases, significant deviations from behavior...

This paper deals with the use of interactive computer simulation and animation environments in a virtual lab which illustrates real-world applications fundamental control principles. The goals can be summarized as follows: a) provide students motivating introduction to practice engineering b) Show, using simple challenging example - magnetic levitation system, many features multivariable possible. c) Integrate skills principles from throughout curriculum solve practical problems. d)...

We use two molecular integral equation approximations to compute the thermodynamic properties and microscopic structure of liquids composed planar molecules with C2v symmetry, namely SO2 H2S. These couple exact Ornstein–Zernike hypernetted chain (HNC) reference-hypernetted (RHNC) closures. The theoretical results obtained for various states agree remarkably well dynamics calculations. In particular, atom-atom distribution functions are very reproduced. find that RHNC approximation a...

Liquid hydrogen chloride is modeled by a system of heteronuclear two-center Lennard-Jones particles with embedded point dipoles and quadrupoles. The effect molecular polarizability incorporated via an effective dipole approximation. study performed Monte Carlo reaction field simulation hypernetted chain reference integral equations. Our results yield dielectric properties in excellent agreement experimental data for liquid HCl. As the equation approach, we have experimented empirical choice...

The extension of the Barker–Henderson (BH) theory to diatomic potentials is examined by comparison predicted thermodynamic properties with ‘‘exact’’ MC results. Two choices potential separation have been considered; corresponding BH scheme and that Weeks–Chandler–Andersen (WCA). Attention has paid effect usual approximations exact hard reference system (equation state pair correlation functions) convergence rate expansion. Conclusions can also be drawn for WCA-blip function these systems. It...

We present a novel approach for the theoretical determination of atomic structure factors (or site–site distribution functions) based on calculation molecular pair function by integral equations (reference hypernetted chain approximation). The results are compared with experimental and computer simulation homonuclear diatomic fluids (N2, Cl2 Br2) which modeled means two center Lennard-Jones potentials. proposed method leads to surprisingly good agreement data, within obvious limitations that...

The microporous structure of pillared interlayered clays is determined by their interlayer separation and the distribution pillars that separate layers. provide stability to these quasi-two-dimensional high surface area materials. In this work we present a topological analysis available accessible volumes within various simple models clays. Each model characterized pillars. Both fully ordered structures disordered pillar distributions with either attractive or repulsive interpillar...

Virtual labs are valuable educational resources in control education, and widely used the process industry as tools for operator training decision aid. In these application domains, virtual typically rely on interactive simulation of large-scale hybrid-DAE models with components different engineering whose description can be greatly simplified by use Modelica language. Existing free commercial libraries domains to describe models. The Interactive library facilitates developing based models,...

The hypernetted chain and reference integral equations are solved for quadrupolar two-center Lennard-Jones fluids the computed fluid structure thermodynamics contrasted with computer simulation. A bridge function is determined through an empirical modification of Verlet’s approximation. resulting equation leads to good agreement simulation data. On contrary, bare approximation performs poorly, in particular as far state concerned, which a well-known drawback this closure when short ranged...

The aim of this paper is to explore the possibilities a novel molecular integral equation approach produce information on atom–atom microscopic structure fluids via multidimensional integration pair distribution function. In particular, factors for hydrogen halides (HCl and HI) are computed from heteronuclear modeled by two-center Lennard-Jones potential with without multipole terms. Theoretical results compared both experimental partial computer simulation results. Theory agree remarkably...

We have performed extensive Monte Carlo (MC) simulations to evaluate structural and thermodynamic properties of heteronuclear two-centre Lennard-Jones fluids. Computations been carried out for two uncharged molecular models which roughly describe liquid HCl HBr. These are used as test benchmarks a reference hypernetted chain approximation (RHNC-VM), is the natural extension fluids previously developed approach fairly successful in context homonuclear diatomic The proposed theoretical leads...