In this article, a simple and no cost method, which is based on Archimedes’ principle and moment of force and which does not require measurement of mass and volume of the liquid, is described for the determination of the density of liquids. The experimental set up for this purpose is very simple. A meter scale is hung by a string from a rigid support at center point. A solid substance of unknow...

We calculate third- and fifth-order Raman spectra of simple atoms interacting through a soft-core potential by means of molecular-dynamics (MD) simulations. The total polarizability of molecules is treated by the dipole-induced dipole model. Two- and three-body correlation functions of the polarizability at various temperatures are evaluated from equilibrium MD simulations based on a stability ...

The classical fluid dynamics boundary condition of no slip suggests that variation in the wettability of a solid should not affect the flow of an adjacent liquid. However, experiments and molecular dynamics simulations indicate that this is not the case. In this paper we show how flow over a solid substrate with variations of wettability can be described in a continuum framework using the inter...

In the previous multi-solid models,φ approach is used for the calculation of fugacity in the liquid phase. For the first time, in the proposed multi-solid thermodynamic model,γ approach has been used for calculation of fugacity in the liquid mixture. Therefore, some activity coefficient models have been studied that the results show that the predictive Wilson model is more appropriate than othe...

A density-of-states Monte Carlo method is proposed for simulations of solid-liquid phase equilibria. A modified Wang-Landau density-of-states sampling approach is used to perform a random walk in regions of potential energy and volume relevant to solid-liquid equilibrium. The method provides a direct estimate of the relative density of states [Omega(U,V)] and thus the relative free energy withi...

We propose a theory to describe time-dependent solvation structure near solid-liquid interface. Recently, we have developed two-dimensional-reference interaction site model to describe solvation structure near solid-liquid interface at the equilibrium state. In the present study, the theory is extended to treat dynamical aspect of the solvation; site-site Smoluchowski-Vlasov equation and surrog...

A major computational code called CERV was developed to determine complex equilibrium compositions of a nonideal mixture of numerous imperfect gases and compressible liquid and solid species with phase transitions for closed-vessel applications. This code minimizes Gibbs energy using reaction variables, in contrast to other major codes like BRL-Blake, BRCBagheera and NASA-CEA that use compositi...

The paper concern is determination of eight pesticides in food products samples. The target compounds are: Lindane, Heptachlor, Aldrin, o,p-DDE, Dieldrin, Endrin, p,p’-DDT, and Methoxychlor. The compounds quantities were performed from chromatographic area obtained in full scan GC/MS mode after baseline separation and by comparation with surrogate internal standard area (Diphenylamine). The sam...

Saltwater (S), with the same ionic strength of seawater, was employed as solvent to extract polyphenols from seaweeds. Aqueous extracts were chemically characterized by means total (TPC), carbohydrates (CHOS) and uronic acids (UA) content antioxidant capacities (DPPH, ABTS FRAP). S-extracts showed lower TPC than those obtained distilled water (D) using two different extraction methods, conventi...

It is often difficult to determine the solid-liquid transition by conventional simulation techniques because of the computational challenges posed by two dense phases. Hansen and Verlet [Han69] reported the first molecular simulation results for solid-liquid phase coexistence. They used a thermodynamic integration algorithm that involves the accurate evaluation of free energies. The widely used...