The constant pressure-temperature (P− T ) flash plays an important role in the modelling of fluid-phase behaviour, and its solution is especially challenging for equations of state in which the volume is expressed as an implicit function of the pressure. We explore the relative merits of solving the P− T flash in two ensembles: mole numbers, pressure and temperature, in which each free-energy e...

Physiologists and biochemists frequently ignore the importance of adjusting equilibrium constants to the ionic conditions of the cell prior to calculating a number of bioenergetic and kinetic parameters. The present study examines the effect of pH and free magnesium levels (free [Mg2+]) on the apparent equilibrium constants (K') of creatine kinase (ATP: creatine N-phosphotransferase; EC 2.7.3.2...

the armaticity of 5 methylcytosine tautomers in the gas phase has been studied and the chemical structures of related tautomers are investigated . the electronic energy, enthalpy and free energy of each tautomer are also estimated at the b3lyp/6-31 g* // b3lyp/6-31 g* and mp2 / 6-31 g* // mp2 / 6-31 g* levels

Geometric programming is a mathematical technique, which has been developed for nonlinear optimization problems. This technique is based on the dual program with linear constraints. Determination of species concentrations in chemical equilibrium conditions is one of its applications in chemistry and chemical engineering fields. In this paper, the principles of geometric programming and its comp...

Let h be a finite dimensional complex Hilbert space, b(h)+ be the set of all positive semi-definite operators on h and Phi is a (not necessarily linear) unital map of B(H) + preserving the Entropy-Gibbs transformation. Then there exists either a unitary or an anti-unitary operator U on H such that Phi(A) = UAU* for any B(H) +. Thermodynamics, a branch of physics that is concerned with the study...

A cluster density matrix is introduced in the form suitable for the selfconsistent calculation of relevant thermodynamic averages for the Ising model with spin S = 1/2. On this basis, derivation of the Gibbs free-energy for the effective field theory of Honmura and Kaneyoshi is presented.

Measurements of the surface tensions, densities and viscosities of aqueous solutions of Triton X-100 (TX-100) and rhamnolipid (RL) mixtures, at constant concentration of RL or TX-100, were carried out. The measured values of the surface tension were compared to those determined using different theoretical models and on the basis of the surface tension of aqueous solutions of individual surfacta...

The sign preference of hydrogen bonded aqueous ionic clusters X+/-(H(2)O)(i) (n =1-5, X = F; Cl; Br) has been investigated using the Density Functional Theory and ab initio MP2 method. The present study indicates the anomalously large difference in formation free energies between cations and anions of identical chemical composition. The effect of vibrational anharmonicity on stepwise Gibbs free...

Tree substitution grammars (TSGs) offer many advantages over context-free grammars (CFGs), but are hard to learn. Past approaches have resorted to heuristics. In this paper, we learn a TSG using Gibbs sampling with a nonparametric prior to control subtree size. The learned grammars perform significantly better than heuristically extracted ones on parsing accuracy.