using gaussian 03, software the thermodynamic functions such as gibbs free energy, g, enthalpy, h, and entropy, s, of alanine and valine amino acids were theoretically studied at different solvents. first, the density functional theory (b3lyp) level with 3-21g, 6-31g and 6-31+g basis sets were employed to optimization of isolated alanine and valine amino acids in the gas phase. moreover, vib...

Heat pumps offer economical alternatives of recovering heat from different sources for use in various industrial, commercial and residential applications. In this study, singlestage air-source vapor compression heat pump system has been optimized using a genetic algorithm (GA) and fuzzy logic (FL). The necessary thermodynamic properties for optimization were calculated by FL. Thermodynamic prop...

Lubricating greases are special lubricants with a wide range of application. The tribologically stressed grease is used as tribological system and finally modeled as an open thermodynamic system. This study investigated the phenomenon of self-optimization and applied to the process of shearing a grease. The conditions for self-optimization and the consequences of created dissipative structures ...

This paper addresses dynamic optimization of a large-scale natural gas processing plant through the formulation of rigorous unit dynamic models. The resulting differential-algebraic equation (DAE) optimization problem is solved with an advanced simultaneous strategy that transforms the original problem into a nonlinear program. Emphasis has been given to detailed thermodynamic and solubility ca...

A method is presented for assigning protonation states and hydrogen atom geometry to macromolecular structures. Tautomer and ionization state (including metal ligation) are taken into account during a large scale free energy optimization. This discrete optimization is performed with a Unary Quadratic Optimization procedure. The thermodynamic theory and the results of several computational valid...

In this paper multi-objective genetic algorithms are employed for Pareto approach optimization of ideal Turboshaft engines. In the multi-objective optimization a number of conflicting objective functions are to be optimized simultaneously. The important objective functions that have been considered for optimization are specific thrust 0 ( / ) & F m , specific fuel consumption ( P S ), output sh...

performance optimization of a single-effect lithium bromide water absorption refrigerationsystem is the subject of this paper. first, the thermodynamic model of the system wasderived based on thefirst and second law analysis of an absorption refrigeration cycle with libr-water as the working fluid pair.then, the effects of different design parameters such as the generator inlet hot water temper...

This paper deals with a multi-objective optimization of a novel micro solar driven combined power and ejector refrigeration system (CPER). The system combines an organic Rankine cycle (ORC) with an ejector refrigeration cycle to generate electricity and cold capacity simultaneously. Major thermodynamic parameters, namely turbine inlet temperature, turbine inlet pressure, turbine back pressure, ...