the aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. thermal efficiency is defined as a function of unknown variables (fluid pressure and vapour ...

A new model for the vapor phase of a pressurized liquid called "the cluster model: which is originally introduced in this work, along with an accurate equation of state for the liquid phase called the LIR, is used to derive an accurate equation for the vapor pressure of liquid as a function of external pressure. The chemical Potential of both phase have been found to be in good agreement wi...

Current Isothermal Titration Calorimetry (ITC) data in the literature have relatively high errors in the measured enthalpies of protein-ligand binding reactions. There is a need for universal validation standards for titration calorimeters. Several inorganic salt co-precipitation and buffer protonation reactions have been suggested as possible enthalpy standards. The performances of several com...

Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and reaction in these mixtures that can profoundly alter material properties and function. We develop a general theoretical framework for quantifying changes in the "high-frequency" relaxation dynamics of mixtures based on classical transition state theory, in conjunction with mathematical statements reg...

During the past year the activities of the Chemical Thermodynamics Data Center and the JANAF Thermochemical Tables project have been combined to obtain an extensive collection of thermodynamic information for many chemical species, including the elements. Currently available are extensive bibliographic collections and data files of heat capacity, enthalpy, vapor pressure, phase transitions, etc...

Heat capacities measured as a function of temperature for Al(115)(+), Al(116)(+), and Al(117)(+) show two well-resolved peaks, at around 450 and 600 K. After being annealed to 523 K (a temperature between the two peaks) or to 773 K (well above both peaks), the high temperature peak remains unchanged but the low temperature peak disappears. After considering the possible explanations, the low te...

Abs t rac t -The persistence of many seemingly metastable mineral assemblages in sediments and soils is commonly attributed to their sluggish transformation to the stable-phase assemblage. Although undoubtedly kinetics plays a major role, this study shows that thermodynamic factors, particularly surface energy, significantly influence the free energy. Enthalpies of formation of boehmite samples...

In this paper, the basic constitutive equations and equations of motion are derived to describe the behavior of thermoelastic porous piezoelectric medium by using Biot’s theory and the theory of generalized thermoelasticity with on relaxation time (Lord-Shulman). The electrical enthalpy density function is derived in the general coordinates. Also, clear definitions for the poroelastic modulus, ...

The aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the Rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. Thermal efficiency is defined as a function of unknown variables (fluid pressure and vap...

This paper presents a model reference adaptive PD control scheme based on RBF neural network for the greenhouse climate control problem. A model of nonlinear conservation laws of enthalpy and matter between numerous system variables affecting the greenhouse climate is used to validate the proposed control scheme. Compared with the conventional adaptive PD control scheme based on RBF neural netw...