calculate some thermodynamic properties of molten polymers including specific volume and isothermal compressibility (s.m. hoseini, physical chemistry & electrochemistry, 2 (2014) 56-65). this work extended that eos to predict the volumetric properties of some molten ethylene copolymers including ethylene/1-octene, ethylene/1-butene (xethylene equal to 0.8543 and 0.563), ethylene/propene. the ab...

we have investigated the electronic structure and thermodynamic properties of supercell of the
-al2o3 by first-principles calculation in framework of density functional theory (dft) and full potential linearized augmented plane wave (fp-lapw) with generalized gradient approximation (gga) and by quasi-harmonic debye model. our calculated value for direct band gap of α-al2o3 is 7.2 ev which is v...

Original scientific paper The paper presents the possibility of electricity generation at the pressure reduction stations (PRS) in the conventional system of natural gas transmission and distribution. The main deficiency of the conventional system is its thermodynamic irreversibility, i.e. the loss of potential work that could be generated while reducing the gas pressure. Within the first part ...

heat recuperation is often used to improve the overall cycle efficiency of gas turbines. however, generally in small- scale gas turbines, it has a negative effect on turbine inlet temperature, pressure ratio and pressure drops, and thus decreases the overall cycle efficiency. in this paper, a thermodynamic model is performed to evaluate recovered heat as a function of heat exchanger effectivene...

In this paper, the Hartree-Fock method has been formulated to investigate some of the ground state properties of quasi-one-dimensional interacting electron gas in the presence of the magnetic field. The bare coulomb interaction between electrons has been assumed. For this system, we have also computed some of its thermodynamic and magnetic properties such as the energy, pressure, incompressibil...

Recent years have seen a tremendous progress in the microscopic theoretical treatment of surfaces and processes on surfaces. While some decades ago a phenomenological thermodynamic approach was dominant, a variety of surface properties can now be described from first principles, i.e. without invoking any empirical parameters. Consequently, the field of theoretical surface science is no longer l...

We have investigated the electronic structure and thermodynamic properties of supercell of the -Al2O3 by first-principles calculation in framework of density functional theory (DFT) and full potential linearized augmented plane wave (FP-LAPW) with generalized gradient approximation (GGA) and by quasi-harmonic Debye model. Our calculated value for direct band gap of α-Al2O3 is 7.2 eV which i...

in this paper, a new combined power and refrigeration cycle is proposed, which combines the rankin power cycle and the ejector refrigeration cycle. this combined cycle produces both power output and refrigeration output simultaneously. this cycle is driven by the flue gas of gas turbines, industrial waste heats, solar energy and geothermal energy. an exergy analysis is performed to guide the th...