Calculation of the thermodynamic functions using a mean field model for the fluid-solid transition in nitrogen

Temperature and pressure dependence of the thermodynamic quantities are calculated using the Landau phenomenological model for the first order fluid-solid transition in nitrogen. This calculation is performed by fitting the phase line equation as derived from the mean field model to the observed T-P phase diagram of the fluid-solid transition in N2 from the literature. Our calculations show that the order parameter and the inverse susceptibility decrease whereas the entropy, heat capacity, thermal expansion and isothermal compressibility exhibit anomalous behavior as the melting point is approached in nitrogen. This indicates that the first order fluid-solid transition in N2 can be described by the mean field model studied here.
Revue Roumaine de Chimie


Orbey, H.; Orbey, N. (Informa UK Limited, 1989-3)
A data reduction technique is introduced for the evaluation of second virial coefficients of gases at subcritical temperatures. The method makes use of the vapor-liquid equilibrium data, i.e., temperature, saturation pressure, liquid and vapor molar volumes and can be used to obtain second virial coefficients of a wide variety of fluids including polar, associating and quantum gases. The calculated second virial coefficients are in good agreement with their counterparts from literature, which are obtained f...
Yurtseven, Hasan Hamit (Romanian Academy - Revue Roumaine De Chimie, 2019-03-01)
The temperature-pressure (T-P) phase diagrams are calculated using the mean field models for the solid-fluid (first order) and, the solid-solid transitions of the delta-delta(loc) (second order) and delta(loc)-epsilon (first order) in nitrogen. By expanding the free energy in terms of the order parameters, the phase line equations are derived and they are fitted to the experimental data from the literature for this molecular crystal. For the fitting procedure, the coefficients in the free energy expansion a...
Calculation of the specific heat using the Raman frequency shifts for the solid I-II transition in benzene
Yurtseven, Hasan Hamit (Elsevier BV, 2015-06-15)
The specific heat C-p is calculated as a function of temperature using the observed Raman frequency shifts of the six lattice modes at constant pressures of 0 and 0.1 GPa for the solid I-II transition in benzene. This calculation is performed using the volume data through the mode Grfineisen parameter of each lattice mode which we determined as functions of temperature and pressure. The specific heat C-p is also calculated as a function of pressure at room temperature using the Raman frequency shifts of tho...
Calculation of the specific heat from the Raman frequency shifts close to the tricritical and second order phase transitions in NH4Cl
Kaya, D.; Yurtseven, Hasan Hamit (Elsevier BV, 2007-05-01)
This study gives our calculation for the specific heat using our Raman frequency shifts of the v(5) (174 cm(-1)) mode close to the tricritical (P = 1.6 kbar) and second order (P = 2.8 kbar) phase transitions in NH4Cl. For this calculation we use as the values of the critical exponent for the specific heat, a = 0.11 (T < T-c and T > T-c) for the tricritical (T-c = 257.17 K), and a = 0.18 (T < T-c), a = 0.64 (T > T-c) for the second order (T-c = 268 K) phase transitions, which we deduce from our analysis of t...
Experimental investigation of drag reduction effects of polymer additives on turbulent pipe flow using ultrasound Doppler velocimetry
Zeybek Vural, Serife; Bayram, Göknur; Uludağ, Yusuf (The Scientific and Technological Research Council of Turkey, 2014-01-01)
Drag reduction in fully developed turbulent pipe flow with 4 concentrations (200 to 500 wppm or mg/kg) of low molecular weight sodium carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. Maximum drag reduction achieved was 22% using 500 wppm CMC solution. To observe the impact of the presence of CMC on the flow, ultrasound Doppler velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. Expe...
Citation Formats
Ö. AKAY and H. H. Yurtseven, “Calculation of the thermodynamic functions using a mean field model for the fluid-solid transition in nitrogen,” Revue Roumaine de Chimie, pp. 425–432, 2020, Accessed: 00, 2020. [Online]. Available: