Critical behaviour of the specific heat and the thermal expansion close to the melting point in ammonia solid III

A linear correlation between the specific heat C(P) and the thermal expansion alpha(p) is established here for constant temperatures close to the melting pressure in ammonia solid III. For this correlation, the experimental data for the isothermal compressibility kappa(T) is analysed according to a power-law formula with the critical exponent gamma and, the C(P) and alpha(p) are calculated as a function of pressure near the melting point in ammonia solid III.


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...
Thermal behaviour of some metal complexes of N,N-diethyl-N'-benzoyl thiourea
Merdivan, M; Aygün, Rüveyde Sezer; Kulcu, N (Springer Science and Business Media LLC, 1997-06-01)
The thermal behaviour of the complexes of N,N-diethyl-N'-benzoylthiourea (DEBT) with NI(II), Cu(II), Pt(II), Pd(II) and Ru(III) was studied using differential thermal analysis (DTA) and thermogravimetry (TG). These complexes undergo only a pyrolytic decomposition process. A gas chromatography-mass spectrometry combined system was used for the verification of the first decomposition product and X-ray diffraction method for the characterization of the final products of pyrolysis.
Catalytic partial oxidation of propylene on metal surfaces by means of quantum chemical methods
Kızılkaya, Ali Can; Önal, Işık; Department of Chemical Engineering (2010)
Direct, gas phase propylene epoxidation reactions are carried out on model slabs representing Ru-Cu(111) bimetallic and Cu(111) metallic catalyst surfaces with periodic Density Functional Theory (DFT) calculations. Ru-Cu(111) surface is modelled as a Cu(111) monolayer totally covering the surface of Ru(0001) surface underneath. The catalytic activity is evaluated following the generally accepted oxametallacycle mechanism. It is shown that the Ru-Cu(111) surface has a lower energy barrier (0.48 eV) for the s...
Kinetic analysis of DSC and thermogravimetric data on combustion of lignite
Kök, Mustafa Verşan (Springer Science and Business Media LLC, 1996-06-01)
Thermal analysis increasingly being used to obtain kinetic data relating to sample decomposition. This work involves a comparative study of several methods used to analyse DSC and TG/DTG data obtained on the oxidation of Beypazari lignite. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. For this study, the ratio method was regarded as the preferred method, because it permits the estim...
Effect of Gas Diffusion Layer Characteristics and Addition of Pore-Forming Agents on the Performance of Polymer Electrolyte Membrane Fuel Cells
Senguel, Erce; Erkan, Serdar; Eroğlu, İnci; BAÇ, NURCAN (Informa UK Limited, 2009-01-01)
The performance of five layer membrane electrode assemblies having different characteristics of gas diffusion layers was determined at 70 degrees C cell temperature and ambient pressure. The maximum power density at 0.6 V was 0.36 W/cm(2) for the membrane electrode assembly prepared with the gas diffusion layer having minimum thickness (SGL BC 30 type). On the other hand, the maximum power density at 0.5 V was 0.44 W/cm(2) for the membrane electrode assembly prepared with SGL BC 34 type gas diffusion layer....
Citation Formats
H. H. Yurtseven, “Critical behaviour of the specific heat and the thermal expansion close to the melting point in ammonia solid III,” PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING, pp. 13–18, 2009, Accessed: 00, 2020. [Online]. Available: