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    Abstract:
    The heat capacities of V3P and V3Si were measured in the temperature range from 150–350 K. At 298.15 K, we find Cp(V3P)=22.3±.2 J/g atom K and Cp(V3Si)=22.6±0.2 J/g atom K. At 150 K the heat capacity of V3P is 6% smaller than that of V3Si. Our data provide support for a value of 25.6 J/g atom for the standard entropy of V3Si at 298.15 K, and result in an estimated value of 23.5 J/g atom for the standard entropy of V3P at 298.15 K.
    Keywords:
    Standard molar entropy
    Abstract The heat capacity at constant pressure of LiGaO 2 is measured in the temperature range from 180 to 700 K. An analysis of the experimental data shows that the anharmonic contribution to the heat capacity can be described by a polynomial of fourth order in the temperature. The standard enthalpies and entropies relative to 298.15 K are calculated from the measured heat capacity. Estimates of the standard enthalpy and entropy at 298.15 K are given.
    Heat capacity ratio
    Atmospheric temperature range
    Specific heat
    Sigma heat
    Citations (5)
    The specific heat capacity of NTO was determined with continuous Cp mode of microcalorimeter(Micro-DSCⅢ).In the determining temperature range from 283K to 353K,the special heat capacity of NTO presents good linear relation with temperature,the relationship between the specific heat capacity of NTO and the thermodynamic temperature was Cp=0.2806+2.7103×10-3T,the standard mole specific heat capacity of NTO was 141.53J/mol/K in 298.15K.Using the determined relationship of Cp with temperature T,thermodynamic functions(enthalpy,entropy and Gibbs free energy) of NTO between 283K and 353K,relative to the standard temperature 298.15K,were derived through thermodynamic relationship.Using the relationship between Cp and T and the thermal decomposition parameters,the time of the thermal decomposition from initialization to thermal explosion(adiabatic time-to-explosion) was obtained,which is between 1.95s and 1.99s.
    Atmospheric temperature range
    Heat capacity ratio
    Calorimeter (particle physics)
    Citations (9)
    Heat capacity is the most important characteristic of substances, and from its change with temperature one can determine the type of phase transformation, Debye temperature, energy of vacancy formation, coefficient of electronic heat capacity and other properties. In this work, the heat capacity of the АЖ5К10 aluminum alloy was determined in the "cooling" mode, according to the known heat capacity of a reference sample made of M00 copper. To do that, the equations describing their cooling rates were obtained by processing the cooling curves of the samples from the alloys of the АЖ5К10-Ga system and the standard. Further, according to the experimentally found values of the cooling rates of the samples from the alloys and the standard, knowing their masses, the polynomials of the temperature dependence of the heat capacity of the alloys were established, which are described by a four-term equation. Using integrals of specific heat capacity, the temperature dependence of changes in enthalpy, entropy and Gibbs energy was calculated. The obtained dependences show that with an increase in temperature, the heat capacity, heat transfer coefficient, enthalpy and entropy of alloys increase, while the values of the Gibbs energy decrease. In that case, the addition of gallium reduces the heat capacity, enthalpy, and entropy of the АЖ5К10 alloy, while the value of the Gibbs energy increases
    Sigma heat
    Volumetric heat capacity
    Debye model
    The thermodynamic properties of hexagonal TiB2 at high temperature and pressure are calculated by using first principles combined with quasi-harmonic Debye model,including the temperature dependence of the lattice parameter,the bulk modulus B0,the heat capacity Cp and the entropy S under ambient pressure.Meanwhile,the relationship of the temperature with the heat capacity Cp,the entropy S,the coefficient of volume expansion α,the Debye temperature Θ and the heat capacity CV expansion coefficient under different pressures is successfully obtained.The results show the calculated heat capacity Cp and entropy S under ambient pressure are in good agreement with experimental measurements.
    Debye model
    Debye function
    Specific heat
    Ambient pressure
    Citations (1)
    Constant (computer programming)
    Heat capacity ratio
    Calorimeter (particle physics)
    Ideal gas
    Volumetric heat capacity
    Real gas