Determination of the specific heat capacity of a graphite sample using absolute and differential methods

Abstract

An experimental assembly has been constructed to measure the specific heat capacity of macroscopic graphite samples at room temperature. The same batch of graphite constitutes the core of a graphite calorimeter, which is currently being realized to measure the absorbed dose due to ionizing radiation. Two different experimental procedures have been applied. In the first method the specific heat capacity of graphite was measured directly, where its value is corrected for the influence of impurities. The second method, to our knowledge not previously applied to macroscopic samples, is based on a series of differential measurements where no correction for added impurities is needed. By its nature, the second method reduces systematic effects. The specific heat capacity of a particular graphite sample is determined to be 706.9 J K −1 kg −1 with a combined relative standard uncertainty of 9 parts in 10 4 at 295.15 K. The specific heat capacity of cyanoacrylate has also been determined.

Modeling of Thermal Conductivity of Graphite Nanosheet Composites

“…C p,f (specific heat of graphite) of 0.70 J g À1 K À1 is taken. 11 x is the mass fraction of GNS in the nanocomposite sample. It is presented in Ref.…”

Photoacoustic imaging reveals hidden underdrawings in paintings

“…Since the absorption coefficient μ α of graphite, which is the main absorbing material in the examined paintings for the Nd:YAG line 33 , has a value of 2.4 × 10 5  cm −1 , A e  ≈ 20 J/cm 3 . For typical values of graphite density 34 and specific heat capacity 35 at room temperature ( ρ  = 2.25 g/cm 3 and C V  = 0.7069 JK −1 g −1 respectively), Eq. 1 yields a maximum ( η th  = 1) local temperature rise of ΔΤ ≈ 12.6 Κ per laser pulse incident on the sample.…”

Theoretical study of the porosity effects on the shock response of graphitic materials

“…In particular, a sharp temperature increase is found for low shock intensities (+700 K for the intragranular case, +1200 K for the mosaic case) which may result from the closure of the porosity induced by the shock: similar trends are found starting from graphite or diamond. After this initial heating phase, the shock temperatures increase at distinct, quasi constant rates for graphite and diamond (∼37.4 K/GPa vs. ∼63.3 K/GPa respectively) reflecting the difference in heat capacity between the two bulk solids (0.71 kJ/kg/K [26] vs. 0.52 kJ/kg/K [27] at 300 K). Note that the change in magnitude of the computed slopes agree qualitatively with the ones estimated by the bulk EOS (∼12.7 K/GPa vs.…”