@inproceedings{oai:jaxa.repo.nii.ac.jp:00038390,
 author = {山本, 哲生 and 城野, 信一 and 万代, 英俊 and Yamamoto, Tetsuo and Shirono, Shinichi and Mandai, Hidetoshi},
 book = {第28回月・惑星シンポジウム, Proceedings of the 28th ISAS Lunar and Planetary Symposium},
 month = {Dec},
 note = {A model for a grain aggregate is proposed, where individual grains are composed of atoms with lattice vibration in the potential Phi and the aggregate is composed of those grains bound by the grain-grain interaction potential Phi(sub g). From statistical mechanical consideration, we have derived expressions of thermodynamical quantities such as the Helmholtz free energy, the internal energy, and the pressure P for the grain aggregate. It is shown that the Equation Of State (EOS) of the model grain aggregate has form similar to the Mie-Grueneisen EOS of a bulk solid. For a grain aggregate of volume V and internal energy U(sub g) composed of N grains with the i-th grain having volume V(sub i) and the lattice vibrational energy U(sub i), the EOS derived is given by P = Sigma (from i = 1 to N) of (-derivative of Phi(V(sub i)))+ gamma x ((U(sub i)/V(sub i))) x (partial derivative of V(sub i) wrt. (with respect to) V)) - (derivative of (average of Phi(sub g)(V)) + Gamma x (U(sub g)/V) + T x (partial derivative of S(sub c) wrt. V at constant T), where gamma is the Grueneisen parameter for individual grains, and Gamma is a generalized Grueneisen parameter defined by Gamma is equal to -(partial derivative of ln(E(sub im)(V)) wrt. V at constant T), with E(sub im) being the energy of the m-th state of the i-th grain's motion in the aggregate. Average of Phi(sub g)(V) in the second term on the RHS (Right-Hand Side) is the grain-grain potential averaged in the sense of the Bragg-Williarms approximation over various configurations of grains in the aggregate, and S(sub c) in the 4th term is the entropy resulting from possible configurations of grains composing the aggregate. Properties of the EOS and comparison with experiments and empirical formulae are under study, and detailed description of the results will be given elsewhere., 資料番号: AA0063352023},
 pages = {89--89},
 publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)},
 title = {Equation of state for a grain aggregate},
 year = {1995}
}