def _set_thermal_expansion(self):
    beta = [0.0]
    for i in range(1, (self._num_elems - 1)):
        dt = (self._temperatures[(i + 1)] - self._temperatures[(i - 1)])
        dv = (self._equiv_volumes[(i + 1)] - self._equiv_volumes[(i - 1)])
        beta.append(((dv / dt) / self._equiv_volumes[i]))
    self._thermal_expansions = beta
def _set_thermal_expansion(self):
    beta = [0.0]
    for i in range(1, (self._num_elems - 1)):
        dt = (self._temperatures[(i + 1)] - self._temperatures[(i - 1)])
        dv = (self._equiv_volumes[(i + 1)] - self._equiv_volumes[(i - 1)])
        beta.append(((dv / dt) / self._equiv_volumes[i]))
    self._thermal_expansions = beta