The critical temperature Tc of recent oxide superconductors in Ba-Y-Cu-O systems is considered from the complete electron-phonon interactions in two-dimensional [CuO2]-layers. It is concluded that the value of Tc does not exceed 110 K, so long as the phonon-mechanism is assumed.

Assuming a perfect circulary polarized radar system, the cancellation ratio limitations were evaluated using the Sekine-Lind rain-drop distribution. Numerical methods were used and the cancellation limitation was plotted against rainfall rate for various wind velocities.