def Param_m(self, h, Kcopper, Diameter_mm):
    m = np.sqrt((((4 * h) * 0.2) / (Kcopper * (Diameter_mm / 1000))))
    return m
def Param_m(self, h, Kcopper, Diameter_mm):
    m = np.sqrt((((4 * h) * 0.2) / (Kcopper * (Diameter_mm / 1000))))
    return m