The paper presents a comprehensive study of the surfaces of plastic samples (90% polysulfone (PSU) + 10% polycarbonate (PC)) modified with the help of an ultrasonic resonator to reduce friction in contact between the material of aluminum skins and a covering puncheon. Comparative characteristics of surfaces have been obtained. such as: microhardness. coefficient of friction and wear r... https://www.ealisboa.com/mega-sale-Sol-Sunguard-Altitude-Sunscreen-1-5oz-big-savings/