Contact angle a contact angle of 0°. This is often the case for water on bare metallic or ceramic surfaces, although the presence of an oxide layer or contaminants on the solid surface can significantly increase the contact angle. Generally, if the water contact angle is smaller than 90°, the solid surface is considered hydrophilic and if the water contact angle is larger than 90°, the solid surface is considered hydrophobic. Many polymers exhibit hydrophobic surfaces. Highly hydrophobic surfaces made of low surface energy (e.g. fluorinated) materials may have water contact angles as high as ~120°. Some materials with highly rough surfaces
Type 90 Kyū-maru tank made Type 90 more challenging to operate outside Hokkaido. Some politicians therefore criticized the effectiveness of Type 90 due to difficulty in transportation. In fact, more than 65% of major bridges in Japan were still considered passable for Type 90 while overseas main battle tanks such as Challenger 2 and Leopard 2 could only use 40% of bridges in Japan. Type 90 Kyū-maru The is a main battle tank (MBT) of the Japan Ground Self-Defense Force (JGSDF). It was designed and built by Mitsubishi Heavy Industries as a replacement for all deployed Type 61 and Type 74 tanks, and