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 kW (1,500 horsepower). The hydropneumatic suspension units are mounted on the front and rear pair of road wheels, which can be adjusted on-the-fly to deal with uneven terrain, a requirement on Japan's rough, mountainous terrain. According to the Japanese Ministry of Defense official data report, the acceleration of the type is 0–200 m in 20 seconds. The Type 90 has an approximate unit cost of 790 million Japanese yen or approximately 7.4 million US dollars at 2008 exchange rates. 341 Type 90 tanks were produced between 1990 and 2009 with an average annual production number of 19 vehicles. The original