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
Nambu Type 90 than the Imperial Army's Type 10 for a few good reasons. First, they were made in lower numbers than the Army type. Second, they were usually issued to ships and Naval aircraft and were lost when they were destroyed or sank. Third, Soldiers and Marines who found flare guns on the battlefield often threw them away, as they were not seen as collectable as pistols, rifles, or knives. In Hollywood movies (like "Demolition Man (1993)" and "Waterworld (1995)"), the Type 90 is used erroneously as a stand-in for a futuristic shotgun pistol. Nambu Type 90 The Nambu Type 90 was