Usually, this requires cleaning, descaling, roughening, and/or blasting of the faying surfaces. Scanning electron microscopy shows that HS-1 causes roughening and blebbing of bacterial cell surfaces. The cell walls of fungus have a distinct roughening. The drawback of laser roughening is the cost of the equipment and tooling. Symptoms unique to guinea pigs include crouching with half-closed eyes and roughening of the hair. They were probably used as hammerstones or for roughening the surface of a grinding stone. The infection causes a roughening of the inner surface of the eyelids. BL control (roughening) was applied to golf balls in the 19th century. This roughening optimizes ink flow characteristics over the feed surface. In addition, roughening the surface will also increase mechanical interlocking. The plant has smooth bark, dark-greenish when young, but roughening with age. Oftentimes, the laser roughening is done in ambient conditions with or without argon shielding gas. Roughening of the serosal surface of the intestine can occur secondary to peritonitis. If pass through windows are not available then laser roughening is a good option. Special roughening tools called 'rockers' have been in use since at least the eighteenth century.