Undulatory motion is common to many creatures across many scales, from sperm to snakes. These organisms must push off against their external environment, such as a viscous medium, grains of sand, or a high-friction surface; additionally they must work to bend their own body. A full understanding of undulatory motion, and locomotion in general, requires the characterization of the material prope...

abstract statement of problem: the viscosity of orthodontics adhesive primers is crucial for stability and correct brackets ‘position during bond up. an excessive adhesive flow during brackets seating could change the brackets’ position. objectives: the main purpose of this study was to investigate the viscosity of four orthodontic adhesive primers in two different temperatures. materials and m...

Mechanical energydissipation is important forvibrationdampingandsoundabsorption. Thispaperprovides an analytical model for the interfacial-friction-based viscous behavior of exfoliated graphite, thereby establishing a methodology that may be applied to such behavior of materials in general. This model is in contrast to the conventional bulk viscous deformation model. It can be used to predict t...

The rolling motion of a rigid cylinder on an inclined flat viscous surface is investigated and the nonlinear resistance force against rolling, FR(v), is derived. For small velocities FR(v) increases with velocity due to increasing deformation rate of the surface material. For larger velocity it decreases with velocity due to decreasing contact area between the rolling cylinder and the deformed ...

According to the Saffman–Taylor criterion there is no instability when a more viscous fluid is displacing a less viscous one in a Hele-Shaw cell. Yet an instability was observed experimentally (Chan et al. 1997) in the same classical set-up but with the inner walls of the cell coated with surfactant solution. Linear stability analysis is applied to reveal the basic mechanism of this new instabi...