coefficient of roughness
41Aluminium — Infobox aluminiumAluminium (Audio IPA|En uk aluminium1.ogg|ˌæljʊˈmɪniəm, IPA|/ˌæljəˈmɪniəm/) or aluminum (Audio IPA|En uk aluminum.ogg|/əˈluːmɪnəm/, see spelling below) is a silvery white and ductile member of the boron group of chemical elements …
42Tire — This article is about tires used on road vehicles, including pneumatic tires and solid tires. For railroad tires, see railway tires. For other uses, see tire (disambiguation) or tyre.Tires, or tyres (in American and British English, respectively) …
43Gravity wave — In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media (e.g. the atmosphere or ocean) which has the restoring force of gravity or buoyancy.When a fluid parcel is displaced on an interface or… …
44Polystyrene — For other uses, see Polystyrene (disambiguation). Expanded polystyrene packaging …
45Ball bearing — For individual balls that are sometimes called ball bearings , see Ball (bearing). Working principle for a ball bearing …
46Odor — Aroma redirects here. For other uses, see Aroma (disambiguation). Allegory of the senses by Jan Brueghel the Elder, Museo del Prado An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration,… …
47Fatigue (material) — Metal fatigue redirects here. For the video game, see Metal Fatigue (disambiguation). v · d · e Materials failure modes …
48Wear — For other uses, see Wear (disambiguation). v · d · e Materials failure modes …
49Hydrodynamic lubrication — Hydrodynamic (HD) lubrication (or fluid film lubrication) has essential elements:#A lubricant, which must be a viscous fluid. #Hydrodynamic flow behavior of fluid between bearing and journal. #The surfaces between which the fluid films move must… …
50Superlens — A superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses.[1] In 2000, a type of lens was proposed,… …
