21. Spin welding is a particular form of frictional welding. 22. This effect depends on the tangential compliance and frictional effect in the collision. 23. Frictional unemployment coincides with an equal number of vacancies.24. Grease-lubricated bearings have greater frictional characteristics due to their high viscosity. 25. Earthquakes only exist because there is a very large loss in frictional strength. 26. The relationship between frictional interactions and asperity geometry is complex and poorly understood. 27. The differential diagnosis includes intertrigo, candidiasis, and frictional or contact dermatitis. 28. For more information on frictional forces, see friction. 29. These machines exploit the increased frictional forces found at the micro or nanoscale. 30. Where f _ r is the frictional drag coefficient.
