Dr. W. (Bill) Wei (1955) is a retired senior conservation scientist in the Research Department of the Cultural Heritage Agency of the Netherlands (RCE - Rijksdienst voor het Cultureel Erfgoed). He has a B.S.E. in mechanical engineering from Princeton University (1977) and a Ph.D. in materials science from the University of Illinois at Urbana-Champaign (1983). Before working in the cultural heritage field, he spent almost twenty years in industrial research and development in the areas of advanced materials, mechanical properties, fracture mechanics and fatigue, and corrosion. He has been conducting research into and consulting on the effects of vibrations and mechanical stresses on the condition of fragile works of art and cultural heritage for more than twenty years. He has recently retired from the RCE and is now an independent consultant.