Peacefully on May 1, 2020. Son of Ans and Frits Landheer. Much loved and will be forever missed by his wife Carolyn Clarke, sons Alex and Karl Landheer, and brother Bram Landheer (Nadrine). Dolf obtained a PHD in physics from the University of Toronto and was a post-doctoral fellow at the University of London, UK. He worked as a Principal Research Scientist at the National Research Council and was a member of the Electro Chemical Society. He enjoyed cycling and travel. We wish to thank the nurses at the Civic hospital for their loving care and compassion. As an expression of sympathy contributions to the Ottawa Hospital Foundation would be appreciated. A memorial will be held at a later date.