Yuri B. Melnichenko of Oak Ridge National Laboratory’s Biology and Soft Matter Division passed away on March 18, 2016, in Knoxville, Tenn.

Melnichenko studied physics at Kiev State University in the Ukraine, receiving his master’s degree in 1976 and Ph.D. in 1985. He went on to receive a Doctor of Science, Physics, and Mathematics from the Ukrainian Academy of Sciences’ Institute for Macromolecular Chemistry (IMC) in 1992.

By the end of 1980s, Melnichenko started his first small-angle neutron scattering (SANS) experiments with M. Agamalian at the St. Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia. Successful collaboration between PNPI and IMS resulted with his first publication related to the SANS study of critical phenomena in polymer solutions (Yu. Melnichenko et al., Europhysics Letters, 1992, 19, 355).  

He came to ORNL in 1995 to work with G.D. Wignall, D. Selby and their team who designed and built two user-dedicated state-of-the-art SANS instruments at the ORNL High Flux Isotope Reactor (HFIR).

Melnichenko was an established expert in the application of SANS as a vital research tool for structural characterization of various materials. His work focused on a relatively new area of research for SANS: the structure and dynamics of confined fluids, and was the author or coauthor of more than 160 peer-reviewed scientific articles.  

In 2005, he was elected a fellow of the American Physical Society for “Significant contributions to the fundamental science underlying universal aspects of macromolecules in polymer solutions, supercritical mixtures and polymer blends.”

He served as an instrument scientist for the GP-SANS instrument at HFIR since its commissioning in 2007, serving as a local contact for numerous graduate and Ph.D. students as well as visiting scientists in a wide variety of different investigations. 

In 2013, he became the recipient of the Society of Organic Petrology award for the best refereed paper for coal and hydrocarbon source rock geochemistry (the Dal Swaine Award). The results of his research were summarized in his book published in 2015, “Small-angle Scattering from Confined and Interfacial Fluids: Applications to Energy Storage and Environmental Science.”

His most recent interests were in the area of high-pressure absorption and dynamics of fluids contained in pores of engineered and natural porous materials.   

In his free time, Yuri enjoyed art, music, hiking, reading, playing volleyball, and spending time with his family and friends. He is survived by his wife, father, two children, and two grandchildren.