* Louis H. Hempelmann, 79, an authority on radiation biology who worked on the first atomic bomb, died Wednesday of complications from a stroke in Rochester, N.Y. He was teaching radiology in St. Louis when he joined the Manhattan Project at Los Alamos, N.M., during World War II to help develop the world's first atomic weapon. After he left the government in 1948, He continued to work at Los Alamos on a contract basis.
* Sophia Yarnall Jacobs, 91, author and lifelong advocate of civil and human rights, died of congestive heart failure Wednesday at her home on Mount Desert Island in Northeast Harbor, Maine. In 1959, Mrs. Jacobs took part in the first "woman-to-woman" exchange between the United States and the Soviet Union. Mrs. Jacobs became president of the National Council of Women in 1960 and was chairwoman of the 75th anniversary of the International Council of Women and the group's national affiliate, in Washington, D.C., in 1963.
* Madeleine Marshall Simon, 93, a singing coach and concert pianist who taught English diction at the Juilliard School of Music for more than 50 years, died June 27 of complications from a heart attack at St. Lukes-Roosevelt Hospital Center in New York. Known professionally as Madeleine Marshall, she wrote "The Singer's Manual of English Diction," which has been a standard guide on the subject since 1953.