John Greenhalgh Parker

Research Physicist

John Greenhalgh Parker, 78, a physicist whose research has led to improvements in gas lines and cancer investigation, died of leukemia Oct. 9 at Shady Grove Adventist Hospital. He lived in Olney.

Dr. Parker, who worked for 38 years at Johns Hopkins University's Applied Physics Laboratory, did fundamental research in molecular physics, acoustics, photoacoustics, laser applications, infrared detection and cancer phototherapy.

His acoustics work led to applications for detecting leaks and corrosion in underground natural gas distribution lines. He developed an infrared detection system that is used in photodynamic cancer treatment, working with the Roswell Park Cancer Institute in Buffalo.

Dr. Parker held four patents and published more than 40 scientific articles in his fields of interest.

He was born in Providence, R.I., and served in the Naval Reserve during World War II. He received three degrees from Brown University in Providence: a bachelor's in electrical engineering in 1947, a master's in physics in 1950 and a doctorate in physics in 1952.

He worked for the Institute for Cooperative Research at Johns Hopkins for a year while working toward his doctorate, then moved to the U.S. Naval Research Laboratory's sound division, where he did theoretical studies of underwater sound propagation. He began working in the Applied Physical Lab's research center in 1956 and stayed there until he retired in 1994.

He coached youth football and baseball and enjoyed long hikes with his dogs through the fields of Olney and in the mountains of Virginia. He especially enjoyed the Rhode Island shore.

His son Andrew Parker died in 2002.

Survivors include his wife, Patricia Webb Parker of Olney; three children, Bruce Parker of Wolftown, Va., Pamela Parker of Olney and Rebecca Shuey of Frederick; a sister; and seven grandchildren.

Joseph D. O'Connell Sr.


Joseph Daniel O'Connell Sr., 91, a native Washingtonian and certified public accountant, died of respiratory arrest Oct. 12 at Holy Cross Hospital in Silver Spring.

Mr. O'Connell was born at his family's home in Southwest Washington and grew up in Northeast Washington. He was a 1932 graduate of Gonzaga College High School.

As a young man, he raised homing pigeons and delivered newspapers. After high school, he worked at the central post office while studying for his accounting degree at night at the old Columbus University School of Accounting. During World War II, he worked as an accountant at Stone Straw Co., whose Washington factory had been converted to manufacture bomb casings.

About 1945, Mr. O'Connell moved to Silver Spring, where he started an accounting firm, working with several partners over the years. He became a certified public accountant in 1949.

He was a member of both the American Institute of Certified Public Accountants and the Maryland Association of Certified Public Accountants; the old Silver Spring Board of Trade; and St. Michael the Archangel and St. Andrew the Apostle Catholic churches in Silver Spring.

For the past 35 years, Mr. O'Connell owned a farm in Thurmont, Md. He was a longtime fisherman of the Chesapeake Bay and Atlantic Ocean.

His wife of 66 years, Irene R. O'Connell, died in 2004.

Survivors include five children, Jean Marie Calder and Elizabeth H. Wassner, both of Silver Spring, Joseph D. O'Connell, Jr. of Gaithersburg, Michael P. O'Connell of Charleston, S.C., and Mary Louise O'Connell of Ridgefield, Conn.; 13 grandchildren; and a great-granddaughter.