Johns Hopkins Whiting School of Engineering 1996 Annual Report [text version]

Whiting School of Engineering 1996 Annual Report

Seeking Gold in a Baltimore Landmark
Johns Hopkins left his mark on Baltimore in more ways than one. In the 1840s, the Quaker merchant and philanthropist—who was also an insomniac—decided he needed to escape occasionally from the city’s noise and bustle. He purchased a two-story farmhouse in Clifton Park and transformed it into an Italianate villa, complete with a campanile that featured a view of the Baltimore harbor. Hopkins enhanced his “beloved Clifton” with an artificial lake, islands, foot bridges, a greenhouse for orange trees, and 100 pieces of marble statuary. At the time, Clifton was considered one of the premier estates in the country. After Hopkins died in 1873, the villa and grounds went into decline. Originally, Hopkins had intended Clifton to be the site of his university, but eventually the city purchased the property in 1895. In the decades that followed, the mansion served as a clubhouse for the Clifton Park golf course.

In 1993, Clifton became the home of Civic Works, a non-profit, community-based program dedicated to improving the work, education, and citizenship skills of young people in Baltimore. Civic Works decided to restore Clifton, and the Center for Nondestructive Evaluation (CNDE) is playing an important role.

“After a small electrical fire in 1994, we discovered gold leaf decorations on the transom area above one of the doors,” says Tom Ebel, project manager. After finding more gold leaf on a wall in an adjoining room, Civic Works called on CNDE for assistance. “Before beginning extensive renovations, we need to know where the gold leaf is located so we can preserve it,” comments Matthew Mosca, an expert in historical paint research retained by Civic Works.

“Our approach to identifying the gold leaf is to use a nondestructive method that makes the gold react differently from surrounding materials, such as the plaster and lead carbonate paint,” explains Center Director Robert Green. Green, Associate Research Professor John Winter, and post-doctoral fellow Douglas Oursler first tried thermographic imaging. With heat lamps trained on a precise location, the team looked at the spot with an infrared camera. Set at a wave-length of ten microns, the camera would hopefully pick up any changes in heat occurring inside the wall. The camera is so sensitive that it can easily image a handprint left on paper. When thermography failed to produce results, the team moved to microwaves. “In this technique,” says Winter, “microwaves heat the interior of the wall from the inside out. The gold will stop the microwave energy and convert it to heat, which the camera should image.” While the team is refining this approach, they are also considering other methods.

“We are very excited about the project,” states Green, “particularly since the University that is Johns Hopkins’ legacy is helping to restore his home.”

Established 1984

Phone 410-516-6115

Email cnde@jhuvms.hcf.jhu.edu

Executive Committee
Robert E. Green, Jr., Director
Boro Djordjevic, Associate Director
James H. Anderson, Radiology
Frank G. Arcella, Applied Physics Laboratory
Frederic Davidson, Electrical and Computer Engineering
Nicholas P. Jones, Civil Engineering
John C. Murphy, Applied Physics Laboratory
Theodore O. Poehler, Johns Hopkins University
Kenneth A. Potocki, Applied Physics Laboratory
K.T. Ramesh, Mechanical Engineering
Moshe Rosen, Materials Science and Engineering
Murray B. Sachs, Biomedical Engineering
James W. Wagner, Materials Science and Engineering

Research Areas
Advanced Sensors
Advanced Signal Processing
Artificial Intelligence / Neural Networks
Life Cycle Management / Aging Structures
Microelectronic Properties
Process Control

Center for Nondestructive Evaluation Seeking Gold in a Baltimore Landmark Center Facts

Center for Nondestructive Evaluation
Seeking Gold in a Baltimore Landmark
Center Facts