The fourth seminar, held on May 30, 2006 at Northwestern
University, included lectures by Dr. Laure Dussubieux, a scientist in
the Laboratories for Archaeogeochemistry of the Field Museum of Natural
History; Richard Brow, Curators’ Professor of Materials Science
and Engineering at University of Missouri, Rolla; David Seidman, Walter
P. Murphy Professor of Materials Science and Engineering at Northwestern
University; and Pamela Vandiver, Professor of Materials Science and of
Anthropology at the University of Arizona. The seminar focused largely
on analytical techniques used to study the chemical composition and structure
of ceramics and glasses, as well as the corrosion of these materials.
Laure Dussubieux demonstrated the use of laser ablation/ inductively coupled
- mass spectrometry (LA-ICP-MS) to group various artifacts made of ancient
glass into specific regions of South and Southeast Asia, based on specific
impurity contents. Professor Richard Brow provided a comprehensive overview
of spectroscopic tools that can be used to study the composition and structure
of amorphous materials. These included Raman spectroscopy, nuclear magnetic
resonance spectroscopy, and X-ray absorption fine structure spectroscopy
to probe the atomic arrangements that affect the macroscopic properties.
Surface-sensitive techniques, including X-ray photoelectron spectroscopy
and secondary ion mass spectrometry, provide details about the composition
and structure of glass surfaces and how they change with time and exposure
to ambient conditions. Professor David Seidman described a local-electrode
atom-probe (LEAP) tomograph for studying the chemistry and structure of
materials with sub-nanoscale resolution in three-dimensions. The LEAP tomograph
can analyze, atom-by-atom, a volume of material from a region of a specimen
that has a cross-sectional area of 100x100 nm2 and a depth of many micrometers.
Seidman presented examples of precipitation studies in metallic alloys
and demonstrated how the technique can be modified for ceramic specimens.
Finally, Professor Pamela Vandiver’s keynote presentation focused
on the preservation of objects of cultural heritage by working with art,
artifacts, and sites. She described case studies of Chinese ceramic technology
and glazes produced along the Uzbek Silk Route, detailing her visits to
these sites and work with local craftsman. Vandiver explained how
these studies play a role in the University of Arizona’s program
in Heritage Conservation Science.
The program drew approximately 40 attendants from the Field Museum, the
Oriental Institute, Argonne National Laboratory, the Chicago History Museum,
Indiana Historical Society, Litarini Restoration Studios, McCrone Associates,
and the Milwaukee Art Museum, in addition to faculty and staff from Northwestern
University and the Art Institute of Chicago. Pamela Vandiver’s lecture
was part of the Material Science and Engineering Colloquium Series and
attracted more than 100 people.
The fourth seminar
will be held at Northwestern University in Evanston on May 30, 2006.
Agenda
of the day
Abstracts and Bios |
The Fifth Seminar was held on September 12th, 2006, at the Art Institute
of Chicago. The seminar focused on research and innovations in 3D and
X-ray imaging, with discussions of theory, instrumentation and applications
of X-ray CT-scanning, 3D laser reconstructions and multiple-angle raking
light imaging.
 Lec Maj, Computer Research Assistant in the Division of Humanities at
the
University of Chicago, presented a lecture entitled, "The Xiangtangshan
Cave Project: 3D Digital Reconstruction and Re-contextualization." These
6th- century Buddhist cave shrines in the Fengfeng Mining District, Hebei
province, in China have been looted and sculptures removed or destroyed
at the beginning of the 20th century. The project is
engaged in digital preservation and reconstruction of the caves. Using
a 3D laser surface scanner, Maj led a team that traveled to China and
several museums in Europe and the United States to image fragmentary
sculptural groups. Maj also discussed opportunities of creating a direct
reproduction from the 3D model and the challenges in making this research
accessible via the Web.
 Jack Tumblin (Assistant Professor in the Electrical Engineering and Computer
Science Department of Northwestern University’s McCormick School
of Engineering and Applied Science) delivered a short talk entitled, “Discovering Pentimenti in
Paintings from 4D Reflectance and Merged Visualizations,” an overview
of the development of a prototype of a raking light camera apparatus
for thorough documentation of large paintings illuminated from several
angles
.
 Professor David Channin (Associate Professor, Head of Imaging Informatics
and Medical Director PACS, Northwestern University Medical School, Department
of Radiology) provided a comprehensive overview of the evolution of X-ray
Computer Assisted Tomography (CAT) in his lecture, "Digital Medical
Imaging: A State of the Art." Discussing both theory and instrumentation,
Channin highlighted the comparison of the issues at play in medical versus
artifact radiology, as well as a discussion of the advantages of digital
versus film radiography.
 Moving from the theory to practice of CT-scanning technology for museum
objects, JP Brown, Associate Conservator, and William Pestle, Collections
Manager, both of the Department of Anthropology at the Field Museum of
Natural History, presented their talk humorously entitled, “I
Can See Through Your Skirt, I've Got X-ray Specs: Opportunities and Limitations
of Three-Dimensional Imaging Using Medical Computed Tomography, Examples
from the Field Museum.” Brown and Pestle presented compelling images
of three-dimensional volume renderings of CT-scan generated slice data
for museum purposes. Examples included: detecting organic remains in
archaeological pottery; elucidating modern and historic repairs to polychrome
wood statuary; the engineering of the aesthetic of “proper posture” in
the production of mummified animals in classical Egypt; and using medical
CT to penetrate rock matrix to show fossils inside.
 Finally, the keynote lecture entitled, “Reflectance Imaging: A
Simple Approach to Capturing Surface Detail,” was delivered by
Tom Malzbender, Senior Research Scientist in the Mobile and Media Systems
Lab of Hewlett-Packard Laboratories. Malzbender is an innovator in technology,
who most notably collaborated with the National Gallery in London to
develop hardware and software for a technique called Polynomial Texture
Mapping. The technique has allowed the Gallery to image a number of small
paintings and then simulate raking light illumination at any angle of
incidence, thus allowing enhancement of the visualization of surface
texture effects. Malzbender discussed five years of practical experience
with this innovative method in the areas of paleontology, archeology,
criminal forensics, and artifact and art conservation. Demonstrations
and tools useful for experimentation were described with emphasis on
visualization techniques that may help art professionals and archaeologists
learn more about the objects in their care.
A panel discussion concluded the seminar, aiming at provocatively bringing
the discourse back to what is needed and what is available in the area
of multispectral and multidimensional imaging in museums, after having
presented the most cutting edge advancements in technology .
The panelist were Elizabeth Walmsley, Painting Conservator at the National
Gallery of Art in Washington, DC; Allison Langley, Assistant Painting
Conservator at the Art Institute of Chicago; and Robert Erdmann, Professor
in the Department of Materials Science and Engineering and the Program
in Applied Mathematics at the University of Arizona. Each panelist introduced
the discussion with a short five-minute presentation. Walmsley, representing
an authoritative voice from museums, shared thoughts on the limitations
often encountered in reading and interpreting conventional X-rays and
provided some details on what improvements would be welcome in the field.
Langley gave an overview of current practices and described the use of
both digitized and film X-ray for technical research, with specific examples
from recent research on Georges Seurat's painting Sunday on La Grande
Jatte. Of particular interest was her description of the dynamic
process of using Photoshop to create overlays and enhance digitized X-rays,
yet confirming and refining conclusions by referring back to film X-rays.
Finally, Erdmann discussed advantages and limitations of custom built
and commercially available software that can help in the process of mosaicing
multi-tiled images (especially X-rays), in comparison with manual stitching.
He described how customized software can help remove digital artifacts
and improve legibility, and also listed steps that make the software
more user-friendly and capable of managing digital files of large dimensions.
The fall seminar witnessed unprecedented response and the widest participation
to date, a testament to the fact that visualization technologies spanning
the range from infrared to visible to X-ray digital and digitized images
are very important, highly debated topics in the field at this time.
Over 60 people attended the lectures, including AIC conservators and
curators, faculty and students from the University, and colleagues from
near and far, including: the Field Museum, the Oriental Institute, Argonne
National Laboratory, the Chicago History Museum, the Illinois Institute
of Technology, the University of Chicago, the McCrone Associates, the
Milwaukee Art Museum, the National Gallery (Washington, DC), the Worcester
Art Museum, the Freer and Sackler Galleries, and the Museum Conservation
Institute (Washington, DC) and the Saint Louis Art Museum.
Agenda
of the day
Abstracts and Bios |
