France F.G.,Preservation Research and Testing Division
Materials Research Society Symposium Proceedings | Year: 2011
Developments in non-invasive analytical techniques advance the preservation of cultural heritage materials by identifying and analyzing substrates and media. Spectral imaging systems have been used as a tool for non-invasive characterization of cultural heritage, allowing the collection of chemical identification information about materials without sampling. The Library of Congress has been developing the application of hyperspectral imaging to the preservation and analysis of cultural heritage materials as a powerful, non-contact technique to allow non-invasive characterization of materials, by identifying and characterizing colorants, inks and substrates through their unique spectral response, monitoring deterioration or changes due to exhibit and other environmental conditions, and capturing lost and deteriorated information. The resulting image cube creates a new "digital cultural object" that is related to, but recognized as a distinct entity from the original. The range of data this object contains encourages multidisciplinary collaboration for the integration of preservation, societal and cultural information. © 2011 Materials Research Society.
Marengo E.,University of Piemonte Orientale |
Manfredi M.,University of Piemonte Orientale |
Zerbinati O.,University of Piemonte Orientale |
Robotti E.,University of Piemonte Orientale |
And 5 more authors.
Analytical Chemistry | Year: 2011
The aim of this project is the development of a noninvasive technique based on LED multispectral imaging (MSI) for monitoring the conservation state of the Dead Sea Scrolls (DSS) collection. It is well-known that changes in the parchment reflectance drive the transition of the scrolls from legible to illegible. Capitalizing on this fact, we will use spectral imaging to detect changes in the reflectance before they become visible to the human eye. The technique uses multivariate analysis and statistical process control theory. The present study was carried out on a "sample" parchment of calfskin. The monitoring of the surface of a commercial modern parchment aged consecutively for 2 h and 6 h at 80 °C and 50% relative humidity (ASTM) was performed at the Imaging Lab of the Library of Congress (Washington, DC, U.S.A.). MSI is here carried out in the vis-NIR range limited to 1 μm, with a number of bands of 13 and bandwidths that range from about 10 nm in UV to 40 nm in IR. Results showed that we could detect and locate changing pixels, on the basis of reflectance changes, after only a few "hours" of aging. © 2011 American Chemical Society.
France F.G.,Preservation Research and Testing Division
Applied Spectroscopy | Year: 2011
Hyperspectral imaging was originally developed for remote sensing and astronomical applications, but adaptations of this technology have been of great benefit to the preservation of cultural heritage. Developments in noninvasive analytical techniques have advanced the preservation of cultural heritage materials by enabling the identification and analysis of a range of materials, utilizing their unique spectral response to nondestructively determine chemical composition, and determining states of deterioration and change due to environmental conditions. When used as a tool for noninvasive characterization of cultural heritage, these spectral imaging systems allow the collection of chemical identification information about materials without sampling, which is a critical factor for cultural heritage materials. The United States Library of Congress has been developing the application of hyperspectral imaging to the preservation and analysis of cultural heritage materials as a powerful noncontact technique. It allows noninvasive characterization of materials, by identifying and characterizing colorants, inks, and substrates with narrow-band illumination to protect the object while also monitoring deterioration or changes due to exhibit and other environmental conditions. Contiguous illumination from the ultraviolet, visible, and infrared spectral regions allows the capture of lost, obscured, and deteriorated information. The resulting image cube allows greater capabilities for mapping and coordinating a range of complementary chemical and spectral analyses. The capabilities of this technique are illustrated by a review of results from analysis of the Waldseemüller World Map, the L'Enfant plan for Washington, D.C., and the first draft of the U.S. Declaration of Independence. © 2011 Society for Applied Spectroscopy.
Hobaica S.,Preservation Research and Testing Division
Journal of Applied Polymer Science | Year: 2013
Audio magnetic tapes that are difficult to play may be affected by a form of degradation called "sticky shed syndrome" (SSS). SSS exhibits physical symptoms during playing such as squealing, not packing tightly on the reel and possible tape material loss during playing. This research investigated attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to identify spectroscopic markers for SSS in audio magnetic tapes with poly(ester urethane) (PEU) binder layer. This article presents results for applying this technique to 50 audio magnetic tapes from the Library of Congress (LC) collections. This technique and analysis is intended to be used as a tool in identifying audio magnetic tapes with SSS from the mid 1970s through the 90s for improved preservation and to increase workflow in libraries and archives. This ATR-FTIR technique had a success rate of 71% for identifying SSS tapes and 86% for non-SSS tapes. The research also discusses spectral and chemical changes in the PEU binder layer between SSS tapes, non-SSS, and SSS tapes treated by baking including changes in hydrogen bonding of the carbonyl groups. The results support chemical/physical changes occurring in the soft segment of the PEU binder layer of SSS tapes. The absorption ratio of free to hydrogen bonded carbonyl groups was also correlated with SSS. © 2012 Wiley Periodicals, Inc.
France F.G.,Preservation Research and Testing Division |
Christens-Barry W.,Equipoise Imaging LLC |
Toth M.B.,R. B. Toth Associates |
Boydston K.,MegaVision Inc.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
The Library of Congress' Preservation Research and Testing Division has established an advanced preservation studies scientific program for research and analysis of the diverse range of cultural heritage objects in its collection. Using this system, the Library is currently developing specialized integrated research methodologies for extending preservation analytical capacities through non-destructive hyperspectral imaging of cultural objects. The research program has revealed key information to support preservation specialists, scholars and other institutions. The approach requires close and ongoing collaboration between a range of scientific and cultural heritage personnel - imaging and preservation scientists, art historians, curators, conservators and technology analysts. A research project of the Pierre L'Enfant Plan of Washington DC, 1791 had been undertaken to implement and advance the image analysis capabilities of the imaging system. Innovative imaging options and analysis techniques allow greater processing and analysis capacities to establish the imaging technique as the first initial non-invasive analysis and documentation step in all cultural heritage analyses. Mapping spectral responses, organic and inorganic data, topography semi-microscopic imaging, and creating full spectrum images have greatly extended this capacity from a simple image capture technique. Linking hyperspectral data with other non-destructive analyses has further enhanced the research potential of this image analysis technique. © 2010 Copyright SPIE - The International Society for Optical Engineering.