17 April 2010

Thesis: Oddy Test Using Silver Nanoparticle Sensor (2007)

Title: Nanoscience and Nanotechnology Applied to Art Conservation: Improved Oddy Test Using Silver Nanoparticle Sensor
Author: Laura Moussa
University: Carnegie Mellon University
Pages: 63
Year: 2007
Type of document: thesis
Link: http://www.cmu.edu/... (pdf, 4.3 Mb)

Damage to metal artifacts from the materials used for display and storage cases is of great concern to art museums. The current technology used, the “three in one” Oddy Test, tests for the suitability of these construction materials by placing silver, copper, and lead metal coupons in one container along with the material at 60°C and 100% relative humidity. After a 28-day period the metal coupons are assessed for any visual changes. There are many shortcomings to this simple test. It is time consuming, irreproducible, slow, hard to evaluate and most importantly gives no quantitation. A new way to test for the suitability of these materials using a silver nanoparticle sensor is described here. Two types of silver nanoparticle shapes, spherical and triangular, were self-assembled using polyethylenimine (PEI) onto a glass coverslip to produce two different sensors. The spherical nanoparticle sensor gave a yellow color and when evaluated for its sensitivity to hydrogen sulfide gas changed colors from yellow to colorless. The triangular nanoparticle sensor gave a blue color and when evaluated for its sensitivity to hydrogen sulfide gas changed colors from blue to colorless. Color changes were followed through UV-Vis spectrophotometry, which showed a decrease in absorption of the initial characteristic peak after exposure to hydrogen sulfide. Kinetic studies were performed on the spherical and triangular nanoparticles, and the reaction rates were determined to be first-order with k = 0.0002 for the triangular nanoparticles and k = 0.0001 for the spherical nanoparticles. When compared to the Oddy Test, both the spherical and triangular silver nanoparticle sensors reacted fully by showing the characteristic color change before the 28-day period of the test. The nanoparticle sensor will allow for high sensitivity, easy evaluation, and quantitative analysis for corrosive gases that would react with silver.

Table of contents (short version):
Chapter 1-Introduction
Chapter 2- Sensor Fabrication
Chapter 3-Sensitivity of Nanoparticles to Hydrogen Sulfide
Chapter 4-Performance evaluation of Ag nanoparticle sensors
Chapter 5- Conclusion and future work

Article: Composition and condition of naturally aged papers (2008)

Title: Composition and condition of naturally aged papers
Authors: Catherine H. Stephens, Timothy Barrett, Paul M. Whitmore, Jennifer A. Wade, Joy Mazurek, and Michael Schilling
Reference: Journal of the American Institute for Conservation 47, 2008, 201-215
Download: http://www.cmu.edu/... (pdf, 550 Kb)

The properties of forty naturally aged papers taken from books dating from 1477 to 1793 were assessed using two indicators of paper condition: degree of polymerization and yellowness index. These data were interrelated with three variables that may impact long-term paper stability: pH, gelatin content, and residual metals content. More stable specimens (high degree of polymerization and low yellowness index values) were strongly associated with high pH. High pH specimens were found to contain lower amounts of aluminum, potassium, and sulfur, as well as higher amounts of calcium and magnesium. Papers with more than 5.5% w/w gelatin content exhibited high pH, while those containing less than 5.5% w/w gelatin content showed both a range in pH and a broad range of aluminum, potassium, and sulfur content. Consequently, high gelatin content specimens were in good condition while low gelatin content specimens ranged in condition from poor to good. Results suggest that pH is the controlling factor in long-term stability and that gelatin needs to be present above some content level to provide long-term stability. The origin of high pH may lie in the alkaline calcium and magnesium residues.

16 April 2010

Report: Treatment Practices in Photograph Conservation (2009)

Title: Current Status of Treatment Practices in Photograph Conservation
Author: Elia Alejandra Mendoza Olmos
Pages: 62
Year: 2009
Type of document: Report
Link: http://photograph-conservation.blogspot.com/...
Download: http://docs.google.com/... (pdf, 2.8 Mb)

This research is an analysis of the current status of treatment practices in photograph conservation, based on fifteen video taped interviews with senior photograph conservators, conducted from January to May 2009. Te interview questions were designed to define and describe current conservation treatment practices and discuss their transformation over time. Training and future challenges of treatment are discussed briefly. The interviews and the documentation of the research process are available in http://photograph-conservation.blogspot.com.

Table of Contents (short version):
The interviews
Documentation of the Project
Analysis of Results

Article: Authentication (1998)

Title: Authentication: Science & art at odds?
Authors: Duane R. Chartier and Fred G. Notehelfer
Reference: Scientific Detection of Fakery in Art. Proceedings of SPIE (SPIE - The International Society for Optical Engineering). 29-30 January 1998, San Jose, California. Volume P 3315, 74-86, 1998
Link: http://www.conservartassoc.com/spie.html (html)

Contrary to popular belief, there is a very great difference between the detection of forgery versus the authentication of works of art. Science is generally very good at producing evidence of falsification but often is equally poor at proving authenticity. The primary reason for these gross differences is that connoisseurship and art history are more strongly involved in the process of authentication than are scientific testing and analysis. There is also a pronounced lack of substantive interaction between art conservation professionals, scientists and art historians.
The case of a recently discovered painting by John Constable will be used to illustrate the difficulties and opportunities of a balanced and systematic approach to the process of authentication. There is much more than science involved in such endeavors and this would not surprise anyone who has attempted to introduce works of art through non-traditional channels.
Great problems arise when the curatorial community is asked to consider works that do not so easily "fit" into a neat art historical period or stylistic pigeonhole. Connoisseurs often will only accept the best works of an artist and discount the inevitable products of the artist's evolution -- less accomplished works. Scientific principles and technical evidence can and must be used in order to elevate the practice of authentication.

15 April 2010

Article: blue pigments in Portuguese 19th century technical literature (2009)

Title: Traditional and modern blue pigments in Portuguese 19th century technical literature
Author: Sónia Barros dos Santosa, António João Cruz
Reference: Andrea Macchia, Ernesto Borrelli, Luigi Campanella (org.), YOCOCU 2008. Youth in Conservation of Cultural Heritage. Proceedings, Rome, Italian Association of Conservation Scientists - Italian Society of Chemistry, 2009, pp. 44-50
Link: html, pdf (2.6 Mb)

19th century was a period of major chemical discoveries and industrial development that led to the emergence of new pigments. The technical literature of this century suggests that in Portugal traditional blue pigments, which had already been abandoned in other places, continued to be used, with some significance, at the end of the century. On the other hand, it shows that new pigments only began to appear, on average, about 50 or 40 years after their discovery or beginning of commercialization, respectively. However, in the end of the century, international trade marks such as Lefranc were already at painters' disposal.

Article: Direct Digital Image Capture (2005)

Title: Direct Digital Image Capture: Current Practices and Problems
Author: Charles Rhyne
Reference: Visual Resources: An International Journal of Documentation, Vol. XXI (June 2005), pp. 214-219
Link: http://academic.reed.edu/... (html)

To document current practices, a survey was conducted of digital imaging procedures currently used at American Museums, Libraries, Archives, and other cultural institutions. Over forty institutions submitted answers to the questionnaire. Because no comparable survey has been conducted, the results should be of considerable interest to cultural institutions, indeed to anyone interested in high quality digital photography.

200 posts!

Believe it or not... this is already my 200th post!

Article: Do standard temperatures need to be constant? (2009)

Title: Do standard temperatures need to be constant?
Authors: Morten Ryhl-Svendsen, Lars Aasbjerg Jensen, Poul Klenz Larsen and Tim Padfield
Reference: Going Green: towards sustainability in conservation, 24 April 2009
Link: html, pdf (1.7 Mb)

Three methods of controlling relative humidity (RH) in museum stores are compared for energy use, based on data from three buildings. Full air conditioning is by far the most expensive. Next is conservation heating. Dehumidification without temperature control is by far the cheapest solution. Thermal and humidity buffers allow both conservation heating and dehumidification to operate within a safe annual temperature cycle: 15°C - 25°C for conservation heating, 10°C - 15°C for dehumidification. The saving in energy by using dehumidification rather than air conditioning is so large that the requirement for constant temperature expressed in many museum standards should be abandoned in favour of a permitted annual cycle within the range 10°C to 25°C. This will also give better chemical durability to organic materials than standards based on conditions for human comfort.

Article: restoration of historic buildings between 1835 and 1929 (2005)

Title: The restoration of historic buildings between 1835 and 1929: the portuguese taste
Authors: Lúcia Rosas
Reference: e-journal of Portuguese History, Vol. 3, number 1, Summer 2005
Download: http://hdl.handle.net/... (pdf, 295 Kb)

The glorification of the historical monument - a European phenomenon that emerged during the first quarter of the 19th Century - occupied a place of great theoretical and iconographic importance in the Portuguese press. Through engravings, its image attained a power of synthesis, both in the creation of symbols and in the understanding of stylistic categories, becoming a major driving force behind the greater value that was given to the medieval architectural heritage and its consequent restoration. Despite being given a relatively ineffective and somewhat belated administrative and legal framework, the prestige and popularity of medieval monuments were sufficient to ensure a significant number of restoration works after 1840. Literature on art, the press and manuscript sources of the period, sought to identify the principles to underlie the idea of restoration in Portugal between 1839 and 1925, as compared to models adopted throughout Europe. Although Portuguese artistic culture lagged far behind other European nations, the restoration of medieval religious architecture was common practice in Portugal at that time, both due to the idea that unity had always been one of the fundamental principles of architecture and because the cult of monuments stemmed from a mythical and symbolic production of national identity.

13 April 2010

Thesis: Organic residues preserved in ancient vessels (2006)

Title: Molecular studies of organic residues preserved in ancient vessels
Author: Tatiana Frederica Margreta Oudemans
University: University of Amsterdam
Year: 2006
ISBN-13: 978-90-77209-12-7
Type of document: PhD thesis
Download: http://www-old.amolf.nl/... (pdf, some chapters available)

From the Introduction:
This study is aimed at the molecular characterisation oft he organic residues preserved in an assemblage of ceramic vessels originating from an indigenous settlement dating from the Iron Age and Roman period at Uitgeest – Groot Dorregeest in the Netherlands in order to better infer the way the vessels were originally used.

Table of Contents (short version):

1. General Introduction
2. Studying Vessel-Use using Curie-Point Pyrolysis Mass Spectrometry and Multivariate Analysis
3. Molecular Characterisation of Solid Organic Residues by Curie-Point Pyrolysis Gas Chromatography/Mass Spectrometry
4. Identifying Biomolecular Origins of Solid Organic Residues using Direct Temperature - resolved Mass Spectrometry and Multivariate Analysis
5. (under embargo)
6. (under embargo)
7. General Discussion
Appendix 1: Materials
Appendix 2: DTMS and DTMS/MS Study of Solid Organic Residues
Appendix 3: Organic Residue Analysis in Ceramic Studies - Implications for Conservation Treatment and Collections Management

Archaeometry of Pre-Columbian Sites and Artifacts (1994)

Title: Archaeometry of Pre-Columbian Sites and Artifacts: proceedings of a symposium organized by the UCLA Institute of Archaeology and the Getty Conservation Institute, Los Angeles, California, March 23-27, 1992
Editors: David A. Scott, Peter Meyers
Publisher: The Getty Conservation Institute
Pages: 437
Year: 1994
ISBN: 0-89236-249-9
Download: http://www.getty.edu/... (pdf, 10.3 Mb)

Table of Contents:

The Materials Science of Material Culture: Examples from the Andean Past, Heather Lechtman

Pre-Columbian Pottery: Research in the Maya Region, Ronald L. Bishop

Kiln Firing at Batan Grande: Today and in Formative Times, Ursel Wagner, et. al.

Ceramics Among the Hohokam: Modeling Social Organization and Exchange, David R. Abbot and David M. Schaller

New World Obsidian: Recent Investigations, Michael D. Glascock

Obsidian Artifacts from Oaxaca, Mexico: Source Identification and Hydration Dating, J. Michael Elam, Michael D. Glascock, and Hector Neff

Obsidian from Pueblo Grande, Arizona: Modeling Social and Economic Patterns in Lithic Procurement, Jane Peterson, Douglas R. Mitchell, and M. Steven Shackley

Beads from Sipan: A Functional Analysis, Leonard Gorelick and John Gwinnett

Silver and Lead in the Late Prehistory of the Mantaro Valley, Peru 183, Ellen G. Howe and Ulrich Petersen

Pre-Hispanic Copper Alloy Production at Batan Grande, Peru: Interpretation of the Analytical Data for Ore Samples, J. F. Merkel , I. Shimada, C. P. Swann, and R. Doonan

Native Copper Technology and Society in Eastern North America, S. Terry Childs

Chemical Seriation of Northeastern North American, Archaeological Sites Using Copper Artifacts, R. G. V. Hancock, L. A. Pavlish, R. M. Farquhar P. J. Julig, and W. A. Fox

Pre-Columbian Gold Processing at Putushio, South Ecuador: The Archaeometallurgical Evidence, Thilo Rehren and Mathilde Temme

Pre-Hispanic Platinum Alloys: Their Composition and Use in Ecuador and Colombia
David A. Scott and Warwick Bray

Pre-Hispanic Goldwork from the Museo de America, Madrid: A New Set of Analyses, Salvador Rovira

A Methodology for the Study of Buried Archaeological Sites, Luis Barba

Exceptional Molecular Preservation in the Fossil Record: The Archaeological, Conservation, and Scientific Challenge, Noreen Tuross and Marilyn L. Fogel

Stratigraphic Dating and Cultural Sequences of Pre-Hispanic Northern South America, Thomas van der Hammen

Coloration in Etowah Textiles from Burial NQ 57, Lucy R. Sibley and Kathryn A. Jakes

Radiocarbon Dates of Teponaztlis from Mexico, Reiner Protsch von Zieten and Rainer Berger

12 April 2010

Article: Defects and moisture problems in buildings (2006)

: Defects and moisture problems in buildings from historical city centres: a case study in Portugal

Authors: Eduarda Luso, Paulo Lourenço, Manuela Almeida
Type of document: article draft
Journal: Building and Environment 41:2, 2006, p. 223-234
Download: http://hdl.handle.net/... (pdf, 1.4 Mb)

Conservation of ancient buildings is a major issue for modern societies, both from economical and cultural viewpoints. Information about the ancient built heritage is vital to plan adequate remedial measures. Using a historic centre in Portugal as a case study, this paper presents an extensive survey of building typology and materials, damage in the building envelope, indoor survey of damage, and measurements in indoor air temperature and relative humidity. Water-related problems can be confirmed as the single most important defect, which are combined with inadequate sun exposure, ventilation and heating, and excessive moisture indoor production. Extremely low temperatures, high humidity and presence of mould therefore compromise the indoor quality of life of the inhabitants, being urgent repair needed at many levels.

Article: Digital Archaeology (2009)

Title: Digital Archaeology: Recovering Digital Objects from Audio Waveforms
Authors: Mark Guttenbrunner, Mihai Ghete, Annu John, Chrisanth Lederer, Andreas Rauber
Reference: iPres 2009, 5-6 October 2009, in San Francisco, California
Link: Article: http://www.planets-project.eu/... (pdf, 241 Kb)
: http://www.planets-project.eu/... (pdf, 255 Kb)

Specimens of early computer systems stop working every day. It is necessary to prepare ourselves for the upcoming situation of having storage media and no working systems to read data from these carriers. With storage media residing in archives for already obsolete systems it is necessary to extract the data from these media before it can be migrated for long term preservation. One storage medium that was popular for home computers in the 1980s was the audio tape. The first home computer systems allowed the use of standard cassette players to record and replay data. Audio tapes are more durable than old home computers when properly stored. Devices playing this medium (i.e. tape recorders) can be found in working condition or can be repaired as they are made out of standard components. By re-engineering the format of the waveform the data on such media can then be extracted from a digitized audio stream. This work presents a case study of extracting data created on an early home computer system, the Philips G7400. The original data formats were re-engineered and an application was written to support the migration of data stored on tapes without using the original system. This eliminates the necessity of keeping an obsolete system alive for preserving access to data on storage media meant for this system. Two different methods to interpret the data and eliminate possible errors in the tape were implemented and evaluated on original tapes recorded 20 years ago. Results show that with some error correction methods parts of the tapes are still readable, even without the original system. It also becomes clear, that it is easier to build solutions now when the original systems are still available.

11 April 2010

Article: Clean Art? (2006)

Title: Clean Art?
Author: Charles S. Rhyne
Reference: Journal of the American Institute for Conservation Vol. 45, Fall/Winter 2006, pp. 165-170
Download: http://academic.reed.edu/... (html)

Originally presented as the introduction to a session on the cleaning of art at the 2004 annual meeting of the American Institute for Conservation of Historic and Artistic Works, this paper is not limited to one type of art but attempts to consider issues relevant to all forms, materials, uses, and periods, from any region or culture. It encourages what might be called “comparative conservation.” The article focuses on the diverse purposes for which art is cleaned, and attempts to facilitate the ongoing discussion of the values embodied in these choices and the means to achieve them.

Before the Unthinkable... Happens Again (2009)

Title: Before the Unthinkable Happens Again
Meeting: International roundtable discussion, July 22, 2009, Tokyo, Japan
Organisation: International Institute for Conservation
Year: 2009
Type of document: transcription of meeting
Download: http://www.iiconservation.org/... (pdf, 734 Kb)

An international roundtable discussion on the need for seismic mitigation research and applications for cultural heritage.
If statistics are correct, many of the world’s cultural centres will experience major earthquakes in the first few decades of the 21st century. Many have recently suffered the effects of significant seismic events (the Abruzzo earthquake in Italy being only one). Time is therefore not in preservation’s favour and immediate action is paramount. The needs for collaborative efforts in research and implementation, policy development and outreach are clear, and nothing less than the survival of much of the world’s cultural treasures is at stake.
Eight colleagues from five countries that regularly experience significant earthquakes agreed to consider a series of questions and to discuss with each other, and the audience in Tokyo, the way forward in protecting collections from damage due to earthquakes. These panellists have produced some of the best international research in seismology, engineering, education, policy and mitigation implementation to date and they lead the field with their knowledge and commitment.