Research papers
Research papers are assigned in both lab and theory classes at UCLA, allowing students to select topics of interest and delve further. Below, I have included the titles and abstracts of a selection of papers I've written as a UCLA/Getty student. Please click on the title to expand.
Conservation of wall paintings at THE Ajanta CAVES, INDIA
Abstract
A variety of efforts addressing the preservation of wall paintings and cave structures at the Ajanta World Heritage site in Central India have occurred since discovery by the Western world in the late nineteenth century. Original wall painting materials have been characterized by researchers using an assortment of analytical methods in order to better understand ancient Indian painting techniques. Material chemistry is also used to better understand how the paintings are affected by the various agents of deterioration present at the site. Through this paper, findings from material characterization studies will be presented, and a selection of conservation methodologies applied over the years will be summarized.
A variety of efforts addressing the preservation of wall paintings and cave structures at the Ajanta World Heritage site in Central India have occurred since discovery by the Western world in the late nineteenth century. Original wall painting materials have been characterized by researchers using an assortment of analytical methods in order to better understand ancient Indian painting techniques. Material chemistry is also used to better understand how the paintings are affected by the various agents of deterioration present at the site. Through this paper, findings from material characterization studies will be presented, and a selection of conservation methodologies applied over the years will be summarized.
Manganese-enriched BLACK STAINING ON OUTDOOR STONE SURFACES: INVESTIGATION OF CAUSES, FORMATION, CHARACTERIZATION and potential treatment methods
Abstract
Black staining of stone monuments and architecture in outdoor settings is a relatively common phenomenon and has been found to result from a variety of different causes. In all cases, the blackening of the surface fundamentally alters the appearance of the stone and may affect legibility of surface carvings and façade details.
Examples of different sources leading to the formation of black surface patinas include pigment-producing cyanobacteria, manganese-oxidizing bioorganisms, and gypsum crusts on calcareous stone surfaces. Despite the varying mechanisms of surface darkening, all are a result of two fundamental factors: the stone composition itself and its interaction with the surrounding environment.
Desert varnish, a layer of black deposit which has been reported on the surfaces of rocks in arid climates, has been linked to the presence of manganese-oxidizing bacteria and fungi on the stone. Similar surface discoloration has also been observed in tropical regions and appears to be largely comprised of manganese oxide minerals. Moreover, these black patinas are also believed to be produced by manganese oxidizing bio-organisms. This paper explores the root sources of black, manganese-enriched staining on outdoor stone surfaces in both desert and tropical climates, in addition to identification and potential cleaning methods.
Black staining of stone monuments and architecture in outdoor settings is a relatively common phenomenon and has been found to result from a variety of different causes. In all cases, the blackening of the surface fundamentally alters the appearance of the stone and may affect legibility of surface carvings and façade details.
Examples of different sources leading to the formation of black surface patinas include pigment-producing cyanobacteria, manganese-oxidizing bioorganisms, and gypsum crusts on calcareous stone surfaces. Despite the varying mechanisms of surface darkening, all are a result of two fundamental factors: the stone composition itself and its interaction with the surrounding environment.
Desert varnish, a layer of black deposit which has been reported on the surfaces of rocks in arid climates, has been linked to the presence of manganese-oxidizing bacteria and fungi on the stone. Similar surface discoloration has also been observed in tropical regions and appears to be largely comprised of manganese oxide minerals. Moreover, these black patinas are also believed to be produced by manganese oxidizing bio-organisms. This paper explores the root sources of black, manganese-enriched staining on outdoor stone surfaces in both desert and tropical climates, in addition to identification and potential cleaning methods.
Characterization of lacquer, stone and plaster samples from Cambodia
Abstract
Eleven samples from Cambodian material culture were analyzed in order to determine the basic composition and structure of materials. Samples included:
A variety of analytical techniques were used, including fiber optic reflectance spectroscopy (FORS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), µ-Raman spectroscopy (µRS), attenuated total reflectance infrared spectroscopy (ATR-FTIR), X-ray powder diffraction (XRD), and petrographic analysis.
Eleven samples from Cambodian material culture were analyzed in order to determine the basic composition and structure of materials. Samples included:
- four paint/lacquer fragments and a sample of repair mortar taken from a pre-Angorian sculpture with traces of polychromy on display at the National Museum of Cambodia, Phnom Penh
- two plaster samples from Banteay Chhmar temple in Banteay Meanchey province (Northwest Cambodia)
- three plaster and stone samples from Preah Khan of Kampong Svay in Preah Vihear province (Northeast Cambodia)
- one stone sample from a pre-Angkorian stele originating from Takeo province (Southern Cambodia).
A variety of analytical techniques were used, including fiber optic reflectance spectroscopy (FORS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), µ-Raman spectroscopy (µRS), attenuated total reflectance infrared spectroscopy (ATR-FTIR), X-ray powder diffraction (XRD), and petrographic analysis.
Protein identification in cultural heritage via peptide mass fingerprinting
Abstract
Peptide mass fingerprinting (PMF) is a method that can be used to identify proteins. PMF utilizes targeted enzymatic digestion of proteins to cleave peptide bonds at specific amino acid sites, forming a unique peptide mixture. The peptide mixture is analyzed via spectrometric methods developed for the analysis of large molecules, typically Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). A mass spectrum indicating peptide sequences characteristic to the protein is produced, and can be compared with a reference database to identify the protein. With this technique, it is possible to characterize unknown proteins and trace their origins to the species level.
PMF was developed within the biological sciences as a way to efficiently and accurately identify proteins. It has interesting applications in cultural heritage studies, and although it requires destructive sampling, it is an extremely sensitive technique that can yield accurate results with very small sample sizes. Researchers have explored using PMF to identify proteinaceous binding materials, characterize proteins preserved within psuedomorphic corrosion products, and to analyze residues embedded within archaeological ceramics. Through this paper the fundamental principles of PMF and MALDI-TOF MS will be explored, as well as current research within cultural heritage employing these techniques.
Peptide mass fingerprinting (PMF) is a method that can be used to identify proteins. PMF utilizes targeted enzymatic digestion of proteins to cleave peptide bonds at specific amino acid sites, forming a unique peptide mixture. The peptide mixture is analyzed via spectrometric methods developed for the analysis of large molecules, typically Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). A mass spectrum indicating peptide sequences characteristic to the protein is produced, and can be compared with a reference database to identify the protein. With this technique, it is possible to characterize unknown proteins and trace their origins to the species level.
PMF was developed within the biological sciences as a way to efficiently and accurately identify proteins. It has interesting applications in cultural heritage studies, and although it requires destructive sampling, it is an extremely sensitive technique that can yield accurate results with very small sample sizes. Researchers have explored using PMF to identify proteinaceous binding materials, characterize proteins preserved within psuedomorphic corrosion products, and to analyze residues embedded within archaeological ceramics. Through this paper the fundamental principles of PMF and MALDI-TOF MS will be explored, as well as current research within cultural heritage employing these techniques.
Art in Transit: associated risks for artworks during travel and preventive measures to avoid them
Abstract
Preventive conservation is a term encompassing efforts to minimize or reduce the rate of deterioration for a wide range of collections materials. These efforts can include evaluating potential risks, employing appropriate temperature and humidity controls for the materials, and creating guidelines or procedures for handling, packing and transport. While it is generally understood that the safest place for artworks is within the climate-controlled environment of the museum, it is sometimes necessary for works of art to move to a different location. This may be related to rehousing initiatives, requiring the works to be transferred to an off-site storage location, or sending artwork to other institutions as a loan. The transportation of art can be a perilous task, subjecting the artwork to potential fluctuations in temperature and humidity, shock and vibration, and possible handling by non-specialists. Through this paper these risks will be addressed, as will investigations into preventative measures taken to minimize the potential for damage during transit.
Preventive conservation is a term encompassing efforts to minimize or reduce the rate of deterioration for a wide range of collections materials. These efforts can include evaluating potential risks, employing appropriate temperature and humidity controls for the materials, and creating guidelines or procedures for handling, packing and transport. While it is generally understood that the safest place for artworks is within the climate-controlled environment of the museum, it is sometimes necessary for works of art to move to a different location. This may be related to rehousing initiatives, requiring the works to be transferred to an off-site storage location, or sending artwork to other institutions as a loan. The transportation of art can be a perilous task, subjecting the artwork to potential fluctuations in temperature and humidity, shock and vibration, and possible handling by non-specialists. Through this paper these risks will be addressed, as will investigations into preventative measures taken to minimize the potential for damage during transit.
Use of Synthetic Adhesives in the Conservation of Wooden ArtifactS
Introduction
A wide variety of adhesives exist that are compatible with wood. These adhesives are typically grouped into two categories: natural and synthetic. Throughout history, natural protein derived adhesives such as animal glue from hides, fish, bones, and gelatin have been used, in addition to blood glues and casein. Some of the earliest evidence for the use of these proteinaceous adhesives on wooden object dates back to the 2nd – 3rd century BC. Their use continued to be widespread over time, and many are still used to this day.
With the beginnings of polymer science in the 1920’s, researchers began developing synthetic adhesives. Over the next 50 years, a wide range of synthetic adhesives became available for both industrial and commercial use. These adhesives touted a wide range of applications – from aircraft construction to product assembly to textiles. They are celebrated for their ability to bond “difficult” substrates, i.e. those that may not successfully bond with traditional adhesives. While the adhesives were well suited for these types of applications, they could also be used as alternatives to the natural adhesives traditionally used to bond less “difficult” surfaces as well. For the purposes of this report, the use of synthetic resins on wood will be the main focus.
In addition to commercial and home use, synthetic resins have found a place within the field of art conservation. Consumers and conservators now have access to a vast array of synthetic adhesives including acrylics, poly(vinyl) alcohol derivatives, epoxies, polyurethanes, polyester resins, elastomers, isocyanates, and hot melts. The choice of adhesive for use in conservation involves a more rigorous decision making process than is typically carried out by the hobbyist. A number of criteria must be considered before using these adhesives in conservation treatent. This includes understanding how the adhesive will interact with surrounding materials, aging characteristics, solubility, strength, reversibility or retreatability, and working properties such as carvability or paintability.
A wide variety of adhesives exist that are compatible with wood. These adhesives are typically grouped into two categories: natural and synthetic. Throughout history, natural protein derived adhesives such as animal glue from hides, fish, bones, and gelatin have been used, in addition to blood glues and casein. Some of the earliest evidence for the use of these proteinaceous adhesives on wooden object dates back to the 2nd – 3rd century BC. Their use continued to be widespread over time, and many are still used to this day.
With the beginnings of polymer science in the 1920’s, researchers began developing synthetic adhesives. Over the next 50 years, a wide range of synthetic adhesives became available for both industrial and commercial use. These adhesives touted a wide range of applications – from aircraft construction to product assembly to textiles. They are celebrated for their ability to bond “difficult” substrates, i.e. those that may not successfully bond with traditional adhesives. While the adhesives were well suited for these types of applications, they could also be used as alternatives to the natural adhesives traditionally used to bond less “difficult” surfaces as well. For the purposes of this report, the use of synthetic resins on wood will be the main focus.
In addition to commercial and home use, synthetic resins have found a place within the field of art conservation. Consumers and conservators now have access to a vast array of synthetic adhesives including acrylics, poly(vinyl) alcohol derivatives, epoxies, polyurethanes, polyester resins, elastomers, isocyanates, and hot melts. The choice of adhesive for use in conservation involves a more rigorous decision making process than is typically carried out by the hobbyist. A number of criteria must be considered before using these adhesives in conservation treatent. This includes understanding how the adhesive will interact with surrounding materials, aging characteristics, solubility, strength, reversibility or retreatability, and working properties such as carvability or paintability.
NEUTRON IMAGING AND X-RADIOGRAPHY: POTENTIAL APPLICATIONS IN ART AND ARCHAEOLOGY
Abstract
Neutron imaging and x-radiography are methods of non-destructive analysis which have been used to study cultural heritage objects. Both of these methods have the capability to produce 2D direct images as well as 3D reconstructed models. The two methods differ based on the type of radiation used – neutron imaging employs a stream of neutrons whereas x-radiography employs x-rays. These types of radiation have distinct interaction behaviors with matter, leading to the visualization of different information in resulting images. Researchers have found these methods to be complementary, especially in regard to the study of composite objects. Neutron imaging and x-radiography have been applied in the study of both art and archaeological materials.
This paper outlines the interaction behaviors of x-rays and neutrons with matter, and examines the different resulting images obtained using these techniques. Studies in which neutron imaging and x-radiography have been successfully utilized are discussed, as are potential limitations in utilizing these two imaging techniques. The limitations are primarily practical, as there are a limited number of neutron imaging facilities presently in operation. However, potential for generating radioactive isotopes during neutron imaging also exists. Risks of this potential are evaluated here with respect to cultural heritage materials.
Neutron imaging and x-radiography are methods of non-destructive analysis which have been used to study cultural heritage objects. Both of these methods have the capability to produce 2D direct images as well as 3D reconstructed models. The two methods differ based on the type of radiation used – neutron imaging employs a stream of neutrons whereas x-radiography employs x-rays. These types of radiation have distinct interaction behaviors with matter, leading to the visualization of different information in resulting images. Researchers have found these methods to be complementary, especially in regard to the study of composite objects. Neutron imaging and x-radiography have been applied in the study of both art and archaeological materials.
This paper outlines the interaction behaviors of x-rays and neutrons with matter, and examines the different resulting images obtained using these techniques. Studies in which neutron imaging and x-radiography have been successfully utilized are discussed, as are potential limitations in utilizing these two imaging techniques. The limitations are primarily practical, as there are a limited number of neutron imaging facilities presently in operation. However, potential for generating radioactive isotopes during neutron imaging also exists. Risks of this potential are evaluated here with respect to cultural heritage materials.
PROBING THE SACRED: ETHICAL CONSIDERATIONS IN THE SCIENTIFIC STUDY OF RELIGIOUS OBJECTS
Abstract
This paper aims to investigate ethical considerations that must be made during conservation analysis and study of religious objects within the museum. Although these objects have been removed from their original context, they likely still hold intangible significance. The authors propose that understanding these intangible aspects is an essential part of the study and holistic understanding of religious artworks. By looking at two different types of objects, Tibetan bronzes and Songye power figures, the authors seek to highlight some of the major ethical questions that arise throughout scientific or material investigation. Both types of sculpture are religious artifacts that often contain sacred materials within hidden channels or cavities, which are sealed within the object during a consecration ceremony or empowerment ritual. Despite these apparent similarities, consultation with source communities has revealed that the approach to investigation of interior contents and distribution of acquired knowledge differ significantly for the two types of objects. The authors use these examples to call attention to the larger question: how can museum professionals research, care for, and preserve religious artifacts responsibly?
This paper aims to investigate ethical considerations that must be made during conservation analysis and study of religious objects within the museum. Although these objects have been removed from their original context, they likely still hold intangible significance. The authors propose that understanding these intangible aspects is an essential part of the study and holistic understanding of religious artworks. By looking at two different types of objects, Tibetan bronzes and Songye power figures, the authors seek to highlight some of the major ethical questions that arise throughout scientific or material investigation. Both types of sculpture are religious artifacts that often contain sacred materials within hidden channels or cavities, which are sealed within the object during a consecration ceremony or empowerment ritual. Despite these apparent similarities, consultation with source communities has revealed that the approach to investigation of interior contents and distribution of acquired knowledge differ significantly for the two types of objects. The authors use these examples to call attention to the larger question: how can museum professionals research, care for, and preserve religious artifacts responsibly?